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Sample records for pretransplant graft irradiation

  1. Effect of total lymphoid irradiation and pretransplant blood transfusion on pancreatic islet allograft survival

    SciTech Connect

    Mendez-Picon, G.; McGeorge, M.

    1983-05-01

    Total lymphoid irradiation (TLI) has been shown to have a strong immunosuppressive effect both experimentally and clinically. Pretransplant blood transfusions have also been shown to have a strong beneficial effect in the outcome of organ transplantation. A study was made of the effect of TLI and pretransplant blood transfusions, alone and in combination, as an immunosuppressive modality in the isolated pancreatic islet transplant in the rat model. Donor rats (Fischer RT1v1) were kept on a 50% DL-ethionine supplemented diet for 4-6 weeks prior to pancreas removal. Recipient rats (Lewis RT1) were made diabetics prior to transplantation by iv injection of streptozotocin (45 mg/kg). Transfusion protocol consisted of a biweekly transfusion of 2 ml of either donor specific or third party transfusions. Total lymphoid irradiation was carried out by daily administration of 200 rads during one week prior to transplantation. Transplantation of the isolated islets was performed by intraportal injection. Syngeneic transplant of one and a half donor pancreata in each recipient reverted the diabetic condition indefinitely (greater than 100 days). Untreated allogenic grafts had a mean survival time (MST) of 5.2 days. Total lymphoid irradiation in dosages of 800, 1000, and 1200 rads, as the only immunosuppressive regimen, prolonged the MST of allografts to 15.3, 16.5, and 21.8 days, respectively (P less than .05). Pretransplant third party blood transfusion had no effect on allograft survival (MST 6.0). When donor specific blood transfusions were given, the MST was prolonged to 25.3 days (P less than .05). When TLI was administered to recipients of donor specific transfusions, the MST of the allografts did not show any statistical significant difference when compared with untreated animals. This abrogation of the beneficial effect of specific blood transfusion was observed in all dosages of TLI employed: 800 rad (MST 3.0), 1000 rad (MST 8.0), 1200 rad (MST 5.18).

  2. Pretransplant transcriptome profiles identify among kidneys with delayed graft function those with poorer quality and outcome.

    PubMed

    Mas, Valeria R; Scian, Mariano J; Archer, Kellie J; Suh, Jihee L; David, Krystle G; Ren, Qing; Gehr, Todd W B; King, Anne L; Posner, Marc P; Mueller, Thomas F; Maluf, Daniel G

    2011-01-01

    Robust biomarkers are needed to identify donor kidneys with poor quality associated with inferior early and longer-term outcome. The occurrence of delayed graft function (DGF) is most often used as a clinical outcome marker to capture poor kidney quality. Gene expression profiles of 92 preimplantation biopsies were evaluated in relation to DGF and estimated glomerular filtration rate (eGFR) to identify preoperative gene transcript changes associated with short-term function. Patients were stratified into those who required dialysis during the first week (DGF group) versus those without (noDGF group) and subclassified according to 1-month eGFR of >45 mL/min (eGFR(hi)) versus eGFR of ≤45 mL/min (eGFR(lo)). The groups and subgroups were compared in relation to clinical donor and recipient variables and transcriptome-associated biological pathways. A validation set was used to confirm target genes. Donor and recipient characteristics were similar between the DGF versus noDGF groups. A total of 206 probe sets were significant between groups (P < 0.01), but the gene functional analyses failed to identify any significantly affected pathways. However, the subclassification of the DGF and noDGF groups identified 283 probe sets to be significant among groups and associated with biological pathways. Kidneys that developed postoperative DGF and sustained an impaired 1-month function (DGF(lo) group) showed a transcriptome profile of significant immune activation already preimplant. In addition, these kidneys maintained a poorer transplant function throughout the first-year posttransplant. In conclusion, DGF is a poor marker for organ quality and transplant outcome. In contrast, preimplant gene expression profiles identify "poor quality" grafts and may eventually improve organ allocation.

  3. Pre-transplant portal vein thrombosis is an independent risk factor for graft loss due to hepatic artery thrombosis in liver transplant recipients

    PubMed Central

    Stine, Jonathan G.; Pelletier, Shawn J.; Schmitt, Timothy M.; Porte, Robert J.; Northup, Patrick G.

    2015-01-01

    Background Hepatic artery thrombosis is an uncommon but catastrophic complication following liver transplantation. We hypothesize that recipients with portal vein thrombosis are at increased risk. Methods Data on all liver transplants in the U.S. during the MELD era through September 2014 were obtained from UNOS. Status one, multivisceral, living donor, re-transplants, pediatric recipients and donation after cardiac death were excluded. Logistic regression models were constructed for hepatic artery thrombosis with resultant graft loss within 90 days of transplantation. Results 63,182 recipients underwent transplantation; 662 (1.1%) recipients had early hepatic artery thrombosis; of those, 91 (13.8%) had pre-transplant portal vein thrombosis, versus 7.5% with portal vein thrombosis but no hepatic artery thrombosis (p < 0.0001). Portal vein thrombosis was associated with an increased independent risk of hepatic artery thrombosis (OR 2.17, 95% CI 1.71–2.76, p < 0.001) as was donor risk index (OR 2.02, 95% CI 1.65–2.48, p < 0.001). Heparin use at cross clamp, INR, and male donors were all significantly associated with lower risk. Discussion Pre-transplant portal vein thrombosis is associated with post-transplant hepatic artery thrombosis independent of other factors. Recipients with portal vein thrombosis might benefit from aggressive coagulation management and careful donor selection. More research is needed to determine causal mechanism. PMID:27017168

  4. Dermal grafts to bony defects in irradiated and nonirradiated tissues

    SciTech Connect

    Lambert, P.M.; Patel, M.; Gutman, E.; Campana, H.A.

    1984-10-01

    Coverage of intraoral ablative defects presents many different problems. Free dermal grafts have been used to cover exposed mandibular bone in dogs. Grafts were placed in animals both before and after irradiation. Grafts were uniformly successful in animals not previously irradiated but failed when placed after irradiation.

  5. Prolonged bone marrow and skin allograft survival after pretransplant conditioning with cyclophosphamide and total lymphoid irradiation. [Mice

    SciTech Connect

    Kersey, J.H.; Kruger, J.; Song, C.; Kloster, B.

    1980-05-01

    Current studies were designed to provide long-term survival of allogeneic skin and bone marrow in mice preconditioned with various combinations of cyclophosphamide (CY) and/or total lymphoid irradiation (TLI). Long-term skin graft and bone marrow survival was obtained across the major histocompatibility barrier (BALB/c into C57BL/6) using pregrafting conditioning with either fractionated TLI or the combination of CY with a single dose of TLI. CY alone and a single dose of TLI alone were relatively ineffective as regrafting immunosuppressive combinations. Allogeneic bone marrow was required for long-term skin graft survival with either conditioning regimen. Allogeneic marrow transplantation resulted in somewhat more deaths than syngeneic transplantation with both CY + TLI and fractionated TLI.

  6. Influence of Deceased Donor and Pretransplant Recipient Parameters on Early Overall Kidney Graft-Survival in Germany.

    PubMed

    Fischer-Fröhlich, Carl-Ludwig; Kutschmann, Marcus; Feindt, Johanna; Schmidtmann, Irene; Kirste, Günter; Frühauf, Nils R; Wirges, Ulrike; Rahmel, Axel; Schleicher, Christina

    2015-01-01

    Background. Scarcity of grafts for kidney transplantation (KTX) caused an increased consideration of deceased donors with substantial risk factors. There is no agreement on which ones are detrimental for overall graft-survival. Therefore, we investigated in a nationwide multicentre study the impact of donor and recipient related risks known before KTX on graft-survival based on the original data used for allocation and graft acceptance. Methods. A nationwide deidentified multicenter study-database was created of data concerning kidneys donated and transplanted in Germany between 2006 and 2008 as provided by the national organ procurement organization (Deutsche Stiftung Organtransplantation) and BQS Institute. Multiple Cox regression (significance level 5%, hazard ratio [95% CI]) was conducted (n = 4411, isolated KTX). Results. Risk factors associated with graft-survival were donor age (1.020 [1.013-1.027] per year), donor size (0.985 [0.977-0.993] per cm), donor's creatinine at admission (1.002 [1.001-1.004] per µmol/L), donor treatment with catecholamine (0.757 [0.635-0.901]), and reduced graft-quality at procurement (1.549 [1.217-1.973]), as well as recipient age (1.012 [1.003-1.021] per year), actual panel reactive antibodies (1.007 [1.002-1.011] per percent), retransplantation (1.850 [1.484-2.306]), recipient's cardiovascular comorbidity (1.436 [1.212-1.701]), and use of IL2-receptor antibodies for induction (0.741 [0.619-0.887]). Conclusion. Some donor characteristics persist to impact graft-survival (e.g., age) while the effect of others could be mitigated by elaborate donor-recipient match and care.

  7. Postoperative irradiation of fresh autogenic cancellous bone grafts

    SciTech Connect

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

    1986-01-01

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

  8. Pre-transplant Evaluation of Donor Urinary Biomarkers can Predict Reduced Graft Function After Deceased Donor Kidney Transplantation.

    PubMed

    Koo, Tai Yeon; Jeong, Jong Cheol; Lee, Yonggu; Ko, Kwang-Pil; Lee, Kyoung-Bun; Lee, Sik; Park, Suk Joo; Park, Jae Berm; Han, Miyeon; Lim, Hye Jin; Ahn, Curie; Yang, Jaeseok

    2016-03-01

    Several recipient biomarkers are reported to predict graft dysfunction, but these are not useful in decision making for the acceptance or allocation of deceased donor kidneys; thus, it is necessary to develop donor biomarkers predictive of graft dysfunction. To address this issue, we prospectively enrolled 94 deceased donors and their 109 recipients who underwent transplantation between 2010 and 2013 at 4 Korean transplantation centers. We investigated the predictive values of donor urinary neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and L-type fatty acid binding protein (L-FABP) for reduced graft function (RGF). We also developed a prediction model of RGF using these donor biomarkers. RGF was defined as delayed or slow graft function. Multiple logistic regression analysis was used to generate a prediction model, which was internally validated using a bootstrapping method. Multiple linear regression analysis was used to assess the association of biomarkers with 1-year graft function. Notably, donor urinary NGAL levels were associated with donor AKI (P = 0.014), and donor urinary NGAL and L-FABP were predictive for RGF, with area under the receiver-operating characteristic curves (AUROC) of 0.758 and 0.704 for NGAL and L-FABP, respectively. The best-fit model including donor urinary NGAL, L-FABP, and serum creatinine conveyed a better predictive value for RGF than donor serum creatinine alone (P = 0.02). In addition, we generated a scoring method to predict RGF based on donor urinary NGAL, L-FABP, and serum creatinine levels. Diagnostic performance of the RGF prediction score (AUROC 0.808) was significantly better than that of the DGF calculator (AUROC 0.627) and the kidney donor profile index (AUROC 0.606). Donor urinary L-FABP levels were also predictive of 1-year graft function (P = 0.005). Collectively, these findings suggest donor urinary NGAL and L-FABP to be useful biomarkers for RGF, and support the use of

  9. Pre-transplant Evaluation of Donor Urinary Biomarkers can Predict Reduced Graft Function After Deceased Donor Kidney Transplantation.

    PubMed

    Koo, Tai Yeon; Jeong, Jong Cheol; Lee, Yonggu; Ko, Kwang-Pil; Lee, Kyoung-Bun; Lee, Sik; Park, Suk Joo; Park, Jae Berm; Han, Miyeon; Lim, Hye Jin; Ahn, Curie; Yang, Jaeseok

    2016-03-01

    Several recipient biomarkers are reported to predict graft dysfunction, but these are not useful in decision making for the acceptance or allocation of deceased donor kidneys; thus, it is necessary to develop donor biomarkers predictive of graft dysfunction. To address this issue, we prospectively enrolled 94 deceased donors and their 109 recipients who underwent transplantation between 2010 and 2013 at 4 Korean transplantation centers. We investigated the predictive values of donor urinary neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and L-type fatty acid binding protein (L-FABP) for reduced graft function (RGF). We also developed a prediction model of RGF using these donor biomarkers. RGF was defined as delayed or slow graft function. Multiple logistic regression analysis was used to generate a prediction model, which was internally validated using a bootstrapping method. Multiple linear regression analysis was used to assess the association of biomarkers with 1-year graft function. Notably, donor urinary NGAL levels were associated with donor AKI (P = 0.014), and donor urinary NGAL and L-FABP were predictive for RGF, with area under the receiver-operating characteristic curves (AUROC) of 0.758 and 0.704 for NGAL and L-FABP, respectively. The best-fit model including donor urinary NGAL, L-FABP, and serum creatinine conveyed a better predictive value for RGF than donor serum creatinine alone (P = 0.02). In addition, we generated a scoring method to predict RGF based on donor urinary NGAL, L-FABP, and serum creatinine levels. Diagnostic performance of the RGF prediction score (AUROC 0.808) was significantly better than that of the DGF calculator (AUROC 0.627) and the kidney donor profile index (AUROC 0.606). Donor urinary L-FABP levels were also predictive of 1-year graft function (P = 0.005). Collectively, these findings suggest donor urinary NGAL and L-FABP to be useful biomarkers for RGF, and support the use of

  10. Pre-transplant Evaluation of Donor Urinary Biomarkers can Predict Reduced Graft Function After Deceased Donor Kidney Transplantation

    PubMed Central

    Koo, Tai Yeon; Jeong, Jong Cheol; Lee, Yonggu; Ko, Kwang-Pil; Lee, Kyoung-Bun; Lee, Sik; Park, Suk Joo; Park, Jae Berm; Han, Miyeon; Lim, Hye Jin; Ahn, Curie; Yang, Jaeseok

    2016-01-01

    Abstract Several recipient biomarkers are reported to predict graft dysfunction, but these are not useful in decision making for the acceptance or allocation of deceased donor kidneys; thus, it is necessary to develop donor biomarkers predictive of graft dysfunction. To address this issue, we prospectively enrolled 94 deceased donors and their 109 recipients who underwent transplantation between 2010 and 2013 at 4 Korean transplantation centers. We investigated the predictive values of donor urinary neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and L-type fatty acid binding protein (L-FABP) for reduced graft function (RGF). We also developed a prediction model of RGF using these donor biomarkers. RGF was defined as delayed or slow graft function. Multiple logistic regression analysis was used to generate a prediction model, which was internally validated using a bootstrapping method. Multiple linear regression analysis was used to assess the association of biomarkers with 1-year graft function. Notably, donor urinary NGAL levels were associated with donor AKI (P = 0.014), and donor urinary NGAL and L-FABP were predictive for RGF, with area under the receiver-operating characteristic curves (AUROC) of 0.758 and 0.704 for NGAL and L-FABP, respectively. The best-fit model including donor urinary NGAL, L-FABP, and serum creatinine conveyed a better predictive value for RGF than donor serum creatinine alone (P = 0.02). In addition, we generated a scoring method to predict RGF based on donor urinary NGAL, L-FABP, and serum creatinine levels. Diagnostic performance of the RGF prediction score (AUROC 0.808) was significantly better than that of the DGF calculator (AUROC 0.627) and the kidney donor profile index (AUROC 0.606). Donor urinary L-FABP levels were also predictive of 1-year graft function (P = 0.005). Collectively, these findings suggest donor urinary NGAL and L-FABP to be useful biomarkers for RGF, and support

  11. Revascularization of autogenous skin grafts placed on irradiated tissue

    SciTech Connect

    Ueda, M.; Torii, S.; Kaneda, T.; Oka, T.

    1982-08-01

    Vascular changes in rat skin after irradiation were examined microangiographically. Revascularization of the skin transplanted during the chronic stage after irradiation was also studied. The results obtained through these examinations revealed higher vascular densities at the acute and the subacute stages, and low values at the chronic stages compared with those of the control. Furthermore, when the skin grafts were transplanted to the irradiated beds in the chronic stage, primary revascularization was scant, and the inhibited capillary proliferation in the recipient sites prevented new vessel penetration. This explains why grafts transplanted to previously irradiated beds fail to survive.

  12. Free and microvascular bone grafting in the irradiated dog mandible

    SciTech Connect

    Altobelli, D.E.; Lorente, C.A.; Handren, J.H. Jr.; Young, J.; Donoff, R.B.; May, J.W. Jr.

    1987-01-01

    Microvascular and free rib grafts were placed in 4.5 cm defects in an edentate mandibular body defect 18 to 28 days after completion of 50 Gy of irradiation from a /sup 60/Co source. The animals were sacrificed from two to forty weeks postoperatively and evaluated clinically, radiographically, and histologically. There was a marked difference in the alveolar mucosal viability with the two grafts. Mucosal dehiscence was not observed over any of the microvascular grafts, but was present in seven-eighths of the free grafts. Union of the microvascular bone graft to the host bone occurred within six weeks. In contrast, after six weeks the free graft was sequestered in all the animals. An unexpected finding with both types of graft was the marked subperiosteal bone formation. This bone appeared to be derived from the host bed, stabilizing and bridging the defects bilaterally. The results suggest that radiated periosteum may play an important role in osteogenesis.

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

    SciTech Connect

    Donald, P.J.

    1986-07-01

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

  14. Allograft tolerance in pigs after fractionated lymphoid irradiation. I. Skin grafts after partial lateral irradiation and bone marrow cell grafting

    SciTech Connect

    Vaiman, M.; Daburon, F.; Remy, J.; Villiers, P.A.; de Riberolles, C.; Lecompte, Y.; Mahouy, G.; Fradelizi, D.

    1981-05-01

    Experiments with pigs have been performed to establish bone marrow chimerism and skin graft tolerance between SLA genotyped animals. Recipients were conditioned by means of fractionated partial irradiation from lateral cobalt sources (partial lateral irradiation (PLI)). The head, neck, and lungs were protected with lead, the rest of the body being irradiated including the thymus, the majority of lymphoid organs with spleen, and most of the bone marrow sites.

  15. Albumin grafting on biomaterial surfaces using gamma-irradiation

    SciTech Connect

    Kamath, K.R.

    1993-01-01

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

  16. Effects of pre- and postoperative irradiation on the healing of bone grafts in the rabbit

    SciTech Connect

    Morales, M.J.; Marx, R.E.; Gottlieb, C.F.

    1987-01-01

    Healing of cellular bone grafts irradiated at various times in the postsurgical course was compared to the healing characteristics of bone grafts placed into already irradiated tissue and to controls of irradiated host mandible in a rabbit model. Physical graft consolidation was assessed by load stress characteristics and serial histologic examination. Results indicated that grafts placed into already irradiated tissues failed to form bone in both phases of expected regeneration resulting in structurally weakened and histologically deficient ossicles. Bone grafts irradiated after placement were tolerant of irradiation. Bone grafts irradiated after four weeks were found to be less affected by irradiation than those irradiated within the first four weeks, forming an ossicle structurally and histologically superior to that of bone ossicles developed from grafts placed into irradiated tissues.

  17. Pretransplant pulmonary function tests predict risk of mortality following fractionated total body irradiation and allogeneic peripheral blood stem cell transplant

    SciTech Connect

    Singh, Anurag K. . E-mail: singan@mail.nih.gov; Karimpour, Shervin E.; Savani, Bipin N.; Guion, Peter M.S.; Hope, Andrew J.; Mansueti, John R.; Ning, Holly; Altemus, Rosemary M. Ph.D.; Wu, Colin O.; Barrett, A. John

    2006-10-01

    Purpose: To determine the value of pulmonary function tests (PFTs) done before peripheral blood stem cell transplant (PBSCT) in predicting mortality after total body irradiation (TBI) performed with or without dose reduction to the lung. Methods and Materials: From 1997 to 2004, 146 consecutive patients with hematologic malignancies received fractionated TBI before PBSCT. With regimen A (n = 85), patients were treated without lung dose reduction to 13.6 gray (Gy). In regimen B (n = 35), total body dose was decreased to 12 Gy (1.5 Gy twice per day for 4 days) and lung dose was limited to 9 Gy by use of lung shielding. In regimen C (n = 26), lung dose was reduced to 6 Gy. All patients received PFTs before treatment, 90 days after treatment, and annually. Results: Median follow-up was 44 months (range, 12-90 months). Sixty-one patients had combined ventilation/diffusion capacity deficits defined as both a forced expiratory volume in the first second (FEV{sub 1}) and a diffusion capacity of carbon dioxide (DLCO) <100% predicted. In this group, there was a 20% improvement in one-year overall survival with lung dose reduction (70 vs. 50%, log-rank test p = 0.042). Conclusion: Among those with combined ventilation/diffusion capacity deficits, lung dose reduction during TBI significantly improved survival.

  18. Irradiation autogenous mandibular grafts in primary reconstructions

    SciTech Connect

    Hamaker, R.C.

    1981-07-01

    The procedure, irradiated mandibular autografts, for primary reconstruction, is presented with an immediate success rate of 88%. Eight cases have undergone primary mandibular reconstruction with the tumorous mandible irradiated to 10,000 rads in a single dose. The longest follow-up is 2 3/4 years. The autograft has proven to be an ideal implant. Major resections of the mandible in conjunction with large myocutaneous flaps have been reconstructed utilizing this implant.

  19. Excimer UV lamp irradiation induced grafting on synthetic polymers

    NASA Astrophysics Data System (ADS)

    Praschak, D.; Bahners, T.; Schollmeyer, E.

    Surface modifications on polyethyleneterephthalate (PET) films following excimer UV lamp irradiation induced grafting were studied. Characteristics of the modifications depending on the conditions during the irradiation were analysed using contact-angle measurements, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). Depending on the conditions during the irradiation different surface modifications were obtained, which can generally be classified regarding the hydrophilic or hydrophobic characteristics of the resulting surface. It is shown that not every substance that meets the general demands will be grafted on synthetic polymers using excimer UV radiation. Examples of agents that can simply be grafted onto polymer surfaces and those that undergo further crosslinking, building up thin films are listed. Agents used for grafting on polymers are 1,5-hexadiene, perfluoro-4-methyl-pent-2-ene, polyethyleneglycol 200, monosilane and polyethylene. The transferability of the effects achieved to substrates such as polyparaphenylene terephthalamide or polymetaphenylene isophthalamide is shown.

  20. Cellulose functionalization via high-energy irradiation-initiated grafting of glycidyl methacrylate and cyclodextrin immobilization

    NASA Astrophysics Data System (ADS)

    Desmet, Gilles; Takács, Erzsébet; Wojnárovits, László; Borsa, Judit

    2011-12-01

    Cotton-cellulose was functionalized using gamma-irradiation-induced grafting of glycidyl methacrylate (GMA) to obtain a hydrophobic cellulose derivative with epoxy groups suitable for further chemical modification. Two grafting techniques were applied. In pre-irradiation grafting (PIG) cellulose was irradiated in air and then immersed in a GMA monomer solution, whereas in simultaneous grafting (SG) cellulose was irradiated in an inert atmosphere in the presence of the monomer. PIG led to a more homogeneous fiber surface, while SG resulted in higher grafting yield but showed clear indications of some GMA-homopolymerization. Effects of the reaction parameters (grafting method, absorbed dose, monomer concentration, solvent composition) were evaluated by SEM, gravimetry (grafting yield) and FTIR spectroscopy. Water uptake of the cellulose decreased while adsorption of a pesticide molecule increased upon grafting. The adsorption was further enhanced by β-cyclodextrin immobilization during SG. This method can be applied to produce adsorbents from cellulose based agricultural wastes.

  1. A subset of gamma delta T-cell receptor-positive cells produce T-helper type-2 cytokines and regulate mouse skin graft rejection following portal venous pretransplant preimmunization.

    PubMed Central

    Gorczynski, R M; Chen, Z; Hoang, Y; Rossi-Bergman, B

    1996-01-01

    C3H/HeJ mice received B10.BR skin grafts following portal or lateral tail vein infusion of irradiated B10.BR spleen cells. Thereafter mice were injected with anti-alpha beta or anti-gamma delta T-cell receptor (TCR) monoclonal antibody (mAb). Anti-gamma delta TCR mAb abolished the increased graft survival afforded by portal venous (p.v.) immunization, and reversed the bias towards expression of mRNA for type-2 cytokines [interleukin-4 (IL-4), IL-10] seen in lymphoid tissue of p.v.-immunized mice. When gamma delta TCR+ and alpha beta TCR+ cells were isolated from the intestinal epithelial compartment (IEL), liver or Peyer's Patch (PP) of p.v.-immunized mice, the gamma delta TCR+ cells were found to be enriched in cells producing type-2 cytokines on rechallenge with irradiated B10.BR cells in vitro. gamma delta TCR+ cells from p.v.-immunized mice were further expanded in vitro with anti-CD3 and cytokines (combined IL-2 and IL-4). Following expansion these cells were capable of adoptively transferring increased B10.BR skin graft survival to naive mice, and continued to show a bias in type-2 cytokine synthesis after allostimulation in vitro. When gamma delta TCR chain expression was assessed in cells taken from p.v.-immunized mice, or in cells expanded in culture, our data suggest that p.v. immunization leads to oligoclonal, not polyclonal, expansion of those gamma delta TCR+ cells involved in inhibition of graft rejection. Images Figure 2 Figure 3 Figure 4 PMID:8778022

  2. Pretransplant Immune- and Apoptosis-Related Gene Expression Is Associated with Kidney Allograft Function

    PubMed Central

    Kamińska, Dorota; Kościelska-Kasprzak, Katarzyna; Chudoba, Paweł; Mazanowska, Oktawia; Banasik, Mirosław; Żabinska, Marcelina; Boratyńska, Maria; Lepiesza, Agnieszka; Gomółkiewicz, Agnieszka; Dzięgiel, Piotr; Klinger, Marian

    2016-01-01

    Renal transplant candidates present immune dysregulation, caused by chronic uremia. The aim of the study was to investigate whether pretransplant peripheral blood gene expression of immune factors affects clinical outcome of renal allograft recipients. Methods. In a prospective study, we analyzed pretransplant peripheral blood gene expression in87 renal transplant candidates with real-time PCR on custom-designed low density arrays (TaqMan). Results. Immediate posttransplant graft function (14-day GFR) was influenced negatively by TGFB1 (P = 0.039) and positively by IL-2 gene expression (P = 0.040). Pretransplant blood mRNA expression of apoptosis-related genes (CASP3, FAS, and IL-18) and Th1-derived cytokine gene IFNG correlated positively with short- (6-month GFR CASP3: P = 0.027, FAS: P = 0.021, and IFNG: P = 0.029) and long-term graft function (24-month GFR CASP3: P = 0.003, FAS: P = 0.033, IL-18: P = 0.044, and IFNG: P = 0.04). Conclusion. Lowered pretransplant Th1-derived cytokine and apoptosis-related gene expressions were a hallmark of subsequent worse kidney function but not of acute rejection rate. The pretransplant IFNG and CASP3 and FAS and IL-18 genes' expression in the recipients' peripheral blood is the possible candidate for novel biomarker of short- and long-term allograft function. PMID:27382192

  3. Grafting of HEMA onto dopamine coated stainless steel by 60Co-γ irradiation method

    NASA Astrophysics Data System (ADS)

    Jin, Wanqin; Yang, Liming; Yang, Wei; Chen, Bin; Chen, Jie

    2014-12-01

    A novel method for grafting of 2-hydroxyethyl methacrylate (HEMA) onto the surface of stainless steel (SS) was explored by using 60Co-γ irradiation. The surface of SS was modified by coating of dopamine before radiation grafting. The grafting reaction was performed in a simultaneous irradiation condition. The chemical structures change of the surface before and after grafting was demonstrated by Fourier transform infrared (FTIR) spectrometer. The hydrophilicity of the samples was determined by water contact angle measurement in the comparison of the stainless steel in the conditions of pristine, dopamine coated and HEMA grafted. Surface morphology of the samples was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The corrosion resistance properties of the samples were evaluated by Tafel polarization curve. The hemocompatibility of the samples were tested by platelet adhesion assay.

  4. RECIPIENT PRETRANSPLANT INOSINE MONOPHOSPHATE DEHYDROGENASE ACTIVITY IN NONMYELOABLATIVE HCT

    PubMed Central

    Bemer, Meagan J.; Risler, Linda J.; Phillips, Brian R.; Wang, Joanne; Storer, Barry E.; Sandmaier, Brenda M.; Duan, Haichuan; Raccor, Brianne S.; Boeckh, Michael J.; McCune, Jeannine S.

    2014-01-01

    Mycophenolic acid, the active metabolite of mycophenolate mofetil (MMF), inhibits inosine monophosphate dehydrogenase (IMPDH) activity. IMPDH is the rate-limiting enzyme involved in de novo synthesis of guanosine nucleotides and catalyzes the oxidation of inosine 5’- monophosphate (IMP) to xanthosine 5’-monophosphate (XMP). We developed a highly sensitive liquid chromatography–mass spectrometry method to quantitate XMP concentrations in peripheral blood mononuclear cells (PMNC) isolated from the recipient pretransplant and used this method to determine IMPDH activity in 86 nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) patients. The incubation procedure and analytical method yielded acceptable within-sample and within-individual variability. Considerable between-individual variability was observed (12.2-fold). Low recipient pretransplant IMPDH activity was associated with increased day +28 donor T-cell chimerism, more acute graft-versus-host disease (GVHD), lower neutrophil nadirs, and more cytomegalovirus reactivation, but not with chronic GVHD, relapse, non-relapse mortality, or overall mortality. We conclude that quantitation of the recipient’s pretransplant IMPDH activity in PMNC lysate could provide a useful biomarker to evaluate a recipient’s sensitivity to MMF, but confirmatory studies are needed. Further trials should be conducted to confirm our findings and to optimize postgrafting immunosuppression in nonmyeloablative HCT recipients. PMID:24923537

  5. Lung function after bone marrow grafting

    SciTech Connect

    Depledge, M.H.; Barrett, A.; Powles, R.L.

    1983-02-01

    Results of a prospective lung function study are presented for 48 patients with acute myeloid leukemia (AML) treated with total body irradiation (TBI) and bone marrow transplantation (BMT) at the Royal Marsden Hospital between 1978 and 1980. Patients with active disease or who were in remission following cytoreductive chemotherapy had mildly impaired gas exchange prior to grafting. After TBI and BMT all patients studied developed progressive deterioration of lung function during the first 100 days, although these changes were subclinical. Infection and graft-versus-host disease (GvHD) were associated with further worsening of restrictive ventilatory defects and diffusing capacity (D/sub L/CO). Beyond 100 days, ventilatory ability returned to normal and gas transfer improved, although it failed to reach pre-transplant levels. There was no evidence of progressive pulmonary fibrosis during the first year after grafting.

  6. Pre-Transplant Cardiovascular Risk Factors Affect Kidney Allograft Survival: A Multi-Center Study in Korea

    PubMed Central

    Lee, Jung Pyo; Bae, Eunjin; Kang, Eunjeong; Kim, Hack-Lyoung; Kim, Yong-Jin; Oh, Yun Kyu; Kim, Yon Su; Kim, Young Hoon; Lim, Chun Soo

    2016-01-01

    Background Pre-transplant cardiovascular (CV) risk factors affect the development of CV events even after successful kidney transplantation (KT). However, the impact of pre-transplant CV risk factors on allograft failure (GF) has not been reported. Methods and Findings We analyzed the graft outcomes of 2,902 KT recipients who were enrolled in a multi-center cohort from 1997 to 2012. We calculated the pre-transplant CV risk scores based on the Framingham risk model using age, gender, total cholesterol level, smoking status, and history of hypertension. Vascular disease (a composite of ischemic heart disease, peripheral vascular disease, and cerebrovascular disease) was noted in 6.5% of the patients. During the median follow-up of 6.4 years, 286 (9.9%) patients had developed GF. In the multivariable-adjusted Cox proportional hazard model, pre-transplant vascular disease was associated with an increased risk of GF (HR 2.51; 95% CI 1.66–3.80). The HR for GF (comparing the highest with the lowest tertile regarding the pre-transplant CV risk scores) was 1.65 (95% CI 1.22–2.23). In the competing risk model, both pre-transplant vascular disease and CV risk score were independent risk factors for GF. Moreover, the addition of the CV risk score, the pre-transplant vascular disease, or both had a better predictability for GF compared to the traditional GF risk factors. Conclusions In conclusion, both vascular disease and pre-transplant CV risk score were independently associated with GF in this multi-center study. Pre-transplant CV risk assessments could be useful in predicting GF in KT recipients. PMID:27501048

  7. Free bone graft reconstruction of irradiated facial tissue: Experimental effects of basic fibroblast growth factor stimulation

    SciTech Connect

    Eppley, B.L.; Connolly, D.T.; Winkelmann, T.; Sadove, A.M.; Heuvelman, D.; Feder, J. )

    1991-07-01

    A study was undertaken to evaluate the potential utility of basic fibroblast growth factor in the induction of angiogenesis and osseous healing in bone previously exposed to high doses of irradiation. Thirty New Zealand rabbits were evaluated by introducing basic fibroblast growth factor into irradiated mandibular resection sites either prior to or simultaneous with reconstruction by corticocancellous autografts harvested from the ilium. The fate of the free bone grafts was then evaluated at 90 days postoperatively by microangiographic, histologic, and fluorochrome bone-labeling techniques. Sequestration, necrosis, and failure to heal to recipient osseous margins was observed both clinically and histologically in all nontreated irradiated graft sites as well as those receiving simultaneous angiogenic stimulation at the time of graft placement. No fluorescent activity was seen in these graft groups. In the recipient sites pretreated with basic fibroblast growth factor prior to placement of the graft, healing and reestablishment of mandibular contour occurred in nearly 50 percent of the animals. Active bone formation was evident at cortical margins adjacent to the recipient sites but was absent in the more central cancellous regions of the grafts.

  8. Pre-transplant dialysis modality does not influence short- or long-term outcome in kidney transplant recipients: analysis of paired kidneys from the same deceased donor.

    PubMed

    Dipalma, Teresa; Fernández-Ruiz, Mario; Praga, Manuel; Polanco, Natalia; González, Esther; Gutiérrez-Solis, Elena; Gutiérrez, Eduardo; Andrés, Amado

    2016-09-01

    Previous studies have reported contradictory results regarding the effect of pre-transplant dialysis modality on the outcomes after kidney transplantation (KT). To minimize the confounding effect of donor-related variables, we performed a donor-matched retrospective comparison of 160 patients that received only one modality of pre-transplant dialysis (peritoneal dialysis [PD] and hemodialysis [HD] in 80 patients each) and that subsequently underwent KT at our center between January 1990 and December 2007. Cox regression models were used to evaluate the association between pre-transplant dialysis modality and primary study outcomes (death-censored graft survival and patient survival). To control for imbalances in recipient-related baseline characteristics, we performed additional adjustments for the propensity score (PS) for receiving pre-transplant PD (versus HD). There were no significant differences according to pre-transplant dialysis modality in death-censored graft survival (PS-adjusted hazard ratio [aHR]: 0.65; 95% confidence interval [95% CI]: 0.25-1.68) or patient survival (aHR: 0.58; 95% CI: 0.13-2.68). There were no differences in 10-year graft function or in the incidence of post-transplant complications either, except for a higher risk of lymphocele in patients undergoing PD (odds ratio: 4.31; 95% CI: 1.15-16.21). In conclusion, pre-transplant dialysis modality in KT recipients does not impact short- or long-term graft outcomes or patient survival.

  9. Effects of extra irradiation on surface and bulk properties of PMPC-grafted cross-linked polyethylene.

    PubMed

    Yamane, Shihori; Kyomoto, Masayuki; Moro, Toru; Watanabe, Kenichi; Hashimoto, Masami; Takatori, Yoshio; Tanaka, Sakae; Ishihara, Kazuhiko

    2016-01-01

    Sterilization using high-energy irradiation is an important aspect of implementing an ultra-high molecular weight polyethylene acetabular liner in total hip arthroplasty (THA). In this study, we evaluate the effects of extra irradiations such as gamma-ray or plasma irradiation during sterilization of the poly(2-methacryloyloxyethyl phosphorylcholine [MPC]) (PMPC) surface and cross-linked polyethylene (CLPE) substrate of a PMPC-grafted CLPE acetabular liner. The PMPC-grafted surface yielded high wettability and low friction properties regardless of the extra irradiations as compared with untreated CLPE. During a hip simulator test, wear resistance of the PMPC-grafted CLPE liner was maintained after extra irradiation, which is due to the high wettability characteristics of the PMPC surface. In particular, the PMPC-grafted CLPE liner treated with plasma irradiation showed greater wettability and wear resistance than that with gamma-ray irradiation. However, we could not clearly observe the changes in chemical properties and morphology of the PMPC surface after both extra irradiations. The physical and mechanical properties attributed to CLPE substrate performance were also unchanged. In contrast, PMPC-grafted CLPE treated with plasma irradiation showed improved oxidation resistance as compared to that treated with gamma-ray irradiation after accelerated aging. Thus, we conclude that PMPC-grafted CLPE with plasma irradiation has promise as a lifelong solution for bearing in THA. PMID:26148654

  10. Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile. I. Effect of γ-irradiation on grafting parameters

    NASA Astrophysics Data System (ADS)

    Kiatkamjornwong, S.; Chvajarernpun, J.; Nakason, C.

    1993-07-01

    Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85°C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to gamma-rays. A thin aluminum foil was used to cover the inner wall of the reaction vessel, so that the homopolymer concentration was reduced to be less than 1.0% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmation of graft copolymerization and saponification reactions was made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the total dose on the extent of the grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.

  11. Associations of Pre-Transplant Serum Albumin with Post-Transplant Outcomes in Kidney Transplant Recipients

    PubMed Central

    Molnar, Miklos Z; Kovesdy, Csaba P; Bunnapradist, Suphamai; Streja, Elani; Mehrotra, Rajnish; Krishnan, Mahesh; Nissenson, Allen R; Kalantar-Zadeh, Kamyar

    2011-01-01

    The association between pre-transplant serum albumin concentration and post-transplant outcomes in kidney transplant recipients is unclear. We hypothesized that in transplant-waitlisted hemodialysis patients, lower serum albumin concentrations are associated with worse post-transplant outcomes. Linking the 5-year patient data of a large dialysis organization (DaVita) to the Scientific Registry of Transplant Recipients, we identified 8961 hemodialysis patients who underwent first kidney transplantation. Mortality or graft failure and delayed graft function (DGF) risks were estimated by Cox regression (hazard ratio [HR]) and logistic regression (Odds ratio [OR]), respectively. Patients were 48±13 years old and included 37% women and 27% diabetics. The higher pre-transplant serum albumin was associated with lower mortality, graft failure and DGF risk even after multivariate adjustment for case-mix, malnutrition-inflammation complex and transplant related variable. Every 0.2 g/dL higher pre-transplant serum albumin concentration was associated with 13% lower all-cause mortality (HR=0.87 [95% confidence interval: 0.82-0.93]), 17% lower cardiovascular mortality (HR=0.83[0.74-0.93]), 7% lower combined risk of death or graft failure (HR=0.93[0.89-0.97]), and 4% lower DGF risk (OR=0.96[0.93-0.99]). Hence, lower pre-transplant serum albumin level is associated with worse post-transplant outcomes. Clinical trials to examine interventions to improve nutritional status in transplant-wait-listed hemodialysis patients and their impacts on post-transplant outcomes are indicated. PMID:21449945

  12. Fetal hypothalamic transplants into brain irradiated rats: Graft morphometry and host behavioral responses

    SciTech Connect

    Pearlman, S.H.; Rubin, P.; White, H.C.; Wiegand, S.J.; Gash, D.M. )

    1990-08-01

    This study was designed to test the hypothesis that neural implants can ameliorate or prevent some of the long-term changes associated with CNS irradiation. Using a rat model, the initial study focused on establishing motor, regulatory, and morphological changes associated with brain radiation treatments. Secondly, fetal hypothalamic tissue grafts were placed into the third ventricle of rats which had been previously irradiated. Adult male Long Evans rats received one of three radiation doses (15, 22.5, 30 Gy) or no radiation. Three days after irradiation, 7 animals in each dose group received an embryonic day 17 hypothalamic graft into the third ventricle while the remaining 8-9 animals in each group received injections of vehicle solution (sham). Few changes were observed in the 15 and 22.5 Gy animals, however rats in the 30 Gy treatment group showed stereotypic and ambulatory behavioral hyperactivity 32 weeks after irradiation. Regulatory changes in the high dose group included decreased growth rate and decreased urine osmolalities, but these measures were extremely variable among animals. Morphological results demonstrated that 30 Gy irradiated animals showed extensive necrosis primarily in the fimbria, which extended into the internal capsule, optic nerve, hippocampus, and thalamus. Hemorrhages were found in the hippocampus, thalamus, and fimbria. Defects in the blood-brain barrier also were evident by entry of intravascularly injected horseradish peroxidase into the parenchyma of the brain. Animals in the 30 Gy grafted group showed fewer behavioral changes and less brain damage than their sham grafted counterparts. Specifically, activity measures were comparable to normal levels, and a dilute urine was not found in the 30 Gy implanted rats. Morphological changes support these behavioral results since only two 30 Gy implanted rats showed necrosis.

  13. Tube shunt coverage with gamma-irradiated cornea allograft (VisionGraft)

    PubMed Central

    Ekici, Feyzahan; Moster, Marlene R; Cvintal, Victor; Hu, Wanda D; Waisbourd, Michael

    2015-01-01

    Purpose To investigate the clinical outcomes of tube shunt coverage using sterile gamma-irradiated cornea allograft. Patients and methods The Wills Eye Hospital Glaucoma Research Center retrospectively reviewed the medical records of 165 patients who underwent glaucoma tube shunt procedures using sterile gamma-irradiated cornea allograft (VisionGraft) between December 2012 and November 2013. Demographic characteristics, type of tube shunt, and position were noted. Complications were recorded at 1 day; 1 week; 1, 3, 6, and 12 months; and on the final postoperative visit. Results One hundred and sixty-nine eyes of 165 patients were included. The mean follow-up time was 4.8±3.5 (ranging from 1 to 16) months. There was no evidence of immunological reaction, infection, or exposure in 166 eyes (98.2%). Three eyes (1.8%) experienced graft or tube exposure within the first 3 postoperative months. Two of the cases had underlying diseases: bullous pemphigoid and chronic allergic conjunctivitis. Conclusion Coverage of tube shunts using gamma-irradiated cornea allograft had a low exposure rate and was well tolerated. The graft can be stored long term at room temperature and has an excellent postoperative cosmetic appearance. PMID:25995612

  14. Recipient NK cell inactivation and intestinal barrier loss are required for MHC-matched graft-versus-host disease.

    PubMed

    Nalle, Sam C; Kwak, H Aimee; Edelblum, Karen L; Joseph, Nora E; Singh, Gurminder; Khramtsova, Galina F; Mortenson, Eric D; Savage, Peter A; Turner, Jerrold R

    2014-07-01

    Previous studies have shown a correlation between pretransplant conditioning intensity, intestinal barrier loss, and graft-versus-host disease (GVHD) severity. However, because irradiation and other forms of pretransplant conditioning have pleiotropic effects, the precise role of intestinal barrier loss in GVHD pathogenesis remains unclear. We developed GVHD models that allowed us to isolate the specific contributions of distinct pretransplant variables. Intestinal damage was required for the induction of minor mismatch [major histocompatibility complex (MHC)-matched] GVHD, but was not necessary for major mismatch GVHD, demonstrating fundamental pathogenic distinctions between these forms of disease. Moreover, recipient natural killer (NK) cells prevented minor mismatch GVHD by limiting expansion and target organ infiltration of alloreactive T cells via a perforin-dependent mechanism, revealing an immunoregulatory function of MHC-matched recipient NK cells in GVHD. Minor mismatch GVHD required MyD88-mediated Toll-like receptor 4 (TLR4) signaling on donor cells, and intestinal damage could be bypassed by parenteral lipopolysaccharide (LPS) administration, indicating a critical role for the influx of bacterial components triggered by intestinal barrier loss. In all, the data demonstrate that pretransplant conditioning plays a dual role in promoting minor mismatch GVHD by both depleting recipient NK cells and inducing intestinal barrier loss.

  15. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    NASA Astrophysics Data System (ADS)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  16. Solvent effect on post-irradiation grafting of styrene onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) films

    NASA Astrophysics Data System (ADS)

    Napoleão Geraldes, Adriana; Augusto Zen, Heloísa; Ribeiro, Geise; Fernandes Parra, Duclerc; Benévolo Lugão, Ademar

    2013-03-01

    Radiation-induced grafting of styrene onto ETFE films in different solvent was investigated after simultaneous irradiation (in post-irradiation condition) using a 60Co source. Grafting of styrene followed by sulfonation onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) are currently studied for synthesis of ion exchange membranes. The ETFE films were immersed in styrene/toluene, styrene/methanol and styrene/isopropyl alcohol and irradiated at 20 and 100 kGy doses at room temperature. The post-irradiation time was established at 14 day and the grafting degree was evaluated. The grafted films were sulfonated using chlorosulfonic acid and 1,2-dichloroethane 20:80 (v/v) at room temperature for 5 h. The degree of grafting (DOG) was determined gravimetrically and physical or chemical changes were evaluated by differential scanning calorimeter analysis (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The ion exchange capacity (IEC) values showed the best performance of sulfonation for ETFE membranes grafted in toluene solvent. Surface images of the grafted films by SEM technique have presented a strong effect of the solvents on the films morphology.

  17. Graft polymerization of guar gum with acryl amide irradiated by microwaves for colonic drug delivery.

    PubMed

    Shahid, Muhammad; Bukhari, Shazia Anwer; Gul, Yousra; Munir, Hira; Anjum, Fozia; Zuber, Mohammad; Jamil, Tahir; Zia, Khalid Mahmood

    2013-11-01

    This article is aimed to discuss the modification of guar gum through microwave irradiation by varying the time of irradiation. The characterization of the modified products was carried out using FTIR spectroscopic analysis. The FT-IR spectrum of the pure guar gum (GG) sample showed a broad peak at 3298 cm(-1) while the modified GG sample displayed a peak at 1541 cm(-1) which was absent in the crude sample. The X-ray diffraction (XRD) analysis confirmed the increase in crystallinity due to grafting of the sample with polyacrylamide (GG-g-PAM). Scanning electron microscope (SEM) images revealed that granular form of guar gum was changed into fibrillar structure after grafting. Thermo-gravimetric analysis of the modified samples was also carried out and discussed. The role of guar gum as a matrix for controlled release of drug triamcinolone was evaluated. The GG-acrylamide grafted samples presented a correlation between drug release and time of microwave exposure. The results revealed that such modified product has potential applications in colonic drug delivery system.

  18. Synthesis of perm-selective membranes by grafting acrylic acid into air-irradiated Teflon-FEP films

    NASA Astrophysics Data System (ADS)

    Bozzi, Annick; Chapiro, Adolphe

    Grafting acrylic acid into air-irradiated Teflon-FEP films was investigated. Pre-irradiation doses ranged from 0.5 to 10 kGy. Grafting occurred at 45 or 60°C. Homopolymerization inhibitors, ferrous ions or methylene blue, were added to the system. It was found that after completion of the reaction, within 40-100 min, membranes were obtained with very low electric resistivities. The influence of added inhibitors, pre-irradiation dose and grafting temperature was studied. From the results it is concluded that the initiating centers in air-irradiated Teflon-FEP are, on the one hand, peroxides of structure POOP', in which P is a polymeric radical and Pprime; a small fragment, and on the other trapped PO .2 radicals. The latter only react after losing their oxygen. In the presence of polymerization inhibitors, initiation involves a redox process which reduces the overall activation energy.

  19. Grafting acrylic acid onto polypropylene by reactive extrusion with pre-irradiated PP as initiator

    NASA Astrophysics Data System (ADS)

    Cai, Chuanlun; Shi, Qiang; Li, Lili; Zhu, Lianchao; Yin, Jinghua

    2008-03-01

    In this paper, the modification of polypropylene (PP) with acrylic acid (AA) by reactive extrusion using pre-irradiated PP (rPP) as initiator was investigated. It was found the relatively high graft degree (Gd) and slight degradation of modified PP was obtained when 20 wt% rPP was used. This result can be explained in terms of effective concentration of free radicals. Compared with the neat PP, the modified PP showed the high-notched impact strength and improved adhesion of PP to polar substrate. This technique is of potential industrial interest for PP modification.

  20. Autologous Fat Grafting Reduces Pain in Irradiated Breast: A Review of Our Experience

    PubMed Central

    Caviggioli, Fabio; Maione, Luca; Klinger, Francesco; Lisa, Andrea; Klinger, Marco

    2016-01-01

    Introduction. Pain syndromes affect women after conservative and radical breast oncological procedures. Radiation therapy influences their development. We report autologous fat grafting therapeutical role in treating chronic pain in irradiated patients. Materials and Methods. From February 2006 to November 2014, we collect a total of 209 patients who meet the definition of “Postmastectomy Pain Syndrome” (PMPS) and had undergone mastectomy with axillary dissection (113 patients) or quadrantectomy (96 patients). Both procedures were followed by radiotherapy. We performed fat grafting following Coleman's procedure. Mean amount of adipose tissue injected was 52 cc (±8.9 cc) per breast. Seventy-eight in 209 patients were not treated surgically and were considered as control group. Data were gathered through preoperative and postoperative VAS questionnaires; analgesic drug intake was recorded. Results. The follow-up was at 12 months (range 11.7–13.5 months). In 120 treated patients we detected pain decrease (mean ± SD point reduction, 3.19 ± 2.86). Forty-eight in 59 patients stopped their analgesic drug therapy. Controls reported a mean ± SD decrease of pain of 1.14 ± 2.72. Results showed that pain decreased significantly in patients treated (p < 0.005, Wilcoxon rank-sum test). Conclusion. Our 8-year experience confirms fat grafting effectiveness in decreasing neuropathic pain. PMID:26858758

  1. Autologous Fat Grafting Reduces Pain in Irradiated Breast: A Review of Our Experience.

    PubMed

    Caviggioli, Fabio; Maione, Luca; Klinger, Francesco; Lisa, Andrea; Klinger, Marco

    2016-01-01

    Introduction. Pain syndromes affect women after conservative and radical breast oncological procedures. Radiation therapy influences their development. We report autologous fat grafting therapeutical role in treating chronic pain in irradiated patients. Materials and Methods. From February 2006 to November 2014, we collect a total of 209 patients who meet the definition of "Postmastectomy Pain Syndrome" (PMPS) and had undergone mastectomy with axillary dissection (113 patients) or quadrantectomy (96 patients). Both procedures were followed by radiotherapy. We performed fat grafting following Coleman's procedure. Mean amount of adipose tissue injected was 52 cc (±8.9 cc) per breast. Seventy-eight in 209 patients were not treated surgically and were considered as control group. Data were gathered through preoperative and postoperative VAS questionnaires; analgesic drug intake was recorded. Results. The follow-up was at 12 months (range 11.7-13.5 months). In 120 treated patients we detected pain decrease (mean ± SD point reduction, 3.19 ± 2.86). Forty-eight in 59 patients stopped their analgesic drug therapy. Controls reported a mean ± SD decrease of pain of 1.14 ± 2.72. Results showed that pain decreased significantly in patients treated (p < 0.005, Wilcoxon rank-sum test). Conclusion. Our 8-year experience confirms fat grafting effectiveness in decreasing neuropathic pain.

  2. Recipient pretransplant inosine monophosphate dehydrogenase activity in nonmyeloablative hematopoietic cell transplantation.

    PubMed

    Bemer, Meagan J; Risler, Linda J; Phillips, Brian R; Wang, Joanne; Storer, Barry E; Sandmaier, Brenda M; Duan, Haichuan; Raccor, Brianne S; Boeckh, Michael J; McCune, Jeannine S

    2014-10-01

    Mycophenolic acid, the active metabolite of mycophenolate mofetil (MMF), inhibits inosine monophosphate dehydrogenase (IMPDH) activity. IMPDH is the rate-limiting enzyme involved in de novo synthesis of guanosine nucleotides and catalyzes the oxidation of inosine 5'-monophosphate to xanthosine 5'-monophosphate (XMP). We developed a highly sensitive liquid chromatography-mass spectrometry method to quantitate XMP concentrations in peripheral blood mononuclear cells (PMNCs) isolated from the recipient pretransplant and used this method to determine IMPDH activity in 86 nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) patients. The incubation procedure and analytical method yielded acceptable within-sample and within-individual variability. Considerable between-individual variability was observed (12.2-fold). Low recipient pretransplant IMPDH activity was associated with increased day +28 donor T cell chimerism, more acute graft-versus-host disease (GVHD), lower neutrophil nadirs, and more cytomegalovirus reactivation but not with chronic GVHD, relapse, nonrelapse mortality, or overall mortality. We conclude that quantitation of the recipient's pretransplant IMPDH activity in PMNC lysate could provide a useful biomarker to evaluate a recipient's sensitivity to MMF. Further trials should be conducted to confirm our findings and to optimize postgrafting immunosuppression in nonmyeloablative HCT recipients.

  3. Recipient pretransplant inosine monophosphate dehydrogenase activity in nonmyeloablative hematopoietic cell transplantation.

    PubMed

    Bemer, Meagan J; Risler, Linda J; Phillips, Brian R; Wang, Joanne; Storer, Barry E; Sandmaier, Brenda M; Duan, Haichuan; Raccor, Brianne S; Boeckh, Michael J; McCune, Jeannine S

    2014-10-01

    Mycophenolic acid, the active metabolite of mycophenolate mofetil (MMF), inhibits inosine monophosphate dehydrogenase (IMPDH) activity. IMPDH is the rate-limiting enzyme involved in de novo synthesis of guanosine nucleotides and catalyzes the oxidation of inosine 5'-monophosphate to xanthosine 5'-monophosphate (XMP). We developed a highly sensitive liquid chromatography-mass spectrometry method to quantitate XMP concentrations in peripheral blood mononuclear cells (PMNCs) isolated from the recipient pretransplant and used this method to determine IMPDH activity in 86 nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) patients. The incubation procedure and analytical method yielded acceptable within-sample and within-individual variability. Considerable between-individual variability was observed (12.2-fold). Low recipient pretransplant IMPDH activity was associated with increased day +28 donor T cell chimerism, more acute graft-versus-host disease (GVHD), lower neutrophil nadirs, and more cytomegalovirus reactivation but not with chronic GVHD, relapse, nonrelapse mortality, or overall mortality. We conclude that quantitation of the recipient's pretransplant IMPDH activity in PMNC lysate could provide a useful biomarker to evaluate a recipient's sensitivity to MMF. Further trials should be conducted to confirm our findings and to optimize postgrafting immunosuppression in nonmyeloablative HCT recipients. PMID:24923537

  4. Equal overall rejection rate in pre-transplant flow-cytometric cross-match negative and positive adult recipients in liver transplantation.

    PubMed

    Matinlauri, Irma H; Höckerstedt, Krister A; Isoniemi, Helena M

    2005-10-01

    T cell IgG flow-cytometric cross-matches (FCXM) using 48 stored pre-transplant patient serum samples and 40 stored serum samples collected 3 wk after liver transplantation and frozen spleen cells of cadaveric donors in 48 consecutive liver transplantations were performed retrospectively. T cell IgG FCXM using pre-transplant serum samples was compared with 46 complement-dependent lymphocytotoxic cross-matches (CDCXM) performed at the time of transplantation. Clinical relevance of these tests was evaluated in relation to acute rejection, 1-, 3- and 5-yr graft and patient survival. The incidence of positive FCXM was 33% (16 of 48) and 13% (six of 46) by CDCXM. The median time of acute rejection was 29 d after transplantation in FCXM positive group (range 13-101 d) and 22 d in FCXM negative group (range 7-157 d, NS). Rejection rate was similar in 16 pre-transplant FCXM positive patients (eight of 16, 50%) compared with six pre-transplant CDCXM positive patients (three of six, 50%; NS). Recipients having graft rejection tended to be more often pre-transplant FCXM positive (eight of 21, 38%) than CDCXM positive (three of 21, 14%), but the difference was not significant (p > 0.1). No difference was found in the positive predictive value in relation to acute rejection between positive FCXM and CDCXM (69% vs. 50%; NS). Furthermore there was no correlation between post-transplant positive FCXM and acute rejection. No difference was found between pre-transplant T cell IgG FCXM positive and negative recipients in relation to graft or patient survival. Our findings are supportive for little risk associated with preformed donor-specific antibodies in liver transplantation.

  5. Minor antigen graft-versus-host reactions revealed in irradiated spleen and popliteal lymph node assays

    SciTech Connect

    Claman, H.N.; Jaffee, B.D.

    1984-10-01

    The graft-versus-hot (GVH) reaction across minor (non-H-2) histocompatibility barriers was studied in mice, in vivo. To increase GVH potential and to mimic clinical bone marrow transplantation protocols, we modified the popliteal lymph node (PLN) and the splenomegaly assays by irradiating the recipients before they received allogeneic lymphoid cell suspensions. In several combinations across major (H-2), minor (non-H-2) and multiple minor (non-H-2 plus minor lymphocyte stimulation) barriers, increased recipient organ weight (a measure of GVH activity) was seen with irradiated F1 recipients of parental cells. The irradiated splenomegaly (x-splenomegaly) assay was more sensitive than the (x-PLN) assay, but both correlated with in vivo GVH experiments of the P----F1 variety. The x-splenomegaly test indicated histoincompatibility in a system (B10.D2----BALB/c) in which the primary in vitro mixed leukocyte reactions is nonreactive, but in which systemic GVH can be induced. The x-splenomegaly test should be useful in analyzing complex reactions involving minor histocompatibility antigens in vivo.

  6. Localized surface grafting reactions on carbon nanofibers induced by gamma and e-beam irradiation

    NASA Astrophysics Data System (ADS)

    Evora, M. C.; Araujo, J. R.; Ferreira, E. H. M.; Strohmeier, B. R.; Silva, L. G. A.; Achete, C. A.

    2015-04-01

    Electron beam and gamma-ray irradiation have potential application to modify the carbon fiber nanostructures in order to produce useful defects in the graphitic structure and create reactive sites. In this study, the methodology to functionalize carbon nanofiber (CNF), via a radiation process and using acrylic acid as a source of oxygen functional groups, was investigated. The samples were submitted to a direct grafting radiation process with electron beam and gamma-ray source. Several parameters were changed such as: acrylic acid concentration, radiation dose and percentage of inhibitor necessary to achieve functionalization, with higher percentage of oxygen functional groups on CNF surface, and better dispersion. The better results achieved were when mixing CNF in a solution of acrylic acid with 6% of inhibitor (FeSO4·7H2O) and irradiated at 100 kGy. The samples were characterized by X-ray photoelectron spectroscopy and the surface composition (atomic%) showed a significant increase of oxygen content for the samples after irradiation. Also, the dispersion of the functionalized CNF in water was stable during months which may be a good indication that the functionalization process of CNF via ionizing radiation was successful.

  7. Preparation of starch-poly-glutamic acid graft copolymers by microwave irradiation and the characterization of their properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of waxy maize starch and poly-y-glutamic acid (PGA) were produced in an aqueous solution using microwave irradiation. The microwave reaction conditions were optimized with regard to temperature and pH. The temperature of 180 deg C and pH 7.0 were the best reaction conditions resulti...

  8. Preparation of starch-poly-glutamic acid graft copolymers by microwave irradiation and the characterization of their properties.

    PubMed

    Xu, Jingyuan; Krietemeyer, Elizabeth F; Finkenstadt, Victoria L; Solaiman, Daniel; Ashby, Richard D; Garcia, Rafael A

    2016-04-20

    Graft copolymers of waxy maize starch and poly-γ-glutamic acid (PGA) were produced in an aqueous solution using microwave irradiation. The microwave reaction conditions were optimized with regard to temperature and pH. The temperature of 180°C and pH7.0 were the best reaction conditions resulting in a PGA graft of 0.45% based on nitrogen analysis. The average graft content and graft efficiency for the starch-PGA graft copolymer prepared at 180°C and pH7.0 were 4.20% and 2.73%, respectively. The starch-PGA graft copolymer produced at 180°C and pH7.0 could absorb more than 20 times its own weight amount of water and form a gel. The preliminary rheology study revealed that the starch-PGA graft copolymer gel exhibited viscoelastic solid behavior while the control sample of waxy starch showed viscoelastic liquid behavior. PMID:26876849

  9. Cranial grafting of stem cell-derived microvesicles improves cognition and reduces neuropathology in the irradiated brain.

    PubMed

    Baulch, Janet E; Acharya, Munjal M; Allen, Barrett D; Ru, Ning; Chmielewski, Nicole N; Martirosian, Vahan; Giedzinski, Erich; Syage, Amber; Park, Audrey L; Benke, Sarah N; Parihar, Vipan K; Limoli, Charles L

    2016-04-26

    Cancer survivors face a variety of challenges as they cope with disease recurrence and a myriad of normal tissue complications brought on by radio- and chemotherapeutic treatment regimens. For patients subjected to cranial irradiation for the control of CNS malignancy, progressive and debilitating cognitive dysfunction remains a pressing unmet medical need. Although this problem has been recognized for decades, few if any satisfactory long-term solutions exist to resolve this serious unintended side effect of radiotherapy. Past work from our laboratory has demonstrated the neurocognitive benefits of human neural stem cell (hNSC) grafting in the irradiated brain, where intrahippocampal transplantation of hNSC ameliorated radiation-induced cognitive deficits. Using a similar strategy, we now provide, to our knowledge, the first evidence that cranial grafting of microvesicles secreted from hNSC affords similar neuroprotective phenotypes after head-only irradiation. Cortical- and hippocampal-based deficits found 1 mo after irradiation were completely resolved in animals cranially grafted with microvesicles. Microvesicle treatment was found to attenuate neuroinflammation and preserve host neuronal morphology in distinct regions of the brain. These data suggest that the neuroprotective properties of microvesicles act through a trophic support mechanism that reduces inflammation and preserves the structural integrity of the irradiated microenvironment. PMID:27044087

  10. Cranial grafting of stem cell-derived microvesicles improves cognition and reduces neuropathology in the irradiated brain

    PubMed Central

    Baulch, Janet E.; Acharya, Munjal M.; Allen, Barrett D.; Ru, Ning; Chmielewski, Nicole N.; Martirosian, Vahan; Giedzinski, Erich; Syage, Amber; Park, Audrey L.; Benke, Sarah N.; Parihar, Vipan K.; Limoli, Charles L.

    2016-01-01

    Cancer survivors face a variety of challenges as they cope with disease recurrence and a myriad of normal tissue complications brought on by radio- and chemotherapeutic treatment regimens. For patients subjected to cranial irradiation for the control of CNS malignancy, progressive and debilitating cognitive dysfunction remains a pressing unmet medical need. Although this problem has been recognized for decades, few if any satisfactory long-term solutions exist to resolve this serious unintended side effect of radiotherapy. Past work from our laboratory has demonstrated the neurocognitive benefits of human neural stem cell (hNSC) grafting in the irradiated brain, where intrahippocampal transplantation of hNSC ameliorated radiation-induced cognitive deficits. Using a similar strategy, we now provide, to our knowledge, the first evidence that cranial grafting of microvesicles secreted from hNSC affords similar neuroprotective phenotypes after head-only irradiation. Cortical- and hippocampal-based deficits found 1 mo after irradiation were completely resolved in animals cranially grafted with microvesicles. Microvesicle treatment was found to attenuate neuroinflammation and preserve host neuronal morphology in distinct regions of the brain. These data suggest that the neuroprotective properties of microvesicles act through a trophic support mechanism that reduces inflammation and preserves the structural integrity of the irradiated microenvironment. PMID:27044087

  11. Immunosuppressive Total Lymphoid Irradiation-Based Reconditioning Regimens Enable Engraftment After Graft Rejection or Graft Failure in Patients Treated With Allogeneic Hematopoietic Stem Cell Transplantation

    SciTech Connect

    Heinzelmann, Frank; Lang, Peter J.; Ottinger, Hellmut; Faul, Christoph; Bethge, Wolfgang; Handgretinger, Rupert; Bamberg, Michael; Belka, Claus

    2008-02-01

    Purpose: To retrospectively evaluate the efficacy of total lymphoid irradiation (TLI)-based reconditioning regimens in patients with graft failure or graft rejection after allogeneic hematopoietic stem cell transplantation. Methods and Materials: The results of 14 patients (7 adults and 7 children) with a variety of hematologic malignant diseases treated with a TLI-based reconditioning regimen with 7-Gy single-dose application plus anti-T-lymphocyte antibody OKT3 (n = 11) and/or antithymocyte globulin (n = 7)/fludarabine (n = 9), followed by an infusion of peripheral blood stem cells (n = 13) or bone marrow stem cells (n = 1) from related or unrelated donors, were retrospectively analyzed. Results: Of the 14 recipients, the data from 11 were evaluable for engraftment after TLI-based reconditioning because 3 adults died early (at Day 2, 5, and 15) after the second transplantation of infectious complications. Engraftment in 4 adults was seen after a median of 12 days (range, 10-18) and occurred after a median of 10 days (range, 9-32) in the 7 children. TLI-based reconditioning was well-tolerated with no severe toxicity. The median overall survival and disease-free survival for the whole cohort was 140 days (range, 5-1,268). After a median follow-up of 681 days, the disease-free survival and overall survival rate was 85.7% and 85.7%, respectively, in the children. Despite engraftment in the 4 remaining adults, 1 died of fatal graft-vs.-host disease, 1 of infectious complications, 1 of disease relapse, and 1 of acute respiratory distress syndrome. Conclusions: In patients with graft failure or graft rejection after allogeneic hematopoietic stem cell transplantation, TLI-based reconditioning regimens allow sustained engraftment, paralleled by a favorable toxicity profile, potentially leading to long-term survival.

  12. Mutual irradiation grafting on indigenous aramid fiber-3 in diethanolamine and epichlorohydrin and its effect on interfacially reinforced epoxy composite

    NASA Astrophysics Data System (ADS)

    Xing, Lixin; Liu, Li; Xie, Fei; Huang, Yudong

    2016-07-01

    The surface of indigenous aramid fiber-3 (IAF3) was decorated via mutual irradiation grafting process in diethanolamine (DEA) and epichlorohydrin (ECH), respectively, with the assist of high energy gamma rays. This modification method with great permeability produced the homogeneous and ameliorative AF3 surfaces, which were observed by the scanning electron microscopy (SEM) and atom forced microscopy (AFM). Enhanced surface free energy and reduced contact angles of irradiated AF3 verified the fabulous effectiveness of mutual irradiation without seriously injured tensile strength. The composites based on epoxy resin (ER) polymer as the matrix and irradiated IAF3 grafted DEA and ECH as the reinforcement. By capitalizing on the irradiated IAF3 which has higher wettability and adsorption on resin, the irradiated IAF3-ECH/ER composites exhibit admirable interfacial mechanical performance as compared to the pristine IAF3 contained composites. The interfacial shear strength (IFSS), interlaminar shear strength (ILSS) and flexural strength of composites were remarkable improved to 86.5, 60.13 and 511 MPa respectively, from the pristine IAF3/ER composite with IFSS of 65.9 MPa, ILSS of 48.1 MPa, and flexural strength of 479 MPa.

  13. Immunological and clinical observations in diabetic kidney graft recipients pretreated with total-lymphoid irradiation

    SciTech Connect

    Waer, M.; Vanrenterghem, Y.; Roels, L.; Ang, K.K.; Bouillon, R.; Lerut, T.; Gruwez, J.; van der Schueren, E.; Vandeputte, M.; Michielsen, P.

    1987-03-01

    In a feasibility study, twenty patients with end-stage diabetic nephropathy were treated with fractionated total-lymphoid irradiation (TLI, mean dose 25 Gy), before transplantation of a first cadaveric kidney. During radiotherapy, only one patient had a serious side effect (bone marrow depression). After transplantation four patients died (one of a myocardial infarction, one of ketoacidosis, and two of infections occurring during treatment of rejection crises). One graft was lost because of chronic rejection. The other 15 patients have a functioning graft (mean follow-up 24 months) and receive low-dose prednisone alone (less than 10 mg/day, n = 11) or in conjunction with cyclosporine (n = 4) as maintenance immunosuppressive therapy. A favorable clinical outcome after TLI (no, or only one, steroid-sensitive rejection crisis) was significantly correlated with a high pre-TLI helper/suppressor lymphocyte ratio, a short interval between TLI and the time of transplantation, and the occurrence of functional suppressor cells early after TLI. The most striking immunological changes provoked by TLI consisted of a long-term depression of the mixed lymphocyte reaction and of the phytohemagglutinin, and Concanavalin A or pokeweed-mitogen-induced blastogenesis. A rapid and complete recovery of the natural killer cell activity was observed after TLI. A permanent inversion of the OKT4+ (T helper/inducer) over OKT8+ (T suppressor/cytotoxic) lymphocyte ratio was provoked by a decrease of the OTK4+ subpopulation, together with a supranormal recovery of the OKT8+ lymphocytes. A majority of the latter lymphocytes did also express the Leu 7 and the Leu 15 phenotype.

  14. ESCA characterization of heparin-like fluoropolymers obtained by functionalization after grafting induced by swift heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Dapoz, Sylvie; Betz, Natacha; Guittet, Marie-Jo; Le Moël, Alain

    1995-11-01

    Poly(vinylidene fluoride) (PVDF) and the poly(hexafluoropropylene-vinylidene fluoride) (Viton) films are modified in order to produce heparin-like materials. This transformation is carried out on three steps: swift heavy ion irradiation (performed at the GANIL, Caen, France) of the polymer substrates, polystyrene (PS) grafting, functionalization of the PS. X-ray photoelectron spectroscopy is used to analyze the modification of the surface chemical composition at the several steps.

  15. Preparation of metal adsorbent from poly(methyl acrylate)-grafted-cassava starch via gamma irradiation

    NASA Astrophysics Data System (ADS)

    Suwanmala, Phiriyatorn; Hemvichian, Kasinee; Hoshina, Hiroyuki; Srinuttrakul, Wannee; Seko, Noriaki

    2012-08-01

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, % Dg=191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum condition. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15 and 1.6 mmol/g-adsorbent for Cd2+, Al3+, UO22+, V5+ and Pb2+, respectively, in the batch mode adsorption.

  16. Removal of reactive dyes from textile wastewater by immobilized chitosan upon grafted Jute fibers with acrylic acid by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Hassan, Mahmoud S.

    2015-10-01

    Jute fibers were grafted with acrylic acid by gamma irradiation technique. Chitosan was immobilized upon the grafted Jute fibers to be used as an adsorbent for waste reactive dye. The treated Jute fibers were characterized by using of Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of Jute treatment on its thermal stability by using thermogravimetric analysis (TGA) and its mechanical properties were investigated. The adsorption isotherm and the different factors affecting the dye adsorption such as pH and contact time were also studied. It was found that the dye adsorption was enhanced in the low pH range and increased with increasing of the contact time, regardless of temperature change.

  17. Grafting of neural stem and progenitor cells to the hippocampus of young, irradiated mice causes gliosis and disrupts the granule cell layer

    PubMed Central

    Sato, Y; Shinjyo, N; Sato, M; Osato, K; Zhu, C; Pekna, M; Kuhn, H G; Blomgren, K

    2013-01-01

    Ionizing radiation persistently reduces the pool of neural stem and progenitor cells (NSPCs) in the dentate gyrus (DG) of the hippocampus, which may explain some of the learning deficits observed in patients treated with radiotherapy, particularly pediatric patients. A single dose of 8 Gy irradiation (IR) was administered to the brains of postnatal day 14 (P14) C57BL/6 mice and 1.0 × 105 bromodeoxyuridine-labeled, syngeneic NSPCs were injected into the hippocampus 1 day, 1 week or 6 weeks after IR. Cell survival and phenotype were evaluated 5 weeks after grafting. When grafted 1 day post-IR, survival and neuronal differentiation of the transplanted NSPCs were lower in irradiated brains, whereas the survival and cell fate of grafted cells were not significantly different between irradiated and control brains when transplantation was performed 1 or 6 weeks after IR. A young recipient brain favored neuronal development of grafted cells, whereas the older recipient brains displayed an increasing number of cells developing into astrocytes or unidentified cells. Injection of NSPCs, but not vehicle, induced astrogliosis and reduced thickness of the dorsal blade of the GCL after 5 months. In summary, we demonstrate that age and interval between IR and grafting can affect survival and differentiation of grafted NSPCs. The observed long-term gliosis and degeneration warrant caution in the context of NSPC grafting for therapeutical purposes. PMID:23598403

  18. Whole-body UVB irradiation during allogeneic hematopoietic cell transplantation is safe and decreases acute graft-versus-host disease.

    PubMed

    Kreutz, Marina; Karrer, Sigrid; Hoffmann, Petra; Gottfried, Eva; Szeimies, Rolf-Markus; Hahn, Joachim; Edinger, Matthias; Landthaler, Michael; Andreesen, Reinhard; Merad, Miriam; Holler, Ernst

    2012-01-01

    Depletion of host Langerhans cells (LCs) prevents cutaneous graft-versus-host disease (GvHD) in mice. We analyzed whether UVB irradiation is tolerated during the course of human allogeneic hematopoietic cell transplantation and whether depletion of LCs by broadband UVB could improve GvHD outcome. A total of 17 patients received six whole-body UVB irradiations with 75% of the individually determined minimal erythemal dose after conditioning with a reduced intensity protocol. LCs, dermal dendritic cells (DCs), and macrophages were analyzed before and after UVB irradiation by immunohistochemical analysis. Circulating blood cells and serum factors were analyzed in parallel. In striking contrast to previous data, our irradiation protocol was well tolerated in all patients. UVB treatment decreased the number of LCs and also affected dermal DCs. UVB-treated patients also had significantly higher 25-hydroxyvitamin D3 serum levels and higher numbers of circulating CD4+ FoxP3+ regulatory T cells. Strikingly, nine out of nine patients with complete LC depletion (<1 LC per field) developed only grade I GvHD or no GvHD up to day 100. Our results strongly suggest that prophylactic UVB irradiation post transplant is safe and should be further explored as a clinical strategy to prevent acute (skin) GvHD.

  19. A circulating antibody panel for pretransplant prediction of FSGS recurrence after kidney transplantation

    PubMed Central

    Delville, Marianne; Sigdel, Tara K.; Wei, Changli; Li, Jing; Hsieh, Szu-Chuan; Fornoni, Alessia; Burke, George W.; Bruneval, Patrick; Naesens, Maarten; Jackson, Annette; Alachkar, Nada; Canaud, Guillaume; Legendre, Christophe; Anglicheau, Dany; Reiser, Jochen; Sarwal, Minnie M.

    2015-01-01

    Recurrence of focal segmental glomerulosclerosis (rFSGS) after kidney transplantation is a cause of accelerated graft loss. To evaluate pathogenic antibodies (Abs) in rFSGS, we processed 141 serum samples from 64 patients with and without primary rFSGS and 34 non-FSGS control patients transplanted at four hospitals. We screened about 9000 antigens in pretransplant sera and selected 10 Abs targeting glomerular antigens for enzyme-linked immunosorbent assay (ELISA) validation. A panel of seven Abs (CD40, PTPRO, CGB5, FAS, P2RY11, SNRPB2, and APOL2) could predict posttransplant FSGS recurrence with 92% accuracy. Pretransplant elevation of anti-CD40 Ab alone had the best correlation (78% accuracy) with rFSGS risk after transplantation. Epitope mapping of CD40 with customized peptide arrays and rFSGS sera demonstrated altered immunogenicity of the extracellular CD40 domain in rFSGS. Immunohistochemistry of CD40 demonstrated a differential expression in FSGS compared to non-FSGS controls. Anti-CD40 Abs purified from rFSGS patients were particularly pathogenic in human podocyte cultures. Injection of anti-CD40/rFSGS Ab enhanced suPAR (soluble urokinase receptor)–mediated proteinuria in wild-type mice, yet no sensitizing effect was noted in mice deficient in CD40 or in wild-type mice that received blocking Ab to CD40. In conclusion, a panel of seven Abs can help identify primary FSGS patients at high risk of recurrence before transplantation. Intrarenal CD40 (and possibly other specific glomerular antigens) is an important contributor to FSGS disease pathogenesis. Human trials of anti-CD40 therapies are warranted to evaluate their efficacy for preventing rFSGS and improving graft survival. PMID:25273097

  20. Preparation and characterization of poly(methyl methacrylate) and poly(maleic anhydride-co-diallyl phthalate) grafted carbon black through γ-ray irradiation

    NASA Astrophysics Data System (ADS)

    Bo, Yang; Cui, Jiayang; Cai, Yangben; Xu, Shiai

    2016-02-01

    In this study, the grafting polymerization of methyl methacrylate (MMA) monomer and maleic anhydride/diallyl phthalate (MAH/DAP) co-monomer onto the surface of carbon black (CB) were carried out at room temperature and normal pressure by γ-ray irradiation. The surface chemistry of grafted CBs were characterized by infrared spectroscopy (IR), thermo-gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The results show that there are some remanent polymers on the surface of modified CBs after extract for 48 h, indicating that poly(methyl methacrylate) (PMMA) and poly(MAH-co-DAP) have been successfully grafted onto the surface of CB without using initiator due to the high energy of γ-ray irradiation. Dynamic light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) reveal that the grafted CBs have smaller average aggregate size and better dispersibility than that of CB in absolute ethanol. In addition, it was found that the amount of oxygen groups and the irradiation doses/dose rates have little effect on the grafting degree of CB.

  1. Preparation and characterization of mono-sheet bipolar membranes by pre-irradiation grafting method for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Guan, Yingjie; Fang, Jun; Fu, Tao; Zhou, Huili; Wang, Xin; Deng, Zixiang; Zhao, Jinbao

    2016-09-01

    A new method for the preparation of the mono-sheet bipolar membrane applied to fuel cells was developed based on the pre-irradiation grafting technology. A series of bipolar membranes were successfully prepared by simultaneously grafting of styrene onto one side of the poly(ethylene-co-tetrafluoroethylene) base film and 1-vinylimidazole onto the opposite side, followed by the sulfonation and alkylation, respectively. The chemical structures and microstructures of the prepared membranes were investigated by ATR-FTIR and SEM-EDS. The TGA measurements demonstrated the prepared bipolar membranes have reasonable thermal stability. The ion exchange capacity, water uptake and ionic conductivity of the membranes were also characterized. The H2/O2 single fuel cells using these membranes were evaluated and revealed a maximum power density of 107 mW cm-2 at 35 °C with unhumidified hydrogen and oxygen. The preliminary performances suggested the great prospect of these membranes in application of bipolar membrane fuel cells.

  2. Best practices in the pediatric pretransplant psychosocial evaluation.

    PubMed

    Lefkowitz, Debra S; Fitzgerald, Christopher J; Zelikovsky, Nataliya; Barlow, Katherine; Wray, Jo

    2014-06-01

    Assessment of psychosocial functioning is an often-included component of the pretransplant evaluation process. This study reviews several domains of assessment that have been related to post-transplant outcomes across solid organ transplant populations. These include evaluation of patient and family past adherence, knowledge about the transplantation process, and their neurocognitive, psychological, and family functioning. To date, few comprehensive pretransplant evaluation measures have been standardized for use with children; however, several assessment measures used to evaluate the aforementioned domains are reviewed throughout the study. Additionally, this article discusses some developmental, illness-specific, and cultural considerations in conducting the psychosocial evaluation. We also discuss ethical issues specific to the pediatric psychosocial evaluation. Recommendations are advanced to promote a comprehensive evaluation that identifies family strengths and risk factors as they begin the transplant journey. PMID:24802341

  3. Nano-composite of poly(L-lactide) and halloysite nanotubes surface-grafted with L-lactide oligomer under microwave irradiation.

    PubMed

    Luo, Bing-Hong; Hsu, Chung-En; Li, Jian-Hua; Zhao, Liang-Feng; Liu, Ming-Xian; Wang, Xiao-Ying; Zhou, Chang-Ren

    2013-04-01

    In order to improve the bonding between halloysite nanotubes (HNTs) and poly(L-lactide) (PLLA), and hence to increase the mechanical properties of HNTs/PLLA nano-composite, HNTs were surface-grafted with PLLA under microwave irradiation and then blended with PLLA matrix. The optimal conditions for grafting polymerization are: irradiation time of 30 min, microwave power of 30 W and reaction temperature of 130 degrees C. The structure and properties of the surface-grafted HNTs (g-HNTs) were characterized by Fourier transformation infrared (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and dynamic light scattering (DLS). Nano-composites of g-HNTs/PLLA and non-grafted HNTs/PLLA were subsequently evaluated in terms of crystallinity, dispersion, interfacial interaction, mechanical performance and cytocompatibility by polarized optical microscopy (POM), field scanning electron microscope (FESM), tensile testing and cell culture experiment. Results show that the grafted PLLA chains on the surfaces of HNTs, as inter-tying molecules, played an important role in improving the adhesive strength between the nanotubes and the polymer matrix. The enhanced interaction among g-HNTs and PLLA matrix resulted in a better tensile strength and modulus compared to the pristine PLLA and HNTs/PLLA. Cell culture results indicated that g-HNTs promoted both adhesion and proliferation of M3T3 fibroblasts on the g-HNTs/PLLA composite film.

  4. Histology of porcine nasal cartilage grafts following Nd:YAG (1320 nm) laser-mediated reshaping: effects of sequential irradiation

    NASA Astrophysics Data System (ADS)

    Kim, Hong K.; Wong, Brian J.; Benton, Hilary P.; Liaw, Lih-Huei L.; Nelson, J. Stuart; Milner, Thomas E.

    2001-07-01

    Mechanically deformed morphologic cartilage grafts undergo temperature dependent stress relaxation during sustained laser irradiation resulting in stable shape changes. In this study, the porcine nasal septal cartilage specimens were evaluated histologically following laser mediated reshaping using H&E. Cartilage specimens were irradiated with light emitted from a Nd:YAG laser (25 W/cm2, 1 = 1.32 mm) while recording simultaneously radiometric surface temperature, internal stress, and backscattered light intensity from a probe laser. Each specimen received one, two, or three sequential laser exposures. The duration of each exposure was determined from real-time measurements of characteristic changes in backscattered light intensity that correlate with accelerated stress relaxation. A five minute time interval between each laser exposures allowed the cartilage specimen to return to thermal equilibrium. Specimens were then fixed in formalin, serially dehydrated in ethanol, embedded in paraffin, and sectioned with a microtome for histologic examination using light microscopy. Large variation in native tissue histology was observed among individual tissue samples, and vascular were identified in several specimens. Large lacunae with shrunken chondrocytes were identified along with cells with pyknotic nuclei, although these histologic observations did not correlate with the degree of laser exposure. These observations are discussed.

  5. A radio-resistant perforin-expressing lymphoid population controls allogeneic T cell engraftment, activation, and onset of graft-versus-host disease in mice.

    PubMed

    Davis, Joanne E; Harvey, Michael; Gherardin, Nicholas A; Koldej, Rachel; Huntington, Nicholas; Neeson, Paul; Trapani, Joseph A; Ritchie, David S

    2015-02-01

    Immunosuppressive pretransplantation conditioning is essential for donor cell engraftment in allogeneic bone marrow transplantation (BMT). The role of residual postconditioning recipient immunity in determining engraftment is poorly understood. We examined the role of recipient perforin in the kinetics of donor cell engraftment. MHC-mismatched BMT mouse models demonstrated that both the rate and proportion of donor lymphoid cell engraftment and expansion of effector memory donor T cells in both spleen and BM were significantly increased within 5 to 7 days post-BMT in perforin-deficient (pfn(-/-)) recipients, compared with wild-type. In wild-type recipients, depletion of natural killer (NK) cells before BMT enhanced donor lymphoid cell engraftment to that seen in pfn(-/-) recipients. This demonstrated that a perforin-dependent, NK-mediated, host-versus-graft (HVG) effect limits the rate of donor engraftment and T cell activation. Radiation-resistant natural killer T (NKT) cells survived in the BM of lethally irradiated mice and may drive NK cell activation, resulting in the HVG effect. Furthermore, reduced pretransplant irradiation doses in pfn(-/-) recipients permitted long-term donor lymphoid cell engraftment. These findings suggest that suppression of perforin activity or selective depletion of recipient NK cells before BMT could be used to improve donor stem cell engraftment, in turn allowing for the reduction of pretransplant conditioning.

  6. The Use Of Laser Irradiation To Stimulate Adipose Derived Stem Cell Proliferation And Differentiation For Use In Autologous Grafts

    NASA Astrophysics Data System (ADS)

    Abrahamse, Heidi

    2009-09-01

    fluences on ADSC viability and proliferation. This paper reviews the development of MSCs as potential therapeutic interventions such as autologous grafts as well as the contribution of low intensity laser irradiation on the maintenance of these cells.

  7. Gamma-ray co-irradiation induced graft polymerization of NVP and SSS onto polypropylene non-woven fabric and its blood compatibility

    NASA Astrophysics Data System (ADS)

    Li, Rong; Wang, Hengdong; Wang, Wenfeng; Ye, Yin

    2013-10-01

    Sodium styrenesulfonate was grafted onto PPNWF via γ-ray co-irradiation method with the existence of N-vinyl-2-pyrrolidone. The effect of absorbed dose, dose rate and concentration of binary monomer on the degree of grafting was investigated. The surface chemical change was characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The wettability was characterized through the measurement of adsorption percentage of water and phosphate buffer solution (PBS). The result demonstrated that the grafted poly(NVP-co-SSS) chains can improve the hydrophilicity of PPNWF. Furthermore, the modified PPNWF has good blood compatibility, such as low hemolysis rate, low platelet adhesion and effectively extending the blood coagulation times. Consequently, hydrophilicity and hemocompatibility of PPNWF were greatly enhanced by the immobilization of poly(NVP-co-SSS) chains.

  8. Preparation, properties and biological application of pH-sensitive poly(ethylene oxide) (PEO) hydrogels grafted with acrylic acid(AAc) using gamma-ray irradiation

    NASA Astrophysics Data System (ADS)

    Nho, Young Chang; Mook Lim, Youn; Moo Lee, Young

    2004-09-01

    pH-sensitive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing it in the small intestine. In this study, hydrogels based on poly(ethylene oxide) (PEO) networks grafted with acrylic acid (AAc) were prepared via a two-step process. PEO hydrogels were prepared by γ-ray irradiation, and then grafting by AAc monomer onto the PEO hydrogels with the subsequent irradiation (radiation dose: 5-20 kGy, dose rate: 2.15 kGy/h). These grafted hydrogels showed a pH-sensitive swelling behavior. The grafted hydrogels were used as a carrier for the drug delivery systems for the controlled release of insulin. The in vitro drug release behaviors of these hydrogels were examined by quantification analysis with a UV/VIS spectrophotometer. Insulin was loaded into freeze-dried hydrogels (7 mm×3 mm×2.5 mm) and administrated orally to healthy and diabetic Wistar rats. The oral administration of insulin-loaded hydrogels to Wistar rats decreased the blood glucose levels obviously for at least 4 h due to the absorption of insulin in the gastrointestinal tract.

  9. Failure of donor lymphocyte infusion to prevent graft rejection in dogs given DLA-identical marrow after 1 Gy of total body irradiation.

    PubMed

    Baron, Frédéric; Sandmaier, Brenda M; Zellmer, Eustacia; Sorror, Mohamed; Storer, Barry; Storb, Rainer

    2006-08-01

    We investigated in a preclinical canine model of hematopoietic cell transplantation (HCT) whether preemptive donor lymphocyte infusion (DLI) given 1 month after HCT could prevent late graft rejection that was the rule in historical dogs given suboptimal conditioning with 1 Gy of total body irradiation (TBI) before and immunosuppression with cyclosporine (CSP) and either mycophenolate mofetil (MMF; n = 6) or rapamycin (n = 5) after dog leukocyte antigen (DLA)-identical marrow transplantation. Nine dogs given DLA-identical marrow after 1 Gy of TBI followed by postgrafting MMF and CSP were studied. A single DLI was given 28-36 days after HCT, either with (n = 5) or without (n = 4) preceding treatment with the immunosuppressive drug pentostatin. Two of the 4 dogs given DLI only maintained stable mixed donor-host chimera beyond 30 weeks after HCT, whereas 2 rejected their grafts, on weeks 10 and 15 after HCT. One of the 5 dogs given pentostatin before DLI maintained a stable mixed donor-host chimera beyond 30 weeks, whereas 4 rejected their grafts, at weeks 8, 12, 12, and 16 after HCT. The 30-week probability of stable mixed chimerism was 33% among dogs given DLI, versus 0% among 11 historical dogs (P = .003). In conclusion, DLI was only moderately effective in preventing graft rejection in this model. Additional immunosuppression with pentostatin did not improve that outcome. The model might be useful in developing potential strategies aimed at preventing graft rejection in patients with low donor chimerism levels. PMID:16864051

  10. Effects of marrow grafting on preleukemia cells and thymic nurse cells in C57BL/Ka mice after a leukemogenic split-dose irradiation

    SciTech Connect

    Defresne, M.P.; Greimers, R.; Lenaerts, P.; Boniver, J.

    1986-11-01

    A split-dose regimen of whole-body irradiation (4 X 175 rad at weekly intervals) induced thymic lymphomas in C57BL/Ka mice after a latent period of 3-9 months. Meanwhile, preleukemia cells arose in the thymus and bone marrow and persisted until the onset of lymphomas. Simultaneously, thymic lymphopoiesis was impaired; thymocyte numbers were subnormal and thymic nurse cells disappeared in a progressive but irreversible fashion. The depletion of these lymphoepithelial complexes, which are normally involved in the early steps of thymic lymphopoiesis, was related to altered prothymocyte activity in bone marrow and to damaged thymic microenvironment, perhaps as a consequence of the presence of preleukemia cells. The grafting of normal bone marrow cells after irradiation prevented the development of lymphomas. However, marrow reconstitution did not inhibit the induction of preleukemia cells. They disappeared from the thymus during the second part of the latent period. At the same time, thymic lymphopoiesis was restored; thymocytes and nurse cell numbers returned to normal as a consequence of the proliferation of grafted marrow-derived cells within the thymus. The results thus demonstrated an intimate relationship between preleukemia cells and an alteration of thymic lymphopoiesis, which particularly involved the nurse cell microenvironment. Some preleukemia cells in marrow-reconstituted, irradiated mice derived from the unirradiated marrow inoculate. Thus these cells acquired neoplastic potential through a factor present in the irradiated tissues. The nature of this indirect mechanism was briefly discussed.

  11. Long-term survival after renal transplantation: the influence of pretransplant bilateral nephrectomy.

    PubMed

    Douglas, James F; Craig, W J Colin

    2010-01-01

    The long-term survival of first successful renal transplants, along with overall patient survival, was studied retrospectively in 309 recipients at Belfast City Hospital between 1968 and 1986, of whom 155 had undergone prior bilateral nephrectomy (BN) and 154 had not (non-BN). The groups were comparable as regards mean age, gender, primary diagnoses, clinical status, pre-existing hypertension and pre-transplant dialysis and transfusion. There were 34 organs (BN 14, non-BN 20) from living related donors. Donor ages were comparable, as were histocompatibility findings. Recipients more than 60, with diabetic nephropathy, or with other co-morbidity were excluded. All recipients took azathioprine and low-dose steroid as maintenance antirejection, fewer than 3% switching to cyclosporine or other drugs during first graft survival. Mean BN graft survival was 15.9 years (95% CI 14.1-17.7) compared to 12.9 for non-BN (95% CI 11.3-14.5; p < 0.01). Mean BN patient survival was 19.4 years (95% CI 17.6-21.2) and non-BN was 14.9 years (95% CI 13.2-16.6; p < 0.01). Cumulative BN graft survival was 76.8% at 5 years, 61.6% at 10 years, and 37.4% at 20 years, compared to 67.1%, 53.5% and 27.0% for non-BN (p < 0.01). Overall BN patient survival was 84.5% at 5 years, 74.2% at 10 years and 51.6% at 20 years, with non-BN equivalents of 72.3%, 49.0% and 24.5%, respectively (p < 0.01). Long-term BN survivors also had less hypertension than non-BN (22.8% v 54.8% at 20 years; p < 0.05) which may be relevant to their better survival. Overall (BN plus non-BN) median graft (14.4 years) and patient (17.6 years) survival are testimony to the continuing long-term success of the low-dose steroid regime followed in Belfast from 1968 to 1986.

  12. The role of pattern-recognition receptors in graft-versus-host disease and graft-versus-leukemia after allogeneic stem cell transplantation.

    PubMed

    Heidegger, Simon; van den Brink, Marcel R M; Haas, Tobias; Poeck, Hendrik

    2014-01-01

    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only treatment with curative potential for certain aggressive hematopoietic malignancies. Its success is limited by acute graft-versus-host disease (GVHD), a life-threatening complication that occurs when allo-reactive donor T cells attack recipient organs. There is growing evidence that microbes and innate pattern-recognition receptors (PRRs) such as toll-like receptors (TLR) and nod-like receptors (NLR) are critically involved in the pathogenesis of acute GVHD. Currently, a widely accepted model postulates that intensive chemotherapy and/or total-body irradiation during pre-transplant conditioning results in tissue damage and a loss of epithelial barrier function. Subsequent translocation of bacterial components as well as release of endogenous danger molecules stimulate PRRs of host antigen-presenting cells to trigger the production of pro-inflammatory cytokines (cytokine storm) that modulate T cell allo-reactivity against host tissues, but eventually also the beneficial graft-versus-leukemia (GVL) effect. Given the limitations of existing immunosuppressive therapies, a better understanding of the molecular mechanisms that govern GVHD versus GVL is urgently needed. This may ultimately allow to design modulators, which protect from GvHD but preserve donor T-cell attack on hematologic malignancies. Here, we will briefly summarize current knowledge about the role of innate immunity in the pathogenesis of GVHD and GVL following allo-HSCT.

  13. Crosslinked grafted PVC obtained by direct radiation grafting

    NASA Astrophysics Data System (ADS)

    Hegazy, El-Sayed A.; Dessouki, Ahmed M.; El-Dessouky, Maher M.; El-Sawy, Naeem M.

    Direct radition-induced grafting of 4-vinylpyridine onto both pure and plasticized poly(vinyl chloride) has been studied. The effect of grafting conditions such as solvent, monomer concentration, irradiation dose, and inhibitor concentration on the grafting yield was investigated. The grafting process was enhanced by using distilled water as diluent and higher degrees of grafting were obtained as compared with other solvents used (benzene, methanol, and a mixture of methanol and water). The homopolymerization of 4-vinylpyridine was reduced to a minimum using ammonium ferrous sulfate and the suitable optimum concentration of the inhibitor was found to be 0.25 wt %. It was observed that the degrees of grafting onto plasticized PVC were higher than those onto pure one, at constant grafting conditions. The diffusibility of the monomer solution through the trunk polymers enhanced at higher monomer concentrations. The higher the monomer concentration the higher the degrees of grafting obtained. The dependence of the grafting rate on monomer concentration was found to be 0.15 and 0.4 order for the grafting onto pure and plasticized PVC films, respectively. The degree of grafting, at the higher irradiation doses, deviated from linearity and it tends to level off due to the recombination of some of the free radicals without initiating graft polymerization. Gel determination in the grafted films was investigated. The gel content in both grafted extracted pure and plasticized PVC films increased with the degree of grafting to reach a certain limiting values.

  14. Prevention of transfusion-associated graft-versus-host disease by irradiation: technical aspect of a new ferrous sulphate dosimetric system.

    PubMed

    Del Lama, Lucas Sacchini; de Góes, Evamberto Garcia; Petchevist, Paulo César Dias; Moretto, Edson Lara; Borges, José Carlos; Covas, Dimas Tadeu; de Almeida, Adelaide

    2013-01-01

    Irradiation of whole blood and blood components before transfusion is currently the only accepted method to prevent Transfusion-Associated Graft-Versus-Host-Disease (TA-GVHD). However, choosing the appropriate technique to determine the dosimetric parameters associated with blood irradiation remains an issue. We propose a dosimetric system based on the standard Fricke Xylenol Gel (FXG) dosimeter and an appropriate phantom. The modified dosimeter was previously calibrated using a (60)Co teletherapy unit and its validation was accomplished with a (137)Cs blood irradiator. An ionization chamber, standard FXG, radiochromic film and thermoluminescent dosimeters (TLDs) were used as reference dosimeters to determine the dose response and dose rate of the (60)Co unit. The dose distributions in a blood irradiator were determined with the modified FXG, the radiochromic film, and measurements by TLD dosimeters. A linear response for absorbed doses up to 54 Gy was obtained with our system. Additionally, the dose rate uncertainties carried out with gel dosimetry were lower than 5% and differences lower than 4% were noted when the absorbed dose responses were compared with ionization chamber, film and TLDs.

  15. Prevention of Transfusion-Associated Graft-versus-Host Disease by Irradiation: Technical Aspect of a New Ferrous Sulphate Dosimetric System

    PubMed Central

    Del Lama, Lucas Sacchini; de Góes, Evamberto Garcia; Petchevist, Paulo César Dias; Moretto, Edson Lara; Borges, José Carlos; Covas, Dimas Tadeu; de Almeida, Adelaide

    2013-01-01

    Irradiation of whole blood and blood components before transfusion is currently the only accepted method to prevent Transfusion-Associated Graft-Versus-Host-Disease (TA-GVHD). However, choosing the appropriate technique to determine the dosimetric parameters associated with blood irradiation remains an issue. We propose a dosimetric system based on the standard Fricke Xylenol Gel (FXG) dosimeter and an appropriate phantom. The modified dosimeter was previously calibrated using a 60Co teletherapy unit and its validation was accomplished with a 137Cs blood irradiator. An ionization chamber, standard FXG, radiochromic film and thermoluminescent dosimeters (TLDs) were used as reference dosimeters to determine the dose response and dose rate of the 60Co unit. The dose distributions in a blood irradiator were determined with the modified FXG, the radiochromic film, and measurements by TLD dosimeters. A linear response for absorbed doses up to 54 Gy was obtained with our system. Additionally, the dose rate uncertainties carried out with gel dosimetry were lower than 5% and differences lower than 4% were noted when the absorbed dose responses were compared with ionization chamber, film and TLDs. PMID:23762345

  16. Natural resistance of lethally irradiated F1 hybrid mice to parental marrow grafts is a function of H-2/Hh-restricted effectors

    SciTech Connect

    Daley, J.P.; Nakamura, I.

    1984-04-01

    The natural resistance of F1 hybrid mice against parental bone marrow grafts is thought to be mediated by natural killer (NK)-like effector cells. However, unlike the NK cell activity against a wide range of tumors and normal cells, hybrid resistance is characterized by the immunogenetic specificity controlled by a set of unique noncodominant genes denoted as Hh. Two alternative hypotheses can account for the specificity. Thus, the specificity may reflect either the Hh restriction of effectors or the Hh gene control of mechanisms regulating non-Hh-restricted effector activity. In this study, therefore, we tested the recognition specificity of putative effectors mediating hybrid resistance in lethally irradiated H-2b/d and H-2b/k F1 hybrid mice to the engraftment of parental H-2b bone marrow. As a direct means of defining the effector specificity, rejection of parental bone marrow grafts was subjected to competitive inhibition in situ by irradiated tumor cells. Of the 16 independent lines of lymphoma and other hemopoietic tumor cells tested, the ability to inhibit hybrid resistance was the exclusive property of all tumors derived from mice homozygous for the H-2Db region, regardless of whether the tumor cells were susceptible or resistant to NK cell-mediated cytotoxicity in vitro. Four cell lines heterozygous for the H-2Db were noninhibitory, including one that is susceptible to natural killing. Pretreatment of the F1 hosts with an interferon inducer augmented the resistance with no alteration in the recognition specificity of effector cells. Therefore, natural resistance to parental H-2b bone marrow grafts was mediated by effectors restricted by the H-2Db/Hh-1b gene(s), and not by the nonrestricted NK cells detectable in conventional in vitro assays.

  17. New CO2 adsorbent containing aminated poly(glycidyl methacrylate) grafted onto irradiated PE-PP nonwoven sheet

    NASA Astrophysics Data System (ADS)

    Mahmoud Nasef, Mohamed; Abbasi, Ali; Ting, T. M.

    2014-10-01

    A new CO2 adsorbent containing triethylamine (TEA) was prepared by radiation induced grafting of glycidyl methacrylate (GMA) onto polyethylene coated polypropylene (PE-PP) non-woven sheet followed by amination reaction. The degree of grafting (DOG%) was controlled by variation of monomer concentration and absorbed dose. The incorporation of aminated poly(GMA) was investigated by Fourier transform infrared (FTIR) and scanning electron microscope (SEM). The adsorbent with DOG of 350% and amination yield of 60% exhibited CO2 adsorption capacity of 4.52 mol/kg at ambient temperature and pressure.

  18. Pre-Transplant CDKN2A Expression in Kidney Biopsies Predicts Renal Function and Is a Future Component of Donor Scoring Criteria

    PubMed Central

    Gingell-Littlejohn, Marc; McGuinness, Dagmara; McGlynn, Liane M.; Kingsmore, David; Stevenson, Karen S.; Koppelstaetter, Christian; Clancy, Marc J.; Shiels, Paul G.

    2013-01-01

    CDKN2A is a proven and validated biomarker of ageing which acts as an off switch for cell proliferation. We have demonstrated previously that CDKN2A is the most robust and the strongest pre-transplant predictor of post- transplant serum creatinine when compared to “Gold Standard” clinical factors, such as cold ischaemic time and donor chronological age. This report shows that CDKN2A is better than telomere length, the most celebrated biomarker of ageing, as a predictor of post-transplant renal function. It also shows that CDKN2A is as strong a determinant of post-transplant organ function when compared to extended criteria (ECD) kidneys. A multivariate analysis model was able to predict up to 27.1% of eGFR at one year post-transplant (p = 0.008). Significantly, CDKN2A was also able to strongly predict delayed graft function. A pre-transplant donor risk classification system based on CDKN2A and ECD criteria is shown to be feasible and commendable for implementation in the near future. PMID:23861858

  19. Effect of low-level laser therapy irradiation and Bio-Oss graft material on the osteogenesis process in rabbit calvarium defects: a double blind experimental study.

    PubMed

    Rasouli Ghahroudi, Amir Alireza; Rokn, Amir Reza; Kalhori, Katayoun A M; Khorsand, Afshin; Pournabi, Alireza; Pinheiro, A L B; Fekrazad, Reza

    2014-05-01

    This study aims to assess the effect of low-level laser therapy (LLLT) irradiation and Bio-Oss graft material on the osteogenesis process in the rabbit calvarium defects. Twelve white male New Zealand rabbits were included in this study. Four 8-mm diameter identical defects were prepared on each rabbit's calvarium. One site was left as an untreated control (C), the second site was filled with Bio-Oss (B), the third site was treated with laser irradiation (L), and the fourth site treated with Bio-Oss and laser irradiation (B + L). In the laser group, a diode laser (wavelength 810 nm, output power 300 mW, irradiation mode CW, energy density 4 J/cm2) was applied immediately after surgery and then one other day for the next 20 days. After 4 and 8 weeks, the animals were sacrificed and histological and histomorphometric examinations were performed and the data were subjected to Friedman and repeated measurements ANOVA tests. Significant differences were not found regarding inflammation severity, foreign body reactions, and vitality of newly formed bone on 4th and 8th week after operation. The mean amount of new bone was 15.83 and 18.5% in the controls on the 4th and 8th week; 27.66 and 25.16% in the laser-irradiated group; 35.0 and 41.83% in Bio-Oss and 41.83 and 47.0% in the laser + Bio-Oss treated specimens with significant statistical differences (p <0.05). Application of LLLT in combination with Bio-Oss® can promote bone healing. Therefore, LLLT may be clinically beneficial in promoting bone formation in skeletal defects.

  20. Effect of pre-irradiation PPO-grafted maleic anhydride on structure and properties of PPO-g-MAH/PA66 blends

    NASA Astrophysics Data System (ADS)

    Li, Wenfei; Yao, Zhanhai; Yao, Ruixiang; Li, Xuan; Liu, Shumei

    2014-04-01

    The pre-irradiation polyphenylene oxide (PPO)-graft-maleic anhydride (PPO-g-MAH) was carried out by reactive extrusion. The chemical structure of PPO-g-MAH was characterized by means of Fourier-transform infrared spectroscopy. The wettability of PPO-g-MAH was characterized by the contact angle method. The blends of PPO-g-MAH/polyamide 66 (PA66) were prepared. Compared with the PPO/PA66 blends, mechanical properties of PPO-g-MAH/PA66 blends were distinctly improved. Smaller dispersed particle sizes with narrower distribution were found in PPO-g-MAH/PA66 blends, via field-emitted scanning electron microscopy. Rheological properties of PPO-g-MAH/PA66 blends were studied with a rotational rheometer.

  1. Raman ratios on the repair of grafted surgical bone defects irradiated or not with laser (λ780 nm) or LED (λ850 nm).

    PubMed

    Pinheiro, Antonio Luiz B; Soares, Luiz Guilherme P; Marques, Aparecida Maria C; Aciole, Jouber Mateus S; de Souza, Renato Aparecido; Silveira, Landulfo

    2014-09-01

    This work aimed to assess biochemical changes associated to mineralization and remodeling of bone defects filled with Hydroxyapatite+Beta-Beta-tricalcium phosphate irradiated or not with 2 light sources. Ratios of intensities, band position and bandwidth of selected Raman peaks of collagen and apatites were used. Sixty male Wistar rats were divided into 6 groups subdivided into 2 subgroups (15th and 30th days). A standard surgical defect was created on one femur of each animal. In 3 groups the defects were filled with blood clot (Clot, Clot+Laser and Clot+LED groups) and in the remaining 3 groups the defects were filled with biomaterial (Biomaterial, Biomaterial+Laser and Biomaterial+LED groups). When indicated, the defects were irradiated with either Laser (λ780 nm, 70 mW, Φ∼0.4 cm(2)) or LED (λ850±10 nm, 150 mW, Φ∼0.5 cm(2)), 20 J/cm(2) each session, at 48 h intervals/2 weeks (140 J/cm(2) treatment). Following sacrifice, bone fragments were analyzed by Raman spectroscopy. Statistical analysis (ANOVA General Linear Model, p<0.05) showed that both grafting and time were the variables that presented significance for the ratios of ∼1660/∼1670 cm(-1) (collagen maturation), ∼1077/∼854 cm(-1) (mineralization), ∼1077/∼1070 cm(-1) (carbonate substitution) and the position of the ∼960 cm(-1) (bone maturation). At 30th day, the ratios indicated an increased deposition of immature collagen for both Clot and Biomaterial groups. Biomaterial group showed increased collagen maturation. Only collagen deposition was significantly dependent upon irradiation independently of the light source, being the amount of collagen I increased in the Clot group at the end of the experimental time. On the other hand, collagen I deposition was reduced in biomaterial irradiated groups. Raman ratios of selected protein matrix and phosphate and carbonate HA indicated that the use of biphasic synthetic micro-granular HA+Beta-TCP graft improved the repair of bone defects

  2. Beneficial Effect of Short Pretransplant Period of Hypothermic Pulsatile Perfusion of the Warm-Ischemic Kidney after Cold Storage: Experimental Study

    PubMed Central

    Humanes, Blanca; Jado, Juan Carlos; Mojena, Marina; González-Nicolás, María Ángeles; del Cañizo, Juan Francisco; Lledó-García, Enrique

    2016-01-01

    Warm ischemia (WI) produces a significant deleterious effect in potential kidney grafts. Hypothermic machine perfusion (HMP) seems to improve immediate graft function after transplant. Our aim was to analyze the effect of short pretransplant periods of pulsatile HMP on histology and renal injury in warm-ischemic kidneys. Twelve minipigs were used. WI was achieved in the right kidney by applying a vascular clamp for 45 min. After nephrectomy, autotransplant was performed following one of two strategies: cold storage of the kidneys or cold storage combined with perfusion in pulsatile HMP. The graft was removed early to study renal morphology, inflammation (fibrosis), and apoptosis. Proinflammatory activity and fibrosis were less pronounced after cold storage of the kidneys with HMP than after cold storage only. The use of HMP also decreased apoptosis compared with cold storage only. The detrimental effects on cells of an initial and prolonged period of WI seem to improve with a preservation protocol that includes a short period of pulsatile HMP after cold storage and immediately before the transplant, in comparison with cold storage only. PMID:27556029

  3. Telemedicine Systems in Uterine Transplant: A Feasibility and Reliability Study of the Pre-Grafting Teleradiological Evaluation of the Uterus Graft.

    PubMed

    Mammas, Constantinos S; Saatsakis, George; Poulou, Loukia; Toulas, Panagiotis; Chasiakos, Demetrios

    2016-01-01

    The pre-grafting Tele-Radiological (TRE) evaluation of the Uterus Graft (UG) on Telemedicine Systems, in Uterus Transplant (UT) is studied by diagnostic sensitivity-specificity analysis based on simulation of TRE of the UG on 10 MR sets of female pelvic digital images by two radiologists, assessing a. The vascular variations of the grafts, and b. The inflammatory and neoplastic lesions of the UG. The pre-grafting TRE of the UG showed: a. Diagnostic unreliability for vascular variations, b. A high diagnostic reliability for inflammatory and neoplastic diseases of the UG (100%), making the MRI based TRE of the UG in UT, feasible and highly reliable for the remote pre-grafting diagnosis of UG pathologic lesions, but unreliable for integrated vascular anatomic and pathologic UG remote evaluation for pre-grafting and pre-transplant decision support and planning. PMID:27350456

  4. CsA-based post-graft immunosuppression: the main factor for improving outcome of allografted patients with acquired aplastic anemia. A retrospective survey by the Spanish Group of Hematopoietic Transplantation.

    PubMed

    Arranz, R; Conde, E; Rodriguez-Salvanés, F; Pajuelo, F J; Cabrera, R; Sanz, M A; Petit, J; Bueno, J; Maldonado, J; Odriozola, J; Conde, J G; Brunet, S; Carreras, E; Iriondo, A; Fernández-Rañada, J M; Marín, P

    2002-02-01

    A retrospective multicenter study was performed to assess the clinical results in patients with acquired aplastic anemia (AA) allografted over a 19 year period and to identify prognostic factors influencing survival. From April 1978 to December 1997, 176 patients were transplanted. Records from 160 receiving related matched bone marrow transplantation (BMT) were reviewed. Fifty-two percent of the patients were older than 20 years, 5% older than 40; 6.3% were untransfused at BMT and 56.2% had received prior treatments. Conditioning regimens were with chemotherapy in 43.7% of the procedures and with additional irradiation in 56.3%. Graft-versus-host disease (GVHD) prophylaxis was based on cyclosporin A (CsA) in 58.1% of the patients while methotrexate (MTX) was administered to 41.9%. Transplantation earlier on, a longer interval from diagnosis to BMT, GVHD prophylaxis with MTX, graft failure/rejection and acute severe GVHD were adverse factors for survival. The use of CsA emerged as the main factor for the improvement, inducing a significant decrease in graft failure/rejection rate and severe acute GVHD when compared with MTX alone. Radiation-containing regimens decreased the graft failure/rejection rate without improving survival due to the increased risk of acute GVHD. Age and number of transfusions pretransplant did not influence outcome. Survival achieved since 1991 is 79.79%, and graft failure and acute severe GVHD rates are 6.0% and 11.8%, respectively. In conclusion, CsA-based post-graft immunosuppression has been crucial in achieving improved survival in patients with acquired AA up to 40 years of age. Regardless of CsA use, further improvement in survival was apparent with time, probably due to better skills in patient care. PMID:11859392

  5. Bone Grafts

    MedlinePlus

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, ... fractures or cancers. Once your body accepts the bone graft, it provides a framework for growth of new, ...

  6. Intestinal microbiota-related effects on graft-versus-host disease

    PubMed Central

    Shono, Yusuke; Docampo, Melissa D.; Peled, Jonathan U.; Perobelli, Suelen M.; Jenq, Robert R.

    2016-01-01

    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an increasingly important treatment for conditions including hematopoietic malignancies and inherited hematopoietic disorders, and is considered to be the most effective form of tumor immunotherapy available to date. However, graft-versus-host disease (GVHD) remains a major source of morbidity and mortality following allo-HSCT, and understanding the mechanisms of GVHD has been highlighted as a key research priority. During development of GVHD, activation of various immune cells, especially donor T cells, leads to damage of target organs including skin, liver, hematopoietic system, and of particular clinical importance, gut. In addition to histocompatibility complex differences between the donor and recipient, pre-transplant conditioning with chemotherapy and irradiation also contributes to GVHD by damaging the gut, resulting in systemic exposure to microbial products normally confined to the intestinal lumen. The intestinal microbiota is a modulator of gastrointestinal immune homeostasis. It also promotes the maintenance of epithelial cells. Recent reports provide growing evidence of the impact of intestinal microbiota on GVHD pathophysiology. This review summarizes current knowledge of changes and effects of intestinal microbiota in the setting of allo-HSCT. We will also discuss potential future strategies of intestinal-microbiota manipulation that might be advantageous in decreasing allo-HSCT related morbidity and mortality. PMID:25812838

  7. New variant for whole pancreas grafting

    SciTech Connect

    Kootstra, G.; van Hooff, J.P.; Joerning, P.J.L.; Leunissen, K.M.; van der Linden, C.J.; Beukers, E.; Buurman, W.A.

    1987-02-01

    A new variant for whole pancreas grafting is described in which a segment of the duodenum and the spleen is included in the graft. The graft is placed extraperitoneally as in kidney transplantation. The exocrine drainage is with side-to-side anastomosis between duodenum and bladder. The spleen is irradiated to prevent the occurrence of GVHD, as is reported in splenic transplantation.

  8. Treatment of aggressive multiple myeloma by high-dose chemotherapy and total body irradiation followed by blood stem cells autologous graft

    SciTech Connect

    Fermand, J.P.; Levy, Y.; Gerota, J.; Benbunan, M.; Cosset, J.M.; Castaigne, S.; Seligmann, M.; Brouet, J.C.

    1989-01-01

    Eight patients with stage III aggressive multiple myeloma, refractory to current chemotherapy in six cases, were treated by high-dose chemotherapy (nitrosourea, etoposide, and melphalan) (HDC) and total body irradiation (TBI), followed by autografting with blood stem cells. These cells were previously collected by leukapheresis performed during hematologic recovery following cytotoxic drug-induced bone marrow aplasia. Seven patients were alive 9 to 17 months after HDC-TBI and graft. One died at day 40 from cerebral bleeding. All living patients achieved a 90% or greater reduction in tumor mass. In two cases, a complete remission (CR) has persisted at a follow-up of 15 and 16 months. Three patients have been well and off therapy with stable minimal residual disease (RD) since 10, 11, and 17 months, respectively. A patient in apparent CR and another with RD have relapsed 9 to 12 months posttreatment. Autologous blood-derived hematopoietic stem cells induced successful and sustained engraftment in all living patients. These results, although still preliminary, indicate that HDC and TBI, followed by blood stem cells autograft, which has both practical and theoretical interest over allogeneic or autologous bone marrow transplantation, deserve consideration in selected patients with multiple myeloma.

  9. Longitudinal trajectory of sexual functioning after hematopoietic cell transplantation: impact of chronic graft-versus-host disease and total body irradiation

    PubMed Central

    Wong, F. Lennie; Francisco, Liton; Togawa, Kayo; Kim, Heeyoung; Bosworth, Alysia; Atencio, Liezl; Hanby, Cara; Grant, Marcia; Kandeel, Fouad; Forman, Stephen J.

    2013-01-01

    This prospective study described the trajectory of sexual well-being from before hematopoietic cell transplantation (HCT) to 3 years after in 131 allogeneic and 146 autologous HCT recipients using Derogatis Interview for Sexual Function and Derogatis Global Sexual Satisfaction Index. Sixty-one percent of men and 37% of women were sexually active pre-HCT; the prevalence declined to 51% (P = .01) in men and increased to 48% (P = .02) in women at 3 years post-HCT. After HCT, sexual satisfaction declined in both sexes (P < .001). All sexual function domains were worse in women compared with men (P ≤ .001). Orgasm (P = .002) and drive/relationship (P < .001) declined in men, but sexual cognition/fantasy (P = .01) and sexual behavior/experience (P = .01) improved in women. Older age negatively impacted sexual function post-HCT in both sexes (P < .01). Chronic graft-versus-host disease was associated with lower sexual cognition/fantasy (P = .003) and orgasm (P = .006) in men and sexual arousal (P = .05) and sexual satisfaction (P = .005) in women. All male sexual function domains declined after total body irradiation (P < .05). This study identifies vulnerable subpopulations that could benefit from interventional strategies to improve sexual well-being. PMID:24159171

  10. Subclinical pulmonary function defects following autologous and allogeneic bone marrow transplantation: relationship to total body irradiation and graft-versus-host disease

    SciTech Connect

    Tait, R.C.; Burnett, A.K.; Robertson, A.G.; McNee, S.; Riyami, B.M.; Carter, R.; Stevenson, R.D. )

    1991-06-01

    Pulmonary function results pre- and post-transplant, to a maximum of 4 years, were analyzed in 98 patients with haematological disorders undergoing allogeneic (N = 53) or autologous bone marrow transplantation (N = 45) between 1982 and 1988. All received similar total body irradiation based regimens ranging from 9.5 Gy as a single fraction to 14.4 Gy fractionated. FEV1/FVC as a measure of airway obstruction showed little deterioration except in patients experiencing graft-versus-host disease in whom statistically significant obstructive ventilatory defects were evident by 6 months post-transplant (p less than 0.01). These defects appeared to be permanent. Restrictive ventilatory defects, as measured by reduction in TLC, and defects in diffusing capacity (DLCO and KCO) were also maximal at 6 months post-transplant (p less than 0.01). Both were related, at least in part, to the presence of GVHD (p less than 0.01) or use of single fraction TBI with absorbed lung dose of 8.0 Gy (p less than 0.05). Fractionated TBI resulted in less marked restricted ventilation and impaired gas exchange, which reverted to normal by 2 years, even when the lung dose was increased from 11.0 Gy to between 12.0 and 13.5 Gy. After exclusion of patients with GVHD (30% allografts) there was no significant difference in pulmonary function abnormalities between autograft and allograft recipients.

  11. Total lymphoid irradiation in kidney and liver transplantation in the baboon: prolonged graft survival and alterations in T cell subsets with low cumulative dose regimens

    SciTech Connect

    Myburgh, J.A.; Smith, J.A.; Stark, J.H.; Browde, S.

    1984-02-01

    Prolonged kidney and liver allograft survival was produced in baboons by low cumulative doses (500 to 1200 rad) of total lymphoid irradiation (TLI). Continuing normal graft function for more than 1 year after transplantation was seen in 10 animals in this series. The longest survivor (> 4 years) rejected a third party kidney allograft in typically acute fashion 1 yr after the original transplantation. The dose-response effect was parabolic, with a cumulative dose of 800 rad given as twice weekly fractions of 100 rad each being the most effective. With smaller cumulative doses (500 or 600 rad) results were improved if TLI was administered as a large number of smaller fractions. These regimens are free of the radiation related mortality observed in earlier studies with larger cumulative doses. Alterations in T cell subpopulations were studied in these baboons with the use of the anti-human monoclonal antibodies OKT11 (anti-total T cells), OKT4 (anti-T helper cells; Th), and OKT8 (anti-T suppressor/cytotoxic cells, Tsc), which cross-react with baboon lymphocytes. After completion of TLI but before transplantation, the relative percentage of Tsc cells fell and the percentage of Th and the Th/Tsc ratio rose. Transplantation was followed by an inversion of this ratio due to reciprocal changes in the percentages of Th and Tsc cells. This pattern persisted and increased until 6 mo after transplantation, when it reverted to that seen in untreated control animals.

  12. Radiation grafting on natural films

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  13. Radiation grafting of styrene onto polyethylene

    NASA Astrophysics Data System (ADS)

    Izumi, Yoshinobu; Nagaike, Hiroshi; Tabuse, Shigehiko; Yoshida, Yoichi; Tagawa, Seiichi

    2001-07-01

    In order to improve the radiation stability of aliphatic polymers, radiation-induced graft polymerization of styrene onto low-density polyethylene (LDPE) has been studied. Two methods, namely, simultaneous irradiation and pre-irradiation method, were treated. In the case of simultaneous irradiation, it was indicated from the dependency of percent graft on monomer concentration and absorbed dose that grafting efficiency was reduced by the increase in the homo-polymerization of styrene. On the other hand, more highly grafting polymer could be prepared by the pre-irradiation method. Depth-profile of grafted phenyl ring was also analyzed by means of micro-FT-IR spectroscopy. Recently, radiation stability of the obtained graft polymer was tested.

  14. Pretransplant echocardiographic parameters as markers of posttransplant outcomes in liver transplant recipients.

    PubMed

    Bushyhead, Daniel; Kirkpatrick, James N; Goldberg, David

    2016-03-01

    Despite advances in liver transplantation and preoperative risk stratification, there remains significant posttransplant morbidity and mortality from cardiovascular and renal disease. There are limited and conflicting data on the role of pretransplant echocardiography to predict these outcomes. The purpose of our study was to determine if pretransplant echocardiographic parameters were associated with posttransplant survival and the development of incident cardiovascular events and chronic kidney disease (CKD). We conducted a retrospective cohort study of 397 adult liver transplant recipients at the University of Pennsylvania from January 1, 2005 to September 30, 2014. Patients with acute liver failure, those without a diagnosis of cirrhosis (eg, polycystic liver disease without portal hypertension), retransplants, and multiorgan transplants were excluded. In multivariable Cox regression models, tricuspid regurgitation graded greater than mild was associated with significantly increased posttransplant mortality (hazard ratio, 1.68; 95% confidence interval [CI], 1.03-2.75; P = 0.04). In multivariable competing risk models, increasing pulmonary artery systolic pressure (PASP) was associated with significantly increased risk of hospitalization for myocardial infarction or heart failure (subhazard ratio per 5 mm Hg increase in PASP, 1.79; 95% CI, 1.48-2.17; P < 0.001). In multivariable competing risk models, increased left ventricular ejection fraction (LVEF) was associated with a numerical but nonsignificant increased risk of stage 4 or 5 CKD (subhazard ratio, 1.11 per 5% increase in LVEF; 95% CI, 0.99-1.24; P = 0.07). In a post hoc analysis, LVEF ≥ 65% was the best cutoff for increased risk of CKD (subhazard ratio, 1.75; 95% CI, 1.06-2.89; P = 0.03). In conclusion, several pretransplant echocardiographic parameters were associated with posttransplant morbidity and mortality, suggesting that pretransplant echocardiography may be used as a tool to risk

  15. Properties of starch-polyglutamic acid (PGA) graft copolymer prepared by microwave irradiation - Fourier transform infrared spectroscopy (FTIR) and rheology studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rheological properties of waxy starch-'-polygutamic acid (PGA) graft copolymers were investigated. Grafting was confirmed by FTIR spectroscopy. The starch-PGA copolymers absorbed water and formed gels, which exhibited concentration-dependent viscoelastic solid properties. Higher starch-PGA conce...

  16. Plant grafting.

    PubMed

    Melnyk, Charles W; Meyerowitz, Elliot M

    2015-03-01

    Since ancient times, people have cut and joined together plants of different varieties or species so they would grow as a single plant - a process known as grafting (Figures 1 and 2). References to grafting appear in the Bible, ancient Greek and ancient Chinese texts, indicating that grafting was practised in Europe, the Middle East and Asia by at least the 5(th) century BCE. It is unknown where or how grafting was first discovered, but it is likely that natural grafting, the process by which two plants touch and fuse limbs or roots in the absence of human interference (Figure 3), influenced people's thinking. Such natural grafts are generally uncommon, but are seen in certain species, including English ivy. Parasitic plants, such as mistletoe, that grow and feed on often unrelated species may have also contributed to the development of grafting as a technique, as people would have observed mistletoe growing on trees such as apples or poplars. PMID:25734263

  17. Identification of Molecular Markers of Delayed Graft Function Based on the Regulation of Biological Ageing

    PubMed Central

    McGuinness, Dagmara; Leierer, Johannes; Shapter, Olivier; Mohammed, Suhaib; Gingell-Littlejohn, Marc; Kingsmore, David B.; Little, Ann-Margaret; Kerschbaum, Julia; Schneeberger, Stefan; Maglione, Manuel; Nadalin, Silvio; Wagner, Sylvia; Königsrainer, Alfred; Aitken, Emma; Whalen, Henry; Clancy, Marc; McConnachie, Alex; Koppelstaetter, Christian; Stevenson, Karen S.; Shiels, Paul G.

    2016-01-01

    Introduction Delayed graft function is a prevalent clinical problem in renal transplantation for which there is no objective system to predict occurrence in advance. It can result in a significant increase in the necessity for hospitalisation post-transplant and is a significant risk factor for other post-transplant complications. Methodology The importance of microRNAs (miRNAs), a specific subclass of small RNA, have been clearly demonstrated to influence many pathways in health and disease. To investigate the influence of miRNAs on renal allograft performance post-transplant, the expression of a panel of miRNAs in pre-transplant renal biopsies was measured using qPCR. Expression was then related to clinical parameters and outcomes in two independent renal transplant cohorts. Results Here we demonstrate, in two independent cohorts of pre-implantation human renal allograft biopsies, that a novel pre-transplant renal performance scoring system (GRPSS), can determine the occurrence of DGF with a high sensitivity (>90%) and specificity (>60%) for donor allografts pre-transplant, using just three senescence associated microRNAs combined with donor age and type of organ donation. Conclusion These results demonstrate a relationship between pre-transplant microRNA expression levels, cellular biological ageing pathways and clinical outcomes for renal transplantation. They provide for a simple, rapid quantitative molecular pre-transplant assay to determine post-transplant allograft function and scope for future intervention. Furthermore, these results demonstrate the involvement of senescence pathways in ischaemic injury during the organ transplantation process and an indication of accelerated bio-ageing as a consequence of both warm and cold ischaemia. PMID:26734715

  18. Pretransplant NPM1 MRD levels predict outcome after allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia

    PubMed Central

    Kayser, S; Benner, A; Thiede, C; Martens, U; Huber, J; Stadtherr, P; Janssen, J W G; Röllig, C; Uppenkamp, M J; Bochtler, T; Hegenbart, U; Ehninger, G; Ho, A D; Dreger, P; Krämer, A

    2016-01-01

    The objective was to evaluate the prognostic impact of pre-transplant minimal residual disease (MRD) as determined by real-time quantitative polymerase chain reaction in 67 adult NPM1-mutated acute myeloid leukemia patients receiving allogeneic hematopoietic stem cell transplantation (HSCT). Twenty-eight of the 67 patients had a FLT3-ITD (42%). Median age at transplantation was 54.7 years, median follow-up for survival from time of allografting was 4.9 years. At transplantation, 31 patients were in first, 20 in second complete remission (CR) and 16 had refractory disease (RD). Pre-transplant NPM1 MRD levels were measured in 39 CR patients. Overall survival (OS) for patients transplanted in CR was significantly longer as compared to patients with RD (P=0.004), irrespective of whether the patients were transplanted in first or second CR (P=0.74). There was a highly significant difference in OS after allogeneic HSCT between pre-transplant MRD-positive and MRD-negative patients (estimated 5-year OS rates of 40 vs 89% P=0.007). Multivariable analyses on time to relapse and OS revealed pre-transplant NPM1 MRD levels >1% as an independent prognostic factor for poor survival after allogeneic HSCT, whereas FLT3-ITD had no impact. Notably, outcome of patients with pre-transplant NPM1 MRD positivity >1% was as poor as that of patients transplanted with RD. PMID:27471865

  19. Pre-transplant thymic function is associated with the risk of cytomegalovirus disease after solid organ transplantation.

    PubMed

    Gracia-Ahufinger, I; Ferrando-Martínez, S; Montejo, M; Muñoz-Villanueva, M C; Cantisán, S; Rivero, A; Solana, R; Leal, M; Torre-Cisneros, J

    2015-05-01

    Cytomegalovirus (CMV) disease is an important complication in solid organ transplant recipients. Thymic function in adults is associated with specific T-cell immunity. Pre-transplant thymic function was analysed in 75 solid organ transplant patients by the use of nested PCR. The primary outcome was the incidence of CMV disease 12 months after transplantation. Using multivariable logistic regression, we studied whether pre-transplant thymic function is an independent risk factor for CMV disease after transplantation. Thymic function was related to the risk of CMV disease in CMV-seropositive recipients. In these recipients, pre-transplant thymic function of <9.5 (OR 11.27, 95% CI 1.11-114.43, p 0.040) and the use of thymoglobulin (OR 8.21, 95% CI 1.09-61.84, p 0.041) were independent risk factors for CMV disease at 12 months after transplantation. Patients with pre-transplant thymic function values of <9.5 had a higher subsequent incidence of CMV disease (24%) than patients with values of ≥ 9.5 (3%) (log-rank test: 5.727; p 0.017). The positive and negative predictive values of these pre-transplant thymic function cut-offs were 0.24 (95% CI 0.10-0.45) and 0.97 (95% CI 0.82-1.00), respectively. Pre-transplant thymic function in CMV-seropositive candidates could be useful in determining the risk of post-transplant CMV disease in solid organ transplant patients, selecting a group of low-risk candidates.

  20. Long-Term Outcomes after Treatment with Clofarabine ± Fludarabine with Once-Daily Intravenous Busulfan as Pretransplant Conditioning Therapy for Advanced Myeloid Leukemia and Myelodysplastic Syndrome.

    PubMed

    Alatrash, Gheath; Thall, Peter F; Valdez, Benigno C; Fox, Patricia S; Ning, Jing; Garber, Haven R; Janbey, Selma; Worth, Laura L; Popat, Uday; Hosing, Chitra; Alousi, Amin M; Kebriaei, Partow; Shpall, Elizabeth J; Jones, Roy B; de Lima, Marcos; Rondon, Gabriela; Chen, Julianne; Champlin, Richard E; Andersson, Borje S

    2016-10-01

    Pretransplant conditioning regimens critically determine outcomes in the setting of allogeneic stem cell transplantation (allo-SCT). The use of nucleoside analogs such as fludarabine (Flu) in combination with i.v. busulfan (Bu) has been shown to be highly effective as a pretransplant conditioning regimen in acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and myelodysplastic syndrome (MDS). Because leukemia relapse remains the leading cause of death after allo-SCT, we studied whether clofarabine (Clo), a nucleoside analog with potent antileukemia activity, can be used to complement Flu. In a preliminary report, we previously showed the safety and efficacy of Clo ± Flu with i.v. Bu in 51 patients with high-risk AML, CML, and MDS. The study has now been completed, and we present long-term follow-up data on the entire 70-patient population, which included 49 (70%), 8 (11%), and 13 (19%) patients with AML, MDS, and CML, respectively. Thirteen patients (19%) were in complete remission, and 41 patients (59%) received matched unrelated donor grafts. Engraftment was achieved in all patients. Sixty-three patients (90%) achieved complete remission. There were no deaths reported at day +30, and the 100-day nonrelapse mortality rate was 4% (n = 3). Thirty-one percent of patients (n = 22) developed grades II to IV acute graft-versus-host disease, and the median overall survival and progression-free survival times were 2.4 years and .9 years, respectively. Our results confirm the safety and overall and progression-free survival advantage of the arms with higher Clo doses and lower Flu doses, which was most prominent in the AML/MDS group.

  1. The impact of pre-transplant minimal residual disease on outcome of intensified myeloablative cord blood transplant for acute myeloid leukemia in first or second complete remission.

    PubMed

    Zheng, Changcheng; Zhu, Xiaoyu; Tang, Baolin; Zhang, Lei; Geng, Liangquan; Liu, Huilan; Sun, Zimin

    2016-01-01

    The impact of pretransplant minimal residual disease (MRD) on outcome of myeloablative cord blood transplant (CBT) for acute myeloid leukemia (AML) in complete remission (CR) has not been reported. Seventy-two AML patients were assessed for MRD before CBT, and the majority (84.7%) of these patients received single-unit CBT. All patients received intensified myeloablative conditioning with BUCY2 or TBICY plus high-dose cytarabine, and graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil. The cumulative incidences of neutrophil and platelet engraftment, acute or chronic GVHD were comparable between MRD-negative and MRD-positive groups. The cumulative incidence of transplant-related mortality (TRM) and relapse did not differ significantly between the two cohorts (25.6% vs. 32.5%, 16.1% vs. 19.2%; p = 0.52, 0.61). There were no apparent differences in 3-year overall survival (OS) (68.9% in MRD-negative group and 57.9% in MRD-positive group, p = 0.31) and 3-year leukemia-free survival (LFS) (62.5% in MRD-negative group and 52.7% in MRD-positive group, p = 0.42) between both groups. The current study suggests that AML patients in morphological CR1 or CR2 who have detectable MRD might benefit from unrelated CBT with intensified myeloablative conditioning. PMID:26690538

  2. The impact of pre-transplant minimal residual disease on outcome of intensified myeloablative cord blood transplant for acute myeloid leukemia in first or second complete remission.

    PubMed

    Zheng, Changcheng; Zhu, Xiaoyu; Tang, Baolin; Zhang, Lei; Geng, Liangquan; Liu, Huilan; Sun, Zimin

    2016-01-01

    The impact of pretransplant minimal residual disease (MRD) on outcome of myeloablative cord blood transplant (CBT) for acute myeloid leukemia (AML) in complete remission (CR) has not been reported. Seventy-two AML patients were assessed for MRD before CBT, and the majority (84.7%) of these patients received single-unit CBT. All patients received intensified myeloablative conditioning with BUCY2 or TBICY plus high-dose cytarabine, and graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil. The cumulative incidences of neutrophil and platelet engraftment, acute or chronic GVHD were comparable between MRD-negative and MRD-positive groups. The cumulative incidence of transplant-related mortality (TRM) and relapse did not differ significantly between the two cohorts (25.6% vs. 32.5%, 16.1% vs. 19.2%; p = 0.52, 0.61). There were no apparent differences in 3-year overall survival (OS) (68.9% in MRD-negative group and 57.9% in MRD-positive group, p = 0.31) and 3-year leukemia-free survival (LFS) (62.5% in MRD-negative group and 52.7% in MRD-positive group, p = 0.42) between both groups. The current study suggests that AML patients in morphological CR1 or CR2 who have detectable MRD might benefit from unrelated CBT with intensified myeloablative conditioning.

  3. Preoperative risk factor analysis in orthotopic liver transplant-ation with pretransplant artificial liver support therapy

    PubMed Central

    Yuan, Jin-Zhong; Ye, Qi-Fa; Zhao, Ling-Ling; Ming, Ying-Zi; Sun, Hong; Zhu, Shai-Hong; Huang, Zu-Fa; Wang, Min-Min

    2006-01-01

    AIM: To assess the value of pre-transplant artificial liver support in reducing the pre-operative risk factors relating to early mortality after orthotopic liver transplantation (OLT). METHODS: Fifty adult patients with various stages and various etiologies undergoing OLT procedures were treated with molecular adsorbent recycling system (MARS) as preoperative liver support therapy. The study included two parts, the first one is to evaluate the medical effectiveness of single MARS treatment with some clinical and laboratory parameters, which were supposed to be the therapeutical pre-transplant risk factors, the second part is to study the patients undergoing OLT using the regression analysis on preoperative risk factors relating to early mortality (30 d) after OLT. RESULTS: In the 50 patients, the statistically significant improvement in the biochemical parameters was observed (pre-treatment and post-treatment). Eight patients avoided the scheduled Ltx due to significant relief of clinical condition or recovery of failing liver function, 8 patients died, 34 patients were successfully bridged to Ltx, the immediate outcome of this 34 patients within 30d observation was: 28 kept alive and 6 patients died. CONCLUSION: Pre-operative SOFA, level of creatinine, INR, TNF-α, IL-10 are the main preoperative risk factors that cause early death after operation, MARS treatment before transplantion can relieve these factors significantly. PMID:16937506

  4. Impact of pretransplant body mass index on the clinical outcome after allogeneic hematopoietic SCT.

    PubMed

    Fuji, S; Takano, K; Mori, T; Eto, T; Taniguchi, S; Ohashi, K; Sakamaki, H; Morishima, Y; Kato, K; Miyamura, K; Suzuki, R; Fukuda, T

    2014-12-01

    To elucidate the impact of pretransplant body mass index (BMI) on the clinical outcome, we performed a retrospective study with registry data including a total of 12 050 patients (age ⩾18 years) who received allogeneic hematopoietic SCT (HSCT) between 2000 and 2010. Patients were stratified as follows: BMI<18.5 kg/m(2), Underweight, n=1791; 18.5⩽BMI<25, Normal, n=8444; 25⩽BMI<30, Overweight, n=1591; BMI⩾30, Obese, n=224. The median age was 45 years (range, 18-77). A multivariate analysis showed that the risk of relapse was significantly higher in the underweight group and lower in the overweight and obese groups compared with the normal group (hazard ratio (HR), 1.16, 0.86, and 0.74, respectively). The risk of GVHD was significantly higher in the overweight group compared with the normal group. The risk of non-relapse mortality (NRM) was significantly higher in the overweight and obese group compared with the normal group (HR 1.19 and HR 1.43, respectively). The probability of OS was lower in the underweight group compared with the normal group (HR 1.10, P=0.018). In conclusion, pretransplant BMI affected the risk of relapse and NRM after allogeneic HSCT. Underweight was a risk factor for poor OS because of an increased risk of relapse. Obesity was a risk factor for NRM.

  5. Pre-transplant weight loss predicts inferior outcome after allogeneic stem cell transplantation in patients with myelodysplastic syndrome.

    PubMed

    Radujkovic, Aleksandar; Becker, Natalia; Benner, Axel; Penack, Olaf; Platzbecker, Uwe; Stölzel, Friedrich; Bornhäuser, Martin; Hegenbart, Ute; Ho, Anthony D; Dreger, Peter; Luft, Thomas

    2015-10-27

    Allogeneic stem cell transplantation (alloSCT) represents a curative therapeutic option for patients with myelodysplastic syndrome (MDS), but relapse and non-relapse mortality (NRM) limit treatment efficacy. Based on our previous observation in acute myeloid leukemia we investigated the impact of pre-transplant weight loss on post-transplant outcome in MDS patients. A total of 111 patients diagnosed with MDS according to WHO criteria transplanted between 2000 and 2012 in three different transplant centers were included into the analysis. Data on weight loss were collected from medical records prior to conditioning therapy and 3-6 months earlier. Patient, disease and transplant characteristics did not differ between patients with weight loss (2-5%, n = 17; > 5%, n = 17) and those without (n = 77). In a mixed effect model, weight loss was associated with higher risk MDS (p = 0.046). In multivariable analyses, pre-transplant weight loss exceeding 5% was associated with a higher incidence of relapse (p < 0.001) and NRM (p = 0.007). Pre-transplant weight loss of 2-5% and > 5% were independent predictors of worse disease-free (p = 0.023 and p < 0.001, respectively) and overall survival (p = 0.043 and p < 0.001, respectively). Our retrospective study suggests that MDS patients losing weight prior to alloSCT have an inferior outcome after transplantation. Prospective studies addressing pre-transplant nutritional interventions are highly warranted.

  6. Pre-transplant weight loss predicts inferior outcome after allogeneic stem cell transplantation in patients with myelodysplastic syndrome

    PubMed Central

    Radujkovic, Aleksandar; Becker, Natalia; Benner, Axel; Penack, Olaf; Platzbecker, Uwe; Stölzel, Friedrich; Bornhäuser, Martin; Hegenbart, Ute; Ho, Anthony D.; Dreger, Peter; Luft, Thomas

    2015-01-01

    Allogeneic stem cell transplantation (alloSCT) represents a curative therapeutic option for patients with myelodysplastic syndrome (MDS), but relapse and non-relapse mortality (NRM) limit treatment efficacy. Based on our previous observation in acute myeloid leukemia we investigated the impact of pre-transplant weight loss on post-transplant outcome in MDS patients. A total of 111 patients diagnosed with MDS according to WHO criteria transplanted between 2000 and 2012 in three different transplant centers were included into the analysis. Data on weight loss were collected from medical records prior to conditioning therapy and 3–6 months earlier. Patient, disease and transplant characteristics did not differ between patients with weight loss (2–5%, n = 17; > 5%, n = 17) and those without (n = 77). In a mixed effect model, weight loss was associated with higher risk MDS (p = 0.046). In multivariable analyses, pre-transplant weight loss exceeding 5% was associated with a higher incidence of relapse (p < 0.001) and NRM (p = 0.007). Pre-transplant weight loss of 2–5% and > 5% were independent predictors of worse disease-free (p = 0.023 and p < 0.001, respectively) and overall survival (p = 0.043 and p < 0.001, respectively). Our retrospective study suggests that MDS patients losing weight prior to alloSCT have an inferior outcome after transplantation. Prospective studies addressing pre-transplant nutritional interventions are highly warranted. PMID:26360778

  7. Impact of failed allograft nephrectomy on initial function and graft survival after kidney retransplantation.

    PubMed

    Schleicher, Christina; Wolters, Heiner; Kebschull, Linus; Anthoni, Christoph; Suwelack, Barbara; Senninger, Norbert; Palmes, Daniel; Mersfeld, Bernadette

    2011-03-01

    The management of an asymptomatic failed renal graft remains controversial. The aim of our study was to explore the effect of failed allograft nephrectomy on kidney retransplantation by comparing the outcome of recipients who underwent graft nephrectomy prior to retransplantation with those who did not. Retrospective comparison of patients undergoing kidney retransplantation with (group A, n = 121) and without (group B, n = 45) preliminary nephrectomy was performed, including subgroup analysis with reference to patients with multiple (≥2) retransplantations and patients of the European Senior Program (ESP). Nephrectomy leads to increased panel reactive antibody (PRA) levels prior to retransplantation and is associated with significantly increased rates of primary nonfunction (PNF; P = 0.05) and acute rejection (P = 0.04). Overall graft survival after retransplantation was significantly worse in group A compared with group B (P = 0.03). Among the subgroups especially ESP patients showed a shorter graft survival after previous allograft nephrectomy. On the multivariate analysis, pretransplant graft nephrectomy and PRA >70% were independent and significant risk factors associated with graft loss after kidney retransplantation. Nephrectomy of the failed allograft was not beneficial for retransplant outcome in our series. Patients with failed graft nephrectomy tended to have a higher risk of PNF and acute rejection after retransplantation. The possibility that the graft nephrectomy has a negative impact on graft function and survival after retransplantation is worth studying further.

  8. Promoting Access to Renal Transplantation: The Role of Social Support Networks in Completing Pre-transplant Evaluations

    PubMed Central

    Hicks, Leroi S.; Keogh, Joseph H.; Epstein, Arnold M.; Ayanian, John Z.

    2008-01-01

    Background Completing pre-transplant evaluations may be a greater barrier to renal transplantation for blacks with end-stage renal disease (ESRD) than for whites. Objective To determine whether social support networks facilitate completing the pre-transplant evaluation and reduce racial disparities in this aspect of care. Design, Setting, and Participants We surveyed 742 black and white ESRD patients in four regional networks 9 months after they initiated dialysis in 1996 and 1997. Patients reported instrumental support networks (number of friends or family to help with daily activities), emotional support networks (number of friends or family available for counsel on personal problems) and dialysis center support (support from dialysis center staff and patients). The completion of pre-transplant evaluations, including preoperative risk stratification and testing, was determined by medical record reviews. Outcome Measurement Complete renal pre-transplant evaluations. Results Compared to patients with low levels of instrumental support, those with high levels were more likely to have complete evaluations (25% versus 46%, respectively, p < .001). In adjusted analyses, high levels of instrumental support were associated with higher rates of complete evaluations among black women (p < .05), white women (p < .05), and white men (p < .05), but not black men. Among black men, but not other groups, private insurance was a significant predictor of complete evaluations. Conclusions Instrumental support networks may facilitate completing renal pre-transplant evaluations. Clinical interventions that supplement instrumental support should be evaluated to improve access to renal transplantation. Access to supplemental insurance may also promote complete evaluations for black patients. PMID:18478302

  9. Study on thermal properties and crystallization behavior of electron beam irradiated ethylene vinyl acetate (EVA)/waste tyre dust (WTD) blends in the presence of polyethylene graft maleic anhydride (PEgMAH)

    SciTech Connect

    Ramli, Syuhada; Ahmad, S. H.; Ratnam, C. T.; Athirah, Nurul

    2013-11-27

    The aim of this article is to show the effects of the electron beam irradiation dose and presence of a compatibiliser on the thermal properties and crystallinity of EVA/WTD blends. The purpose of applying electron beam radiation with doses range 50 to 200 kGy and adding a compatibiliser was to enhance the compatibility of the studied blends and at the same time to investigate the possibility of using this technique in the process of recycling polymeric materials. As the compatibilisers, the polyethylene grafted maleic anhydride (PEgMAH) was utilized, they were added at the amounts of 1-5 phr respectively. The enhancement of thermal properties was accompanied by the following effects, discussed in this article: i) an irradiated EVA/WTD blend at 200kGy was found to improve the thermal properties of EVA, ii) the addition of PEgMAH in EVA/WTD blends and the subsequent irradiation allowed prevention of degradation mechanism. iii) the ΔH{sub f} and crystallinity percentage decrease at higher PEgMAH content.

  10. Physician predictions of graft survival following liver transplantation

    PubMed Central

    Feurer, Irene D.; Austin, Mary T.; Porayko, Michael K.; Wright, J. Kelly; Lorenzi, Nancy M.; Pinson, C. Wright; Aronsky, Dominik

    2007-01-01

    Introduction. Due to the scarcity of cadaveric livers, clinical judgment must be used to avoid futile transplants. However, the accuracy of human judgment for predicting outcomes following liver transplantation is unknown. The study aim was to assess expert clinicians’ ability to predict graft survival and to compare their performance to published survival models. Materials and methods. Pre-transplant case summaries were prepared based on 16 actual, randomly selected liver transplants. Clinicians specializing in the care of liver transplant patients were invited to assess the likelihood of 90-day graft survival for each case using (1) a 4-point Likert scale ranging from poor to excellent, and (2) a visual analog scale denoting the probability of survival. Four published models were also used to predict survival for the 16 cases. Results. Completed instruments were received from 50 clinicians. Prognostic estimates on the two scales were highly correlated (median r=0.88). Individual clinicians’ predictive ability was 0.61±0.13, by area under the receiver operating characteristic curve. The performance of published models was MELD 0.59, Desai 0.66, Ghobrial 0.61, and Thuluvath 0.45. For three cases, clinicians consistently overestimated the probability of survival (87±10%, 89±9%, 86±9%); these patients had early graft failures caused by postoperative complications. Discussion. Clinicians varied in their ability to predict survival for a set of pre-transplant scenarios, but performed similarly to published models. When clinicians overestimated the chance of transplant success, either sepsis or hepatic artery thrombosis was involved; such events may be hard to predict before surgery. PMID:18345303

  11. Pre-transplant shedding of BK virus in urine is unrelated to post-transplant viruria and viremia in kidney transplant recipients.

    PubMed

    Bicalho, C S; Oliveira, R R; Pierrotti, L C; Fink, M C D S; Urbano, P R P; Nali, L H S; Luna, E J A; Romano, C M; David, D R; David-Neto, E; Pannuti, C S

    2016-07-01

    BK virus-(BKV) associated nephropathy (BKVN) is a major cause of allograft injury in kidney transplant recipients. In such patients, subclinical reactivation of latent BKV infection can occur in the pre-transplant period. The purpose of this study was to determine whether urinary BKV shedding in the immediate pre-transplant period is associated with a higher incidence of viruria and viremia during the first year after kidney transplantation. We examined urine samples from 34 kidney transplant recipients, using real-time quantitative polymerase chain reaction to detect BKV. Urine samples were obtained in the immediate pre-transplant period and during the first year after transplant on a monthly basis. If BKV viruria was detected, blood samples were collected and screened for BKV viremia. In the immediate pre-transplant period, we detected BKV viruria in 11 (32.3%) of the 34 recipients. During the first year after transplantation, we detected BKV viruria in all 34 patients and viremia in eight (23.5%). We found no correlation between pre-transplant viruria and post-transplant viruria or viremia (p = 0.2). Although reactivation of latent BKV infection in the pre-transplant period is fairly common among kidney transplant recipients, it is not a risk factor for post-transplant BKV viruria or viremia.

  12. Impact of Pre-transplant Therapy and Depth of Disease Response prior to Autologous Transplantation for Multiple Myeloma

    PubMed Central

    Vij, Ravi; Kumar, Shaji; Zhang, Mei-Jie; Zhong, Xiaobo; Huang, Jiaxing; Dispenzieri, Angela; Abidi, Muneer H.; Bird, Jennifer M.; Freytes, César O.; Gale, Robert Peter; Kindwall-Keller, Tamila L.; Kyle, Robert A.; Landsburg, Daniel J.; Lazarus, Hillard M.; Munker, Reinhold; Roy, Vivek; Sharma, Manish; Vogl, Dan T.; Wirk, Baldeep; Hari, Parameswaran N.

    2014-01-01

    Patients with multiple myeloma (MM), who are eligible for autologous stem cell transplantation (ASCT), typically receive a finite period of initial therapy prior to ASCT. It is not clear if patients with suboptimal (less than a partial) response to initial therapy benefit from additional alternative therapy with intent to maximize pre-transplant response. We identified 539 patients with MM who had an ASCT after having achieved less than a partial response (PR) to first line induction chemotherapy between 1995 and 2010. These patients were then divided into two groups: those who received additional salvage chemotherapy prior to ASCT (n=324) and those who had no additional salvage chemotherapy immediately prior to ASCT (n=215). Additional pre-transplant chemotherapy resulted in deepening responses in 68% (complete response in 8% and PR in 60%). On multivariate analysis there was no impact of pre-transplant salvage chemotherapy on treatment related mortality (TRM), risk for relapse, progression free or overall survival. In conclusion, for patients achieving a less than PR to initial induction therapy including with novel agent combinations, additional pre-ASCT salvage chemotherapy improved the depth of response and pre-ASCT disease status but was not associated with survival benefit. PMID:25445028

  13. Associations of Pre-transplant Prescription Narcotic Use with Clinical Complications after Kidney Transplantation

    PubMed Central

    Lentine, Krista L.; Lam, Ngan N.; Xiao, Huiling; Tuttle-Newhall, Janet E.; Axelrod, David; Brennan, Daniel C.; Dharnidharka, Vikas R.; Yuan, Hui; Nazzal, Mustafa; Zheng, Jie; Schnitzler, Mark A.

    2015-01-01

    Background Associations of narcotic use before kidney transplantation with post-transplant clinical outcomes are not well described. Methods We examined integrated national transplant registry, pharmacy records, and Medicare billing claims to follow 16,322 kidney transplant recipients, of whom 28.3% filled a narcotic prescription in the year before transplantation. Opioid analgesic fills were normalized to morphine equivalents (ME) and expressed as mg/kg exposures (approximate quartiles: 0.1– 1.7, 1.8–5.4, 5.5–23.7, and ≥23.8 mg/kg, respectively). Post-transplant cardiovascular, respiratory, neurological, accidents, substance abuse, and non-compliance events were identified using diagnosis codes on Medicare billing claims. Adjusted associations of ME level with post-transplant complications were quantified by multivariate Cox regression. Results The incidence of complications at 3 years post-transplant among those with the highest pre-transplant ME exposure compared to no use included: ventricular arrhythmias, 1.1% vs. 0.2% (p<0.001); cardiac arrest, 4.7% vs. 2.7% (p<0.05); hypotension, 14% vs. 8% (p<0.0001); hypercapnia, 1.6% vs. 0.9% (p<0.05); mental status changes, 5.3% vs. 2.7% (p<0.001); drug abuse/dependence, 7.0% vs. 1.7% (p<0.0001); alcohol abuse, 1.8% vs. 0.6% (p=0.0001); accidents, 0.9% vs. 0.3% (p<0.05); and non-compliance, 3.5% vs. 2.3% (p<0.05). In multivariate analyses, transplant recipients with the highest level of pre-transplant narcotic use had approximately 2-to-4-times the risks of post-transplant ventricular arrhythmias, mental status changes, drug abuse, alcohol abuse, and accidents compared with non-users, and 35% to 45% higher risks of cardiac arrest and hypotension. Conclusion Although associations may reflect underlying conditions or behaviors, high-level prescription narcotic use before kidney transplantation predicts increased risk of clinical complications after transplantation. PMID:25832723

  14. Pre-transplant gingival hyperplasia predicts severe cyclosporin-induced gingival overgrowth in renal transplant patients.

    PubMed

    Varga, E; Lennon, M A; Mair, L H

    1998-03-01

    The relationship between the pre-transplant periodontal status and the development of post-transplant gingival overgrowth was investigated in a longitudinal study. The periodontal condition of 35 patients was examined on 2 occasions while they were on the transplant waiting list and then at 4-6, 10-12, 16 and 20 weeks post-transplant. At each visit the plaque index, the bleeding index and a pocket index (CPITN) were measured. Dental impressions were taken of the pre- and post-transplant gingival condition and used to make stone models which were used to score the gingival overgrowth index (GOI). The patients divided into 3 distinct groups having severe (n=13), mild (n=16) or no post-transplant gingival overgrowth (n=6). Only 1 of the patients had taken cyclosporin prior to inclusion into the study. All the patients who developed severe overgrowth had evidence of gingival hyperplasia before the transplant. There was no difference in the serum cyclosporin levels between the three groups (chi2<2.28, p>0.319). Furthermore, there was no statistical difference for any of the periodontal indices. This study indicates that the hyperplastic gingival inflammatory response of some individuals appears to be potentiated by cyclosporin resulting in severe post-transplant overgrowth. In other patients the same reaction may allow the fibroblastic activity to occur to an extent where it produces a mild clinically apparent overgrowth.

  15. Synergistic photocatalytic inactivation mechanisms of bacteria by graphene sheets grafted plasmonic AgAgX (X = Cl, Br, I) composite photocatalyst under visible light irradiation.

    PubMed

    Xia, Dehua; An, Taicheng; Li, Guiying; Wang, Wanjun; Zhao, Huijun; Wong, Po Keung

    2016-08-01

    By coupling graphene sheet and plasmonic photocatalysis technologies, a series of AgAgX/RGOs (X = Cl, Br, I; RGO = reduced graphene oxide) composites were prepared and found to be efficient antimicrobial agents for water disinfection upon visible light. Attributed to the efficient charge transfer by RGO sheets, the optimum AgAgBr/0.5% RGO could completely inactivate 2 × 10(7) cfu mL(-1) of Escherichia coli within 8 min, much faster than bare AgAgBr within 35 min. The synergistic antimicrobial mechanism of AgAgBr/0.5% RGO was studied by Ag(+) ions release evaluation, radical scavengers study, and radical determination. The enhanced photocatalytic activity of irradiated AgAgBr/0.5% RGO originated from the synergistic activities of its three components including Ag, AgBr and RGO, and the proposed mechanisms contained enhanced attraction by RGO followed by two pathways: primary oxidative stress caused by plasma induced reactive species like H2O2 and bactericidal effect of released Ag(+) ions. Furthermore, characterization of E. coli cells using SEM, fluorescent microscopy, and cytoplasmic substance leakage illustrated that VL irradiated AgAgBr/0.5% RGO could not only cause metabolic dysfunction but also destroy the cell envelope and biomolecular, while irradiated Ag(+) ions play a differential bactericidal action with a limited metabolic injury and no cell-membrane damage. The present work provides an efficient water disinfection technology and also opens a new idea in studying the antimicrobial mechanism of plasmonic photocatalyst.

  16. Synergistic photocatalytic inactivation mechanisms of bacteria by graphene sheets grafted plasmonic AgAgX (X = Cl, Br, I) composite photocatalyst under visible light irradiation.

    PubMed

    Xia, Dehua; An, Taicheng; Li, Guiying; Wang, Wanjun; Zhao, Huijun; Wong, Po Keung

    2016-08-01

    By coupling graphene sheet and plasmonic photocatalysis technologies, a series of AgAgX/RGOs (X = Cl, Br, I; RGO = reduced graphene oxide) composites were prepared and found to be efficient antimicrobial agents for water disinfection upon visible light. Attributed to the efficient charge transfer by RGO sheets, the optimum AgAgBr/0.5% RGO could completely inactivate 2 × 10(7) cfu mL(-1) of Escherichia coli within 8 min, much faster than bare AgAgBr within 35 min. The synergistic antimicrobial mechanism of AgAgBr/0.5% RGO was studied by Ag(+) ions release evaluation, radical scavengers study, and radical determination. The enhanced photocatalytic activity of irradiated AgAgBr/0.5% RGO originated from the synergistic activities of its three components including Ag, AgBr and RGO, and the proposed mechanisms contained enhanced attraction by RGO followed by two pathways: primary oxidative stress caused by plasma induced reactive species like H2O2 and bactericidal effect of released Ag(+) ions. Furthermore, characterization of E. coli cells using SEM, fluorescent microscopy, and cytoplasmic substance leakage illustrated that VL irradiated AgAgBr/0.5% RGO could not only cause metabolic dysfunction but also destroy the cell envelope and biomolecular, while irradiated Ag(+) ions play a differential bactericidal action with a limited metabolic injury and no cell-membrane damage. The present work provides an efficient water disinfection technology and also opens a new idea in studying the antimicrobial mechanism of plasmonic photocatalyst. PMID:27155987

  17. Immune reactivity after high-dose irradiation

    SciTech Connect

    Gassmann, W.; Wottge, H.U.; von Kolzynski, M.; Mueller-Ruchholtz, W.

    1986-03-01

    Immune reactivity after total-body irradiation was investigated in rats using skin graft rejection as the indicator system. After sublethal irradiation with 10.5 Gy (approximately 50% lethality/6 weeks) the rejection of major histocompatibility complex allogeneic skin grafts was delayed significantly compared with nonirradiated control animals (28 versus 6.5 days). In contrast, skin grafts were rejected after 7.5 days in sublethally irradiated animals and 7 days in lethally irradiated animals if additional skin donor type alloantigens--namely, irradiated bone marrow cells--were given i.v. either simultaneously or with a delay of not more than 24 hr after the above conditioning regimen. These reactions were alloantigen-specific. They were observed in six different strain combinations with varying donors and recipients. Starting on day 2 after irradiation, i.v. injection of bone marrow gradually lost its effectivity and skin grafts were no longer rejected with uniform rapidity; skin donor marrow given on days 4 or 8 did not accelerate skin graft rejection at all. These data show that for approximately 1-2 days after high-dose total-body irradiation rats are still capable of starting a vigorous immune reaction against i.v.-injected alloantigens. The phenomenon of impaired rejection of skin grafted immediately after high-dose irradiation appears to result from the poor accessibility of skin graft alloantigens during the early postirradiation phase when vascularization of the grafted skin is insufficient.

  18. Cost-effectiveness of pretransplant sofosbuvir for preventing recurrent hepatitis C virus infection after liver transplantation.

    PubMed

    Vitale, Alessandro; Spolverato, Gaya; Burra, Patrizia; De Feo, Tullia Maria; Belli, Luca; Donato, Francesca; Baroni, Gianluca Svegliati; Marianelli, Tania; Picciotto, Antonio; Toniutto, Pierluigi; Bhoori, Sherrie; Passigato, Nicola; Lucà, Maria Grazia; Russo, Francesco Paolo; Cillo, Umberto; Fagiuoli, Stefano

    2015-09-01

    There are reports of pretransplant sofosbuvir (SOF) plus ribavirin being effective in preventing recurrent hepatitis C virus (HCV) infection after liver transplantation (LT). The aim of this study was to assess the cost-effectiveness of this strategy in the area served by the North Italy Transplant program. We retrospectively assessed the impact of HCV infection on post-LT survival in 2376 consecutive adult patients (MELD ≤ 25, unknown genotype, period 2004-2009) and the prevalence costs of conventional standard of care (SOC) antiviral therapy (pegylated interferon plus ribavirin) after LT. A Markov model was developed to compare two strategies: 12-24 weeks of SOF+ ribavirin for pre-LT anti-HCV treatment versus on-demand post-LT SOC antiviral therapy. Among the 1794 patients undergoing LT, 860 (48%) were HCV+ and 50% of them were given SOC therapy after LT (mean cost of drugs and adverse effect management = 14,421€ per patient). HCV etiology had a strong impact on post-LT survival (hazard ratio = 1.59, 95% CI = 1.22-2.09, P = 0.0007). After Monte Carlo simulation, pre-LT SOF therapy showed a median survival benefit of 1.5 quality-adjusted life years and an Incremental cost-effectiveness ratio (ICER) of 30,663€/QALY, proving cost-effective in our particular Italian scenario. The costs of SOF therapy, sustained viral response rate 12 weeks after LT, and recipient's age were the main ICER predictors at multivariate analysis. This study proposes a dynamic model based on real-life data from northern Italy for adjusting the costs of pre-LT direct-acting antiviral therapies to the actual sustained virological response reached after LT. PMID:25865602

  19. Cost-effectiveness of pretransplant sofosbuvir for preventing recurrent hepatitis C virus infection after liver transplantation.

    PubMed

    Vitale, Alessandro; Spolverato, Gaya; Burra, Patrizia; De Feo, Tullia Maria; Belli, Luca; Donato, Francesca; Baroni, Gianluca Svegliati; Marianelli, Tania; Picciotto, Antonio; Toniutto, Pierluigi; Bhoori, Sherrie; Passigato, Nicola; Lucà, Maria Grazia; Russo, Francesco Paolo; Cillo, Umberto; Fagiuoli, Stefano

    2015-09-01

    There are reports of pretransplant sofosbuvir (SOF) plus ribavirin being effective in preventing recurrent hepatitis C virus (HCV) infection after liver transplantation (LT). The aim of this study was to assess the cost-effectiveness of this strategy in the area served by the North Italy Transplant program. We retrospectively assessed the impact of HCV infection on post-LT survival in 2376 consecutive adult patients (MELD ≤ 25, unknown genotype, period 2004-2009) and the prevalence costs of conventional standard of care (SOC) antiviral therapy (pegylated interferon plus ribavirin) after LT. A Markov model was developed to compare two strategies: 12-24 weeks of SOF+ ribavirin for pre-LT anti-HCV treatment versus on-demand post-LT SOC antiviral therapy. Among the 1794 patients undergoing LT, 860 (48%) were HCV+ and 50% of them were given SOC therapy after LT (mean cost of drugs and adverse effect management = 14,421€ per patient). HCV etiology had a strong impact on post-LT survival (hazard ratio = 1.59, 95% CI = 1.22-2.09, P = 0.0007). After Monte Carlo simulation, pre-LT SOF therapy showed a median survival benefit of 1.5 quality-adjusted life years and an Incremental cost-effectiveness ratio (ICER) of 30,663€/QALY, proving cost-effective in our particular Italian scenario. The costs of SOF therapy, sustained viral response rate 12 weeks after LT, and recipient's age were the main ICER predictors at multivariate analysis. This study proposes a dynamic model based on real-life data from northern Italy for adjusting the costs of pre-LT direct-acting antiviral therapies to the actual sustained virological response reached after LT.

  20. Pre-transplant phospholipase A2 receptor autoantibody concentration is associated with clinically significant recurrence of membranous nephropathy post-kidney transplantation.

    PubMed

    Gupta, Gaurav; Fattah, Hasan; Ayalon, Rivka; Kidd, Jason; Gehr, Todd; Quintana, Luis F; Kimball, Pamela; Sadruddin, Salima; Massey, H Davis; Kumar, Dhiren; King, Anne L; Beck, Laurence H

    2016-04-01

    Previous studies that have assessed the association of pre-transplant antiphospholipase A2 receptor autoantibody (PLA2R-Ab) concentration with a recurrence of membranous nephropathy (rMN) post-kidney transplant have yielded variable results. We tested 16 consecutive transplant patients with a history of iMN for pre-transplant PLA2R-Ab. Enzyme-linked immunosorbent assay titers (Euroimmun, NJ, USA) >14 RU/mL were considered positive. A receiver operating characteristic (ROC) analysis was performed after combining data from Quintana et al. (n = 21; Transplantation February 2015) to determine a PLA2R-Ab concentration which could predict rMN. Six of 16 (37%) patients had biopsy-proven rMN at a median of 3.2 yr post-transplant. Of these, five of six (83%) had a positive PLA2R-Ab pre-transplant with a median of 82 RU/mL (range = 31-1500). The only patient who had rMN with negative PLA2R-Ab was later diagnosed with B-cell lymphoma. One hundred percent (n = 10) of patients with no evidence of rMN (median follow-up = five yr) had negative pre-transplant PLA2R-Ab. In a combined ROC analysis (n = 37), a pre-transplant PLA2R-Ab > 29 RU/mL predicted rMN with a sensitivity of 85% and a specificity of 92%. Pre-transplant PLA2R-Ab could be a useful tool for the prediction of rMN. Patients with rMN in the absence of PLA2R-Ab should be screened for occult malignancy and/or alternate antigens.

  1. Impact of pre-transplant pulmonary infection developed in horizontal laminar flow unit on the outcome of subsequent allogeneic hematopoietic stem cell transplantation

    PubMed Central

    He, Gan-Lin; Chang, Ying-Jun; Xu, Lan-Ping; Zhang, Xiao-Hui; Wang, Yu; Liu, Kai-Yan

    2016-01-01

    Background So far, there is very little literature on how pre-transplant pulmonary infection developed in horizontal laminar flow unit (HLFU) affects outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods A retrospective analysis was performed on allo-HSCT recipients who were diagnosed with pre-transplant pulmonary infection developed in HLFU between January 2012 and December 2012. Various tests were analyzed to evaluate the overall survival (OS) and pulmonary infection rate after allo-HSCT. Results Among 317 patients who received allo-HSCT from related donors, 7 cases of human leukocyte antigen (HLA)-haploidentical transplantation reported a fever, cough, and other symptoms before transplantation. Chest radiography findings showed pulmonary infection, and the C-reactive protein (CRP) level was higher than normal, which confirmed pulmonary infection (incidence rate 2.21%). The Breslow test suggested that the early survival rate was lower in the group with pre-transplant pulmonary infection than in the group without pre-transplant pulmonary infection (OS: 28.4 vs. 42.4 months; P=0.023); the early survival rate was lower in patients with a pulmonary infection accompanied by bilateral pleural effusion than in patients without pleural effusion (OS: 1.5 vs. 36.3 months; P=0.010). In the first month after transplantation, the difference in the CD4CD45RO+CD45RA- and CD4CD45RO-CD45RA+ between the groups with and without pre-transplant pulmonary infection was statistically significant (P<0.05). Patients with pre-transplant pulmonary infection who survived >3 years had a higher rate of pulmonary infection in the first 2 months after allo-HSCT than those without pre-transplant pulmonary infection [100% (5/5 patients) vs. 38.1% (118/310); χ2=5.542, P=0.019]. Conclusions Development of pre-transplant pulmonary infection in the HLFU in patients with hematological malignancies who receive HLA-haploidentical HSCT is associated with an increased risk

  2. Impact of pre-transplant pulmonary infection developed in horizontal laminar flow unit on the outcome of subsequent allogeneic hematopoietic stem cell transplantation

    PubMed Central

    He, Gan-Lin; Chang, Ying-Jun; Xu, Lan-Ping; Zhang, Xiao-Hui; Wang, Yu; Liu, Kai-Yan

    2016-01-01

    Background So far, there is very little literature on how pre-transplant pulmonary infection developed in horizontal laminar flow unit (HLFU) affects outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods A retrospective analysis was performed on allo-HSCT recipients who were diagnosed with pre-transplant pulmonary infection developed in HLFU between January 2012 and December 2012. Various tests were analyzed to evaluate the overall survival (OS) and pulmonary infection rate after allo-HSCT. Results Among 317 patients who received allo-HSCT from related donors, 7 cases of human leukocyte antigen (HLA)-haploidentical transplantation reported a fever, cough, and other symptoms before transplantation. Chest radiography findings showed pulmonary infection, and the C-reactive protein (CRP) level was higher than normal, which confirmed pulmonary infection (incidence rate 2.21%). The Breslow test suggested that the early survival rate was lower in the group with pre-transplant pulmonary infection than in the group without pre-transplant pulmonary infection (OS: 28.4 vs. 42.4 months; P=0.023); the early survival rate was lower in patients with a pulmonary infection accompanied by bilateral pleural effusion than in patients without pleural effusion (OS: 1.5 vs. 36.3 months; P=0.010). In the first month after transplantation, the difference in the CD4CD45RO+CD45RA- and CD4CD45RO-CD45RA+ between the groups with and without pre-transplant pulmonary infection was statistically significant (P<0.05). Patients with pre-transplant pulmonary infection who survived >3 years had a higher rate of pulmonary infection in the first 2 months after allo-HSCT than those without pre-transplant pulmonary infection [100% (5/5 patients) vs. 38.1% (118/310); χ2=5.542, P=0.019]. Conclusions Development of pre-transplant pulmonary infection in the HLFU in patients with hematological malignancies who receive HLA-haploidentical HSCT is associated with an increased risk

  3. Humanized Chronic Graft-versus-Host Disease in NOD-SCID il2rγ-/- (NSG) Mice with G-CSF-Mobilized Peripheral Blood Mononuclear Cells following Cyclophosphamide and Total Body Irradiation.

    PubMed

    Fujii, Hisaki; Luo, Zhi-Juan; Kim, Hye Jin; Newbigging, Susan; Gassas, Adam; Keating, Armand; Egeler, R Maarten

    2015-01-01

    Chronic graft-versus-host disease (cGvHD) is the major source of late phase morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Humanized acute GvHD (aGvHD) in vivo models using NOD-SCID il2rγ-/- (NSG) mice are well described and are important tools for investigating pathogenicity of human cells in vivo. However, there have been only few reported humanized cGvHD mouse models. We evaluated if prolonged inflammation driven by low dose G-CSF-mobilized human PBMCs (G-hPBMCs) would lead to cGvHD following cyclophosphamide (CTX) administration and total body irradiation (TBI) in NSG mice. Engraftment was assessed in peripheral blood (PB) and in specific target organs by either flow cytometry or immunohistochemistry (IHC). Tissue samples were harvested 56 days post transplantation and were evaluated by a pathologist. Some mice were kept for up to 84 days to evaluate the degree of fibrosis. Mice that received CTX at 20mg/kg did not show aGvHD with stable expansion of human CD45+ CD3+ T-cells in PB (mean; 5.8 to 23.2%). The pathology and fibrosis scores in the lung and the liver were significantly increased with aggregation of T-cells and hCD68+ macrophages. There was a correlation between liver pathology score and the percentage of hCD68+ cells, suggesting the role of macrophage in fibrogenesis in NSG mice. In order to study long-term survival, 6/9 mice who survived more than 56 days showed increased fibrosis in the lung and liver at the endpoint, which suggests the infiltrating hCD68+ macrophages may be pathogenic. It was shown that the combination of CTX and TBI with a low number of G-hPBMCs (1x106) leads to chronic lung and liver inflammation driven by a high infiltration of human macrophage and mature human T cells from the graft, resulting in fibrosis of lung and liver in NSG mice. In conclusion this model may serve as an important pre-clinical model to further current understanding of the roles of human macrophages in cGvHD.

  4. Impact of pretransplant minimal residual disease on the post-transplant outcome of pediatric acute lymphoblastic leukemia.

    PubMed

    Umeda, Katsutsugu; Hiramatsu, Hidefumi; Kawaguchi, Koji; Iwai, Atsushi; Mikami, Masamitsu; Nodomi, Seishiro; Saida, Satoshi; Heike, Toshio; Ohomori, Katsuyuki; Adachi, Souichi

    2016-08-01

    There are few reports on the clinical significance of MRD before HSCT in pediatric ALL. We retrospectively analyzed the clinical significance of FCM-based detection of MRD (FCM-MRD) before allogeneic HSCT in pediatric ALL. Of 38 pediatric patients who underwent allogeneic HSCT for the first time between 1998 and 2014, 33 patients were in CR and five patients were in non-CR. The CR group was further divided into two groups based on the pretransplant FCM-MRD level: the MRD(neg) (<0.01%; 30 patients) group and the MRD(pos) (≥0.01%; three patients) group. There were significant differences in the three-yr event-free survival rates between the CR and non-CR group, and between the MRD(neg) and MRD(pos) group. The three-yr cumulative RI in the MRD(neg) group were 27.3% ± 8.8%, whereas two of the three patients in the MRD(pos) group relapsed within one yr after HSCT. The clinical outcome of the MRD(pos) group was as poor as that of the non-CR group in pediatric ALL. Therefore, an improvement in pretransplant treatment that aims to achieve a more profound remission would contribute to reducing the risk of relapse.

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

    PubMed

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

    2009-11-15

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

  6. Electrostrictive Graft Elastomers

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  7. Radiation-induced grafting of acrylic acid onto polyethylene filaments

    NASA Astrophysics Data System (ADS)

    Kaji, K.; Okada, T.; Sakurada, I.

    Radiation-induced grafting of acrylic acid onto high density polyethylene (PE) filaments was carried out in order to raise softening temperature and impart flame retardance and hydrophilic properties. Mutual γ-irradiation method was employed for the grafting in a mixture of acrylic acid (AA), ethylene dichloride and water containing a small amount of ferrous ammonium sulfate. The rate of grafting was very low at room temperature. On the other hand, large percent grafts were obtained when the grafting was performed at an elevated temperature. Activation energy for the initial rate of grafting was found to be 17 {kcal}/{mol} between 20 and 60°C and 10 {kcal}/{mol} between 60 and 80°C. Original PE filament begins to shrink at 70°C, show maximum shrinkage of 50% at 130°C and then breaks off at 136°C. When a 34% AA graft is converted to metallic salt such as sodium and calcium, the graft filament retains its filament form even above 300°C and gives maximum shrinkage of 15%. Burning tests by a wire-netting basket method indicate that graft filaments and its metallic salts do not form melting drops upon burning and are self-extinguishing. Original PE filament shows no moisture absorption, however, that of AA-grafted PE increases with increasing graft percent. The sodium salt of 15% graft shows the same level of moisture regain as cotton. The AA-grafted PE filament and its metallic salts can be dyed with cationic dyes even at 1% graft. Tensile properties of PE filament is impaired neither by grafting nor by conversion to metallic salts.

  8. Prevalence of pre-transplant electrocardiographic abnormalities and post-transplant cardiac events in patients with liver cirrhosis

    PubMed Central

    2014-01-01

    Background Although cardiovascular disease is thouht to be common in cirrhosis, there are no systematic investigations on the prevalence of electrocardiographic (ECG) abnormalities in these patients and data on the occurrence of post-transplant cardiac events in comparison with the general population are lacking. We aimed to study the prevalence and predictors of ECG abnormalities in patients with cirrhosis undergoing liver transplantation and to define the risk of cardiac events post-transplant compared to the general population. Methods Cirrhotic patients undergoing first-time liver transplantation between 1999–2007 were retrospectively enrolled. ECGs at pre-transplant evaluation were reviewed using the Minnesota classification and compared to healthy controls. Standardized incidence ratios for post-transplant cardiac events were calculated. Results 234 patients with cirrhosis were included, 186 with an available ECG (36% with alcoholic and 24% with viral cirrhosis; mean follow-up 4 years). Cirrhotics had a prolonged QTc interval, a Q wave, abnormal QRS axis deviation, ST segment depression and a pathologic T wave more frequently compared to controls (p < 0.05 for all). Arterial hypertension, older age, cirrhosis severity and etiology were related to ECG abnormalities. Compared to the general Swedish population, patients were 14 times more likely to suffer a cardiac event post-transplant (p < 0.001). A prolonged QTc interval and Q wave were related to post-transplant cardiac events (p < 0.05 for all). Conclusions Pre-transplant ECG abnormalities are common in cirrhosis and are associated with cardiovascular risk factors and cirrhosis severity and etiology. Post-transplant cardiac events are more common than in the general population. PMID:24708568

  9. Moderator's view: Pretransplant weight loss in dialysis patients: cum grano salis.

    PubMed

    Sever, Mehmet Sukru; Zoccali, Carmine

    2015-11-01

    A high Body Mass Index (BMI) predicts delayed graft function, all cause and cardiovascular death after transplantation but such risk excess is apparently confined to patients included in studies performed before 2000. Perhaps with the exception of morbid obesity (BMI > 40), clinical outcomes in transplanted obese patients are definitely better than in listed dialysis patients who don't receive a renal transplant. Furthermore the new Scientific Registry of Transplant Recipients (SRTR) risk calculator incorporates BMI into the prediction model of the global risk for the graft's and patient's survival appropriately framing the risk of obesity in a multidimensional risk context. In the aggregate, available knowledge suggests that clinical decisions on weight loss before transplantation should be context specific. Renal transplant patients from living donors have substantial better survival in comparison to well matched dialysis patients listed for the same intervention at all BMI categories. Therefore renal transplantation in obese patients with a living donor may be prioritized. The attitude of fully informed obese patients at accepting the risk driven by transplantation, the experience of the surgical team with obese patients (including also robotic surgery) are of obvious importance. Renal transplantation should be timely considered when reasonable attempts at weight loss failed or appear overtly unrealistic. Transplantation in morbidly obese patients with BMI > 40, a category where the survival advantage of transplantation vs dialysis is probably small and still uncertain, particularly so in African-Americans, should be deferred until significant weight loss is achieved.

  10. Bone grafts in dentistry

    PubMed Central

    Kumar, Prasanna; Vinitha, Belliappa; Fathima, Ghousia

    2013-01-01

    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. PMID:23946565

  11. [Vascular graft prosthesis].

    PubMed

    Chakfé, N; Dieval, F; Thaveau, F; Rinckenbach, S; Hassani, O; Camelot, G; Durand, B; Kretz, J-G

    2004-06-01

    Performed since the 1950s, vascular grafting has opened modern era of vascular surgery. Autologous venous grafts are of first choice for revascularisation of small arteries. Synthetic grafts are mainly modelled using microporous polytetrafluoroethylene or terephtalate polyethylene. These prosthesis are mainly used for revascularization of medium and large size arteries. PMID:15220107

  12. Proton exchange membranes prepared by grafting of styrene/divinylbenzene into crosslinked PTFE membranes

    NASA Astrophysics Data System (ADS)

    Li, Jingye; Ichizuri, Shogo; Asano, Saneto; Mutou, Fumihiro; Ikeda, Shigetoshi; Iida, Minoru; Miura, Takaharu; Oshima, Akihiro; Tabata, Yoneho; Washio, Masakazu

    2005-07-01

    Thin PTFE membranes were prepared by coating the PTFE dispersion onto the aluminum films. Thus the thin crosslinked PTFE (RX-PTFE) membranes were obtained by means of electron beam irradiation above the melting temperature of PTFE under oxygen-free atmosphere. The RX-PTFE membranes were pre-irradiated and grafted by styrene with or without divinylbenzene (DVB) in liquid phase. The existence of DVB accelerated the initial grafting rate. The styrene grafted RX-PTFE membranes are white colored, on the other hand, the styrene/DVB grafted RX-PTFE membranes are colorless. The proton exchange membranes (PEMs) were obtained by sulfonating the grafted membranes using chlorosulfonic acid. The ion exchange capacity (IEC) values of the PEMs ranging from 1.5 to 2.8 meq/g were obtained. The PEMs made from the styrene/DVB grafted membranes showed higher chemical stability than those of the styrene grafted membranes under oxidative circumstance.

  13. Diagnosis and differential diagnosis of hepatic graft versus host disease (GVHD)

    PubMed Central

    Matsukuma, Karen E.; Wei, Dongguang; Sun, Kai; Ramsamooj, Rajendra

    2016-01-01

    Graft versus host disease (GVHD) is a common complication following allogeneic hematopoietic cell transplantation (HCT) that typically manifests as injury to the skin, gastrointestinal mucosa, and liver. In some cases, hepatic GVHD may be histologically indistinguishable from other disorders such as infection and drug-induced liver injury (DILI). Additionally, clinical signs and symptoms are frequently confounded by the superimposed effects of pretransplant chemoradiotherapy, immunotherapy (IT) (targeted to the underlying malignancy), GVHD prophylaxis, and infection. Thus, careful attention to and correlation with clinical findings, laboratory values, and histologic features is essential for diagnosis. This review, aimed at the practicing pathologist, will discuss current clinical and histologic criteria for GVHD, the approach to diagnosis of hepatic GVHD, and features helpful for distinguishing it from other entities in the differential diagnosis. PMID:27034810

  14. Pretransplant interferon-γ secretion by CMV-specific CD8+ T cells informs the risk of CMV replication after transplantation.

    PubMed

    Cantisán, S; Lara, R; Montejo, M; Redel, J; Rodríguez-Benot, A; Gutiérrez-Aroca, J; González-Padilla, M; Bueno, L; Rivero, A; Solana, R; Torre-Cisneros, J

    2013-03-01

    In this prospective study we analyzed pretransplant interferon-γ secretion by cytomegalovirus (CMV)-specific CD8+ T cells to assess its possible utility in determining the risk of CMV replication after solid organ transplantation. A total of 113 lung and kidney transplant patients were enrolled in the study but only 55 were evaluable. All CMV-seronegative recipients were pretransplant "nonreactive" (IFNγ <0.2 IU/mL) (11/11), whereas 30/44 (68.2%) CMV-seropositive (R+) recipients were "reactive" (IFNγ ≥0.2 IU/mL) and 14/44 (31.8%) were "nonreactive". In the R(+) "nonreactive" group, 7/14 (50%) developed posttransplant CMV replication, whereas the virus replicated only in 4/30 (13.3%) of the R(+) "reactive" patients (p = 0.021). According to the best multivariate model, pretransplant "nonreactive" recipients receiving an organ from a CMV-seropositive donor had a 10-fold increased risk of CMV replication compared to pretransplant "reactive" recipients (adjusted OR 10.49, 95% CI 1.88-58.46). This model displayed good discrimination ability (AUC 0.80) and calibration (Hosmer-Lemeshow test, p = 0.92). Negative and positive predictive values were 83.7% and 75%, respectively. The accuracy of the model was 82%. Therefore, assessment of interferon-γ secretion by cytomegalovirus (CMV)-specific CD8+ T cells prior to transplantation is useful in informing the risk of posttransplant CMV replication in solid organ transplant patients.

  15. Total lymphoid irradiation

    SciTech Connect

    Sutherland, D.E.; Ferguson, R.M.; Simmons, R.L.; Kim, T.H.; Slavin, S.; Najarian, J.S.

    1983-05-01

    Total lymphoid irradiation by itself can produce sufficient immunosuppression to prolong the survival of a variety of organ allografts in experimental animals. The degree of prolongation is dose-dependent and is limited by the toxicity that occurs with higher doses. Total lymphoid irradiation is more effective before transplantation than after, but when used after transplantation can be combined with pharmacologic immunosuppression to achieve a positive effect. In some animal models, total lymphoid irradiation induces an environment in which fully allogeneic bone marrow will engraft and induce permanent chimerism in the recipients who are then tolerant to organ allografts from the donor strain. If total lymphoid irradiation is ever to have clinical applicability on a large scale, it would seem that it would have to be under circumstances in which tolerance can be induced. However, in some animal models graft-versus-host disease occurs following bone marrow transplantation, and methods to obviate its occurrence probably will be needed if this approach is to be applied clinically. In recent years, patient and graft survival rates in renal allograft recipients treated with conventional immunosuppression have improved considerably, and thus the impetus to utilize total lymphoid irradiation for its immunosuppressive effect alone is less compelling. The future of total lymphoid irradiation probably lies in devising protocols in which maintenance immunosuppression can be eliminated, or nearly eliminated, altogether. Such protocols are effective in rodents. Whether they can be applied to clinical transplantation remains to be seen.

  16. Age at Graft Loss after Pediatric Kidney Transplantation: Exploring the High-Risk Age Window

    PubMed Central

    Van Arendonk, Kyle J.; James, Nathan T.; Boyarsky, Brian J.; Garonzik-Wang, Jacqueline M.; Orandi, Babak J.; Magee, John C.; Smith, Jodi M.; Colombani, Paul M.

    2013-01-01

    Summary Background and objective The risk of graft loss after pediatric kidney transplantation increases during late adolescence and early adulthood, but the extent to which this phenomenon affects all recipients is unknown. This study explored interactions between recipient factors and this high-risk age window, searching for a recipient phenotype that may be less susceptible during this detrimental age interval. Design, setting, participants, & measurements With use of Scientific Registry of Transplant Recipients data from 1987 to 2010, risk of graft loss across recipient age was quantified using a multivariable piecewise-constant hazard rate model with time-varying coefficients for recipient risk factors. Results Among 16,266 recipients, graft loss during ages ≥17 and <24 years was greater than that for both 3–17 years (adjusted hazard ratio [aHR], 1.61; P<0.001) and ≥24 years (aHR, 1.28; P<0.001). This finding was consistent across age at transplantation, sex, race, cause of renal disease, insurance type, pretransplant dialysis history, previous transplant, peak panel-reactive antibody (PRA), and type of induction immunosuppression. The high-risk window was seen in both living-donor and deceased-donor transplant recipients, at all levels of HLA mismatch, regardless of centers’ pediatric transplant volume, and consistently over time. The relationship between graft loss risk and donor type, PRA, transplant history, insurance type, and cause of renal disease was diminished upon entry into the high-risk window. Conclusions No recipient subgroups are exempt from the dramatic increase in graft loss during late adolescence and early adulthood, a high-risk window that modifies the relationship between typical recipient risk factors and graft loss. PMID:23430210

  17. Do Stem Cells Have an Effect When We Fat Graft?

    PubMed

    Rinker, Brian D; Vyas, Krishna S

    2016-06-01

    Fat grafting has become a widely accepted modality of soft tissue restoration and has found applications in many areas of aesthetic and reconstructive plastic surgery. Numerous claims have been made regarding the regenerative effects of fat grafting on the recipient bed. The purpose of this paper is to survey the available literature to answer the question of whether fat grafting has a positive effect on the surrounding tissues. It has been convincingly demonstrated that fat grafts contain viable adipose-derived stem cells (ASCs). The fate of these cells is determined by the microenvironment of the recipient bed, but animal studies have shown that a large fraction of ASCs survive engraftment. Numerous clinical studies have demonstrated the positive effects of fat grafting on recipient tissues. Improvement in validated scar scores as well as scar stiffness measurements have been documented after fat grafting of burn scars. Fat grafting has also been convincingly demonstrated to improve the quality of irradiated tissues, as measured by validated clinical scales and staged histology. It is ultimately unclear whether ASCs are responsible for these effects, but the circumstantial evidence is weighty. Fat grafting is effective for volumizing and improving skin quality in the setting of radiation, burns, and other scars. The observed effects are likely due to ASCs, but the evidence does not support the routine use of ASC-enriched fat grafts.

  18. Investigation of grafted ETFE-based polymer membranes as alternative electrolyte for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Aricò, A. S.; Baglio, V.; Cretı̀, P.; Di Blasi, A.; Antonucci, V.; Brunea, J.; Chapotot, A.; Bozzi, A.; Schoemans, J.

    Low cost ethylene-tetrafluoroethylene (ETFE)-based grafted membranes have been prepared by a process based on electron beam irradiation, subsequent grafting, cross-linking and sulfonation procedure. Two different grafted membranes varying by their grafting and cross-linking levels have been investigated for applications in direct methanol fuel cells (DMFCs) operating between 90 and 130 °C. DMFC assemblies based on these membranes showed cell resistance and performance values comparable to Nafion 117. Stable electrochemical performance was recorded during 1 month of cycled operation. Tailoring of grafting and cross-linking properties allows a significant reduction of methanol cross-over while maintaining suitable conductivity and performance levels.

  19. Rh antibodies against the pretransplant red cells following Rh-incompatible bone marrow transplantation.

    PubMed

    Heim, M U; Schleuning, M; Eckstein, R; Huhn, D; Siegert, W; Clemm, C; Ledderose, G; Kolb, H J; Wilmanns, W; Mempel, W

    1988-01-01

    A 22-year-old, blood group O, Rh-positive (R2r) man received bone marrow from his blood group A, Rh-negative (rr), HLA-identical sister for treatment of acute lymphocytic leukemia. The patient's pretransplantation serum contained anti-A in a low concentration; therefore, plasmapheresis was not done prior to transfusion of bone marrow. To prevent graft-versus-host disease, bone marrow was incubated with absorbed rabbit antithymocyte globulin prior to infusion, and the patient was treated with methotrexate in the posttransplantation period. After transplantation, the patient received 6 units of group O, Rh-negative (rr) packed red cells from random donors and 6 units of platelets from the marrow donor. Three months after transplantation, 0.5 percent of his red cells were still of the host's type (group O, Rh-positive), as detected by immunofluorescence technique in blood smears. Four months after transplantation, three different Rh antibodies--anti-D, -E, and -G--were detected. Since the patient received only Rh-negative red cell transfusions, it is concluded that he was immunized to his original red cells.

  20. Rh antibodies against the pretransplant red cells following Rh-incompatible bone marrow transplantation.

    PubMed

    Heim, M U; Schleuning, M; Eckstein, R; Huhn, D; Siegert, W; Clemm, C; Ledderose, G; Kolb, H J; Wilmanns, W; Mempel, W

    1988-01-01

    A 22-year-old, blood group O, Rh-positive (R2r) man received bone marrow from his blood group A, Rh-negative (rr), HLA-identical sister for treatment of acute lymphocytic leukemia. The patient's pretransplantation serum contained anti-A in a low concentration; therefore, plasmapheresis was not done prior to transfusion of bone marrow. To prevent graft-versus-host disease, bone marrow was incubated with absorbed rabbit antithymocyte globulin prior to infusion, and the patient was treated with methotrexate in the posttransplantation period. After transplantation, the patient received 6 units of group O, Rh-negative (rr) packed red cells from random donors and 6 units of platelets from the marrow donor. Three months after transplantation, 0.5 percent of his red cells were still of the host's type (group O, Rh-positive), as detected by immunofluorescence technique in blood smears. Four months after transplantation, three different Rh antibodies--anti-D, -E, and -G--were detected. Since the patient received only Rh-negative red cell transfusions, it is concluded that he was immunized to his original red cells. PMID:3130695

  1. Temperature- and pH-sensitive interpenetrating polymer networks grafted on PP: Cross-linking irradiation dose as a critical variable for the performance as vancomycin-eluting systems

    NASA Astrophysics Data System (ADS)

    Muñoz-Muñoz, Franklin; Ruiz, Juan-Carlos; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Bucio, Emilio

    2012-05-01

    This work focuses on the effect of gamma-ray radiation conditions on the stimuli-responsiveness and drug-eluting performance of polypropylene (PP) substrates grafted with interpenetrating networks of N-isopropylacrylamide (NIPAAm) and acrylic acid (AAc). PNIPAAm was cross-linked applying 10-100 kGy doses in the presence and absence of the chemical cross-linker N,N'-methylenebisacrylamide (MBAAm). Then, the net-PP-g-PNIPAAm was interpenetrated with PAAc synthesized under a 2.5 kGy dose to obtain net-PP-g-PNIPAAm-inter-net-PAAc films. The amount of grafted PNIPAAm (80%, 125% and 145% levels) and the cross-linking radiation dose (10, 40 and 70 kGy levels) strongly determine the interpenetration of PAAc, the swelling degree, the amount of vancomycin loaded and its release rate. The chemical cross-linker only caused a minor decrease in the degree of swelling. The higher the PNIPAAm grafted on PP and the lower the cross-linking radiation dose, the more the PAAc in the IPN and, consequently, the higher the vancomycin loaded through specific interactions and the more sustained the release (>8 h). The films possessing these features exhibited vancomycin release rate per surface unit suitable to prevent bacterial growth. Thus, adequate tuning of the radiation doses during grafting and cross-linking of the PNIPAAm networks may enable to achieve surface-modified materials for medical devices with an antibiofilm performance.

  2. De Novo Donor-Specific HLA Antibodies Are Associated With Rapid Loss of Graft Function Following Islet Transplantation in Type 1 Diabetes.

    PubMed

    Brooks, A M S; Carter, V; Liew, A; Marshall, H; Aldibbiat, A; Sheerin, N S; Manas, D M; White, S A; Shaw, J A M

    2015-12-01

    Outcomes after islet transplantation continue to improve but etiology of graft failure remains unclear. De novo donor-specific human leukocyte antigen (HLA) antibodies (DSA) posttransplant are increasingly recognized as a negative prognostic marker. Specific temporal associations between DSA and graft function remain undefined particularly in programs undertaking multiple sequential transplants. Impact of de novo DSA on graft function over 12 months following first islet transplant was determined prospectively in consecutive recipients taking tacrolimus/mycophenolate immunosuppression at a single center. Mixed-meal tolerance test was undertaken in parallel with HLA antibody assessment pretransplant and 1-3 months posttransplant. Sixteen participants received a total of 26 islet transplants. Five (19%) grafts were associated with de novo DSA. Five (31%) recipients were affected: three post-first transplant; two post-second transplant. DSA developed within 4 weeks of all sensitizing grafts and were associated with decreased stimulated C-peptide (median [interquartile range]) at 3 months posttransplant (DSA negative: 613(300-1090); DSA positive 106(34-235) pmol/L [p = 0.004]). De novo DSA directed against most recent islet transplant were absolutely associated with loss of graft function despite maintained immunosuppression at 12 months in the absence of a rescue nonsensitizing transplant. Alemtuzumab induction immunosuppression was associated with reduced incidence of de novo DSA formation (p = 0.03). PMID:26227015

  3. Association between Pre-Transplant Serum Malondialdehyde Levels and Survival One Year after Liver Transplantation for Hepatocellular Carcinoma

    PubMed Central

    Lorente, Leonardo; Rodriguez, Sergio T.; Sanz, Pablo; Abreu-González, Pedro; Díaz, Dácil; Moreno, Antonia M.; Borja, Elisa; Martín, María M.; Jiménez, Alejandro; Barrera, Manuel A.

    2016-01-01

    Previous studies have found higher levels of serum malondialdehyde (MDA) in hepatocellular carcinoma (HCC) patients compared to healthy controls and higher MDA concentrations in tumoral tissue of HCC patients than in non-tumoral tissue. However, the association between pre-transplant serum levels of MDA and survival in HCC patients after liver transplantation (LT) has not been described, and the aim of the present study was to determine whether such an association exists. In this observational study we measured serum MDA levels in 127 patients before LT. We found higher pre-LT serum MDA levels in 15 non-surviving than in 112 surviving patients one year after LT (p = 0.02). Exact binary logistic regression analysis revealed that pre-LT serum levels of MDA over 3.37 nmol/mL were associated with mortality after one year of LT (Odds ratio = 5.38; 95% confidence interval (CI) = from 1.580 to infinite; p = 0.007) adjusting for age of the deceased donor. The main finding of our study was that there is an association between serum MDA levels before LT for HCC and 1-year survival after LT. PMID:27058525

  4. Association between Pre-Transplant Serum Malondialdehyde Levels and Survival One Year after Liver Transplantation for Hepatocellular Carcinoma.

    PubMed

    Lorente, Leonardo; Rodriguez, Sergio T; Sanz, Pablo; Abreu-González, Pedro; Díaz, Dácil; Moreno, Antonia M; Borja, Elisa; Martín, María M; Jiménez, Alejandro; Barrera, Manuel A

    2016-04-05

    Previous studies have found higher levels of serum malondialdehyde (MDA) in hepatocellular carcinoma (HCC) patients compared to healthy controls and higher MDA concentrations in tumoral tissue of HCC patients than in non-tumoral tissue. However, the association between pre-transplant serum levels of MDA and survival in HCC patients after liver transplantation (LT) has not been described, and the aim of the present study was to determine whether such an association exists. In this observational study we measured serum MDA levels in 127 patients before LT. We found higher pre-LT serum MDA levels in 15 non-surviving than in 112 surviving patients one year after LT (p = 0.02). Exact binary logistic regression analysis revealed that pre-LT serum levels of MDA over 3.37 nmol/mL were associated with mortality after one year of LT (Odds ratio = 5.38; 95% confidence interval (CI) = from 1.580 to infinite; p = 0.007) adjusting for age of the deceased donor. The main finding of our study was that there is an association between serum MDA levels before LT for HCC and 1-year survival after LT.

  5. Analysis of cytokine production and V beta T-cell receptor subsets in irradiated recipients receiving portal or peripheral venous reconstitution with allogeneic bone marrow cells, with or without additional anti-cytokine monoclonal antibodies.

    PubMed Central

    Gorczynski, R M; Chen, Z; Zeng, H; Gorczynski, L; Terzioglu, E

    1998-01-01

    Irradiated (800 rads) AKR mice received intravenous (i.v.) reconstitution with a mixture of B10.BR T-depleted bone marrow cells and spleen cells. Only in groups of mice treated additionally with i.v. cyclophosphamide (Cy; 150 mg/kg), 24 hr before transplantation, was long-term (> 60% at 50 days) survival seen. In mice receiving only irradiation all animals died by 30 days post-transplantation. Histological changes consistent with graft-versus-host disease (GVHD) were seen in the liver of reconstituted mice at 30 days, along with an organ-specific increase in V beta 3 T-cell receptor-positive (TCR+) cells. No such increase in V beta 3 TCR+ cells was seen in the spleen from the same mice. These data are consistent with a tissue antigen-driven expansion of V beta 3 TCR+ cells associated with GVHD in the liver in this model. When we analysed cytokine production in vitro from CD3+ cells restimulated with 'host' (AKR) antigen-presenting cells (APC), we found a transition in cytokine production from preferential synthesis of type-1 cytokines [interleukin-2 (IL-2) and interferon-gamma (IFN-gamma)] at early times (day 15) post-reconstitution to increased production of type-2 cytokines [IL-4, transforming growth factor-beta (TGF-beta) and IL-10] at later times (day 30) post-reconstitution in Cy-treated recipients. Animals not receiving Cy did not show this 'switch' in cytokine production at later time points. We have observed a similar polarization in cytokine production, along with increased graft survival, in recipients of vascularized and non-vascularized allografts after portal venous (p.v.), but not i.v., pretransplant donor-specific immunization. We next studied AKR mice receiving 800 rads and subsequently reconstituted with B10.BR stem cells via the p.v. route. Again these mice showed prolonged survival (> 50% at 50 days), with polarization to IL-4, IL-10 and TGF-beta on restimulation of CD3+ cells in vitro at 30 days post-transplant and increased V beta 3 TCR+ cells

  6. Calcar bone graft

    SciTech Connect

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

    1986-01-01

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

  7. Delayed skin grafting.

    PubMed

    Ceilley, R I; Bumsted, R M; Panje, W R

    1983-04-01

    The use of skin grafts on granulating wounds is an established practice. Delaying the application of a full- or split-thickness skin graft may be an advantageous alternative method of surgical reconstruction in selected cases. Partial healing by secondary intention is useful for filling in deeper defects and usually produces a wound that is much smaller and of more normal contour than the original defect. Contraction of the graft bed is markedly influenced by location, tissue laxity, surface tension lines, motion, and wound geometry. Proper wound care, correct surgical preparation of the defect, and timing of the graft procedure are all important considerations in maximizing the overall result. Through-and-through defects and wounds produced over areas with little underlying support (eyelids and lip) often need flap reconstruction or immediate grafting to prevent undesirable functional and cosmetic results. By combining delayed healing and conventional reconstructive techniques, major tissue loss can often be restored while minimizing patient morbidity.

  8. Grafts in "closed" rhinoplasty.

    PubMed

    Scattolin, A; D'Ascanio, L

    2013-06-01

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

  9. Graft polymerization using radiation-induced peroxides and application to textile dyeing

    NASA Astrophysics Data System (ADS)

    Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Soeda, Shin

    2011-02-01

    To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

  10. Effects of solvents on the radiation grafting reaction of vinyl compounds on poly (3-hydroxybutyrate)

    NASA Astrophysics Data System (ADS)

    Torres, Maykel González; Talavera, José Rogelio Rodríguez; Muñoz, Susana Vargas; Pérez, Manuel González; Castro, Ma. Pilar. Carreón.; Cortes, Jorge Cerna; Muñoz, Rodrigo Alonso Esparza

    2015-03-01

    Vinyl Acetate was grafted onto poly (3-hydroxybutyrate) by the simultaneous gamma irradiation method using different types of solvents and in bulk (solvent free), at 10 kGy and 1.62 kGy/h dose and dose rate respectively. Subsequent complete hydrolysis allowed the conversion of grafted chains from poly (vinyl acetate) to poly (vinyl alcohol). The aim of this study is to determine the effect of solvent through the estimation of the dependence of the degree of grafting with the choice of solvent, the calculation of the degree of crystallinity, and to study the biodegradation of the products. The results showed a greater degree of grafting in bulk, while the more suitable solvent was hexane. Characterization of the grafted copolymer indicated that crystallinity percentage decreased by an increase in grafting, while the biodegradability was promoted by the increment in poly (vinyl alcohol) grafted.

  11. Radiation-grafting of acrylamide onto silicone rubber films for diclofenac delivery

    NASA Astrophysics Data System (ADS)

    Magaña, Hector; Palomino, Kenia; Cornejo-Bravo, Jose M.; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Bucio, Emilio

    2015-02-01

    This work focuses on the pre-irradiation grafting of acrylamide (AAm) onto silicone rubber films (SR) and evaluates the effect of gamma-ray radiation conditions on the grafting yield, which in turn may influence the performance of the grafted materials as components of drug-eluting devices. Pristine and modified SR were characterized using FTIR-ATR, DSC, TGA, swelling, and water contact angle analysis in order to elucidate the effects of AAm grafting onto SR. Grafted films with content in AAm ranging from 0.81% to 22.20% showed excellent cytocompatibility against fibroblasts, and capability to uptake the anti-inflammatory drug diclofenac. Amount of drug loaded directly correlated with the grafting degree of the films. Drug release studies were performed at pH 7.4 and 37 °C (physiological conditions). Most grafted films released the drug in a sustained way for at least three hours.

  12. Evaluation methods for pretransplant oncologic markers and their prognostic impacts in patient undergoing living donor liver transplantation for hepatocellular carcinoma.

    PubMed

    Shindoh, Junichi; Sugawara, Yasuhiko; Nagata, Rihito; Kaneko, Junichi; Tamura, Sumihito; Aoki, Taku; Sakamoto, Yoshihiro; Hasegawa, Kiyoshi; Tanaka, Tomohiro; Kokudo, Norihiro

    2014-04-01

    Tumor markers [alpha-fetoprotein (AFP) or des-gamma-carboxyprothrombin (DCP)] and neutrophil/lymphocyte ratio (NLR) reportedly correlate with long-term outcomes for hepatocellular carcinoma (HCC). However, no standardized method has been established for evaluating the pretransplant data. One hundred and twenty-four patients who underwent living donor liver transplantation (LDLT) were retrospectively reviewed. The best predictive parameters for tumor recurrence were maximum values for AFP or DCP and 90-day mean values for NLR, respectively, and multivariate analysis confirmed these values were correlated with tumor recurrence. However, receiver operating characteristic analysis revealed that discriminative powers were sufficient only in maximum AFP [area under the curve (AUC) 0.88, P < 0.001] and maximum DCP (AUC 0.76, P < 0.001), while mean NLR was less predictive (AUC 0.62, P = 0.20). When incorporating AFP and DCP to the Tokyo criteria (≤5 tumors with each tumor ≤ 5 cm), the presence of at least two of the following factors: (i) beyond the Tokyo criteria, (ii) AFP>250 ng/ml, and (iii) DCP > 450 mAu/ml (>450 ng/ml), was correlated with a worse 5-year disease-free survival rate (20.0% vs. 96.8%, P < 0.001) and 5-year overall survival rate (20.0% vs. 84.0%, P < 0.001). The prognosis of patients undergoing LDLT for HCC strongly relies on maximum AFP or DCP values before transplantation, while the prognostic impact of NLR is limited. PMID:24472068

  13. Heat inactivation can differentiate between IgG and IgM antibodies in the pretransplant cross match.

    PubMed

    Al-Muzairai, I A; Mansour, M; Almajed, L; Alkanderi, N; Alshatti, N; Samhan, M

    2008-09-01

    The presence of IgG antibodies in the pretransplant cross-match (XM) test results in hyperacute rejection, but IgM antibodies are inconsequential. The XM should be able to differentiate between IgG and IgM antibodies. This study evaluated 3 methods. This study was based on 500 patients for whom XM were performed between 2004 and 2006 with all 3 techniques. Two patient sera were used: normal serum and heat inactivated serum, which was prepared by incubating patient serum at 63 degrees C for 10 minutes to destroy IgM antibodies. The efficiencies of flow cytometry XM (FC-XM), dithiothreitol complement-dependent microlymphocytotoxicity (DTT/CDC-XM), and heat inactivation (HI-CDC-XM) to differentiate between IgG and IgM were evaluated by using both sera. Patients with positive XM, and negative HI-CDC-XM were reported as negative XM. During the study period, there were 70 patients with positive B-cell XM. Forty-nine became negative after HI-XM, and 21 remained positive. Only 34 cases became negative after DTT-CDC-XM and 36 remained positive. HI-CDC-XM was comparable to FC-XM; all patients testing negative with this technique experienced successful renal transplantations without hyperacute, accelerated, or acute rejection episodes. Our study showed that HI-CDC-XM was effective at exclude donor-specific IgM antibodies, a result which was comparable to FCXM to detect only IgG antibodies. HI is simple and rapid and does not involve any extra equipment or cost.

  14. Infrainguinal anastomotic arterial graft infections treated by selective graft preservation.

    PubMed Central

    Calligaro, K D; Westcott, C J; Buckley, R M; Savarese, R P; DeLaurentis, D A

    1992-01-01

    The purpose of this study was to determine whether the type of graft material and bacteria involved in an infrainguinal arterial anastomotic infection can be used as guidelines for graft preservation. Between 1972 and 1990, the authors treated 35 anastomotic infections involving a common femoral or distal artery. The graft material was Dacron in 14 patients, polytetrafluoroethylene (PTFE) in 14, and vein in 7. Of the 14 Dacron grafts, immediate graft excision was required for overwhelming infection in eight patients (bleeding in five, sepsis in three) and for an occluded graft in one patient. Three of five patients failed attempted graft preservation because of nonhealing wounds. Thus, 12 of the 14 Dacron grafts ultimately required graft excision. Of the 21 "smooth-walled" vein and PTFE grafts, 10 required immediate graft excision for occluded grafts (five PTFE, one vein) or bleeding (three PTFE, one vein). Ten of the remaining 11 (91%) patients with patent "smooth-walled" grafts, intact anastomoses, and absence of sepsis managed by graft preservation healed their wounds and maintained distal arterial perfusion. Wound cultures grew pure gram-positive cocci in 17 of 21 "smooth-walled" graft infections versus 8 of 14 Dacron graft infections. In the absence of systemic sepsis, graft preservation is the treatment of choice for gram-positive infections involving an intact anastomosis of patent PTFE and vein grafts. Regardless of the bacterial cause, the authors recommend that any infrainguinal anastomotic infection of a Dacron graft be treated by immediate excision of all infected graft material. PMID:1632705

  15. Stearyl methacrylate-grafted-chitosan nanoparticle as a nanofiller for PLA: Radiation-induced grafting and characterization

    NASA Astrophysics Data System (ADS)

    Rattanawongwiboon, Thitirat; Haema, Kamonwon; Pasanphan, Wanvimol

    2014-01-01

    This paper reports a one-pot synthesis using radiation-induced grafting technique to modify biopolymer-based chitosan nanoparticles as a nanofiller for blending with poly(lactic acid) (PLA). Hydrophobic stearyl methacrylate (SMA) was grafted onto non-irradiated chitosan (CS0) and pre-irradiated chitosan with a γ-ray dose of 40 kGy (CS40) to obtain stearyl methacrylate-grafted-chitosan nanoparticles (SMA-g-CSNPs).The effects of the pre-irradiated CS, grafting doses and SMA concentrations on degree of grafting (DG) and particle formation were studied. FT-IR and XRD were used to characterize the chemical and packing structure of SMA-g-CSNPs. The particle formulation and size of SMA-g-CSNPs were observed by TEM and AFM. The spherical core-shell SMA-g-CSNPs with the size ranging from 50 to 140 nm were successfully prepared. The SMA-g-CSNPs from CS40 has higher DG and smaller particle size when compared with CS0. The SMA-g-CSNPs are able to improve the compatibility between CS and PLA.

  16. Proximal Tibial Bone Graft

    MedlinePlus

    ... Complications Potential problems after a PTBG include infection, fracture of the proximal tibia and pain related to the procedure. Frequently Asked Questions If proximal tibial bone graft is taken from my knee, will this prevent me from being able to ...

  17. Gellan gum-graft-polyaniline--An electrical conducting biopolymer.

    PubMed

    Karthika, J S; Vishalakshi, B; Naik, Jagadish

    2016-01-01

    Grafting of polyaniline (PANI) on to gellan gum (GG) was carried out in the presence of catalytic amount of ammonium peroxydisulfate (APS) as oxidant/initiator under mild acidic conditions by microwave irradiation technique. The grafting condition was optimized by varying the microwave power, exposure time and the composition of the reaction mixture. The graft copolymer GG-g-PANI was characterized by FTIR, TGA, UV/vis, (1)H NMR and SEM techniques. The characteristic peaks at 1506, 1462, 1070 and 830 cm(-1) in the IR spectrum and signals at 7.3, 7.2, 7.1 and 4.0 δ in the (1)H NMR spectrum confirms the grafting process. The TGA data reveals GG-g-PANI to be thermally less stable than GG. The optimum grafting was observed when the reaction mixture containing 0.066 mmol APS, 0.1M aniline, 1M hydrochloric acid and 0.1g/dL GG was exposed to 80 W microwave power for 40s. The DC and AC conductivity of the GG-g-PANI were measured using the 'Two-point probe' method based on which the dielectric properties were evaluated. GG-g-PANI exhibited appreciable electrical conductivity, which increased with the extent of grafting. The results indicate threefold increase in DC conductivity of graft copolymer as compared to GG.

  18. Metabolic Serum Profiles for Patients Receiving Allogeneic Stem Cell Transplantation: The Pretransplant Profile Differs for Patients with and without Posttransplant Capillary Leak Syndrome

    PubMed Central

    Reikvam, Håkon; Grønningsæter, Ida-Sofie; Ahmed, Aymen Bushra; Hatfield, Kimberley; Bruserud, Øystein

    2015-01-01

    Allogeneic stem cell transplantation is commonly used in the treatment of younger patients with severe hematological diseases, and endothelial cells seem to be important for the development of several posttransplant complications. Capillary leak syndrome is a common early posttransplant complication where endothelial cell dysfunction probably contributes to the pathogenesis. In the present study we investigated whether the pretreatment serum metabolic profile reflects a risk of posttransplant capillary leak syndrome. We investigated the pretransplant serum levels of 766 metabolites for 80 consecutive allotransplant recipients. Patients with later capillary leak syndrome showed increased pretherapy levels of metabolites associated with endothelial dysfunction (homocitrulline, adenosine) altered renal regulation of fluid and/or electrolyte balance (betaine, methoxytyramine, and taurine) and altered vascular function (cytidine, adenosine, and methoxytyramine). Additional bioinformatical analyses showed that capillary leak syndrome was also associated with altered purine/pyrimidine metabolism (i.e., metabolites involved in vascular regulation and endothelial functions), aminoglycosylation (possibly important for endothelial cell functions), and eicosanoid metabolism (also involved in vascular regulation). Our observations are consistent with the hypothesis that the pretransplant metabolic status can be a marker for posttransplant abnormal fluid and/or electrolyte balance. PMID:26609191

  19. Effects of electron beam irradiation on binary polyamide-6 blends with metallocene copolymers

    NASA Astrophysics Data System (ADS)

    Rosales, C.; López-Quintana, S.; Gobernado-Mitre, I.; Merino, J. C.; Pastor, J. M.

    2007-12-01

    The effect of electron beam irradiation on thermal and mechanical properties, and SEM morphology of polyamide-6 (PA-6) blends with grafted copolymers was investigated. High toughness materials were obtained with ethylene-polypropylene-diene grafted copolymers without significant variations in their thermal properties and Izod impact strength at room temperature and -30 °C with the irradiation doses used.

  20. Microwave assisted synthesis of acrylamide grafted locust bean gum and its application in drug delivery.

    PubMed

    Kaity, Santanu; Isaac, Jinu; Kumar, P Mahesh; Bose, Anirbandeep; Wong, Tin Wui; Ghosh, Animesh

    2013-10-15

    Acrylamide grafted copolymer of locust bean gum was prepared by microwave irradiation using ceric ammonium nitrate as redox initiator. The grafting process was optimized in terms of irradiation time, amount of initiator and acrylamide by using constant amount of native locust bean gum. The grafted gum was characterized by Fourier transform infrared spectroscopy (FT-IR), (13)C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), X-ray diffraction study (XRD), differential scanning calorimetry (DSC), elemental analysis, contact angle, viscosity, molecular weight, swelling and biodegradability studies. The grafted gum was found to be biodegradable and non-toxic. It was further used to prepare controlled-release matrix tablet of buflomedil hydrochloride. The in vitro release profile of the tablet showed the rate controlling property of acrylamide grafted locust bean gum was similar to that of hydroxypropyl methylcellulose (HPMC-K15M).

  1. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    NASA Astrophysics Data System (ADS)

    Li, Xiaomeng; Luan, Shifang; Yang, Huawei; Shi, Hengchong; Zhao, Jie; Jin, Jing; Yin, Jinghua; Stagnaro, Paola

    2012-01-01

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  2. Swelling, ion uptake and biodegradation studies of PE film modified through radiation induced graft copolymerization

    NASA Astrophysics Data System (ADS)

    Kaur, Inderjeet; Gupta, Nitika; Kumari, Vandna

    2011-09-01

    An attempt to develop biodegradable polyethylene film grafting of mixture of hydrophilic monomers methacrylic acid (MAAc) and acrylamide (AAm) onto PE film has been carried out by preirradiation method using benzoyl peroxide as the radical initiator. Since ether linkages are susceptible to easy cleavage during degradation process, PE film was irradiated before the grafting reactions by γ-rays to introduce peroxidic linkages (PE-OO-PE) that offer sites for grafting. The effect of irradiation dose, monomer concentration, initiator concentration, temperature, time and amount of water on the grafting percent was determined. Maximum percentage of grafting of binary mixture (MAAc+AAm), (1792%) was obtained at a total concentration of binary monomer mixture=204.6×10 -2 mol/L ([MAAc]=176.5×10 -2 mol/L, [AAm]=28.1×10 -2 mol/L), [BPO]=8.3×10 -2 mol/L at 100 °C in 70 min. The grafted PE film was characterized by the Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopic (SEM) methods. Some selective properties of grafted films such as swelling studies, ion uptake and biodegradation studies have been investigated. The grafted films show good swelling in water, ion uptake studies shows promising results for desalination of brackish water and the soil burial test shows that PE film grafted with binary monomer mixture degrades up to 47% within 50 days.

  3. Thyroid transplantation developing autoimmune thyroiditis following thymectomy and irradiation.

    PubMed Central

    Ahmed, S A; Penhale, W J

    1981-01-01

    Post-irradiation transplantation of normal thyroids under the renal capsule of syngenetic thymectomized and irradiated (Tx-X) rats leads to the development of thyroiditis in the ectopic grafted thyroids. A close correlation was observed between the extent of the lesions in the grafted and recipient's own thyroid. The histopathology of both grafted and recipient thyroid was similar and was characterized by infiltration with mononuclear cells together with some plasma cells. Conversely, grafting of affected thyroids from Tx-X rats to normal animals resulted in the regression of the lesion in the graft and no evidence thyroiditis was observed in either the graft or the recipient's thyroid when these were examined 60 days post-grafting. Thyroids derived from normal animals grafted to syngenetic normal rats were found to remain healthy and intact over a 60-day period. In contrast to normal animals, Tx-X rats were unable to reject totally in transplanted allogeneic thyroids by 28 days post-grafting, suggesting that some impairment of cell-mediated immunity follows this treatment. These findings indicate that the pathological change occurring in the thyroid gland of Tx-X rats is not attributable to the local effect of irradiation of the thyroids and adds further support to the concept that the process is immunologically mediated by thyroid-specific circulating components in the absence of normal immune regulatory function. Images Fig. 1 Fig. 3 Fig. 4 PMID:6896018

  4. Mechanisms of Fat Graft Survival.

    PubMed

    Pu, Lee L Q

    2016-02-01

    Although more fat grafting procedures have been performed by plastic surgeons with the primary goal to restore soft tissue loss, the actual mechanism on how fat graft survives remains less completely understood. An established old theory on fat graft survival is still based on the cell survival theory proposed by Peer in the early 1950s. On the basis of his preliminary experimental study, he proposed that the mechanism of fat graft survival is based on established early blood circulation through anastomosis of the fat graft and host blood vessels. Recently, several investigators have demonstrated new concepts of the fat graft survival: One further advanced the old Peer cell survival theory and another based on new discovery and understanding of adipose-derived stem cells. This article serves as a scientific review on how fat graft survives after in vivo transplantation based on a number of well-conducted experimental studies. Both the graft survival and graft replacement theories on how fat graft survives are true based on the previously mentioned well-conducted experimental studies. Each theory may play a role in fat graft survival. It is possible that graft survival may be more dominant in some patients but the graft replacement may be more dominant in other patients.

  5. Grafts for Ridge Preservation

    PubMed Central

    Jamjoom, Amal; Cohen, Robert E.

    2015-01-01

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

  6. Study on biotribological properties of UHMWPE grafted with MPDSAH.

    PubMed

    Deng, Yaling; Xiong, Dangsheng; Shao, Silong

    2013-04-01

    In order to prolong the service life of artificial joints, a zwitterion monomer of MPDSAH ((3-(methacryloylamino)propyl)dimethyl (3-sulfopropyl)ammonium hydroxide) was grafted onto ultra-high molecular weight polyethylene (UHMWPE) powders to construct a brush-like structure by UV irradiation, and then the grafted UHMWPE powders were hot pressed as the bulk materials. The wettability of bulk materials surface with different monomer concentrations was analyzed. The tribological properties of modified UHMWPE bulk materials were investigated under distilled water and saline by sliding against stainless steel ball. The measurement of Fourier-transform infrared (FT-IR) spectroscopy indicates that MPDSAH is successfully grafted onto the surface of UHMWPE powders by UV irradiation. The contact angles of modified UHMWPE are decreased and the surface wettability is effectively improved. The friction coefficient of the modified sample is lower than that of untreated UHMWPE in aqueous lubricants during a long-term friction. With the increase of monomer concentration, the wear rate of grafted UHMWPE decreases gradually in distilled water. The grafting hydrophilic macromolecule polymer is helpful to form a lubricating film of water, which leads to the improvement of the lubricity of UHMWPE.

  7. Graft-versus-host disease

    MedlinePlus

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

  8. Grafting effects on vegetable quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Independent Pre-Transplant Recipient Cancer Risk Factors after Kidney Transplantation and the Utility of G-Chart Analysis for Clinical Process Control

    PubMed Central

    Kurok, Marlene; Goldis, Alon; Dreier, Maren; Kaltenborn, Alexander; Gwinner, Wilfried; Barthold, Marc; Liebeneiner, Jan; Winny, Markus; Klempnauer, Jürgen; Kleine, Moritz

    2016-01-01

    Background The aim of this study is to identify independent pre-transplant cancer risk factors after kidney transplantation and to assess the utility of G-chart analysis for clinical process control. This may contribute to the improvement of cancer surveillance processes in individual transplant centers. Patients and Methods 1655 patients after kidney transplantation at our institution with a total of 9,425 person-years of follow-up were compared retrospectively to the general German population using site-specific standardized-incidence-ratios (SIRs) of observed malignancies. Risk-adjusted multivariable Cox regression was used to identify independent pre-transplant cancer risk factors. G-chart analysis was applied to determine relevant differences in the frequency of cancer occurrences. Results Cancer incidence rates were almost three times higher as compared to the matched general population (SIR = 2.75; 95%-CI: 2.33–3.21). Significantly increased SIRs were observed for renal cell carcinoma (SIR = 22.46), post-transplant lymphoproliferative disorder (SIR = 8.36), prostate cancer (SIR = 2.22), bladder cancer (SIR = 3.24), thyroid cancer (SIR = 10.13) and melanoma (SIR = 3.08). Independent pre-transplant risk factors for cancer-free survival were age <52.3 years (p = 0.007, Hazard ratio (HR): 0.82), age >62.6 years (p = 0.001, HR: 1.29), polycystic kidney disease other than autosomal dominant polycystic kidney disease (ADPKD) (p = 0.001, HR: 0.68), high body mass index in kg/m2 (p<0.001, HR: 1.04), ADPKD (p = 0.008, HR: 1.26) and diabetic nephropathy (p = 0.004, HR = 1.51). G-chart analysis identified relevant changes in the detection rates of cancer during aftercare with no significant relation to identified risk factors for cancer-free survival (p<0.05). Conclusions Risk-adapted cancer surveillance combined with prospective G-chart analysis likely improves cancer surveillance schemes by adapting processes to identified risk factors and by using G-chart alarm

  10. Radiation induced graft copolymerization of methyl methacrylate onto chrome-tanned pig skins

    NASA Astrophysics Data System (ADS)

    Pietrucha, K.; Pȩkala, W.; Kroh, J.

    Graft copolymerization of methyl methacrylate (MMA) onto chrome-tanned pig skins was carried out by the irradiation with 60Co ?-rays. The grafted polymethyl methacrylate (PMMA) chains were isolated by acid hydrolysis of the collagen backbone in order to characterize the graft copolymers. Proof of grafting was obtained through the detection of amino acid endgroups in the isolated grafts by reaction with ninhydrin. The grafting yield of MMA in aqueous emulsion was found to be higher than that for pure MMA and MMA in acetone. The degree of grafting increases with increasing monomer concentration in emulsion and reaches maximum at radiation dose ca 15 kGy. The yield of grafting is very high - ca 90% of monomer converts into copolymer and only 10% is converted into homopolymer. The present paper reports the physical properties of chrome-tanned pig skins after graft polymerization with MMA in emulsion. Modified leathers are more resistant against water absorption and abrasion in comparison with unmodified ones. They have more uniform structure over the whole surface, greater thickness and stiffness. The results reported seem to indicate that MMA may be used in the production of shoe upper and sole leathers. The mechanism of some of the processes occuring during radiation grafting of MMA in water emulsion on tanned leathers has been also suggested and discussed.

  11. Grafting for disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. Acrylonitrile grafted to PVDF

    DOEpatents

    Yang, Jin; Eitouni, Hany Basam

    2015-03-31

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

  13. Vascular graft infections.

    PubMed

    Hasse, Barbara; Husmann, Lars; Zinkernagel, Annelies; Weber, Rainer; Lachat, Mario; Mayer, Dieter

    2013-01-01

    Vascular procedures are rarely complicated by infection, but if prosthetic vascular graft infection (PVGI) occurs, morbidity and mortality are high. Several patient-related, surgery-related and postoperative risk factors are reported, but they are not well validated. PVGI is due to bacterial colonisation of the wound and the underlying prosthetic graft, generally as a result of direct contamination during the operative procedure, mainly from the patient's skin or adjacent bowel. There is no consensus on diagnostic criteria or on the best management of PVGI. On the basis of reported clinical studies and our own experience, we advocate a surgical approach combining repeated radical local debridement, with graft preservation whenever possible or partial excision of the infected graft, depending on its condition, plus simultaneous negative-pressure wound therapy (NPWT). In addition, antimicrobial therapy is recommended, but there is no consensus on which classes of agent are adequate for the treatment of PVGI and whether certain infections may be treated by means of NPWT alone. Since staphylococci and Gram-negative rods are likely to be isolated, empirical treatment might include a penicillinase-resistant beta-lactam or a glycopeptide, plus an aminoglycoside, the latter for Gram-negative coverage and synergistic treatment of Gram-positive cocci. Additionally, empirical treatment might include rifampicin since it penetrates well into biofilms.

  14. Photoinduced Graft-Polymerization of Acrylic Acid on Polyethylene and Polypropylene Surfaces: Comparative Study Using IR-ATR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Gorbachev, A. A.; Tretinnikov, O. N.; Shkrabatovskaya, L. V.; Prikhodchenko, L. K.

    2014-11-01

    Photoinduced graft-polymerization of acrylic acid on the surface of polyethylene and polypropylene films containing a photoinitiator pre-adsorbed from a thin layer of non-de-aerated aqueous monomer solution was investigated. Data about the monomer conversion and grafting depth as functions of the UV irradiation time and polymer nature were obtained using IR-ATR spectroscopy.

  15. Reexamination of the role of Lyt-2-positive T cells in murine skin graft rejection

    SciTech Connect

    LeFrancois, L.; Bevan, M.J.

    1984-01-01

    The authors have investigated which T cell subclass defined by cytolysis with monoclonal anti-Lyt-1.2 and anti-Lyt-2.2 antibodies is required to adoptively transfer the ability to reject skin grafts. B6.Thy-1.1 spleen cells immune to graft antigens were fractionated with antibody plus C' and transferred to adult thymectomized, irradiated, bone marrow-reconstituted (ATXBM) B6.Thy-1.2 hosts that were simultaneously grafted with BALB.B skin. The authors found that when the ATXBM hosts were used 6 wk after irradiation and marrow reconstitution, both Lyt-1-depleted and Lyt-2-depleted immune spleen cells could transfer the ability to promptly reject skin grafts. However, such ATXBM recipients of Lyt-2-depleted cells that had rejected skin grafts were found to contain graft-specific CTL that were largely of host (B6.Thy-1.2) origin. When ATXBM hosts were used for the experiment 1 wk after irradiation and marrow reconstitution, no host-derived graft-specific CTL could be detected. However, graft rejection occurred in recipients of anti-Lyt-1- or anti-Lyt-2 plus C'-treated immune cells and specific CTL were generated from spleen cells of both groups. Thus, in the absence of a host-derived response, adoptively transferred immune Lyt-2+ cells, either resistant to, or that escaped from, antibody plus C' treatment, are able to expand in response to the antigenic stimulus provided by the graft. A more complete elimination of specific T cell subclasses is therefore needed to assess the relative contribution of a particular subset to the graft rejection process.

  16. Raman and histological study of the repair of surgical bone defects grafted with biphasic synthetic micro-granular HA + β- calcium triphosphate and irradiated or not with λ780 nm laser

    NASA Astrophysics Data System (ADS)

    Pinheiro, Antonio Luiz B.; Soares, Luiz Guilherme P.; Marques, Aparecida Maria C.; Aciole, Jouber Mateus S.; dos Santos, Jean N.; Silveira, Landulfo

    2014-02-01

    The treatment of bone loss due to different etiologic factors is difficult and many techniques aim to improve repair, including a wide range of biomaterials and, recently, phototherapies. This work assessed, by Raman spectroscopy and histology, the mineralization of bone defects. Forty rats divided into 4 groups each subdivided into 2 subgroups according to the time of sacrifice were used. Bone defects were made on the femur of each animal with a trephine drill. On animals of group Clot the defect was filled only by blood clot, on group Laser the defect filled with the clot was further irradiated. On animals of groups Biomaterial and Laser + Biomaterial the defect was filled by biomaterial and the last one was further irradiated (λ780 nm, 70 mW, Φ ~ 0.4 cm2, 20 J/cm2-session, 140 J/cm2-treatment). At both 15th and 30th days following sacrifice, samples were taken and analyzed by Raman spectroscopy and light microscopy. Raman peaks of inorganic and organic contents and a more advanced stage of repair were seen on group Laser + Biomaterial. It is concluded that the use of Laser phototherapy associated to biomaterial was effective to improve the repair of bone defects.

  17. Accelerated adhesion of grafted skins by laser-induced stress wave-based gene transfer of hepatocyte growth factor

    NASA Astrophysics Data System (ADS)

    Aizawa, Kazuya; Sato, Shunichi; Saitoh, Daizoh; Tsuda, Hitoshi; Ashida, Hiroshi; Obara, Minoru

    2009-02-01

    In our previous study, we delivered plasmid DNA coding for human hepatocyto growth factor (hHGF) to rat skin grafts based on laser-induced stress wave (LISW), by which production of CD31-positive cells in the grafted skins was found to be enhanced, suggesting improved angiogenesis. In this study, we validated the efficacy of this method to accelerate adhesion of grafted skins; reperfusion and reepithelialization in the grafted skins were examined. As a graft, dorsal skin of a rat was exsected and its subcutaneous fat was removed. Plasmid DNA expression vector for hHGF was injected into the graft; on its back surface a laser target with a transparent sheet for plasma confinement was placed, and irradiated with three nanosecond laser pulses at a laser fluence of 1.2 J/cm2 (532 nm; spot diameter, 3 mm) to generate LISWs. After the application of LISWs, the graft was transplanted onto its donor site. We evaluated blood flow by laser Doppler imaging and analyzed reepithelialization based on immunohistochemistry as a function of postgrafting time. It was found that both reperfusion and reepithelialization were significantly enhanced for the grafts with gene transfection than for normal grafts; reepithelialization was completed within 7 days after transplantation with the transfected grafts. These findings demonstrate that adhesion of grafted skins can be accelerated by delivering HGF gene to the grafts based on LISWs.

  18. Skin allografts in lethally irradiated animals repopulated with syngeneic hemopoietic cells

    SciTech Connect

    Schwadron, R.B.

    1983-01-01

    Total body irradiation and repopulation with syngeneic hemopoietic cells can be used to induce tolerance to major histocompatibility complex (MHC) mismatched heart and kidney grafts in rats and mice. However, this protocol does not work for MHC mismatched skin grafts in rats or mice. Furthermore, LEW rats that accept WF cardiac allografts after irradiation and repopulation reject subsequent WF skin grafts. Treatment of skin allograft donors with methotrexate prior to grafting onto irradiated and reconstituted mice resulted in doubling of the mean survival time. Analysis of which antigens provoked skin graft rejection by irradiation and reconstituted animals revealed the importance of I region antigens. Cardiac allograft acceptance by irradiated and reconstituted animals is mediated by suppressor cells found in the spleen. Adoptively tolerant LEW rats accepted WF skin grafts in 50% of grafted animals. Analysis of this phenomenon revealed that the adoptive transfer procedure itself was important in achieving skin allograft acceptance by these animals. In general, it seems that the lack of ability of irradiated and reconstituted animals to accept fully MHC disparate skin grafts results from the inability of these animals to suppress lymph node effector cells against I region antigen seen on highly immunogenic allogeneic Langerhans cells in the skin.

  19. Standardization of procedures for ectopic marrow grafting. II. Influence on recipients of radiation dose and field size

    SciTech Connect

    Molineux, G.; Schofield, R.; Hendry, J.H.; Testa, N.G.

    1987-07-01

    The ectopic implantation of mouse marrow to the kidney capsule offers considerable scope as an assay of the hemopoietic microenvironment. Our previous work has shown that whole-body irradiation of the graft recipient prior to implantation results in superior ossicle formation in the kidney of the host. Here we report that a range of irradiation doses over a 4-Gy threshold are equivalent with respect to conditioning the graft recipient. We also show that two distinct and separable influences affect graft growth in the irradiated recipient, namely, a local effect brought about in the irradiated kidney (and restricted to it) and secondly, a systemic effect resulting from irradiation of sites other than the kidney, which nevertheless affects ossicle growth in the shielded renal capsule.

  20. Siloxane-grafted membranes

    DOEpatents

    Friesen, Dwayne T.; Obligin, Alan S.

    1989-01-01

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

  1. Siloxane-grafted membranes

    DOEpatents

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

    1989-10-31

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

  2. Total lymphoid irradiation and discordant cardiac xenografts

    SciTech Connect

    Kaplan, E.; Dresdale, A.R.; Diehl, J.T.; Katzen, N.A.; Aronovitz, M.J.; Konstam, M.A.; Payne, D.D.; Cleveland, R.J. )

    1990-01-01

    Total lymphoid irradiation can prolong concordant cardiac xenografts. The effects of total lymphoid irradiation in a discordant xenograft model (guinea pig to rat) were studied with and without adjuvant pharmacologic immunosuppression. Inbred Lewis rats were randomly allocated to one of four groups. Group 1 (n = 6) served as a control group and rats received no immunosuppression. Group 2 (n = 5) received triple-drug therapy that consisted of intraperitoneal azathioprine (2 mg/kg), cyclosporine (20 mg/kg), and methylprednisolone (1 mg/kg) for 1 week before transplantation. Group 3 animals (n = 5) received 15 Gy of total lymphoid irradiation in 12 divided doses over a 3-week period. Group 4 (n = 6) received both triple-drug therapy and total lymphoid irradiation as described for groups 2 and 3. Complement-dependent cytotoxicity assay was performed to determine if a correlation between complement-dependent cytotoxicity and rejection-free interval existed. Rejection was defined as cessation of graft pulsation and was confirmed by histologic test results. Only groups 1 and 2 showed a difference in survival (group 1, 6.9 +/- 1.0 minutes; group 2, 14.2 +/- 2.7 minutes, p = 0.02). Although total lymphoid irradiation did decrease complement-dependent cytotoxicity, linear regression revealed no correlation between complement-dependent cytotoxicity and graft survival (coefficient of correlation, 0.30). Unlike concordant cardiac xenografts, total lymphoid irradiation with or without triple-drug therapy does not prolong graft survival.

  3. The tolerance of skin grafts to postoperative radiation therapy in patients with soft-tissue sarcoma

    SciTech Connect

    Lawrence, W.T.; Zabell, A.; McDonald, H.D. )

    1986-03-01

    During the last ten years at the National Cancer Institute, 11 patients have received 12 courses of postoperative adjuvant radiation therapy to skin grafts used for wound closure after the resection of soft-tissue sarcomas. The intervals between grafting and the initiation of radiation ranged between 3 and 20 weeks, and 4 patients received chemotherapy at the same time as their radiation. Ten of the 12 irradiated grafts remained intact after the completion of therapy. One graft had several small persistently ulcerated areas that required no further surgical treatment, and one graft required a musculocutaneous flap for reconstruction of a persistent large ulcer. Acute radiation effects on the grafted skin sometimes developed at slightly lower doses than usually seen with normal skin, but these acute effects necessitated a break in therapy on only five occasions. Concurrent chemotherapy and a relatively short interval between grafting and the initiation of radiation seemed to contribute to more severe radiation reactions. This experience indicates that postoperative adjuvant radiation therapy can be delivered to skin grafted areas without undue fear of complications, especially if the graft is allowed to heal adequately prior to initiating therapy and if chemotherapy is not given in conjunction with radiation.

  4. Radiation-induced graft polymerization of amphiphilic monomers with different polymerization characteristics onto hydrophobic polysilane

    NASA Astrophysics Data System (ADS)

    Tanaka, Hidenori; Iwasaki, Isao; Kunai, Yuichiro; Sato, Nobuhiro; Matsuyama, Tomochika

    2011-08-01

    The structures of poly(methyl-n-propylsilane) (PMPrS) amphiphilically modified through γ-ray-induced graft polymerization were investigated with 1H NMR measurement. By the use of methyl methacrylate (MMA) or diethyl fumarate (DEF) as monomers for the graft polymerization, grafting yield rose with increasing total absorption dose and monomer concentrations, but decreased with increasing dose rate. This result means that grafting yield of modified PMPrS can be controlled by changing irradiation conditions. However, the number of PMMA or PDEF graft chains per PMPrS chain was estimated to be less than 1.0 by analysis of 1H NMR spectra, and this value was lower than that we had expected. To improve graft density, maleic anhydride (MAH), which is known as a non-homopolymerizable monomer in radical polymerization, was used as a monomer for grafting. As a result, high density grafting (one MAH unit for 4.2 silicon atoms) was attained. It demonstrates that the structure of γ-ray-modified polysilane strongly depends on the polymerization characteristics of grafted monomers.

  5. Radiation grafting of acrylic and methacrylic acid to cellulose fibers to impart high water sorbency

    SciTech Connect

    Zahran, A.H.; Williams, J.L.; Stannett, V.T.

    1980-04-01

    Acrylic and methacrylic acids have been directly grafted to rayon and cotton using the preirradiation technique with /sup 60/ Co gamma rays. The rate of grafting increased with increasing temperature and monomer concentration, as did the final degree of grafting. The amount and rate of grafting also increased with the total irradiation dose but tended to level off at higher doses, in agreement with the leveling off of the radical content reported previously. Methacrylic acid grafted more and faster than acrylic acid to both rayon and cotton. Methacrylic acid grafted more with rayon than cotton, but acrylic acid gave somewhat similar yields with both fibers. The water abosrbency of the grafted fibers depended strongly on their posttreatment. Decrystallizing with 70% zinc chloride or with hot sodium hydroxidy developed supersorbency. The two treatments in succession, respectively, gave the highest values. Metacrylic acid brought about less sorbency than the corrsponding acrylic acid grafts. Useful levels of grafting and supersorbency could be readily and practically achieved by the methods described.

  6. Radiation-induced and RAFT-mediated grafting of poly(hydroxyethyl methacrylate) (PHEMA) from cellulose surfaces

    NASA Astrophysics Data System (ADS)

    Kodama, Yasko; Barsbay, Murat; Güven, Olgun

    2014-01-01

    This paper presents the results of RAFT mediated free-radical graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) onto cellulose fibers in a "grafting-from" approach under γ-irradiation. The effects of absorbed dose and monomer concentration on the graft ratios were investigated at different monomer (HEMA) to RAFT agent (cumyl dithiobenzoate, CDB) ratios. Cellulose-g-PHEMA copolymers with various graft ratios up to 92% (w/w) have been synthesized. The synthesized copolymers were characterized by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy, elemental analysis and scanning electron microscopy. The results of various techniques confirmed the existence of PHEMA in the copolymer composition.

  7. [Bone grafts in orthopedic surgery].

    PubMed

    Zárate-Kalfópulos, Barón; Reyes-Sánchez, Alejandro

    2006-01-01

    In orthopedic surgery the demand for the use of bone grafts increases daily because of the increasing quantity and complexity of surgical procedures. At present, the gold standard is the autologous bone graft but the failure rate, morbidity of the donor site and limited availability have stimulated a proliferation for finding materials that work as bone graft substitutes. In order to have good success, we must know the different properties of these choices and the environment where the graft is going to be used. As bone graft substitutes and growth factors become clinical realities, a new gold standard will be defined. Tissue engineering and gene therapy techniques have the objective to create an optimum bone graft substitute with a combination of substances with properties of osteconduction, osteogenesis and osteoinduction. PMID:16875525

  8. [Bone grafts in orthopedic surgery].

    PubMed

    Zárate-Kalfópulos, Barón; Reyes-Sánchez, Alejandro

    2006-01-01

    In orthopedic surgery the demand for the use of bone grafts increases daily because of the increasing quantity and complexity of surgical procedures. At present, the gold standard is the autologous bone graft but the failure rate, morbidity of the donor site and limited availability have stimulated a proliferation for finding materials that work as bone graft substitutes. In order to have good success, we must know the different properties of these choices and the environment where the graft is going to be used. As bone graft substitutes and growth factors become clinical realities, a new gold standard will be defined. Tissue engineering and gene therapy techniques have the objective to create an optimum bone graft substitute with a combination of substances with properties of osteconduction, osteogenesis and osteoinduction.

  9. Radiation-induced graft polymerization of chitosan onto poly(3-hydroxybutyrate).

    PubMed

    Torres, Maykel González; Muñoz, Susana Vargas; Rosales, Silvia G Solís; Carreón-Castro, Ma del Pilar; Muñoz, Rodrigo Alonso Esparza; González, Roberto Olayo; González, Miriam Rocío Estévez; Talavera, Rogelio Rodríguez

    2015-11-20

    Chitosan is among the most studied biopolymers and offers important advantages, such as biodegradability, biocompatibility and nontoxicity. In this study, this polysaccharide was grafted onto poly(3-hydroxybutyrate) using the simultaneous gamma-irradiation-initiated polymerization method. The polyester was immersed in diverse solvents, which allowed the preparation of graft copolymers with different yields and crystallinities. A successful synthesis and the estimation of the degree of crystallinity were verified by spectroscopic and calorimetric techniques. The most suitable method was found to be the thermoanalytical approach because it displayed a linear relationship between the degree of crystallinity and the increasing degree of grafting. The results also indicated that the lowest degree of grafting was seen for acetic acid (14.27%), while the highest degree corresponded to ethyl acetate (32.11%). The mechanism of grafting was proposed on the basis of the experimental results.

  10. Singly and binary grafted poly(vinyl chloride) urinary catheters that elute ciprofloxacin and prevent bacteria adhesion.

    PubMed

    Islas, Luisa; Alvarez-Lorenzo, Carmen; Magariños, Beatriz; Concheiro, Angel; del Castillo, Luis Felipe; Burillo, Guillermina

    2015-07-01

    Acrylic acid (AAc) and poly(ethylene glycol) methacrylate (PEGMA) were singly and dually grafted onto poly(vinyl chloride) (PVC) urinary catheters with the aim of preventing biofouling by endowing the catheters with the ability to load and release antimicrobial agents and to avoid bacteria adhesion. The polymers were grafted applying an oxidative pre-irradiation ((60)Co source) method in two steps. Grafting percentage and kinetics were evaluated by varying the absorbed pre-irradiation dose, reaction time, monomer concentration, and reaction temperature. Catheters with grafting percentages ranging from 8 to 207% were characterized regarding thermal stability, surface hydrophilicity, mechanical properties, swelling, and lubricity. The modified catheters proved to have better compatibility with fibroblast cells than PVC after long exposure times. Furthermore, grafted catheters were able to load ciprofloxacin and sustained its release in urine medium for several hours. Ciprofloxacin-loaded catheters inhibited the growth of Escherichia coli and Staphylococcus aureus in the catheter surroundings and prevented bacteria adhesion.

  11. Cotton fabric modification for imparting high water and oil repellency using perfluoroalkyl phosphate acrylate via γ-ray-induced grafting

    NASA Astrophysics Data System (ADS)

    Miao, Hui; Bao, Fenfen; Cheng, Liangliang; Shi, Wenfang

    2010-07-01

    The perfluoroalkyl phosphate acrylates were grafted onto a cotton fabric via γ-ray irradiation to improve the hydrophobic and oleophobic properties. The change in chemical structure of grafted cotton fabric was detected by the Fourier transform infrared spectroscopy and the X-ray photoelectron spectroscopy. The contact angles for water and sunflower oil were determined to be over 150° and 140°, respectively, after irradiated with a dose range of 471-5664 Gy. The flame retardancy of the fabric with a grafting ratio of over 13.0 wt% was improved, reaching to 24 compared with 18 of which before grafted, according to the limiting oxygen index measurement. The microstructure of the fabric before and after grafted was observed by the scanning electron microscope.

  12. Radiation grafting of oligo(ethylene glycol) ethyl ether methacrylate on polypropylene

    NASA Astrophysics Data System (ADS)

    Komasa, Justyna; Miłek, Andrzej; Ulański, Piotr; Rosiak, Janusz M.

    2014-01-01

    Oligo(ethylene glycol) ethyl ether methacrylate (OEGMA) can be grafted onto polypropylene (PP) films by post-irradiation grafting, forming a thermosensitive polymer layer, as indicated by FT-IR and contact angle measurements. In the first step, PP foils are irradiated by electron beam (5.5 kGy/min, up to 300 kGy) in the presence of air. Subsequently, the irradiated foils react with the monomer in oxygen-free solutions in isopropanol (up to 2 M of monomer) at 70 °C. Degree of grafting of OEGMA can be controlled by proper selection of absorbed dose, monomer concentration and reaction time. This work is a part of a broader project on thermosensitive materials facilitating cell growth and detachment for optimizing cell layer engineering techniques in the treatment of burn wounds.

  13. Radiation grafting of maleic anhydride onto polypropylene in solid state via ultrafine blend

    NASA Astrophysics Data System (ADS)

    Tan, Xiumin

    2014-05-01

    A novel method to prepare maleic anhydride grafting onto poly (propylene) (PP-g-MAH) was described. It was performed by γ-irradiation in solid state via ultrafine blend in the absence of any initiator and the grafting mechanism was proposed based on the experimental results. First, ultrafine blend of MAH and PP was prepared through ultrasonic initiation in melt state and then cooled rapidly. Second, the blend was radiated by γ-irradiation in the circumstance of atmosphere. Effects of irradiation dose and MAH concentration on the amount of grafted MAH were investigated. Compared with the conventional solid-state radiation grafting method, PP-g-MAH obtained via this method shows a higher graft rate of MAH. This novel method also has the advantages of solventless, energy efficient, low cost and simple operation. Furthermore, it is very easy to get purified products. The molecular structures of grafted copolymer were characterized by Fourier-transform infrared spectroscopy. Differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscope were used to determine the degree of crystallinity and crystalline structure.

  14. Submicroscopic pores grafted using the residual sites produced by swift heavy ions

    NASA Astrophysics Data System (ADS)

    Mazzei, R.; Betz, N.; Bermúdez, G. García; Massa, G.; Smolko, E.

    2005-07-01

    To produce nuclear track membranes (NTM) with submicroscopic pores poly(vinylidene difluoride) (PVDF) foils were irradiated with Cl, Ag and Pb ions. Then they were chemically etched for different times and grafted with acrylic acid. The grafting yields were determined by weight measurements as a function of ion fluence, etching time and also analysed using Fourier transform infrared spectroscopy. Both measurements suggest that the acrylic acid was grafted on the pore wall of the NTM using the active sites left by the ion beam.

  15. Rapid, facile microwave-assisted synthesis of xanthan gum grafted polyaniline for chemical sensor.

    PubMed

    Pandey, Sadanand; Ramontja, James

    2016-08-01

    Grafting method, through microwave radiation procedure is extremely productive in terms of time consumption, cost effectiveness and environmental friendliness. In this study, conductive and thermally stable composite (mwXG-g-PANi) was synthesized by grafting of aniline (ANi) on to xanthan gum (XG) using catalytic weight of initiator, ammonium peroxydisulfate in the process of microwave irradiation in an aqueous medium. The synthesis of mwXG-g-PANi were confirm by FTIR, XRD, TGA, and SEM. The influence of altering the microwave power, exposure time of microwave, concentration of monomer and the amount of initiator of graft polymerization were studied over the grafting parameters, for example, grafting percentage (%G) and grafting efficiency (%E). The maximum %G and %E achieved was 172 and 74.13 respectively. The outcome demonstrates that the microwave irradiation strategy can increase the reaction rate by 72 times over the conventional method. Electrical conductivity of XG and mwXG-g-PANi composite film was performed. The fabricated grafted sample film were then examined for the chemical sensor. The mwXG-g-PANi, effectively integrated and handled, are NH3 sensitive and exhibit a rapid sensing in presence of NH3 vapor. Chemiresistive NH3 sensors with superior room temperature sensing performance were produced with sensor response of 905 at 1ppb and 90% recovery within few second. PMID:27118045

  16. Antimicrobial Graft Copolymer Gels.

    PubMed

    Harvey, Amanda C; Madsen, Jeppe; Douglas, C W Ian; MacNeil, Sheila; Armes, Steven P

    2016-08-01

    In view of the growing worldwide rise in microbial resistance, there is considerable interest in designing new antimicrobial copolymers. The aim of the current study was to investigate the relationship between antimicrobial activity and copolymer composition/architecture to gain a better understanding of their mechanism of action. Specifically, the antibacterial activity of several copolymers based on 2-(methacryloyloxy)ethyl phosphorylcholine [MPC] and 2-hydroxypropyl methacrylate (HPMA) toward Staphylococcus aureus was examined. Both block and graft copolymers were synthesized using either atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization and characterized via (1)H NMR, gel permeation chromatography, rheology, and surface tensiometry. Antimicrobial activity was assessed using a range of well-known assays, including direct contact, live/dead staining, and the release of lactate dehydrogenase (LDH), while transmission electron microscopy was used to study the morphology of the bacteria before and after the addition of various copolymers. As expected, PMPC homopolymer was biocompatible but possessed no discernible antimicrobial activity. PMPC-based graft copolymers comprising PHPMA side chains (i.e. PMPC-g-PHPMA) significantly reduced both bacterial growth and viability. In contrast, a PMPC-PHPMA diblock copolymer comprising a PMPC stabilizer block and a hydrophobic core-forming PHPMA block did not exhibit any antimicrobial activity, although it did form a biocompatible worm gel. Surface tensiometry studies and LDH release assays suggest that the PMPC-g-PHPMA graft copolymer exhibits surfactant-like activity. Thus, the observed antimicrobial activity is likely to be the result of the weakly hydrophobic PHPMA chains penetrating (and hence rupturing) the bacterial membrane. PMID:27409712

  17. Radiation-grafted, chemically modified membranes part I - Synthesis of a selective aluminum material

    NASA Astrophysics Data System (ADS)

    Bazante-Yamaguishi, Renata; Moura, Eduardo; Manzoli, José E.; Geraldo, Aurea B. C.

    2014-01-01

    Polymeric membranes were styrene grafted by irradiation methods and the obtained material was chemically modified to become aluminum selective. For this purpose, polymeric substrates of PVC (polyvinyl chloride) and PP (polypropylene) were styrene grafted mutually by gamma and electron beam irradiation. The modification process includes three basic reaction paths: Friedel-Crafts acylation, 2-methylanisole coupling and a final oxidation to achieve aluminum selectivity. Although this specific chemical modification in derivatives of polystyrene is not new, the new challenge is to obtain a selective material where original membrane characteristics (physical shape and mechanical resistance) are minimally conserved after such an aggressive treatment.

  18. Listeria monocytogenes Endovascular Graft Infection

    PubMed Central

    Heysell, Scott K.; Hughes, Molly A.

    2016-01-01

    Although best managed by surgical resection, we present a case of Listeria monocytogenes endovascular graft infection alternatively treated with graft retention and antibiotic induction followed by a lifelong suppressive course. The epidemiological, pathological, and clinical features of this unique entity are reviewed. PMID:26835477

  19. Grafting effects on vegetable quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Polyether/Polyester Graft Copolymers

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  1. [Stent Grafting for Aortic Dissection].

    PubMed

    Uchida, Naomichi

    2016-07-01

    The purpose of stent graft for aortic dissection is to terminate antegrade blood flow into the false lumen through primary entry. Early intervention for primary entry makes excellent aortic remodeling and emergent stent grafting for complicated acute type B aortic dissection is supported as a class I. On the other hand stent grafting for chronic aortic dissection is controversial. Early stent grafting is considered with in 6 months after on-set if the diameter of the descending aorta is more than 40 mm. Additional interventions for residual false lumen on the downstream aorta are still required. Stent graft for re-entry, candy-plug technique, and double stenting, other effective re-interventions were reported. Best treatment on the basis of each anatomical and physical characteristics should be selected in each institution. Frozen elephant trunk is alternative procedure for aortic dissection without the need to take account of proximal anatomical limitation and effective for acute type A aortic dissection. PMID:27440026

  2. Graft-Versus-Host Disease and Graft-Versus-Tumor Effects After Allogeneic Hematopoietic Cell Transplantation

    PubMed Central

    Storb, Rainer; Gyurkocza, Boglarka; Storer, Barry E.; Sorror, Mohamed L.; Blume, Karl; Niederwieser, Dietger; Chauncey, Thomas R.; Pulsipher, Michael A.; Petersen, Finn B.; Sahebi, Firoozeh; Agura, Edward D.; Hari, Parameswaran; Bruno, Benedetto; McSweeney, Peter A.; Maris, Michael B.; Maziarz, Richard T.; Langston, Amelia A.; Bethge, Wolfgang; Vindeløv, Lars; Franke, Georg-Nikolaus; Laport, Ginna G.; Yeager, Andrew M.; Hübel, Kai; Deeg, H. Joachim; Georges, George E.; Flowers, Mary E.D.; Martin, Paul J.; Mielcarek, Marco; Woolfrey, Ann E.; Maloney, David G.; Sandmaier, Brenda M.

    2013-01-01

    Purpose We designed a minimal-intensity conditioning regimen for allogeneic hematopoietic cell transplantation (HCT) in patients with advanced hematologic malignancies unable to tolerate high-intensity regimens because of age, serious comorbidities, or previous high-dose HCT. The regimen allows the purest assessment of graft-versus-tumor (GVT) effects apart from conditioning and graft-versus-host disease (GVHD) not augmented by regimen-related toxicities. Patients and Methods Patients received low-dose total-body irradiation ± fludarabine before HCT from HLA-matched related (n = 611) or unrelated (n = 481) donors, followed by mycophenolate mofetil and a calcineurin inhibitor to aid engraftment and control GVHD. Median patient age was 56 years (range, 7 to 75 years). Forty-five percent of patients had comorbidity scores of ≥ 3. Median follow-up time was 5 years (range, 0.6 to 12.7 years). Results Depending on disease risk, comorbidities, and GVHD, lasting remissions were seen in 45% to 75% of patients, and 5-year survival ranged from 25% to 60%. At 5 years, the nonrelapse mortality (NRM) rate was 24%, and the relapse mortality rate was 34.5%. Most NRM was a result of GVHD. The most significant factors associated with GVHD-associated NRM were serious comorbidities and grafts from unrelated donors. Most relapses occurred early while the immune system was compromised. GVT effects were comparable after unrelated and related grafts. Chronic GVHD, but not acute GVHD, further increased GVT effects. The potential benefit associated with chronic GVHD was outweighed by increased NRM. Conclusion Allogeneic HCT relying on GVT effects is feasible and results in cures of an appreciable number of malignancies. Improved results could come from methods that control progression of malignancy early after HCT and effectively prevent GVHD. PMID:23478054

  3. Clinical value of pre-transplant minimal residual disease in childhood lymphoblastic leukaemia: the results of the French minimal residual disease-guided protocol.

    PubMed

    Gandemer, Virginie; Pochon, Cécile; Oger, Emmanuel; Dalle, Jean-Hugues H; Michel, Gérard; Schmitt, Claudine; de Berranger, Eva; Galambrun, Claire; Cavé, Hélène; Cayuela, Jean-Michel; Grardel, Nathalie; Macintyre, Elizabeth; Margueritte, Geneviève; Méchinaud, Françoise; Rorhlich, Pierre; Lutz, Patrick; Demeocq, François; Schneider, Pascale; Plantaz, Dominique; Poirée, Marilyne; Bordigoni, Pierre

    2014-05-01

    Minimal residual disease (MRD) is a major predictive factor of the cure rate of acute lymphoblastic leukaemia (ALL). Haematopoietic cell transplantation is a treatment option for patients at high risk of relapse. Between 2005 and 2008, we conducted a prospective study evaluating the feasibility and efficacy of the reduction of immunosuppressive medication shortly after a non-ex vivo T depleted myeloablative transplantation. Immunoglobulin (Ig)H/T-cell receptor MRD 30 d before transplant could be obtained in 122 of the 133 cases of high-risk paediatric ALL enrolled. There were no significant demographic differences except remission status (first or second complete remission) between the 95 children with MRD <10(-3) and the 27 with MRD ≥10(-3) . Multivariate analysis identified sex match and MRD as being significantly associated with 5-year survival. MRD ≥10(-3) compromised the 5-year cumulative incidence of relapse (43·6 vs. 16·7%). Complete remission status and stem cell source did not modify the relationship between MRD and prognosis. Thus, pre-transplant MRD is still a major predictor of outcome for ALL. The MRD-guided strategy resulted in survival for 72·3% of patients with MRD<10(-3) and 40·4% of those with MRD ≥10(-3).

  4. Graft polymerization of acrylic acid and methacrylic acid onto poly(vinylidene fluoride) powder in presence of metallic salt and sulfuric acid

    NASA Astrophysics Data System (ADS)

    Deng, Bo; Yu, Yang; Zhang, Bowu; Yang, Xuanxuan; Li, Linfan; Yu, Ming; Li, Jingye

    2011-02-01

    Poly(vinylidene fluoride) (PVDF) powder was grafted with acrylic acid (AAc) or methacrylic acid (MAA) by the pre-irradiation induced graft polymerization technique. The presence of graft chains was proven by FT-IR spectroscopy. The degree of grafting (DG) was calculated by the acid-base back titration method. The synergistic effect of acid and Mohr's salt on the grafting kinetics was examined. The results indicated that adding sulfuric acid and Mohr's salt simultaneously in AAc or MAA solutions led to a strong enhancement in the degree of grafting. The grafted PVDF powder was cast into microfiltration (MF) membranes using the phase inversion method and some properties of the obtained MF membranes were characterized.

  5. Irradiated mandibular autografts

    SciTech Connect

    Hamaker, R.C.; Singer, M.I.; Shockley, W.W.; Pugh, N.; Shidnia, H.

    1983-09-15

    The cosmetic and functional disability associated with mandibular resection has been a major problem to the patient with direct invasion of the mandible by oral cancer. Marginal resections with combined postoperative radiation therapy have frequently been substituted for the more preferred segmental resections and resultant deformities. Presented are 15 cases of oral cavity cancer involving resection of the mandible, immediate radiation to 10,000 rad, and primary reconstruction as irradiated mandibular autografts. The longest following is 4 years and 3 months, with a success rate of 66%. Morbidity is minimal as compared to autogenous bone grafting. Tumor size, previous radiation, or use of regional flaps have not been a factor in the success of this method in reconstruction of the mandible primarily.

  6. Are Aortic Stent Grafts Safe in Pregnancy?

    PubMed Central

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

    2015-01-01

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

  7. THE ROLE OF PASSENGER LEUKOCYTES IN THE ANOMALOUS SURVIVAL OF NEONATAL SKIN GRAFTS IN MICE

    PubMed Central

    Wachtel, Stephen S.; Silvers, Willys K.

    1972-01-01

    The anomalous survival of neonatal C3H skin grafts on CBA mice is correlated with the emigration of passenger leukocytes from the graft vasculature. Thus, newborn homografts whose leukocyte populations are eliminated by X-irradiation or by transient sojourn on an intermediate adult C3H host, do not display prolonged survival. Moreover, the continued presence of the newborn grafts is not requisite to the maintenance of the unresponsive state, an observation consonant with the demonstration that CBA mice bearing long-term neonatal C3H skin grafts are leukocyte chimeras. In contrast, neonatal male C57 skin grafts may persist on C57 females after heavy irradiation of the donor, or after passage on an intermediate adult male host. In addition, tolerance is broken by removal of long-persistant newborn grafts from hitherto unresponsive females, and chimerism is not detectable in female C57 mice tolerant of infant male isografts. Finally, leukocytes of neonatal C3H origin, inoculated subcutaneously into CBA males, may occasionally render these animals unresponsive to subsequent adult C3H skin homografts, whereas those taken from infant C57 males usually sensitize their adult female hosts. Thus, passenger leukocytes are implicated in the extended survival of C3H neonatal homografts on CBA recipients, but not in the persistence of H-Y-incompatible neonatal skin isografts on C57 females. PMID:4551219

  8. Reconstruction of traumatic orbital floor defects using irradiated cartilage homografts.

    PubMed

    Bevivino, J R; Nguyen, P N; Yen, L J

    1994-07-01

    The important role of orbital shape and volume reconstruction has been studied by many investigators. There is, however, no consensus on the material that should be used in the reconstruction of the orbit. Both biologic and alloplastic materials have been used, each with its advantages and disadvantages. Here we report our experience with irradiated costal cartilage homograft in the reconstruction of the orbital floor. Irradiated cartilage grafts were used in 31 patients with significant traumatic defects in the orbital floor. Long-term follow-up in 21 patients up to 48 months revealed no incidence of graft infections, extrusions, or clinically detectable graft distortion or resorption. Irradiated cartilage homograft appears to be an excellent material for reconstruction of the orbital floor. PMID:7944194

  9. Fat Grafting for Facial Filling and Regeneration.

    PubMed

    Coleman, Sydney R; Katzel, Evan B

    2015-07-01

    Plastic surgeons have come to realize that fat grafting can rejuvenate an aging face by restoring or creating fullness. However, fat grafting does much more than simply add volume. Grafted fat can transform or repair the tissues into which it is placed. Historically, surgeons have hesitated to embrace the rejuvenating potential of fat grafting because of poor graft take, fat necrosis, and inconsistent outcomes. This article describes fat grafting techniques and practices to assist readers in successful harvesting, processing, and placement of fat for optimal graft retention and facial esthetic outcomes.

  10. Bone Grafting the Cleft Maxilla

    MedlinePlus

    ... amount of bone from one place (usually the hip, head, ribs, or leg) and placing it in ... adjacent teeth into the bone graft; 2) prosthetic replacement (dental bridge); or 3) dental metallic bone implants. ...

  11. Surface modification by γ-ray-induced grafting of PDMAEMA/PEGMEMA onto PE films

    NASA Astrophysics Data System (ADS)

    Titaux, G. A.; Contreras-García, A.; Bucio, E.

    2009-07-01

    Radiation grafting of poly[2-(dimethylamino) ethyl methacrylate] (PDMAEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) onto polyethylene (PE) films was synthesized using gamma radiation from a 60Co source. PE was modified by the PDMAEMA and PEGMEMA by pre-irradiation and one-step method. Grafting as a function of the pre-irradiation dose between 50 and 200 kGy, dose rate of 9 kGy h -1, and monomer concentration 50% of PDMAEMA/PEGMEMA (1/1) in toluene. The characterization of the graft copolymer obtained was carried out by FTIR-ATR, TGA, and DSC. Stimuli-responsive behavior and critical pH point were studied by swelling in water, pH and thermo-responsive films of PE-g-(DMAEMA/PEGMEMA) presented a lower critical solution temperature (LCST) of 55 °C and critical pH point around 8.5.

  12. Nonallograft osteoconductive bone graft substitutes.

    PubMed

    Bucholz, Robert W

    2002-02-01

    An estimated 500,000 to 600,000 bone grafting procedures are done annually in the United States. Approximately (1/2) of these surgeries involve spinal arthrodesis whereas 35% to 40% are used for general orthopaedic applications. Synthetic bone graft substitutes currently represent only 10% of the bone graft market, but their share is increasing as experience and confidence in their use are accrued. Despite 15 to 20 years of clinical experience with various synthetic substitutes, there have been few welldesigned, controlled clinical trials of these implants. Synthetic bone graft substitutes consist of hydroxyapatite, tricalcium phosphate, calcium sulfate, or a combination of these minerals. Their fabrication technique, crystallinity, pore dimensions, mechanical properties, and resorption rate vary. All synthetic porous substitutes share numerous advantages over autografts and allografts including their unlimited supply, easy sterilization, and storage. However, the degree to which the substitute provides an osteoconductive structural framework or matrix for new bone ingrowth differs among implants. Disadvantages of ceramic implants include brittle handling properties, variable rates of resorption, poor performance in diaphyseal defects, and potentially adverse effects on normal bone remodeling. These inherent weaknesses have refocused their primary use to bone graft extenders and carriers for pharmaceuticals. The composition, histologic features, indications, and clinical experience of several of the synthetic bone graft substitutes approved for orthopaedic use in the United States are reviewed. PMID:11937865

  13. Bilateral internal thoracic artery grafting

    PubMed Central

    2013-01-01

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

  14. Costal Grafting in Mandibular Reconstruction

    PubMed Central

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

    2015-01-01

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

  15. Lysozyme immobilization onto PVC catheters grafted with NVCL and HEMA for reduction of bacterial adhesion

    NASA Astrophysics Data System (ADS)

    Guadarrama-Zempoalteca, Yesica; Díaz-Gómez, Luis; Meléndez-Ortiz, H. Iván; Concheiro, Angel; Alvarez-Lorenzo, Carmen; Bucio, Emilio

    2016-09-01

    The aim of the present work was to functionalize poly(vinyl chloride) (PVC) urinary catheters with grafted copolymers that can improve the biocompatibility and serve as binding points of lysozyme. PVC catheters were modified by grafting a mixture of N-vinylcaprolactam (NVCL) and 2-hydroxyethylmethacrylate (HEMA) applying a gamma-ray pre-irradiation method. The effect of absorbed dose, monomer concentration, temperature, and reaction time on the grafting percentage was evaluated. The grafted catheters were characterized regarding surface composition (FTIR-ATR spectroscopy), thermal properties (DSC and TGA) and swelling in aqueous medium. Lysozyme was directly coupled onto PVC-g-(NVCL/HEMA) previously activated using carbonyldiimidazole. Antimicrobial lytic activity of the modified catheters over time was tested against Micrococcus lysodeikticus. Lysozyme diminished the adhesion of Staphylococcus aureus onto the functionalized catheters, which may be suitable to prevent biofilm formation.

  16. Synthesis of partially hydrolyzed graft copolymer (H-Ipomoea hederacea seed gum-g-polyacrylonitrile).

    PubMed

    Yadav, Mithilesh; Singh, Somit Kumar; Rhee, Kyong Yop

    2013-06-01

    Polyacrylonitrile was grafted to Ipomoea hederacea (Ih) seed gum with 138.5% grafting yield and 43.55% grafting efficiency in a procedure that was performed under homogeneous microwave (MW) irradiation conditions for 70s in the absence of a radical initiator. Under similar conditions, a maximum grafting yield of 108% and 33.96% efficiency was achieved when the K2S2O8/ascorbic acid redox system was used as a radical initiator in a thermostatic water bath at 35 °C. The effects of reaction variables, such as monomer/Ih seed gum concentration, MW power, and exposure time on the graft copolymerization were studied. The partially hydrolyzed graft copolymer (H-Ih-g-PAN) formed a loose, porous surface and improved the water absorbency of Ih seed gum. The swelling behavior of H-Ih-g-PAN in various ionic salt (NaCl, MgCl2 and Na2SO4) solutions was also systematically investigated. The graft copolymer was further characterized using FTIR, TGA, XRD, and SEM. PMID:23618295

  17. Human nerve xenografting in nude mouse: Experimental study of graft revascularization

    SciTech Connect

    Duprez, K.; Bour, C.; Merle, M.; Duprez, A. )

    1991-01-01

    In the nude mouse, the congenital absence of T lymphocytes makes it possible to implant human nerve grafts without rejection or iatrogenic modifications (by immunosuppression) of human and murine tissues. Medial antebrachial cutaneous nerves were harvested from human cadavers 1-18 hours after death. These nerve grafts were implanted using different techniques in nude mice. All the grafts were macroscopically and microscopically revascularized 3 days after implantation. The modifications in time of this vascularization could be studied with precision through the use of repeated biopsies. The absence of human blood group antigens on the neovessel endothelium suggested a murine origin for angiogenesis. In situ DNA hybridizations with human and mouse DNA confirmed this origin. The topography of the revascularization (maximal in the perineurium and endoneurium) and the almost complete absence of human cells other than Schwann cells in the grafts at the peak of angiogenesis (26 days after grafting) suggested that Schwann cells had a determining role in graft vascularization. The irradiation of the nerve grafts with a dose of 30 grays before implantation did not modify significantly their histologic appearance compared to the control group, whereas an irradiation of 60 grays led to massive lesions. The neurotization of murine axons led to chimerical structures of normal histologic appearance, with vascularization similar to that observed in nonneurotized nerves. Through chimerism (human Schwann cells, murine vessels and axons) this model makes it possible to dissociate the respective role of the host and of the nerve graft in angiogenesis and suggests the existence of growth factors produced by the human Schwann cells.

  18. Design and Validation of an Augmented Hematopoietic Cell Transplantation-Comorbidity Index Comprising Pretransplant Ferritin, Albumin, and Platelet Count for Prediction of Outcomes after Allogeneic Transplantation.

    PubMed

    Vaughn, Jennifer E; Storer, Barry E; Armand, Philippe; Raimondi, Roberto; Gibson, Christopher; Rambaldi, Alessandro; Ciceri, Fabio; Oneto, Rosi; Bruno, Benedetto; Martin, Paul J; Sandmaier, Brenda M; Storb, Rainer; Sorror, Mohamed L

    2015-08-01

    Pretransplant values of serum ferritin, albumin, and peripheral blood counts were previously suggested to provide prognostic information about hematopoietic cell transplantation (HCT) outcomes. Whether these "biomarkers" have prognostic value independent of each other and the HCT-comorbidity index (HCT-CI) is unknown. We analyzed data from 3917 allogeneic HCT recipients at multiple sites in the United States and Italy using multivariate models including each biomarker and the HCT-CI. Data from all sites were then randomly divided into a training set (n = 2352) to develop weights for the relevant biomarkers to be added to the HCT-CI scores and a validation set (n = 1407) to validate an augmented HCT-CI compared with the original index. Multivariate analysis with data from one site showed that ferritin, albumin, and platelets-not neutrophils or hemoglobin-were independently associated with increased nonrelapse mortality (NRM) and decreased overall survival. Findings were validated in data from the other sites. Subsequently, in a training set from all sites, ferritin >2500 mg/dL (hazard ratio [HR], 1.69); albumin 3 to 3.5 g/dL (HR, 1.61) and <3.0 g/dL (HR, 2.27); and platelets 50 to <100,000 (HR, 1.28), 20 to <50,000 (HR, 1.29), and <20,000 (HR, 1.55) were statistically significantly associated with NRM. Weights were assigned to these laboratory values following the same equation used to design the original index. In the validation set, the addition of the biomarkers to the original index to develop an augmented HCT-CI resulted in a statistically significant increase in a higher c-statistic estimate for prediction of NRM (P = .0007). Ferritin, albumin, and platelet counts are important prognostic markers that further refine the discriminative power of the HCT-CI for transplant outcomes.

  19. Bone graft substitute: allograft and xenograft.

    PubMed

    Shibuya, Naohiro; Jupiter, Daniel C

    2015-01-01

    Rapid bone graft incorporation for structural rigidity is essential. Early range of motion, exercise, and weight-bearing are keys to rehabilitation. Structural and nonstructural bone grafts add length, height, and volume to alter alignment, function, and appearance. Bone graft types include: corticocancellous autograft, allograft, xenograft, and synthetic graft. Autogenic grafts are harvested from the patient, less likely to be rejected, and more likely to be incorporated; however, harvesting adds a procedure and donor site complication is common. Allografts, xenografts, and synthetic grafts eliminate secondary procedures and donor site complications; however, rejection and slower incorporation can occur.

  20. Craniofacial Bone Grafting: Wolff's Law Revisited

    PubMed Central

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

    2008-01-01

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

  1. History of graft-versus-host disease.

    PubMed

    Vriesendorp, Huib M; Heidt, Peter J

    2016-08-01

    Nuclear warfare at the end of World War II inspired Dick W. van Bekkum to study total-body irradiation (TBI) in animal models. After high-dose TBI, mice died from "primary disease" or bone marrow (BM) aplasia. Intravenous administration of allogeneic BM cells delayed mortality but did not prevent it. Initially the delayed deaths were said to be caused by "secondary disease," which was later renamed graft-versus-host disease (GvHD). GvHD is caused by donor T lymphocytes that destroy recipient cells in skin, intestinal mucosa, bile ducts, and lymph nodes. GvHD is opposed by host-versus-graft disease (HvGD), in which host T lymphocytes destroy the administered allogeneic BM cells, including the administered T lymphocytes of the BM donor. In 1960, van Bekkum became the director of the Radiobiological Institute of the Dutch Organization for Applied Scientific Research TNO, Rijswijk, The Netherlands, where he built a multidisciplinary team that defined the variables controlling the outcome of a BM transplant. The team published their early results in the Journal of Experimental Hematology [1981;9:904-916 and 1956;4:482-488]. Later, protocols were established for BM transplantation (BMT) in patients with severe combined immunodeficiency disease, leukemia, lymphoma, and other diseases of the hematopoietic system. This review honors the scientific contributions made by Dick van Bekkum and his team in defining the four dominant variables for improving the therapeutic ratio of allogeneic BMT and in fostering the international collaboration necessary to translate this knowledge into current clinical practice. PMID:27235758

  2. Plant grafting: new mechanisms, evolutionary implications

    PubMed Central

    Goldschmidt, Eliezer E.

    2014-01-01

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

  3. Graft Diameter matters in Hamstring ACL reconstruction

    PubMed Central

    Clatworthy, Mark

    2016-01-01

    Objective: Recently techniques have been developed to increase graft diameter in hamstring ACL reconstruction with the hope to decrease graft failure. To date there is limited evidence to show that a smaller graft diameter results in a higher ACL failure rate. Method: The factors for failure in 1480 consecutive single surgeon hamstring ACL reconstructions were evaluated prospectively. Patients were followed for 2-15 years. A multivariate analysis was performed which looked at graft size, age, sex, time to surgery, meniscal integrity, meniscal repair and ACL graft placement to determine whether graft diameter matters in determining the failure of hamstring ACL reconstruction. Results: Graft diameters ranged from 6-10 mm. The mean graft diameter for all patients was 7.75 mm. 83 ACL reconstructions failed. The mean size of graft failures was 7.55 mm ACL reconstructions that failed had a significantly smaller hamstring graft diameter p=0.001. The Hazard Ratio for a smaller diameter graft is 0.517 p=<0.0001. For every 1 mm decrease in graft diameter there is a 48.3% higher chance of failure. The multivariate analysis showed a hazard ratio of 0.543 p=0.002. For every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure. Conclusion: Smaller diameter hamstring grafts do have a higher failure rate. Grafts ≤ 7.5 mm had twice the failure rate of grafts ≥8 mm using a multivariate analysis for every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure.

  4. Tissue irradiator

    DOEpatents

    Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

    1975-12-16

    A tissue irradiator is provided for the in-vivo irradiation of body tissue. The irradiator comprises a radiation source material contained and completely encapsulated within vitreous carbon. An embodiment for use as an in- vivo blood irradiator comprises a cylindrical body having an axial bore therethrough. A radioisotope is contained within a first portion of vitreous carbon cylindrically surrounding the axial bore, and a containment portion of vitreous carbon surrounds the radioisotope containing portion, the two portions of vitreous carbon being integrally formed as a single unit. Connecting means are provided at each end of the cylindrical body to permit connections to blood- carrying vessels and to provide for passage of blood through the bore. In a preferred embodiment, the radioisotope is thulium-170 which is present in the irradiator in the form of thulium oxide. A method of producing the preferred blood irradiator is also provided, whereby nonradioactive thulium-169 is dispersed within a polyfurfuryl alcohol resin which is carbonized and fired to form the integral vitreous carbon body and the device is activated by neutron bombardment of the thulium-169 to produce the beta-emitting thulium-170.

  5. Simultaneous radiation induced graft polymerization of N-vinyl-2-pyrrolidone onto polypropylene non-woven fabric for improvement of blood compatibility

    NASA Astrophysics Data System (ADS)

    Li, Rong; Wang, Hengdong; Wang, Wenfeng; Ye, Yin

    2013-07-01

    In this study, N-vinyl-2-pyrrolidone (NVP) was grafted onto polypropylene non-woven fabric (PPNWF) through a simultaneous irradiation induced graft polymerization technique. Effect of the parameters of graft polymerization, i.e., monomer concentration, absorbed dose and dose rate, on the degree of grafting (DG) was investigated. The graft polymerization of NVP was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). A contact angle goniometry was used to test water contact angle (WCA) of original PPNWF and modified samples. The in vitro blood compatibility, including hemolysis, protein adsorption, platelet adhesion and activated partial thromboplastin time (APTT) of tested specimens, was evaluated. The results demonstrated that the hemocompatibility of PPNWF was improved via graft polymerization of NVP.

  6. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via UV-induced graft polymerization of N-vinyl pyrrolidone.

    PubMed

    Luan, Shifang; Zhao, Jie; Yang, Huawei; Shi, Hengchong; Jin, Jing; Li, Xiaomeng; Liu, Jingchuan; Wang, Jianwei; Yin, Jinghua; Stagnaro, Paola

    2012-05-01

    Poly(N-vinyl pyrrolidone) (PNVP) was covalently grafted onto the surface of biomedical poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via a technique of UV-induced graft polymerization combined with plasma pre-treatment. The surface graft polymerization of N-vinyl pyrrolidone (NVP) was confirmed by ATR-FTIR and XPS. Effect of the parameters of graft polymerization, i.e., the initiator concentration, the UV irradiation time and the monomer concentration on the grafting density was investigated. The morphology and the wettability of the PNVP-modified surfaces were characterized by AFM and DSA, respectively. Protein adsorption and platelet adhesion were obviously suppressed after PNVP was grafted onto the SEBS substrates. PMID:22264686

  7. Costal Cartilage Grafts in Rhinoplasty.

    PubMed

    Fedok, Fred G

    2016-01-01

    Cartilage grafts are regularly used in rhinoplasty. Septal and auricular donor sites are commonly used. Many situations compel the surgeon to use other alternative donor sites, including revision rhinoplasty and trauma. Many patients have a small amount of native septal cartilage and are unable to provide adequate septal cartilage to be used for frequently performed rhinoplasty maneuvers. The rib cage provides an enormous reserve of costal cartilage that can be carved into a variety of necessary grafts. A description of the technique of harvesting costal cartilage, a review of complications and management, and illustrative cases examples are included. PMID:26616708

  8. Recanalization of an Occluded Infrainguinal Vein Graft Complicated by Graft Aneurysm

    SciTech Connect

    Kakani, Nirmal; Travis, Simon; Hancock, John

    2007-11-15

    The technique of subintimal angioplasty has been described for the recanalisation of native vessels after occlusion of infrainguinal vascular bypass grafts. We report a case in which an attempt at such treatment resulted in inadvertent but successful recanalisation of the occluded vein graft instead. This was complicated by graft perforation and subsequent graft aneurysm which was successfully treated with a covered stent.

  9. High pre-transplant serum ferritin and busulfan-thiotepa conditioning regimen as risk factors for hepatic sinusoidal obstructive syndrome after autologous stem cell transplantation in patients with malignant lymphoma.

    PubMed

    Hwang, Doh Yu; Kim, Soo-Jeong; Cheong, June-Won; Kim, Yundeok; Jang, Ji Eun; Lee, Jung Yeon; Min, Yoo Hong; Yang, Woo Ick; Kim, Jin Seok

    2016-01-01

    Few studies have evaluated the risk factors for hepatic sinusoidal obstructive syndrome (SOS) in patients with malignant lymphoma receiving autologous stem cell transplantation (ASCT). We retrospectively analyzed 132 malignant lymphoma patients who underwent ASCT. Intravenous busulfan-based conditioning regimens were used in 108 (81.8%) patients. The combination of heparin and ursodeoxycholic acid was used for prophylaxis of SOS. Hepatic SOS was developed in 10 (7.6%) patients at a median of 30 days post-ASCT. In nine (90.0%) patients, SOS was diagnosed after 20 days post-ASCT. Two patients developed severe SOS and eventually died from multiple organ failure. In multivariate analysis, the use of the busulfan-thiotepa conditioning regimen (p = 0.003) and a high pre-transplant serum ferritin level (≥ 950 ng/mL) (p = 0.003) were risk factors for hepatic SOS. The evaluation of pre-transplant serum ferritin may be helpful in determining the most appropriate conditioning regimen with a lower risk of SOS.

  10. Primary Breast Augmentation with Fat Grafting.

    PubMed

    Coleman, Sydney R; Saboeiro, Alesia P

    2015-07-01

    The controversy over fat grafting to the breasts has now been settled. In 2009, the American Society of Plastic Surgeons Fat Graft Task Force stated that "Fat grafting may be considered for breast augmentation and correction of defects associated with medical conditions and previous breast surgeries; however, results are dependent on technique and surgeon expertise." This article discusses the history, indications, planning, complications, and present technique of fat grafting to the breast using the Coleman technique.

  11. Highly hydrophilic ultra-high molecular weight polyethylene powder and film prepared by radiation grafting of acrylic acid

    NASA Astrophysics Data System (ADS)

    Wang, Honglong.; Xu, Lu.; Li, Rong.; Pang, Lijuan.; Hu, Jiangtao.; Wang, Mouhua.; Wu, Guozhong.

    2016-09-01

    The surface properties of ultra-high molecular weight polyethylene (UHMWPE) are very important for its use in engineering or composites. In this work, hydrophilic UHMWPE powder and film were prepared by γ-ray pre-irradiation grafting of acrylic acid (AA) and further neutralization with sodium hydroxide solution. Variations in the chemical structure, grafting yield and hydrophilicity were investigated and compared. FT-IR and XPS analysis results showed that AA was successfully grafted onto UHMWPE powder and film; the powder was more suitable for the grafting reaction in 1 wt% AA solution than the film. Given a dose of 300 kGy, the grafting yield of AA was ∼5.7% for the powder but ∼0.8% for the film under identical conditions. Radiation grafting of a small amount of AA significantly improved the hydrophilicity of UHMWPE. The water contact angle of the UHMWPE-g-PAA powder with a grafting yield of AA at ∼5.7% decreased from 110.2° to 68.2°. Moreover, the grafting powder (UHMWPE-g-PAA) exhibited good dispersion ability in water.

  12. Organosiloxane-grafted natural polymer coatings

    DOEpatents

    Sugama, Toshifumi

    1998-01-01

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

  13. Acute kidney injury after orthotopic liver transplantation using living donor versus deceased donor grafts: A propensity score-matched analysis.

    PubMed

    Hilmi, Ibtesam A; Damian, Daniela; Al-Khafaji, Ali; Sakai, Tetsuro; Donaldson, Joseph; Winger, Daniel G; Kellum, John A

    2015-09-01

    Acute kidney injury (AKI) is a common complication after liver transplantation (LT). Few studies investigating the incidence and risk factors for AKI after living donor liver transplantation (LDLT) have been published. LDLT recipients have a lower risk for post-LT AKI than deceased donor liver transplantation (DDLT) recipients because of higher quality liver grafts. We retrospectively reviewed LDLTs and DDLTs performed at the University of Pittsburgh Medical Center between January 2006 and December 2011. AKI was defined as a 50% increase in serum creatinine (SCr) from baseline (preoperative) values within 48 hours. One hundred LDLT and 424 DDLT recipients were included in the propensity score matching logistic model on the basis of age, sex, Model for End-Stage Liver Disease score, Child-Pugh score, pretransplant SCr, and preexisting diabetes mellitus. Eighty-six pairs were created after 1-to-1 propensity matching. The binary outcome of AKI was analyzed using mixed effects logistic regression, incorporating the main exposure of interest (LDLT versus DDLT) with the aforementioned matching criteria and postreperfusion syndrome, number of units of packed red blood cells, and donor age as fixed effects. In the corresponding matched data set, the incidence of AKI at 72 hours was 23.3% in the LDLT group, significantly lower than the 44.2% in the DDLT group (P = 0.004). Multivariate mixed effects logistic regression showed that living donor liver allografts were significantly associated with reduced odds of AKI at 72 hours after LT (P = 0.047; odds ratio, 0.31; 95% confidence interval, 0.096-0.984). The matched patients had lower body weights, better preserved liver functions, and more stable intraoperative hemodynamic parameters. The donors were also younger for the matched patients than for the unmatched patients. In conclusion, receiving a graft from a living donor has a protective effect against early post-LT AKI. PMID:25980614

  14. The Right Gastroepiploic Artery Graft for Coronary Artery Bypass Grafting: A 30-Year Experience

    PubMed Central

    Suma, Hisayoshi

    2016-01-01

    Throughout its 30-year history, the right gastroepiploic artery (GEA) has been useful for in situ grafts in coronary artery bypass grafting (CABG). The early graft patency rate is high, and the late patency rate has improved by using the skeletonized GEA graft and proper target selection, which involves having a target coronary artery with a tight >90% stenosis. Total arterial revascularization with the internal thoracic artery and GEA grafts is an option for achieving better outcomes from CABG procedures. PMID:27525230

  15. Hydrolyzed polyacrylamide grafted maize starch based microbeads: application in pH responsive drug delivery.

    PubMed

    Setty, C Mallikarjuna; Deshmukh, Anand S; Badiger, Aravind M

    2014-09-01

    The present study details the synthesis, characterization and pharmaceutical application of hydrolysed polyacrylamide grafted maize starch (HPam-g-MS) as promising polymeric material for the development of pH responsive microbeads. Different grades of graft copolymer were synthesized by changing the net microwave irradiation time, while keeping all other factors constant. Acute oral toxicity study performed in rodents ensured the bio-safety of graft copolymer for clinical application. Various batches of aceclofenac loaded microbeads were prepared by ionic gelation method using synthesized graft copolymers and evaluated for formulation parameters. FTIR spectroscopy confirmed the chemical compatibility between drug and graft copolymer. Results of in vitro release study (USP type-II) carried out in two different pH media (pH 1.2 acid buffer and pH 7.4 phosphate buffer) showed that release rate of drug from developed microbeads was a function of both: (a) surrounding pH and (b) the matrix composition. The drug release was relatively higher at alkaline pH as compared to acidic pH and this feature is desirable from viewpoint of site specific drug delivery. A direct correlation was observed between percentage grafting and microbeads performance and it presents a scope for further research on application and optimization of HPam-g-MS based microbeads as drug delivery carriers. PMID:24971555

  16. Biotribological properties of UHMWPE grafted with AA under lubrication as artificial joint.

    PubMed

    Deng, Yaling; Xiong, Dangsheng; Wang, Kun

    2013-09-01

    Osteolysis caused by wear particles from polyethylene in the artificial hip joints is a serious issue. In order to endow the low friction and wear of the bearing surface of ultra-high molecular weight polyethylene (UHMWPE) artificial joint for a longer term, hydrophilic acrylic acid (AA) was grafted on UHMWPE powders with the method of ultraviolet irradiation and then the modified powders were hot pressed. The tribological properties of modified UHMWPE sliding against CoCrMo metallic plate on reciprocating tribometer under calf serum, saline and distilled water lubrication during a long-term friction were investigated. The measurement of Fourier-transform infrared spectroscopy indicates that AA is successfully grafted on the surface of UHMWPE powders by photo-induced graft polymerization. Contact angles of UHMWPE are decreased from 83° to 35° by grafting and the surface wettability is effectively improved. The tensile strength of modified sample decreases. The friction coefficient and wear rate of UHMWPE-g-PAA under calf serum, saline and distilled water lubrication are lower than that of untreated UHMWPE. With the increase of grafting ratio, the wear rate of UHMWPE-g-PAA decreases firstly and then increases. The modified UHMWPE with grafting ratio of 3.5 % has the lowest wear rate, which is just quarter of the untreated UHMWPE. The hydrated PAA polymer brushes enclosed in the UHMWPE bulk material provide continuous lubrication during long term sliding.

  17. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods.

    PubMed

    Kaur, Inderjeet; Sharma, Neelam; Kumari, Vandna

    2013-11-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.80 × 10(-3) mol/L, [HNO3] = 112.68 × 10(-2) mol/L and [AN] = 114.49 × 10(-2) mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24%) was obtained at an optimum concentration of AN of 76.32 × 10(-2) mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated.

  18. Polyether-polyester graft copolymer

    NASA Technical Reports Server (NTRS)

    Bell, Vernon L. (Inventor)

    1987-01-01

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

  19. Synthesis of polytetrafluoroethylene based olefinic copolymer by gamma radiation grafting

    NASA Astrophysics Data System (ADS)

    Ferreto, H. F. R.; Lima, L. F. C. P.; Parra, D. F.; Zaia, V.; Lugão, A. B.

    2007-12-01

    High speed extrusion of linear low density polyethylene (LLDPE) is limited by processes shortcoming known as 'melt fracture' and 'sharkskin', which are surface defect of the extruded polymer. This defect results in a product with a rough surface that lacks luster and with poor surface properties. The fluoropolymer processing additives are used to eliminate the surface defect by coating the die wall and inducing slip at the coated fluoropolymer surface/LLDPE interface. The aim of this study was to obtain a recycled polytetrafluoroethylene polymer grafted with an olefin that could improve the extrudability of the LLDPE. The copolymer was obtained by irradiating recycled PTFE in an inert atmosphere followed by grafting an olefinic monomer the polymeric matrix (PTFE). After a certain time of contact, the copolymer was heat treated to allow recombination and elimination of the radicals, both in a reactive and/or inert atmosphere. The olefinic monomer used was 1,3-butadiene. The 1,3-butadiene monomer was found to be more effective with respect to grafting. The specimens were studied using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential thermogravimetry (DTG). The obtained copolymer (0.2-2.0 wt%) was mixed with LLDPE. The rheological properties of the mixture were determined with a torque rheometer. The results indicated that the developed process rendered a copolymer which when added to LLDPE, improved the extrusion process and eliminated the defect 'melt fracture'.

  20. Irradiation subassembly

    DOEpatents

    Seim, O.S.; Filewicz, E.C.; Hutter, E.

    1973-10-23

    An irradiation subassembly for use in a nuclear reactor is described which includes a bundle of slender elongated irradiation -capsules or fuel elements enclosed by a coolant tube and having yieldable retaining liner between the irradiation capsules and the coolant tube. For a hexagonal bundle surrounded by a hexagonal tube the yieldable retaining liner may consist either of six segments corresponding to the six sides of the tube or three angular segments each corresponding in two adjacent sides of the tube. The sides of adjacent segments abut and are so cut that metal-tometal contact is retained when the volume enclosed by the retaining liner is varied and Springs are provided for urging the segments toward the center of the tube to hold the capsules in a closely packed configuration. (Official Gazette)

  1. Vascular grafting strategies in coronary intervention

    NASA Astrophysics Data System (ADS)

    Knight, Darryl; Gillies, Elizabeth; Mequanint, Kibret

    2014-06-01

    With the growing need for coronary revascularizations globally, several strategies to restore blood flow to the heart have been explored. Bypassing the atherosclerotic coronary arteries with autologous grafts, synthetic prostheses and tissue-engineered vascular grafts continue to be evaluated in search of a readily available vascular graft with clinically acceptable outcomes. The development of such a vascular graft including tissue engineering approaches both in situ and in vitro is herein reviewed, facilitating a detailed comparison on the role of seeded cells in vascular graft patency.

  2. Acrylic polymer-grafted polypropylene sutures for covalent immobilization or reversible adsorption of vancomycin.

    PubMed

    García-Vargas, M; González-Chomón, C; Magariños, B; Concheiro, A; Alvarez-Lorenzo, C; Bucio, E

    2014-01-30

    Glycidyl methacrylate (GMA) and acrylic acid (AAc) were separately grafted onto polypropylene (PP) monofilament sutures by means of pre-irradiation using a (60)Co γ-source, with the purpose of loading vancomycin via (i) covalent immobilization through the glycidyl groups of GMA and (ii) ionic interaction with AAc moieties. The effect of absorbed radiation dose, monomer concentration, temperature and reaction time on the grafting degree was evaluated in detail. GMA grafting ranged from 25% to 800% while the grafting yield of AAc onto PP could be tuned between 9% and 454%, at doses from 5 to 50 kGy and a dose rate 13.7 kGy/h. Grafting of GMA or AAc decreased the decomposition temperature and made the sutures swellable to a certain extent. GMA grafting led to a continuous, smooth and thick coating, which was suitable for immobilization of up to 1.9 μg vancomycin per gram. The immobilized vancomycin enabled a reduction in the Staphylococcus aureus CFU adhered to the suture surface. On the other hand, dried AAc-functionalized sutures exhibited a rough and cracked surface which was responsible for a minor increase in the coefficient of friction. PP-g-AAc sutures exhibited pH-dependent swelling and remarkably high capability to host vancomycin (up to 109.9 mg/g), particularly those with an intermediate degree of grafting. Some AAc-functionalized sutures were shown able to inhibit bacterial growth after successive challenges with fresh lawns. Therefore, tuning the yield of grafting of GMA or AAc may enable the preparation of drug-suture combination products that retain or release, respectively, antimicrobial agents.

  3. Expert consensus document on the treatment of descending thoracic aortic disease using endovascular stent-grafts.

    PubMed

    Svensson, Lars G; Kouchoukos, Nicholas T; Miller, D Craig; Bavaria, Joseph E; Coselli, Joseph S; Curi, Michael A; Eggebrecht, Holger; Elefteriades, John A; Erbel, Raimund; Gleason, Thomas G; Lytle, Bruce W; Mitchell, R Scott; Nienaber, Christoph A; Roselli, Eric E; Safi, Hazim J; Shemin, Richard J; Sicard, Gregorio A; Sundt, Thoralf M; Szeto, Wilson Y; Wheatley, Grayson H

    2008-01-01

    Between 43,000 and 47,000 people die annually in the United States from diseases of the aorta and its branches and continues to increase. For the thoracic aorta, these diseases are increasingly treated by stent-grafting. No prospective randomized study exists comparing stent-grafting and open surgical treatment, including for disease subgroups. Currently, one stent-graft device is approved by the Food and Drug Administration for descending thoracic aortic aneurysms although two new devices are expected to obtain FDA approval in 2008. Stent-graft devices are used "off label" or under physician Investigational Device Exemption studies for other indications such as traumatic rupture of the aorta and aortic dissection. Early first-generation devices suffered from problems such as stroke with insertion, ascending aortic dissection or aortic penetration from struts, vascular injury, graft collapse, endovascular leaks, graft material failure, continued aneurysm expansion or rupture, and migration or kinking; however, the newer iterations coming to market have been considerably improved. Although the devices have been tested in pulse duplicators out to 10 years, long-term durability is not known, particularly in young patients. The long-term consequences of repeated computed tomography scans for checking device integrity and positioning on the risk of irradiation-induced cancer remains of concern in young patients. This document (1) reviews the natural history of aortic disease, indications for repair, outcomes after conventional open surgery, currently available devices, and insights from outcomes of randomized studies using stent-grafts for abdominal aortic aneurysm surgery, the latter having been treated for a longer time by stent-grafts; and (2) offers suggestions for treatment. PMID:18083364

  4. Irradiated foods

    MedlinePlus

    ... it reduces the risk of food poisoning . Food irradiation is used in many countries. It was first approved in the U.S. to prevent sprouts on white potatoes, and to control insects on wheat and in certain spices and seasonings.

  5. Radiolytic preparation and characterization of hydrophilic poly(acrylonitrile-co-vinylsulfonate)-grafted porous poly(tetrafluoroethylene) substrates

    NASA Astrophysics Data System (ADS)

    Park, Byeong-Hee; Sohn, Joon-Yong; Shin, Junhwa

    2016-01-01

    In this study, a hydrophilic copolymer of acrylonitrile (AN) and sodium vinylsulfonate (SVS) was grafted into a highly hydrophobic porous poly(tetrafluoroethylene) (PTFE) substrate using a gamma-ray irradiation method and the grafted substrate was used as a substrate for impregnating a hydrophilic ionomer, Nafion. The results of FT-IR and TGA analysis of the prepared substrate showed that the SVS/AN monomers were successfully grafted into the porous PTFE film. The results of degree of grafting, elemental analyzer, and contact angle analysis showed that the hydrophilicity of the prepared PTFE-g-P(AN-co-VS) substrate was increased with an increase in the amount of SVS/AN graft copolymers. Also, the results of FE-SEM and Gurley number measurement showed that the pores in the substrate were reduced as the amount of SVS/AN copolymers grafted into the substrate increased. The prepared porous PTFE-g-P(AN-co-VS) substrate at an irradiation dose of 70 kGy was found to impregnate Nafion ionomer effectively compared to the original porous PTFE substrate. These results suggest that the prepared PTFE-g-P(AN-co-VS) substrate can be effectively used for the impregnation of polymer electrolyte (Nafion) to prepare a reinforced composite membrane.

  6. Haploidentical stem cell transplantation in patients with pediatric solid tumors: preliminary results of a pilot study and analysis of graft versus tumor effects.

    PubMed

    Lang, P; Pfeiffer, M; Müller, I; Schumm, M; Ebinger, M; Koscielniak, E; Feuchtinger, T; Föll, J; Martin, D; Handgretinger, R

    2006-01-01

    Pediatric patients with relapsed metastatic tumors have a poor prognosis and new treatment strategies are warranted. We present preliminary results of a pilot study, evaluating the feasibility and toxicity of transplantation of haploidentical T and B cell depleted grafts with high numbers of NK cells. 6 patients with relapsed metastatic neuroblastomas (n = 4), rhabdomyosarcoma (n = 1) or Ewing's sarcoma (n = 1) after previous autologous transplantation received CD3/CD19 depleted grafts from mismatched family donors with a median number of 16 x 10 (6)/kg stem cells, 167 x 10 (6)/kg Natural Killer cells and only 5.4 x 10 (4)/kg residual T cells. A melphalan-based, reduced intensity conditioning was used. Despite pretransplant chemotherapy, patients entered transplantation with significant tumor burden. Primary engraftment occurred in 6/6 patients. One patient had secondary graft failure. Hematopoietic recovery was rapid (ANC > 0.5 x 10 (9)/L: 11 days (9-12); independence from platelet substitution: 8 days (7-11)). Four patients had acute GvHD grade II, limited chronic GvHD was observed in 2 patients. No transplant-related mortality and only low toxicity occurred. Four patients died from progression, two patients are alive. Overall median survival time is 6 months (2-11) to date. Analysis of posttransplant NK cell function revealed stable cytotoxic activity against K562 targets, whereas activity against neuroblastoma targets was low. Stimulation with cytokines and use of appropriate antibodies clearly enhanced specific lysis in vitro. In summary, these preliminary results indicate the feasibility and low toxicity even in intensively pre-treated patients with neuroblastomas/sarcomas. This approach may form the basis for posttransplant immunomodulation and other therapeutic strategies. Further experience is warranted to evaluate the method.

  7. Increased reactive oxygen species and exhaustion of quiescent CD34-positive bone marrow cells may contribute to poor graft function after allotransplants

    PubMed Central

    Hu, Yue; Shi, Min-Min; Wang, Yu-Tong; Wang, Yu; Zhang, Xiao-Hui; Xu, Lan-Ping; Liu, Kai-Yan; Deng, Hong-Kui; Huang, Xiao-Jun

    2016-01-01

    Poor graft function (PGF) is a fatal complication following allogeneic haematopoietic stem cell transplantation. However, the underlying mechanism is unclear. Effective cross-talk between haematopoietic stem cells (HSCs) and bone marrow microenvironment is important for normal haematopoiesis. Normal HSCs reside in a hypoxic bone marrow microenvironment that protects them from oxidative stress that would otherwise inhibit their self-renewal and results in bone marrow failure. Whether an increased level of reactive oxygen species (ROS) causes PGF following allotransplant is unclear. Using a prospective case-pair study, we identified increased levels of ROS in CD34+ bone marrow cells in subjects with PGF. Elevated ROS levels was associated with an increased frequency of DNA strand breaks, apoptosis, exhaustion of quiescent CD34+ cells and defective colony-forming unit plating efficiency, particularly in the CD34+CD38− fraction. Up-regulated intracellular p53, p21, caspase-3 and caspase-9 levels (but not p38) were detected in CD34+ cells, particularly in the CD34+CD38− fraction. To further study the potential role of ROS levels in post-transplant haematopoiesis, CD34+ bone marrow cells from subjects with good graft function were treated with H2O2. This increased ROS levels resulting in defective CD34+ cells, an effect partially reversed by N-acetyl-L-cysteine. Moreover, CD34+ bone marrow cells from the donors to subjects with poor or good graft function exhibited comparable haematopoietic reconstitution capacities in the xeno-transplanted NOD-PrkdcscidIL2rgnull mice. Thus, even if the transplanted donors' bone marrow CD34+ cells are functionally normal pre-transplant, ROS-induced apoptosis may contribute to the exhaustion of CD34+ bone marrow cells in subjects with PGF following allotransplant. PMID:27105530

  8. Structural mechanical properties of radiation-sterilized human Bone-Tendon-Bone grafts preserved by different methods.

    PubMed

    Gut, Grzegorz; Marowska, Joanna; Jastrzebska, Anna; Olender, Ewa; Kamiński, Artur

    2016-06-01

    To avoid the risk of infectious disease transmission from donor to recipient, allografts should be terminally sterilized. In the previous paper (Kaminski et al. in Cell Tissue Bank 10:215-219, 2009) we presented the effect of various methods of preservation (deep fresh freezing, glycerolization, lyophilization), followed by irradiation with different doses of electron beam (EB), on material (intrinsic) mechanical properties of human patellar tendons cut out as for anterior cruciate ligament reconstruction, obtained in failure tensile test. As structural mechanical properties are equally important to predict the behaviour of the graft as a whole functional unit, the purpose of the present paper was to show the results for failure load and elongation, obtained in the same experiment. Paired Bone-Tendon-Bone grafts (BTB) were prepared from cadaveric human patella tendons with both patellar and tibial attachments. They were preserved by deep freezing, glycerolization or lyophilization and subsequently EB-irradiated with the doses of 25, 35, 50 or 100 kGy (fresh-frozen grafts) or a single dose of 35 kGy (glycerolized and lyophilized grafts). Each experimental (irradiated) group was provided with control (non-irradiated), donor-matched group. The specimens from all groups were subjected to mechanical failure tensile test with the use of Instron system in order to measure their structural properties (failure load and elongation). All lyophilized grafts were rehydrated before mechanical testing. In our study we did not observe significant deterioration of structural mechanical properties of BTB grafts processed by fresh-freezing and then terminal sterilized with growing doses of EB up to 100 kGy. In contrast, BTB grafts processed by glycerolization or lyophilization and irradiated with 35 kGy showed significant decrease of failure load. Obtained results suggest that deep-frozen irradiated grafts retain their initial mechanical properties to an extent which does not

  9. Structural mechanical properties of radiation-sterilized human Bone-Tendon-Bone grafts preserved by different methods.

    PubMed

    Gut, Grzegorz; Marowska, Joanna; Jastrzebska, Anna; Olender, Ewa; Kamiński, Artur

    2016-06-01

    To avoid the risk of infectious disease transmission from donor to recipient, allografts should be terminally sterilized. In the previous paper (Kaminski et al. in Cell Tissue Bank 10:215-219, 2009) we presented the effect of various methods of preservation (deep fresh freezing, glycerolization, lyophilization), followed by irradiation with different doses of electron beam (EB), on material (intrinsic) mechanical properties of human patellar tendons cut out as for anterior cruciate ligament reconstruction, obtained in failure tensile test. As structural mechanical properties are equally important to predict the behaviour of the graft as a whole functional unit, the purpose of the present paper was to show the results for failure load and elongation, obtained in the same experiment. Paired Bone-Tendon-Bone grafts (BTB) were prepared from cadaveric human patella tendons with both patellar and tibial attachments. They were preserved by deep freezing, glycerolization or lyophilization and subsequently EB-irradiated with the doses of 25, 35, 50 or 100 kGy (fresh-frozen grafts) or a single dose of 35 kGy (glycerolized and lyophilized grafts). Each experimental (irradiated) group was provided with control (non-irradiated), donor-matched group. The specimens from all groups were subjected to mechanical failure tensile test with the use of Instron system in order to measure their structural properties (failure load and elongation). All lyophilized grafts were rehydrated before mechanical testing. In our study we did not observe significant deterioration of structural mechanical properties of BTB grafts processed by fresh-freezing and then terminal sterilized with growing doses of EB up to 100 kGy. In contrast, BTB grafts processed by glycerolization or lyophilization and irradiated with 35 kGy showed significant decrease of failure load. Obtained results suggest that deep-frozen irradiated grafts retain their initial mechanical properties to an extent which does not

  10. Endovascular Stent-Graft Repair as a Late Secondary Procedure After Previous Aortic Grafts

    SciTech Connect

    Matsagas, Miltiadis I. Anagnostopoulos, Constantine E.; Papakostas, John C.; DeRose, Joseph J.; Siminelakis, Stavros; Katsouras, Christos S.; Toumpoulis, Ioannis K.; Drossos, George E.; Michalis, Lampros K.

    2006-08-15

    Thoracic and abdominal aortic endovascular procedures as alternatives to aortic reoperations were studied in three different cases. An anastomotic aneurysm after previous thoracic aortic graft for coarctation, a second-stage elephant trunk repair (descending thoracic aortic aneurysm), and a secondary aneurysm proximal to a previous abdominal aortic graft were successfully treated with endovascular stent-grafts. During the follow-up period no lethal events or major aortic or graft-related complications were observed, except a type II endoleak in the anastomotic aortic aneurysm case. An endovascular stent-graft can be safely deployed into a previously implanted vascular graft, avoiding repeat surgery.

  11. Microwave induced synthesis of graft copolymer of binary vinyl monomer mixtures onto delignified Grewia optiva fiber: application in dye removal

    PubMed Central

    Gupta, Vinod Kumar; Pathania, Deepak; Priya, Bhanu; Singha, Amar Singh; Sharma, Gaurav

    2014-01-01

    Grafting method, through microwave radiation technique is very effective in terms of time consumption, cost effectiveness and environmental friendliness. Via this method, delignified Grewia optiva identified as a waste biomass, was graft copolymerized with methylmethacrylate (MMA) as an principal monomer in a binary mixture of ethyl methacrylate (EMA) and ethyl acrylate (EA) under microwave irradiation (MWR) using ascorbic acid/H2O2 as an initiator system. The concentration of the comonomer was optimized to maximize the graft yield with respect to the primary monomer. Maximum graft yield (86.32%) was found for dGo-poly(MMA-co-EA) binary mixture as compared to other synthesized copolymer. The experimental results inferred that the optimal concentrations for the comonomers to the optimized primary monomer was observed to be 3.19 mol/L × 10−1 for EMA and 2.76 mol/L × 10−1 for EA. Delignified and graft copolymerized fiber were subjected to evaluation of physicochemical properties such as swelling behavior and chemical resistance. The synthesized graft copolymers were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction techniques. Thermal stability of dGo-poly(MMA-co-EA) was found to be more as compared to the delignified Grewia optiva fiber and other graft copolymers. Although the grafting technique was found to decrease percentage crystallinity and crystallinity index among the graft copolymers but there was significant increase in their acid/base and thermal resistance properties. The grafted samples have been explored for the adsorption of hazardous methylene dye from aqueous system. PMID:25157348

  12. Cadaveric aorta implantation for aortic graft infection.

    PubMed

    Ali, Asad; Bahia, Sandeep S S; Ali, Tahir

    2016-01-01

    This case report describes a 73-year-old gentleman who underwent explantation of an infected prosthetic aorto-iliac graft and replacement with a cryopreserved thoracic and aorto-iliac allograft. The patient has been followed up a for more than a year after surgery and remains well. After elective tube graft repair of his abdominal aortic aneurysm (AAA) in 2003, he presented to our unit in 2012 in cardiac arrest as a result of a rupture of the distal graft suture line due to infection. After resuscitation he underwent aorto-bifemoral grafting using a cuff of the original aortic graft proximally. Distally the new graft was anastomosed to his common femoral arteries, with gentamicin beads left in situ. Post discharge the patient was kept under close surveillance with serial investigations including nuclear scanning, however it became apparent that his new graft was infected and that he would require aortic graft replacement, an operation with a mortality of at least 50%. The patient underwent the operation and findings confirmed a synthetic graft infection. This tube graft was explanted and a cryopreserved aorta was used to the refashion the abdominal aorta and its bifurcation. The operation required a return to theatre day one post operatively for a bleeding side branch, which was repaired. The patient went on to make a full recovery stepping down from the intensive therapy unit day 6 post operatively and went on to be discharged 32 days after his cryopreserved aorta implantation. PMID:27351624

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

    PubMed

    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. PMID:26091219

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

    PubMed

    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.

  15. Morphological Study of Poly(vinylbenzyl chloride)-Grafted Poly(ethylene-co-tetrafluoroethylene) [ETFE-g-PVBC] Films Using Small-Angle Neutron Scattering Analysis.

    PubMed

    Song, J M; Ko, B S; Sohn, J Y; Shin, J

    2016-06-01

    In this study, the effect of degree of the grafting and crosslinking on the morphology of the crystalline domain in poly(vinylbenzyl chloride)-grafted poly(ethylene-co-tetrafluoroethylene) [ETFE-g-PVBC] films was investigated using a SANS (small-angle neutron scattering) analysis. The grafted films can be used as a precursor for ion-exchange membrane. ETFE-g-PVBC films with various degrees of cross-linking were prepared by a simultaneous irradiation grafting of vinylbenzyl chloride (VBC) and divinylbenzene (DVB) onto an ETFE film. The SEM-EDX (scanning electron microscopy-energy dispersive X-ray spectroscopy) results of a cross-sectional distribution of ETFE-g-PVBC films showed that the chlorine atoms were well-distributed throughout the films. SANS profiles of the PVBC-grafted films in the absence of a DVB crosslinker showed that the crystalline domain peaks were observed and the peak maximum position shifted significantly from 0.032 Å-(-1) to 0.02 Å(-1) with an increase in the degree of grafting. However, peak maximum positions of the PVBC-grafted films in the presence of a DVB crosslinker shifted slightly from 0.02 Å(-1) to 0.024 Å(-1) with an increase in the amount of DVB monomer at same degree of grafting. These results indicate that the degree of grafting and crosslinking affect the morphology of the crystalline domain in the ETFE-g-PVBC films. PMID:27427709

  16. Modification of flax fibres by radiation induced emulsion graft copolymerization of glycidyl methacrylate

    NASA Astrophysics Data System (ADS)

    Moawia, Rihab Musaad; Nasef, Mohamed Mahmoud; Mohamed, Nor Hasimah; Ripin, Adnan

    2016-05-01

    Flax fibres were modified by radiation induced graft copolymerization of glycidyl methacrylate (GMA) by pre-irradiation method in an emulsion medium. The effect of reaction parameters on the degree of grafting (DOG) such as concentration of bleaching agent, absorbed dose, monomer concentration, temperature and reaction time were investigated. The DOG was found to be dependent on the investigated parameters. The incorporation of poly(GMA) grafts in the bleached flax fibres was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The structural and mechanical changes were evaluated by X-ray diffraction (XRD) and mechanical tester, respectively. The results revealed that reacting bleached flax fibres irradiated with 20 kGy with 5% GMA emulsion containing 0.5% polyoxyethylene-sorbitan monolaurate (Tween 20) surfactant at 40 °C for 1 h led to a maximum DOG of 148%. The grafted fibres showed sufficient mechanical strength and hydrophobicity which make them promising precursors for development of adsorbents after appropriate chemical treatments.

  17. Immune mechanisms in organ allograft rejection. V. Pivotal role of the cytotoxic-suppressor T cell subset in the rejection of heart grafts bearing isolated class I disparities in the inbred rat

    SciTech Connect

    Lowry, R.P.; Forbes, R.D.; Blackburn, J.H.; Marghesco, D.M.

    1985-11-01

    The cellular requirements for rejection of heart grafts bearing isolated major histocompatibility complex (MHC) subregion RT1A-encoded class I disparities was assessed by adoptive transfer. Sublethally irradiated (780 rads) (PVG X WF)F1 recipients of irradiated PVG-RT1r1 heart grafts were selectively reconstituted with spleen cells from syngeneic donors previously sensitized with two sequential PVG-RT1r1 skin grafts. PVG-RT1r1 heart grafts were rejected acutely in recipients reconstituted with 10 X 10(6) unfractionated immune spleen cells or inocula (5 X 10(6) cells) depleted of SIg+ cells, but additional depletion of cytotoxic T cells and their precursors resulted in marked prolongation of graft survival. Reducing the reconstituting inocula from 4 X 10(6) to 2.5 X 10(6) spleen cells prolonged graft survival to that observed in unreconstituted recipients. Additional studies were performed to define the immunologic basis for prolonged survival of PVG-RT1r1 heart grafts in homozygous PVG recipients. Although lymphoid cells of naive PVG failed to proliferate on coculture with irradiated PVG-RT1r1, bulk cultures yielding but weak and variable CTL generation, lymphoid cells from specifically sensitized PVG proliferated and generated greater cytotoxic T lymphocyte (CTL) activity under identical conditions, strongly suggesting, therefore, that prolonged heart graft survival in this strain combination is related to low CTL precursor frequency.

  18. Early secondary bone grafting of alveolar cleft defects. A comparison between chin and rib grafts.

    PubMed

    Borstlap, W A; Heidbuchel, K L; Freihofer, H P; Kuijpers-Jagtman, A M

    1990-07-01

    Since 1981 in cleft lip and palate patients a combined surgical-orthodontic procedure has been performed to eliminate the residual alveolar cleft. For early secondary bone grafting (before the eruption of the canine tooth) initially the graft tissue of choice was rib. Since 1984 chin bone has also been used. Sixty one patients with complete unilateral clefts were reviewed (mean age 9.5 years). 15.7% of the rib graft cases showed resorption of the graft of 50% and more. Such resorption was not found in any of the chin graft cases. No complications such as wound dehiscence, sequestration, excessive resorption of bone or recurrence of an oro-nasal fistula were found in the chin graft group. This leads to the conclusion that if enough bone is available in the chin region to bridge the defect, this graft is preferable to a rib graft.

  19. The potential role of pretransplant MIBG diagnostic scintigraphy in targeted administration of 131I-MIBG accompanied by ASCT for high-risk and relapsed neuroblastoma: a pilot study.

    PubMed

    Hamidieh, Amir Ali; Beiki, Davood; Paragomi, Pedram; Fallahi, Babak; Behfar, Maryam; Fard-Esfahani, Armaghan; Hosseini, Ashraf Sadat; Shamshiri, Ahmadreza; Eftekhari, Mohammad; Ghavamzadeh, Ardeshir

    2014-08-01

    MIBG is an effective component in treatment of neuroblastoma. Furthermore, MIBG scintigraphy is an imaging modality in primary assessments. None of the previous studies have evaluated the role of pretransplant MIBG scintigraphy in decision making for neuroblastoma treatment. We selected therapeutic regimen based on pretransplant (131) I-MIBG scintigraphy. Twenty high-risk patients were enrolled. On day -30, patients underwent diagnostic MIBG scintigraphy. Patients were then subdivided into two groups (10 cases in each arm). MIBG-avid subgroup received MIBG (12 mCi/kg), etoposide (1200 mg/m2), carboplatin (1500 mg/m2), and melphalan (210 mg/m2). Non-MIBG-avid subgroup received etoposide (600 mg/m2), carboplatin (1200 mg/m2), and melphalan (150 mg/m2). Patients received CRA after ASCT. Mean age at diagnosis was 42.5 months (range, 17-65) in MIBG-avid and 38.9 months (range, 18-65) in non-MIBG-avid patients. Mean age at diagnosis and transplantation did not reveal significant difference between two subgroups. In MIBG-avid patients, the three-yr OS was 66 ± 21%. In MIBG-non-avid subgroup, the three-yr OS was 53 ± 20%. In MIBG-avid and non-MIBG-avid subgroups, the three-yr EFS were 66 ± 21% and 47 ± 19%, respectively. These findings may suggest an effective role in selecting the therapeutic strategy for pre-ASCT MIBG scintigraphy in high-risk neuroblastoma. MIBG-avid subset may benefit from the combination of therapeutic MIBG and high dose of chemotherapy.

  20. Novel expansion techniques for skin grafts.

    PubMed

    Kadam, Dinesh

    2016-01-01

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

  1. Hydrocarbon compositions containing polyolefin graft polymers

    SciTech Connect

    Kapuscinski, M.M.; Liu, C.S.; Hart, W.P.; Grina, L.D.

    1987-02-03

    A graft polymer is described comprising an oil-soluble, substantially linear, carbon-carbon backbone polymer having graft polymerized thereon units derived from, as a functional monomer, the reaction product of (i) an unsaturated aldehyde or ketone and (ii) a primary or secondary amine which contains at least one nitrogen atom in a heterocyclic ring. The graft polymer is also described wherein the backbone polymer is a copolymer of ethylene-propylene or a terpolymer of ethylene-propylene-diene monomer.

  2. Organosiloxane-grafted natural polymer coatings

    DOEpatents

    Sugama, Toshifumi

    1998-12-01

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

  3. Novel expansion techniques for skin grafts

    PubMed Central

    Kadam, Dinesh

    2016-01-01

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

  4. Preoperative graft assessment in aortocoronary bypass surgery

    PubMed Central

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

    2016-01-01

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

  5. In vitro release studies of vitamin B 12 from poly N-vinyl pyrrolidone/starch hydrogels grafted with acrylic acid synthesized by gamma radiation

    NASA Astrophysics Data System (ADS)

    Eid, M.

    2008-12-01

    Co-polymeric hydrogels containing N-vinyl pyrrolidone and starch grafted with acrylic acid were synthesized by gamma radiation to be used as drug delivery system. Their gel contents, grafting swelling and thermal gravimetric analysis were evaluated. The gel content increases by increasing the irradiation dose up to 50 kGy, then decreases. The grafting percent increases by the increasing of acrylic acid. The thermal stability and the rate of the thermal decomposition changed according to the different compositions. The maximum rate of the thermal decomposition decreases by increasing the irradiation dose from 20 to 30 kGy and increases by increasing the irradiation dose from 30 to 70 kGy. The hydrogels loaded with vitamin B 12 demonstrated a decrease release in acidic medium than the neutral one.

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

    SciTech Connect

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

    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.

  7. Polymethacrylic acid grafted psyllium (Psy- g-PMA): a novel material for waste water treatment

    NASA Astrophysics Data System (ADS)

    Kumar, Ranvijay; Sharma, Kaushlendra; Tiwary, K. P.; Sen, Gautam

    2013-03-01

    Polymethacrylic acid grafted psyllium (Psy- g-PMA) was synthesized by microwave assisted method, which involves a microwave irradiation in synergism with silver sulfate as a free radical initiator to initiate grafting reaction. Psy- g-PMA grades have been synthesized and characterized on structural basis (elemental analysis, FTIR spectroscopy, intrinsic viscosity study) as well as morphological and thermal studies, taking psyllium as reference. The effects of reaction time, amount of monomer and silver sulfate (free radical initiator) on grafting of PMA on psyllium backbone have been studied. It is observed that all the grades of Psy- g-PMA have higher intrinsic viscosities than that of psyllium. The best synthesized grade was Psy- g-PMA having intrinsic viscosity of 6.93 and 58 % grafting of PMA on the main polymer backbone. Further Psy- g-PMA applications as flocculants for waste water treatment have been investigated. Psy- g-PMA resulted in higher decrease in the flocculation parameters such as total dissolved solid or total solids compared to psyllium. Hence the result shows the possible application of grafted psyllium in wastewater treatment.

  8. Graft union formation in artichoke grafting onto wild and cultivated cardoon: an anatomical study.

    PubMed

    Trinchera, Alessandra; Pandozy, Gianmarco; Rinaldi, Simona; Crinò, Paola; Temperini, Olindo; Rea, Elvira

    2013-12-15

    In order to develop a non-chemical method such as grafting effective against well-known artichoke soil borne diseases, an anatomical study of union formation in artichoke grafted onto selected wild and cultivated cardoon rootstocks, both resistant to Verticillium wilt, was performed. The cardoon accessions Belgio (cultivated cardoon) and Sardo (wild cardoon) were selected as rootstocks for grafting combinations with the artichoke cv. Romolo. Grafting experiments were carried out in the autumn and spring. The anatomical investigation of grafting union formation was conducted by scanning electron microscopy (SEM) on the grafting portions at the 3rd, 6th, 10th, 12th day after grafting. For the autumn experiment only, SEM analysis was also performed at 30 d after grafting. A high affinity between artichoke scion and cardoon rootstocks was observed, with some genotype differences in healing time between the two bionts. SEM images of scion/rootstock longitudinal sections revealed the appearance of many interconnecting structures between the two grafting components just 3d after grafting, followed by a vascular rearrangement and a callus development during graft union formation. De novo formation of many plasmodesmata between scion and rootstock confirmed their high compatibility, particularly in the globe artichoke/wild cardoon combination. Moreover, the duration of the early-stage grafting process could be influenced not only by the scion/rootstock compatibility, but also by the seasonal conditions, being favored by lower temperatures and a reduced light/dark photoperiod. PMID:23932643

  9. Graft union formation in artichoke grafting onto wild and cultivated cardoon: an anatomical study.

    PubMed

    Trinchera, Alessandra; Pandozy, Gianmarco; Rinaldi, Simona; Crinò, Paola; Temperini, Olindo; Rea, Elvira

    2013-12-15

    In order to develop a non-chemical method such as grafting effective against well-known artichoke soil borne diseases, an anatomical study of union formation in artichoke grafted onto selected wild and cultivated cardoon rootstocks, both resistant to Verticillium wilt, was performed. The cardoon accessions Belgio (cultivated cardoon) and Sardo (wild cardoon) were selected as rootstocks for grafting combinations with the artichoke cv. Romolo. Grafting experiments were carried out in the autumn and spring. The anatomical investigation of grafting union formation was conducted by scanning electron microscopy (SEM) on the grafting portions at the 3rd, 6th, 10th, 12th day after grafting. For the autumn experiment only, SEM analysis was also performed at 30 d after grafting. A high affinity between artichoke scion and cardoon rootstocks was observed, with some genotype differences in healing time between the two bionts. SEM images of scion/rootstock longitudinal sections revealed the appearance of many interconnecting structures between the two grafting components just 3d after grafting, followed by a vascular rearrangement and a callus development during graft union formation. De novo formation of many plasmodesmata between scion and rootstock confirmed their high compatibility, particularly in the globe artichoke/wild cardoon combination. Moreover, the duration of the early-stage grafting process could be influenced not only by the scion/rootstock compatibility, but also by the seasonal conditions, being favored by lower temperatures and a reduced light/dark photoperiod.

  10. Gamma-Irradiated Sterile Cornea for Use in Corneal Transplants in a Rabbit Model

    PubMed Central

    Yoshida, Junko; Heflin, Thomas; Zambrano, Andrea; Pan, Qing; Meng, Huan; Wang, Jiangxia; Stark, Walter J.; Daoud, Yassine J.

    2015-01-01

    Purpose: Gamma irradiated corneas in which the donor keratocytes and endothelial cells are eliminated are effective as corneal lamellar and glaucoma patch grafts. In addition, gamma irradiation causes collagen cross inking, which stiffens collagen fibrils. This study evaluated gamma irradiated corneas for use in corneal transplantations in a rabbit model comparing graft clarity, corneal neovascularization, and edema. Methods: Penetrating keratoplasty was performed on rabbits using four types of corneal grafts: Fresh cornea with endothelium, gamma irradiated cornea, cryopreserved cornea, and fresh cornea without endothelium. Slit lamp examination was performed at postoperative week (POW) one, two, and four. Corneal clarity, edema, and vascularization were graded. Confocal microscopy and histopathological evaluation were performed. A P < 0.05 was statistically significant. Results: For all postoperative examinations, the corneal clarity and edema were statistically significantly better in eyes that received fresh cornea with endothelium compared to the other three groups (P < 0.05). At POW 1, gamma irradiated cornea scored better than the cryopreserved and fresh cornea without endothelium groups in clarity (0.9 vs. 1.5 and 2.6, respectively), and edema (0.6 vs. 0.8 and 2.0, respectively). The gamma irradiated corneas, cryopreserved corneas and the fresh corneas without endothelium, developed haze and edema after POW 2. Gamma irradiated cornea remained statistically significantly clearer than cryopreserved and fresh cornea without endothelium during the observation period (P < 0.05). Histopathology indicated an absence of keratocytes in gamma irradiated cornea. Conclusion: Gamma irradiated corneas remained clearer and thinner than the cryopreserved cornea and fresh cornea without endothelium. However, this outcome is transient. Gamma irradiated corneas are useful for lamellar and patch grafts, but cannot be used for penetrating keratoplasty. PMID:26180475

  11. Nanotribological study of grafted polymer

    NASA Astrophysics Data System (ADS)

    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.

  12. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

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

    1997-01-01

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

  13. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

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

    1997-04-08

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

  14. Fat grafting in facial rejuvenation.

    PubMed

    Marten, Timothy J; Elyassnia, Dino

    2015-04-01

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

  15. Grafted methylenediphosphonate ion exchange resins

    SciTech Connect

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

    1998-01-27

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

  16. Initiator Effects in Reactive Extrusion of Starch Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Design and development of multilayer vascular graft

    NASA Astrophysics Data System (ADS)

    Madhavan, Krishna

    2011-07-01

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

  18. Grafting techniques for Peyronie’s disease

    PubMed Central

    2016-01-01

    Peyronie’s disease (PD) is a benign fibrotic condition of the penile tunica albuginea. PD can be associated with penile pain, curvature, shortening, and erectile dysfunction (ED). The predominant and most bothersome symptom in affected patients is penile curvature, which can lead to inability to have sexual intercourse. In such cases, surgical correction of the curvature may be required. Plication techniques to correct curvature can cause penile shortening and therefore are generally reserved for curvatures <60°. Penile prosthesis implantation with simultaneous correction of curvature by various means is recommended in PD patients with ED not responding to medical therapy. Grafting techniques are the preferred surgical treatment in patients with penile curvatures >60°, short penis, or hourglass deformity. Patients scheduled for grafting surgery are required to have satisfactory erectile rigidity preoperatively. There are various grafting materials that can be used for closure of the tunica albuginea defect following plaque incision/excision. Both autologous and non-autologous grafts have been used for PD reconstructive surgery, and each graft has its advantages and disadvantages. Novel grafting materials are presented and discussed in this review. A major advantage of the available “off-the-shelf” grafts is that there is no harvesting from a donor site and, thus, morbidity is reduced, and operative times are minimized. Further investigations in regard to tissue-engineered grafts to improve surgical handling and postoperative outcomes are ongoing. Surgeon experience, careful patient selection, patient preference and type of penile deformity affect the choice of graft. This review summarizes the literature within the past 5 years regarding grafting techniques in PD. Surgical outcomes and limitations of grafting techniques are reported. A major objective of this review is dedicated to preoperative considerations and indications for grafting procedures, with

  19. Plasma Elevations of Tumor Necrosis Factor-Receptor-1 at Day 7 Post Allogeneic Transplant Correlate with Graft Versus Host Disease Severity and Overall Survival in Pediatric Patients

    PubMed Central

    Kitko, Carrie L.; Paczesny, Sophie; Yanik, Gregory; Braun, Thomas; Jones, Dawn; Whitfield, Joel; Choi, Sung W.; Hutchinson, Raymond J.; Ferrara, James L. M.; Levine, John E.

    2008-01-01

    Tumor necrosis factor-α (TNF-α) is known to play a role in the pathogenesis of graft-vs-host disease (GVHD), a cause of significant morbidity and treatment-related mortality (TRM) after allogeneic hematopoietic stem cell transplantation (HCT). We measured the concentration of TNF-Receptor-1 (TNFR1) in the plasma of HCT recipients as a surrogate marker for TNF-α both prior to transplant and at day 7 in 82 children who underwent a myeloablative allogeneic HCT at the University of Michigan between 2000 and 2005. GVHD grade II-IV developed in 49% of patients at a median of 20 days after HCT. Increases in TNFR1 level at day 7 post HCT, expressed as ratios compared to pre-transplant baseline, correlated with severity of GVHD (p=0.02). In addition, day 7 TNFR1 ratios > 2.5 baseline were associated with inferior 1 year overall survival (51% vs 74%, p=0.04). As an individual biomarker, TNFR1 lacks sufficient precision to be used as a predictor for the development of GVHD. However, increases in the concentration of TNFR1, which are detectable up to two weeks in advance of clinical manifestations of GVHD, correlate with survival in pediatric HCT patients. PMID:18541194

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

    NASA Astrophysics Data System (ADS)

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

    2007-06-01

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

  1. A comparison between the HeRO graft and conventional arteriovenous grafts in hemodialysis patients.

    PubMed

    Nassar, George M; Glickman, Marc H; McLafferty, Robert B; Croston, J Kevin; Zarge, Joseph I; Katzman, Howard E; Peden, Eric K; Lawson, Jeffrey H; Martinez, Jeffrey M; Thackeray, Lisa

    2014-01-01

    Venous stenosis and occlusion are a major cause of vascular access dysfunction and failure. The HeRO Graft bypasses occlusion and traverses stenosis with outflow directly into the central venous circulation. A randomized, multicenter study was conducted to evaluate the efficacy and safety of the HeRO Graft relative to conventional AV grafts. The design was to enroll 143 patients in a 2:1 randomization ratio between HeRO and conventional AV control groups. Data on 72 subjects (52 HeRO Graft and 20 AV graft controls) were obtained. The HeRO Graft and control cohorts were comparable in baseline characteristics. Adequacy of dialysis, bacteremia rates, and adverse events were consistent between groups. Twelve month Kaplan-Meier estimates for primary and secondary patency rates were 34.8% and 67.6% in the HeRO Graft cohort, and 30.6% and 58.4% in the control cohort. There was no statistical difference in terms of patency between groups. The rates of intervention were 2.2/year for HeRO Graft and 1.6/year for the control (p = 0.100). Median days to loss of secondary patency was 238 for HeRO Graft versus 102 for the control (p = 0.032). The HeRO Graft appears to provide similar patency, adequacy of dialysis, and bacteremia rates to those of conventional AV grafts.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  3. Thermal stability of grafted fibers. [Gamma radiation

    SciTech Connect

    Sundardi, F.; Kadariah; Marlianti, I.

    1983-10-01

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

  4. Acute graft-vs-host disease: pathobiology and management.

    PubMed

    Goker, H; Haznedaroglu, I C; Chao, N J

    2001-03-01

    Acute graft-vs-host disease (GVHD) is a major obstacle to safe allogeneic hematopoietic stem cell transplantation (HSCT), leading to a significant morbidity and mortality. GVHD occurs when transplanted donor T lymphocytes react to foreign host cells. It causes a wide variety of host tissue injuries. This review focuses on the pathobiological basis, clinical aspects, and current management strategies of acute GVHD. Afferent phase of acute GVHD starts with myeloablative conditioning, i.e., before the infusion of the graft. Total-body irradiation (TBI) or high-dose chemotherapy regimens cause extensive damage and activation in host tissues, which release inflammatory cytokines and enhance recipient major histocompatibility complex (MHC) antigens. Recognition of the foreign host antigens by donor T cells and activation, stimulation, and proliferation of T cells is crucial in the afferent phase. Effector phase of acute GVHD results in direct and indirect damage to host cells. The skin, gastrointestinal tract, and liver are major target organs of acute GVHD. Combination drug prophylaxis in GVHD is essential in all patients undergoing allogeneic HSCT. Steroids have remained the standard for the treatment of acute GVHD. Several clinical trials have evaluated monoclonal antibodies or receptor antagonist therapy for steroid-resistant acute GVHD, with different successes in a variety of settings. There are some newer promising agents like mycophenolate mofetil, glutamic acid-lysine-alanine-tyrosine (GLAT), rapamycin, and trimetrexate currently entering in the clinical studies, and other agents are in development. Future experimental and clinical studies on GVHD will shed further light on the better understanding of the disease pathobiology and generate the tools to treat malignant disorders with allogeneic HSCT with specific graft-vs-tumor effects devoid of GVHD. PMID:11274753

  5. Polyethylene oxide hydration in grafted layers

    NASA Astrophysics Data System (ADS)

    Dormidontova, Elena; Wang, Zilu

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

  6. Mixed allogeneic reconstitution (A+B----A) to induce donor-specific transplantation tolerance. Permanent acceptance of a simultaneous donor skin graft

    SciTech Connect

    Ildstad, S.T.; Wren, S.M.; Oh, E.; Hronakes, M.L. )

    1991-06-01

    Mixed allogeneic reconstitution, in which a mixture of T-cell-depleted bone marrow of syngeneic host and allogeneic donor type is transplanted into a lethally irradiated recipient (A+B----A), results in mixed lymphopoietic chimerism with engraftment of a mixture of both host and donor bone marrow elements. Recipients are specifically tolerant to donor both in vitro and in vivo. Donor-specific skin grafts survive indefinitely when they are placed after full bone marrow repopulation at 28 days, while third-party grafts are rapidly rejected. To determine whether a delay of a month or more for full bone marrow repopulation is required before a donor-specific graft can be placed, we have now examined whether tolerance induction can be achieved if a graft is placed at the time of bone marrow transplantation. Permanent acceptance of donor-specific B10.BR skin grafts occurred when mixed allogeneic chimerism (B10+B10.BR----B10) was induced and a simultaneous allogeneic donor graft placed. In vitro, mixed reconstituted recipients were specifically tolerant to the B10.BR donor lymphoid cells but fully reactive to MHC-disparate third-party (BALB/c; H-2dd) when assessed by mixed lymphocyte reaction (MLR) and cell-mediated lympholysis (CML) assays. These data therefore indicate that a donor-specific graft placed at the time of mixed allogeneic reconstitution is permanently accepted without rejection. To determine whether an allogeneic skin graft alone without allogeneic bone marrow would be sufficient to induce tolerance, syngeneic reconstitution (B10----B10) was carried out, and a simultaneous B10.BR allogeneic skin graft placed. Although skin grafts were prolonged in all recipients, all grafts rejected when full lymphopoietic repopulation occurred at 28 days.

  7. Combined use of the latissimus dorsi musculocutaneous free flap and split-rib grafts for cranial vault reconstruction

    SciTech Connect

    Stueber, K.; Salcman, M.; Spence, R.J.

    1985-08-01

    The patient described in this article had a large skull defect under the scalp which had been irradiated during treatment of a malignant brain tumor. The patient desired reconstruction of her defect. To provide good soft-tissue coverage for the bony reconstruction, a free latissimus dorsi musculocutaneous flap was used. The bony defect was partially reconstructed with split-rib grafts. The two parts of the reconstruction were combined into one operation, since it was felt that the well-vascularized muscle would ensure viability of the bone grafts.

  8. Intestinal helminths regulate lethal acute graft-versus-host disease and preserve the graft-versus-tumor effect in mice.

    PubMed

    Li, Yue; Chen, Hung-Lin; Bannick, Nadine; Henry, Michael; Holm, Adrian N; Metwali, Ahmed; Urban, Joseph F; Rothman, Paul B; Weiner, George J; Blazar, Bruce R; Elliott, David E; Ince, M Nedim

    2015-02-01

    Donor T lymphocyte transfer with hematopoietic stem cells suppresses residual tumor growth (graft-versus-tumor [GVT]) in cancer patients undergoing bone marrow transplantation (BMT). However, donor T cell reactivity to host organs causes severe and potentially lethal inflammation called graft-versus-host disease (GVHD). High-dose steroids or other immunosuppressive drugs are used to treat GVHD that have limited ability to control the inflammation while incurring long-term toxicity. Novel strategies are needed to modulate GVHD, preserve GVT, and improve the outcome of BMT. Regulatory T cells (Tregs) control alloantigen-sensitized inflammation of GVHD, sustain GVT, and prevent mortality in BMT. Helminths colonizing the alimentary tract dramatically increase the Treg activity, thereby modulating intestinal or systemic inflammatory responses. These observations led us to hypothesize that helminths can regulate GVHD and maintain GVT in mice. Acute GVHD was induced in helminth (Heligmosomoides polygyrus)-infected or uninfected BALB/c recipients of C57BL/6 donor grafts. Helminth infection suppressed donor T cell inflammatory cytokine generation and reduced GVHD-related mortality, but maintained GVT. H. polygyrus colonization promoted the survival of TGF-β-generating recipient Tregs after a conditioning regimen with total body irradiation and led to a TGF-β-dependent in vivo expansion/maturation of donor Tregs after BMT. Helminths did not control GVHD when T cells unresponsive to TGF-β-mediated immune regulation were used as donor T lymphocytes. These results suggest that helminths suppress acute GVHD using Tregs and TGF-β-dependent pathways in mice. Helminthic regulation of GVHD and GVT through intestinal immune conditioning may improve the outcome of BMT.

  9. Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review

    PubMed Central

    Dashe, Jesse; Parisien, Robert L; Cusano, Antonio; Curry, Emily J; Bedi, Asheesh; Li, Xinning

    2016-01-01

    AIM: To evaluate whether anterior cruciate ligament (ACL) allograft irradiation is effective for sterility without compromising graft integrity and increasing failure rate. METHODS: A literature search was conducted using PubMed, Cochrane, and Google. The following search terms were used: “Gamma irradiation AND anterior cruciate ligament AND allograft” with a return of 30 items. Filters used included: English language, years 1990-2015. There were 6 hits that were not reviewed, as there were only abstracts available. Another 5 hits were discarded, as they did not pertain to the topic of interest. There were 9 more articles that were excluded: Three studies were performed on animals and 6 studies were meta-analyses. Therefore, a total of 10 articles were applicable to review. RESULTS: There is a delicate dosing crossover where gamma irradiation is both effective for sterility without catastrophically compromising the structural integrity of the graft. Of note, low dose irradiation is considered less than 2.0 Mrad, moderate dose is between 2.1-2.4 Mrad, and high dose is greater than or equal to 2.5 Mrad. Based upon the results of the literature search, the optimal threshold for sterilization was found to be sterilization at less than 2.2 Mrad of gamma irradiation with the important caveat of being performed at low temperatures. The graft selection process also must include thorough donor screening and testing as well as harvesting the tissue in a sterile fashion. Utilization of higher dose (≥ 2.5 Mrad) of irradiation causes greater allograft tissue laxity that results in greater graft failure rate clinically in patients after ACL reconstruction. CONCLUSION: Allograft ACL graft gamma irradiated with less than 2.2 Mrad appears to be a reasonable alternative to autograft for patients above 25 years of age. PMID:27335815

  10. Cyclosporin A and methotrexate in canine marrow transplantation: engraftment, graft-versus-host disease, and induction of intolerance

    SciTech Connect

    Deeg, H.J.; Storb, R.; Weiden, P.L.; Raff, R.F.; Sale, G.E.; Atkinson, K.; Graham, T.C.; Thomas, E.D.

    1982-07-01

    We examined the effect of methotrexate (MTX) and cyclosporin A (Cy A) on engraftment, graft-versus-host disease (GVHD), and the induction of tolerance in dogs prepared for marrow transplantation by 9 Gy of total body irradiation and grafted with bone marrow and buffy coat cells. Nineteen dogs were given grafts from DLA-identical littermates followed by immunosuppression with Cy A for 25 or 100 days. All had sustained engraftment, and 12 became healthy long-term chimeras. Sixty dogs were given grafts from DLA-nonidentical unrelated donors. Among nine given MTX only postgrafting, one rejected the graft nd eight died with GVHD. Among 18 dogs given Cy A only postgrafting, eight failed to achieve engraftment, seven died of various causes, and three died with GVHD. Thirty-four dogs were given both MTX and Cy A in various regimens postgrafting. The only long-term survivors were 4 of 10 dogs given MTX on days 1, 3, 6, and 11 and Cy A from days 0 through 100. Two have chronic GVHD. We conclude that Cy A can induce graft-host tolerance across minor, but not major, histocompatibility differences. The combination of MTX early after transplantation with Cy A prevents failure of engraftment of histoincompatible marrow and some recipients become long-term survivors.

  11. Radiation Grafting for the Functionalization and Development of Smart Polymeric Materials.

    PubMed

    Pino-Ramos, Víctor H; Ramos-Ballesteros, Alejandro; López-Saucedo, Felipe; López-Barriguete, Jesús E; Varca, Gustavo H C; Bucio, Emilio

    2016-10-01

    Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the high-energy radiation exposition over the polymeric material. Thus, a microenvironment suitable for the reaction among monomer and/or polymer and the active sites is formed and then leading to propagation to form side-chain grafts. The modification of polymers using high-energy irradiation can be performed by the following methods: direct or simultaneous, pre-irradiation oxidative, and pre-irradiation. The most frequently used ones correspond to the pre-irradiation oxidative method as well as the direct one. Radiation-grafting has many advantages over other conventional methods because it does not require the use of catalyst nor additives to initiate the reaction and usually no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter is focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, the diverse applications of these materials in the biomedical area are also reported, with focus in drug delivery, sutures, and biosensors.

  12. Radiation Grafting for the Functionalization and Development of Smart Polymeric Materials.

    PubMed

    Pino-Ramos, Víctor H; Ramos-Ballesteros, Alejandro; López-Saucedo, Felipe; López-Barriguete, Jesús E; Varca, Gustavo H C; Bucio, Emilio

    2016-10-01

    Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the high-energy radiation exposition over the polymeric material. Thus, a microenvironment suitable for the reaction among monomer and/or polymer and the active sites is formed and then leading to propagation to form side-chain grafts. The modification of polymers using high-energy irradiation can be performed by the following methods: direct or simultaneous, pre-irradiation oxidative, and pre-irradiation. The most frequently used ones correspond to the pre-irradiation oxidative method as well as the direct one. Radiation-grafting has many advantages over other conventional methods because it does not require the use of catalyst nor additives to initiate the reaction and usually no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter is focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, the diverse applications of these materials in the biomedical area are also reported, with focus in drug delivery, sutures, and biosensors. PMID:27573505

  13. Graft impingement in anterior cruciate ligament reconstruction.

    PubMed

    Iriuchishima, Takanori; Shirakura, Kenji; Fu, Freddie H

    2013-03-01

    Anterior cruciate ligament (ACL) graft impingement is one of the most troubling complications in ACL reconstruction. In the previous strategy of isometric "non-anatomical" ACL reconstruction, posterior tibial tunnel placement and notchplasty were recommended to avoid graft impingement. Recently, the strategy of ACL reconstruction is shifting towards "anatomical" reconstruction. In anatomical ACL reconstruction, the potential risk of graft impingement is higher than in non-anatomical reconstruction because the tibial tunnel is placed at a more anterior portion on the tibia. However, there have been few studies reporting on graft impingement in anatomical ACL reconstruction. This study will provide a review of graft impingement status in both non-anatomical and the more recent anatomical ACL reconstruction techniques. In conclusion, with the accurate creation of bone tunnels within ACL native footprint, the graft impingement might not happen in anatomical ACL reconstruction. For the clinical relevance, to prevent graft impingement, surgeons should pay attention of creating correct anatomical tunnels when they perform ACL reconstruction. Level of evidence IV.

  14. Adaptive significance of root grafting in trees

    SciTech Connect

    Loehle, C.; Jones, R.

    1988-12-31

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

  15. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods.

    PubMed

    Kaur, Inderjeet; Sharma, Neelam; Kumari, Vandna

    2013-11-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.80 × 10(-3) mol/L, [HNO3] = 112.68 × 10(-2) mol/L and [AN] = 114.49 × 10(-2) mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24%) was obtained at an optimum concentration of AN of 76.32 × 10(-2) mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated. PMID:25685464

  16. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods

    PubMed Central

    Kaur, Inderjeet; Sharma, Neelam; Kumari, Vandna

    2013-01-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.80 × 10−3 mol/L, [HNO3] = 112.68 × 10−2 mol/L and [AN] = 114.49 × 10−2 mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24%) was obtained at an optimum concentration of AN of 76.32 × 10−2 mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated. PMID:25685464

  17. The effect of timing of gamma-irradiation on hemolysis and potassium release in leukoreduced red cell concentrates stored in SAGM.

    PubMed

    Serrano, K; Chen, D; Hansen, A L; Levin, E; Turner, T R; Kurach, J D R; Acker, J P; Devine, D V

    2014-05-01

    While irradiation of red cell concentrates (RCC) prevents graft-versus-host disease in susceptible transfusion recipients, it also damages red blood cells (RBC). To understand the ability of irradiation regulations to prevent transfusion of inferior units, we irradiated 980 RCC in saline-adenine-glucose-mannitol (SAGM) using various combinations of pre-irradiation age and post-irradiation storage times, and measured hemolysis and extracellular potassium levels. We observed unacceptably high hemolysis (>0·8%) in some RCC and elevated extracellular potassium levels in all gamma-irradiated RCC. This suggests that more restrictive storage times should be considered for RCC in SAGM.

  18. Flow characteristics in narrowed coronary bypass graft

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  19. Synthetic grafts for anterior cruciate ligament reconstruction.

    PubMed

    Longo, Umile Giuseppe; Rizzello, Giacomo; Berton, Alessandra; Fumo, Caterina; Maltese, Ludovica; Khan, Wasim S; Denaro, Vincenzo

    2013-11-01

    Several artificial biomaterials are available as ligament grafts. No ideal prosthesis mimicking natural human tissue have been found to date. The emerging field of tissue engineering holds the promise to use artificial ligaments as a viable alternative to the patellar or hamstring tendon autografts. Preliminary studies support the idea that these biomaterials have the ability to provide an alternative for autogenous grafts. However, no definitive conclusions have been found. Additionally, the incidence of postoperative complications varies within different studies. Prospective investigations are required to better understand the potential of artificial biomaterials as ligament grafts.

  20. Bioactive polymer grafting onto titanium alloy surfaces.

    PubMed

    Michiardi, A; Hélary, G; Nguyen, P-C T; Gamble, L J; Anagnostou, F; Castner, D G; Migonney, V

    2010-02-01

    Bioactive polymers bearing sulfonate (styrene sodium sulfonate, NaSS) and carboxylate (methylacrylic acid, MA) groups were grafted onto Ti6Al4V alloy surfaces by a two-step procedure. The Ti alloy surfaces were first chemically oxidized in a piranha solution and then directly subjected to radical polymerization at 70 degrees C in the absence of oxygen. The grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the toluidine blue colorimetric method. Toluidine blue results showed 1-5microgcm(-2) of polymer was grafted onto the oxidized Ti surfaces. Grafting resulted in a decrease in the XPS Ti and O signals from the underlying Ti substrate and a corresponding increase in the XPS C and S signals from the polymer layer. The ToF-SIMS intensities of the S(-) and SO(-) ions correlated linearly with the XPS atomic percent S concentrations and the ToF-SIMS intensity of the TiO(3)H(2)(-) ion correlated linearly with the XPS atomic per cent Ti concentration. Thus, the ToF-SIMS S(-), SO(-) and TiO(3)H(2)(-) intensities can be used to quantify the composition and amount of grafted polymer. ToF-SIMS also detected ions that were more characteristic of the polymer molecular structure (C(6)H(4)SO(3)(-) and C(8)H(7)SO(3)(-) from NaSS, C(4)H(5)O(2)(-) from MA), but the intensity of these peaks depended on the polymer thickness and composition. An in vitro cell culture test was carried out with human osteoblast-like cells to assess the influence of the grafted polymers on cell response. Cell adhesion after 30min of incubation showed significant differences between the grafted and ungrafted surfaces. The NaSS grafted surfaces showed the highest degree of cell adhesion while the MA-NaSS grafted surfaces showed the lowest degree of cell adhesion. After 4 weeks in vivo in rabbit femoral bones, bone was observed to be in direct contact with all implants. The percentage of mineralized tissue around the

  1. Use of Irradiated Foods

    NASA Technical Reports Server (NTRS)

    Brynjolfsson, A.

    1985-01-01

    The safety of irradiated foods is reviewed. Guidelines and regulations for processing irradiated foods are considered. The radiolytic products formed in food when it is irradiated and its wholesomeness is discussed. It is concluded that food irradiation processing is not a panacea for all problems in food processing but when properly used will serve the space station well.

  2. Polyvinyl alcohol {gamma}-ray grafted nylon 4 membrane for pervaporation and evapomeation

    SciTech Connect

    Lai, J.Y.; Chen, R.Y.; Lee, K.R

    1993-05-01

    Nylon 4, which possesses high mechanical strength and good affinity for water, can be considered as a liquid separation membrane. To improve the hydrophilicity of a Nylon 4 membrane for pervaporation and evapomeation processes, and to overcome the hydrolysis of polyvinyl alcohol (PVA), this study attempts to prepare a PVA-g-Nylon 4 membrane by {gamma}-ray irradiation grafting of vinyl acetate (VAc) onto Nylon 4 membrane, followed by hydrolysis treatment. The effects of down-stream pressure, irradiation dose, VAc monomer concentration, degree of grafting, feed composition, and size of alcohols on the separation of water-alcohol mixtures were studied. The surface properties of the prepared membrane were characterized by FTIR, ESCA, and a contact angle meter. A separation factor of 13.8 and a permeation rate of 0.352 kg/m{sup 2}-h can be obtained for a PVA-g-Nylon 4 membrane with a degree of grafting of 21.2% for a 90-wt% ethanol feed concentration. Compared to the pervaporation process, the evapomeation process has a significantly increased separation factor with a decreased permeation rate for the same PVA-g-Nylon 4 membrane. 24 refs., 9 figs., 4 tabs.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    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.

  7. Grafting of Methacrylonitrile and Ethyl Methacrylate onto Jute Fibre: Physico-chemical Characteristics of Grafted Jute

    NASA Astrophysics Data System (ADS)

    Mondal, Md. Ibrahim H.; Islam Farouqui, Faisul; Abu Hanif, Md.; Shafiur Rahman, G. M.; Asadul Hoque, Md.

    2005-10-01

    Modification of bleached jute fibre was done by graft co-polymerization with vinyl monomers e.g. methacrylonitrile and ethyl methacrylate, in aqueous medium using H2O2-Na2S2O3 as redox initiators. To make the process efficient, the optimized polymerization condition was established. The maximum percent grafting and grafting efficiency obtained at optimum grafting condition were 11.3 and 20.4% for MAN, respectively and that of 17.6 and 27.5% for EMA. Modification of bleached jute fibre with MAN and EMA reduced the loss in breaking strength and the yellowing on exposure to sunlight in air.

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

    PubMed

    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.

  9. Socket preservation and sinus augmentation using a medical grade calcium sulfate hemihydrate and mineralized irradiated cancellous bone allograft composite.

    PubMed

    Bagoff, Robert; Mamidwar, Sachin; Chesnoiu-Matei, Ioana; Ricci, John L; Alexander, Harold; Tovar, Nick M

    2013-06-01

    Regeneration and preservation of bone after the extraction of a tooth are necessary for the placement of a dental implant. The goal is to regenerate alveolar bone with minimal postoperative pain. Medical grade calcium sulfate hemihydrate (MGCSH) can be used alone or in combination with other bone grafts; it improves graft handling characteristics and particle containment of particle-based bone grafts. In this case series, a 1:1 ratio mix of MGCSH and mineralized irradiated cancellous bone allograft (MICBA) was mixed with saline and grafted into an extraction socket in an effort to maintain alveolar height and width for future implant placement. MGCSH can be used in combination with other bone grafts and can improve handling characteristics and graft particle containment of particle-based bone grafts. In the cases described, we found that an MGCSH:MICBA graft can potentially be an effective bone graft composite. It has the ability to act as a space maintainer and as an osteoconductive trellis for bone cells, thereby promoting bone regeneration in the extraction socket. MGCSH, a cost-effective option, successfully improved MICBA handling characteristics, prevented soft tissue ingrowth, and assisted in the regeneration of bone.

  10. Detection of irradiated liquor

    NASA Astrophysics Data System (ADS)

    Shengchu, Qi; Jilan, Wu; Rongyao, Yuan

    D-2,3-butanediol is formed by irradiation processes in irradiated liquors. This radiolytic product is not formed in unirradiated liquors and its presence can therefore be used to identify whether a liquor has been irradiated or not. The relation meso/dl≈1 for 2,3-butanediol and the amount present in irradiated liquors may therefore be used as an indication of the dose used in the irradiation.

  11. Technique in Cleft Rhinoplasty: The Foundation Graft.

    PubMed

    Gassner, Holger G; Schwan, Franziska; Haubner, Frank; Suárez, Gustavo A; Vielsmeier, Veronika

    2016-04-01

    Secondary cleft rhinoplasty represents a particular surgical challenge. The authors have identified the deficit in skeletal projection of the cleft-sided piriform rim as an important contributor to the pathology. A graft is described to augment the piriform crest on the cleft side. This foundation graft is suture fixated to the piriform crest after complete release of all soft tissue attachments to the alar base. The foundation graft is articulated with a long alar strut graft, which allows for powerful projection of the cleft-sided nasal tip. An advancement flap of vestibular skin is described to correct the vestibular stenosis. A transplant of diced cartilage in fascia is added to augment maxillary soft tissue volume. Subjective and objective measures of form and function are presented in a retrospective series of five cases, illustrating the efficacy of the techniques described. PMID:27097143

  12. Fluorescent Bioactive Corrole Grafted-Chitosan Films.

    PubMed

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

    2016-04-11

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

  13. The 5-Strand Hamstring Graft in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Lee, Rushyuan Jay; Ganley, Theodore J.

    2014-01-01

    The use of anterior cruciate ligament reconstruction in the pediatric and adolescent population has been increasing in recent years. Autograft hamstring graft is favored in this population, but these patients often have smaller hamstring tendons that yield smaller final graft constructs. These smaller grafts are associated with an increased need for revision surgery. We describe a technique for obtaining a larger-diameter anterior cruciate ligament graft construct from autologous hamstring graft without allograft supplementation. PMID:25473619

  14. Induction of tolerance to cardiac allografts in lethally irradiated rats reconstituted with syngeneic bone marrow

    SciTech Connect

    Hartnett, L.C.

    1983-01-01

    Generally, organ grafts from one individual animal to another are rejected in one-two weeks. However, if the recipients are given Total Body Irradiation (TBI) just prior to grafting, followed by reconstitution of hemopoietic function with syngeneic (recipient-type) bone marrow cells, then vascularized organ grafts are permanently accepted. Initially after irradiation, it is possible to induce tolerance to many strain combinations in rats. This thesis examines the system of TBI as applied to the induction of tolerance in LEW recipients of WF cardiac allografts. These two rat strains are mismatched across the entire major histocompatibility complex. When the LEW recipient are given 860 rads, a WF cardiac allograft and LEW bone marrow on the same day, 60% of the grafts are accepted. Methods employed to improve the rate of graft acceptance include: treating either donor or recipient with small amounts of methotrexate, or waiting until two days after irradiation to repopulate with bone marrow. It seems from these investigations of some of the early events in the induction of tolerance to allografts following TBI and syngeneic marrow reconstitution that an immature cell population in the bone marrow interacts with a radioresistant cell population in the spleen to produce tolerance to completely MHC-mismatched allografts.

  15. Biomaterials in Maxillofacial Surgery: Membranes and Grafts

    PubMed Central

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

    2011-01-01

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

  16. DNA nanosensor surface grafting and salt dependence

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  17. A comparative study on the graft copolymerization of acrylic acid onto rayon fibre by a ceric ion redox system and a γ-radiation method.

    PubMed

    Kaur, Inderjeet; Kumar, Raj; Sharma, Neelam

    2010-10-13

    Functionalization of rayon fibre has been carried out by grafting acrylic acid (AAC) both by a chemical method using a Ce(4+)-HNO(3) redox initiator and by a mutual irradiation (γ-rays) method. The reaction conditions affecting the grafting percentage have been optimized for both methods, and the results are compared. The maximum percentage of grafting (50%) by the chemical method was obtained utilizing 18.24 × 10(-3) moles/L of ceric ammonium nitrate (CAN), 39.68 × 10(-2) moles/L of HNO(3), and 104.08 × 10(-2) moles/L of AAc in 20 mL of water at 45°C for 120 min. For the radiation method, the maximum grafting percentage (60%) was higher, and the product was obtained under milder reaction conditions using a lower concentration of AAc (69.38 × 10(-2) moles/L) in 10 mL of water at an optimum total dose of 0.932 kGy. Swelling studies showed higher swelling for the grafted rayon fibre in water (854.54%) as compared to the pristine fibre (407%), while dye uptake studies revealed poor uptake of the dye (crystal violet) by the grafted fibre in comparison with the pristine fibre. The graft copolymers were characterized by IR, TGA, and scanning electron micrographic methods. Grafted fibre, prepared by the radiation-induced method, showed better thermal behaviour. Comparison of the two methods revealed that the radiation method of grafting of acrylic acid onto rayon fibre is a better method of grafting in comparison with the chemical method.

  18. Immunomodulation of vascular endothelium: Effects of ultraviolet B irradiation on vein allograft rejection

    SciTech Connect

    Marin, M.L.; Hardy, M.A.; Gordon, R.E.; Reemtsma, K.; Benvenisty, A.I. )

    1990-01-01

    Prosthetic grafts of vein allografts are inadequate as small-diameter vessel substitutes. We have applied ultraviolet B (UVB) irradiation to modulate the immunogenicity of vein allografts to avoid immunologic injury. The veins of male ACI rats were irradiated with UVB (60 mJ/cm2) in situ and transplanted to male ACI rats (autografts) and female Lewis rats (allografts). Nonirradiated veins served as controls. At 4, 7, 14, and 28 days, all grafts were patent and were studied for morphologic changes by scanning electron microscopy and for immunogold labeling of major histocompatibility complex class II antigen expression. In autografts, scanning electron microscopy demonstrated minimal endothelial loss after grafting, regardless of UVB irradiation. Untreated allografts showed severe endothelial injury 4, 7, and 14 days after transplantation. UVB irradiation of veins protected allografts from injury to the endothelium and basement membrane. Major histocompatibility complex class II-positive endothelial cells were not seen in autografts but were seen in 40% of cells 4 days after transplantation in untreated allografts. UVB-treated allografts showed MHC class II antigen expression labeling of 20% of the endothelial cells. Barr body analysis demonstrated the donor origin of these endothelial cells. UVB irradiation of rat vein allografts prolongs endothelial survival while decreasing endothelial surface expression of class II antigens. These data suggest that modification of vein immunogenicity with UVB irradiation may permit functional survival of small-vessel allografts without chronic immunosuppression.

  19. Autologous bone marrow transplantation following chemotherapy and irradiation in dogs with spontaneous lymphomas. [. gamma. rays

    SciTech Connect

    Bowles, C.A.; Bull, M.; McCormick, K.; Kadin, M.; Lucas, D.

    1980-09-01

    Thirty dogs with spontaneous lymphomas were administered two to six cycles of chemotherapy and were randomized into 3 groups to receive 800 rads of total body irradiation and autologous bone marrow transplantation. Of 10 dogs irradiated after chemotherapy-induced remission and infused with remission marrow (group 1), 8 (80%) had successful grafts and experienced remissions lasting 62 to 1024 days. Of 9 dogs irradiated during remission and infused with remission marrow mixed with autologous tumor cells (group 2), 6 (66%) had remission lasting 15 to 45 days. Eleven dogs with progressive tumor growth (relapse) following chemotherapy were irradiated and infused with remission marrow (group 3). Tumor remission lasting 39 to 350 days was observed in 5 dogs (45%) in this group, and 6 dogs died in less than 30 days. Dogs in groups 1 to 3 had median survival times of 216, 60, and 45 days, respectively. The prolonged survival times for dogs in group 1 compared to dogs in groups 2 and 3 suggest that protocols involving irradiation and autologous marrow grafting in this model would be most effective when these protocols are applied to animals having a minimum tumor burden at the time of irradiation and when the grafting is done with tumor-free autologous marrow.

  20. Pre-transplant achievement of negativity in minimal residual disease and French-American-British L1 morphology predict superior outcome after allogeneic transplant for Philadelphia chromosome positive acute lymphoblastic leukemia: an analysis of Southeast Asian patients.

    PubMed

    Ma, Liyuan; Hao, Siguo; Diong, Colin; Goh, Yeow-Tee; Gopalakrishnan, Sathish; Ho, Aloysius; Hwang, William; Koh, Liang-Piu; Koh, Mickey; Lim, Zi-Yi; Loh, Yvonne; Poon, Michelle; Tan, Lip-Kun; Tan, Patrick; Linn, Yeh-Ching

    2015-05-01

    To better understand predictive factors and improve the clinical outcome of allogeneic transplant for patients with Philadelphia positive acute lymphoblastic leukemia, we analyzed 67 Southeast Asian patients transplanted in our institutions. Multivariate analysis showed that disease status before transplant, year of transplant and, interestingly, French-American-British (FAB) subtype had a significant impact on overall survival (OS) and non-relapse mortality. Patients who were minimal residual disease (MRD) negative at transplant had a 3-year OS of 73% compared to those who were MRD positive (45%) and refractory (0%). The 3-year cumulative incidence of relapse was 18% and 36% for the MRD negative and positive groups, respectively. FAB L1 subtype had a significantly superior 3-year OS of 63% vs. 29% for L2 subtype. Pre-transplant use of a tyrosine kinase inhibitor significantly improved outcomes in univariate but not multivariate analysis, as it served to induce more patients into MRD negativity, which was the factor that directly improved transplant outcome.

  1. Role of TDTH and Tc populations in organ graft rejection. I. Functional analysis of graft-infiltrating T cells

    SciTech Connect

    Stepkowski, S.M.; Duncan, W.R.

    1986-10-01

    To analyze the role of T cell subpopulations in the rejection of organ allografts, we developed a new model for obtaining large numbers of graft infiltrating cells (GICs). We isolated W3/25+ Th/DTH and OX8+ Ts/c from vascularized, irradiated rat spleen allografts. W3/25+ GICs obtained from spleen allografts transplanted to normal recipients were highly effective in eliciting cardiac allograft rejection when transferred to sublethally irradiated recipients, however, the OX8+ subset was incapable of eliciting rejection. On the other hand, when OX8+ GICs were obtained from spleen allografts transplanted to previously immunized recipients, they were as efficient as the W3/25+ Th/DTH subset in eliciting cardiac allograft destruction. These results indicate that the W3/25+, OX8- T cell is required for the rejection of primary organ allografts, but that the rejection of a secondary allograft by an immune recipient may be mediated, independently, by both W3/25+ and OX8+ cells.

  2. The effects of different schedules of total-body irradiation in heterotopic vascularized bone transplantation. An experimental study in the Lewis rat

    SciTech Connect

    Gonzalez del Pino, J.; Benito, M.; Randolph, M.A.; Weiland, A.J. )

    1990-12-01

    To evaluate the effects of irradiation on heterotopically placed vascularized knee isografts, a single dose of 10 Gy of total-body irradiation was given to Lewis donor rats. Irradiation was delivered either 2 or 6 days prior to harvesting or subsequent transplantation, and evaluated at 1, 2, and 4 weeks after grafting. Irradiation caused endothelial depopulation of the graft artery, although vascular pedicle patency was maintained throughout the study. Bone graft viability and mineralization were normal. Dramatic changes in the bone marrow were seen that included an increase of its fat content (P less than 0.001), and a concomitant decrease in bone marrow-derived immunocompetent cells. These changes were more prominent in recipients of grafts from day -6 irradiated donor rats. Total-body irradiation did not prejudice the use of vascularized bone grafts, and exhibited an associated immunosuppresant effect over the vascular endothelium and bone marrow. This may be a further rational conditioning procedure to avoid recipient manipulation in vascularized bone allotransplantation.

  3. Cryopreservation of the tracheal grafts

    PubMed Central

    2009-01-01

    Transplantation of the trachea may become the preferred method for the reconstruction of extensive tracheal defects, however, several unresolved problems must be addressed, such as immunosuppression, preservation and donor shortage. In this manuscript, the cryopreservation of tracheal grafts is reviewed, which potentially is associated with a lessened immunological response. Cryopreservation may be used clinically for long-term preservation and may solve the donor shortage. It is very important to confirm the immunomodulatory effect of cryopreservation on tracheal allografts in order to expand the potential clinical application of tracheal transplantation in the future. The cartilage as well as the epithelium and lamina propria serve as targets for rejection. However, the effect of cryopreservation on chondrocytes could be associated with reduced allogenicity of the trachea. The long-term cryopreservation of cartilage must be investigated in basic research models of chondrocyte viability. Growth of cryopreserved tracheal allografts is less well understood. Further studies are needed to elucidate the mechanism of synergistic effects of both cryopreservation and adequate immunosuppression for tracheal xenografts. PMID:20046673

  4. Specific allogeneic unresponsiveness in irradiated dogs reconstituted with autologous bone marrow. [/sup 60/Co

    SciTech Connect

    Rapaport, F.T.; Bachvaroff, R.J.; Akiyama, N.; Sato, T.; Ferrebee, J.W.

    1980-07-01

    Hemopoietic reconstitution of supralethally irradiated adult dogs of the Cooperstown colony with their own stored bone marrow can produce long-term unresponsiveness to DLA-identical kidney allografts with no need for any additional immunosuppression. Eleven of 18 kidneys transplanted 12 h after replacement of autologous marrow into irradiated recipients currently survive with normal function for as long as 1417 d; 8 of 13 organs transplanted 28 h after marrow replacement, and 8 of 13 organs transplanted 36 h after marrow injection, currently survive up to 502 d, with no further treatment. Alterations in the timing and sequence of each procedure decrease the incidence of unresponsiveness. Survival and function of the kidney allografts were not affected by the rejection of successive skin grafts from the kidney donor. Skin grafts from other DLA-identical donors and DLA-incompatible skin grafts were rejected by the same recipients in uniform fashion.

  5. Cell-Assisted Lipotransfer Improves Volume Retention in Irradiated Recipient Sites and Rescues Radiation-Induced Skin Changes

    PubMed Central

    Luan, Anna; Duscher, Dominik; Whittam, Alexander J.; Paik, Kevin J.; Zielins, Elizabeth R.; Brett, Elizabeth A.; Atashroo, David A.; Hu, Michael S.; Lee, Gordon K.; Gurtner, Geoffrey C.; Longaker, Michael T.; Wan, Derrick C.

    2016-01-01

    Radiation therapy is not only a mainstay in the treatment of many malignancies but also results in collateral obliteration of microvasculature and dermal/subcutaneous fibrosis. Soft tissue reconstruction of hypovascular, irradiated recipient sites through fat grafting remains challenging; however, a coincident improvement in surrounding skin quality has been noted. Cell-assisted lipotransfer (CAL), the enrichment of fat with additional adipose-derived stem cells (ASCs) from the stromal vascular fraction, has been shown to improve fat volume retention, and enhanced outcomes may also be achieved with CAL at irradiated sites. Supplementing fat grafts with additional ASCs may also augment the regenerative effect on radiation-damaged skin. In this study, we demonstrate the ability for CAL to enhance fat graft volume retention when placed beneath the irradiated scalps of immunocompromised mice. Histologic metrics of fat graft survival were also appreciated, with improved structural qualities and vascularity. Finally, rehabilitation of radiation-induced soft tissue changes were also noted, as enhanced amelioration of dermal thickness, collagen content, skin vascularity, and biomechanical measures were all observed with CAL compared to unsupplemented fat grafts. Supplementation of fat grafts with ASCs therefore shows promise for reconstruction of complex soft tissue defects following adjuvant radiotherapy. PMID:26661694

  6. Radiation grafting of pH-sensitive acrylic acid and 4-vinyl pyridine onto nylon-6 using one- and two-step methods

    NASA Astrophysics Data System (ADS)

    Ortega, Alejandra; Alarcón, Darío; Muñoz-Muñoz, Franklin; Garzón-Fontecha, Angélica; Burillo, Guillermina

    2015-04-01

    Acrylic acid (AAc) and 4-vinyl pyridine (4VP) were γ-ray grafted onto nylon-6 (Ny6) films via pre-irradiation oxidative method. These monomers were grafted using a one-step method to render Ny6-g-(AAc/4VP). A two-step or sequential method was used to render (Ny6-g-AAc)-g-4VP. Random copolymer branches were obtained when the grafting was carried out via one-step method using the two monomers together. The two-step method was applied to graft chains of 4VP on both Ny6 substrate and previously grafted AAc chains (Ny6-g-AAc). The two types of binary copolymers synthesized were characterized to determine the amount of grafted polymers, the thermal behavior (DSC and TGA), the surface composition (XPS), and the pH responsiveness. In the two-step process, it is possible to achieve a higher graft yield, better control of the amount of each monomer, good reversibility in the swelling/deswelling process and shorter time to achieve equilibrium swelling.

  7. A Highly Thermostable Ceramic-Grafted Microporous Polyethylene Separator for Safer Lithium-Ion Batteries.

    PubMed

    Zhu, Xiaoming; Jiang, Xiaoyu; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2015-11-01

    The safety concern is a critical obstacle to large-scale energy storage applications of lithium-ion batteries. A thermostable separator is one of the most effective means to construct the safe lithium-ion batteries. Herein, we demonstrate a novel ceramic (SiO2)-grafted PE separator prepared by electron beam irradiation. The separator shows similar thickness and pore structure to the bare separator, while displaying strong dimensional thermostability, as the shrinkage ratio is only 20% even at an elevated temperature of 180 °C. Besides, the separator is highly electrochemically inert, showing no adverse effect on the energy and power output of the batteries. Considering the excellent electrochemical and thermal stability, the SiO2-grafted PE separator developed in this work is greatly beneficial for constructing safer lithium-ion batteries.

  8. Characterization of a subpopulation in neonatal thymus which suppress the graft-vs.-host reaction.

    PubMed

    Van Bekkum, D W; Knaan-Shanzer, S

    1983-05-01

    Thymus cells from neonatal and infant mice were found to have a high capacity to prevent mortality from acute graft-vs.-host disease as compared with spleen cells from stable radiation chimeras. This suppressive capacity of thymocytes decreases with age after birth as was demonstrated by semi-quantitative cell titrations. This suppressor activity is restricted to syngeneity of the graft-vs.-host disease-including cells. The thymic suppressor cells are Thy-1+ and Lyt-1+ and IgG- and IgM-. They do not agglutinate with peanut agglutinin and have a high electrophoretic mobility. In vitro irradiation experiments showed that the suppressor cells are radiation sensitive. These results are compared with the available information on cells suppressing delayed-type hypersensitivity reactions and those suppressing B cell responses.

  9. Subacute radiation dermatitis: a histologic imitator of acute cutaneous graft-versus-host disease

    SciTech Connect

    LeBoit, P.E.

    1989-02-01

    The histopathologic changes of radiation dermatitis have been classified either as early effects (necrotic keratinocytes, fibrin thrombi, and hemorrhage) or as late effects (vacuolar changes at the dermal-epidermal junction, atypical radiation fibroblasts, and fibrosis). Two patients, one exposed to radiation therapeutically and one accidentally, are described. Skin biopsy specimens showed an interface dermatitis characterized by numerous dyskeratotic epidermal cells with lymphocytes in close apposition (satellite cell necrosis); that is, the epidermal changes were similar to those in acute graft-versus-host disease. Because recipients of bone marrow transplants frequently receive total body irradiation as part of their preparatory regimen, the ability of radiation to cause persistent epidermal changes similar to those in acute graft-versus-host disease could complicate the interpretation of posttransplant skin biopsy specimens.

  10. Hypocrellin B graft on activated carbon and photocatalytic oxidation of 2,3,5-trimethylphenol

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Li, Ying; Zhang, Pei; Zhang, Jucheng; Min, Yong; Yi, Zhongzhou; Zhang, Canbang; Wu, Mingzhu; Chen, Rui

    2008-12-01

    Hypocrellin B, a photosensitizer isolated from Hypocrella Bambuase sacc in Yunnan province, has significant anti-tumor and anti-virus character. In this article, hypocrellin B, which was grafted on activated carbon, was used as photocatalysts to catalytic oxidize 2,3,5-trimethylphenol to 2,3,5-trimethylhydrobenzoquinone because of its high photons efficiency. This study realized nearly 100% selectivity for 2,3,5-trimethylhydrobenzoquinone under visible light irradiation (>400nm) at aerobic atmosphere. The photocatalytic oxidation process has been studied by different parameters like the pretreatment of activated carbon, synthetic mehtod of grafted hypocrellin, and photo-assisted oxidation catalysis of 2,3,5-trimethylphenol to 2,3,5-trimethylhdrobenzoquinone. Compared to the conventional methods, this process could be more eco-friendly.

  11. Water dispersible polytetrafluoroethylene microparticles prepared by grafting of poly(acrylic acid)

    NASA Astrophysics Data System (ADS)

    Yang, Changqiao; Xu, Lu; Zeng, Hongyan; Tang, Zhongfeng; Zhong, Lei; Wu, Guozhong

    2014-10-01

    Due to the hydrophobic nature and high gravimetric density, it is very difficult to obtain water dispersible polytetrafluoroethylene (PTFE) powder. In this work, hydrophilic PTFE microparticles were successfully prepared by grafting of poly(acrylic acid) onto PTFE micropowder via a pre-irradiation method. The as-obtained hydrophilic PTFE microparticles were analyzed by FT-IR, 1H NMR, CA, SEM and TGA. After neutralization by sodium hydroxide, the water contact angle decreased from 145.69° for pristine PTFE to 63.38° for PTFE-g-NaAA. The obtained micropowder can be easily dispersed in water to form a dispersion with very high stability. Furthermore, the presence of grafted PAA shows no obvious influence on degradation temperature of PTFE backbones.

  12. Total lymphoid irradiation in heart transplantation: Adjunctive treatment for recurrent rejection

    SciTech Connect

    Frist, W.H.; Winterland, A.W.; Gerhardt, E.B.; Merrill, W.H.; Atkinson, J.B.; Eastburn, T.E.; Stewart, J.R.; Eisert, D.R. )

    1989-12-01

    In the face of recurrent heart transplant graft rejection refractory to all conventional immunotherapy, retransplantation is customary treatment. The case of a heart transplant recipient unsuitable for retransplantation whose recurrent rejection was successfully treated with postoperative total lymphoid irradiation is described.

  13. Swelling properties of cassava starch grafted with poly (potassium acrylate-co-acrylamide) superabsorbent hydrogel prepared by ionizing radiation

    SciTech Connect

    Barleany, Dhena Ria Ulfiyani, Fida; Istiqomah, Shafina; Rahmayetty; Heriyanto, Heri; Erizal

    2015-12-29

    Natural and synthetic hydrophylic polymers can be phisically or chemically cross-linked in order to produce hydrogels. Starch based hydrogels grafted with copolymers from acrylic acid or acrylamide have become very popular for water absorbent application. Superabsorbent hydrogels made from Cassava starch grafted with poly (potassium acrylate-co-acrylamide) were prepared by using of ϒ-irradiation method. Various important parameters such as irradiation doses, monomer to Cassava starch ratio and acrylamide content were investigated. The addition of 7,5 % w w{sup −1} acrylamide into the reaction mixture generated a starch graft copolymer with a water absorption in distilled water as high as 460 g g{sup −1} of its dried weight. The effectivity of hydrogel as superabsorbent for aqueous solutions of NaCl and urea was evaluated. The obtained hydrogel showed the maximum absorptions of 317 g g{sup −1} and 523 g g{sup −1} for NaCl and urea solution, respectively (relative to its own dry weight). The structure of the graft copolymer was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM)

  14. Swelling properties of cassava starch grafted with poly (potassium acrylate-co-acrylamide) superabsorbent hydrogel prepared by ionizing radiation

    NASA Astrophysics Data System (ADS)

    Barleany, Dhena Ria; Ulfiyani, Fida; Istiqomah, Shafina; Heriyanto, Heri; Rahmayetty, Erizal

    2015-12-01

    Natural and synthetic hydrophylic polymers can be phisically or chemically cross-linked in order to produce hydrogels. Starch based hydrogels grafted with copolymers from acrylic acid or acrylamide have become very popular for water absorbent application. Superabsorbent hydrogels made from Cassava starch grafted with poly (potassium acrylate-co-acrylamide) were prepared by using of ϒ-irradiation method. Various important parameters such as irradiation doses, monomer to Cassava starch ratio and acrylamide content were investigated. The addition of 7,5 % w w-1 acrylamide into the reaction mixture generated a starch graft copolymer with a water absorption in distilled water as high as 460 g g-1 of its dried weight. The effectivity of hydrogel as superabsorbent for aqueous solutions of NaCl and urea was evaluated. The obtained hydrogel showed the maximum absorptions of 317 g g-1 and 523 g g-1 for NaCl and urea solution, respectively (relative to its own dry weight). The structure of the graft copolymer was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM).

  15. Planarian Immobilization, Partial Irradiation, and Tissue Transplantation

    PubMed Central

    Guedelhoefer IV, Otto C.; Sánchez Alvarado, Alejandro

    2012-01-01

    The planarian, a freshwater flatworm, has proven to be a powerful system for dissecting metazoan regeneration and stem cell biology1,2. Planarian regeneration of any missing or damaged tissues is made possible by adult stem cells termed neoblasts3. Although these stem cells have been definitively shown to be pluripotent and singularly capable of reconstituting an entire animal4, the heterogeneity within the stem cell population and the dynamics of their cellular behaviors remain largely unresolved. Due to the large number and wide distribution of stem cells throughout the planarian body plan, advanced methods for manipulating subpopulations of stem cells for molecular and functional study in vivo are needed. Tissue transplantation and partial irradiation are two methods by which a subpopulation of planarian stem cells can be isolated for further study. Each technique has distinct advantages. Tissue transplantation allows for the introduction of stem cells, into a naïve host, that are either inherently genetically distinct or have been previously treated pharmacologically. Alternatively, partial irradiation allows for the isolation of stem cells within a host, juxtaposed to tissue devoid of stem cells, without the introduction of a wound or any breech in tissue integrity. Using these two methods, one can investigate the cell autonomous and non-autonomous factors that control stem cell functions, such as proliferation, differentiation, and migration. Both tissue transplantation5,6 and partial irradiation7 have been used historically in defining many of the questions about planarian regeneration that remain under study today. However, these techniques have remained underused due to the laborious and inconsistent nature of previous methods. The protocols presented here represent a large step forward in decreasing the time and effort necessary to reproducibly generate large numbers of grafted or partially irradiated animals with efficacies approaching 100 percent. We

  16. Prosthetic graft interposition of the brachiocephalic veins or superior vena cava combined with resection of malignant tumours: graft patency and risk factors for graft occlusion

    PubMed Central

    Lee, Geun Dong; Choi, Se Hoon; Kim, Yong-Hee; Kim, Dong Kwan; Park, Seung-Il

    2016-01-01

    Background We aimed to assess graft patency in patients undergoing prosthetic graft interposition of the brachiocephalic veins (BCVs) or the superior vena cava (SVC) combined with resection of malignant tumours. Methods A retrospective analysis was conducted on 16 patients who underwent prosthetic graft interposition of the BCVs or the SVC between 1998 and 2012. Results Among a total of 20 grafts in 16 patients (unilateral graft interposition in 12, bilateral graft interposition in 4), 8 grafts were occluded in 8 patients. Overall graft patency rate was 64.6%, 42.4% at the 2- and 5-year follow-up. Graft patency rate of the left BCV was significantly lower than that of the right BCV or the SVC (2-year patency, 38.1% vs. 81.8%, P=0.024). In univariate analysis, the superior anastomosis site [left BCV vs. right BCV; hazard ratio (HR) =2.312; 95% confidence interval (CI), 1.015–5.265; P=0.046], the inferior anastomosis site (right atrial appendage vs. SVC; HR =2.409; 95% CI, 1.124–5.161; P=0.024), and interruption of warfarin (HR =5.015; 95% CI, 1.106–22.734; P=0.037) were significant risk factors for graft occlusion. Graft occlusive symptoms were identified in 4 patients who underwent unilateral graft interposition. Conclusions Prosthetic graft interposition between the left BCV and the right atrial appendage resulted in a significant rate of graft occlusion. Prosthetic graft interposition of the bilateral BCVs and long-term warfarin therapy may be necessary to prevent graft occlusive symptoms. PMID:26904213

  17. Abrogation of hybrid resistance to bone marrow engraftment by graft versus host induced immune deficiency

    SciTech Connect

    Hakim, F.T.; Shearer, G.M.

    1986-03-01

    Lethally irradiated F/sub 1/ mice, heterozygous at the hematopoietic histocompatibility (Hh) locus at H-2D/sup b/, reject bone marrow grafts from homozygous H-2/sup b/ parents. This hybrid resistance (HR) is reduced by prior injection of H-2/sup b/ parental spleen cells. Since injection of parental spleen cells produces a profound suppression of F/sub 1/ immune functions, the authors investigated whether parental-induced abrogation of HR was due to graft-vs-host induced immune deficiency (GVHID). HR was assessed by quantifying engraftment in irradiated mice using /sup 125/I-IUdR spleen uptake; GVHID by measuring generation of cytotoxic T lymphocytes (CTL) from unirradiated mice. They observed correlation in time course, spleen dose dependence and T cell dependence between GVHID and loss of HR. The injection of B10 recombinant congenic spleens into (B10 x B10.A) F/sub 1/ mice, prior to grafting with B10 marrow, demonstrated that only those disparities in major histocompatibility antigens which generated GVHID would result in loss of HR. Spleens from (B10 x B10.A(2R))F/sub 1/ mice (Class I disparity only) did not induce GVHID or affect HR, while (B10 x B10.A(5R)F/sub 1/ spleens (Class I and II disparity) abrogated CTL generation and HR completely. GVHID produced by a Class II only disparity, as in (B10 x B10.A(5R))F/sub 1/ spleens injected into (B6/sup bm12 x B10.A(5R))F/sub 1/ mice, was also sufficient to markedly reduce HR to B10 bone marrow. Modulation of hematopoietic graft rejection by GVHID may affect marrow engraftment in man.

  18. Impact of radiation therapy on healing and stability of vascularized bone grafts in a dog model.

    PubMed

    Eisenschenk, Andreas; Witzel, Christiane; Lautenbach, Martin; Ekkernkamp, Axel; Weber, Ulrich; Küntscher, Markus V

    2006-01-01

    The purpose of the study was to observe the impact of radiation therapy on healing and biomechanical properties of vascularized bone grafts, and thus to establish an appropriate large animal model. Ten male beagles were divided into two experimental groups: radiation (R) and control (C). The left 5th to 7th ribs of the animals of group R were irradiated 3 and 2 weeks preoperatively, using a dose of 8 Gy each time. Each animal of both groups underwent the following operative procedures. The 5th and 7th ribs were removed, and the 5th rib was replaced by a vascularized pedicle transfer of the 4th rib. The 7th rib was reconstructed using a pedicle transplant of the 8th rib. The 5th and 7th ribs were used as nonvascularized bone grafts to replace the donor sites of the 4th and 8th ribs, respectively. Group R received two further irradiation cycles 2 and 3 weeks postoperatively. The vascularized rib grafts of group R demonstrated a higher number of delayed unions in plain x-rays and avascular bone segments in microangiography than the control group. The presence of vital osteocytes in histology was not significantly different between groups. Biomechanical tests focusing on the durability of vascularized ribs against bending and torsion forces demonstrated a reduction of average maximum bending moments by 56.6% after radiation compared to controls (P < 0.05). Twisting moments were reduced by 47.6% (P < 0.05). The data demonstrate a significant worsening in bone healing and stability after pre- and postoperative radiation therapy to the wound bed and bone grafts. Thus, a large animal model is established for further determination of different strategies of radiotherapy in combination with vascularized bone transfers.

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

    PubMed Central

    Shimizu, Yusuke; Ihara, Jyun; Kishi, Kazuo

    2016-01-01

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

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

    SciTech Connect

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

    2010-02-15

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Allogenous cartilage graft versus autogenous cartilage graft in augmentation rhinoplasty: a decade of clinical experience.

    PubMed

    Tosun, Z; Karabekmez, F E; Keskin, M; Duymaz, A; Savaci, N

    2008-03-01

    Cartilage grafts have great value in augmentation rhinoplasty. For most surgeons, an autogenous cartilage graft is the first choice in rhinoplasty because of its resistance to infection and resorption. On the other hand, an allogenous cartilage graft might be preferred over an autogenous graft to avoid additional morbidity and lengthened operating time. Allogenous cartilage grafts not only have the advantage of averting donor site morbidity but also are resistant to infection, resembling autogenous cartilage grafts. The authors present their experience with 41 patients who underwent augmentation rhinoplasty using 22 autogenous and 19 allogenous cartilage grafts between June 1994 and August 2004. For evaluation of adequate augmentation rates, photographic analyses were performed on preoperative, early postoperative, and late postoperative photographs from all the patients. To assess patient satisfaction, the Facial Appearance Sorting Test (FAST) was applied preoperatively and late postoperatively in both groups. These results were compared, and it was concluded that in terms of resorption, there was no difference in the early and late postoperative follow-up data between allogenous and autogenous cartilage grafts. Evaluation of the preoperative and early postoperative photographic outcomes showed statistically significant differences with respect to adequate augmentation rates between the two groups. The FAST scores showed statistically significant differences between preoperative and late postoperative outcomes. There were no infections in the two groups of patients.

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

    PubMed Central

    Shimizu, Yusuke; Ihara, Jyun; Kishi, Kazuo

    2016-01-01

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

  4. Physical properties of agave cellulose graft polymethyl methacrylate

    SciTech Connect

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

    2013-11-27

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

  5. Physical properties of agave cellulose graft polymethyl methacrylate

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  6. Protein Adsorption on Surfaces with Grafted Polymers

    PubMed Central

    Szleifer, I.

    1997-01-01

    A general theoretical framework for studying the adsorption of protein molecules on surfaces with grafted polymers is presented. The approach is a generalization of the single-chain mean-field theory, in which the grafted polymer-protein-solvent layer is assumed to be inhomogeneous in the direction perpendicular to the grafting surface. The theory enables the calculation of the adsorption isotherms of the protein as a function of the surface coverage of grafted polymers, concentration of protein in bulk, and type of solvent molecules. The potentials of mean force of the protein with the surface are calculated as a function of polymer surface coverage and amount of protein adsorbed. The theory is applied to model lysozyme on surfaces with grafted polyethylene oxide. The protein is modeled as spherical in solution, and it is assumed that the protein-polymer, protein-solvent, and polymer-solvent attractive interactions are all equal. Therefore, the interactions determining the structure of the layer (beyond the bare polymer-surface and protein-surface interactions) are purely repulsive. The bare surface-protein interaction is taken from atomistic calculations by Lee and Park. For surfaces that do not have preferential attractions with the grafted polymer segments, the adsorption isotherms of lysozyme are independent of the polymer length for chains with more than 50 ethylene oxide units. However, the potentials of mean force show strong variations with grafted polymer molecular weight. The competition between different conformations of the adsorbed protein is studied in detail. The adsorption isotherms change qualitatively for surfaces with attractive interactions with ethylene oxide monomers. The protein adsorption is a function of chain length—the longer the polymer the more effective it is in preventing protein adsorption. The structure of the layer and its deformation upon protein adsorption are very important in determining the adsorption isotherms and the

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

    PubMed Central

    2013-01-01

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

  8. Radiation-induced graft copolymerization of poly(ethylene glycol) monomethacrylate onto deoxycholate-chitosan nanoparticles as a drug carrier

    NASA Astrophysics Data System (ADS)

    Pasanphan, Wanvimol; Rattanawongwiboon, Thitirat; Rimdusit, Pakjira; Piroonpan, Thananchai

    2014-01-01

    Poly(ethylene glycol) monomethacrylate-grafted-deoxycholate chitosan nanoparticles (PEGMA-g-DCCSNPs) were successfully prepared by radiation-induced graft copolymerization. The hydrophilic poly(ethylene glycol) monomethacrylate was grafted onto deoxycholate-chitosan in an aqueous system. The radiation-absorbed dose is an important parameter on degree of grafting, shell thickness and particle size of PEGMA-g-DCCSNPs. Owing to their amphiphilic architecture, PEGMA-g-DCCSNPs self-assembled into spherical core-shell nanoparticles in aqueous media. The particle size of PEGMA-g-DCCSNPs measured by TEM varied in the range of 70-130 nm depending on the degree of grafting as well as the irradiation dose. Berberine (BBR) as a model drug was encapsulated into the PEGMA-g-DCCSNPs. Drug release study revealed that the BBR drug was slowly released from PEGMA-g-DCCSNPs at a mostly constant rate of 10-20% in PBS buffer (pH 7.4) at 37 °C over a period of 23 days.

  9. Iliac Bone Grafting of the Intact Glenoid Improves Shoulder Stability with Optimal Graft Positioning

    PubMed Central

    Willemot, Laurent B.; Eby, Sarah F.; Thoreson, Andrew R.; Debeer, Phillipe; Victor, Jan; An, Kai-Nan; Verborgt, Olivier

    2014-01-01

    Background Bone grafting procedures are increasingly popular for the treatment of anterior shoulder instability. In cases with high risk of recurrence, open coracoid transplantation is preferred but can be technically demanding. Free bone graft glenoid augmentation may be an alternative strategy for high-risk patients without significant glenoid bone loss. This biomechanical cadaver study aims to assess the stabilizing effect of free iliac crest bone grafting of the intact glenoid and the importance of sagittal graft position. Methods Eight fresh frozen cadaver shoulders were tested. The bone graft was fixed on the glenoid neck at three sagittal positions (50%, 75% and 100% below the glenoid equator). Displacement and reaction force were monitored with a custom device while translating the humeral head over the glenoid surface in both anterior and antero-inferior direction. Results Peak force (PF) increased significantly from the standard labral repair to the grafted conditions in both anterior (14.7 (±5.5 N) vs. 27.3 (±6.9 N)) and antero-inferior translation (22.0 (±5.3 N) vs. 29.3 (±6.9 N)). PF was significantly higher for the grafts at the 50% and 75% positions, compared to the grafts 100% below the equator with anterior translation. Antero-inferior translation resulted in significantly higher values for the 100% and 75% positions compared to the 50% position. Conclusions This biomechanical study confirms improved anterior glenohumeral stability after iliac crest bone graft augmentation of the anterior glenoid. The results also demonstrate the importance of bone graft position in the sagittal plane, with the ideal position determined by the direction of dislocation. PMID:25457786

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

    SciTech Connect

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

    2008-09-15

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

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

    SciTech Connect

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

    2011-08-15

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

  12. Current use of biologic graft extenders for spinal fusion.

    PubMed

    Coseo, N M; Saldua, N; Harrop, J

    2012-09-01

    Use of biologic graft extenders in spinal fusions is increasing. Multiple allograft alternatives exist to the "gold-standard" autologous bone grafting. The ideal graft extender is osteoconductive, osteoinductive and has osteogenic potential. While the ideal graft extender has yet to be found, available bone graft extenders have varying degrees of predominantly osteoconductive and osteoinductive properties. This review will provide an update on available graft extenders including bone morphogenetic proteins, mesenchymal stem cells, and demineralized bone matrix. The goal is to provide a review of the current use in spinal fusions and future directions in biologics for spinal fusion.

  13. Onlay Bone Grafts in Head and Neck Reconstruction

    PubMed Central

    Yazar, Sukru

    2010-01-01

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

  14. Anterior Cruciate Ligament Graft Choices: A Review of Current Concepts

    PubMed Central

    Dheerendra, Sujay K; Khan, Wasim S; Singhal, Rohit; Shivarathre, Deepak G; Pydisetty, Ravi; Johnstone, David

    2012-01-01

    The graft choice for anterior cruciate ligament (ACL) reconstruction continues to be controversial. There are several options available for the treating surgeon, including Bone Patellar Tendon Bone (BPTB) grafts, Hamstring tendon (HT) grafts, allografts and synthetic grafts. Within the last decade there have been several comparative trials and meta-analysis, which have failed to provide an answer with regards to the best graft available. The aim of this review is to understand the current concepts in graft choices for ACL reconstruction. PMID:22888379

  15. Imaging characteristics of bone graft materials.

    PubMed

    Beaman, Francesca D; Bancroft, Laura W; Peterson, Jeffrey J; Kransdorf, Mark J; Menke, David M; DeOrio, James K

    2006-01-01

    Bone graft materials are widely used in reconstructive orthopedic procedures to promote new bone formation and bone healing, provide a substrate and scaffolding for development of bone structure, and function as a means for direct antibiotic delivery. Bone graft materials include autografts, allografts, and synthetic substitutes. An autograft (from the patient's own bone) supplies both bone volume and osteogenic cells capable of new bone formation. The imaging appearance of an autograft depends on its type, composition, and age. Autografts often appear as osseous fragments at radiography. At computed tomography (CT), autografts appear similar to the adjacent cortical bone. At magnetic resonance (MR) imaging, however, autografts have a variable appearance as a consequence of the viable marrow inside them, a feature not present in other graft materials. An allograft (from cadaveric bone) has an appearance similar to that of cortical bone on radiographs and CT images. An allograft in the form of bone chips or morsels does not show those features on radiographs and CT images, but instead appears as a conglomerate with medium to high opacity and attenuation within the bone defect. In the immediate postoperative period, allografts appear hypointense on both T1- and T2-weighted MR images. Hematopoietic tissue replaces the normal fatty marrow in the later phases of graft incorporation. Synthetic bone substitutes are much more variable in imaging appearance. As the use of bone allografts and synthetic substitutes increases, familiarity with postoperative imaging features is essential for differentiation between grafts and residual or recurrent disease.

  16. Vascularized tail bone grafts in rats.

    PubMed

    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.

  17. Pretransplant Mobilization with Granulocyte Colony-Stimulating Factor Improves B-Cell Reconstitution by Lentiviral Vector Gene Therapy in SCID-X1 Mice

    PubMed Central

    Huston, Marshall W.; Riegman, Adriaan R.A.; Yadak, Rana; van Helsdingen, Yvette; de Boer, Helen; van Til, Niek P.

    2014-01-01

    Abstract Hematopoietic stem cell (HSC) gene therapy is a demonstrated effective treatment for X-linked severe combined immunodeficiency (SCID-X1), but B-cell reconstitution and function has been deficient in many of the gene therapy treated patients. Cytoreductive preconditioning is known to improve HSC engraftment, but in general it is not considered for SCID-X1 since the poor health of most of these patients at diagnosis and the risk of toxicity preclude the conditioning used in standard bone marrow stem cell transplantation. We hypothesized that mobilization of HSC by granulocyte colony-stimulating factor (G-CSF) should create temporary space in bone marrow niches to improve engraftment and thereby B-cell reconstitution. In the present pilot study supplementing our earlier preclinical evaluation (Huston et al., 2011), Il2rg−/− mice pretreated with G-CSF were transplanted with wild-type lineage negative (Lin−) cells or Il2rg−/− Lin− cells transduced with therapeutic IL2RG lentiviral vectors. Mice were monitored for reconstitution of lymphocyte populations, level of donor cell chimerism, and antibody responses as compared to 2 Gy total body irradiation (TBI), previously found effective in promoting B-cell reconstitution. The results demonstrate that G-CSF promotes B-cell reconstitution similar to low-dose TBI and provides proof of principle for an alternative approach to improve efficacy of gene therapy in SCID patients without adverse effects associated with cytoreductive conditioning. PMID:25222508

  18. Commercial food irradiation

    SciTech Connect

    Black, E.F.; Libby, L.M.

    1983-06-01

    Food irradiation is discussed. Irradiation exposes food to gamma rays from a cobalt-60 or a cesium-137 source, or to high-energy electrons emitted by an electron accelerator. A major advantage is that food can be packaged either before or after treatment. FDA regulations with regard to irradiation are discussed. Comments on an 'Advance Notice' on irradiation, published by the FDA in 1981 are summarized.

  19. High-energy radiation processing, a smart approach to obtain PVP-graft-AA nanogels

    NASA Astrophysics Data System (ADS)

    Grimaldi, N.; Sabatino, M. A.; Przybytniak, G.; Kaluska, I.; Bondì, M. L.; Bulone, D.; Alessi, S.; Spadaro, G.; Dispenza, C.

    2014-01-01

    Poly(N-vinylpyrrolidone)-grafted-acrylic acid biocompatible nanogels (NGs) were prepared using an exiting industrial-type electron accelerator and setups, starting from semi-dilute aqueous solutions of a commercial PVP and the acrylic acid monomer. As a result, NGs with tunable size and structure can be obtained quantitatively. Sterility was also imparted at the integrated dose absorbed. The chemical structure of the NGs produced was confirmed through Fourier Transformer Infrared Spectroscopy (FT-IR). The molecular and physico-chemical properties of NGs, such as the hydrodynamic dimensions and surface charge densities, for various polymer and monomer concentrations in the irradiated solutions, are discussed here.

  20. Positronium Formation Of Glyeisdyl Methacrylic Acid (GMA)/Styrene Grafted On PVDF Membrane For Fuel Cells

    SciTech Connect

    Abdel-Hady, E. E.; Abdel-Hamed, M. O.; Eltonny, M. M.

    2011-06-01

    Simultaneous gamma irradiation was used effectively for grafting of glycidyl methacrylic acid and styrene onto Poly vinyldine fluoride (PVDF). Membranes were characterized by thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). The properties of the obtained membranes were evaluated in terms of proton conductivity, methanol permeability and positron annihilation lifetime (PALS) parameters. The high probability of Positronium formation enables the application of PALS to the study of free volume. Good property values approved the applicability of the membrane from the cost benefit point of view.

  1. Effect of irradiation on the prevulcanized latex/low nitrosamines latex blends

    SciTech Connect

    Ibrahim, Pairu; Zin, Wan Manshol Wan; Daik, Rusli

    2015-09-25

    Radiation Prevulcanized Natural Rubber Latex (RVNRL) was blended with Low Nitrosamines Latex (LNL) at different composition ratio. Methyl Metachrylate (MMA) was added for grafting onto the blended latex. Blended latex was subjected to gamma irradiation at various doses up to 8kGy. The mechanical properties and FTIR analysis were investigated as a function of the blended composition and irradiation dose. It was found that blending at specific ratio and gamma irradiation at specific dose led to significant improvement on the properties of the latex. The optimum mechanical properties was attained at a total blending ratio of 70% RVNRL and 30% of LNL.

  2. Effect of gamma irradiation on mechanical properties of human cortical bone: influence of different processing methods.

    PubMed

    Kaminski, Artur; Jastrzebska, Anna; Grazka, Ewelina; Marowska, Joanna; Gut, Grzegorz; Wojciechowski, Artur; Uhrynowska-Tyszkiewicz, Izabela

    2012-08-01

    The secondary sterilisation by irradiation reduces the risk of infectious disease transmission with tissue allografts. Achieving sterility of bone tissue grafts compromises its biomechanical properties. There are several factors, including dose and temperature of irradiation, as well as processing conditions, that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect of gamma irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as gamma irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress-strain curves examined by univariate analysis are described. Based on multivariate analysis it was found that defatting of bone rings had no significant effect on any mechanical parameter studied, whereas irradiation with both doses decreased significantly the ultimate strain and its derivative toughness. The elastic limit and resilience were significantly increased by irradiation with the dose 25 kGy, but not 35 kGy, when the time of irradiation was longer. Additionally, irradiation at ambient temperature decreased maximum load, elastic limit, resilience, and ultimate stress. As strain in the elastic region was not affected, decreased elastic limit resulted in lower resilience. The opposite phenomenon was observed in the plastic region, where in spite of the lower ultimate stress, the toughness was increased due to the

  3. Proteomics analysis of compatibility and incompatibility in grafted cucumber seedlings.

    PubMed

    Xu, Qing; Guo, Shi-Rong; Li, Lin; An, Ya-Hong; Shu, Sheng; Sun, Jin

    2016-08-01

    Graft compatibility between rootstock and scion is the most important factor influencing the survival of grafted plants. In this study, we used two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF MS) to investigate differences in leaf proteomes of graft-compatible and graft-incompatible cucumber (Cucumis sativus L.)/pumpkin (Cucurbita L.) combinations. Cucumber seedlings were used as the scions and two pumpkin cultivars with strongly contrasting grafting compatibilities were used as the rootstocks. Non-grafted and self-grafted cucumber seedlings served as control groups. An average of approximately 500 detectable spots were observed on each 2-DE gel. A total of 50 proteins were differentially expressed in response to self-grafting, compatible-rootstock grafting, and incompatible-rootstock grafting and were all successfully identified by MALDI-TOF/TOF MS. The regulation of Calvin cycle, photosynthetic apparatus, glycolytic pathway, energy metabolism, protein biosynthesis and degradation, and reactive oxygen metabolism will probably contribute to intensify the biomass and photosynthetic capacity in graft-compatible combinations. The improved physiological and growth characteristics of compatible-rootstock grafting plants are the result of the higher expressions of proteins involved in photosynthesis, carbohydrate and energy metabolism, and protein metabolism. At the same time, the compatible-rootstock grafting regulation of stress defense, amino acid metabolism, and other metabolic functions also plays important roles in improvement of plant growth. PMID:27070289

  4. Long-term cognitive effects of human stem cell transplantation in the irradiated brain

    PubMed Central

    Acharya, Munjal M.; Martirosian, Vahan; Christie, Lori-Ann; Limoli, Charles L.

    2016-01-01

    Purpose Radiotherapy remains a primary treatment modality for the majority of central nervous system tumors, but frequently leads to debilitating cognitive dysfunction. Given the absence of satisfactory solutions to this serious problem, we have used human stem cell therapies to ameliorate radiation-induced cognitive impairment. Here, past studies have been extended to determine whether engrafted cells provide even longer-term benefits to cognition. Materials and methods Athymic nude rats were cranially irradiated (10 Gy) and subjected to intrahippocampal transplantation surgery 2 days later. Human embryonic stem cells (hESC) or human neural stem cells (hNSC) were transplanted, and animals were subjected to cognitive testing on a novel place recognition task 8 months later. Results Grafting of hNSC was found to provide long lasting cognitive benefits over an 8-month post-irradiation interval. At this protracted time, hNSC grafting improved behavioral performance on a novel place recognition task compared to irradiated animals not receiving stem cells. Engrafted hESC previously shown to be beneficial following a similar task, 1 and 4 months after irradiation, were not found to provide cognitive benefits at 8 months. Conclusions Our findings suggest that hNSC transplantation promotes the long-term recovery of the irradiated brain, where intrahippocampal stem cell grafting helps to preserve cognitive function. PMID:24882389

  5. Fludarabine Allows Dose Reduction for Total Body Irradiation in Pediatric Hematopoietic Stem Cell Transplantation

    SciTech Connect

    Kornguth, David G. . E-mail: dkorngut@mdanderson.org; Mahajan, Anita; Woo, Shiao; Chan, Ka Wah; Antolak, John; Ha, Chul S.

    2007-07-15

    Purpose: To examine, in the setting of total body irradiation (TBI) for the preparation of pediatric hematopoietic stem cell transplantation (HSCT), whether TBI dose can be reduced without compromising the efficacy of a regimen consisting of fludarabine and radiotherapy; and whether there is any increased risk of pulmonary toxicity due to the radiosensitizing effect of fludarabine. Methods and Materials: A total of 52 pediatric patients with hematologic malignancies received TBI-based conditioning regimens in preparation for allogeneic HSCT. Twenty-three patients received 12 Gy in 4 daily fractions in combination with cyclophosphamide, either alone or with other chemotherapeutic and biologic agents. Twenty-nine patients received 9 Gy in 3 fractions in conjunction with fludarabine and melphalan. Clinical and radiation records were reviewed to determine engraftment, pulmonary toxicity (according to Radiation Therapy Oncology Group criteria), transplant-related mortality, recurrence of primary disease, and overall survival. Results: The two groups of patients had comparable pretransplant clinical characteristics. For the 12-Gy and 9-Gy regimens, the engraftment (89% and 93%; p = 0.82), freedom from life-threatening pulmonary events (65% and 79%; p = 0.33), freedom from relapse (60% and 73%; p = 0.24), and overall survival (26% and 47%; p = 0.09) were not statistically different. Conclusions: The addition of fludarabine and melphalan seems to allow the dose of TBI to be lowered to 9 Gy without loss of engraftment or antitumor efficacy.

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

    PubMed

    Cruz-Navarro, Natalio; León-Dueñas, Eduardo

    2014-01-01

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

  7. Fragility-Controllable Polymer Grafted Nanoparticles

    NASA Astrophysics Data System (ADS)

    Asai, Makoto; Kumar, Sanat; Cacciuto, Angelo

    20 years ago, the concept of `Fragility' has been suggested to categorize glass-forming liquids. Currently, we know there are two kinds of glass-forming liquids group. One is Arrhenius type liquids called as Strong glass (large Fragility). Another one is non-Arrhenius liquid called as Fragile glass (small Fragility). The physical meaning of Fragility is unknown yet, but people believe that to understand the physical meaning of Fragility leads to understand glass transition. Recently we found Polymer Grafted Nanoparticles (PGNPs) could behave like glass-forming liquids depending on their grafting density in MD simulations. Surprisingly, their Fragility can be controlled by grafting density and we can obtain both `Strong' and `Fragile' glass using this system. The authors thank the National Science Foundation for financial support of this work. AC acknowledges financial supported from the National Science Foundation under CAREER Grant No. DMR-0846426.

  8. A study of paired necro kidney grafts.

    PubMed

    Lamm, L U

    1979-01-01

    The comparison of the fate of kidney pairs originating from the same donor offers an opportunity to control variability in primary kidney graft survival due to characteristics of the donor. The present study on 1,303 pairs was made possible by combining the information in the Scandiatransplant registry and the EDTA follow-up file. The analysis showed that, contrary to expectation, the main variability in kidney graft survival is not donor dependent but rather due to post-nephrectomy factors. By the present approach it was possible to demonstrate a significant effect of presensitisation, HLA-A,B matching and recipient age. In contrast, transportation, and differences in sex and ABO blood group combinations seem to be of no importance for kidney graft survival.

  9. Modeling heterogeneous polymer-grafted nanoparticle networks

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Mbanga, Badel; Yashin, Victor; Balazs, Anna

    Via a dynamic 3D computational approach, we simulate the heterogeneous polymer-grafted nanoparticle networks. The nanoparticles rigid cores are decorated with a corona of grafted polymers, which contain reactive functional groups at the chain ends. With the overlap of grafted polymers, these reactive groups can form weak labile bonds, which can reform after breakage, or stronger bonds, which rupture irreversibly and thus, the nanoparticles are interconnected by dual cross-links. Previous work has been done on homogeneous networks, while we introduce the heterogeneity by considering two types of particles having different reactive functional groups, so that the labile bond energy varies depending on types of the two end reactive groups. We study the effect of tensile and rotational deformations on the network morphology, and observe, in particular, the phase separation of two types of particles. Our results will provide guidelines for designing transformable material that can controllably change structure under mechanical action.

  10. COLD-PLASMA ASSISTED GRAFTING OF PAPER

    SciTech Connect

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

    2008-08-28

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

  11. Graft preservation solutions in cardiovascular surgery.

    PubMed

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

    2016-08-01

    Vein grafts are still the most commonly used graft material in cardiovascular surgery and much effort has been spent in recent years on investigating the optimal harvesting technique. One other related topic of similar importance remained more or less an incidental one. The storage solutions of vein grafts following procurement and prior to implantation are, despite their assumed impact, a relatively neglected theme. There is no doubt that the endothelium plays a key role in long-term patency of vein grafts, but the effects of the different storage solutions on the endothelium remain unclear : In a review of the literature, we could find 20 specific papers that addressed the question, of which the currently available preservation solutions are superior, harmless, damaging or ineffective. The focus lies on saline and autologous whole blood. Besides these two storage media, novel or alternative solutions have been investigated with surprising findings. In addition, a few words will be spent on potential alternatives and novel solutions on the market. As there is currently no randomized clinical trial regarding saline versus autologous whole blood available, this review compares all previous studies and methods of analysis to provide a certain level of evidence on this topic. In summary, saline has negative effects on the endothelial layers and therefore may compromise graft patency. Related factors, such as distension pressure, may outbalance the initial benefit of autologous whole blood or storage solutions and intensify the harmful effects of warm saline. In addition, there is no uniform consent on the superiority of autologous whole blood for vein graft storage. This may open the door to alternatives such as the University of Wisconsin solution or one of the specific designed storage solutions like TiProtec™ or Somaluthion™. Whether these preservation solutions are superior or advantageous remains the subject of further studies. PMID:27068248

  12. Prophylactic antibiotics prevent bacterial biofilm graft infection.

    PubMed

    Bergamini, T M; Peyton, J C; Cheadle, W G

    1992-02-01

    Bacterial biofilm graft infection is due to prostheses colonization by Staphylococcus epidermidis, a pathogen frequently recovered from perigraft tissues of man during vascular procedures despite the use of asepsis and prophylactic antibiotics. The effect of preoperative intraperitoneal cefazolin, administered at a standard (15 or 30 mg/kg) and high (120 mg/kg) dose, on the prevention of bacterial biofilm infection was studied in a rat model. Seventy-four Dacron grafts, colonized in vitro with S. epidermidis to produce an adherent biofilm (3.19 +/- 0.71 x 10(7) colony-forming units/cm2 graft), were implanted in the dorsal subcutaneous tissue at 0.5, 2, and 4 hr after antibiotic administration. The study strain was a slime-producing clinical isolate with minimum inhibitory concentration (MIC) of 15-30 micrograms/ml to cefazolin. Subcutaneous tissue antibiotic levels were determined at each time interval. One week after implantation, the concentration of bacteria in the surface biofilm by quantitative agar culture was significantly decreased (P less than 0.05) only for grafts implanted when antibiotic tissue levels were greater than or equal to the MIC of the study strain. The result of no growth by biofilm broth culture was significantly achieved (P less than 0.01) only for grafts implanted 0.5 hr after high dose cefazolin, in which the tissue antibiotic level was above the MIC of the study strain. Antibiotics can markedly reduce the bacteria concentration of a prosthetic surface biofilm. The effectiveness of prophylactic antibiotics on the prevention of graft infection is dependent upon maintaining an adequate antibiotic level in the perigraft tissues for the duration of the procedure.

  13. Cantilever rib grafting in salvage rhinoplasty.

    PubMed

    Shubailat, Ghaith F

    2003-01-01

    Loss of nasal skeletal support, whether congenital, following trauma or secondary to multiple failed surgeries, calls for reconstruction aiming at restoring rigid dorsal stability, maintaining tip projection, and restoring respiratory function. Where septal and conchal grafts are inadequate to be used as building blocks, our procedure of choice has been the cantilever osseocartilagenous rib graft with microscrew fixation. In the past 10 years, 48 patients were candidates for this salvage procedure. Long-term functional and cosmetic results have been highly satisfactory. PMID:15058550

  14. Conduits for Coronary Bypass: Vein Grafts

    PubMed Central

    Farkas, Emily A

    2012-01-01

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

  15. Aortic wraps a modification to aortic grafting.

    PubMed

    Gordon, J A

    1989-09-01

    Aortic wrapping has been attempted on occasion when the standard replacement of a diseased lower third of the aorta by a trouser graft is not feasible. Cellophane has been the most common agent employed, but these wraps have met with minimal success and on occasion has even been passed rectally. Kartchner and Lovett have reviewed the techniques and results of the later procedures replacing the cellophane wraps. In most instances a Dacron sheet was utilized. Six cases are reviewed from a solo private practice in which a standard trouser graft replacement was varied by using an alternative form of wrapping.

  16. Conduits for coronary bypass: vein grafts.

    PubMed

    Barner, Hendrick B; Farkas, Emily A

    2012-10-01

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

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

    SciTech Connect

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

    1982-11-01

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

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

    PubMed

    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.

  19. Prolonged heart xenograft survival using combined total lymphoid irradiation and cyclosporine

    SciTech Connect

    Knechtle, S.J.; Halperin, E.C.; Saad, T.; Bollinger, R.R.

    1986-05-01

    Total lymphoid irradiation and cyclosporine have profound immunosuppressive properties and permit successful heart allotransplantation. Cyclosporine used alone has not permitted consistently successful transplantation between species in all cases. Total lymphoid irradiation has not been applied to xenotransplantation. The efficacy of total lymphoid irradiation alone and in combination with cyclosporine was examined using an animal model of heart xenotransplantation. Heterotopic heart transplants were performed using inbred Syrian hamsters as donors and Lewis rats as recipients. Total lymphoid irradiation was administered preoperatively over 3 weeks for a total dose of 15 gray. Cyclosporine was started on the day of surgery and was given as a daily intramuscular injection of 2.5, 5, or 10 mg/kg/day until rejection was complete. Neither total lymphoid irradiation nor cyclosporine alone markedly prolonged graft survival. However, combined total lymphoid irradiation and cyclosporine, 5 or 10 mg/kg/day, dramatically prolonged graft survival to greater than 100 days in most recipients. There were no treatment-related deaths. In conclusion, combined total lymphoid irradiation and cyclosporine permit successful long-term survival of heart xenotransplants in this hamster-to-rat model.

  20. Dyed acrylic-acid grafted polypropylene films for high-dose radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Abdel-Fattah, A. A.; Said, F. I. A.; Ebraheem, S.; El-Kelany, M.; El Miligy, A. A.

    1999-03-01

    Gamma radiation-induced polymerization of acrylic acid (AAc) onto polypropylene (PP) film has been carried out under nitrogen atmosphere. The grafted film of PP-g-PAAc was allowed to react with solutions of two ionic dyes, namely malachite green (MALG) or methylene green (METG). The investigations show that these new dosimeter films of PPMALG and PPMETG may be useful for high-dose gamma radiation applications. The useful absorbed dose range of the dyed films extends up to about 400 kGy, with a minimum useful dose of about 5 kGy. The radiation-induced colour bleaching has been analyzed with visible spectrophotometry, either at the maximum of the absorption band peaking at 601 nm (for PPMETG) or that peaking at 623 nm for (PPMALG). The effects of relative humidity during irradiation, shelf-life and post-irradiation storage in dark and indirect daylight conditions on dosimeters performance are discussed.

  1. 21 CFR 870.3450 - Vascular graft prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vascular graft prosthesis. 870.3450 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3450 Vascular graft prosthesis. (a) Identification. A vascular graft prosthesis is an implanted device intended to...

  2. Defense mechanisms involved in disease resistance of grafted vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Immobilization of peroxidase on SPEU film via radiation grafting

    NASA Astrophysics Data System (ADS)

    Hongfei, Ha; Guanghui, Wang; Jilan, Wu

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

  4. The natural history of bacterial biofilm graft infection.

    PubMed

    Bergamini, T M; Corpus, R A; Brittian, K R; Peyton, J C; Cheadle, W G

    1994-05-01

    A mouse model was developed to study the natural history of vascular prosthetic graft infection due to Staphylococcus epidermidis. Graft infections were established in the back subcutaneous tissue of 46 mice by implantation of Dacron prostheses colonized in vitro with slime-producing S. epidermidis to form an adherent bacterial biofilm [1.7 x 10(7) colony forming units (CFU)/cm2 graft]. Control animals (n = 16) had implantation of sterile Dacron prostheses. None of the control animals developed a graft infection or graft-cutaneous sinus tract. All study animals developed a biofilm graft infection with typical anatomic (perigraft abscess), microbiologic (low bacterial concentration in surface biofilm), and immunologic (normal white blood count) characteristics. A graft-cutaneous sinus tract developed in a significantly higher number of mice with infected grafts by 8-10 weeks (9 of 21) compared to infected grafts explanted at 2 and 4-6 weeks (1 of 25, P < 0.01) and controls (0 of 16, P < 0.03). By 8-10 weeks, 2 animals had no signs of graft infection and the S. epidermidis study strain was not recoverable from 7 grafts. The natural history of bacterial biofilm vascular prostheses infection in the mouse model was similar to that in man, provoking a chronic inflammatory process curiously presenting as a perigraft abscess or graft-cutaneous sinus tract.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    SciTech Connect

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

    2007-02-15

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

  7. Grafting functional antioxidants on highly crosslinked polyethylene

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  8. Fatal Saccharomyces Cerevisiae Aortic Graft Infection

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  9. Prefabricated Composite Graft for Eyelid Reconstruction.

    PubMed

    Nicoletti, Giovanni; Jaber, Omar; Tresoldi, Marco Mario; Pellegatta, Tommaso; Faga, Angela

    2015-10-01

    The authors propose a prefabricated chondromucosal composite graft to reconstruct full-thickness defects of the lower eyelid. The technique was used in a patient suffering from a locally invasive basal cell carcinoma of the lower eyelid, who had previously undergone an extensive submucosal nasal septum resection. One week prior to the eyelid resection, the anterior skin surface of the auricular concha was replaced with a full-thickness oral mucosa graft. One week later, a full-thickness excision of the right lower eyelid was performed and the prefabricated chondromucosal auricular graft was used to restore the posterior lamella. The anterior lamella was reconstructed with a bipedicled myocutaneous flap from the upper eyelid. Because of the patient's scheduling needs, the medial pedicle of the flap was divided 28 days later and the lateral one after further 37 days. All the procedures were performed under local anesthesia. This technique adds a simple key detail to other time-honored reliable techniques, thus outlining an extremely convenient sequence for full-thickness eyelid reconstruction. The easily prepared prefabricated chondromucosal graft might be associated with any of the previously described flaps, thus providing a versatile and reliable method of posterior lamella reconstruction. PMID:26579869

  10. Ultrastable Mesoporous Aluminosilicates by Grafting Routes.

    PubMed

    Mokaya

    1999-10-01

    A combination of postsynthesis grafting and hydrothermal treatment offers an excellent route for the synthesis of ultrastable mesoporous aluminosilicates with enhanced acidity and catalytic activity. The stability observed (>150 h in boiling water; 4 h at 1000 degrees C) is, for mesoporous silicates, remarkable. Unusually the hydrothermal treatment is beneficial with respect to the use of the stable aluminosilicates as solid acid catalysts.

  11. Grafting increases lycopene in seedless watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although watermelon grafting has been done for years in Asia and Europe, this production method is still novel to the U.S. Fruit from four rootstocks with scions of the seedless watermelons Palomar, TriX313, Matrix, and Petite Perfection were compared for soluble solids content, pH, and carotenoids...

  12. Endothelialized ePTFE Graft by Nanobiotechnology

    ClinicalTrials.gov

    2013-11-29

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

  13. Ferritin concentrations correlate to outcome of hematopoietic stem cell transplantation but do not serve as biomarker of graft-versus-host disease.

    PubMed

    Großekatthöfer, M; Güclü, E D; Lawitschka, A; Matthes-Martin, S; Mann, G; Minkov, M; Peters, C; Seidel, M G

    2013-08-01

    Clinical presentation and laboratory data are often too unspecific to distinguish the onset or activity of graft-versus-host disease (GvHD) from infections or toxicity. Antigen-presenting cells such as monocytes/macrophages and dendritic cells are involved in GvHD pathogenesis after allogeneic hematopoietic stem cell transplantation (HSCT). To test whether ferritin, an iron storage marker and macrophage activation-linked acute-phase protein, represents a candidate biomarker for acute or chronic GvHD in pediatric HSCT, we retrospectively evaluated a 2-year follow-up data from 131 eligible consecutive patients with different malignant and nonmalignant diseases who underwent allogeneic HSCT. Thirteen patients (10 %) suffered from acute GvHD II-IV°, 18 (14 %) had limited, and 14 (11 %) had extensive chronic GvHD. In extension of previous studies in adults investigating pre-transplant ferritin, our data show that post-HSCT hyperferritinemia (analyzed on days 0, +30, +60, +100, +180, +360, and +720) was significantly associated with decreased long-term survival (p < 0.001-0.03) in children and adolescents. Increased ferritin concentrations were associated with number and timing of red blood cell transfusions and toxic or infectious multi-organ failure but did not show significant differences between patients without GvHD and with acute grades II-IV, limited, or extensive chronic GvHD. Thus, our data do not identify ferritin as specifically GvHD-linked biomarker; however, they support the prognostic value of ferritin levels for outcome after HSCT in children.

  14. Photodynamic damage to cartilage and synovial tissue grafted on a chick's chorioallantoic membrane

    NASA Astrophysics Data System (ADS)

    Fisher, M.; Nahir, A. M.; Kimel, Sol

    1997-09-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease of the synovial joints causing pain deformities and disability. The highly vascular inflamed synovium has aggressive and destructive characteristics, it invades, erodes and gradually destroys cartilage and underlying bone. Photodynamic therapy (PDT) was performed using the chick chorioallantoic membrane (CAM) model to investigate the vitality of synovium and cartilage implanted on the CAM. Synovium, obtained from human patients, was grafted onto the CAM; gross microscopy and histology proved its vitality 7 days post grafting. Cartilage obtained from rabbit knee joint was also maintained on the CAM for 7 days. Its vitality was demonstrated by histology and by measuring metabolic and enzymatic activity of cartilage cells (chondrocytes) as well as the collagen and proteoglycans content. Selective PDT was performed using aluminum phthalocyanine tetrasulfonate (AlPcS4), a hydrophilic compound, soluble in biological solutions, as a photosensitizer. After irradiation with a diode laser (lambda equals 670 nm, 10 mW) damage was observed in vascularized synovium grafts, whereas avascular cartilage remained intact.

  15. Biodegradable metal adsorbent synthesized by graft polymerization onto nonwoven cotton fabric

    NASA Astrophysics Data System (ADS)

    Sekine, Ayako; Seko, Noriaki; Tamada, Masao; Suzuki, Yoshio

    2010-01-01

    A fibrous adsorbent for Hg ions was synthesized by radiation-induced emulsion graft polymerization of glycidyl methacrylate (GMA) onto a nonwoven cotton fabric and subsequent chemical modification. The optimal pre-irradiation dose for initiation of the graft polymerization of GMA, which minimized the effects of radiation damage on the mechanical strength of the nonwoven cotton fabric, was found to be 10 kGy. The GMA-grafted nonwoven cotton fabric was subsequently modified with ethylenediamine (EDA) or diethylenetriamine (DETA) to obtain a Hg adsorbent. The resulting amine-type adsorbents were evaluated for batch and continuous adsorption of Hg. In batch adsorption, the distribution coefficients of Hg reached 1.9×10 5 and 1.0×10 5 for EDA- and DETA-type adsorbents, respectively. A column packed with EDA-type adsorbent removed Hg from 1.8 ppm Hg solution at a space velocity of 100 h -1, which corresponds to 16,000 times the volume of the packed adsorbent. The adsorbed Hg on the EDA-type adsorbent could be completely eluted by 1 M HCl solution. A microbial oxidative degradation test revealed that the EDA-type adsorbent is biodegradable.

  16. Radiation-induced graft copolymerization of dimethylaminoethyl methacrylate onto graphene oxide for Cr(VI) removal

    NASA Astrophysics Data System (ADS)

    Ma, Hui-Ling; Zhang, Youwei; Zhang, Long; Wang, Liancai; Sun, Chao; Liu, Pinggui; He, Lihua; Zeng, Xinmiao; Zhai, Maolin

    2016-07-01

    Dimethylaminoethyl methacrylate (DMAEMA)-grafted graphene oxide hybrid materials (GO-g-P) were fabricated using γ-ray irradiation at ambient temperature. The morphology and structure of GO-g-P were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron (XPS), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). It was confirmed that DMAEMA was grafted successfully on the surface of graphene sheet. The grafting yield of GO-g-P increased with monomer concentration (0-2.5 mol L-1) and dose (0-40 kGy). The resulting adsorbent (GO-g-P) with amine groups was highly efficient for removing Cr(VI) from its acidic aqueous solution and could be easily separated by filtration. The optimum pH for Cr(VI) removal was observed at pH 1.1 and the Cr(VI) uptake of GO-g-P at this pH was 82.4 mg g-1.

  17. Cytocompatibility of Ar + plasma treated and Au nanoparticle-grafted PE

    NASA Astrophysics Data System (ADS)

    Švorčík, V.; Kasálková, N.; Slepička, P.; Záruba, K.; Král, V.; Bačáková, L.; Pařízek, M.; Lisá, V.; Ruml, T.; Gbelcová, H.; Rimpelová, S.; Macková, A.

    2009-06-01

    Polyethylene (PE) was irradiated with inert Ar plasma, and the chemically active PE surface was grafted with Au nanoparticles. The composition and the structure of the modified PE surface were studied using X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectroscopy (RBS). Changes in the surface wettability were determined from the contact angle measured in a reflection goniometer. The changes in the surface roughness and morphology were followed by atomic force microscopy (AFM). The modified PE samples were seeded with rat vascular smooth muscle cells (VSMC) or mouse NIH 3T3 fibroblasts, and their adhesion and proliferation were studied. We found that plasma discharge and Au grafting lead to dramatic changes in the surface morphology and roughness of PE. The Au nanoparticles were found not only on the sample surface, but also in the sample interior up to the depth of about 100 nm. In addition, plasma modification of the PE surface, followed with grafting Au-nanoparticles, significantly increased the attractiveness of the PE surface for the adhesion and growth of VSMC, and particularly for mouse embryonic 3T3 fibroblasts.

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

    PubMed

    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.

  19. Rib Bone Graft Adjusted to Fit the Facial Asymmetry: A Frame Structure Graft.

    PubMed

    Lee, Yoon Ho; Choi, Jong Hwan; Hwang, Kun; Choi, Jun Ho

    2015-10-01

    The authors introduce the concept of a "frame structure graft" in which a harvested rib bone was adjusted to fit facial asymmetry. On the costochondral junction of the sixth or seventh rib, a 5 cm incision was made. Through a subperiosteal dissection, the rib bone was harvested. Using a reciprocating saw, the harvested rib was scored on its anterior surface as well as its posterior surface with a partial depth at different intervals. The harvested rib bone was placed on the skin surface of the unaffected side of the face and a curvature was created exactly matching that of the unaffected side by bending the bone using a greenstick fracture. Thereafter, the graft was adjusted to conceal the asymmetry of the deficient side. The adjusted "frame structure" was transferred to the defect through the incisions on the affected side, and the "frame structure" graft was placed on the mandible or zygoma. The graft fixation was done externally with at least 2 Kirschner wires (K-wires). From January 2005 to August 2013, a total of 30 patients (13 men, 17 women, mean age 25.6 years) received a frame structure graft. All 30 patients achieved good healing at the operation site without complications. Donor-site morbidity as pneumothorax from the rib bone harvest was not found. Merits of this frame structure graft, the authors think, are that this method could allow a similar curvature to the normal side. In addition, the procedure itself is easy. PMID:26468802

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

    NASA Astrophysics Data System (ADS)

    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

  1. Nasal reconstruction with articulated irradiated rib cartilage

    SciTech Connect

    Murakami, C.S.; Cook, T.A.; Guida, R.A. )

    1991-03-01

    Nasal structural reconstruction is a formidable task in cases where there is loss of support to both the nasal dorsum and tip. A multitude of surgical approaches and materials have been used for the correction of the saddle-nose deformity with varying degrees of success. Articulated irradiated rib cartilage inserted through an external rhinoplasty approach was used to reconstruct nasal deformities in 18 patients over a 6-year period. Simultaneous use of a midline forehead flap to reconstruct the overlying soft tissue was required in four cases. Follow-up ranged from 1 to 6 years (mean, 2.8 years). Results were rewarding in most cases with marked improvement in nasal support and airway. Revision and/or replacement secondary to trauma or warping of the graft was required in four cases. None of the patients exhibited infection, extrusion, or noticeable resorption. A description of the surgical technique, review of all the cases, and recommendation for continued use of this graft material are discussed.

  2. Overgrowth of a costochondral graft in nasal reconstruction.

    PubMed

    Baek, Rong-Min; Lee, Yoonho; Song, Yong-Tai

    2005-07-01

    Nasal reconstruction with autogenous costochondral graft has been one of the surgical managements in craniofacial clefts. We have recently seen one patient who underwent this operation and the graft had overgrown like as in Pinocchio's nose-overly projecting nasal tip for almost 7 years. This case supports the notion that the costochondral graft itself carries intrinsic factors and the growth of the graft depends mainly on the costochondral graft itself. Therefore we acknowledge "the primary growth center theory" rather than "the functional matrix theory".

  3. Modification of cotton-cellulose by preirradiation grafting

    NASA Astrophysics Data System (ADS)

    Takács, E.; Wojnárovits, L.; Borsa, J.; Papp, J.; Hargittai, P.; Korecz, L.

    2005-07-01

    Acrylamide (AAm), acylic acid (Aac), 2-hydroxypropil acrylate (HPA), 2-hydroxypropil methacrylate (HPMA) and N,N‧-methylene bisacrylamide (BAAm) were grafted to cotton-cellulose by the preirradiation method. The samples were characterized by ESR, degree of polymerization (DP) and tensile strength measurements, by FTIR, gravimetry, X-ray diffraction and iodine sorption. The grafting yield was strongly monomer dependent: the highest yield was found for HPMA, for HPA a medium yield, whereas for the others relatively low values were measured. Grafting improved the swelling of the samples. The highest increase in swelling was observed on samples grafted with Aac and BAAm showing saturation at about 270% at natural pH. For AAm, HPA and HPMA at low grafting yield an increase in swelling was found and then the swelling decreased with increasing grafting yield. No direct connection was found between the grafting yield and the swelling properties.

  4. Light-Driven Reversible Alignment Switching of Liquid Crystals Enabled by Azo Thiol Grafted Gold Nanoparticles.

    PubMed

    Xue, Chenming; Xiang, Jie; Nemati, Hossein; Bisoyi, Hari Krishna; Gutierrez-Cuevas, Karla; Wang, Ling; Gao, Min; Zhou, Shuang; Yang, Deng-ke; Lavrentovich, Oleg D; Urbas, Augustine; Li, Quan

    2015-06-22

    Stimuli-directed alignment control of liquid crystals (LCs) with desired molecular orientation is currently in the limelight for the development of smart functional materials and devices. Here, photoresponsive azo thiol (AzoSH) was grafted onto gold nanoparticles (GNPs). The resulting hybrid GNPs were able to homogeneously mix with a commercially available nematic LC host, as evidenced by Cryo-TEM. Interestingly, the LC nanocomposites were found to undergo reversible alignment transition upon light irradiation as a consequence of the trans-cis photoisomerization of the azo groups on the GNP surface. LC molecules in either planar or bare glass cells were able to change their alignment to vertical upon UV irradiation, while the vertically aligned LC molecules returned to the planar or random orientation under visible irradiation. Neither the azo thiol molecules nor the unfunctionalized GNPs alone promoted the alignment of the LC molecules in the system upon light irradiation. The photoinduced vertical alignment without applied electric or magnetic field was very stable over time and with respect to temperature. Furthermore, an optically switchable device based on the photostimulated reversible alignment control of LCs was demonstrated. PMID:26097118

  5. The omentum: its use as a free vascularized graft for reconstruction of the head and neck.

    PubMed Central

    Jurkiewicz, M J; Nahai, F

    1982-01-01

    The experience at Emory University Affiliated Hospitals with transplantation of the greater omentum as a free revascularized graft in 18 patients is presented. In each instance, there was realization of the therapeutic objective, either 1) the amelioration of congenital or acquired somatic deformity (14 patients) or 2) the control of infection (4 patients). Because the omentum is a syncytium of blood vessels and a variable amount of fat within redundant leaves of peritoneal membrane laden with macrophages, it is a tissue that serves admirably its extended role as an extracelomic free transplant. The greater omentum has been used for this purpose in five patients with hemifacial atrophy (Romberg's disease); three patients with hemifacial microsomia (first and second branchial arch syndrome); two patients with extensive losses of the maxilla, palate, and face due to a shotgun blast; two patients with atrophy and facial growth arrest due to x-irradiation; and two patients with deformity of the jaw and neck following tumor resection. In three additional patients, the omentum was used to obliterate the dead space after debridement of an infected open frontal sinus following failure of conventional therapy. In one instance, a revascularized free graft of omentum was used to salvage a patient with an exposed irradiated carotid artery graft and skin flap failure following radical neck dissection. In these 18 patients, there were no intra-abdominal complications consequent to harvest of the omentum. In one patient afflicted with hemifacial atrophy, there was spotty necrosis of the overlying attenuated facial skin flap and limited fat necrosis. In the follow-up period of four months to seven years, there has been no instance of late resorption. The method is reliable and has considerable promise in reconstructive surgery. Images Fig. 1a. Fig. 1b. Fig. 2. Fig. 3. PMID:7082067

  6. Carboxylated nanodiamonds inhibit γ-irradiation damage of human red blood cells

    NASA Astrophysics Data System (ADS)

    Santacruz-Gomez, K.; Silva-Campa, E.; Melendrez-Amavizca, R.; Teran Arce, F.; Mata-Haro, V.; Landon, P. B.; Zhang, C.; Pedroza-Montero, M.; Lal, R.

    2016-03-01

    Nanodiamonds when carboxylated (cNDs) act as reducing agents and hence could limit oxidative damage in biological systems. Gamma (γ)-irradiation of whole blood or its components is required in immunocompetent patients to prevent transfusion-associated graft versus host disease (TA-GVHD). However, γ-irradiation of blood also deoxygenates red blood cells (RBCs) and induces oxidative damage, including abnormalities in cellular membranes and hemolysis. Using atomic force microscopy (AFM) and Raman spectroscopy, we examined the effect of cNDs on γ-irradiation mediated deoxygenation and morphological damage of RBCs. γ-Radiation induced several morphological phenotypes, including stomatocytes, codocytes and echinocytes. While stomatocytes and codocytes are reversibly damaged RBCs, echinocytes are irreversibly damaged. AFM images show significantly fewer echinocytes among cND-treated γ-irradiated RBCs. The Raman spectra of γ-irradiated RBCs had more oxygenated hemoglobin patterns when cND-treated, resembling those of normal, non-irradiated RBCs, compared to the non-cND-treated RBCs. cND inhibited hemoglobin deoxygenation and morphological damage, possibly by neutralizing the free radicals generated during γ-irradiation. Thus cNDs have the therapeutic potential to preserve the quality of stored blood following γ-irradiation.Nanodiamonds when carboxylated (cNDs) act as reducing agents and hence could limit oxidative damage in biological systems. Gamma (γ)-irradiation of whole blood or its components is required in immunocompetent patients to prevent transfusion-associated graft versus host disease (TA-GVHD). However, γ-irradiation of blood also deoxygenates red blood cells (RBCs) and induces oxidative damage, including abnormalities in cellular membranes and hemolysis. Using atomic force microscopy (AFM) and Raman spectroscopy, we examined the effect of cNDs on γ-irradiation mediated deoxygenation and morphological damage of RBCs. γ-Radiation induced several

  7. Bone graft and mesenchimal stem cells: clinical observations and histological analysis

    PubMed Central

    Bertolai, Roberto; Catelani, Carlo; Aversa, Alessandro; Rossi, Alessandro; Giannini, Domenico; Bani, Daniele

    2015-01-01

    Summary Autologous bone, for its osteoconductive, osteoinductive and osteogenetic properties, has been considered to be the gold standard for maxillary sinus augmentation procedures. Autograft procedures bring also some disadvantages: sometimes the limited amount of available intraoral bone makes necessary to obtain bone from an extraoral site, and this carries an associated morbidity. To overcome this problem we started using homologous freeze-dried bone in maxillary sinus augmentation procedures. This bone is industrially processed with γ-irradiation to eliminate its disease transmission potential and it’s considered safe, but this treatment also eliminates the osteoinductive and osteogenetic properties, making it just an inert scaffold for regeneration. Mesenchymal stem cells are successfully used in and orthopedic surgery for their amplification potential of healing mechanisms. We assumed that mesenchymal stem cells can restore the osteogenetic and osteoinductive properties in homologous bone grafts. The aim of this study was an histological evaluation of bone regeneration in maxillary sinus elevation using: 1) mesenchymal stem cells engineered freeze-dried bone allografts; 2) freeze-dried bone allografts. Twenty patients (10M, 10F) with a mean age of 55.2 years affected by severe maxillary atrophy were treated with bilateral maxillary sinus floor elevation. For each patient were randomly assigned a “test” side and a “control” side, different from each other exclusively in the composition of the graft material. The “control” sides were composed by corticocancellous freeze-dried bone chips and the “test” sides were composed by corticocancellous freeze-dried bone chips engineered in a bone marrow mesenchymal stem cells concentrate. After three months bone biopsies were performed on the grafts and histological specimens were made in order to evaluate the healed bone from an histological point of view. Histologically all the specimens showed

  8. Trends in bone graft use in the United States.

    PubMed

    Kinaci, Ahmet; Neuhaus, Valentin; Ring, David C

    2014-09-01

    Bone graft and bone graft substitutes are used to provide structural support and enhance bone healing. Autogenous, allogeneic, and artificial bone grafts each have advantages and drawbacks. The development of allografts, synthetic bone grafts, and new operative techniques may have influenced the use of bone grafts in recent years. The goal of this study was to analyze the use of bone grafts and bone graft substitutes in the United States during a 16-year period. Using data from the National Hospital Discharge Survey, the authors analyzed the use of autogenous and artificial bone grafts in almost 2 million patients in the United States between 1992 and 2007 using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes in 4 periods (1992-1995, 1996-1999, 2000-2003, and 2004-2007). Among an estimated almost 2 million bone graft procedures (83% autogenous, 17% artificial), the use of both types of grafts decreased. The main diagnoses for which bone grafts were used did not change; however, cervical spine diseases and lower-limb fractures decreased more remarkably. Although sex (52% male in the early 1990s to 47% in 2000-2003) and discharge status (more discharges to a short-term or long-term-care facility) significantly changed, age increased from 47 to 53 years and inpatient days decreased significantly from 6 to 5 days during the study period. The use of bone grafts and bone graft substitutes is decreasing in the United States, with a slight shift from autogenous to substitute grafts. PMID:25350620

  9. Outcomes of thrombosed arteriovenous grafts: comparison of stents vs angioplasty.

    PubMed

    Maya, I D; Allon, M

    2006-03-01

    The usual radiologic approach to thrombosed grafts is a combination of thrombectomy and angioplasty of the underlying lesion. However, the primary (unassisted) graft patency after thrombectomy is quite poor. We evaluated whether graft patency following thrombectomy is improved by placement of a stent in the stenotic lesion. Using a prospective, computerized vascular access database, we identified 14 patients with thrombosed arteriovenous (A-V) grafts treated with a stent at the venous anastomosis (stent group). The outcomes of these grafts was compared to those observed in 34 sex, age-, and date-matched control patients whose thrombosed A-V grafts were angioplastied (control group). Both groups were comparable in age, sex, race, diabetic status, graft age, and number of previous graft interventions. The immediate technical success, as indicated by the post-procedure graft to systemic pressure ratio, was similar in the stent and control groups (0.33+/-0.16 vs 0.41+/-0.17, P=0.14). The primary graft patency (time from thrombectomy to next intervention) was significantly longer for the stent group (median survival, 85 vs 27 days, P=0.02). Assisted or secondary patency (time from thrombectomy to permanent graft failure) was also longer for the stent group (median survival, 1215 vs 46 days, P=0.049). In conclusion, treatment of thrombosed grafts with a stenosis at the venous anastomosis with a stent results in longer primary and secondary graft survival, as compared to treatment with angioplasty. Stent placement may be a useful treatment modality in a subset of patients with thrombosed A-V grafts and stenosis at the venous anastomosis.

  10. Influence of relaxation transitions on radiation-initiated cationic graft polymerization. [Gamma radiation

    SciTech Connect

    Kudryavtsev, V.N.; Kabanov, V.Ya.; Chalykh, A.E.; Spitsyn, V.I.

    1982-05-01

    Radiation grafting of vinyl n-butyl ether (VBE) to polyvinyl chloride (PVC) over a broad temperature range was investigated. The relaxation transitions in the PVC/VBE system were also determined. Grafting of vinyl alkyl ethers proceeds entirely by a cationic mechanism in a reaction medium that has been dried to a water concentration no greater than 0.1-1.0 ppm. In this connection, the diffusion properties of water in the temperature region were studied. Commercial films of unplasticized PVC (thickness 200 M); were subjected to swelling in two systems: in a 50% solution of VBE in benzene at 25/sup 0/C, and in the pure monomer at 40/sup 0/C. The reaction mixtures were first dried over metallic sodium in a deaerated atmosphere. The specimens were irradiated in a Co gamma-radiation unit to a dose of 10 kGy at a dose rate of 3 Gy/sec. The first reaction mixture was investigated over a range of temperatures from -60/sup 0/ to +70/sup 0/C, and the second from -15/sup 0/ to +50/sup 0/C. The degree of grafting was determined from the increase in weight of the original ungrafted film. The temperature was held to within +/-1/sup 0/C. The relaxation transitions in the swollen polymer systems were determined by two methods, thermostimulated current (TSC) and thermomechanics (TM). It was found that in the region of the glass transition of a swollen PVC-VBE system, radiation-initiated cationic graft polymerization proceeds at a maximal rate, and there are changes in state of the water molecules (the agents of breaking the ion reaction chain) and in their diffusion properties within the matrix.

  11. Use of a free bladder mucosal graft for simple repair of vesicovaginal fistulae.

    PubMed

    Ostad, M; Uzzo, R G; Coleman, J; Young, G P

    1998-07-01

    The aim of this paper is to describe a simple, fast, and effective method for repair of difficult vesicovaginal fistulae by means of a free bladder mucosal graft. Six patients with high, large, multiple, or recurrent vesicovaginal fistulae were treated using a free bladder mucosal graft. Three patients underwent "early" repair (less than 3 months from time of injury) and 3 "late" repair (more than 6 months from time of injury). Via a suprapubic cystotomy, the mucosa of the fistulous tract was debrided without any attempt to excise the tract or close the bladder or vaginal defects. A free bladder mucosal graft was harvested from an unaffected portion of the bladder and placed over the fistulous tract, and mucosal approximation was made using interrupted 5-0 chromic stay sutures. The donor urothelial defect was allowed to re-epithelialize. A Foley catheter, suprapubic tube, and vaginal packing were left in place. Five patients noted an immediate result, with no evidence of leakage, and the suprapubic tube was removed by week 3. One patient required prolonged catheter drainage, and the tube was successfully removed by week 6. This patient had undergone irradiation. All patients remain dry at follow-up, which ranges from 2 to 6 years. We describe a simple and effective method for transabdominal vesicovaginal fistula repair, involving minimal mobilization, decreased dissection, and no need for rotational or interposition flaps, obviating the need to open the peritoneum. A free bladder mucosal graft can be used regardless of the individual anatomy or proximity to the ureteral orifices, because it can easily be tailored. This technique represents an important repair of difficult, recurrent, or multiple vesicovaginal fistulae. PMID:9671883

  12. Oil palm empty fruit bunch (OPEFB) fiber reinforced PVC/ENR blend-electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Ratnam, Chantara Thevy; Raju, Gunasunderi; Yunus, Wan Md Zin Wan

    2007-12-01

    The effect of irradiation on the tensile properties of oil palm empty fruit bunch (OPEFB) fiber reinforced poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blend using HAAKE Rheomixer at 150 °C. The composites were then irradiated by using a 3.0 MeV electron beam machine at doses ranging from 0 to 100 kGy in air and room temperature. The tensile strength, Young's modulus, elongation at break and gel fraction of the composites were measured. Comparative studies were also made by using poly(methyl acrylate) grafted OPEFB fiber in the similar blend system. An increase in tensile strength, Young's modulus and gel fraction, with a concurrent reduction in the elongation at break (Eb) of the PVC/ENR/OPEFB composites were observed upon electron beam irradiation. Studies revealed that grafting of the OPEFB fiber with methyl acrylate did not cause appreciable effect to the tensile properties and gel fraction of the composites upon irradiation. The morphology of fractured surfaces of the composites, examined by a scanning electron microscope showed an improvement in the adhesion between the fiber and the matrix was achieved upon grafting of the fiber with methyl acrylate.

  13. Skin graft rejection in mice repopulated with marrow of the skin donor type: a Skn gene in a congenic line

    SciTech Connect

    Harrison, D.E.; Mobraaten, L.E.

    1984-01-01

    Genetically anemic W/Wv mice and lethally irradiated wild-type mice were cured and populated by grafted marrow cells from donor mice of three congenic lines that differed at non-H-2 histocompatibility loci. Tail skin from mice of the same congenic lines was grafted 3-4 weeks later. In two cases, the recipients behaved as expected, no longer rejecting skin syngeneic with the marrow graft that had repopulated them. However, B6-H-24c skin was rejected by WBB6F1-W/Wv mice that were cured with B6-H-24c marrow showing a mean survival time of 9.9 weeks. It was rejected somewhat faster, with a mean survival time of 5.9 weeks, by W/Wv mice cured with marrow from other types of donors. Results were more variable in lethally irradiated WBB6F1-+/+ recipients of B6-H-24c marrow, but they also rejected B6-H-24c skin. Both types of recipients remained chimeras after the skin was rejected, showing more than 90% of the B6-H-24c hemoglobin type. This is the first report of a Skn gene in a congenic line.

  14. Homogeneous graft copolymerization of styrene onto cellulose in a sulfur dioxide-diethylamine-dimethyl sulfoxide cellulose solvent

    SciTech Connect

    Tsuzuki, M.; Hagiwara, I.; Shiraishi, N.; Yokota, T.

    1980-12-01

    Graft copolymerization of styrene onto cellulose was studied in a homogeneous system (SO/sub 2/(liquid)- diethylamine (DEA)-dimethyl sulfoxide (DMSO) medium)) by ..gamma..-ray mutual irradiation technique. At the same time, homopolymerization of styrene was also examined separately in DMSO, SO/sub 2/-DMSO, DEA-DMSO, and SO/sub 2/-DEA-DMSO media by the same technique. Polymerization of styrene hardly occurs on concentrations above 10 mole SO/sub 2/-DEA complex per mole glucose unit. Maximum percent grafting was obtained in concentrations of 4 mole, after which it decreased rapidly. Total conversion and percent grafting increased with the irradiation time. The value (=0.55) of the slope of the total conversion rate plotted against the dose was only a little higher than the 1/2 which was expected from normal kinetics. No retardation in homopolymerization of styrene in DMSO, SO/sub 2/-DMSO, and DEA-DMSO was evident, while the retardation of homopolymerization in the SO/sub 2/-DEA-DMSO medium was measurable. Sulfur atoms were detected in the polymers obtained in both of SO/sub 2/-DMSO and SO/sub 2/-DEA-DMSO solutions. All of the molecular weights of polymers obtained in the present experiment were very low (3.9 x 10/sup 3/-1.75 x 10/sup 4/).

  15. Water swelling properties of the electron beam irradiated PVA-g-AAc hydrogels

    NASA Astrophysics Data System (ADS)

    Wang, Qingguo; Zhou, Xue; Zeng, Jinxia; Wang, Jizeng

    2016-02-01

    In this paper, the electron beam irradiation technology being more suitable for the industry application is explored to fabricate the acrylic acid (AAc) monomer-grafted polyvinyl alcohol (PVA-g-AAc) hydrogels. ATR-IR spectra of the PVA-g-AAc hydrogels shows an obvious absorption peak of the sbnd Cdbnd O group at 1701 cm-1, indicating that the AAc monomers were grafted onto the PVA macromolecules. This paper also studied some effects of the mass ratio of PVA/AAc, pH of buffer solution and irradiation dosage on the water swelling properties of the electron beam irradiated PVA-g-AAc hydrogels. The water swelling ratio of PVA-g-AAc hydrogels decreases with increased irradiation dosage and mass ratio of PVA/AAc, whereas swelling ratio increases with increased pH of buffer solution and soaking time. The water-swelling behavior of PVA-g-AAc hydrogels occurred easily in an alkaline environment, particularly in a buffer solution with pH 9.2. Both PVA-g-AAc hydrogels (PVA/AAc = 1/5, w/w) irradiated with 5 kilogray (kGy) and PVA-g-AAc hydrogels (PVA/AAc = 1/1, w/w) irradiated with 15 kGy could easily absorb water and lead to high water swelling ratios (up to about 600%), which are potential candidates to meet the requirements for some biomedical applications.

  16. Graft rejection by cytolytic T cells. Specificity of the effector mechanism in the rejection of allogeneic marrow

    SciTech Connect

    Nakamura, H.; Gress, R.E. )

    1990-02-01

    Cellular effector mechanisms of allograft rejection remain incompletely described. Characterizing the rejection of foreign-marrow allografts rather than solid-organ grafts has the advantage that the cellular composition of the marrow graft, as a single cell suspension, can be altered to include cellular components with differing antigen expression. Rejection of marrow grafts is sensitive to lethal doses of radiation in the mouse but resistant to sublethal levels of radiation. In an effort to identify cells mediating host resistance, lymphocytes were isolated and cloned from spleens of mice 7 days after sublethal TBI (650 cGy) and inoculation with allogeneic marrow. All clones isolated were cytolytic with specificity for MHC encoded gene products of the allogeneic marrow donor. When cloned cells were transferred in vivo into lethally irradiated (1025 cGy) recipients unable to reject allogeneic marrow, results utilizing splenic 125IUdR uptake indicated that these MHC-specific cytotoxic clones could suppress marrow proliferation. In order to characterize the effector mechanism and the ability of the clones to affect final engraftment, double donor chimeras were constructed so that 2 target cell populations differing at the MHC from each other and from the host were present in the same marrow allograft. Results directly demonstrated an ability of CTL of host MHC type to mediate graft rejection and characterized the effector mechanism as one with specificity for MHC gene products.

  17. UV-induced graft polymerization of acrylic acid in the sub-micronchannels of oxidized PET track-etched membrane

    NASA Astrophysics Data System (ADS)

    Korolkov, Ilya V.; Mashentseva, Anastassiya A.; Güven, Olgun; Taltenov, Abzal A.

    2015-12-01

    In this article, we report on functionalization of track-etched membrane based on poly(ethylene terephthalate) (PET TeMs) oxidized by advanced oxidation systems and by grafting of acrylic acid using photochemical initiation technique for the purpose of increasing functionality thus expanding its practical application. Among advanced oxidation processes (H2O2/UV) system had been chosen to introduce maximum concentration of carboxylic acid groups. Benzophenone (BP) photo-initiator was first immobilized on the surfaces of cylindrical pores which were later filled with aq. acrylic acid solution. UV-irradiation from both sides of PET TeMs has led to the formation of grafted poly(acrylic acid) (PAA) chains inside the membrane sub-micronchannels. Effect of oxygen-rich surface of PET TeMs on BP adsorption and subsequent process of photo-induced graft polymerization of acrylic acid (AA) were studied by ESR. The surface of oxidized and AA grafted PET TeMs was characterized by UV-vis, ATR-FTIR, XPS spectroscopies and by SEM.

  18. Radiation induced emulsion graft polymerization of 4-vinylpyridine onto PE/PP nonwoven fabric for As(V) adsorption

    NASA Astrophysics Data System (ADS)

    Akkaş Kavaklı, Pınar; Kavaklı, Cengiz; Seko, Noriaki; Tamada, Masao; Güven, Olgun

    2016-10-01

    A novel nonwoven fabric adsorbent having 4-vinylpyridine functional groups was prepared by using radiation-induced emulsion graft polymerization method and grafting 4-vinylpyridine monomer onto a polyethylene-coated polypropylene nonwoven fabric (NWF) in aqueous emulsion solution. The grafting conditions of the 4-vinylpyridine monomer onto the NWF were optimised and 150% Dg VP-g-NWF was prepared using 30 kGy pre-irradiation dose, 5% VP monomer concentration and 0.5% (w/w) Tween 20 in aqueous emulsion. Grafted 4-vinylpyridine chains on the NWF were then quaternized for the preparation of QVP-g-NWF adsorbent. All fabric structures were characterized by using Fourier-transform infrared spectrometer, x-ray photoelectron spectrometer and scanning electron microscope. QVP-g-NWF adsorbent was used in batch adsorption experiments for As(V) ions by studying the pH, contact time, and initial As(V) ion concentration parameters. Results showed that QVP-g-NWF adsorbent has significant As(V) adsorption and experimental As(V) adsorption capacity was 98.04 mg As(V)/g polymer from 500 mg/L initial As(V) concentration at pH 7.00.

  19. Effects of storage on irradiated red blood cells: An in-vitro and in-vivo study. Master's thesis

    SciTech Connect

    Knoll, S.E.

    1991-08-01

    Irradiation of red blood cell units has recently become a topic of special concern as the result of increasing reports of graft versus host disease in immunocompetent blood transfusion recipients. This study was designed to evaluate the potassium elevations observed in stored irradiated red blood cells and to evaluate the in vivo survival of stored irradiated red blood cells using a dog model. In the in vitro study ten units of human CPDA-1 packed red blood cells were made into paired aliquots; one aliquot of each pair was irradiated with 3000 rads of gamma radiation and the potassium content measured at points throughout 35 days of storage. A significant increase in potassium levels in the irradiated aliquots was observed from the first day after irradiation and continued through the entire storage period.

  20. Induction of transplantation tolerance in mice across major histocompatibility barrier by using allogeneic thymus transplantation and total lymphoid irradiation

    SciTech Connect

    Waer, M.; Palathumpat, V.; Sobis, H.; Vandeputte, M. )

    1990-07-15

    The use of allogeneic thymus transplantation as a means of inducing tolerance across MHC barriers was investigated in thymectomized, total lymphoid irradiated BALB/c mice. In 90% of the animals long term outgrowth of histologically normal C57BL thymus grafts was observed. None of the latter animals was chimeric. All thymus graft-bearing mice showed specific nonresponsiveness for C57BL MHC Ag in mixed lymphocyte reaction and cell-mediated lympholysis. Spleen cells of the C57BL thymus-bearing mice were unable to induce lethal graft-vs-host disease in neonatal (BALB/c X C57BL) F1 mice but provoked a vigorous graft-vs-host disease reaction in (BALB/c x C3H) F1 neonates. Tolerant mice permanently accepted C57BL heart and pancreas grafts, but all rejected C3H grafts. Induction of tolerance of BALB/c pre-T cells through allogeneic thymus graft and/or specific suppressor cells seems to be involved. The present model offers new opportunities to study thymocyte maturation in a fully allogeneic environment and may yield applications for clinical organ transplantation.

  1. Motexafin lutetium in graft coronary artery disease

    NASA Astrophysics Data System (ADS)

    Woodburn, Kathryn W.; Rodriquez, Shari L.; Yamaguchi, Atsushi; Hayase, Motoya; Robbins, Robert C.; Kessel, David

    2000-03-01

    Graft coronary artery disease (GCAD) is the chief complication following cardiac transplantation. Presently, there are limited treatment options. Insights into more expedient diagnosis and amelioration, if only partially, of GCAD are fervently sought. The selectivity of Antrin Injection (Lu-Tex) with subsequent photoactivation has been evaluated in several preclinical atherosclerosis models. The inhibitory effect of Lu-Tex induced photosensitization was demonstrated with human bypass coronary smooth muscle cells. The biodistribution of Lu-Tex was evaluated in a rat model of heterotopic cardiac allografts 60 days following transplantation. Lu-Tex was retained in the cardiac allograft, exhibiting a five-fold increase in retention between the allograft and native heart. These findings lead us to suggest that further studies are warranted to ascertain the merits of Lu-Tex for the diagnosis and possible attenuation of chronic graft vascular disease.

  2. Tooth-derived bone graft material

    PubMed Central

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

    2013-01-01

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

  3. Comminuting irradiated ferritic steel

    DOEpatents

    Bauer, Roger E.; Straalsund, Jerry L.; Chin, Bryan A.

    1985-01-01

    Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

  4. MASSIVE LEAKAGE IRRADIATOR

    DOEpatents

    Wigner, E.P.; Szilard, L.; Christy, R.F.; Friedman, F.L.

    1961-05-30

    An irradiator designed to utilize the neutrons that leak out of a reactor around its periphery is described. It avoids wasting neutron energy and reduces interference with the core flux to a minimum. This is done by surrounding all or most of the core with removable segments of the material to be irradiated within a matrix of reflecting material.

  5. Perspective on food irradiation

    SciTech Connect

    Not Available

    1987-02-01

    Recent US Food and Drug Administration approval of irradiation treatment for fruit, vegetables and pork has stimulated considerable discussion in the popular press on the safety and efficacy of irradiation processing of food. This perspective is designed to summarize the current scientific information available on this issue.

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

    PubMed

    Yuan, Lijuan; Shen, Jianliang

    2016-09-01

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

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

    PubMed Central

    Yuan, Lijuan; Shen, Jianliang

    2016-01-01

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

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

    PubMed

    Bhandari, Vipul; Siddharthan, K S

    2015-01-01

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

  9. A Different Cartilage Graft Technique: Perichondrium-Preserved Palisade Island Graft in Tympanoplasty.

    PubMed

    Genc, Selahattin

    2016-03-01

    Various graft materials have been used since tympanoplasty technique was first described. In this study, the authors aimed to share our modified island cartilage graft technique.A total of 47 ears of 46 patients on whom tympanoplasty or tympanomastoidectomy operation was performed in our clinic because of chronic otitis media were included in the study.Mean preoperative air-bone gap of the patients was 32.25 ± 11.85 dB and mean postoperative air-bone gap was 19.25 ± 10.46 dB. The difference was statistically significant (P < 0.001). When all the patients were evaluated, preoperative and postoperative air conduction pure tone audiometry values were 43.38 ± 14.74 dB and 32.61 ± 15.62 dB, respectively. The difference was statistically significant (P < 0.001). Graft success rate in terms of perforation closure was found to be 44/47 (93.61%).Our modified island cartilage graft technique is easy to apply and its graft success rate and hearing results are good.

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

    PubMed Central

    Yuan, Lijuan; Shen, Jianliang

    2016-01-01

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

  11. Soft Tissue Augmentation with Silk Composite Graft

    PubMed Central

    Park, Yong-Tae; Kweon, Hae Yong; Kim, Seong-Gon

    2014-01-01

    Purpose: The objective of this study was to evaluate the interaction between 4-hexylresorcinol (4HR) and antibody as that affects the performance of a silk-4HR combination graft for soft tissue augmentation in an animal model. Methods: The silk graft materials consisted of four types: silk+10% tricalcium phosphate (TCP) (ST0), silk+10% TCP+1% 4HR (ST1), silk+10% TCP+3% 4HR (ST3), and silk+10% TCP+6% 4-HR (ST6). The antibody binding assay tested the 4HR effect and scanning electron microscopic (SEM) exam was done for silk grafts. The animal experiment used a subcutaneous pocket mouse model. The graft – SH0 or SH1 or SH3 or SH6 – was placed in a subcutaneous pocket. The animals were killed at one, two, and four weeks, postoperatively. The specimens were subjected to histological analysis and lysozyme assay. Results: Groups with 4HR applied showed lower antibody binding affinity to antigen compared to groups without 4HR. In the SEM examination, there was no significant difference among groups. Histological examinations revealed many foreign body giant cells in ST0 and ST1 group at four weeks postoperatively. Both ST3 and ST6 groups developed significantly lower levels of giant cell values compared to ST0 and ST1 groups (P <0.001) at four weeks postoperatively. In the lysozyme assay, the ST1 and ST3 groups showed denser signals than the other groups. Conclusion: 4HR combined silk implants resulted in high levels of vascular and connective tissue regeneration. PMID:27489833

  12. Ulnar Nerve Injury after Flexor Tendon Grafting.

    PubMed

    McCleave, Michael John

    2016-10-01

    A 43-year-old female is presented who underwent a two-stage tendon reconstruction and developed a low ulnar nerve palsy postoperatively. Exploration found that the tendon graft was passing through Guyon's canal and that the ulnar nerve was divided. This is a previously unreported complication. The reconstruction is discussed, the literature reviewed and a guide is given on how to identify the correct tissue plane when passing a tendon rod. PMID:27595967

  13. Graft selection in anterior cruciate ligament reconstruction.

    PubMed

    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

  14. Peripheral Stent Placement in Hemodialysis Grafts

    SciTech Connect

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

    2009-09-15

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

  15. Endoscopic Ankle Lateral Ligament Graft Anatomic Reconstruction.

    PubMed

    Michels, Frederick; Cordier, Guillaume; Guillo, Stéphane; Stockmans, Filip

    2016-09-01

    Chronic instability is a common complication of lateral ankle sprains. If nonoperative treatment fails, a surgical repair or reconstruction may be indicated. Today, endoscopic techniques to treat ankle instability are becoming more popular. This article describes an endoscopic technique, using a step-by-step approach, to reconstruct the ATFL and CFL with a gracilis graft. The endoscopic technique is reproducible and safe with regard to the surrounding anatomic structures. Short and midterm results confirm the benefits of this technique. PMID:27524711

  16. Graft selection in anterior cruciate ligament reconstruction.

    PubMed

    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

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

    PubMed

    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.

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

    SciTech Connect

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

    1988-10-01

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

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

    SciTech Connect

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

    1991-06-01

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

  20. Electrospun Vascular Grafts with Improved Compliance Matching to Native Vessels

    PubMed Central

    Nezarati, Roya M.; Eifert, Michelle B.; Dempsey, David K.; Cosgriff-Hernandez, Elizabeth

    2014-01-01

    Coronary artery bypass grafting (CABG) is one of the most commonly performed major surgeries in the United States. Autologous vessels such as the saphenous vein are the current gold standard for treatment; however, synthetic vascular prostheses made of expanded poly(tetrafluoroethylene) (ePTFE) or poly(ethylene terephthalate) (PET) are used when autologous vessels are unavailable. These synthetic grafts have a high failure rate in small diameter (<4 mm) applications due to rapid re-occlusion via intimal hyperplasia. Current strategies to improve clinical performance are focused on preventing intimal hyperplasia by fabricating grafts with compliance and burst pressure similar to native vessels. To this end, we have developed an electrospun vascular graft from segmented polyurethanes with tunable properties by altering material chemistry and graft microarchitecture. Relationships between polyurethane tensile properties and biomechanical properties were elucidated to select polymers with desirable properties. Graft thickness, fiber tortuosity, and fiber fusions were modulated to provide additional tools for controlling graft properties. Using a combination of these strategies, a vascular graft with compliance and burst pressure exceeding the saphenous vein autograft was fabricated (compliance = 6.0 ± 0.6 %/mmHg × 10−4, burst pressure = 2260 ± 160 mmHg). This graft is hypothesized to reduce intimal hyperplasia associated with low compliance in synthetic grafts and improve long term clinical success. Additionally, the fundamental relationships between electrospun mesh microarchitecture and mechanical properties identified in this work can be utilized in various biomedical applications. PMID:24846218

  1. Irradiation Creep in Graphite

    SciTech Connect

    Ubic, Rick; Butt, Darryl; Windes, William

    2014-03-13

    An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  3. A Patient with Recurrent Arteriovenous Graft Thrombosis.

    PubMed

    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.

  4. Block and Graft Copolymers of Polyhydroxyalkanoates

    NASA Astrophysics Data System (ADS)

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

    2004-03-01

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

  5. [Robot-assisted Coronary Artery Bypass Grafting].

    PubMed

    Ishikawa, Norihiko; Watanabe, Go

    2016-07-01

    The application for robot-assisted coronary surgery ranges from internal thoracic artery (ITA) harvesting with hand-sewn anastomoses to totally endoscopic coronary artery bypass grafting (TECAB), either on- or off-pump. The bilateral IMA can be harvested with the aid of a surgical robot and then multivessel bypass grafting can follow. Such robot-assisted minimally invasive direct coronary artery bypass grafting is called "ThoraCAB". Surgical robots cannot only endoscopically harvest the ITA but they can also anastomose the coronary artery in TECAB. But TECAB still has the difficulties, such as narrow surgical field in Japanese patients. Both procedures have the significant advantages of minimizing surgical trauma, such as reduced comlications, faster return back to normal activities and being improved cosmesis, and which have resulted in the development of minimally invasive surgery. Robot-assisted cardiac surgery for structural heart disease has been approved by the Ministry of Health, Labour and Welfare (MHLW) since December 2015, however, robot-assisted cardiac surgery for TECAB has not been approved yet in Japan. PMID:27440015

  6. PHYSICOCHEMICAL CHARACTERIZATION OF LYOPHILIZED BOVINE BONE GRAFTS

    PubMed Central

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

    2015-01-01

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

  7. Effect of immobilized collagen type IV on biological properties of endothelial cells for the enhanced endothelialization of synthetic vascular graft materials.

    PubMed

    Heo, Yunhoe; Shin, Young Min; Lee, Yu Bin; Lim, Youn Mook; Shin, Heungsoo

    2015-10-01

    Regeneration of healthy endothelium onto vascular graft materials is imperative for prevention of intimal hyperplasia and thrombogenesis. In this study, we investigated the effect of collagen type IV (COL-IV) immobilized onto electrospun nanofibers on modulation of endothelial cell (EC) function, as a potential signal to rapid endothelialization of vascular grafts. COL-IV is assembled in basement membrane underneath intimal layer and regulates morphogenesis of blood vessels. For immobilization of COL-IV, poly(l-lactic acid) (PLLA) nanofibers (PL) were prepared as a model vascular graft substrate, onto which acrylic acid (AAc) was then grafted by using gamma-ray irradiation. AAc graft was dependent on irradiation doses and AAc concentrations, which allowed us to select the condition of 5% (v/v) AAc and 10 kGy for further conjugation of COL-IV. COL-IV immobilization was proportionally controlled as a function of its concentration. Atomic force microscope (AFM) analysis qualitatively supported immobilization of COL-IV, demonstrating increase in root mean square roughness of the PL from 665.37 ± 13.20 nm to 1440.74 ± 33.24. However, the Young's modulus of nanofibers was retained as approximately 1 MPa, regardless of surface modification. The number of ECs attached on the nanofibers with immobilized COL-IV was significantly increased by 5 times (1052 ± 138 cells/mm(2)) from pristine PL (234 ± 41 cells/mm(2)). In addition, the effect of immobilized COL-IV was profound for enhancing proliferation and up-regulation of markers implicated in rapid endothelialization. Collectively, our results suggest that COL-IV immobilized onto electrospun PLLA nanofibers may serve as a promising instructive cue used in vascular graft materials.

  8. A novel photo-grafting of acrylamide onto carboxymethyl starch. 1. Utilization of CMS-g-PAAm in easy care finishing of cotton fabrics.

    PubMed

    El-Sheikh, Manal A

    2016-11-01

    The photosensitized grafting of vinyl monomers onto a range of polymeric substrates has been the subject of particular interest in the recent past. Carboxymethyl starch (CMS)-poly acrylamide (PAAm) graft copolymer (CMS-g-PAAm) with high graft yield was successfully prepared by grafting of acrylamide onto CMS using UV irradiation in the presence of the water soluble 4-(trimethyl ammoniummethyl) benzophenone chloride photoinitiator. CMS-g-PAAm with nitrogen content of 8.3% and grafting efficiency up to 98.9% was obtained using 100% AAm, a material: liquor ratio of 1:14 and 1% photinitiator at 30°C for 1h of UV irradiation. The synthesis of CMS-g-PAAm was confirmed by FTIR and Nitrogen content (%). Surface morphology of CMS and surface morphological changes of CMS after grafting with AAm were studied using SEM. Thermal properties of both CMS and CMS-g-PAAm were studied using TGA and DSC. To impart easy care finishing to cotton fabrics, aqueous formulations of: CMS-g-PAAm, dimethylol dihydroxy ethylene urea (DMDHEU), CMS-g-PAAm-DMDHEU mixture or methylolated CMS-g-PAAm were used. Cotton fabrics were padded in these formulations, squeezed to a wet pick up 100%, dried at 100°C for 5min, cured at 150°C for 5min, washed at 50°C for 10min and air-dried. CRA (crease recovery angle) of untreated fabrics and fabrics finished with a mixture of 2% CMS-g-PAAm and 10% DMDHEU or methylolated CMS-g-PAAm (10% formaldehyde) were: 136°, 190°, 288° respectively. Increasing the number of washing cycles up to five cycles results in an insignificant decrease in the CRA and a significant decrease in RF (releasable formaldehyde) of finished fabric samples. The morphologies of the finished and unfinished cotton fabrics were performed by SEM.

  9. A novel photo-grafting of acrylamide onto carboxymethyl starch. 1. Utilization of CMS-g-PAAm in easy care finishing of cotton fabrics.

    PubMed

    El-Sheikh, Manal A

    2016-11-01

    The photosensitized grafting of vinyl monomers onto a range of polymeric substrates has been the subject of particular interest in the recent past. Carboxymethyl starch (CMS)-poly acrylamide (PAAm) graft copolymer (CMS-g-PAAm) with high graft yield was successfully prepared by grafting of acrylamide onto CMS using UV irradiation in the presence of the water soluble 4-(trimethyl ammoniummethyl) benzophenone chloride photoinitiator. CMS-g-PAAm with nitrogen content of 8.3% and grafting efficiency up to 98.9% was obtained using 100% AAm, a material: liquor ratio of 1:14 and 1% photinitiator at 30°C for 1h of UV irradiation. The synthesis of CMS-g-PAAm was confirmed by FTIR and Nitrogen content (%). Surface morphology of CMS and surface morphological changes of CMS after grafting with AAm were studied using SEM. Thermal properties of both CMS and CMS-g-PAAm were studied using TGA and DSC. To impart easy care finishing to cotton fabrics, aqueous formulations of: CMS-g-PAAm, dimethylol dihydroxy ethylene urea (DMDHEU), CMS-g-PAAm-DMDHEU mixture or methylolated CMS-g-PAAm were used. Cotton fabrics were padded in these formulations, squeezed to a wet pick up 100%, dried at 100°C for 5min, cured at 150°C for 5min, washed at 50°C for 10min and air-dried. CRA (crease recovery angle) of untreated fabrics and fabrics finished with a mixture of 2% CMS-g-PAAm and 10% DMDHEU or methylolated CMS-g-PAAm (10% formaldehyde) were: 136°, 190°, 288° respectively. Increasing the number of washing cycles up to five cycles results in an insignificant decrease in the CRA and a significant decrease in RF (releasable formaldehyde) of finished fabric samples. The morphologies of the finished and unfinished cotton fabrics were performed by SEM. PMID:27516255

  10. Radiation-grafting of thermo- and pH-responsive poly(N-vinylcaprolactam-co-acrylic acid) onto silicone rubber and polypropylene films for biomedical purposes

    NASA Astrophysics Data System (ADS)

    Ferraz, Caroline C.; Varca, Gustavo H. C.; Ruiz, Juan-Carlos; Lopes, Patricia S.; Mathor, Monica B.; Lugão, Ademar B.; Bucio, Emilio

    2014-04-01

    This work focuses on the effects of gamma-ray irradiation conditions on the stimuli-responsiveness of polypropylene (PP) films and silicone (SR) rubber substrates grafted with N-vinylcaprolactam (NVCL) and acrylic acid (AAc). PP films and SR rubber were modified by simultaneous polymerization and grafting of NVCL and AAc, using pre-irradiation oxidative method at a dose rate of 12.23 kGy h-1 and doses ranging from 5 to 70 kGy. NVCL and AAc solutions (1/1, v/v) at 50% monomer concentration (v/v) in toluene were added to the sample substrates, degassed, sealed and heated at 60 and 70 °C for 12 h. After grafting, the samples were soaked in ethanol and distilled water for 24 h successively, followed by drying under vacuum. Samples were characterized by FTIR-ATR, DSC and swelling measurements. Critical points (pH critical or LCST) of grafts were obtained in a pH-environment (pH ranges from 2.2 to 9) and in a thermo-environment (temperature ranges from 22 to 50 °C). Cytotoxicity evaluation was performed using fibroblast BALB/c 3T3 cells. The relationship between NVCL-co-AAc grafting and radiation dose was different for each substrate, PP and SR. At 50% NVCL/AAc concentration in toluene, grafting values were higher for SR than for PP. Despite the fact that PP-g-(NVCL-co-AAc) membrane presented a cytotoxic profile at the highest experimental concentration assayed, cytotoxicity evaluation revealed noncytotoxic profiles for the membranes synthesized highlighting their applications for biomedical purposes.

  11. Effect of immobilized collagen type IV on biological properties of endothelial cells for the enhanced endothelialization of synthetic vascular graft materials.

    PubMed

    Heo, Yunhoe; Shin, Young Min; Lee, Yu Bin; Lim, Youn Mook; Shin, Heungsoo

    2015-10-01

    Regeneration of healthy endothelium onto vascular graft materials is imperative for prevention of intimal hyperplasia and thrombogenesis. In this study, we investigated the effect of collagen type IV (COL-IV) immobilized onto electrospun nanofibers on modulation of endothelial cell (EC) function, as a potential signal to rapid endothelialization of vascular grafts. COL-IV is assembled in basement membrane underneath intimal layer and regulates morphogenesis of blood vessels. For immobilization of COL-IV, poly(l-lactic acid) (PLLA) nanofibers (PL) were prepared as a model vascular graft substrate, onto which acrylic acid (AAc) was then grafted by using gamma-ray irradiation. AAc graft was dependent on irradiation doses and AAc concentrations, which allowed us to select the condition of 5% (v/v) AAc and 10 kGy for further conjugation of COL-IV. COL-IV immobilization was proportionally controlled as a function of its concentration. Atomic force microscope (AFM) analysis qualitatively supported immobilization of COL-IV, demonstrating increase in root mean square roughness of the PL from 665.37 ± 13.20 nm to 1440.74 ± 33.24. However, the Young's modulus of nanofibers was retained as approximately 1 MPa, regardless of surface modification. The number of ECs attached on the nanofibers with immobilized COL-IV was significantly increased by 5 times (1052 ± 138 cells/mm(2)) from pristine PL (234 ± 41 cells/mm(2)). In addition, the effect of immobilized COL-IV was profound for enhancing proliferation and up-regulation of markers implicated in rapid endothelialization. Collectively, our results suggest that COL-IV immobilized onto electrospun PLLA nanofibers may serve as a promising instructive cue used in vascular graft materials. PMID:26196092

  12. Lethal graft-versus-host disease in nude mice. I. Establishment of model systems

    SciTech Connect

    Kuribayashi, K.; Masuda, T.; Hanaoka, M.

    1988-08-01

    We examined whether nude mice, which are deficient in T cell function, could be used as a model for induction of lethal graft-versus-host disease. Nude mice injected with MHC-disparate spleen cells exhibited only transient GVH reaction such as splenomegaly. Inoculation of B6 spleen cells into BALB/c nude mice produced high titers of alloantibodies to the donor cells. These alloantibodies eliminated host-MHC-reactive donor T cells from the host. After abolition by 400 rads irradiation of the capacity of nude mice to produce antibody, lethal GVHD could be induced by allogeneic spleen cell transfer and was mediated by donor T cells. This lethal GVHD was prevented by prior administration of antidonor alloantibody to the irradiated recipients at least 24 hr before donor-cell grafting. The role of alloantibody was substantiated in 2 other combinations in which little or no alloantibodies to donor spleen cells were produced. Engraftment of either MHC-identical but non-MHC disparate donor spleen cells into BALB/c nude mice or of parental spleen cells into F1 nude mice resulted in death mediated by T cells. In addition, irradiated BALB/c nude mice inoculated with non-MHC-incompatible B10.D2 spleen cells were much more sensitive to alloaggression by the donor cells than were nonirradiated hosts, indicating the presence of some radiation-sensitive component(s) acting in nude mice against GVHD induction by donor T cells. Thus the nude mouse is considered to be a useful recipient for clarifying the basic mechanisms involved in lethal GVHD.

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

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

    PubMed

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

    2011-01-01

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

  16. Graft-Derived Cell-Free DNA as a Marker of Transplant Graft Injury.

    PubMed

    Oellerich, Michael; Walson, Philip D; Beck, Julia; Schmitz, Jessica; Kollmar, Otto; Schütz, Ekkehard

    2016-04-01

    Although short-term success after solid organ transplantation is good, long-term graft and recipient survival are both not satisfactory. Despite therapeutic drug monitoring (TDM) of immunosuppressive drugs (ISDs), both excessive and insufficient immunosuppression still do occur. There is a need for new biomarkers that, when combined with TDM, can be used to provide more effective and less toxic, personalized immunosuppression to improve long-term survival. Currently used methods are insufficient to rapidly, cost-effectively, and directly interrogate graft integrity after solid organ transplantation. However, because organ transplants are also genome transplants, measurement of graft-derived circulating cell-free DNA (GcfDNA) has shown promise as a way to improve both graft and recipient outcomes after solid organ transplantation through the early detection of severe graft injury, enabling an early intervention. A newly developed droplet digital polymerase chain reaction (ddPCR) method has advantages over expensive high-throughput sequencing methods to rapidly quantify GcfDNA percentages and absolute amounts. This procedure does not require donor DNA and therefore can be applied to any organ donor/recipient pair. The droplet digital polymerase chain reaction method allows for the early, sensitive, specific, and cost-effective direct assessment of graft integrity and can be used to define individual responses to ISDs including the minimal ISD exposures necessary to prevent rejection. This is especially important in patients undergoing ISD switches due to ISD toxicity, infections, or malignancies. Although prospective, multicenter clinical trials in liver, heart, and kidney transplantation have not been completed, early results suggest that GcfDNA can be combined with TDM to guide changes in immunosuppression to provide more effective, and less toxic treatment. Personalized immunosuppression will shift emphasis in transplantation from reaction to prevention and could

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

    PubMed

    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

  18. Inability of donor total body irradiation to prolong survival of vascularized bone allografts: Experimental study in the rat

    SciTech Connect

    Gonzalez del Pino, J.; Benito, M.; Randolph, M.A.; Weiland, A.J. )

    1990-07-01

    At the present time, the toxic side effects of recipient immunosuppression cannot be justified for human non-vital organ transplantation. Total body irradiation has proven effective in ablating various bone-marrow-derived and endothelial immunocompetent cellular populations, which are responsible for immune rejection against donor tissues. Irradiation at a dose of 10 Gy was given to donor rats six days prior to heterotopic transplantation of vascularized bone allografts to host animals. Another group of recipient rats also received a short-term (sixth to fourteenth day after grafting), low dose of cyclosporine. Total body irradiation was able merely to delay rejection of grafts across a strong histocompatibility barrier for one to two weeks, when compared to nonirradiated allografts. The combination of donor irradiation plus cyclosporine did not delay the immune response, and the rejection score was similar to that observed for control allografts. Consequently, allograft viability was quickly impaired, leading to irreversible bone damage. This study suggest that 10 Gy of donor total body irradiation delivered six days prior to grafting cannot circumvent the immune rejection in a vascularized allograft of bone across a strong histocompatibility barrier.

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

    PubMed Central

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

    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 (aortoleft femoral) on the patient. This study reports a rare type of secondary aortoenteric fistula to the left colon, and it describes an unusual and successful surgical treatment. Antimicrobial coating of prosthetic vascular grafts may be a good alternative in the presence of graft infection associated with aortoenteric fistula because in situ grafts may carry an increased risk of reinfection. PMID:26880931

  20. Evolution of instruments for harvest of the skin grafts

    PubMed Central

    Ameer, Faisal; Singh, Arun Kumar; Kumar, Sandeep

    2013-01-01

    Background: The harvest of autologous skin graft is considered to be a fundamental skill of the plastic surgeon. The objective of this article is to provide an interesting account of the development of skin grafting instruments as we use them today in various plastic surgical procedures. Materials and Methods: The authors present the chronological evolution and modifications of the skin grafting knife, including those contributions not often cited in the literature, using articles sourced from MEDLINE, ancient manuscripts, original quotes, techniques and illustrations. Results: This article traces the evolution of instrumentation for harvest of skin grafts from free hand techniques to precise modern automated methods. Conclusions: Although skin grafting is one of the basic techniques used in reconstructive surgery yet harvest of a uniform graft of desired thickness poses a challenge. This article is dedicated to innovators who have devoted their lives and work to the advancement of the field of plastic surgery. PMID:23960303

  1. Radiation grafting of styrene on starch with high efficiency

    NASA Astrophysics Data System (ADS)

    Sheikh, N.; Akhavan, A.; Ataeivarjovi, E.

    2013-04-01

    Wheat starch grafted with polystyrene (PS-g-starch) was synthesized via polymerization grafting of styrene on starch by gamma-ray. The effects of starch/styrene weight ratio, and amount of applied doses (5-40 kGy) on the percentage of grafting, G (%), were investigated. The results showed that G (%) increased with increasing starch content. The optimum condition, starch/styrene weight ratio 1/3 and the applied dose 10 kGy, led to 252.9% of grafting. The obtained graft copolymer was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, and scanning electron microscopy. FTIR spectroscopy as well as the XRD analysis exhibited the changes in chemical and crystalline structure of starch after grafting reaction. TGA demonstrated the changes in thermal stability of PS-g-starch copolymer. SEM micrographs indicated porous patches of PS adhering on the starch.

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

    PubMed

    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.

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

    PubMed

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

    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 (aortoleft femoral) on the patient. This study reports a rare type of secondary aortoenteric fistula to the left colon, and it describes an unusual and successful surgical treatment. Antimicrobial coating of prosthetic vascular grafts may be a good alternative in the presence of graft infection associated with aortoenteric fistula because in situ grafts may carry an increased risk of reinfection. PMID:26880931

  4. Full-Thickness Skin Grafting in Nasal Reconstruction

    PubMed Central

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

    2013-01-01

    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. PMID:24872748

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

    NASA Astrophysics Data System (ADS)

    Çankaya, Nevin

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Electron beam induced grafting of N-isopropylacrylamide to a poly(ethylene-terephthalate) membrane for rapid cell sheet detachment

    NASA Astrophysics Data System (ADS)

    Chumakov, Marina K.; Shahamat, Layla; Weaver, Alia; LeBlanc, Jill; Chaychian, Mahnaz; Silverman, Joseph; Benjamin Richter, K.; Weiss, Douglas; Al-Sheikhly, Mohamad

    2011-02-01

    Intact sheets of human prostate epithelium cells were successfully detached from a poly(N-isopropylacrylamide) (pNIPAM) membrane radiolytically grafted to poly(ethlylene-terephthalate (PET) culture dishes. The detachment process took less than 20 min without damaging the sheet structure. The grafting was performed using a high-energy electron beam to covalently bond NIPAM to the surface of PET culture dishes. This work demonstrates that the optimal conditions for uniform grafting can be achieved by adding argon-saturated solutions of NIPAM monomer onto pre-irradiated, surface-activated PET membranes. The solutions and the membranes were then irradiated under anaerobic conditions to a total absorbed dose of 25 kGy. This grafting method involves producing carbon-centered free radicals NIPAM rad and PET rad from both NIPAM and PET, respectively. An investigation of the kinetics of the early stages of polymerization of NIPAM was performed through electron beam pulse radiolysis with optical detection. The pulse radiolysis experiments of anaerobic NIPAM methanol solutions show that the esolrad - reacts very rapidly with NIPAM producing NIPAM rad - anions with a reaction rate constant of 1.4×10 9±10% L mol -1 s -1. The NIPAM rad - anions then undergo a protonation reaction producing the initiation free radical (NIPAM rad ) with a reaction rate constant of 9×10 2 L mol -1 s -1. Along with pulse radiolysis, electron paramagnetic resonance (EPR) measurements show that the radiolytically produced carbon-centered free radicals of the PET, PET rad , decay following an overall observed pseudo-first-order reaction with rate constants of k=2.0×10 -4 and 7.0×10 -4 s -1 produced in argon and in air, respectively. The overall observed decay reaction involve PET rad +PET rad cross-linking, PET rad +O 2, PET+HO2rad , and PET+H-atoms, since these EPR measurements were conducted under aerobic conditions.

  8. Immunosuppression and organ transplantation tolerance using total lymphoid irradiation

    SciTech Connect

    Slavin, S.; Strober, S.; Fuks, Z.; Kaplan, H.S.

    1980-01-01

    Total lymphoid irradiation (TLI) is a method which delivers irradiation daily in fractionated doses (200 rads) to lymphoid organs while shielding bones, lungs, and the majority of the gastrointestinal tract. TLI is lymphocytopenic in mice, rats, dogs, and humans, and both T cells and B cells are eliminated from the circulation. TLI permits establishment of specific and long-lasting tolerance to alloantigens. Permanent acceptance of allogeneic bone marrow cells without graft-versus-host disease was achieved in rats and dogs across major histocompatibility barriers. Recipients were tolerant to allografts of skin, hearts, and kidney from animals syngeneic to marrow donors or to organs from the marrow donor. This approach may be suitable for pancreas transplantation in diabetes.

  9. Test reactor irradiation coordination

    SciTech Connect

    Heartherly, D.W.; Siman Tov, I.I.; Sparks, D.W.

    1995-10-01

    This task was established to supply and coordinate irradiation services needed by NRC contractors other than ORNL. These services include the design and assembly of irradiation capsules as well as arranging for their exposure, disassembly, and return of specimens. During this period, the final design of the facility and specimen baskets was determined through an iterative process involving the designers and thermal analysts. The resulting design should permit the irradiation of all test specimens to within 5{degrees}C of their desired temperature. Detailing of all parts is ongoing and should be completed during the next reporting period. Procurement of the facility will also be initiated during the next review period.

  10. Alaskan Commodities Irradiation Project

    SciTech Connect

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.; Das, D.K.; Lewis, C.E.; Workman, W.G.; Tumeo, M.A.; Hok, C.I.; Birklid, C.A.; Bennett, F.L.

    1988-12-01

    The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology. 40 refs., 50 figs., 53 tabs.

  11. Segmental pancreatic allograft survival in baboons treated with combined irradiation and cyclosporine: a preliminary report

    SciTech Connect

    du Toit, D.F.; Heydenrych, J.J.; Smit, B.; Louw, G.; Zuurmond, T.; Laker, L.; Els, D.; Weideman, A.; Wolfe-Coote, S.; van der Merwe, E.A.

    1985-04-01

    The present study was undertaken to evaluate the effectiveness of cyclosporine (CS) alone, total lymphoid irradiation (TLI) alone, and CS in combination with total body irradiation (TBI) in suppressing segmental pancreatic allograft rejection in totally pancreatectomized outbred chacma baboons. The administration of CS 25 mg/kg/day and 50 mg/ kg/day resulted in mean graft survival of 21.5 days and 24.5 days, respectively. CS 85 mg/kg/day resulted in median graft survival of 9 days. There was a wide daily fluctuation of CS serum trough levels exhibited between primates receiving the same oral dose. TBI in excess of 300 rads resulted in irreversible bone marrow suppression. Modest results were achieved in recipients of TBI-76 rads (38 x 2 rads), with median graft survival of 21 days, results not different from recipients treated with CS. TLI recipients of 600 rads (150 x 4 rads) resulted in median pancreatic graft survival of 16 days. TBI together with oral CS administration exhibited no synergistic or additive effect and a single peroperative donor-specific blood transfusion did not enhance pancreatic allograft survival in this model. However, of 10 primates receiving TBI 100 rads (50 x 2 rads) and CS 25 mg/kg/day administered orally indefinitely, four remained normoglycemic for more than 60 days. TBI 100 rads (50 x 2 rads) together with oral and parenteral CS resulted in necrotizing enterocolitis in four of six recipients.

  12. Radiation grafting of acrylic acid onto polypropylene films

    NASA Astrophysics Data System (ADS)

    Taher, N. H.; Dessouki, A. M.; Khalil, F. H.

    A study has been made for the preparation of membranes by the direct radiation grafting of acrylic acid (AAc) onto polypropylene (PP) films. The appropriate reaction conditions were selected under which the graft polymerization was carried out successfully. The effect of different solvents such as benzene, methanol/water mixture, isopropanol/water mixture, dimethyl formalide and distilled water on the swelling and grafting process of AAc onto PP films was investigated. In this grafting system ammonium ferrous sulphate (Mohr's salt) and ferric chloride were used as inhibitors to minimize the homopolymerization of AAc and the suitable concentration of the inhibitor was found to be 1.0 and 1.5 wt% for Mohr's salt and ferric chloride, respectively. Also, the effect of monomer concentration on the rate of grafting was investigated. The dependence of the grafting rate on monomer concentration was found to be 1.1 order. This grafting system proceeded by diffusion controlled process. Some selected properties of the grafted films such as swelling behavior, gel determination, mechanical and electrical properties were also investigated. It was found that the grafted membranes possess good hydrophilic properties which may make them promising in some practical applications.

  13. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen, that is intended to fill, augment, or reconstruct periodontal or bony...

  14. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen, that is intended to fill, augment, or reconstruct periodontal or bony...

  15. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen, that is intended to fill, augment, or reconstruct periodontal or bony...

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

    PubMed Central

    Zhang, Jing; Chen, Sumei; Liu, Ruixia; Jiang, Jiafu; Chen, Fadi; Fang, Weimin

    2013-01-01

    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. PMID:23878523

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

    PubMed

    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.

  18. A rapid, reproducible, noninvasive predictor of liver graft survival

    PubMed Central

    Zarrinpar, Ali; Lee, Coney; Noguchi, Emily; Yersiz, Hasan; Agopian, Vatche G.; Kaldas, Fady M.; Farmer, Douglas G.; Busuttil, Ronald W.

    2016-01-01

    Background Clinical and laboratory criteria are not reliable predictors of deceased donor liver graft quality. Intraoperative assessment of experienced surgeons is the gold standard. Standardizing and quantifying this assessment is especially needed now that regional sharing is the rule. We prospectively evaluated a novel, simple, rapid, noninvasive, quantitative measure of liver function performed before graft procurement. Materials and methods Using a portable, finger-probe–based device, indocyanine green plasma disappearance rates (ICG-PDR) were measured in adult brain-dead donors in the local donor service area before organ procurement. Results were compared with graft function and outcomes. Both donor and recipient teams were blinded to ICG-PDR measurements. Results Measurements were performed on 53 consecutive donors. Eleven liver grafts were declined by all centers because of quality; the other 42 grafts were transplanted. Logistic regression analysis showed ICG-PDR to be the only donor variable to be significantly associated with 7-d graft survival. Donor risk index, donor age, and transaminase levels at peak or procurement were not significantly associated with 7-d graft survival. Conclusions We report the successful use of a portable quantitative means of measuring liver function and its association with graft survival. These data warrant further exploration in a variety of settings to evaluate acceptable values for donated liver grafts. PMID:25940156

  19. Implantation of Vascular Grafts Lined with Genetically Modified Endothelial Cells

    NASA Astrophysics Data System (ADS)

    Wilson, James M.; Birinyi, Louis K.; Salomon, Robert N.; Libby, Peter; Callow, Allan D.; Mulligan, Richard C.

    1989-06-01

    The possibility of using the vascular endothelial cell as a target for gene replacement therapy was explored. Recombinant retroviruses were used to transduce the lacZ gene into endothelial cells harvested from mongrel dogs. Prosthetic vascular grafts seeded with the genetically modified cells were implanted as carotid interposition grafts into the dogs from which the original cells were harvested. Analysis of the graft 5 weeks after implantation revealed genetically modified endothelial cells lining the luminal surface of the graft. This technology could be used in the treatment of atherosclerosis disease and the design of new drug delivery systems.

  20. Dialysis needle puncture of Wallgrafts placed in polytetrafluoroethylene hemodialysis grafts.

    PubMed

    Rhodes, Erik S; Silas, Anne M

    2005-08-01

    This study evaluates the effect of routine venipuncture at hemodialysis on the durability of Wallgraft covered stents. Thirteen covered stents were placed in six aging, failing polytetrafluoroethylene grafts for treatment of pseudoaneurysms and recurrent stenoses. Four patients did not experience significant graft complications. One graft was ligated for an infected overlying skin ulcer. After surgical revision, the graft remains functional. Another patient experienced fraying of the stent edges and recurrence of a small pseudoaneurysm. Our experience suggests that the Wallgraft covered stent can withstand routine venipuncture at dialysis without flow-limiting stent distortion.

  1. Chevron bone graft procedure for the correction of brachymetatarsia.

    PubMed

    Alter, S A; Feinman, B; Rosen, R G

    1995-01-01

    Brachymetatarsia is a relatively rare condition, although there are many surgical procedures to correct the condition. The authors present a case study with a 2-year follow-up period demonstrating the successful surgical treatment of a 4th metatarsal brachymetatarsia of the left foot of a 14-year-old female. The operative technique and literature review are discussed. This technique combines the idea of bone grafting with a specific graft shape and donor site to facilitate graft stability and graft healing. PMID:7599619

  2. PDMS content affects in vitro hemocompatibility of synthetic vascular grafts.

    PubMed

    Spiller, Dario; Losi, Paola; Briganti, Enrica; Sbrana, Silverio; Kull, Silvia; Martinelli, Ilaria; Soldani, Giorgio

    2007-06-01

    An unsolved problem when employing small-diameter vascular grafts for aorto-coronary by-pass and peripheral reconstruction is the early thrombotic occlusion. The PEtU-PDMS is a new elastomeric material, composed of poly(ether)urethane and polydimethylsiloxane, synthesized to realize grafts with improved hemocompatibility characteristics. In order to investigate the effect of PDMS content on hemocompatibility, three different percentages of PDMS containing grafts (10, 25 and 40) were evaluated. Grafts realized with Estane 5714-F1 and silicone medical grade tubes were used as references. The hemocompatibility was investigated by an in vitro circuit in which human anticoagulated blood was circulated into grafts by a peristaltic pump modified to obtain a passive flow. For each experiment, 40 cm length graft was closed into a circular loop and put in rotation for 2 h at 37 degrees C. At the end of the experiments different parameters regarding platelet adhesion and activation were evaluated: circulating platelets count, beta-thromboglobulin release, platelet CD62P expression and amount of monocyte-platelet conjugates. PEtU-PDMS grafts with 25 and 40% of PDMS induced the lowest platelet adhesion, plasma level of beta-TG and amount of monocyte-platelet conjugates. No significative variations were observed in CD62P expression. In conclusion, PDMS content significatively affects blood-graft surface interaction, in fact higher PDMS percentage containing grafts showed the best in vitro hemocompatibility. PMID:17268875

  3. Chrysanthemum cutting productivity and rooting ability are improved by grafting.

    PubMed

    Zhang, Jing; Chen, Sumei; Liu, Ruixia; Jiang, Jiafu; Chen, Fadi; Fang, Weimin

    2013-01-01

    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. PMID:23878523

  4. Experience of vein grafting in Göttingen minipigs.

    PubMed

    Tsutsumi, H; Miyawaki, F; Arakawa, H; Tsuji, T; Tanigawa, M

    2001-04-01

    We experimented with vein grafting surgery on Göttingen minipigs. Using the internal jugular vein for the tissue graft, we performed side-to-side anastomosis to the carotid artery, to which it runs parallel. One key point in this surgery was to prevent vasospasm of the carotid artery so as to keep the lumen sufficiently patent during anastomosis. The histopathological findings in the grafts which remained patent resembled those of vein grafts in humans. We therefore considered that this technique in minipigs can be applied for the study of coronary artery bypass surgery in humans.

  5. Nerve repair and cable grafting for facial paralysis.

    PubMed

    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. T cell–depleted stem-cell transplantation for adults with hematologic malignancies: sustained engraftment of HLA-matched related donor grafts without the use of antithymocyte globulin

    PubMed Central

    Small, Trudy N.; Young, James W.; Kernan, Nancy A.; Castro-Malaspina, Hugo; Hsu, Katherine C.; Perales, Miguel-Angel; Collins, Nancy; Cisek, Christine; Chiu, Michelle; van den Brink, Marcel R. M.; O'Reilly, Richard J.; Papadopoulos, Esperanza B.

    2007-01-01

    Antithymocyte globulin (ATG) has been used in allogeneic stem-cell transplantation to prevent graft rejection and graft-versus-host disease (GvHD). Its use, however, has been associated with delayed T-cell reconstitution and prolonged susceptibility to opportunistic infections (OIs) especially in patients undergoing T cell–depleted (TCD) transplantation. Recently, a prospective trial was conducted in 52 adult patients (median age, 47 years) with various hematologic malignancies undergoing TCD transplantation from HLA-matched related donors without the use of ATG. The cytoreductive regimen consisted of hyperfractionated total body irradiation (HFTBI), thiotepa, and fludarabine. The preferred source of the graft was peripheral blood stem cells (PBSCs). No additional graft rejection or GvHD prophylaxis was given. All evaluable patients engrafted without any immune-mediated graft rejections. Disease-free survival (DFS) at 3 years was 61% in all patients, and 70% in patients with standard-risk disease. Acute GvHD was limited to grade 2 in 8% and chronic GvHD in 9% of patients. Life-threatening OIs occurred in 3 of 52 patients and was fatal in 1. This study demonstrates durable engraftment with a low incidence of GvHD despite the lack of ATG, as well as the curative potential of this regimen. PMID:17717135

  7. Separation of copper ions from iron ions using PVA-g-(acrylic acid/N-vinyl imidazole) membranes prepared by radiation-induced grafting.

    PubMed

    Ajji, Zaki; Ali, Ali M

    2010-01-15

    Acrylic acid (AAc), N-vinyl imidazole (Azol) and their binary mixtures were graft copolymerized onto poly(vinyl alcohol) membranes using gamma irradiation. The ability of the grafted membranes to separate Cu ions from Fe ions was investigated with respect to the grafting yield and the pH of the feed solution. The data showed that the diffusion of copper ions from the feed compartment to the receiver compartment depends on the grafting yield of the membranes and the pH of the feed solution. To the contrary, iron ions did not diffuse through the membranes of all grafting yields. However, a limited amount of iron ions diffused in strong acidic medium. This study shows that the prepared membranes could be considered for the separation of copper ions from iron ions. The temperature of thermal decomposition of pure PVA-g-AAc/Azol membrane, PVA-g-AAc/Azol membrane containing copper ions, and PVA-g-AAc/Azol membrane containing iron ions were determined using TGA analyzer. It was shown that the presence of Cu and Fe ions increases the decomposition temperature, and the membranes bonded with iron ions are more stable than those containing copper ions. PMID:19836882

  8. Acrylation of pre-irradiated polypropylene and its application for removal of organic pollutants

    NASA Astrophysics Data System (ADS)

    Said, Hossam M.; Sokker, Hesham H.; El-Hag Ali, Amr

    2010-04-01

    Reactive extrusion of pre-irradiated polypropylene (PP) at different doses of gamma radiation was studied in the presence of different concentrations of acrylic acid monomer (AAc). Preliminary investigations study the feasibility or removal of organic pollutants. The optical properties and surface morphology of the grafted polypropylene were observed by FT-IR, UV/vis and scanning electron microscopy (SEM). The affinity of this membrane to the basic dye was found to be increased with increase in the dose of gamma irradiation and the ratio of acrylic acid monomer (AAc).

  9. Economics of food irradiation

    SciTech Connect

    Deitch, J.

    1982-01-01

    This article examines the cost competitiveness of the food irradiation process. An analysis of the principal factors--the product, physical plant, irradiation source, and financing--that impact on cost is made. Equations are developed and used to calculate the size of the source for planned product throughput, efficiency factors, power requirements, and operating costs of sources, radionuclides, and accelerators. Methods of financing and capital investment are discussed. A series of tables show cost breakdowns of sources, buildings, equipment, and essential support facilities for both a cobalt-60 and a 10-MeV electron accelerator facility. Additional tables present irradiation costs as functions of a number of parameters--power input, source size, dose, and hours of annual operation. The use of the numbers in the tables are explained by examples of calculations of the irradiation costs for disinfestation of grains and radicidation of feed.

  10. Graft copolymerization onto polybutadiene: Cross-linking and thermal degradation of vinyl polymers and copolymers

    NASA Astrophysics Data System (ADS)

    Jiang, Dayue (David)

    This work consists of three parts. In Part I, the graft copolymerization of methyl methacrylate, methyl acrylate, methacylic acid and acrylic acid onto polybutadiene and its copolymers by benzoyl peroxide, BPO, or 2, 2'azobis(2-methylpropionitrile), AIBN, initiation were explored. The results show that these monomers can be grafted onto butadiene region of butadiene-containing polymers. The extent of both graft copolymerization and homopolymerization are dependent on the time and temperature of the reaction and the concentration of all of the reactants. One must specify the monomer, initiator and solvent for the efficient graft copolymerization. The methyl methacrylate adds directly to the radical sites which are formed on the backbone by the interaction of the polymer and the primary radical form the initiator, while for the other three monomers, the graft copolymerization occurs by addition of macro-radical to the double bonds. In Part II, the cross-linking of polybutadiene, butadiene-styrene copolymers, and polystyrene by irradiation, thermal and chemical processes, and Friedel-Crafts chemistry and the effect of cross-linking on the thermal stability were investigated. The proof of cross-linking of the polymer comes from the insolubility of the product after the cross-linking reaction and is characterized by gel content and swelling ratio. The results show that the thermal stability of the polymer can be improved by cross-linking. In Part III, the thermal degradation of three vinyl polymers, poly(vinylsulfonic acid) and its sodium salt and poly(vinylphosphonic acid) were studied by combination technique: TGA/FTIR. The results show that TGA/FTIR combined with analysis of residues provides an excellent opportunity to understand the degradation pathway of the compounds. The observation of foaming indicates that the char which is formed contains carbon as well as the inorganic salts which have been observed. The carbon is in a partially graphitized form. The salts

  11. Kidney allograft survival in dogs treated with total lymphoid irradiation

    SciTech Connect

    Howard, R.J.; Sutherland, D.E.R.; Lum, C.T.; Lewis, W.I.; Kim, T.H.; Slavin, S.; Najarian, J.S.

    1981-02-01

    Total lymphoid irradiation (TLI) is immunosuppressive and, in rodents, can induce a state where transplantation of allogenic bone marrow results in chimerism and permanent acceptance of organ allografts from the donor strain. Twelve splenectomized dogs were treated with TLI (150 rads per fraction, total dose 1950 to 3000 rads) before bilateral nephrectomy and renal allotransplantation. Eight dogs received bone marrow from the kidney donor. In 13 untreated control dogs renal allografts functioned for a mean +- (SE) of 4.7 +- 0.3 days. In the four TLI treated dogs who did not receive bone marrow the renal allografts functioned for 15 to 76 days (two dogs died with functioning grafts). In the eight TLI treated dogs who received donor bone marrow, two died immediately after transplantation, two rejected at 3 and 13 days, one died at 13 days with a functioning graft, and two have had the grafts function for longer than 500 days. Chimerism was not detected in the one dog tested. The response of peripheral blood lymphocytes to stimulation with phytohemaglutinin and in mixed lymphocyte culture was suppressed for at least one month after TLI. The results confirm the immunosuppressive effect of TLI. The absence of kidney rejection in two recipients of donor bone marrow show the potential of this approach to induce long-term immunologic unresponsiveness as to an organ allograft, but the outcome is unpredictable and further experiments are needed to define the optimal conditions for administration of TLI and bone marrow to the recipients.

  12. Insitu grafting silica nanoparticles reinforced nanocomposite hydrogels

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

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

    SciTech Connect

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

    2009-01-15

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

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

    PubMed

    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.

  15. Bone scintigraphy in evaluating the viability of composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and free non-revascularized periosteal grafts

    SciTech Connect

    Berggren, A.; Weiland, A.J.; Ostrup, L.T.

    1982-07-01

    Researchers studied the value of bone scintigraphy in the assessment of anastomotic patency and bone-cell viability in free bone grafts revascularized by microvascular anastomoses in twenty-seven dogs. The dogs were divided into three different groups, and scintigraphy was carried out using technetium-labeled methylene diphosphonate in composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and periosteal grafts placed in different recipient beds. The viability of the grafts were evaluated by histological examination and fluorescence microscopy after triple labeling with oxytetracycline on the first postoperative day, alizarin complexone on the fourth postoperative day, and DCAF on the eleventh postoperative day. A positive scintiscan within the first week following surgery indicated patent microvascular anastomoses, and histological study and fluorescence microscopy confirmed that bone throughout the graft was viable. A positive scintiscan one week after surgery or later does not necessarily indicate microvascular patency or bone-cell survival, because new bone formed by creeping substitution on the surface of a dead bone graft can result in this finding.

  16. Synthesis of grafted polyamide/polyglutarimide blends

    SciTech Connect

    Hallden-Abberton, M.

    1993-12-31

    Polyglutarimides are high Tg thermoplastics, prepared by a reactive extrusion process involving polymethylmethacrylate and primary amines in a plasticating extruder at high pressures and temperatures. The resulting polymers can be synthesized with various levels of carboxylic acid and/or anhydride functionality as part of the polyglutarimide polymer. In a recent discovery, these polymers can be grafted to polyamides in a highly efficient manner by means of a reactive extrusion process. This talk will discuss the synthesis of these blends and techniques for their analysis. Partial fractionation, and spectroscopic analysis of these materials was used to monitor the reaction. The effects of extrusion temperature and catalyst level will be presented.

  17. Autologus parietal grafts in preprosthethic surgery

    PubMed Central

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

    2010-01-01

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

  18. Osteogenic activity of bone marrow-derived mesenchymal stem cells (BMSCs) seeded on irradiated allogenic bone.

    PubMed

    Tohma, Yasuaki; Dohi, Yoshiko; Ohgushi, Hajime; Tadokoro, Mika; Akahane, Manabu; Tanaka, Yasuhito

    2012-02-01

    Allogenic bone grafting, a technique used in orthopaedic surgery, has several problems, including low osteogenic activity. To overcome the problem, this study aimed to determine whether in vivo osteogenesis could be enhanced using allogenic irradiated bone grafts after seeding with autologous bone marrow-derived mesenchymal stem cells (BMSCs). The allogenic bone cylinders were extracted from ACI rats and sterilized by irradiation. Donor BMSCs were obtained from fresh Fischer 344 (F344) rat bone marrow by cell culture. The allogenic bone with or without BMSCs were transplanted subcutaneously into syngeneic F344 rats. At 4 weeks after transplantation, high alkaline phosphatase (ALP) activity, bone-specific osteocalcin mRNA expression and newly formed bone were detected in the allogenic bone with BMSCs. The origin of the newly formed bone was derived from cultured donor BMSCs. However, none of these identifiers of osteogenesis were detected in either the fresh or the irradiated allogenic bone without BMSCs. These results indicate the availability of autologous BMSCs to heighten the osteogenic response of allogenic bone. Our present tissue-engineering method might contribute to a wide variety of allogenic bone grafting techniques in clinical settings.

  19. Superoxide generation and cytotactic response of irradiated neutrophils

    SciTech Connect

    Eastlund, D.T.; Charbonneau, T.T.

    1988-07-01

    Irradiation of blood components has been used to prevent transfusion-related graft-versus-host disease (GVHD) in immunocompromised patients. This study was designed to determine the effect of irradiation on neutrophil aggregation, chemotaxis, and superoxide generation. Purified neutrophils were irradiated with a Cesium source at four doses ranging from 0 to 17,500 rads. Formyl-methionyl-leucyl-phenylalanine (FMLP) and zymosan-treated serum (ZTS) cytotaxin-induced chemotaxis and migration were determined in the agarose assay. Neutrophil aggregation to FMLP was determined by aggregometry. Superoxide generation and random migration were not affected by irradiation at doses up to 17,500 rads. When compared to nonirradiated controls, the chemotactic response to ZTS remained normal, with an insignificant decline from 174 +/- 31.0 to 150 +/- 42.3 (mean +/- SD) units. The chemotactic response to FMLP declined insignificantly, from 228 +/- 31.3 at 0 rad to 207 +/- 26.4 at 17,500 rads. The aggregation response to FMLP remained within the normal range but declined from 0.78 +/- 0.11 to 0.61 +/- 0.18. At the radiation doses currently used to reduce the risk of transfusion-related GVHD, neutrophil superoxide generation and chemotactic response remain essentially normal.

  20. Irradiation and food processing.

    PubMed

    Sigurbjörnsson, B; Loaharanu, P

    1989-01-01

    After more than four decades of research and development, food irradiation has been demonstrated to be safe, effective and versatile as a process of food preservation, decontamination or disinfection. Its various applications cover: inhibition of sprouting of root crops; insect disinfestation of stored products, fresh and dried food; shelf-life extension of fresh fruits, vegetables, meat and fish; destruction of parasites and pathogenic micro-organisms in food of animal origin; decontamination of spices and food ingredients, etc. Such applications provide consumers with the increase in variety, volume and value of food. Although regulations on food irradiation in different countries are largely unharmonized, national authorities have shown increasing recognition and acceptance of this technology based on the Codex Standard for Irradiated Foods and its associated Code of Practice. Harmonization of national legislations represents an important prerequisite to international trade in irradiated food. Consumers at large are still not aware of the safety and benefits that food irradiation has to offer. Thus, national and international organizations, food industry, trade associations and consumer unions have important roles to play in introducing this technology based on its scientific values. Public acceptance of food irradiation may be slow at the beginning, but should increase at a faster rate in the foreseeable future when consumers are well informed of the safety and benefits of this technology in comparison with existing ones. Commercial applications of food irradiation has already started in 18 countries at present. The volume of food or ingredients treated on a commercial scale varies from country to country ranging from several tons of spices to hundreds of thousands of tons of grains per annum. With the increasing interest of national authorities and the food industry in applying the process, it is anticipated that some 25 countries will use some 55 commercial