Science.gov

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 peritoneal dialysis and graft thrombosis following pediatric kidney transplantation: a NAPRTCS report.

    PubMed

    McDonald, Ruth A; Smith, Jodi M; Stablein, Donald; Harmon, William E

    2003-06-01

    Graft thrombosis is a common cause of graft failure in pediatric renal transplantation. Several previous studies, including a North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) review of pretransplant dialysis status and graft outcomes, have described a potential correlation of peritoneal dialysis (PD) and graft thrombosis. This issue is of particular concern for pediatric transplant programs as more than 65% of children with end stage renal disease are treated with PD. We reviewed 7247 pediatric renal transplants performed between 1987 and 2001. Thrombosis was the cause of graft loss in 2.7% (199) of all the transplants performed. Among failed transplants, thrombosis was the third most common cause of graft loss in both index (11.6%) and subsequent transplants (14.5%). Thrombosis becomes the most common cause of graft failure (21%, 61/294) if one looks at transplants in the later cohort, from 1996 to 2001. This change is primarily because of a decrease in the incidence of acute rejection. In the PD group, 3.4% of all grafts were lost as a result of thrombosis. This compares with 1.9% in the hemodialysis group, 2.4% in the pre-emptive transplant group, and 4.1% among patients who received both dialysis modalities. There was a statistically significant difference in thrombosis failure risk in the different dialysis groups (p = 0.005) with those who received only peritoneal dialysis having the highest risk. Additional significant risk factors for graft thrombosis included; cadaver donor source (p < 0.001), cold ischemia time >24 h (p < 0.001), history of prior transplant (p < 0.001), donor age <6 yr (p < 0.001), and >5 pretransplant blood transfusions (p = 0.02). Using stepwise proportional hazards modeling, only pretransplant peritoneal dialysis, >24 h cold ischemia time, prior transplant, and donor age <6 yr were simultaneously associated with an increased risk of thrombosis. We conclude that pretransplant PD is associated with an increased risk

  3. Mesenchymal stromal cells and kidney transplantation: pretransplant infusion protects from graft dysfunction while fostering immunoregulation.

    PubMed

    Perico, Norberto; Casiraghi, Federica; Gotti, Eliana; Introna, Martino; Todeschini, Marta; Cavinato, Regiane Aparecida; Capelli, Chiara; Rambaldi, Alessandro; Cassis, Paola; Rizzo, Paola; Cortinovis, Monica; Noris, Marina; Remuzzi, Giuseppe

    2013-09-01

    Bone marrow-derived mesenchymal stromal cells (MSC) have emerged as useful cell population for immunomodulation therapy in transplantation. Moving this concept towards clinical application, however, should be critically assessed by a tailor-made step-wise approach. Here, we report results of the second step of the multistep MSC-based clinical protocol in kidney transplantation. We examined in two living-related kidney transplant recipients whether: (i) pre-transplant (DAY-1) infusion of autologous MSC protected from the development of acute graft dysfunction previously reported in patients given MSC post-transplant, (ii) avoiding basiliximab in the induction regimen improved the MSC-induced Treg expansion previously reported with therapy including this anti-CD25-antibody. In patient 3, MSC treatment was uneventful and graft function remained normal during 1 year follow-up. In patient 4, acute cellular rejection occurred 2 weeks post-transplant. Both patients had excellent graft function at the last observation. Circulating memory CD8(+) T cells and donor-specific CD8(+) T-cell cytolytic response were reduced in MSC-treated patients, not in transplant controls not given MSC. CD4(+) FoxP3(+) Treg expansion was comparable in MSC-treated patients with or without basiliximab induction. Thus, pre-transplant MSC no longer negatively affect kidney graft at least to the point of impairing graft function, and maintained MSC-immunomodulatory properties. Induction therapy without basiliximab does not offer any advantage on CD4(+) FoxP3(+) Treg expansion (ClinicalTrials.gov number: NCT 00752479). PMID:23738760

  4. Renal graft irradiation in acute rejection

    SciTech Connect

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

    1983-03-01

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

  5. 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

  6. Pretransplant β2-Microglobulin Is Associated with the Risk of Acute Graft-versus-Host-Disease after Allogeneic Hematopoietic Cell Transplant.

    PubMed

    Costa-Lima, Carolina; Miranda, Eliana Cristina Martins; Colella, Marcos Paulo; Aranha, Francisco Jose Penteado; de Souza, Carmino Antonio; Vigorito, Afonso Celso; De Paula, Erich Vinicius

    2016-07-01

    The risk of acute graft-versus-host disease (aGVHD) can be reliably estimated by the hematopoietic cell transplantation-specific comorbidity index (HCT-CI), which can be further refined by the incorporation of pre-hematopoietic cell transplantation (HCT) serum levels of inflammatory biomarkers such as ferritin and albumin. β2-Microglobulin (β2-m) is a key component of the MHC class I complex, which is independently associated with mortality and frailty in the general population. We took advantage of our institutional protocol that includes measurement of pre-HCT β2-m serum levels in the most patients to investigate whether pre-transplant β2-m levels were associated with the risk of aGVHD. One hundred three consecutive patients submitted to allogeneic HCT, of which 26 developed grades II to IV aGVHD, were included in the analysis. β2-m was significantly associated with age and HCT-CI. Higher levels of β2-m were observed in patients who developed aGVHD (P = .008). In the multivariate Cox regression model, β2-m and HCT-CI remained independently associated with the risk of developing aGVHD. In conclusion, the association between β2-m and the occurrence of aGVHD suggests that the measurement of this protein before HCT might represent an additional element for risk stratification of aGVHD. PMID:27044906

  7. Pre-transplant angiotensin II type 1receptor antibodies: a risk factor for decreased kidney graft function in the early post-transplant period?

    PubMed

    Hernández-Méndez, Erick Alejandro; Arreola-Guerra, José Manuel; Morales-Buenrostro, Luis E; Ramírez, Julia B; Calleja, Said; Castelán, Natalia; Salcedo, Isaac; Vilatobá, Mario; Contreras, Alan G; Gabilondo, Bernardo; Granados, Julio; Alberú, Josefina

    2014-01-01

    Angiotensin II type 1 receptor antibodies (AT1Rab) are associated to a significantly lower graft survival and a higher risk of acute rejection after kidney transplantation. This study aimed to evaluate graft function and BPAR during the 1st year post-transplant (PT) in adult kidney transplant recipients (KTR), between 03/2009 and 08/2012. Pre-KT sera were screened for AT1Rab (ELISA) and HLA-DSA (Luminex). Three groups were analyzed: AT1Rab only (n = 13); HLA-DSA only (n = 8); and no AT1Rab or HLA-DSA (n = 90). No differences were observed in clinical characteristics across groups. A higher percentage of BPAR was observed in the AT1Rab positive group, but this difference was not significant. KTR with AT1Rab had a lower mean eGFR (20 mL/min/1.73m2) when compared to KTR with no Abs at 12 months. The significant difference in eGFR was observed since the 1st month PT. Multivariate analysis showed 4 factors independently and significantly associated with eGFR at 12mos PT: BPAR (-18.7 95%, CI -28.2 to -9.26, p<0.001), AT1Rab (-10.51, CI -20.9 to -0.095, p = 0.048), donor age (-0.42, CI -0.75 to -0.103 p = 0.010), and recipient age (-0.36, CI -0.67 to -0.048, p = 0.024). In this study AT1Rab in pre-transplant sera from KTR, was an independent and significant risk factor contributing to a lower eGFR 12 months. PT. This finding deserves to be confirmed in a larger KTR population. PMID:25695237

  8. The Kidney Donor Profile Index (KDPI) of marginal donors allocated by standardized pretransplant donor biopsy assessment: distribution and association with graft outcomes.

    PubMed

    Gandolfini, I; Buzio, C; Zanelli, P; Palmisano, A; Cremaschi, E; Vaglio, A; Piotti, G; Melfa, L; La Manna, G; Feliciangeli, G; Cappuccilli, M; Scolari, M P; Capelli, I; Panicali, L; Baraldi, O; Stefoni, S; Buscaroli, A; Ridolfi, L; D'Errico, A; Cappelli, G; Bonucchi, D; Rubbiani, E; Albertazzi, A; Mehrotra, A; Cravedi, P; Maggiore, U

    2014-11-01

    Pretransplant donor biopsy (PTDB)-based marginal donor allocation systems to single or dual renal transplantation could increase the use of organs with Kidney Donor Profile Index (KDPI) in the highest range (e.g. >80 or >90), whose discard rate approximates 50% in the United States. To test this hypothesis, we retrospectively calculated the KDPI and analyzed the outcomes of 442 marginal kidney transplants (340 single transplants: 278 with a PTDB Remuzzi score<4 [median KDPI: 87; interquartile range (IQR): 78-94] and 62 with a score=4 [median KDPI: 87; IQR: 76-93]; 102 dual transplants [median KDPI: 93; IQR: 86-96]) and 248 single standard transplant controls (median KDPI: 36; IQR: 18-51). PTDB-based allocation of marginal grafts led to a limited discard rate of 15% for kidneys with KDPI of 80-90 and of 37% for kidneys with a KDPI of 91-100. Although 1-year estimated GFRs were significantly lower in recipients of marginal kidneys (-9.3, -17.9 and -18.8 mL/min, for dual transplants, single kidneys with PTDB score<4 and =4, respectively; p<0.001), graft survival (median follow-up 3.3 years) was similar between marginal and standard kidney transplants (hazard ratio: 1.20 [95% confidence interval: 0.80-1.79; p=0.38]). In conclusion, PTDB-based allocation allows the safe transplantation of kidneys with KDPI in the highest range that may otherwise be discarded. PMID:25155294

  9. The Kidney Donor Profile Index (KDPI) of Marginal Donors Allocated by Standardized Pre-Transplant Donor Biopsy Assessment: Distribution and Association with Graft Outcomes

    PubMed Central

    Gandolfini, I.; Buzio, C.; Zanelli, P.; Palmisano, A.; Cremaschi, E.; Vaglio, A.; Piotti, G.; Melfa, L.; La Manna, G.; Feliciangeli, G.; Cappuccilli, M.; Scolari, M.P.; Capelli, I.; Panicali, L.; Baraldi, O.; Stefoni, S.; Buscaroli, A.; Ridolfi, L.; D'Errico, A.; Cappelli, G.; Bonucchi, D.; Rubbiani, E.; Albertazzi, A.; Mehrotra, A.; Cravedi, P.; Maggiore, U.

    2015-01-01

    Pre-transplant donor biopsy (PTDB)-based marginal-donor allocation systems to single or dual renal transplantation could increase the use of organs with Kidney Donor Profile Index (KDPI) in the highest range (e.g. >80 or >90), whose discard rate approximates 50% in the US. To test this hypothesis, we retrospectively calculated the KDPI and analyzed the outcomes of 442 marginal kidney transplants (340 single transplants: 278 with a PTDB Remuzzi score <4 [median KDPI:87; interquartile range(IQR):78-94] and 62 with a score =4 [median KDPI:87; IQR:76-93]; 102 dual transplants [median KDPI: 93; IQR:86-96]) and 248 single standard transplant controls [median KDPI:36; IQR:18-51]. PTDB-based allocation of marginal grafts led to a limited discard rate of 15% for kidneys with KDPI of 80-90 and of 37% for kidneys with a KDPI of 91-100. Although 1-year eGFRs were significantly lower in recipients of marginal kidneys (-9.3, -17.9, and -18.8ml/min, for dual transplants, single kidneys with PTDB score <4, and =4, respectively; P<0.001), graft survival (median follow-up 3.3 years) was similar between marginal and standard kidney transplants (hazard ratio: 1.20 [95% confidence interval: 0.80 to 1.79; P=0.38]). In conclusion, PTDB-based allocation allows the safe transplantation of kidneys with KDPI in the highest range that may otherwise be discarded. PMID:25155294

  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. 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

  12. 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.

  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. 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.

  15. 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.

  16. Li + grafting of ion irradiated polyethylene

    NASA Astrophysics Data System (ADS)

    Švorčík, V.; Rybka, V.; Vacík, J.; Hnatowicz, V.; Öchsner, R.; Ryssel, H.

    1999-02-01

    Foils of oriented polyethylene (PE) were irradiated with 63 keV Ar + and 155 keV Xe + ions to different fluences at room temperature and then doped from water solution of LiCl. The as irradiated and irradiated plus doped samples were examined by IR, EPR and neutron depth profiling (NDP) technique. The sheet resistance was also measured by the standard two points method. After Li salt doping of ion modified layer of PE, a reaction between degraded macromolecules and Li occur and thus a new chemical structure C-Li + is formed. Owing to the presence of these cations on the polymer chain, the irradiated plus doped layer exhibits higher electric conductivity compared to as-irradiated ones.

  17. Grafting of styrene into pre-irradiated fluoropolymer films: Influence of base material and irradiation temperature

    NASA Astrophysics Data System (ADS)

    Lappan, Uwe; Geißler, Uwe; Gohs, Uwe; Uhlmann, Steffi

    2010-10-01

    In this study, the influence of irradiation temperature on mechanical properties of three fluoropolymers and on grafting of styrene into the polymers by the pre-irradiation method was investigated. Electron paramagnetic resonance spectroscopy and infrared spectroscopy were used to characterize the irradiated polymers regarding trapped radical species and changes in the chemical structure, respectively. For poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) the irradiation temperature was found to be an important factor for tensile strength and elongation at break of the pre-irradiated film. No strong effect of irradiation temperature on the mechanical properties was noticed for poly(tetrafluoroethylene-co-ethylene) (ETFE); however the yield of grafting drops at high irradiation temperatures. Finally, mechanical properties of poly(tetrafluoroethylene) (PTFE) were found to be dramatically altered, even if the film was irradiated at elevated temperature.

  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. Stability of Grafted Polymer Nanoscale Films toward Gamma Irradiation.

    PubMed

    Borodinov, Nikolay; Giammarco, James; Patel, Neil; Agarwal, Anuradha; O'Donnell, Katie R; Kucera, Courtney J; Jacobsohn, Luiz G; Luzinov, Igor

    2015-09-01

    The present article focuses on the influence of gamma irradiation on nanoscale polymer grafted films and explores avenues for improvements in their stability toward the ionizing radiation. In terms of applications, we concentrate on enrichment polymer layers (EPLs), which are polymer thin films employed in sensor devices for the detection of chemical and biological substances. Specifically, we have studied the influence of gamma irradiation on nanoscale poly(glycidyl methacrylate) (PGMA) grafted EPL films. First, it was determined that a significant level of cross-linking was caused by irradiation in pure PGMA films. The cross-linking is accompanied by the formation of conjugated ester, carbon double bonds, hydroxyl groups, ketone carbonyls, and the elimination of epoxy groups as determined by FTIR. Polystyrene, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, dimethylphenylsilanol, BaF2, and gold nanoparticles were incorporated into the films and were found to mitigate different aspects of the radiation damage. PMID:26259102

  20. 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

  1. 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

  2. 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.

  3. 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

  4. Pretransplant cytotoxic conditioning produces effects consistent with clonal deletion mechanisms.

    PubMed

    Zheng, T L; Johnson, C P; Sutherland, D E

    1987-05-01

    A rat cardiac allograft model (ACl to Lewis) was used to investigate the clonal deletion theory. Twelve groups of Lewis recipients received various combinations of donor-specific blood transfusions (DSTs), immediate post-DST immunosuppression with azathioprine/prednisone, and low-dose cyclosporine (1 mg/kg/day) posttransplant. DSTs and cyclosporine together gave modest prolongation of graft survival (from 6.0 to 17 days). DSTs plus immediate post-DST immunosuppression followed by low-dose cyclosporine prolonged graft survival to an average of 45 days. Third-party transfusions alone and in combination with immunosuppression did not significantly prolong allograft survival. Postoperative cyclosporine was required for the expression of this effect suggesting that clonal depression rather than clonal deletion had occurred. Combining DSTs with brief but intense preoperative immunosuppression may be a more effective method of pretransplant conditioning than DSTs alone. PMID:3295388

  5. Pre-irradiation-induced graft reaction of maleic anhydride onto polypropylene

    NASA Astrophysics Data System (ADS)

    Tan, X. M.; Xu, Y. S.; Wang, C. L.

    2006-09-01

    The radiation induced graft polymerization is a well-known method to obtain new materials. Until recently, only conventional radiation sources, such as Co-60 and electron beams, were used. Moreover, part of the damage induced in polymers by heavy ions can produce active sites (peroxides and hydroperoxides) that are useful to initiate grafting reactions. Maleic anhydride (MAH) was grafted onto polypropylene (PP) wax with a number-average molecular weight (Mn) of 8000 by gamma pre-irradiation technique. Effects of total dose, monomer concentration, reaction time, and temperature on percentage of grafting are studied in detail. It is shown that the optimum conditions for grafting are temperature of 70 degrees C and total dose of 14.4 kGy. PP-g-MAH is characterized by infrared spectrum. Differential scanning calorimetry shows that the compatibility of PP-g-MAH is better than that of PP.

  6. 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.

  7. 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

  8. 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.

  9. Novel insights into pretransplant allosensitization in heart transplant recipients in the contemporary era of immunosuppression and rejection surveillance.

    PubMed

    Svobodova, Eva; Gazdic, Tomas; Kubanek, Milos; Vymetalova, Jevgenija; Voska, Ludek; Kment, Martin; Lanska, Vera; Kolesar, Libor; Urban, Marian; Netuka, Ivan; Pirk, Jan; Melenovsky, Vojtech; Kautzner, Josef; Slavcev, Antonij; Malek, Ivan

    2016-01-01

    Solid-phase assays (SPA) have facilitated detection and definition of antibodies to human leukocyte antigens (HLA) and major histocompatibility complex class I chain-related antigen A (MICA). However, clinical consequences of pretransplant SPA results in heart transplantation have been studied insufficiently in the current era of immunosuppression and rejection surveillance. Pretransplant sera, panel-reactive antibodies (PRA), pretransplant crossmatch, and clinical data were retrospectively analyzed in 264 adult heart transplant recipients. The specificity of HLA and MICA antibodies and C1q-binding activity of donor-specific antibodies (DSA) were defined using SPA. Pretransplant HLA antibodies were detected in 57 (22%) individuals, in 28 individuals (11%); these antibodies were DSA after transplant. Preformed DSA and elevated peak PRA were independent predictors of pathologic AMR, which occurred in 19 individuals (7%). The increasing number of DSA and the cumulative mean fluorescence intensity of DSA were associated with AMR. C1q-binding assay was a suboptimal predictor of AMR in our cohort. Pretransplant allosensitization and MICA antibodies were related neither to impaired graft survival nor to other adverse clinical events during a median follow-up of 39 months. Identification of preformed DSA by SPA, in addition to PRA monitoring, may predict AMR in the contemporary era of heart transplantation. PMID:26340387

  10. 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.

  11. Improvement of pesticide adsorption capacity of cellulose fibre by high-energy irradiation-initiated grafting of glycidyl methacrylate

    NASA Astrophysics Data System (ADS)

    Takács, Erzsébet; Wojnárovits, László; Koczog Horváth, Éva; Fekete, Tamás; Borsa, Judit

    2012-09-01

    Cellulose as a renewable raw material was used for preparation of adsorbent of organic impurities in wastewater treatment. Hydrophobic surface of cellulose substrate was developed by grafting glycidyl methacrylate in simultaneous grafting using gamma irradiation initiation. Water uptake of cellulose significantly decreased while adsorption of phenol and a pesticide molecule (2,4-dichlorophenoxyacetic acid: 2,4-D) increased upon grafting. Adsorption equilibrium data fitted the Freundlich isotherm for both solutes.

  12. Preparation and properties of a biomaterial: HEMA grafted SBS by gamma-ray irradiation.

    PubMed

    Hsiue, G H; Yang, J M; Wu, R L

    1988-05-01

    Solvent-cast films of styrene-butadiene-styrene triblock copolymer (SBS) were synthesized and a poly(2-hydroxyethyl methacrylate) (PHEMA) layer was grafted onto these films using Co 60 gamma-ray irradiation. The IR absorption spectrum of the graft copolymer was taken and its surface morphology studied by a scanning electron microscope. The degree of grafting and the mechanical properties of SBS, SBS-g-HEMA, and PHEMA were measured. In order to study its biocompatibility, contact angle and blood clotting time experiments were performed. The degree of grafting was related to the soaking time, film thickness and total irradiation dosage. However, it levelled off at 7% when the total dosage reached 1 Mrad. It was found that the mechanical properties of SBS-g-HEMA were the same as those of SBS and were superior to those of PHEMA. The blood compatibility of SBS-g-HEMA as measured by the Lee-White clotting test was better than that of SBS and polystyrene and was quite similar to that of PHEMA. PMID:3397379

  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. In vitro allograft irradiation prevents graft-versus-host disease in small-bowel transplantation

    SciTech Connect

    Lee, K.K.; Schraut, W.H.

    1985-04-01

    In small-bowel transplantation, the transfer of large numbers of donor lymphocytes with the intestinal allograft may provoke a lethal graft-versus-host reaction. The effectiveness of allograft irradiation in vitro as a method of preventing graft-versus-host disease (GVHD) was studied in a rat model of small-bowel transplantation, with the Lewis----Lewis X Brown Norway F1 hybrid strain combination. Cold harvested small-bowel allografts were irradiated immediately prior to heterotopic or orthotopic transplantation. Animals that had received heterotopic allografts irradiated with 0, 250, or 500 rad all died of GVHD after 14.4 +/- 3.0, 15.0 +/- 1.3, and 14.2 +/- 1.9 days, respectively. None of the animals that had received allografts treated with 1000 rad developed clinical or pathologic evidence of GVHD, however, and all survived for more than 6 months (P less than 0.001). Allograft function was studied in animals that underwent orthotopic transplantation. Recipients of nonirradiated orthotopic allografts all died of GVHD after 14.0 +/- 0.7 days, whereas recipients of allografts irradiated with 1000 rad all survived for more than 5 months (P less than 0.001). After 120 days, weight gain (51.8 +/- 11.7%), serum albumin (3.9 +/- 0.7 g/dl), serum triglycerides (67.0 +/- 24.3 mg/dl), CBC, and differential in these animals were not statistically different from those in either age-matched isograft recipients or normal animals, and when the rats were sacrificed, irradiated allografts showed no changes suggestive of radiation injury. These results indicate that irradiation of small-bowel allografts in vitro prevents development of GVHD, and that this can be achieved at a dose which does not cause injury to or malfunction of the allograft.

  15. 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.

  16. 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

  17. [gamma]-Irradiation-induced grafting of poly(styrenesulfonate) to poly(tetrafluoroethylene) shielded microelectrodes

    SciTech Connect

    Ramos, B.L.; Blubaugh, E.A.; Ridgway, T.H.; Heineman, W.R. )

    1994-06-01

    A new method for the fabrication and polymer modification of microelectrodes is described. These electrodes are constructed by heat sealing the electroactive material in dual shrink/melt poly(tetrafluoroethylene) (PTFE) under vacuum. The PTFE shield may be activated to provide a support upon which polymers of interest may be grafted. [gamma]-Irradiation was used to graft polymerize styrene to the surface. The poly-(styrene) was subsequently sulfonated with chlorosulfonic acid to form poly(styrenesulfonate). Scanning electron microscopy and Raman microspectroscopy provide evidence that the poly-(styrenesulfonate) film has been formed and extends over the electrode material. Voltammetry indicates that hexaammine-ruthenium(III) cation is preconcentrated and stabilized via an association with the polymer film. 24 refs., 8 figs., 2 tabs.

  18. 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. PMID:26858758

  19. 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

  20. 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

  1. 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.

  2. 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...

  3. Impact of Pre-Transplant Anti-T Cell Globulin (ATG) on Immune Recovery after Myeloablative Allogeneic Peripheral Blood Stem Cell Transplantation

    PubMed Central

    Servais, Sophie; Menten-Dedoyart, Catherine; Beguin, Yves; Seidel, Laurence; Gothot, André; Daulne, Coline; Willems, Evelyne; Delens, Loïc; Humblet-Baron, Stéphanie; Hannon, Muriel; Baron, Frédéric

    2015-01-01

    Background Pre-transplant infusion of rabbit anti-T cell globulin (ATG) is increasingly used as prevention of graft-versus-host disease (GVHD) after allogeneic peripheral blood stem cell transplantation (PBSCT). However, the precise impact of pre-transplant ATG on immune recovery after PBSCT is still poorly documented. Methods In the current study, we compared immune recovery after myeloablative PBSCT in 65 patients who either received (n = 37) or did not (n = 28) pre-transplant ATG-Fresenius (ATG-F). Detailed phenotypes of circulating T, B, natural killer (NK) and invariant NKT (iNKT) cells were analyzed by multicolor flow cytometry at serial time-points from day 40 to day 365 after transplantation. Thymic function was also assessed by sjTREC quantification. Serious infectious events were collected up to 2 years post-transplantation. Results Pre-transplant ATG-F had a prolonged (for at least up to 1-year) and selective negative impact on the T-cell pool, while it did not impair the recovery of B, NK nor iNKT cells. Among T cells, ATG-F selectively compromised the recovery of naïve CD4+, central memory CD4+ and naïve CD8+ cells, while it spared effector memory T and regulatory T cells. Levels of sjTRECs were similar in both cohorts at 1-year after PBSCT, suggesting that ATG-F unlikely impaired thymopoiesis at long-term after PBSCT. Finally, the incidence and rate of serious infections were similar in both groups, while ATG-F patients had a lower incidence of grade II-IV acute graft-versus-host disease. Conclusions Pre-transplant ATG-F induces long-lasting modulation of the circulating T-cell pool after myeloablative PBSCT, that may participate in preventing graft-versus-host disease without deeply compromising anti-pathogen defenses. PMID:26098781

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Grafting of synthetic polyelectrolyte onto polymer surfaces--comparison of glow discharge and sup 60 Co-gamma-irradiation method

    SciTech Connect

    Hari, P.R.; Sharma, C.P. )

    1990-07-01

    Water soluble polyelectrolyte synthesized from natural rubber contains sulfamate and carboxylate groups similar to that of heparin. It is observed that synthetic heparinoid polyelectrolyte is capable of inhibiting blood coagulation. In the present study, we attempted to graft the same onto polystyrene and polymethylmethacrylate surfaces using glow discharge technique and {sup 60}Co-gamma-irradiation method, and the surfaces were compared with respect to water contact angle and platelet adhesion parameters. Heparinized surfaces are also evaluated for relative comparison.

  9. 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

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

    PubMed

    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

    2014-10-01

    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

  11. Effect of UV-irradiation intensity on graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on orthopedic bearing substrate.

    PubMed

    Kyomoto, Masayuki; Moro, Toru; Yamane, Shihori; Hashimoto, Masami; Takatori, Yoshio; Ishihara, Kazuhiko

    2014-09-01

    Photoinduced grafting of 2-methacryloyloxyethyl phosphorylcholine (MPC) onto cross-linked polyethylene (CLPE) was investigated for its ability to reduce the wear of orthopedic bearings. We investigated the effect of UV-irradiation intensity on the extent of poly(MPC) (PMPC) grafting, and found that it increased with increasing intensity up to 7.5 mW/cm(2), and the remained fairly constant. It was found to be extremely important to carefully control the UV intensity, as at higher values, a PMPC gel formed via homopolymerization of the MPC, resulting in the formation of cracks at the interface of the PMPC layer and the CLPE substrate. When the CLPE was exposed to UV-irradiation during the graft polymerization process, some of its physical and mechanical properties were slightly changed due to cross-linking and scission effects in the surface region; however, the results of all of the tests exceed the lower limits of the ASTM standards. Modification of the CLPE surface with the hydrophilic PMPC layer increased lubrication to levels that match articular cartilage. The highly hydrated thin PMPC films mimicked the native cartilage extracellular matrix that covers synovial joint surface, acting as an extremely efficient lubricant, and providing high-wear resistance. PMID:24124003

  12. 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.

  13. 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

  14. 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.

  15. The pre-transplant anemic condition is independent of long-term outcome in living-related kidney transplantation.

    PubMed

    Song, Turun; Wang, Li; He, Shaofeng; Fu, Lei; Huang, Zhongli; Wei, Qiang; Lin, Tao

    2014-06-01

    The relationship between pre-transplant Hemoglobin (Hb) concentration and long-term outcome of living-related kidney transplantation is far from well addressed. A retrospective cohort study was conducted by reviewing the medical profile of the patients who received living-related kidney transplantations at our center from January 2006 to January 2013. Patients were divided into two groups: high Hb group (≥10 g/dL) and low Hb group (<10 g/dL). Cox regression model was utilized to analyze the effect of pre-transplant hemoglobin concentration on the patient and graft survival. About 422 patients were of Hb level <10 g/dL (78.30 ± 14.18 g/dL), 280 were >10 g/dL (116.2 ± 14.43 g/dL) (p < 0.001). In a follow-up of 35.34 ± 18.12 months, we did not find any difference in serum creatinine between the two groups. Low Hb concentration is not associated with increased risk of developing DGF (HR = 1.186, 95% CI: 0.53-2.654), acute rejection (HR = 1.338, 95% CI: 0.919-1.947), overall infection (HR = 1.263, 95% CI: 0.847-1.885) nor perioperational infection (HR = 1.019, 95% CI: 0.513-2.026). Though we detected a trend that low Hb level group were of higher incidence of patient death and graft failure, the two groups did not differ significantly (2.38% vs. 0.71%, p = 0.096; and 4.04% vs. 2.14%, p = 0.165, respectively). Cox regression model revealed that pre-transplant Hb level <10 g/dL was independent of increased overall mortality (HR = 3.379; 95% CI: 0.706-17.172) and increased death censored allograft failure risk (HR = 1.556; 95% CI: 0.595-4.069). Pre-transplant Hb concentration <10 g/dL is independent of poor long-term outcome of living-related kidney transplantation. PMID:24512314

  16. Posttransplantation cyclophosphamide for prevention of graft-versus-host disease after HLA-matched mobilized blood cell transplantation.

    PubMed

    Mielcarek, Marco; Furlong, Terry; O'Donnell, Paul V; Storer, Barry E; McCune, Jeannine S; Storb, Rainer; Carpenter, Paul A; Flowers, Mary E D; Appelbaum, Frederick R; Martin, Paul J

    2016-03-17

    The cumulative incidence of National Institutes of Health (NIH)-defined chronic graft-versus-host disease (GVHD) requiring systemic treatment is ∼35% at 1 year after transplantation of granulocyte colony-stimulating factor (G-CSF)-mobilized blood cells from HLA-matched related or unrelated donors. We hypothesized that high-dose cyclophosphamide given after G-CSF-mobilized blood cell transplantation would reduce the cumulative 1-year incidence of chronic GVHD to 15% or less. Forty-three patients with high-risk hematologic malignancies (median age, 43 years) were enrolled between December 2011 and September 2013. Twelve (28%) received grafts from related donors, and 31 (72%) received grafts from unrelated donors. Pretransplant conditioning consisted of fludarabine and targeted busulfan (n = 25) or total body irradiation (≥12 Gy; n = 18). Cyclophosphamide was given at 50 mg/kg per day on days 3 and 4 after transplantation, followed by cyclosporine starting on day 5. The cumulative 1-year incidence of NIH-defined chronic GVHD was 16% (95% confidence interval, 5-28%). The cumulative incidence estimates of grades 2-4 and 3-4 acute GVHD were 77% and 0%, respectively. At 2 years, the cumulative incidence estimates of nonrelapse mortality and recurrent malignancy were 14% and 17%, respectively, and overall survival was projected at 70%. Of the 42 patients followed for ≥1 year, 21 (50%) were relapse-free and alive without systemic immunosuppression at 1 year after transplantation. Thus, myeloablative pretransplant conditioning can be safely combined with high-dose cyclophosphamide after transplantation, and the risk of chronic GVHD associated with HLA-matched mobilized blood cell grafts can be substantially reduced. This trial was registered at www.clinicaltrials.gov as #NCT01427881. PMID:26764356

  17. A mild method of amine-type adsorbents syntheses with emulsion graft polymerization of glycidyl methacrylate on polyethylene non-woven fabric by pre-irradiation

    NASA Astrophysics Data System (ADS)

    Ma, Hongjuan; Yao, Side; Li, Jingye; Cao, Changqing; Wang, Min

    2012-09-01

    A mild pre-irradiation method was used to graft glycidyl methacrylate (GMA) onto polyethylene (PE) non-woven fabric (NF). The polymer was irradiated by electron beam in air atmosphere at room temperature. The degree of grafting (Dg) was determined as a function of reaction time, absorbed dose, monomer concentration and temperature. After 30 kGy irradiation, with 5% GMA, surfactant Tween 20 (Tw-20) of 0.5% at 55 °C for 15 min, the trunk polymer was made grafted with a Dg of 150%. Selected PE-g-PGMA of different Dg was modified with aminated compounds such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA). The obtained amine-type adsorbents were prepared to remove copper and uranium ions from solution. It was shown that at least 90% of copper and 60% of uranium with the initial concentration from 3 to 1000 ppb can be removed from water.

  18. Outcomes of skin graft reconstructions with the use of Vacuum Assisted Closure (VAC®) dressing for irradiated extremity sarcoma defects

    PubMed Central

    Senchenkov, Alex; Petty, Paul M; Knoetgen, James; Moran, Steven L; Johnson, Craig H; Clay, Ricky P

    2007-01-01

    Background Flaps are currently the predominant method of reconstruction for irradiated wounds. The usefulness of split-thickness skin grafts (STSG) in this setting remains controversial. The purpose of this study is to examine the outcomes of STSGs in conjunction with VAC therapy used in the treatment of irradiated extremity wounds. Methods The records of 17 preoperatively radiated patients with extremity sarcomas reconstructed with STSGs in conjunction with VAC® therapy were reviewed regarding details of radiation treatment, wound closure, and outcomes. Results STSGs healed without complications (>95% of the graft take) in 12 (71%). Minor loss (6% – 20% surface) was noted in 3 patients (17.6%) and complete loss in 2 (11.7%). Two patients (11.7%) required flap reconstructions and 12 (88%) healed without further operative procedures. Conclusion Although flap coverage is an established treatment for radiated wounds, STSG in conjunction with liberal utilization of VAC therapy is an alternative for selected patients where acceptable soft tissue bed is preserved. Healing of the preoperatively radiated wounds can be achieved in the vast majority of such patients with minimal need for additional reconstructive operations. PMID:18047659

  19. Pre-Transplant Screening for Latent Adenovirus in Donors and Recipients

    PubMed Central

    Piatti, Gabriella

    2016-01-01

    Human adenoviruses are frequent cause of slight self-limiting infections in immune competent subjects, while causing life-threatening and disseminated diseases in immunocompromised patients, particularly in the subjects affected by acquired immunodeficiency syndrome and in bone marrow and organ transplant recipients. Here, infections interest lungs, liver, encephalon, heart, kidney and gastro enteric tract. To date, human adenoviruses comprise 51 serotypes grouped into seven species, among which species C especially possesses the capability to persist in infected tissues. From numerous works, it emerges that in the recipient, because of loss of immune-competence, both primary infection, via the graft or from the environment, and reactivated endogenous viruses can be responsible for transplantation related adenovirus disease. The transplants management should include the evaluation of anti-adenovirus pre-transplant screening similar to that concerning cytomegalovirus. The serological screening on cytomegalovirus immunity is currently performed to prevent viral reactivation from grafts and recipient, the viral spread and dissemination to different organs and apparatus, and potentially lethal outcome. PMID:27006724

  20. 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

  1. 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.

  2. Kinetics of a methyl methacrylate polymerization initiated by the stable free radicals in irradiated polytetrafluoroethylene and properties of the resultant graft polymer

    SciTech Connect

    Donato, K.A.E.

    1987-01-01

    The kinetics of the polymerization of methyl methacrylate (MMA) initiated by the stable free radicals in commercially available irradiated polytetrafluoroethylene micropowder and the rheological, thermal, chemical, and mechanical properties of the resultant graft polymer are described. Test tube runs using different ratios of MMA to PTFE were made to determine the feasibility of the reaction and optimum reaction conditions. The amount of graft produced was equal to the weight gain of the solids after removal of the adventitious homopolymer by extraction in acetone. Test quantities of material were produced in a 500 milliliter agitated reactor. A higher ratio of PTFE to excess MMA and longer reaction times result in higher conversion in test tubes. A kinetic model was developed to relate the original concentration of PTFE free radical to the amount of MMA polymer. Graft polymer containing PTFE micropowder, PMMA graft, and PMMA homopolymer in a ratio of 18:5:1 was used for property characterization. The graft material extrudes well at 513K and has a viscosity comparable to that of PMMA homopolymer. The material is stable upon re-extrusion. DSC thermograms show that the heat of transition of the PTFE melting peak is proportional to the amount of PTFE in the sample. Good solvents for PMMA are detrimental to the structural integrity of the graft extrudate; heat treatment improves the chemical resistance. The PTFE block controls the mechanical properties of the graft.

  3. 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.

  4. Repair of surgical bone defects grafted with hydroxylapatite + β-TCP and irradiated with λ=850 nm LED light.

    PubMed

    Soares, Luiz Guilherme P; Marques, Aparecida Maria C; Guarda, Milena G; Aciole, Jouber Mateus S; Pinheiro, Antonio Luiz B; dos Santos, Jean Nunes

    2015-01-01

    The treatment of bone loss due to different etiologic factors is difficult and many techniques aim to improve the repair, including a wide range of biomaterials and recently, photobioengineering. This work aimed to assess by histological analysis the repair of bone defects grafted with biphasic synthetic micro-granular HA + β-TCP associated with LED phototherapy. Forty rats were divided into 4 groups (Clot, LED, Biomaterial and LED + Biomaterial) each subdivided into 2 subgroups according to the time of animal death (15 and 30 days). Surgical bone defects were prepared on the femur of each animal with a trephine drill. In animals of the Clot group the defect was filled only by blood clot, in the LED group the defect filled with the clot was further irradiated. In the animals of Biomaterial and LED + Biomaterial groups the defect was filled by biomaterial and the last one was further irradiated (λ = 850 ± 10 nm, 150 mW, Φ ~ 0.5 cm2, 20 J/cm2 - session, 140 J/cm2- treatment) at 48-h intervals for 2 weeks. Following animal death, samples were taken and analyzed by light microscopy. Using the degree of maturation of the bone by assessment of the deposition/organization of the basophilic lines in the newly formed bone tissue, the LED + Biomaterial group was the one in a more advanced stage of bone repair process at the end of the experiment. It may be concluded that the use of LED phototherapy was effective in positively modulating the process of bone repair of bone defects in the femur of rats submitted or not to biomaterial grafting. PMID:25672379

  5. 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. PMID:23621025

  6. 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.

  7. 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.

  8. 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.

  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. 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. PMID:25101080

  11. Pretransplant Hepatitis B Viral Infection Increases Risk of Death After Kidney Transplantation

    PubMed Central

    Lee, Jeonghwan; Cho, Jang-Hee; Lee, Jong Soo; Ahn, Dong-Won; Kim, Chan-Duck; Ahn, Curie; Jung, In Mok; Han, Duck Jong; Lim, Chun Soo; Kim, Yon Su; Kim, Young Hoon; Lee, Jung Pyo

    2016-01-01

    Abstract Clinical outcomes in kidney transplant recipients (KTRs) with hepatitis B virus (HBV) have not been thoroughly evaluated. Here, we investigated recent posttransplant clinical outcomes of KTRs with HBV and compared them with KTRs with hepatitis C virus (HCV) and seronegative KTRs. Of 3855 KTRs from April 1999 to December 2011, we enrolled 3482 KTRs who had viral hepatitis serology data; the patients were followed up for 89.1 ± 54.1 months. The numbers of recipients with HBV and HCV were 160 (4.6%) and 55 (1.6%), respectively. We analyzed the clinical outcomes, including overall mortality and graft failure, among patients who had undergone kidney transplantation. Patients with HBV showed poorer survival (P = 0.019; adjusted hazard ratio [HR] = 2.370; 95% confidence interval [CI]: 1.155–4.865) than KTRs without HBV. However, the graft survival of patients with chronic hepatitis B did not differ from that of patients without HBV. Hepatic complications were the primary causes of mortality of KTRs with HBV. Mortality significantly correlated with a higher grade of inflammation (P = 0.002) and with the use of lamivudine or adefovir antiviral treatment (P = 0.016). HBV-positive KTRs treated with the new-generation antiviral agent entecavir showed improved patient survival compared with KTRs receiving lamivudine (log-rank P = 0.050). HCV did not affect patient survival; however, it increased the incidence of graft failure (P = 0.010; adjusted HR = 2.899; 95% CI: 1.289–6.519). KTRs with HCV had an increased incidence of acute rejection (log-rank P = 0.005, crude HR = 2.144; 95% CI: 1.341–3.426; P = 0.001). KTRs with chronic hepatitis B may exhibit poor survival due to post-transplantation hepatic complications. Pretransplant histological liver evaluations and adequate antiviral management with potent nucleoside/nucleotide analogues are needed to improve the survival of KTRs with chronic hepatitis B even when liver

  12. Skin graft

    MedlinePlus

    Skin transplant; Skin autografting; FTSG; STSG; Split thickness skin graft; Full thickness skin graft ... site. Most people who are having a skin graft have a split-thickness skin graft. This takes ...

  13. 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. PMID:23762345

  14. 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

  15. 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

  16. 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

  17. Pretransplant renal dysfunction predicts poorer outcome in liver transplantation.

    PubMed

    Lafayette, R A; Paré, G; Schmid, C H; King, A J; Rohrer, R J; Nasraway, S A

    1997-09-01

    The postoperative courses of 115 liver transplant recipients were reviewed to monitor for outcomes of acute renal failure and mortality. An analysis of baseline (preoperative) variables with particular attention to baseline renal function was accomplished to establish predictive variables for a complicated postoperative course. Acute renal failure requiring dialysis occurred in 27 cases (23%) and was associated with a prolonged ICU stay, greater infectious complications, greater hospital charges and a high mortality rate (46 +/- 11% vs. 9 +/- 3%) as compared to patients who did not experience acute renal failure. Death occurred in 20 patients (17%) overall prior to discharge. In order to assess the contribution of renal function, the population was divided arbitrarily into two groups based on preoperative serum creatinine. Group 1 (n = 50) had a preoperative serum creatinine < 1.0 mg/dl (mean +/- SD = 2.2 +/- 0.2 mg/dl) and Group 2 (n = 65) had a preoperative serum creatinine < or = 1.0 mg/dl (0.7 +/- 0.1 mg/dl). The groups experienced similar operative courses. Group 1 patients experienced significantly longer ICU stays (18 +/- 3 vs. 10 +/- 2 days), higher rates of acute renal failure requiring dialysis (52 +/- 7 vs. 5 +/- 2%), higher hospital charges (231,454 +/- 17,088 vs. 178,755 +/- 14,744 $, US) and a greatly increased mortality rate (32 +/- 1 vs. 6 +/- 1%), as compared to Group 2 patients. A multifactorial regression analysis demonstrated that of all pretransplant factors analyzed, elevation in the serum creatinine was significantly associated and was the strongest predictor of both outcomes: acute renal failure requiring dialysis (ROC = 0.89) and death (ROC = 0.83). The presence or absence of hepatorenal syndrome did not influence the results of this analysis. This study demonstrates that cirrhotic patients with renal dysfunction, as indicated by an elevated serum creatinine, experience a poor surgical outcome following liver transplantation. These patients

  18. Bone Grafts

    MedlinePlus

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some ...

  19. 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

  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. Pretransplant CD4 Count Influences Immune Reconstitution and Risk of Infectious Complications in Human Immunodeficiency Virus-Infected Kidney Allograft Recipients.

    PubMed

    Suarez, J F; Rosa, R; Lorio, M A; Morris, M I; Abbo, L M; Simkins, J; Guerra, G; Roth, D; Kupin, W L; Mattiazzi, A; Ciancio, G; Chen, L J; Burke, G W; Goldstein, M J; Ruiz, P; Camargo, J F

    2016-08-01

    In current practice, human immunodeficiency virus-infected (HIV(+) ) candidates with CD4 >200 cells/mm(3) are eligible for kidney transplantation; however, the optimal pretransplant CD4 count above this threshold remains to be defined. We evaluated clinical outcomes in patients with baseline CD4 >350 and <350 cells/mm(3) among 38 anti-thymocyte globulin (ATG)-treated HIV-negative to HIV(+) kidney transplants performed at our center between 2006 and 2013. Median follow-up was 2.6 years. Rates of acute rejection and patient and graft survival were not different between groups. Occurrence of severe CD4 lymphopenia (<200 cells/mm(3) ), however, was more common among patients with a baseline CD4 count 200-349 cells/mm(3) compared with those transplanted at higher counts (75% vs. 30% at 4 weeks [p = 0.04] and 71% vs. 5% at 52 weeks [p = 0.001], respectively, after transplant). After adjusting for age, baseline CD4 count of 200-349 cells/mm(3) was an independent predictor of severe CD4 lymphopenia at 4 weeks (relative risk [RR] 2.6; 95% confidence interval [CI] 1.3-5.1) and 52 weeks (RR 14.3; 95% CI 2-100.4) after transplant. Patients with CD4 <200 cells/mm(3) at 4 weeks had higher probability of serious infections during first 6 months after transplant (19% vs. 50%; log-rank p = 0.05). These findings suggest that ATG must be used with caution in HIV(+) kidney allograft recipients with a pretransplant CD4 count <350 cells/mm(3) . PMID:26953224

  3. 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.

  4. Clofarabine ± fludarabine with once daily i.v. busulfan as pretransplant conditioning therapy for advanced myeloid leukemia and MDS.

    PubMed

    Andersson, Borje S; Valdez, Benigno C; de Lima, Marcos; Wang, Xuemei; Thall, Peter F; Worth, Laura L; Popat, Uday; Madden, Timothy; Hosing, Chitra; Alousi, Amin; Rondon, Gabriela; Kebriaei, Partow; Shpall, Elizabeth J; Jones, Roy B; Champlin, Richard E

    2011-06-01

    -ATG (Thymoglobulin™). All patients engrafted. Forty-one patients had active leukemia at the time of transplant, and 35 achieved CR (85%). Twenty of the 42 AML patients and 5 of 9 CML patients are alive with a projected median overall survival (OS) of 23 months. Marrow and blood (T cell) chimerism studies at day +100 revealed that both in the lower-dose Clo groups (groups 1+2) and the higher-dose Clo groups (groups 3+4), the patients had a median of 100% donor (T cell)-derived DNA. There has been no secondary graft failure. In the first 100 days, 1 patient died of pneumonia, and 1 of liver GVHD. We conclude that (1) Clo ± Flu with i.v. Bu as pretransplant conditioning is safe in high-risk myeloid leukemia patients; (2) clofarabine is sufficiently immunosuppressive to support allo-SCT in myeloid leukemia; and (3) the median OS of 23 months in this high-risk patient population is encouraging. Additional studies to evaluate the antileukemic efficacy of Clo ± Flu with i.v. Bu as pretransplant conditioning therapy are warranted. PMID:20946966

  5. Determinants of graft survival in pediatric and adolescent live donor kidney transplant recipients: a single center experience.

    PubMed

    El-Husseini, Amr A; Foda, Mohamed A; Shokeir, Ahmed A; Shehab El-Din, Ahmed B; Sobh, Mohamed A; Ghoneim, Mohamed A

    2005-12-01

    To study the independent determinants of graft survival among pediatric and adolescent live donor kidney transplant recipients. Between March 1976 and March 2004, 1600 live donor kidney transplants were carried out in our center. Of them 284 were 20 yr old or younger (mean age 13.1 yr, ranging from 5 to 20 yr). Evaluation of the possible variables that may affect graft survival were carried out using univariate and multivariate analyses. Studied factors included age, gender, relation between donor and recipient, original kidney disease, ABO blood group, pretransplant blood transfusion, human leukocyte antigen (HLA) matching, pretransplant dialysis, height standard deviation score (SDS), pretransplant hypertension, cold ischemia time, number of renal arteries, ureteral anastomosis, time to diuresis, time of transplantation, occurrence of acute tubular necrosis (ATN), primary and secondary immunosuppression, total dose of steroids in the first 3 months, development of acute rejection and post-transplant hypertension. Using univariate analysis, the significant predictors for graft survival were HLA matching, type of primary urinary recontinuity, time to diuresis, ATN, acute rejection and post-transplant hypertension. The multivariate analysis restricted the significance to acute rejection and post-transplant hypertension. The independent determinants of graft survival in live-donor pediatric and adolescent renal transplant recipients are acute rejection and post-transplant hypertension. PMID:16269048

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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

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

    PubMed

    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

  12. Effects of pretransplant plasmapheresis and rituximab on recurrence of focal segmental glomerulosclerosis in adult renal transplant recipients

    PubMed Central

    Park, Hoon Suk; Hong, Yuah; Sun, In O; Chung, Byung Ha; Kim, Hyung Wook; Choi, Bum Soon; Park, Cheol Whee; Jin, Dong Chan; Kim, Yong Soo

    2014-01-01

    Background/Aims Recurrent focal segmental glomerulosclerosis (FSGS) following renal transplantation is relatively common. However, the risk factors and optimal pretransplant treatment preventing recurrence of FSGS remain controversial. Methods We retrospectively reviewed 27 adult renal transplant recipients with FSGS over a period of 10 years. We first compared possible risk factors for FSGS recurrence between the recurrence and nonrecurrence groups. Then we evaluated the effect of pretransplant plasmapheresis (PP; n = 4) and PP with rituximab (PP + RTX; n = 5) on recurrence of FSGS after transplantation compared to control patients that were not treated with these modalities. Results There were seven recurrences in 27 patients (25.9%), but there were no significant differences in possible risk factors for FSGS recurrence between the two groups. Recurrence rates between patients with pretransplant PP or PP + RTX and control patients were not significantly different (22.2% vs. 27.7%, p > 0.05). There was also no significant difference in recurrence between the pretransplant PP and PP + RTX groups (25% vs. 20%, p > 0.05). Conclusions Pretransplant PP or PP + RTX do not significantly decrease the recurrence of FSGS in adult renal transplant candidates. PMID:25045296

  13. Pretransplant thymic function predicts acute rejection in antithymocyte globulin-treated renal transplant recipients.

    PubMed

    Bamoulid, Jamal; Courivaud, Cécile; Crepin, Thomas; Carron, Clémence; Gaiffe, Emilie; Roubiou, Caroline; Laheurte, Caroline; Moulin, Bruno; Frimat, Luc; Rieu, Philippe; Mousson, Christiane; Durrbach, Antoine; Heng, Anne-Elisabeth; Rebibou, Jean-Michel; Saas, Philippe; Ducloux, Didier

    2016-05-01

    Lack of clear identification of patients at high risk of acute rejection hampers the ability to individualize immunosuppressive therapy. Here we studied whether thymic function may predict acute rejection in antithymocyte globulin (ATG)-treated renal transplant recipients in 482 patients prospectively studied during the first year post-transplant of which 86 patients experienced acute rejection. Only CD45RA(+)CD31(+)CD4(+) T cell (recent thymic emigrant [RTE]) frequency (RTE%) was marginally associated with acute rejection in the whole population. This T-cell subset accounts for 26% of CD4(+) T cells. Pretransplant RTE% was significantly associated with acute rejection in ATG-treated patients (hazard ratio, 1.04; 95% confidence interval, 1.01-1.08) for each increased percent in RTE/CD4(+) T cells), but not in anti-CD25 monoclonal (αCD25 mAb)-treated patients. Acute rejection was significantly more frequent in ATG-treated patients with high pretransplant RTE% (31.2% vs. 16.4%) or absolute number of RTE/mm(3) (31.7 vs. 16.1). This difference was not found in αCD25 monclonal antibody-treated patients. Highest values of both RTE% (>31%, hazard ratio, 2.50; 95% confidence interval, 1.09-5.74) and RTE/mm(3) (>200/mm(3), hazard ratio, 3.71; 95% confidence interval, 1.59-8.70) were predictive of acute rejection in ATG-treated patients but not in patients having received αCD25 monoclonal antibody). Results were confirmed in a retrospective cohort using T-cell receptor excision circle levels as a marker of thymic function. Thus, pretransplant thymic function predicts acute rejection in ATG-treated patients. PMID:27083287

  14. Effects of LED or laser phototherapy on bone defects grafted with MTA and irradiated with laser or LED light: a comparative Raman spectroscopic study

    NASA Astrophysics Data System (ADS)

    Pinheiro, Antonio L. B.; Soares, Luiz G. P.; Barbosa, Artur Felipe S.; Silveira, Landulfo, Jr.

    2012-03-01

    We studied peaks of calcium hydroxyapatite - CHA on defects grafted with MTA, treated or not with Light Emitting Diode - LED or IR Laser. 54 rats were divided in 6 groups each subdivided into 3 subgroups (15,21,30d). LED (λ850 +/- 10nm) or IR Laser (λ850 nm) was applied over (LED) or in 4 points around the defect at 48 h intervals for 15 days. Raman readings were taken at the surface of the defect. The smaller overall intensity of the peak was found in Group MTA + Laser (1510.2 +/- 274.1) and the highest on Group LED (2322 +/- 715). There were no statistically significant differences between non-irradiated subjects on regards the CHA peaks. On the other hand, there were statistically significant differences between the Group Clot and LED, Clot and Laser, and Clot and MTA + Laser (p =0.01, p = 0.02, p = 0.003). There were no significant differences between Group MTA and MTA + LED (p=0.2) but significant differences were seen between Groups MTA and MTA + Laser (p=0.01). Significant differences were also observed between Groups LED and Laser (p <0.001) and between Groups MTA + LED and MTA + Laser (p=0.009). MTA, due to its characteristics, seemed to be directly affected by the light. However, the use of either phototherapy positively affected bone healing similarly as observed on different studies using other biomaterials. The overall analysis of our results indicated that the use of either light source resulted in a better, more advanced, and of quality bone repair.

  15. The clinical and molecular epidemiology of pre-transplant vancomycin-resistant enterococci colonization among liver transplant recipients.

    PubMed

    Banach, David B; Peaper, David R; Fortune, Brett E; Emre, Sukru; Dembry, Louise M

    2016-03-01

    Vancomycin-resistant enterococci (VRE) infections cause significant morbidity in liver transplant recipients. The epidemiology and impact of pre-transplant colonization with VRE among patients who undergo liver transplantation are poorly understood. We conducted an observational cohort study to identify risk factors and outcomes associated with pre-transplant VRE colonization and described the molecular diversity among VRE strains colonizing patients who undergo liver transplantation. Perirectal VRE surveillance cultures were performed prior to transplantation. Repetitive sequence-based polymerase chain reaction (rep-PCR) testing was used to identify clonality among VRE isolates. Of 61 patients who underwent pre-transplant VRE surveillance and subsequent liver transplantation, 27 (44%) were colonized with VRE. In multivariate analysis, pre-transplant VRE colonization was associated with central venous catheterization (OR 9.4, 95% confidence interval [CI]= 1.3-70.2, p = 0.03) and rifaximin use (OR 15.4, 95% CI 1.5-159.7, p = 0.02). Pre-transplant VRE colonization was associated with more hospital days post-transplant (26.6 vs. 16.1 d, p = 0.04). Of VRE-colonized patients analyzed with rep-PCR, 68% were colonized with the same strain as another patient in the cohort. Active surveillance identifies VRE-colonized patients who may benefit from targeted antimicrobial prophylaxis and enhanced infection prevention measures to prevent VRE spread. The relationship between rifaximin receipt and VRE colonization warrants further study. The identification of similar VRE isolates may suggest linked transmission during pre-transplant hospitalizations, which should be further investigated in prospective studies. PMID:26780305

  16. Upgrading pretransplant human islet culture technology requires human serum combined with media renewal.

    PubMed

    Kerr-Conte, Julie; Vandewalle, Brigitte; Moerman, Ericka; Lukowiak, Bruno; Gmyr, Valery; Arnalsteen, Laurent; Caiazzo, Robert; Sterkers, Adrien; Hubert, Thomas; Vantyghem, Marie Christine; Pattou, François

    2010-05-15

    BACKGROUND.: The original Edmonton protocol used fresh islets, but for obvious logistic advantages most transplant centers have implemented pretransplant culture in human albumin. The aim of this study was to improve current pretransplant human islet culture techniques. METHODS.: Clinical-grade purified human islets from a total of 24 donors were directly resuspended after isolation in CMRL 1066-based media at 37 degrees C, and media additions and renewal were tested. At days 1 and 5 of culture, in vitro quality controls included islet viability, insulin content and function, apoptosis, and in vivo islet potency assay in nude mice. RESULTS.: Replacing human albumin with human AB serum improved 1- and 5-day preservation of islet function and viability which was further enhanced with antioxidant Stem Ease, leading to the iCulture medium (enriched CMRL: pyruvate, zinc sulfate, insulin, transferrin, selenium, 2.5% human AB serum and Stem Ease). Major damage occurs in the first day of culture and frequent media renewal (25% vol/hr) in this period further improved viability, apoptosis, islet recovery, and function in vitro and in vivo, compared with only changing medium after overnight culture. CONCLUSIONS.: The described human islet culture technique (iCulture medium+renewal) seems to be the best choice for clinical human islet culture when short (1 day) or long (5 days) periods are used. Media choice and dilution play a major role in the function and survival of human islets in culture. PMID:20098354

  17. Pretransplant immediately early-1-specific T cell responses provide protection for CMV infection after kidney transplantation.

    PubMed

    Bestard, O; Lucia, M; Crespo, E; Van Liempt, B; Palacio, D; Melilli, E; Torras, J; Llaudó, I; Cerezo, G; Taco, O; Gil-Vernet, S; Grinyó, J M; Cruzado, J M

    2013-07-01

    Cytomegalovirus (CMV) infection is still a major complication after kidney transplantation. Although cytotoxic CMV-specific T cells play a crucial role controlling CMV survival and replication, current pretransplant risk assessment for CMV infection is only based on donor/recipient (IgG)-serostatus. Here, we evaluated the usefulness of monitoring pre- and 6-month CMV-specific T cell responses against two dominant CMV antigens (IE-1 and pp65) and a CMV lysate, using an IFN-γ Elispot, for predicting the advent of CMV infection in two cohorts of 137 kidney transplant recipients either receiving routine prophylaxis (n = 39) or preemptive treatment (n = 98). Incidence of CMV antigenemia/disease within the prophylaxis and preemptive group was 28%/20% and 22%/12%, respectively. Patients developing CMV infection showed significantly lower anti-IE-1-specific T cell responses than those that did not in both groups (p < 0.05). In a ROC curve analysis, low pretransplant anti-IE-1-specific T cell responses predicted the risk of both primary and late-onset CMV infection with high sensitivity and specificity (AUC > 0.70). Furthermore, when using most sensitive and specific Elispot cut-off values, a higher than 80% and 90% sensitivity and negative predictive value was obtained, respectively. Monitoring IE-1-specific T cell responses before transplantation may be useful for predicting posttransplant risk of CMV infection, thus potentially guiding decision-making regarding CMV preventive treatment. PMID:23711167

  18. 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

  19. Bone Grafts

    MedlinePlus

    ... repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some types of fractures or cancers. Once your body accepts the bone ...

  20. Impact of pretransplant rifaximin therapy on early post-liver transplant infections.

    PubMed

    Esfeh, Jamak Modaresi; Hanouneh, Ibrahim A; Koval, Christine E; Kovacs, Christopher; Dalal, Deepan S; Ansari-Gilani, Kianoush; Confer, Bradley D; Eghtesad, Bijan; Zein, Nizar N; Menon, K V Narayanan

    2014-05-01

    Bacterial and fungal infections are major causes of morbidity and mortality after liver transplantation (LT). The role of intestinal decontamination in the prevention of post-LT infections is controversial. Rifaximin is widely used for the treatment of hepatic encephalopathy. The effect of rifaximin on post-LT infections is unknown. The aim of our study was to determine the effect of rifaximin therapy in the pretransplant period on early bacterial infections (EBIs) and fungal infections within the first 30 days after LT. All adult patients who underwent LT at our institution (January 2009 to July 2011) were included in this retrospective cohort study. Patients receiving antibiotics other than pretransplant protocol antibiotics were excluded. Patients were stratified into 2 groups based on the presence or absence of rifaximin therapy for at least 2 days before LT. Infections were defined by the isolation of any bacterial or fungal organisms within 30 days of LT. Multivariate regression analysis, Student t tests, and Pearson's chi-square tests were used to compare the 2 groups. Two hundred sixty-eight patients were included, and 71 of these patients (26.5%) were on rifaximin at the time of LT. The 2 groups were comparable with respect to age, sex, race, and Model for End-Stage Liver Disease score. There were no significant differences in the rates of EBIs (30% for the non-rifaximin group and 25% for the rifaximin group, P = 0.48) or fungal infections between the 2 groups. There was no increase in antimicrobial resistance among the infecting organisms. There was no difference in survival between the rifaximin and non-rifaximin groups (98% versus 97%, P = 0.36). In conclusion, the use of rifaximin in the pre-LT period was not associated with an increased risk of bacterial or fungal infections in the early post-LT period. PMID:24493238

  1. Grafting copolymerization of acrylamides onto preirradiated PP films

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Nho, Young Chang; Kwon, Oh Hyun; Hoffman, Allan S.

    1999-06-01

    Acrylamide (AAm), N,N-Dimethylacrylamide (DMAAm) and N-(3-Dimethylaminopropyl) methacrylamide (DMAPMAAm) were grafted onto polypropylene (PP) films by preirradiation grafting respectively. The effect of irradiation dose, solvent systems and reaction time on the degree of grafting were determined. The grafted sample films were verified by Fourier Transform Infrared (FTIR) spectroscopy in the attenuated total reflectance mode (ATR) and the determination of water contact angle. The blood compatibility of the grafted PP films were evaluated by the determination of platelet adsorption and thrombus. The blood compatibility of grafted PP films seems better than that of original PP films.

  2. Prognostic value of pretransplant serum C-reactive protein in patients receiving reduced-intensity conditioning allogeneic hematopoietic stem cell transplantation.

    PubMed

    Yamamoto, Wataru; Fujii, Eriko; Matsumoto, Kenji; Yamamoto, Eri; Aoki, Jun; Tanaka, Masatsugu; Ishigatsubo, Yoshiaki; Kanamori, Heiwa

    2016-04-01

    The impact of pre-transplant serum C-reactive protein (CRP) level on the outcome of reduced-intensity conditioning allogeneic hematopoietic stem cell transplantation (RIC allo-SCT) is unclear. This study retrospectively investigated 78 patients who underwent RIC allo-SCT between 2005 and 2013. The conditioning regimen consisted of fludarabine and melphalan with/without total body irradiation. The 3-year overall survival of high CRP (43.6 % of all patients) patients was significantly worse than that of normal CRP patients in whom CRP was ≤0.3 mg/dl (26.7 vs. 74.1 %, P < 0.001). Both the CRP level before transplantation and disease risk status were independent prognostic factors for overall survival by multivariate analysis. CRP was not a significant predictor of NRM by multivariate analysis (hazard ratio 3.2, 95 % confidence interval 0.8-13.1, P = 0.100). These results suggest that measuring the CRP level before transplantation can be useful to predicting the outcome of RIC allo-SCT. PMID:26791379

  3. Properties of starch-polyglutamic acid (PGA) graft copolymer prepared by microwave irradiation - the 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. The starch-PGA copolymers absorbed water and formed gels, which exhibited concentration-dependent viscoelastic solid properties. Higher starch-PGA concentrations resulted in stronger viscoelastic p...

  4. Viability of full-thickness skin grafts used for correction of cicatricial ectropion of lower eyelid in previously irradiated field in the periocular region

    PubMed Central

    Kim, Hee Joon; Hayek, Brent; Nasser, Qasiem; Esmaeli, Bita

    2013-01-01

    Purpose To evaluate the viability of skin grafts used for correction of cicatricial ectropion resulting from previous ablative surgery and radiotherapy for head and neck cancer and to report overall outcomes of cicatricial ectropion repair. Methods This is a retrospective, non-comparative case series of all consecutive head and neck cancer patients who had been exposed to high-dose radiation therapy in their periocular region and had surgical correction of their lower eyelid cicatricial ectropion through placement of a full-thickness skin graft and a lower eyelid tightening procedure by the same surgeon. The primary outcome measure was skin graft viability. Secondary outcome measures comprised of post-operative complications, the overall outcome of ectropion repair as judged by improvement in symptoms of exposure keratopathy and dependence on lubricating eye drops and ointments, as well as cosmetic improvement measured through a grading scale determined based on the degree of inferior scleral show and/or tarsal conjunctival eversion. Results 25 patients were eligible for the study. 19 men and 6 women had a median age of 63 years (range: 20–84 years). All 25 patients had high-dose radiation therapy for their head and neck cancer. All but 1 patient had major cancer ablative surgery performed prior to radiation therapy. Thirteen of 25 patients also received chemotherapy. There was 100% viability of the skin grafts used for the repair of lower eyelid cicatricial ectropion. There were a few post-operative complications including the need for revision surgery to correct residual ectropion in the lower eyelid in 2 patients and a third patient required a revision surgery due to upper lid retraction and lagophthalmos after harvest of skin graft from the upper eyelid. Improvement was noted in the subjective symptoms in 22 of 25 patients (88%) while 17 patients (68%) were noted to have improvement in their clinical findings on slit lamp examination. All 20 patients for whom

  5. 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.

  6. 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)

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    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 ΔHf and crystallinity percentage decrease at higher PEgMAH content.

  7. 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

  8. 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

  9. Intellectual and academic performance in children undergoing solid organ pretransplant evaluation.

    PubMed

    Reed-Knight, Bonney; Lee, Jennifer L; Cousins, Laura A; Mee, Laura L

    2015-03-01

    Although prior research has shown lower intellectual functioning across pediatric solid organ transplant recipients relative to matched siblings or norm comparisons, few studies have assessed intellectual and academic performance prior to transplant across organ groups. The current data examine intellectual and academic functioning in children being evaluated for kidney, liver, or heart transplant. This investigation included intellectual and academic testing data from 195 children and adolescents between the ages of six and 19 yr evaluated for solid organ transplantation. Across organ groups, patients' intellectual functioning as estimated by the WASI/WASI-II at the time of pretransplant evaluation was within the average range, but lower compared to test norms. Patients demonstrated lower estimates of word reading, math computation, and spelling skills compared to the normal population, with the exception of heart patients' word reading and spelling skills and liver patients' spelling scores. Cognitive and academic impairments exist in children prior to transplantation. Findings emphasize the support that patients may require to manage the complicated medical regimen and succeed academically. Routine cognitive and academic assessment can inform healthcare providers regarding transplant patients' capacity to take on increasing medical responsibility and successfully reintegrate into the school environment. PMID:25389073

  10. 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

  11. Prognostic Importance of Pretransplant Functional Capacity After Allogeneic Hematopoietic Cell Transplantation

    PubMed Central

    Devlin, Sean M.; Maloy, Molly A.; Wood, William A.; Tuohy, Sharlynn; Espiritu, Noel; Aquino, Jennifer; Kendig, Tiffany; Michalski, Meghan G.; Gyurkocza, Boglarka; Schaffer, Wendy L.; Ali, Benzar; Giralt, Sergio; Jakubowski, Ann A.

    2015-01-01

    Background. The purpose of this study was to investigate the prognostic importance of functional capacity in patients undergoing allogeneic hematopoietic cell transplantation (HCT) for hematological malignancies. Patients and Methods. Using a retrospective design, 407 patients completed a 6-minute walk distance (6MWD) test to assess functional capacity before HCT; 193 (47%) completed a 6MWD test after hospital discharge. Cox proportional hazards regression was used to estimate the risk of nonrelapse mortality (NRM) and overall survival (OS) according to the 6MWD category (<400 m vs. ≥400 m) and the change in 6MWD (before HCT to discharge) with or without adjustment for Karnofsky performance status (KPS), age, and other prognostic markers. Results. Compared with <400 m, the unadjusted hazard ratio for NRM was 0.65 (95% confidence interval, 0.44–0.96) for a 6MWD ≥400 m. A 6MWD of ≥400 m provided incremental information on the prediction of NRM with adjustment for age (p = .032) but not KPS alone (p = .062) or adjustment for other prognostic markers (p = .099). A significant association was found between the 6MWD and OS (p = .027). A 6MWD of ≥400 m provided incremental information on the prediction of OS with adjustment for age (p = .032) but not for other prognostic markers (p > .05 for all). Patients presenting with a pre-HCT 6MWD of <400 m and experiencing a decline in 6MWD had the highest risk of NRM. Conclusion. The 6MWD is a significant univariate predictor of clinical outcomes but did not provide prognostic information beyond that of traditional prognostic markers in HCT. Implications for Practice: The pretransplant 6-minute walk test is a significant univariate predictor of clinical outcomes in hematological patients beyond age but not beyond that of performance status. On this basis, 6-minute walk distance testing should not be considered part of the standard battery of assessments for risk stratification before hematopoietic cell transplantation

  12. Pre-transplant angiotensin receptor II type 1 antibodies and risk of post-transplant focal segmental glomerulosclerosis recurrence.

    PubMed

    Mujtaba, Muhammad A; Sharfuddin, Asif A; Book, Benita L; Goggins, William C; Khalil, Ali A; Mishler, Dennis P; Fridell, Johnathan A; Yaqub, Muhammad S; Taber, Tim E

    2015-07-01

    Post-kidney transplant recurrence of focal segmental glomerulosclerosis (FSGS) is a major problem. AT1R is expressed on podocyte; its expression is elevated in the proteinuric state. Using an ELISA, we tested pre-transplant sera of 28 patients with history of idiopathic FSGS for anti-AT1R levels and serum soluble urokinase-type plasminogen activator receptor (suPAR) as a biomarker for risk of recurrence of FSGS. Sera from 11 patients with polycystic kidney disease (PKD) were used as controls. Twelve patients had biopsy proven post-transplant FSGS recurrence at 1.5 months. No difference was found in the pre-transplant suPAR levels of FSGS patients (5993 ± 2292 pg/mL) vs. PKD (7334 ± 4538 pg/mL) (p = 0.23). Serum suPAR levels in patients with FSGS recurrence (5786 ± 1899 pg/mL) vs. no FSGS recurrence (6149 ± 2598 pg/mL) (p = 0.69) were not different. Anti-AT1R levels in patients with FSGS were 12.66 ± 11.85 U/mL vs. 8.69 ± 6.52 U/mL in PKD (p = 0.32); however, a difference was found in patients with and without FSGS recurrence 20.41 ± 14.36 U/mL 6.84 ± 4.181 U/mL, respectively (p < 0.01). Area under curve for suPAR and anti-AT1R to predict post-transplant FSGS recurrence was 0.51 and 0.84, respectively. Pre-transplant anti-AT1R levels appear to be a helpful biomarker in identifying patients at high risk of post-transplant FSGS recurrence. PMID:25973696

  13. Concerns regarding the financial aspects of kidney transplantation: perspectives of pre-transplant patients and their family members

    PubMed Central

    Ganji, Sumitha; Ephraim, Patti L.; Ameling, Jessica M.; Purnell, Tanjala S.; Lewis-Boyer, LaPricia L.; Boulware, L. Ebony

    2015-01-01

    Background African American and non-African American pre-transplant patients’ and their families’ concerns about the financial costs of kidney transplantation have not been well studied. Methods We conducted structured group interviews among pre-transplant patients (seven African American, five non-African American) and their family members (six African American, five non-African American) to identify their concerns about transplant health insurance coverage, out-of-pocket expenses, and living donor expenses. We reviewed transcribed group audio recordings and identified common discussion themes. Results African American and non-African American patients and family members expressed uncertainty about which transplant-related costs were covered by health insurance and wanted information about how to choose insurance policies accordingly. Patients were particularly concerned about the impact of pre-existing illness on securing optimal health insurance, while family members wanted information about non-insurance-based financial resources. Both patients and family members expressed concern about paying for immunosuppressant medications and about gradual loss of insurance benefits after transplantation. Both patients and family members also expressed concern about potential financial hardships for living donors. Conclusion African American and non-African American pre-transplant patients and families expressed a broad range of concerns about transplant health insurance policies, out-of-pocket expenses, non-insurance-based financial resources, and resources to address donors’ financial burden. Efforts to improve education and develop more comprehensive transplant insurance policies are needed to facilitate informed decision-making for potential transplant recipients and donors. PMID:25066730

  14. Radiation grafting studies of acrylic acid onto cellulose triacetate membranes

    NASA Astrophysics Data System (ADS)

    Mazzei, R. O.; Smolko, E.; Torres, A.; Tadey, D.; Rocco, C.; Gizzi, L.; Strangis, S.

    2002-05-01

    Polymer surface modifications were obtained by the application of radiation treatments, etching and grafting of acrylic acid monomers on different membranes of cellulose triacetate materials. Cellulose triacetate foils from pellet dissolution and commercial cellulose triacetate solid state nuclear track detector membranes were assayed. Irradiation with fission fragments from Cf-252 source to obtain a porous structure, 25 MeV proton beam and Co-60 γ-source to produce peroxides were employed in the experiments. The present work gives the grafting yield of AAc monomer onto CTA membranes as a function of diverse variables including irradiation parameters ( γ-dose, Cf-252 ff irradiation time, proton fluency and electronic energy loss (d E/d x) e), structural parameters (pore diameter and pore density, etching time and etching temperature) and grafting parameters (monomer and Mohr salt concentration, grafting time and grafting temperature).

  15. 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

  16. Comparison of structural changes in skin and amnion tissue grafts for transplantation induced by gamma and electron beam irradiation for sterilization.

    PubMed

    Mrázová, H; Koller, J; Kubišová, K; Fujeríková, G; Klincová, E; Babál, P

    2016-06-01

    Sterilization is an important step in the preparation of biological material for transplantation. The aim of the study is to compare morphological changes in three types of biological tissues induced by different doses of gamma and electron beam radiation. Frozen biological tissues (porcine skin xenografts, human skin allografts and human amnion) were irradiated with different doses of gamma rays (12.5, 25, 35, 50 kGy) and electron beam (15, 25, 50 kGy). Not irradiated specimens served as controls. The tissue samples were then thawn and fixed in 10 % formalin, processed by routine paraffin technique and stained with hematoxylin and eosin, alcian blue at pH 2.5, orcein, periodic acid Schiff reaction, phosphotungstic acid hematoxylin, Sirius red and silver impregnation. The staining with hematoxylin and eosin showed vacuolar cytoplasmic changes of epidermal cells mainly in the samples of xenografts irradiated by the lowest doses of gamma and electron beam radiation. The staining with orcein revealed damage of fine elastic fibers in the xenograft dermis at the dose of 25 kGy of both radiation types. Disintegration of epithelial basement membrane, especially in the xenografts, was induced by the dose of 15 kGy of electron beam radiation. The silver impregnation disclosed nuclear chromatin condensation mainly in human amnion at the lowest doses of both radiation types and disintegration of the fine collagen fibers in the papillary dermis induced by the lowest dose of electron beam and by the higher doses of gamma radiation. Irradiation by both, gamma rays and the electron beam, causes similar changes on cells and extracellular matrix, with significant damage of the basement membrane and of the fine and elastic and collagen fibers in the papillary dermis, the last caused already by low dose electron beam radiation. PMID:26649556

  17. Quality of life, reproduction and sexuality after stem cell transplantation with partially T-cell-depleted grafts and after conditioning with a regimen including total body irradiation.

    PubMed

    Claessens, J J M; Beerendonk, C C M; Schattenberg, A V M B

    2006-05-01

    Thirty-four men and 36 women (median age 43 and 45 years, respectively) underwent stem cell transplantation (SCT) for acute leukaemia in first complete remission or chronic myelogenous leukaemia in first chronic phase between 1981 and 2001 from HLA-identical siblings. The conditioning regimen included TBI and all grafts were partially depleted of T cells. Changes in quality of life (QOL), reproduction and sexuality were studied using a questionnaire, and the previously given information related to these problems was assessed. In addition, endocrine status was assessed and semen analysis was performed. After SCT, patients reported less energy (n=50) and a deterioration in the job situation (n=31). Patients experienced a negative change in sexual relations (n=41). Important problems of sexual dysfunction were vaginal dryness in women (n=19) and erectile dysfunction in men (n=16). None of the patients was fertile based on their gonadotrophin levels, sperm concentrations and reproductive outcomes. Women experienced climacteric symptoms (n=24). Quality of life was negatively influenced by these changes. One-fifth of the patients were not satisfied with the information given with regard to reproduction, premature menopause and sexual problems. PMID:16547485

  18. Blood irradiation: Rationale and technique

    SciTech Connect

    Lewis, M.C. )

    1990-01-01

    Upon request by the local American Red Cross, the Savannah Regional Center for Cancer Care irradiates whole blood or blood components to prevent post-transfusion graft-versus-host reaction in patients who have severely depressed immune systems. The rationale for blood irradiation, the total absorbed dose, the type of patients who require irradiated blood, and the regulations that apply to irradiated blood are presented. A method of irradiating blood using a linear accelerator is described.

  19. 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. PMID:27256540

  20. Cladribine, gemcitabine, busulfan, and SAHA combination as a potential pretransplant conditioning regimen for lymphomas: A preclinical study.

    PubMed

    Ji, Jie; Valdez, Benigno C; Li, Yang; Liu, Yan; Teo, Esmeralda C; Nieto, Yago; Champlin, Richard E; Andersson, Borje S

    2016-06-01

    Hematopoietic stem cell transplantation (HSCT) is an effective treatment for patients with refractory lymphomas. Nucleoside analogs (NAs) and DNA alkylating agents are efficacious in treating hematologic malignancies. To design an efficacious and more economical pretransplant regimen for lymphoma patients, we analyzed the cytotoxicity of cladribine (Clad), gemcitabine (Gem), busulfan (Bu), and suberoylanilide hydroxamic acid (SAHA) in lymphoma cell lines. J45.01 and U937 lymphoma cell lines were exposed to drugs, alone or in combination, for 48 hours and analyzed with the MTT and annexin V assays, Western blotting, and flow cytometry. On the basis of the IC5-10 values of the drugs, the Clad+Gem+Bu combination inhibited the proliferation of both cell lines to ∼55%-60%. Addition of SAHA to this combination decreased proliferation further to ∼30%. Exposure to the Clad+Gem+Bu+SAHA combination activated the DNA damage response and ATM-CHK2 pathway; modified histones; decreased mitochondrial membrane potential, which caused leakage of apoptosis-inducing factors; and activated apoptosis. Pretreatment of cells with the pan-caspase inhibitor Z-VAD-FMK blocked the phosphorylation of histone 2AX and cleavage of PARP-1 and caspases. The Clad+Gem+Bu+SAHA combination provides synergistic cytotoxicity in lymphoma cell lines. Our results may be a basis for using this combination as a pretransplant conditioning regimen in a clinical trial for lymphoma patients undergoing hematopoietic stem cell transplantation, replacing the more expensive nucleoside analog clofarabine. PMID:26976752

  1. 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

  2. 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.

  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 Central

    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. PMID

  4. 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. PMID

  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. PMID:19576692

  6. Synthesis and characterization of thermo- and pH- sensitive hydrogels based on Chitosan-grafted N-isopropylacrylamide via γ-radiation

    NASA Astrophysics Data System (ADS)

    Cai, Hong; Zhang, Zheng Pu; Chuan Sun, Ping; Lin He, Bing; Xia Zhu, Xiao

    2005-09-01

    Thermo- and pH-sensitive hydrogels were prepared by graft copolymerization of chitosan (CS) and N-isopropylacrylamide via γ-radiation. The effects of monomer concentration and irradiation dose on grafting percentage and grafting efficiency were studied. The graft copolymers were characterized by 13C CP/MAS NMR and thermogravimetric analysis. The pH and thermosensitivity and swelling properties of the hydrogels were investigated. The results showed that the grafting percentage and grafting efficiency increased with the increase of monomer concentration and total irradiation dose. The highest grafting percentage is 620%, the lower critical solution temperature (LCST) of this hydrogel is about 28 °C.

  7. 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

  8. 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. PMID:26359198

  9. 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

  10. 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.

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

    PubMed

    Mahmoodian, Hossein; Moradi, Omid; Shariatzadeh, Behnam

    2014-02-01

    We report a simple method for engineering chitosan (CS) functionalized multi-walled carbon nanotube (MWCNT) composites with a biomedically important polymer, poly-2-hydroxyethyl methacrylate (polyHEMA), by chemical grafting HEMA monomers via free radical polymerization. Functionalization of CS and polyHEMA occurred in three steps. First, using microwave irradiation, CS was grafted onto the surface and sidewall of the carbon nanotubes. Second, HEMA monomers were grafted onto the polymeric matrix surface. The final step involved free radical polymerization of HEMA monomers. Composite synthesis was confirmed by Fourier transform infrared (FTIR) spectroscopy. Moreover, the presence of polyHEMA on the surface of the CS functionalized carbon nanotubes was confirmed by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA) analyses. Furthermore, in the aqueous phase, our novel composites exhibited higher dispersibility compared with pristine MWCNTs. Considering the biomedical importance of polyHEMA and CS polymers, we expect these materials to be useful in the pharmaceutical industry as novel biomaterial composites with potential applications in drug delivery. PMID:24183808

  12. Fulminant transfusion-associated graft-versus-host disease in a premature infant

    SciTech Connect

    Berger, R.S.; Dixon, S.L.

    1989-05-01

    A fatal case of transfusion-associated graft-versus-host disease developed in a premature infant after receiving several blood products, including nonirradiated white blood cells. Transfusion-associated graft-versus-host disease can be prevented. Irradiation of blood products is the least controversial and most effective method. Treatment was unsuccessful in most reported cases of transfusion-associated graft-versus-host disease. Therefore irradiation of blood products before transfusing to patients susceptible to transfusion-associated graft-versus-host disease is strongly recommended.

  13. 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. PMID:26545225

  14. 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.

  15. Radiation graft modification of ethylene-propylene rubber—II. Effect of additives

    NASA Astrophysics Data System (ADS)

    Haddadi-Asl, V.; Burford, R. P.; Garnett, J. L.

    1995-02-01

    The effect of multifunctional acrylic additives including TMPTA, PEGDA and PGTA on the radiation grafting of hydrophilic vinyl monomers onto ethylene—propylene elastomer (EPM rubbers) was studied. This work centres upon gamma irradiation-induced grafting of acrylamide (AAm), N-vinyl-2-pyrrolidone (NVP), 2-hydroxyethyl methacrylate (HEMA) and acrylonitrile (AN) onto EPM rubber by the simultaneous method. Water proved to be an effective solvent but methanol lowered grafting. Sulphuric acid was detrimental to both homopolymerisation and grafting, a result consistent with the theory proposed for the role of this additive in polymer grafting systems.

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

    SciTech Connect

    Jansen, B.; Ellinghorst, G.

    1985-11-01

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

  17. Pretransplant CSF-1 therapy expands recipient macrophages and ameliorates GVHD after allogeneic hematopoietic cell transplantation

    PubMed Central

    Hashimoto, Daigo; Chow, Andrew; Greter, Melanie; Saenger, Yvonne; Kwan, Wing-Hong; Leboeuf, Marylene; Ginhoux, Florent; Ochando, Jordi C.; Kunisaki, Yuya; van Rooijen, Nico; Liu, Chen; Teshima, Takanori; Heeger, Peter S.; Stanley, E. Richard; Frenette, Paul S.

    2011-01-01

    Acute graft-versus-host disease (GVHD) results from the attack of host tissues by donor allogeneic T cells and is the most serious limitation of allogeneic hematopoietic cell transplantation (allo-HCT). Host antigen-presenting cells are thought to control the priming of alloreactive T cells and the induction of acute GVHD after allo-HCT. However, whereas the role of host DC in GVHD has been established, the contribution of host macrophages to GVHD has not been clearly addressed. We show that, in contrast to DC, reducing of the host macrophage pool in recipient mice increased donor T cell expansion and aggravated GVHD mortality after allo-HCT. We also show that host macrophages that persist after allo-HCT engulf donor allogeneic T cells and inhibit their proliferation. Conversely, administration of the cytokine CSF-1 before transplant expanded the host macrophage pool, reduced donor T cell expansion, and improved GVHD morbidity and mortality after allo-HCT. This study establishes the unexpected key role of host macrophages in inhibiting GVHD and identifies CSF-1 as a potential prophylactic therapy to limit acute GVHD after allo-HCT in the clinic. PMID:21536742

  18. Direct pyrolysis mass spectrometry of acrylonitrile-cellulose graft copolymer prepared by radiation-induced graft polymerization in presence of styrene as homopolymer suppressor

    NASA Astrophysics Data System (ADS)

    Badawy, Sayed M.; Dessouki, Ahmad M.; Nizam El-Din, Horia M.

    2001-05-01

    Graft polymerization of acrylonitrile onto cellulosic filter paper competing with the homopolymerization by mutual irradiation technique was studied in the presence of homopolymer suppressors. Addition of FeCl 3 decreased both homopolymerization and graft polymerization, whereas inclusion of a low ratio of styrene monomer with acrylonitrile leads to successful grafting of acrylonitrile with little homopolymer formation. Chemical structure and thermal behavior of the produced graft copolymers were investigated by gradual heating in the solid probe of a mass spectrometer equipped with a GCMS data system. The resulting total ion current (TIC) showed that the degradation of graft copolymers follows two-step pyrolysis. The presence of a low ratio of styrene comonomer increased thermal stability of the prepared acrylonitrile-cellulose graft copolymer. The pyrolysis products have mass spectra characteristic of the copolymer composition; they contain the repeating unit of the oligomers. Total ion current and spectrum subtractions were used to separate and measure spectra of graft copolymers at distinctly different temperatures.

  19. 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

  20. Comparing calvarial transport distraction with and without radiation and fat grafting.

    PubMed

    Yuhasz, Mikell M; Koch, Felix P; Kwiatkowski, Anna; Young, Calvin; Clune, James; Travieso, Rob; Wong, Kenneth; Van Houten, Joshua; Steinbacher, Derek M

    2014-10-01

    The purpose of this study is to: a) assess transport distraction to reconstruct cranial defects in radiated and non-radiated fields b) examine adipose grafting's effect on the bony regenerate and overlying wound, and c) elucidate sources of bone formation during transport distraction osteogenesis. Twenty-three male New Zealand white rabbits (3 months; 3.5 kg) were used, 10 non-irradiated and 13 irradiated (17 treatment, 6 control) with a one-time fraction of 35 Gy. A 16 × 16 mm defect was abutted by a 10 × 16 mm transport disc 5 weeks after irradiation, and 11 animals were fat grafted at the distraction site. Latency (1 day), distraction (1.5 mm/day), and consolidation (4 weeks) followed. Fluorochromes were injected subcutaneously and microCT, fluorescence, and histology assessed. In distracted animals without fat grafting, bone density measured 701.87 mgHA/ccm and 2271.95 mgHA/ccm in irradiated and non-irradiated animals. In distracted animals with fat grafting, bone density measured 703.23 mgHA/ccm and 2254.27 mgHA/ccm in irradiated and non-irradiated animals. Fluorescence revealed ossification emanating from the dura, periosteum, and transport segment with decreased formation in irradiated animals. Transport distraction is possible for cranial reconstruction in irradiated fields but short-term osseous fill is significantly diminished. Adipose grafting enhances wound healing in previously irradiated fields but does not enhance ossification. PMID:24864072

  1. Long-term graft outcomes and patient survival are lower posttransplant in patients with a primary renal diagnosis of glomerulonephritis.

    PubMed

    Pruthi, Rishi; McClure, Mark; Casula, Anna; Roderick, Paul J; Fogarty, Damian; Harber, Mark; Ravanan, Rommel

    2016-04-01

    Glomerulonephritis (GN) is the primary diagnosis in 20% to 40% of patients receiving a renal transplant. Here we studied patient survival and graft outcomes in patients with GN transplanted in the UK. UK Renal Registry data were used to analyze patient survival and graft failure in incident transplant patients between 1997 to 2009 who had a diagnosis of primary GN, in comparison to patients transplanted with adult polycystic kidney disease (APKD) or diabetes. Multivariable regression analysis adjusted for age, sex, donor type, ethnicity, donor age, time on dialysis, human leukocyte antigen mismatch, cold ischemic time, and graft failure (for patient survival). Patients were followed up through December 2012. Of 4750 patients analyzed, 2975 had GN and 1775 APKD. Graft failure was significantly higher in membranoproliferative glomerulonephritis (MPGN) type II (hazard ratio: 3.5, confidence interval: 1.9-6.6), focal segmental glomerulosclerosis (2.4, 1.8-3.2), MPGN type I (2.3, 1.6-3.3), membranous nephropathy (2.0, 1.4-2.9), and IgA nephropathy (1.6, 1.3-2.0) compared to APKD. Survival was significantly reduced in patients with MPGN type II (4.7, 2.0-10.8), and those with lupus nephritis (1.8, 1.1-2.9). Overall graft failure for patients with GN was similar to those with diabetes. Thus, in comparison to outcomes in APKD, graft survival is significantly lower in most GNs, with variation in outcomes between different GNs. This information should assist in pretransplant counseling of patients. Further study is required to understand the reduced survival seen in lupus nephritis and MPGN type II, and to improve overall graft outcomes. PMID:26924061

  2. Biology of cancellous bone grafts.

    PubMed

    Heiple, K G; Goldberg, V M; Powell, A E; Bos, G D; Zika, J M

    1987-04-01

    Despite 30 years of experimental bone grafting research, the fresh cancellous bone graft remains the most osteogenic and reliable bone grafting material. Recent experimental data suggest that modification of the graft-host interaction by antigen matching or immune manipulation may allow increasingly successful use of allografts. PMID:3550570

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Impact of pretransplant serum ferritin level on risk of invasive mold infection after allogeneic hematopoietic stem cell transplantation.

    PubMed

    Dadwal, Sanjeet S; Tegtmeier, Bernard; Liu, Xueli; Frankel, Paul; Ito, James; Forman, Stephen J; Pullarkat, Vinod

    2015-03-01

    Invasive mold infections (IMI) are life-threatening complications of allogeneic hematopoietic stem cell transplantation (HSCT) and are mostly caused by Aspergillus species and Mucorales. We examined whether elevated serum ferritin prior to HSCT was associated with increased risk of IMI after allogeneic HSCT. Elevated serum ferritin was defined as values ≥ 1000 ng/mL. Pretransplant ferritin levels were available for 477 transplants. Nine developed IMI at day 30 and 21 had IMI at day 100 for a cumulative incidence of 1.9% and 4.4%, respectively. Among the high ferritin group, eight of 220 transplant cases (3.6%) developed an IMI within 30 d after HSCT compared with one of 257 (0.4%) in the low ferritin group (P = 0.01). Fourteen of 220 (6.4%) and seven of 257 transplant cases (2.7%) in the high and low ferritin groups, respectively, had developed an IMI by day 100 after HSCT (P = 0.07). Nine of 53 (17%) patients with grades III and IV acute GVHD and iron overload experienced IMI, when compared to three of 37 (8.1%) with high-grade aGVHD, but no iron overload. Among patients without aGVHD, those with elevated ferritin had a 2.7% incidence of IMI compared with 0.9% for patients without elevated ferritin. There was a marginally significant difference in cumulative incidence function between high and low ferritin groups for IMI (P = 0.06). However, elevated serum ferritin (≥ 1000 ng/mL) was not a significant risk factor for IMI in a multivariate competing risk regression model after adjusting for aGVHD. PMID:25082161

  8. 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

  9. Pre-transplant assessment of CMV-specific immune response by Elispot assay in kidney transplant recipients.

    PubMed

    Rittà, Massimo; Costa, Cristina; Sidoti, Francesca; Ballocco, Cinzia; Ranghino, Andrea; Messina, Maria; Biancone, Luigi; Cavallo, Rossana

    2015-07-01

    Cytomegalovirus (CMV) primary infection or re-activation in solid organ transplant (SOT) recipients is associated with increased morbidity and mortality, with patients with IgG-CMV D+/R- sero-matching at greater risk. The impact of pre-transplant CMV-specific host cellular immunity on the long-term risk of CMV replication in kidney transplants (KT) was prospectively evaluated in eighty patients by CMV-EliSpot assay. The study population included 54 male and 26 female recipients, with CMV-IgG distribution: 60 D+/R+, 11 D-/R+, 7 D+/R-, 2 D-/R-. At pre-transplantation, 49 KT (61.3%) were CMV-responders by EliSpot. At 3-month follow up, 16 (32.7%) out of 49 CMV-responders showed CMV blood infection, compared to 8 (25.8%) out of 31 non-responders. No further episode of CMV viraemia was reported in the responder group, in comparison to 15 out 31 non-responders (48.4%) showing at least one episode of CMV-DNAemia at 12-month follow-up. Baseline CMV-IgG serology showed a strong correlation with EliSpot determinations; KT recipients exhibiting at least one episode of CMV viraemia at 12-month follow-up showed lower baseline CMV-EliSpot values than those without signs of CMV replication. The study suggests that monitoring CMV-specific T-cell responses at pre-transplantation by EliSpot assay may be useful for predicting the post-transplantation risk of CMV infection and reactivation. PMID:26147141

  10. 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 ...

  11. Epidermal skin grafting.

    PubMed

    Herskovitz, Ingrid; Hughes, Olivia B; Macquhae, Flor; Rakosi, Adele; Kirsner, Robert

    2016-09-01

    Autologous skin grafts, such as full- and split-thickness, have long been part of the reconstructive ladder as an option to close skin defects. Although they are effective in providing coverage, they require the need for a trained surgeon, use of anaesthesia and operating room and creation of a wound at the donor site. These drawbacks can be overcome with the use of epidermal skin grafts (ESGs), which can be harvested without the use of anaesthesia in an office setting and with minimal to no scarring at the donor site. ESGs consist only of the epidermal layer and have emerged as an appealing alternative to other autologous grafts for the treatment of acute and chronic wounds. In this article, we provide an overview of epidermal grafting and its role in wound management. PMID:27547964

  12. Sizing of crimped Dacron grafts.

    PubMed

    Reid, J D; Sladen, J G

    1992-05-01

    The aim of this study was to correlate the stated size of Dacron grafts (Microvel) with their actual internal diameter and to compare this with measurements by ultrasound in the early postoperative period. Grafts of stated diameters of 7, 8, 9, and 10 mm were studied. Grafts were measured by graded probes and by measuring the width of the longitudinally opened graft and calculating the diameter. Each graft accepted a probe 1 mm larger than its stated size very easily and 2 mm greater when stretched. By open measurement, the grafts were 1.3 to 1.8 mm greater than their stated diameter without stretching. Twenty grafts were studied by duplex ultrasound for diameter and peak systolic velocity within 3 months of implantation. The grafts were 12% larger than their stated graft size. Some of the larger grafts showed low velocity and wall thrombus. We conclude that Microvel grafts are larger than their stated diameter. The same size discrepancy was seen in in vitro measurements of Vascutek (Dacron) grafts but not in polytetrafluoroethylene (Gortex) grafts. Since flow velocity is related to the diameter of the graft, this information should be useful when choosing the diameter of a prosthetic vascular graft. PMID:1533494

  13. [Zaidemberg's vascularized radial graft].

    PubMed

    Saint-Cast, Y

    2010-12-01

    In 1991, Carlos Zaidemberg described a new technique to repair scaphoid non-unions with a vascularized bone graft harvested from the radial styloid process. An anatomic study based on 30 dissections after colorized latex injection established the constancy of the radial styloid process's artery, while showing that its origin, course and length were subject to variations. In a retrospective series of 38 cases over a period of 10 years, the vascularized bone graft was indicated for: (1) scaphoid non-union with the presence of avascular changes of the proximal fragment (23 cases); (2) failed prior reconstruction with bone graft and internal fixation (nine cases); (3) degenerative styloid-scaphoid arthritis (three cases); (4) fracture on Preiser dystrophy (three cases). The five steps of the simplified operative technique without dissection of the vascular pedicle include: (1) longitudinal dorso-radial approach, identification of the periosteal portion of the radial styloid process artery; (2) incision of the first and second compartments, longitudinal arthrotomy under the second compartment; (3) styloidectomy and transversal resection of the scaphoid non-union and sclerotic bone; (4) elevation of the vascularized bone graft; (5) transversal and radial insertion of the vascularized bone graft, osteosynthesis by two or three K-wire touching the scaphoid's radial edge. Scaphoid union was obtained in 33 cases out of 38. The only postoperative complications were two transient radial paresthesia. The standardized surgical procedure using vascularized bone graft harvested from the radial styloid process provides an efficient scaphoid reconstruction. PMID:21087882

  14. Impact of de novo donor-specific anti-HLA antibodies on grafts outcomes in simultaneous pancreas-kidney transplantation.

    PubMed

    Malheiro, Jorge; Martins, La Salete; Tafulo, Sandra; Dias, Leonídio; Fonseca, Isabel; Beirão, Idalina; Castro-Henriques, António; Cabrita, António

    2016-02-01

    De novo donor-specific antibodies (dDSA) relevance in simultaneous pancreas-kidney (SPK) transplantation has been scarcely investigated. We analyzed dDSA relationship with grafts outcomes in a long-term follow-up SPK-transplanted cohort. In 150 patients that received SPK transplant between 2000 and 2013, post-transplant anti-human leukocyte antigen (HLA) antibodies were screened and identified using Luminex-based assays in sera collected at 3, 6, and 12 months, then yearly. dDSA were detected in 22 (14.7%) patients at a median 3.1 years after transplant. Pretransplant anti-HLA sensitization (OR = 4.64), full HLA-DR mismatch (OR = 4.38), and previous acute cellular rejection (OR = 9.45) were significant risk factors for dDSA. dDSA were significantly associated with kidney (in association with acute rejection) and pancreas graft failure. In dDSA+ patients, those with at least one graft failure presented more frequently dDSA against class II or I + II (P = 0.011) and locusDQ (P = 0.043) and had a higher median dDSA number (P = 0.014) and strength (P = 0.030). Median time between dDSA emergence and pancreas and kidney graft failure was 5 and 12 months, respectively. Emergence of dDSA increased the risk of grafts failure in SPK-transplanted patients. Full HLA-DR mismatch was associated with dDSA emergence. dDSA characteristics might help identify patients at a higher risk of graft failure. PMID:26404891

  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. The Science of Hyperbaric Oxygen for Flaps and Grafts.

    PubMed

    Gould, Lisa J; May, Todd

    2016-04-01

    Hyperbaric oxygen (HBO) therapy is a versatile modality that has applications across several medical fields. HBO therapy has become a valuable asset in the management of compromised tissue grafts and flaps. Although classified together, grafts and flaps are distinctly different, in that grafts depend on the wound bed for revascularization, whereas flaps have an inherent blood supply. Evidence has shown that in a compromised graft suffering from hypoxia, HBO can maximize viability and reduce the need for repeat grafting. By comparison, compromised flaps can suffer from both ischemic and reperfusion injury, which can also be attenuated by HBOT to maximize viability. The beneficial effects of HBO occur by several mechanisms, including hyper-oxygenation, fibroblast proliferation, collagen deposition, angiogenesis, and vasculogenesis. Animal studies have demonstrated several of these mechanisms, including an increase in the number, size, and growth distance of blood vessels after HBO. Likewise, clinical studies have found positive responses in multiple types of tissue grafts and flaps, with some cases involving irradiated fields. Altogether, the data emphasizes that early identification of flap or graft compromise is absolutely critical, with maximized chance for viability when HBO is initiated as soon as possible. PMID:27042776

  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. PMID:26526174

  18. Adhesion monitoring of skin grafts by photoacoustic measurement: experiment using rat allograft models

    NASA Astrophysics Data System (ADS)

    Yamazaki, Mutsuo; Sato, Shunichi; Saito, Daizo; Okada, Yoshiaki; Ashida, Hiroshi; Obara, Minoru

    2004-07-01

    Adhesion monitoring of grafted skins is very important in successful treatment of severe burns and traumas. However, current diagnosis of skin grafting is usually done by visual observation, which is not reliable and gives no quantitative information on the skin graft adhesion. When the grafted skin adheres well, neovascularities will be generated in the grafted skin tissue, and therefore adhesion may be monitored by detecting the neovascularities. In this study, we attempted to measure photoacoustic signals originate from the neovascularities by irradiating the grafted skins with 532-nm nanosecond light pulses in rat autograft and allograft models. The measurement showed that immediately after skin grafting, photoacoustic signal originate from the blood in the dermis was negligibly small, while 6 - 24 hours after skin grafting, signal was observed from the dermis in the graft. We did not observe a significant difference between the signals from the autograft and the allograft models. These results indicate that neovascularization would take place within 6 hours after skin grafting, and the rejection reaction would make little effect on adhesion within early hours after grafting.

  19. 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

  20. IMPACT OF PRE-TRANSPLANT RITUXIMAB ON SURVIVAL AFTER AUTOLOGOUS HEMATOPOIETIC STEM CELL TRANSPLANTATION FOR DIFFUSE LARGE B-CELL LYMPHOMA

    PubMed Central

    Fenske, Timothy S.; Hari, Parameswaran N.; Carreras, Jeanette; Zhang, Mei-Jie; Kamble, Rammurti T.; Bolwell, Brian J.; Cairo, Mitchell S.; Champlin, Richard E.; Chen, Yi-Bin; Freytes, César O.; Gale, Robert Peter; Hale, Gregory A.; Ilhan, Osman; Khoury, H. Jean; Lister, John; Maharaj, Dipnarine; Marks, David I.; Munker, Reinhold; Pecora, Andrew L.; Rowlings, Philip A.; Shea, Thomas C.; Stiff, Patrick; Wiernik, Peter H.; Winter, Jane N.; Rizzo, J. Douglas; van Besien, Koen; Lazarus, Hillard M.; Vose, Julie M.

    2010-01-01

    Incorporation of the anti-CD20 monoclonal antibody rituximab into front-line regimens for diffuse large B-cell lymphoma (DLBCL) has resulted in improved survival. Despite this progress, many patients develop refractory or recurrent DLBCL and then receive autologous hematopoietic stem cell transplantation (AuHCT). It is unclear to what extent pre-transplant exposure to rituximab affects outcomes following AuHCT. Outcomes of 994 patients receiving AuHCT for DLBCL between 1996 and 2003 were analyzed according to whether rituximab was (n=176, “+R” group) or was not (n=818, “ −R” group) administered with front-line or salvage therapy prior to AuHCT. The +R group had superior progression-free survival (50% versus 38%, p=0.008) and overall survival (57% versus 45%, p=0.006) at 3 years. Platelet and neutrophil engraftment were not affected by exposure to rituximab. Non-relapse mortality (NRM) did not differ significantly between the +R and −R groups. In multivariate analysis, the +R group had improved progression-free survival (relative risk of relapse/progression or death 0.64, p<0.001) and improved overall survival (relative risk of death of 0.74, p=0.039). We conclude that pre-transplant rituximab is associated with a lower rate of progression and improved survival following AuHCT for DLBCL, with no evidence of impaired engraftment or increased NRM. PMID:19822306

  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. Microstructured polymer films by X-ray lithographic exposure and grafting

    NASA Astrophysics Data System (ADS)

    Gürsel, Selmiye A.; Padeste, Celestino; Solak, Harun H.; Scherer, Günther G.

    2005-07-01

    Recently we reported on a new technique to generate micro- and nanostructured polymer materials by the combination of selective irradiation of polymer substrates with X-rays and subsequent grafting of a second polymer. Here we focus on the spatially defined grafting throughout the thickness of poly(ethylene-alt-tetrafluoroethylene) (ETFE) and poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) films using X-ray irradiation through a metal mask, followed by grafting with styrene. Calculations of the transmission of X-rays through the polymer as a function of the wavelength have revealed that energy deposition within the substrate material, which should control the density of created radicals, can be selected in a wide range. Depending on the used wavelength the radicals are created either near the surface or in the bulk of the sample. First experiments demonstrated spatially defined grafting through a 100 μm thick ETFE film and 25 μm thick FEP film. The achieved graft level depends on the irradiation dose as well as on the grafting parameters such as concentration, temperature and time. The precision of structure definition within the film depends on the properties of the X-ray source, the metal mask and the grafting process. The presented process allows controlled grafting through fluoropolymer films with micrometer resolution and local modification of the properties of the films, such as ion conductivity, diffusion of specific molecules or optical properties.

  3. 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). PMID:23987450

  4. 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.

  5. Grafting Technique to Eliminate Rootstock Suckering of Grafted Tomatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable grafting has been proposed as a technique for avoiding disease problems in tomatoes in open field production. In this study we investigated the current use of grafting in an open field scenario and found a serious problem with the grafting techniques. In the Fall of 2007, commercially pr...

  6. 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

  7. Alveolar bone grafting

    PubMed Central

    Lilja, Jan

    2009-01-01

    In patients with cleft lip and palate, bone grafting in the mixed dentition in the residual alveolar cleft has become a well-established procedure. The main advantages can be summarised as follows: stabilisation of the maxillary arch; facilitation of eruption of the canine and sometimes facilitation of the lateral incisor eruption; providing bony support to the teeth adjacent to the cleft; raising the alar base of the nose; facilitation of closure of an oro-nasal fistula; making it possible to insert a titanium fixture in the grafted site and to obtain favourable periodontal conditions of the teeth within and adjacent to the cleft. The timing of the ABG surgery take into consideration not only eruption of the canine but also that of the lateral incisor, if present. The best time for bone grafting surgery is when a thin shell of bone still covers the soon erupting lateral incisor or canine tooth close to the cleft. PMID:19884665

  8. Light-induced surface graft polymerizations initiated by an anthraquinone dye on cotton fibers.

    PubMed

    Zhuo, Jingyuan; Sun, Gang

    2014-11-01

    Anthraquinone and its derivatives could serve as photo-sensitizers and generate radicals and reactive oxygen species in polymers under exposure of UVA or day light. Such a property was utilized in development of novel light-induced surface radical graft polymerizations on cotton fibers that were dyed with an anthraquinone derivative, 2-ethylanthraquinone. Several functional monomers were directly grafted onto the dyed cotton fibers upon UVA exposure. The chemical and morphological structures and thermal properties of the grafted fibers were confirmed and characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM) and thermal gravimetric analysis (TGA). Reaction conditions including concentrations of the photosensitizer, the amount of monomers, as well as UVA irradiation time could influence grafting efficiencies. More interestingly, the surface graft polymerization did not significantly change the light active functions of the agent, evidenced by the light-active antimicrobial functions of the grafted fibers. PMID:25129730

  9. Skin grafting of the horse.

    PubMed

    Schumacher, J; Hanselka, D V

    1989-12-01

    Free autogenous skin grafting of the horse is indicated for wounds too large to heal by contraction and epithelization. Techniques of pinch, punch, tunnel, and sheet grafting are described. Allografting and storage of skin for delayed grafting are discussed. PMID:2691033

  10. Bone Grafts in Craniofacial Surgery

    PubMed Central

    Elsalanty, Mohammed E.; Genecov, David G.

    2009-01-01

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

  11. 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. PMID:23827580

  12. 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...

  13. Acrylonitrile grafted to PVDF

    SciTech Connect

    Yang, Jin; Eitouni, Hany Basam

    2015-03-31

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

  14. 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

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

    NASA Astrophysics Data System (ADS)

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

    2003-08-01

    The development of alternative prosthetic materials for cardiovascular applications has found growing interest due to the failure to date to be able to implement functional patent small diameter vascular grafts (∅<5 mm). For instance, the successful implantation of small diameter polyester (PET) and expanded polytetrafluoroethylene (PTFEe) vascular grafts has not been achieved in humans. Our stategy is to work with a new multifilament yarns biomaterial, produced from polyvinylidene fluoride (PVDF), which shows suitable mechanical properties, such as a lower tensile modulus than PET and PTFEe. The required biological properties sought for (i.e. low thrombogenicity) could be achieved by "heparin-like" surface modification treatments in order to modify the thrombogenicity levels of the polymeric materials [Ann. Biomed. Eng. 7 (1979) 429]. A four step method is necessary to achieve this "heparin-like" surface transformation [J. Biomed. Mater. Res. 52 (2000) 119]. The first step consists in grafting polystyrene onto the PVDF surface by γ irradiation. The purpose of this study was to evaluate the influence of grafting parameters on the mechanical properties: (i) γ-ray irradiation time and (ii) grafting time of styrene monomers, which polymerize and form polystyrene bound to the PVDF surface.

  16. Autologous Fat Grafting: The Science Behind the Surgery.

    PubMed

    Zielins, Elizabeth R; Brett, Elizabeth A; Longaker, Michael T; Wan, Derrick C

    2016-04-01

    An invaluable part of the plastic surgeon's technical arsenal for soft tissue contouring, fat grafting continues to be plagued by unpredictable outcomes, resulting in either reoperation and/or patient dissatisfaction. Thus, extensive research has been conducted into the effects of adipose tissue procurement, processing, and placement on fat graft quality at both the cellular level and in terms of overall volume retention. Herein, we present an overview of the vast body of literature in these areas, with additional discussion of cell-assisted lipotransfer as a therapy to improve volume retention, and on the controversial use of autologous fat in the setting of prior irradiation. PMID:26961989

  17. Bone grafts and their substitutes.

    PubMed

    Fillingham, Y; Jacobs, J

    2016-01-01

    The continual cycle of bone formation and resorption is carried out by osteoblasts, osteocytes, and osteoclasts under the direction of the bone-signaling pathway. In certain situations the host cycle of bone repair is insufficient and requires the assistance of bone grafts and their substitutes. The fundamental properties of a bone graft are osteoconduction, osteoinduction, osteogenesis, and structural support. Options for bone grafting include autogenous and allograft bone and the various isolated or combined substitutes of calcium sulphate, calcium phosphate, tricalcium phosphate, and coralline hydroxyapatite. Not all bone grafts will have the same properties. As a result, understanding the requirements of the clinical situation and specific properties of the various types of bone grafts is necessary to identify the ideal graft. We present a review of the bone repair process and properties of bone grafts and their substitutes to help guide the clinician in the decision making process. PMID:26733632

  18. Endogenous neural precursors influence grafted neural stem cells and contribute to neuroprotection in the Parkinsonian rat

    PubMed Central

    Madhavan, Lalitha; Daley, Brian F; Sortwell, Caryl E; Collier, Timothy J

    2012-01-01

    Neuroprotective and neurorescue effects after neural stem/precursor cell (NPC) transplantation have been reported, but the mechanisms underlying such phenomena are not well understood. Our recent findings in a rat Parkinson’s disease (PD) model indicate that transplantation of NPCs before a 6-hydroxydopamine (6-OHDA) insult can result in nigrostriatal protection which is associated with endogenous NPC proliferation, migration and neurogenesis. Here, we sought to determine whether the observed endogenous NPC response (1) contributes to transplanted NPC - mediated neuroprotection and/or (2) affects graft phenotype and function. Host Fischer 344 rats were administered the antimitotic agent cytosine-β-D-arabinofuranoside (Ara-C) to eliminate actively proliferating endogenous neural precursors before being transplanted with NPCs and treated with 6-OHDA to induce nigrostriatal degeneration. Behavioral and histological analyses demonstrate that the neuroprotective response observed in NPC transplanted animals which had not received Ara-C was significantly attenuated in animals which did receive pre-transplant Ara-C. Also, while grafts in Ara-C treated animals showed no decrease in cell number, they exhibited significantly reduced expression of the neural stem cell regulators nestin and sonic hedgehog. In addition, inhibition of the endogenous NPC response resulted in an exaggerated host glial reaction. Overall, the study establishes for the first time that endogenous NPCs contribute to transplanted NPC-mediated therapeutic effects by affecting both grafted and mature host cells in unique ways. Thus, both endogenous and transplanted NPCs are important in creating an environment suitable for neural protection and rescue, and harnessing their synergistic interaction may lead to the optimization of cell-based therapies for PD. PMID:22417168

  19. 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.

  20. Comparative study of grafting a polyampholyte in a fluoropolymer membrane by gamma radiation in one or two-steps

    NASA Astrophysics Data System (ADS)

    Estrada-Villegas, G. M.; Bucio, E.

    2013-11-01

    Binary graft copolymerization of pH-sensitive monomers (N,N-dimethylaminoethyl methacrylate, (DMAEMA) and acrylic acid (AAc) onto polyvinylidene fluoride (PVDF) membranes with pore sizes of 0.22 and 0.45 μm was conducted by one and two-steps grafting using a 60Co gamma radiation source (Gammabeam 651 PT). The DMAEMA and AAc monomers were grafted by an oxidative pre-irradiation method in one-step grafting to obtain PDVF-g-(DMAEMA-co-AAc), and both direct irradiation and an oxidative pre-irradiation method were used to obtain the graft copolymer (PVDF-g-DMAEMA)-g-AAc in two-steps grafting. The optimal conditions, such as reaction time, temperature, solvent, monomer concentration and dose, were studied, the aim of this work was to investigate how these factors affecting the graft percent of DMAEMA and AAc prepared in one and two-steps grafting and their structural differences and also characterize the grafting membrane through analytical techniques.

  1. Microwave assisted synthesis and characterization of sodium alginate-graft-poly(N,N'-dimethylacrylamide).

    PubMed

    Akın, Alper; Işıklan, Nuran

    2016-01-01

    Modification of sodium alginate (NaAlg) was carried out using N,N'-dimethylacrylamide (DMAAm) as a monomer and azobisizobutyronitrile (AIBN) as an initiator under microwave irradiation. The effect of reaction conditions such as concentrations of DMAAm, AIBN, NaAlg as well as microwave power and temperature on grafting and grafting efficiency has been explored. Maximum grafting and grafting efficiency has been observed at 1h of grafting time, 0.291 M of DMAAm concentration, 500 W microwave irradiation power, 0.134 M of AIBN concentration, 75°C of reaction temperature and 0.5 g/dL of NaAlg concentration. The grafted copolymer has been characterized by FTIR, DSC, TGA, (13)C NMR, XRD, SEM, and GPC analysis. Cytotoxicity as standard MTT assay, apoptotic and necrotic effects of graft copolymer were investigated on L929 fibroblast cell. It has been found that the grafted copolymer is biocompatible and thermally more stable than the ungrafted alginate. PMID:26549441

  2. 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

  3. 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.

  4. 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.

  5. [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

  6. Protein absorption and fouling on poly(acrylic acid)-graft-polypropylene microfiltration membrane

    NASA Astrophysics Data System (ADS)

    Liu, Yanjun; Ma, Huiying; Lv, Chunying; Yang, Jia; Fu, Xueqi

    2009-07-01

    A series of pH-sensitive poly (acrylic acid)-graft-polypropylene hollow fiber microfiltration membranes were prepared by UV-photo-irradiation. Bovine serum albumin (BSA) was chosen as the model protein to investigate its absorption and fouling behaviors on membranes. The results showed that the hydrophilicity of grafted membrane was improved by poly(acrylic acid) chains with parts of membrane pores blocked. The grafted membranes were markedly pH-dependent on the water permeability as pH was altered from 1 to 11. The zeta potential of grafted membranes calculated by streaming potential was negative in most pH range. Electrostatic interaction energy calculated by DLVO theory showed the electric interaction force between grafted membrane and BSA was attractive. With the rise of grafting degree, the electric attractive force between grafted membrane and BSA increased as pH=3 and decreased as pH=8, while it kept basically unchanged as pH=4.7. As a result, most serious fouling was observed as pH=4.7. Grafted membranes had a lower BSA absorption and better antifouling behavior as pH=8, while the opposite result was revealed as pH=3. In conclusion, the absorption and fouling behavior of BSA on membranes was pH-dependent due to the pH-dependence of membrane charge, and the conformation of BSA and grafting chains.

  7. 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.

  8. 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.

  9. 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.

  10. Radiation grafting of N,N‧-dimethylacrylamide and 2-hydroxyethylmethacrylate onto polypropylene films by one step method

    NASA Astrophysics Data System (ADS)

    Morales-Wiemer, E. A.; Macossay, J.; Bucio, E.

    2013-03-01

    The work presented herein reports on polypropylene films grafted with N,N'-dimethylacrylamide and 2-hydroxyethylmethacrylate. The grafted films were obtained by an oxidative pre-irradiation method in one step using a gamma source of 60Co. The optimal conditions such as reaction time, monomer concentrations and radiation doses were investigated. Characterization of the grafted polymers was carried out through FTIR-ATR, TGA, DSC, and swelling. Grafts onto polymeric films between 10 and 850% were obtained at doses from 20 to 150 kGy and a dose rate of 8.3 kGy/h.

  11. 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. PMID:26344305

  12. 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

  13. 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.

  14. Grafting techniques for Peyronie's disease.

    PubMed

    Hatzichristodoulou, Georgios

    2016-06-01

    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 the aim

  15. Applications of skin grafting in large animals.

    PubMed

    Wilson, D G

    1990-09-01

    Injuries involving full-thickness skin wounds are common in large animals. Skin grafting can shorten the healing time and improve the cosmetic result. Techniques that have been used successfully in the management of full-thickness skin wounds include full-thickness skin grafts, split-thickness skin grafts, tunnel grafts, pinch/punch grafts, and immediate split-thickness skin grafts. The technical aspects of each of these procedures are detailed and representative cases are presented. PMID:2134606

  16. 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.

  17. 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

  18. 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.

  19. Gluteus augmentation with fat grafting.

    PubMed

    Perén, P A; Gómez, J B; Guerrerosantos, J; Salazar, C A

    2000-01-01

    This study presents the authors' experience with gluteus augmentation with autologus fat grafts and liposuction methods, having recorded the evolution of gluteus reshaping with autologus intramuscular fat graft injections for the past 5 years. Preoperative shape is discussed and patient evaluations, operative techniques, postoperative management, and longterm results are emphasized. PMID:11246428

  20. 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...

  1. 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

  2. [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

  3. ACL Reconstruction: Choosing the Graft

    PubMed Central

    Cerulli, Giuliano; Placella, Giacomo; Sebastiani, Enrico; Tei, Matteo Maria; Speziali, Andrea; Manfreda, Francesco

    2013-01-01

    Summary Rupture of the anterior cruciate ligament is one of the most common ligament injuries in sports traumatology. The need for surgical anterior cruciate ligament reconstruction is justified by its anatomical characteristics. Key considerations when choosing a graft include the potential for bone integration and the risk of failure. Bone sclerosis around the tunnel affects the integration of the graft. For this reason, one aspect upon which orthopedic surgeons should focus is the biology of the bone-graft interface. Although the BPTB graft is still used, hamstrings and synthetic grafts have become increasingly widespread and popular over the years. An allograft certainly requires more long-term follow-up to validate its use in response to functional, clinical and biological requirements. PMID:25606507

  4. 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.

  5. Raman spectroscopic study of the repair of surgical bone defects grafted or not with biphasic synthetic micro-granular HA + β-calcium triphosphate irradiated or not with λ850 nm LED light.

    PubMed

    Soares, Luiz Guilherme P; Marques, Aparecida Maria C; Guarda, Milena G; Aciole, Jouber Mateus S; Andrade, Aline S; Pinheiro, Antonio Luiz B; Silveira, Landulfo

    2014-11-01

    The handling of bone losses due to different etiologic factors is difficult and many techniques are aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (~960, ~1,070, and 1,077 cm(-1)) and organic (~1,454 and ~1,666 cm(-1)) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of sacrifice (15 and 30 days). Surgical 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 LED, the defect filled with the clot was further irradiated. On animals of groups biomaterial and LED + biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ850 ± 10 nm, 150 mW, Φ ~ 0.5 cm(2), 20 J/cm(2)-session, 140 J/cm(2)-treatment) at 48-h intervals and repeated for 2 weeks. At both 15th and 30th days following sacrifice, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensity of hydroxyapatite (HA) (~960 cm(-1)) were higher on group LED + biomaterial and the peaks of both organic content (~1,454 and ~1,666 cm(-1)) and transitional HA (~1,070 and ~1,077 cm(-1)) were lower on the same group. It is concluded that the use of LED phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of HA measured by Raman spectroscopy. PMID:25027176

  6. Methods of fiber surface grafting for interphase design and tailored composite response

    NASA Astrophysics Data System (ADS)

    Arnold, Jesse Judson

    1997-11-01

    The objective of this research was to develop methods of fiber surface grafting for interphase formation, and to experimentally evaluate and model these interphases in order to further elucidate their role in fiber-reinforced composites. Surface modification by sp{60}Co gamma irradiation was used initially to graft acrylic polymers on the surface of ultra-high modulus (UHMPE) fibers. This technique utilized low dose rates and low total doses, and achieved grafting with retention of the exceptional UHMPE properties. The surface properties of the fibers were evaluated using fourier transform infra-red spectroscopy (FTIR), electron spectroscopy for chemical analysis (ESCA), and mechanical tests and dynamic mechanical spectrometry (DMS) of discontinuous fiber composites. Depending on the glass transition temperature, Tg, and chemical structure of the graft, the fiber/matrix adhesion and the interfacial failure mechanism was tailored to provide either enhanced reinforcement or toughening. Using a three-phase block model, the DMS characteristics of the composites were modeled and the reinforcement efficiencies extrapolated as a function of surface treatment. The model successfully predicts the tan delta response of the composite and the appearance of additional loss dispersions associated with the interphase. However, the interactions between the high-energy gamma radiation and the fiber and grafts yield interphases that are difficult to characterize and control. The hydroperoxidation grafting method was subsequently developed, which permitted the grafting of tethered, linear chains by a free radical-type polymerization. Poly(styrene-stat-acrylonitrile) was grafted initially, in which the nitrogen in acrylonitrile was used as a marker to verify grafting and to estimate the grafting efficiency by ESCA analysis. Tapping modesp{TM} atomic force microscopy (TMAFM) images of the grafted fibers revealed a nodular surface topography with dimensions that were correlated to the

  7. Liver Transplantation for Alcoholic and Nonalcoholic Fatty Liver Disease: Pretransplant Selection and Posttransplant Management.

    PubMed

    Siddiqui, M Shadab; Charlton, Michael

    2016-06-01

    Alcoholic fatty liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are common causes of chronic liver disease throughout the world. Although they have similar histologic features, a diagnosis of NAFLD requires the absence of significant alcohol use. ALD is seen commonly in patients with a long-standing history of excessive alcohol use, whereas NAFLD is encountered commonly in patients who have developed complications of obesity, such as insulin resistance, hypertension, and dyslipidemia. Lifestyle contributes to the development and progression of both diseases. Although alcohol abstinence can cause regression of ALD, and weight loss can cause regression of NAFLD, many patients with these diseases develop cirrhosis. ALD and NAFLD account for nearly 30% of liver transplants performed in the United States. Patients receiving liver transplants for ALD or NAFLD have similar survival times as patients receiving transplants for other liver disorders. Although ALD and NAFLD recur frequently after liver transplantation, graft loss from disease recurrence after transplantation is uncommon. Cardiovascular disease and de novo malignancy are leading causes of long-term mortality in liver transplant recipients with ALD or NAFLD. PMID:26971826

  8. Electron-beam induced RAFT-graft polymerization of poly(acrylic acid) onto PVDF

    NASA Astrophysics Data System (ADS)

    Grasselli, M.; Betz, N.

    2005-07-01

    This paper explores for the first time the post-radiation-induced-graft polymerization on solid substrate using reversible addition-fragmentation transfer (RAFT) mechanism. Radiation-induced graft polymerization onto polymers is a potentially interesting technique to create easily new materials from highly resistant polymers, e.g. surface graft polymerization of acrylic acid (AA) onto poly(vinylidene difluoride) (PVDF) improves its surface properties without losing its excellent mechanical properties. As a consequence of the radical nature of the polymerization processes it is difficult to control molecular weight of grafted chains, and therefore design and standardize the properties of the final product. RAFT polymerization is a suitable method to obtain monodisperse polymers. The ability of the RAFT agents to control the polymer chain length could be an interesting approach to improve the grafted polymers obtained by post-radiation-induced-graft polymerization technique. In this way, graft polymerization of AA onto electron-beam irradiated α-PVDF was performed using trithiocarbonic acid bis(1-phenylethyl) ester as a RAFT agent to control the radical polymerization. We studied several grafting parameters such as solvent, monomer concentration and grafting time in order to achieve a poly(acrylic acid) (PAA) layer onto PVDF surface. Acetic acid was found to be the best solvent for many reasons, as to drive graft polymerization mainly to the polymer surface, complete solubility and stability of all reactants. Hydrolysis of PAA chains was also studied in order to remove the trithiocarbonate functionality from the grafted polymer. A mild chemical condition was achieved in order to have thiol groups that were detected onto the modified PVDF by specific enzymatic reaction.

  9. 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.

  10. Radiation-induced graft polymerization of maleic acid and maleic anhydride onto ultra-fine powdered styrene butadiene rubber (UFSBR)

    NASA Astrophysics Data System (ADS)

    Peng, Jing; Xia, Haibing; Zhai, Maolin; Li, Jiuqiang; Qiao, Jinliang; Wei, Genshuan

    2007-11-01

    The functionalization of ultra-fine powdered styrene-butadiene rubber (UFSBR) was carried out using gamma radiation-induced graft polymerization of maleic acid (MA) and maleic anhydride (MAH), respectively. It was found that the graft yield of MA onto UFSBR increased rapidly up to the peak and then decreased with increasing MA content. Moreover, the peak shifted to the direction of lower MA content with increasing absorbed dose. Similarly, there was the peak of graft yield with increasing MAH content for grafting of MAH onto UFSBR, whereas the peak of graft yield was achieved at 10 wt% MAH content at different absorbed doses. On the other hand, increasing absorbed dose and decreasing monomer contents are useful to improve the graft efficiency of MA and MAH. At high dose and low monomer content, the graft yield of MAH onto UFSBR is higher than that of MA. FTIR spectra confirmed that both MA and MAH can be grafted successfully onto the UFSBR under gamma irradiation, respectively. Comparing with maleation of rubber by melt grafting, the graft yield of MAH on UFSBR is higher, which can be attributed to the network structure and nanometer size of UFSBR as well as high energy provided by radiation.

  11. Long Term Clinical Outcome of Patients with Severe Combined Immunodeficiency who Received Related Donor Bone Marrow Transplants without Pre-transplant Chemotherapy or Post-transplant GVHD Prophylaxis

    PubMed Central

    Railey, Mary Dell; Lokhnygina, Yuliya; Buckley, Rebecca H.

    2009-01-01

    Objective To determine long term health benefits of non-ablative bone marrow transplantation for severe combined immunodeficiency (SCID), we investigated our cohort of 161 related donor bone marrow transplanted SCID patients. Only 16 (10%) had HLA-identical donors. Study design All 124 survivors were sent questionnaires about their current clinical statuses. Details from clinic visits were also compiled. One hundred eleven patients (90%) were reached. We compared outcomes of patients transplanted before and after 3.5 months of life and by molecular defect. Results The overall survival rate is 77%, but the rate for the 48 infants transplanted in the first 3.5 months of life is 94%, compared with 70% for the 113 transplanted after 3.5 months (p=0.002). Twenty-eight (76%) of the 37 deceased patients died from viral infections present at diagnosis. One or more clinical problems were reported to have been present in the past two years in 71 (64%) of the survivors, although 95 (86%) are considered healthy by their families. Conclusions Most patients with SCID transplanted with related donor marrow without pre-transplant chemotherapy have done well long-term, but those transplanted at <3.5 months of age had a superior survival rate, a lower rate of clinical problems, less need for booster transplants and better nutritional status. PMID:19818451

  12. Prognostic relevance of pretransplant Deauville score on PET-CT and presence of EBV DNA in patients who underwent autologous stem cell transplantation for ENKTL.

    PubMed

    Lim, S H; Hyun, S H; Kim, H S; Lee, J Y; Yoo, K H; Jung, K S; Song, H-N; Cho, J; Park, S; Ko, Y H; Kim, S J; Choi, J Y; Kim, W S

    2016-06-01

    High-dose chemotherapy and autologous stem cell transplantation (ASCT) for extranodal natural killer/T-cell lymphoma (ENKTL) is a reasonable option for a subset of patients. The impact of response status, according to positron emission tomography/computed tomography (PET/CT) results and/or presence of circulating EBV DNA prior to ASCT, has not yet been established. We analyzed 27 ENKTL patients with pre-ASCT circulating EBV DNA who had undergone pre-ASCT PET/CT between 2009 and 2014. We classified patients into two groups based on the result of pretransplantation assessment: a favorable risk group (pretransplant five-point Deauville score (DS) of 1-2 based on PET/CT and no detectable EBV DNA) and an unfavorable risk group (DS 1-2 with detectable EBV DNA, DS 3-5 with or without detectable EBV DNA). After a median follow-up of 37 months, overall survival and PFS were significantly different between the two groups (median OS: not reached for favorable risk group vs 7.0 months for unfavorable risk group, P=0.017; median PFS: 16.0 vs 5.0 months, P=0.019). Multivariate analysis revealed that pre-ASCT DS and EBV DNA was the only independent prognostic factor considering stage, IPI and NKPI. Precise assessment of the status of disease before transplantation may provide more benefit from ASCT to ENKTL patients. PMID:26855154

  13. Secondary alveolar bone grafting: our experience with olecranon bone graft.

    PubMed

    Nadal, Emmanuela; Sabás, Mariana; Dogliotti, Pedro; Espósito, Raquel

    2010-03-01

    Management of alveolar cleft has dramatically changed during the last century: secondary alveolar bone grafting is now an integral part of cleft palate and craniofacial center's protocols. The objectives of alveolar repair and bone grafting are as follows: providing a continuous and stable maxillary dental arch, closure of oronasal fistulae, adequate bone for tooth eruption or orthodontic movement, and nasal base support, improving facial aesthetic. Although cancellous iliac bone is the donor site selected more frequently, bone grafts harvested from different sites have been advocated to decrease donor site morbidity.The aim of this study was to propose and evaluate the use of olecranon as a donor site in 24 patients with secondary alveolar cleft. The graft is taken as a single piece to fit the alveolar cleft defect, and it includes periosteum and corticocancellous bone to improve early vascularization and greater volume maintenance. PMID:20186086

  14. Use of lymphokine-activated killer cells to prevent bone marrow graft rejection and lethal graft-vs-host disease

    SciTech Connect

    Azuma, E.; Yamamoto, H.; Kaplan, J. )

    1989-09-01

    Prompted by our recent finding that lymphokine-activated killer (LAK) cells mediate both veto and natural suppression, we tested the ability of adoptively transferred LAK cells to block two in vivo alloreactions which complicate bone marrow transplantation: resistance to transplanted allogeneic bone marrow cells, and lethal graft-vs-host disease. Adoptive transfer of either donor type B6D2 or recipient-type B6 lymphokine-activated bone marrow cells, cells found to have strong LAK activity, abrogated or inhibited the resistance of irradiated B6 mice to both B6D2 marrow and third party-unrelated C3H marrow as measured by CFU in spleen on day 7. The ability of lymphokine-activated bone marrow cells to abrogate allogeneic resistance was eliminated by C lysis depletion of cells expressing asialo-GM1, NK1.1, and, to a variable degree, Thy-1, but not by depletion of cells expressing Lyt-2, indicating that the responsible cells had a LAK cell phenotype. Similar findings were obtained by using splenic LAK cells generated by 3 to 7 days of culture with rIL-2. Demonstration that allogeneic resistance could be blocked by a cloned LAK cell line provided direct evidence that LAK cells inhibit allogeneic resistance. In addition to inhibiting allogeneic resistance, adoptively transferred recipient-type LAK cells prevented lethal graft-vs-host disease, and permitted long term engraftment of allogeneic marrow. Irradiation prevented LAK cell inhibition of both allogeneic resistance and lethal graft-vs-host disease. These findings suggest that adoptive immunotherapy with LAK cells may prove useful in preventing graft rejection and graft-versus-host disease in human bone marrow transplant recipients.

  15. 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. PMID:26116934

  16. 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.

  17. 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. ...

  18. Experience of injected fat grafting.

    PubMed

    Matsudo, P K; Toledo, L S

    1988-02-01

    Eighteen months' experience with the injected fat grafting technique used in 208 patients to correct various problems such as buttocks (augmentation and reshaping), trochanteric depressions, breast augmentation, scar depressions, thighs and legs (calf and ankle augmentation), small wrinkles and depressions of the face (Romberg's disease), nasolabial fold, upper outer breast quadrant, liposuction sequela, fingers and hands is presented. This method shows major advantages with few complications. Some technical details and recommendations for successful fat grafting are also presented. PMID:3376783

  19. Predicting renal recovery after liver transplant with severe pretransplant subacute kidney injury: The impact of warm ischemia time.

    PubMed

    Laskey, Heather L; Schomaker, Nathan; Hung, Kenneth W; Asrani, Sumeet K; Jennings, Linda; Nydam, Trevor L; Gralla, Jane; Wiseman, Alex; Rosen, Hugo R; Biggins, Scott W

    2016-08-01

    Identifying which liver transplantation (LT) candidates with severe kidney injury will have a full recovery of renal function after liver transplantation alone (LTA) is difficult. Avoiding unnecessary simultaneous liver-kidney transplantation (SLKT) can optimize the use of scarce kidney grafts. Incorrect predictions of spontaneous renal recovery after LTA can lead to increased morbidity and mortality. We retrospectively analyzed all LTA patients at our institution from February 2002 to February 2013 (n = 583) and identified a cohort with severe subacute renal injury (n = 40; creatinine <2 mg/dL in the 14-89 days prior to LTA and not on renal replacement therapy [RRT] yet, ≥2 mg/dL within 14 days of LTA and/or on RRT). Of 40 LTA recipients, 26 (65%) had renal recovery and 14 (35%) did not. The median (interquartile range) warm ischemia time (WIT) in recipients with and without renal recovery after LTA was 31 minutes (24-46 minutes) and 39 minutes (34-49 minutes; P = 0.02), respectively. Adjusting for the severity of the subacute kidney injury with either Acute Kidney Injury Network or Risk, Injury, Failure, Loss, and End-Stage Kidney Disease criteria, increasing WIT was associated with lack of renal recovery (serum creatinine <2 mg/dL after LTA, not on RRT), with an odds ratio (OR) of 1.08 (1.01-1.16; P = 0.03) and 1.09 (1.01-1.17; P = 0.02), respectively. For each minute of increased WIT, there was an 8%-9% increase in the risk of lack of renal recovery after LTA. In a separate cohort of 98 LTA recipients with subacute kidney injury, we confirmed the association of WIT and lack of renal recovery (OR, 1.04; P = 0.04). In LT candidates with severe subacute renal injury, operative measures to minimize WIT may improve renal recovery potentially avoiding RRT and the need for subsequent kidney transplant. Liver Transplantation 22 1085-1091 2016 AASLD. PMID:27302834

  20. Interventions in Infrainguinal Bypass Grafts

    SciTech Connect

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

    2006-02-15

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

  1. 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

  2. Bilateral internal thoracic artery grafting

    PubMed Central

    2013-01-01

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

  3. Primary Graft Dysfunction

    PubMed Central

    Christie, Jason D

    2014-01-01

    Primary graft dysfunction (PGD) is a syndrome encompassing a spectrum of mild to severe lung injury that occurs within the first 72 hours after lung transplantation. PGD is characterized by pulmonary edema with diffuse alveolar damage that manifests clinically as progressive hypoxemia with radiographic pulmonary infiltrates. In recent years, new knowledge has been generated on risks and mechanisms of PGD. Following ischemia and reperfusion, inflammatory and immunological injury-repair responses appear to be key controlling mechanisms. In addition, PGD has significant impact on short- and long-term outcomes; therefore, the choice of donor organ is impacted by this potential adverse consequence. Improved methods of reducing PGD risk and efforts to safely expand the pool are being developed. Ex-vivo lung perfusion is a strategy which may improve risk assessment and become a promising platform to implement treatment interventions to prevent PGD. This review will detail recent updates in the epidemiology, pathophysiology, molecular and genetic biomarkers and state-of-the-art technical developments affecting PGD. (158 words) PMID:23821506

  4. Preparation and characterization of poly(isobutyl methacrylate) microbeads with grafted amidoxime groups

    NASA Astrophysics Data System (ADS)

    Çaykara, Tuncer; Alaslan, Şerife Şirin; Gürü, Metin; Bodugöz, Hatice; Güven, Olgun

    2007-10-01

    Poly(isobutyl methacrylate) (PiBMA) microspheres with a 800- to 1500-μm diameter range synthesized by suspension polymerization technique were used as the trunk polymer in the preparation of a highly efficient new adsorbent. Glycidyl methacrylate (GMA) was grafted onto the trunk polymer by pre-irradiation grafting technique. Grafting conditions were optimized, and GMA grafted PiBMA beads were modified with iminodiacetonitrile (IDAN) in ethanol at 80 °C. The nitrile groups were then amidoximated by using 6% (m/v) hydroxylamine hydrochloride in methanol solution. The IDAN modification and the conversion of the nitrile groups to amidoxime were followed by FT-IR spectroscopy. The surface morphology and thermal behavior of the PiBMA and its modificated forms were also characterized by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques further confirming modification and amidoximation.

  5. Synthesis, characterization and evaluation of methacrylamide grafted gellan as sustained release tablet matrix.

    PubMed

    Nandi, Gouranga; Patra, Poushali; Priyadarshini, Rosy; Kaity, Santanu; Ghosh, Lakshmi Kanta

    2015-01-01

    In the present study, the microwave induced synthesis of polymethacrylamide-grafted-gellan gum (PMaa-g-GG) was carried out by free radical initiation using cerric (IV) ammonium nitrate (CAN) as redox initiator. Concentrations of methacrylamide (Maa), CAN and microwave irradiation time were taken as variable synthetic parameters. The modified polysaccharide obtained from different synthetic conditions was then characterized by FTIR, CHN analysis, DSC and powder X-ray diffraction. The yield and extent of grafting were assessed by determining percentage grafting, percentage grafting efficiency, percentage conversion and these were correlated with elemental analysis. The acute oral toxicity study of modified polysaccharide was performed as per OECD guideline. Histological comparison of different organs between control and test animal showed no significant difference. Sustained release tablets of diclofenac sodium (DS) were prepared with modified gellan. In vitro dissolution study showed the tablets were capable of releasing the drug over a period of 8 h. PMID:25316428

  6. 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.

  7. 2006 Frank Stinchfield Award: grafting of biocompatible polymer for longevity of artificial hip joints.

    PubMed

    Moro, Toru; Takatori, Yoshio; Ishihara, Kazuhiko; Nakamura, Kozo; Kawaguchi, Hiroshi

    2006-12-01

    Aseptic loosening induced by wear particles from the polyethylene liner is likely the most common cause of long-term total hip arthroplasty failure. We developed a novel hip polyethylene liner with the surface graft of a biocompatible phospholipid polymer, 2-methacryloyloxyethyl phosphorylcholine (MPC), and previously reported the grafting decreased the short-term production of wear particles and the subsequent bone resorptive responses. For clinical application, we investigated the stability of the 2-methacryloyloxyethyl phosphorylcholine grafting during sterilization and the wear resistance of the sterilized liner during longer loading comparable to clinical usage. Radiographic spectroscopy confirmed the stability of the 2-methacryloyloxyethyl phosphorylcholine polymer on the liner surface after the gamma irradiation. We used a hip wear simulator up to 1 x 10(7) cycles to test sterilized cross-linked polyethylene liners with and without 2-methacryloyloxyethyl phosphorylcholine grafting. The 2-methacryloyloxyethyl phosphorylcholine grafting markedly decreased the friction, the production of wear particles, and the wear of the liner surface. These data suggest a marked improvement in the wear resistance of the polyethylene liner by the 2-methacryloyloxyethyl phosphorylcholine grafting for clinically relevant periods after sterilization, indicating 2-methacryloyloxyethyl phosphorylcholine grafting is a promising technology for extending longevity of artificial hips. PMID:17053564

  8. Radiation grafting of acrylamide onto starch-filled low density polyethylene

    NASA Astrophysics Data System (ADS)

    Bagheri, Rouhallah; Naimian, Franak; Sheikh, Nassrin

    1997-04-01

    Acrylamide (AAm) was grafted on the surface of starch-filled low density polyethylene (SLDPE) and low density polyethylene (LDPE) films by the mutual irradiation technique at doses from 0.75 to 5 kGy. The effect of dose, solvents and dihydroxybenzoquinone on the degree of grafting was studied by Fourier transform infrared spectroscopy and the weight measurement method of extracted films at a constant monomer concentration (10% w/w). An ultraviolet spectrophotometer was also used to elucidate the results of the above methods. Grafting on SLDPE and LDPE samples reaches a maximum followed by a slight decrease with increasing dose. A higher degree of grafting was obtained on SLDPE samples compared with that on LDPE. An induction period was observed in the case of the samples prepared in tetrahdyrfuran (THF) as the solvent compared with those in chloroform. Addition of benzene to chloroform and THF (50% v/v) accelerates the rate of AAm grafting on the samples. Dihydroxybenzoquinone inhibits the grafting reactions of the samples especially in the THF solutions. The water uptake measurement of the samples correlates with the degree of grafting.

  9. 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

  10. A spun elastomeric graft for dialysis access.

    PubMed

    Drasler, W J; Wilson, G J; Stenoien, M D; Jenson, M L; George, S A; Dutcher, R G; Possis, Z C

    1993-01-01

    A new composite vascular graft was developed using electrostatic spinning technology. The graft is primarily microfibrous polydimethylsiloxane spun onto a mandrel; a small diameter polyester yarn provides additional strength while minimizing wall thickness, and a helical bead provides crush and kink resistance. Eighteen grafts were implanted in a mongrel canine arteriovenous shunt model for 12 months. The grafts were implanted in femoral artery to femoral vein loops and were cannulated using three pairs of 16 gauge dialysis needles per week. Grafts were evaluated during each puncture session, and also followed using angiography. Histologic study of explanted grafts, regional lymph nodes, and lungs was performed. The grafts provided excellent handling and puncture characteristics, with no bleeding through the graft wall at puncture sites. Cumulative patency of these punctured grafts was 88% at 6 months and 80% at 1 year. Histologic study showed external fibroconnective tissue encapsulation of the grafts, with tissue growth through the interstices of the graft consisting of a microvascular network surrounded predominantly by histiocytes, many multinucleated foreign body giant cells, with some fibroblasts and collagen formation also present. Little luminal thrombus was seen at puncture sites in the patent grafts, and there was no evidence of pulmonary thromboemboli. This new elastomeric graft shows excellent promise for dialysis access; similar grafts under development may also find application for small diameter peripheral vascular reconstruction. PMID:8324257

  11. Engineered Water Highways in Fuel Cells: Radiation Grafting of Gas Diffusion Layers.

    PubMed

    Forner-Cuenca, Antoni; Biesdorf, Johannes; Gubler, Lorenz; Kristiansen, Per Magnus; Schmidt, Thomas Justus; Boillat, Pierre

    2015-11-01

    A novel method to produce gas diffusion layers with patterned wettability for fuel cells is presented. The local irradiation and subsequent grafting permits full design flexibility and wettability tuning, while modifying throughout the whole material thickness. These water highways have improved operando performance due to an optimized water management inside the cells. PMID:26395373

  12. 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.

  13. Polyethylene terephthalate membrane grafted with peptidomimetics: endothelial cell compatibility and retention under shear stress.

    PubMed

    Rémy, Murielle; Bareille, Reine; Rerat, Vincent; Bourget, Chantal; Marchand-Brynaert, Jacqueline; Bordenave, Laurence

    2013-01-01

    The present work aimed to treat a polyethylene terephthalate (PET) surface to make the biomaterial more 'attractive' in terms of attachment and shear stress response to endothelial cells with a view to possible applications in vascular grafting. A surface wet-chemistry protocol was applied to graft track-etched PET membranes with RGD peptidomimetics based on the tyrosine template and active at the nano-level vs. isolated human αvβ3 receptor, which was monitored by X-ray photoelectron spectroscopy, contact angle measurement and atomic force microscopy for characterization. A primary culture of human saphenous vein endothelial cells was used before and after sterilization of the membranes (heat treatment or γ-ray irradiation) to test the benefit of grafting. The optimal surface concentrations of grafted molecules were around 50 pmol/cm². Compared to GRGDS, the peptidomimetics promoted cell attachment with similar or slightly better performances. Endothelialized grafted supports were further exposed to 2 h of shear stress mimicking arterial conditions. Cells were lost on non-grafted PET whereas cells on grafted polymers sterilized by γ-ray irradiation withstood forces with no significant difference in focal contacts. At the mRNA level, cells on functionalized PET were able to respond to shear stress with NFkB upregulation. Thus, grafting of peptidomimetics as ligands of the αvβ3 integrin could be a relevant strategy to improve the adhesion of human endothelial cells and to obtain an efficient endothelialized PET for the surgery of small-diameter vascular prostheses. PMID:23565647

  14. Prognostic Value of the Pre-Transplant Diastolic Pulmonary Artery Pressure to Pulmonary Capillary Wedge Pressure Gradient (DPG) in Cardiac Transplant Recipients with Pulmonary Hypertension

    PubMed Central

    Tedford, Ryan J.; Beaty, Claude A.; Mathai, Stephen C.; Kolb, Todd M.; Damico, Rachel; Hassoun, Paul M.; Leary, Peter J.; Kass, David A.; Shah, Ashish S.

    2014-01-01

    Background Although the transpulmonary gradient (TPG) and pulmonary vascular resistance (PVR) are commonly used to differentiate heart failure patients with pulmonary vascular disease from those with passive pulmonary hypertension (PH), elevations in TPG and PVR may not always reflect pre-capillary PH. Recently, it has been suggested an elevated diastolic pulmonary artery pressure to pulmonary capillary wedge pressure gradient (DPG) may be better indicator of pulmonary vascular remodeling, and therefore, may be of added prognostic value in patients with PH being considered for cardiac transplantation. Methods Utilizing the United Network for Organ Sharing (UNOS) database, we retrospectively reviewed all primary adult (age >17 years) orthotropic heart transplant recipients between 1998–2011. All patients with available pre-transplant hemodynamic data and PH (mean pulmonary artery pressure ≥ 25mmHg were included (n=16,811). We assessed the prognostic value of DPG on post-transplant survival in patients with PH and an elevated TPG and PVR. Results In patients with PH and a TPG > 12mmHg (n=5,827), there was no difference in survival at up to 5 years post-transplant between high (defined as ≥3, ≥5, ≥7, or ≥10mmHg) and low DPG groups (<3, <5, <7, or <10mmHg). Similarly, there was no difference in survival between high and low DPG groups in those with a PVR > 3 wood units (n=6,270). Defining an elevated TPG as > 15mmHg (n=3,065) or an elevated PVR > 5 (n=1783) yielded similar results. Conclusions In the largest analysis to date investigating the prognostic value of DPG, an elevated DPG had no impact on post-transplant survival in patients with PH and an elevated TPG and PVR. PMID:24462554

  15. 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. PMID:25862589

  16. Developments at the graft interface in homo- and hetero-grafts

    PubMed Central

    Clemente Moreno, Maria José; Hevin, Cyril; Ollat, Nathalie; Cookson, Sarah Jane

    2014-01-01

    Gene expression changes induced during graft union formation (the first month after grafting) in grapevine have been studied using whole genome microarrays. The genes differentially expressed between the rootstock and graft interface tissues of homo-grafts (Cabernet Sauvignon (CS) grafted onto CS) were compared at 3 and 28 days after grafting (dag). Graft union formation was associated with the upregulation of genes involved in secondary metabolism, cell wall, wound responses and hormone signaling. These gene expression differences were associated with the accumulation of lignin, cellulose and callose in the callus cells. Superimposed upon this, hetero-grafting between two different grapevine genotypes resulted in the further upregulation of stress and/or defense responses at the graft interface. Here we discuss the limitations of the techniques used to study the developments at the graft interface to date and future research directions to understand graft union formation in plants. PMID:24770337

  17. Saphenous vein forearm grafts and gortex thigh grafts as alternative forms of vascular access.

    PubMed

    Bhandari, S; Wilkinson, A; Sellars, L

    1995-11-01

    To compare the survival and complication rates of saphenous vein forearm grafts and gortex thigh grafts. Retrospective study over a twelve-year period with review of case-notes. Saphenous vein forearm grafts were constructed in 17 males and 12 females, mean age 61 years and gortex thigh grafts in 24 males and 22 females (49 grafts), mean age 49 years. Grafts were the primary form of access in 9 patients in each group. Follow-up was 45.6 and 135.2 patient years on dialysis for forearm grafts and thigh grafts respectively. One-year total survival was 89.4% (89.4% at 2 years and 71.5% at 3 years) and 84.9% (82.3% at 2 years and 70.4% at 3 years) for saphenous vein forearm grafts and gortex thigh grafts respectively. The overall complication rates were 0.22 and 0.61 per patient year on dialysis for saphenous vein forearm grafts and gortex thigh grafts respectively. Thrombosis occurred in 10% and 52%, infection in 0% and 35% and no complications in 62% and 24% of saphenous vein forearm grafts and gortex thigh grafts respectively. Both saphenous vein forearm grafts and gortex thigh grafts can provide satisfactory vascular access. The survival is similar at one year but gortex thigh grafts have a higher complication rate. PMID:8605714

  18. Plant grafting: new mechanisms, evolutionary implications.

    PubMed

    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, indicating

  19. 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.

  20. 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

  1. Predictive Value of Bronchiolitis Obliterans Syndrome Stage 0p in Chronic Graft-versus-Host Disease of the Lung

    PubMed Central

    Abedin, Sameem; Yanik, Gregory A.; Braun, Thomas; Pawarode, Attaphol; Magenau, John; Goldstein, Steven C.; Levine, John E.; Kitko, Carrie L.; Couriel, Daniel R.

    2016-01-01

    Bronchiolitis obliterans syndrome (BOS) is a significant post-transplant complication with low survival. BOS stage 0p (BOS 0p) is a parameter detected on pulmonary function tests (PFTs) after lung transplantation to identify patients at risk to develop BOS. We performed a retrospective study on 442 patients who underwent allogeneic stem cell transplant from 2007 to 2011 to evaluate whether development of BOS 0p is a risk factor in this population for BOS. Patients who met criteria for BOS 0p were significantly more likely to develop BOS (hazard ratio [HR], 3.22; P < .001). BOS 0p was significantly associated with a history of lung disease pretransplant (HR, 2.48; P =.001) and chronic graft-versus-host disease (GVHD) outside the lung post-transplant (HR, 23; P < .001). Finally, BOS 0p criteria were adequately sensitive in predicting BOS (85%), with a high negative predictive value (98%). Our findings suggest a routine PFT screening strategy with the intent of detecting BOS 0p, especially among patients with prior lung disease and who developed chronic GVHD, could suitably identify an at-risk population for the development of BOS. PMID:25687798

  2. Interleukin-22 protects intestinal stem cells from immune-mediated tissue damage and regulates sensitivity to graft vs. host disease

    PubMed Central

    Hanash, Alan M.; Dudakov, Jarrod A.; Hua, Guoqiang; O’Connor, Margaret H.; Young, Lauren F.; Singer, Natalie V.; West, Mallory L.; Jenq, Robert R.; Holland, Amanda M.; Kappel, Lucy W.; Ghosh, Arnab; Tsai, Jennifer J.; Rao, Uttam K.; Yim, Nury L.; Smith, Odette M.; Velardi, Enrico; Hawryluk, Elena; Murphy, George F.; Liu, Chen; Fouser, Lynette A.; Kolesnick, Richard; Blazar, Bruce R.; van den Brink, Marcel R.M.

    2012-01-01

    Summary Little is known about the maintenance of intestinal stem cells (ISCs) and progenitors during immune-mediated tissue damage or about the susceptibility of transplant recipients to tissue damage mediated by the donor immune system during graft vs. host disease (GVHD). We demonstrate here that deficiency of recipient-derived IL-22 increased acute GVHD tissue damage and mortality, that ISCs were eliminated during GVHD, and that ISCs as well as their downstream progenitors expressed the IL-22 receptor. Intestinal IL-22 was produced after bone marrow transplant by IL-23-responsive innate lymphoid cells (ILCs) from the transplant recipients, and intestinal IL-22 increased in response to pre-transplant conditioning. However, ILC frequency and IL-22 amounts were decreased by GVHD. Recipient IL-22 deficiency led to increased crypt apoptosis, depletion of ISCs, and loss of epithelial integrity. Our findings reveal IL-22 as a critical regulator of tissue sensitivity to GVHD and a protective factor for ISC during inflammatory intestinal damage. PMID:22921121

  3. 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

  4. POST CORONARY ARTERY BYPASS GRAFT STUDY (CABG)

    EPA Science Inventory

    Relative effectiveness of moderate versus more aggressive lipid lowering, and of low dose anticoagulation versus placebo, in delaying saphenous vein coronary bypass graft atherosclerosis and preventing occlusion of saphenous grafts of patients with saphenous vein coronary bypass ...

  5. 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. PMID:26116935

  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. 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.

  8. 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

  9. 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

  10. 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.

  11. Circulating Levels of Adipokines Predict the Occurrence of Acute Graft-versus-host Disease

    PubMed Central

    Kim, Jin Sook; You, Da-Bin; Lim, Ji-Young; Lee, Sung-Eun; Kim, Yoo-Jin; Kim, Hee-Je; Min, Chang-Ki

    2015-01-01

    Currently, detecting biochemical differences before and after allogeneic stem cell transplantation (SCT) for improved prediction of acute graft-versus-host disease (aGVHD) is a major clinical challenge. In this pilot study, we analyzed the kinetics of circulating adipokine levels in patients with or without aGVHD before and after allogeneic SCT. Serum samples were obtained and stored at -80℃ within 3 hours after collection, prior to conditioning and at engraftment after transplantation. A protein array system was used to measure the levels of 7 adipokines of patients with aGVHD (n=20) and without aGVHD (n=20). The resistin level at engraftment was significantly increased (p<0.001) after transplantation, regardless of aGVHD occurrence. In the non-aGVHD group, the concentrations of the hepatocyte growth factor (HGF) (mean values±SD; 206.6±34.3 vs. 432.3±108.9 pg/ml, p=0.040) and angiopoietin-2 (ANG-2) (mean values±SD; 3,197.2±328.3 vs. 4,471.8±568.4 pg/ml, p=0.037) at engraftment were significantly higher than those of the pre-transplant period, whereas in the aGVHD group, the levels of adipokines did not change after transplantation. Our study suggests that changes in serum HGF and ANG-2 levels could be considered helpful markers for the subsequent occurrence of aGVHD. PMID:25922595

  12. Elevated Plasma Angiopoietin-2 Levels and Primary Graft Dysfunction after Lung Transplantation

    PubMed Central

    Cantu, Edward; Meyer, Nuala J.; Shah, Rupal J.; Lederer, David J.; Kawut, Steven M.; Lee, James; Bellamy, Scarlett L.; Palmer, Scott M.; Lama, Vibha N.; Bhorade, Sangeeta M.; Crespo, Maria; Demissie, Ejigayehu; Wille, Keith; Orens, Jonathan; Shah, Pali D.; Weinacker, Ann; Weill, David; Arcasoy, Selim; Wilkes, David S.; Ware, Lorraine B.; Christie, Jason D.

    2012-01-01

    Introduction Primary graft dysfunction (PGD) is a significant contributor to early morbidity and mortality after lung transplantation. Increased vascular permeability in the allograft has been identified as a possible mechanism leading to PGD. Angiopoietin-2 serves as a partial antagonist to the Tie-2 receptor and induces increased endothelial permeability. We hypothesized that elevated Ang2 levels would be associated with development of PGD. Methods We performed a case-control study, nested within the multi-center Lung Transplant Outcomes Group cohort. Plasma angiopoietin-2 levels were measured pre-transplant and 6 and 24 hours post-reperfusion. The primary outcome was development of grade 3 PGD in the first 72 hours. The association of angiopoietin-2 plasma levels and PGD was evaluated using generalized estimating equations (GEE). Results There were 40 PGD subjects and 79 non-PGD subjects included for analysis. Twenty-four PGD subjects (40%) and 47 non-PGD subjects (59%) received a transplant for the diagnosis of idiopathic pulmonary fibrosis (IPF). Among all subjects, GEE modeling identified a significant change in angiopoietin-2 level over time in cases compared to controls (p = 0.03). The association between change in angiopoietin-2 level over the perioperative time period was most significant in patients with a pre-operative diagnosis of IPF (p = 0.02); there was no statistically significant correlation between angiopoietin-2 plasma levels and the development of PGD in the subset of patients transplanted for chronic obstructive pulmonary disease (COPD) (p = 0.9). Conclusions Angiopoietin-2 levels were significantly associated with the development of PGD after lung transplantation. Further studies examining the regulation of endothelial cell permeability in the pathogenesis of PGD are indicated. PMID:23284823

  13. 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.

  14. Influence of the thymus on the capacity of female mice to reject male skin grafts

    SciTech Connect

    De Pirro, E.S.; Goldberg, E.H.

    1989-05-01

    The ability of female mice to reject H-Y-incompatible, but otherwise histocompatible, male skin grafts differs greatly from strain to strain, as is illustrated particularly by the C57BL strain (B6 and other sublines), termed ''H-Y rejector,'' because females invariably and promptly reject C57BL male skin, in comparison with the C3H strain, termed ''H-Y nonrejector,'' because females characteristically accept male C3H skin. To assess the extent to which the thymus governs this rejector vs. nonrejector status, two studies were made. In the first, lethally irradiated B6 (C57BL) and C3H females were restored with (B6 X C3H)F1 female cells, providing a graft-vs.-host-free milieu for differentiation of the same immunopoietic cell population in B6 vs. C3H hosts. With respect to (B6 X C3H)F1 male skin grafts, B6 hosts responded as rejectors and C3H hosts as nonrejectors, signifying that rejector vs. nonrejector status was determined by the host during immunopoiesis. That the main organ responsible for rejector vs. nonrejector determination is the thymus was shown in a second study. Previously thymectomized (B6 X C3H)F1 females received a histocompatible graft of thymus from either B6 or C3H neonatal females and were restored with donor-marked (B6-Ly-5a X C3H)F1 female cells after lethal irradiation. With respect to (B6 X C3H)F1 male skin grafts, the recipients of B6 thymus grafts responded generally as rejectors and the recipients of C3H thymus grafts responded uniformly as nonrejectors.

  15. Radiation graft copolymerization of butyl methacrylate and acrylamide onto low density polyethylene and polypropylene films, and its application in wastewater treatment

    NASA Astrophysics Data System (ADS)

    Abdel Ghaffar, A. M.; El-Arnaouty, M. B.; Aboulfotouh, Maysara E.; Taher, N. H.; Taha, Ahmed A.

    2014-09-01

    Butyl methacrylate and acrylamide (BMA/AAm) comonomers were grafted onto low-density polyethylene (LDPE) and polypropylene (PP) films using the mutual gamma radiation grafting technique. The influences of grafting conditions such as solvent, monomer concentration, monomer composition, and irradiation dose on the grafting yield were determined. It was found that using dimethyl formamide as a solvent enhanced the copolymerization process. The grafting yield increases as the comonomer concentration increases up to 60%. Also it was found that the degree of grafting of BMA/AAm onto both LDPE and PP films increases as the AAm content increases till an optimum value at 50:50 wt%. The grafting yield of the comonomers was found to increase with increase in the radiation dose. It was observed that the degree of grafting of polyethylene films is higher than that of polypropylene (PP) films at the same conditions. Some selected properties of the graft copolymers, such as water uptake and thermal properties, were determined using thermogravimetric analysis. The morphology and structure of the grafted films were investigated using scanning electron microscopy, infra-red, and X-ray diffraction. Improvement in such properties of the prepared copolymers was observed which offers possible uses in some practical applications such as the removal of some heavy metals from wastewater. It was found that the maximum metal uptake by the copolymer followed the order Cu2+>Co2+>Ni2+ ions.

  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. PMID:23793532

  17. Graft failure in children receiving HLA-mismatched marrow transplants with busulfan-containing regimens.

    PubMed

    Schultz, K R; Ratanatharathorn, V; Abella, E; Eisenbrey, A B; Karanes, C; Lum, L G; de Planque, M M; Uberti, J P; Ravindranath, Y; Sensenbrenner, L L

    1994-06-01

    Identifying risk factors that lead to graft failure may reduce morbidity and mortality after bone marrow transplantation (BMT) for hematologic malignancies. We evaluated engraftment of all patients with acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML) and myelodysplastic syndrome (MDS) receiving an unmanipulated marrow allogeneic BMT at the Detroit Medical Center from 1987 to 1992 using a busulfan, cyclophosphamide +/- cytarabine preparative regimen. Three of 118 patients had graft failure (2.5%; (95% confidence interval (CI) 0.7%, 6.4%). Graft failure was high in patients < or = 15 years with 3 of 12 patients with failure (25.0%) compared with 0 of 106 patients > 15 years (p = 0.002). Failure to engraft was not seen in HLA-identical (related or unrelated) donor transplants (0 of 103) whereas 3 of 15 HLA-mismatched donors failed (p = 0.003). Patient diagnosis, locus of HLA-mismatch, cytarabine in the preparative regimen, marrow cell dose and the relative reactive index (RRI) were not significant factors. Altered busulfan kinetics secondary to young age was probably not a major factor since 8 of 8 HLA-identical donor transplants engrafted in children. These findings demonstrate that patients receiving an unmanipulated marrow graft using busulfan-containing regimens were at a high risk for graft failure only if they were < or = 15 years of age and had an HLA-mismatched donor. More immunosuppressive preparative regimens, possibly including total body irradiation, should be considered to prevent potential graft failure in children. PMID:7920320

  18. Effect of MMA-g-UHMWPE grafted fiber on mechanical properties of acrylic bone cement.

    PubMed

    Yang, J M; Huang, P Y; Yang, M C; Lo, S K

    1997-01-01

    Ultrahigh molecular weight polyethylene (UHMWPE) fibers were treated with argon plasma for 5 min, followed by uv irradiation in methyl methacrylate (MMA)-chloroform solution for 5 h to obtain MMA-g-UHMWPE grafted fiber. The grafting content was estimated by the titration of esterification method. The grafting amount of 5280 nmol/g was the largest for the MMA concentration at 18.75 vol%. To improve the mechanical properties of acrylic bone cement, pure UHMWPE fiber and MMA-g-UHMWPE fiber were added to the surgical Simplex. P radiopaque bone cement. The mechanical properties including tensile strength, tensile modulus, compressive strength, bending strength, and bending stiffness were measured. Dynamic mechanical analysis was also performed. By comparing the effect of the pure UHMWPE fiber and MMA-g-UHMWPE grafted fiber on the mechanical properties of acrylic bone cement, it was found that the acrylic bone cement with MMA-g-UHMWPE grafted fiber had a more significant reinforcing effect than that with untreated UHMWPE fiber. This might be due to the improvement of the interfacial bonding between the grafted fibers and the acrylic bone cement matrix. PMID:9421758

  19. 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

  20. 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.

  1. Rapid Microwave-Assisted Grafting of Layered Perovskites with n-Alcohols.

    PubMed

    Boykin, Joshua R; Smith, Luis J

    2015-05-01

    Dion-Jacobson layered niobates have been extensively researched in recent years because of a variety of useful properties such as dielectric behavior, proton conduction, and solid acid catalysis. The behavior of these materials is strongly dependent on the elemental composition and, more specifically, the interlayer surface environment. A novel method of partial grafting of n-alcohols into the interlayer of HSr2Nb3O10 with approximately 40% conversion has been developed using microwave irradiation to generate high temperatures. This method has reduced the grafting reaction time by more than 97% while maintaining conversion rates consistent with previous methods. PMID:25906189

  2. Morbid obesity in liver transplant recipients adversely affects longterm graft and patient survival in a single-institution analysis

    PubMed Central

    Conzen, Kendra D; Vachharajani, Neeta; Collins, Kelly M; Anderson, Christopher D; Lin, Yiing; Wellen, Jason R; Shenoy, Surendra; Lowell, Jeffrey A; Doyle, M B Majella; Chapman, William C

    2015-01-01

    Objective The effects of obesity in liver transplantation remain controversial. Earlier institutional data demonstrated no significant difference in postoperative complications or 1-year mortality. This study was conducted to test the hypothesis that obesity alone has minimal effect on longterm graft and overall survival. Methods A retrospective, single-institution analysis of outcomes in patients submitted to primary adult orthotopic liver transplantation was conducted using data for the period from 1 January 2002 to 31 December 2012. Recipients were divided into six groups by pre-transplant body mass index (BMI), comprising those with BMIs of <18.0 kg/m2, 18.0–24.9 kg/m2, 25.0–29.9 kg/m2, 30.0–35.0 kg/m2, 35.1–40.0 kg/m2 and >40 kg/m2, respectively. Pre- and post-transplant parameters were compared. A P-value of <0.05 was considered to indicate statistical significance. Independent predictors of patient and graft survival were determined using multivariate analysis. Results A total of 785 patients met the study inclusion criteria. A BMI of >35 kg/m2 was associated with non-alcoholic steatohepatitis (NASH) cirrhosis (P < 0.0001), higher Model for End-stage Liver Disease (MELD) score, and longer wait times for transplant (P = 0.002). There were no differences in operative time, intensive care unit or hospital length of stay, or perioperative complications. Graft and patient survival at intervals up to 3 years were similar between groups. Compared with non-obese recipients, recipients with a BMI of >40 kg/m2 showed significantly reduced 5-year graft (49.0% versus 75.8%; P < 0.02) and patient (51.3% versus 78.8%; P < 0.01) survival. Conclusions Obesity increasingly impacts outcomes in liver transplantation. Although the present data are limited by the fact that they were sourced from a single institution, they suggest that morbid obesity adversely affects longterm outcomes despite providing similar short-term results. Further analysis is

  3. Synthesis of arsenic graft adsorbents in pilot scale

    NASA Astrophysics Data System (ADS)

    Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya; Aketagawa, Yasushi; Takahashi, Makikatsu; Yoshii, Akihiro; Tsunoda, Yasuhiko; Seko, Noriaki

    2012-08-01

    Synthesis of arsenic (As) adsorbents in pilot scale was carried out with a synthesizing apparatus by radiation-induced graft polymerization of 2-hydroxyethyl methacrylate phosphoric acid monomer (PA), which consists of phosphoric acid mono- (50%) and di- (50%) ethyl methacrylate esters onto a nonwoven cotton fabric (NCF), and following chemical modification by contact with a zirconium (Zr) solution. The apparatus which was equipped with reaction tanks, a washing tank and a pump can produce up to 0.3 m×14 m size of the As(V) adsorbent in one reaction. A degree of grafting of 150% was obtained at an irradiation dose of 20 kGy with 5% of PA solution mixed with deionized water for 1 h at 40 °C. Finally, after Zr(IV) was loaded onto a NCF with 5 mmol/L of Zr(IV) solution, the graft adsorbent for the removal of As(V) was achieved in pilot-scale. The adsorbent which was synthesized in pilot scale was evaluated in batch mode adsorption with 1 ppm (mg/l) of As(V) solution for 2 h at room temperature. As a result, the adsorption capacity for As(V) was 0.02 mmol/g-adsorbent.

  4. An update on coronary bypass graft intervention

    PubMed Central

    Dash, Debabrata

    2014-01-01

    Coronary artery bypass grafting (CABG) remains one of the most common surgical procedures. In spite of great advancements like arterial grafts and off-pump bypass procedure, recurrent ischaemia may ensue with the lesions of the graft. Early postoperative ischaemia (<30 days) is due to graft occlusion or stenosis, and percutaneous coronary intervention (PCI) is frequently feasible. Late postoperative ischaemia (>3 years) is most often due to a saphenous vein graft (SVG) lesion. Multiple diseased grafts, reduced left ventricular function, and available arterial conduits favour repeat CABG, whereas, a patent left internal mammary artery to left anterior descending favours PCI. Embolic protection reduces atheroembolic myocardial infarction during PCI of SVG and should be routinely used in treatment of SVG lesions. A variety of vasodilators may reduce the risk of or mitigate the consequences of no-reflow. Drug-eluting stents reduce restenosis in SVG grafts, and have become the default strategy for many interventionalists. PMID:27326165

  5. The use of radiation-induced graft polymerization for modification of polymer track membranes

    NASA Astrophysics Data System (ADS)

    Shtanko, N. I.; Kabanov, V. Ya.; Apel, P. Yu.; Yoshida, M.

    1999-05-01

    Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called "intelligent" materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 μm and pore density of 10 6 cm -2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl 2) and then exposed to the γ-rays from a 60Co source. The transport properties of the grafted

  6. Biology of polypropylene/polyglactin 910 grafts.

    PubMed

    Barbolt, Thomas A

    2006-06-01

    The biological evaluation of polypropylene (PP)/polyglactin 910 grafts was reviewed including regulatory considerations, biocompatibility assessment, tissue reaction and integration, and infection potentiation of these synthetic materials used in urogynecological surgical procedures. The physical characteristics of the grafts including base composition, monofilament vs multifilament, and non-absorbable vs absorbable materials were compared. Grafts were implanted in rats to evaluate the tissue reaction and integration characteristics of the materials over time. Grafts were also implanted in mice and inoculated with Staphylococcus aureus to assess the potential for bacterial attachment and growth. The tissue reaction to PP/polyglactin 910 grafts was characterized by minimal to mild inflammation with some qualitative differences related to the physical construction of the different grafts. The tissue reaction to polyglactin 910 mesh was also mild but resolved after the material was absorbed 70 days post-implantation. The integration of PP/polyglactin 910 grafts by fibrosis with surrounding tissue was initially mild for all materials but decreased over time for the lightweight and multifilament PP-based grafts, including a graft with an absorbable polyglactin 910 component. Residual fibrosis was not observed for the graft constructed from polyglactin 910 alone. Grafts constructed from PP did not potentiate infection after inoculation with S. aureus whereas the number of bacteria recovered from naturally derived collagen-based materials increased by three to four logs. The biological performance of PP/polyglactin 910 grafts is dependent on multiple factors including the composition and physical construction of the base materials, the overall biocompatibility of the materials, particularly tissue reaction and integration of the grafts, and the resistance of the grafts to bacterial attachment and growth. PMID:16738744

  7. Graft rejection after hematopoietic cell transplantation with nonmyeloablative conditioning.

    PubMed

    Masmas, Tania N; Petersen, Søren L; Madsen, Hans O; Ryder, Lars P; Kornblit, Brian; Svejgaard, Arne; Andersen, Pernille; Dickmeiss, Ebbe; Vindeløv, Lars L

    2008-07-01

    Graft rejection after hematopoietic cell transplantation (HCT) with nonmyeloablative conditioning is a rare but serious clinical problem. Graft rejection and salvage therapy in eight patients in a retrospective analysis of 124 consecutive patients is reported. The patients were conditioned with low-dose fludarabine and total body irradiation (TBI). The association of pretransplantation risk factors with rejection and the effect of chimerism and graft-versus-host disease on rejection were analyzed. Overall survival (OS) and progression free survival (PFS) were compared between patients with and without rejection. Retransplantation was performed with increased TBI conditioning for all patients, and with increased mycophenolate mofetil doses for recipients with HLA-identical sibling donors. No known pretransplantation risk factors were confirmed in this study. Rejection episodes were unevenly distributed over time. The storage temperature of the apheresis products was identified as a risk factor for rejection. Storage of the apheresis products at 5 degrees C diminished the risk of rejection. Low donor T cell chimerism at Day +14 significantly increased the risk of rejection. Seven patients were retransplanted. All but one engrafted successfully, but with decreased OS and PFS. Two patients received pentostatin infusion prior to donor lymphocyte infusions in unsuccessful attempts at reversing rejection. Storage temperature and donor chimerism had a significant effect on rejection. Following rejection, patients are at greater risk of dying from infections and progression/relapse of their malignancy. Retransplantation is feasible and well tolerated after HCT with nonmyeloablative conditioning and should be performed without delay in patients with imminent and manifest graft rejection. PMID:18383319

  8. 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.

  9. 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.

  10. Vein graft in stapes surgery.

    PubMed

    Kamal, S A

    1996-03-01

    Sealing the opening of the oval window during stapes surgery is essential; it prevents postoperative complications, such as perilymph fistula and sensorineural hearing loss. In this small series of 269 cases with otosclerosis, tympanosclerosis, and congenital ossicular abnormality, vein grafting was used to seal the opening of the footplate. Hearing improvement after surgery was acceptable, and none had total hearing loss or perilymphatic fistula. World literature from the last half of this century on grafting the oval window is reviewed. Absorbable gelatin sponge (Gelfoam) seems to be causing more complications, so its use is highly discouraged. Temporalis fascia, fat, and perivenous loose areolar tissue have been used by different authors at different times in footplate surgery. The opening created in the oval window during stapes surgery must not be left uncovered. PMID:8723953

  11. Pretransfusion blood irradiation: Clinical rationale and dosimetric considerations

    SciTech Connect

    Masterson, M.E.; Febo, R. )

    1992-05-01

    The irradiation of blood before transfusion into immunosuppressed patients is an increasingly common technique used to prevent graft-versus-host disease. A technical procedure is described for the calibration of blood irradiators, including the determination of absolute dose rate and relative dose distribution over the blood volume. Results of dose rate measurements on commercially available irradiators indicate differences of +5% to {minus}13% with manufacturer-supplied calibrations and variations in the relative dose rate over the irradiation volume from 70% to 180%. The clinical implications of these findings and the need for accurate dosimetry are discussed.

  12. Practical dosimetric aspects of blood and blood product irradiation

    SciTech Connect

    Fearon, T.C.; Luban, N.L.

    1986-09-01

    The method of choice to reduce susceptibility to transfusion-transmitted graft-versus-host disease is irradiation of allogenic blood and blood products for transfusion to immunosuppressed recipients. Optimal irradiation requires delivery of a known and homogeneous absorbed dose. The use of absorbed dose in air measured at the center of the irradiation volume without proper compensation for sample absorption can lead to approximately 20 percent underexposure. A lucite cylinder was used to provide the delivery of a homogeneous irradiation dose to blood products of different volumes by allowing rotation of the product.

  13. A study of irradiation in the treatment of wastewater

    NASA Astrophysics Data System (ADS)

    Bao, Huaying; Liu, Yuanxia; Jia, Haishun

    2002-03-01

    A grafting copolymer of starch and acrylamide was prepared by 60Co- γ pre-irradiation. After purification, the copolymer was modified by a cationic reaction to form a cationic copolymer. The structure of the cationic copolymer was identified by IR and NMR spectroscopy. Using the industrial and sanitary municipal wastewater from the Factory of Wastewater Treatment of Gaobeidian in Beijing as the study sample, three-treatment methods: flocculation deposition, flocculation deposition combined with γ irradiation and the direct irradiation were carried out. COD was applied to evaluate the treatment effect. The preliminary results show that the method of flocculation deposition combined with γ irradiation was effective than the other two.

  14. Microwave induced synthesis of graft copolymer of binary vinyl monomer mixtures onto delignified Grewia optiva fibre: Application in dye removal

    NASA Astrophysics Data System (ADS)

    Gupta, Vinod; Pathania, Deepak; Priya, Bhanu; Singha, A. K.; Sharma, Gaurav

    2014-08-01

    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 fibre were subjected to evaluation of physicochemical properties such as swelling behaviour 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 fibre 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.

  15. 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

  16. Temperature-responsiveness and biocompatibility of DEGMA/OEGMA radiation-grafted onto PP and LDPE films

    NASA Astrophysics Data System (ADS)

    Ramírez-Jiménez, Alejandro; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Bucio, Emilio

    2014-06-01

    Polypropylene (PP) and low density polyethylene (LDPE) were modified by γ-ray grafting of di(ethylene glycol) methyl ether methacrylate (DEGMA) and oligo (ethylene glycol) methyl ether methacrylate (OEGMA300 or OEGMA475 with Mn 300 and 475 respectively) with different monomer concentrations and mol ratios. The grafting percentage was evaluated as a function of the solvent, irradiation dose, reaction time, temperature, and monomers concentration. The grafted materials were more hydrophilic than the pristine polymers, as observed by contact angle and swelling in water. Temperature-responsive behavior was evaluated using DSC showing transitions between 34 and 48 °C. In vitro hemocompatibility, protein adsorption, cytotoxicity and bacteria adhesion tests were also carried out. Overall, the DEGMA/OEGMA grafting provides hemo and cytocompatible materials that exhibit temperature-responsive hydrophilic features and decreased protein adsorption.

  17. Vascularized bone graft for scaphoid nonunions.

    PubMed

    Mih, Alexander D

    2004-09-01

    Scaphoid fracture nonunion remains a challenging problem that may persist despite traditional methods of bone grafting and internal fixation. The alteration of wrist mechanics created by nonunion as well as the development of avascular necrosis leads to degenerative change of the radiocarpal joint accompanied by loss of motion and pain. The use of a vascularized bone graft has the theoretical benefit of increased blood flow that exceeds that of nonvascularized grafts. Numerous sources of vascularized bone graft have been described, including those from remote sites as well as from the carpus and distal radius. Knowledge of the blood supply to the distal radius has allowed for development of several vascularized bone graft harvest sites. The results of vascularized bone grafting from the distal radius have been encouraging, with numerous authors reporting the successful treatment of scaphoid nonunions. PMID:16518108

  18. Deformation mechanisms of electrostrictive graft elastomer

    NASA Astrophysics Data System (ADS)

    Wang, Youqi; Sun, Changjie; Zhou, Eric; Su, Ji

    2004-12-01

    The electrostrictive graft elastomer is a new type of electroactive polymer. Recently developed by NASA, it consists of flexible backbone chains, each with side chains, called grafts. Neighboring backbone grafts physically cross-link and form crystal units. The flexible backbone chain and the crystal graft unit consist of polarized monomers, which contain atoms with electric partial charges, generating dipole moments. When the elastomer is placed into an electric field, external rotating moments are applied to the dipole moment. This stimulates electrostrictive strain in the graft elastomer. In this paper, the deformation of the elastomer under the action of an electric field is explained by means of two dominant mechanisms: crystal graft unit rotation and backbone chain reorientation. A two-dimensional computational model is established to analyze the deformation.

  19. Conservative Pancreas Graft Preservation at the Extreme.

    PubMed

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

    2016-01-01

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

  20. 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

  1. 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

  2. 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.

  3. Graft compliance and anastomotic flow patterns.

    PubMed

    Wang, L C; Guo, G X; Tu, R; Hwang, N H

    1990-01-01

    The oscillatory flow patterns at the venous anastomosis of a hemodialysis angioaccess loop graft system were studied using two new compliant vascular prostheses: a longitudinally compliant polytetrafluoroethylene-composite (Baxter Ultraflex PTFE-Plus) graft (BA) and a radially compliant ultrafine polyester fiber (TORAY-UFPF) graft (TR). A non-compliant Gore-Tex polytetrafluoroethylene graft was used as the control. The experimental grafts were 8 mm inside diameter x 25 cm long. Flow experiments were done in a transparent, elastic bench-top flow model; fabrication was based on silicone rubber casts obtained from femoral-to-femoral arteriovenous loop grafts surgically implanted in dogs. The loop graft constructed in the dog model was made to mimic the branchial-to-cephalic angioaccess loop graft commonly used in hemodialysis patients. The flow model was connected to a pulse generator, an adjustable arterial afterload, and a venous afterload. Under identical input conditions, the pressure and flow waveforms were monitored simultaneously at the proximal and distal ends of both the arterial and venous anastomoses. For each graft studied, the anastomotic flow field was visualized using laser illuminated hydrogen bubbles as tracers. At pulse rates of 60 and 90 beats/min, graft flow rates were 2.2 and 2.5 L/min, respectively. Among the grafts studied, measurable differences in pressure and flow wave attenuation and their respective phase lags resulted in characteristically dissimilar flow patterns at the venous anastomosis. Growth of the separation zone at the toe of the anastomosis, and the pattern of retrograde flow in the distal vein are visibly different in all three grafts. PMID:2340213

  4. Rhinoplasty: dorsal grafts and the designer dorsum.

    PubMed

    Daniel, Rollin K

    2010-04-01

    Over the last 2 decades, many of the difficulties in shaping primary tips and rebuilding destroyed secondary tips have been solved through the use of tip sutures and grafts. Dorsal grafts, which are a highly visible determinant of the nasal profile and contour, have become the greatest challenge in rhinoplasty surgery. This article reviews the author's different approaches to dorsal grafts using fascia and diced cartilage, either separately or in combination. PMID:20206746

  5. 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.

  6. 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

  7. 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.

  8. Cellular mechanisms of tolerance after total lymphoid irradiation (TLI)

    SciTech Connect

    Strober, S.; King, D.P.; Gottlieb, M.S.; Hoppe, R.T.; Kaplan, H.S.

    1981-03-01

    In this review article on the cellular mechanisms of tolerance after total lymphoid irradiation (TLI), the effect of radiation dose and time of bone marrow infusion in mice are studied. TLI is compared to whole body irradiation with respect to the development of graft-host reaction and the number of stable chimeras obtained. The relationship between nonspecific suppressor cells and the development of tolerance after TLI is discussed. (KRM)

  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. PMID:23932643

  10. 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. PMID:24814429

  11. 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.

  12. 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.

  13. 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...

  14. Effect of bidispersity in grafted chain length on grafted chain conformations and potential of mean force between polymer grafted nanoparticles in a homopolymer matrix.

    PubMed

    Nair, Nitish; Wentzel, Nathaniel; Jayaraman, Arthi

    2011-05-21

    In efforts to produce polymeric materials with tailored physical properties, significant interest has grown around the ability to control the spatial organization of nanoparticles in polymer nanocomposites. One way to achieve controlled particle arrangement is by grafting the nanoparticle surface with polymers that are compatible with the matrix, thus manipulating the interfacial interactions between the nanoparticles and the polymer matrix. Previous work has shown that the molecular weight of the grafted polymer, both at high grafting density and low grafting density, plays a key role in dictating the effective inter-particle interactions in a polymer matrix. At high grafting density nanoparticles disperse (aggregate) if the graft molecular weight is higher (lower) than the matrix molecular weight. At low grafting density the longer grafts can better shield the nanoparticle surface from direct particle-particle contacts than the shorter grafts and lead to the dispersion of the grafted particles in the matrix. Despite the importance of graft molecular weight, and evidence of non-trivial effects of polydispersity of chains grafted on flat surfaces, most theoretical work on polymer grafted nanoparticles has only focused on monodisperse grafted chains. In this paper, we focus on how bidispersity in grafted chain lengths affects the grafted chain conformations and inter-particle interactions in an implicit solvent and in a dense homopolymer polymer matrix. We first present the effects of bidispersity on grafted chain conformations in a single polymer grafted particle using purely Monte Carlo (MC) simulations. This is followed by calculations of the potential of mean force (PMF) between two grafted particles in a polymer matrix using a self-consistent Polymer Reference Interaction Site Model theory-Monte Carlo simulation approach. Monte Carlo simulations of a single polymer grafted particle in an implicit solvent show that in the bidisperse polymer grafted particles

  15. Graft-versus-host disease versus graft-versus-leukemia.

    PubMed

    Negrin, Robert S

    2015-01-01

    Graft-versus-host disease (GVHD) is a significant clinical problem after allogenic hematopoietic cell transplantation (HCT) associated with substantial morbidity and mortality that limits the potential utility of transplantation. Associated with GVHD is the well-recognized phenomenon of the graft-versus-leukemia (GVL) effect that results in reduced risk of disease relapse. GVL effects have been observed after treatment for a broad range of hematological malignancies. Both GVHD and GVL are the results of T cell-effector functions that frames a major question in the field of how linked are these two phenomena. A major goal of basic science and translational research has been to develop strategies to reduce the risk of GVHD while maintaining or enhancing GVL. In this review, a number of different strategies developed from preclinical animal models will be explored with a focus on those approaches that have been extended to the clinic in an attempt to achieve this goal. Needless to say, there is no proven strategy; however, with the use of modern technology and clinical translation, there has been substantial progress toward this goal of reducing the risks of GVHD while promoting and enhancing GVL responses. PMID:26637726

  16. 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

  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. 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.

  19. 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.

  20. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

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

    1998-01-27

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

  1. Graft modification strategies to improve patency of prosthetic arteriovenous grafts for hemodialysis.

    PubMed

    Moufarrej, Andrew; Tordoir, Jan; Mees, Barend

    2016-03-01

    Prosthetic arteriovenous grafts (AVGs) are indicated for vascular access for long-term hemodialysis in patients in whom creation or maintenance of an arteriovenous fistula (AVF) has failed or is contraindicated. AVGs have an inferior long-term patency as compared to AVFs. To ameliorate patency rates of prosthetic AVGs, different strategies have emerged to improve graft materials. This review aims to describe current strategies and future perspectives on graft modification, by graft geometry, drug coatings and graft surface technology, to improve AVG patency. PMID:26951913

  2. 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.

  3. 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.

  4. [Autologous Fat Grafting in Scar Revision].

    PubMed

    Yu, Pan-xi; Cai, Jing-long

    2016-04-01

    Regenerative medicine is an emerging discipline. Adipose tissue is a rich source of fat cells and mesenchymal stem cells, and autologous fat grafting has increasingly been applied in plastic surgeries and dermatological treatments. This paper reviews the latest advances in autologous fat grafting in scar revision. PMID:27181904

  5. Economics of grafted vs conventional watermelon plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grafting of watermelons has been used in many countries to provide control of, or resistance to, certain soil borne diseases such as Fusarium wilt. The impact of grafting on postharvest quality has not been thoroughly examined. This report deals with the comparison of the costs of production betwe...

  6. 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.

  7. Emerging concepts in liver graft preservation

    PubMed Central

    Bejaoui, Mohamed; Pantazi, Eirini; Folch-Puy, Emma; Baptista, Pedro M; García-Gil, Agustín; Adam, René; Roselló-Catafau, Joan

    2015-01-01

    The urgent need to expand the donor pool in order to attend to the growing demand for liver transplantation has obliged physicians to consider the use of suboptimal liver grafts and also to redefine the preservation strategies. This review examines the different methods of liver graft preservation, focusing on the latest advances in both static cold storage and machine perfusion (MP). The new strategies for static cold storage are mainly designed to increase the fatty liver graft preservation via the supplementation of commercial organ preservation solutions with additives. In this paper we stress the importance of carrying out effective graft washout after static cold preservation, and present a detailed discussion of the future perspectives for dynamic graft preservation using MP at different temperatures (hypothermia at 4 °C, normothermia at 37 °C and subnormothermia at 20 °C-25 °C). Finally, we highlight some emerging applications of regenerative medicine in liver graft preservation. In conclusion, this review discusses the “state of the art” and future perspectives in static and dynamic liver graft preservation in order to improve graft viability. PMID:25593455

  8. Radiation graft modification of EPDM rubber

    NASA Astrophysics Data System (ADS)

    Katbab, A. A.; Burford, R. P.; Garnett, J. L.

    N-Vinyl pyrrolidone (NVP), 2-hydroxyethylmethacrylate (HEMA) and acrylamide (AAm) have been grafted to the surface of rubber vulcanizates based on ethylene-propylene-terpolymer (EPDM) using the simultaneous radiation method to alter surface properties such as wettability and therefore biocompatibility. The effect of monomer concentration, solvent and EPDM structural factors on the grafting behavior have been investigated. The inhibitory effect upon homopolymerization of various salts has also been evaluated for the three monomers. NVP and HEMA could be grafted onto EPDM rubber in the presence of aqueous solutions of cupric nitrate at 0.005 M and 1.0 M concentrations respectively. Aqueous solutions of Mohr's salt (ammonium ferrous sulphate) at 0.05 M not only suppressed the homopolymerization of AAm but also increased grafting yield. The percentage grafting also increased with increasing AAm concentration. A mechanism has been proposed to explain the behaviour of these monomers. The inclusion of multifunctional acrylates in additive amounts (1.0 vol%) enhanced the graft degree. Modified samples were able to be efficiently stained, allowing the depth of the graft copolymerization to be determined by light microscopy. Water was found to have an accelerating effect on the polymerization of these monomers, but methanol prevented their polymerization completely. The effect of EPDM structural factors upon degree of grafting was found to vary, depending upon the monomer type.

  9. Electrostrictive Graft Elastomers and Applications

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  10. Ex vivo lung graft perfusion.

    PubMed

    Briot, Raphaël; Gennai, Stéphane; Maignan, Maxime; Souilamas, Redha; Pison, Christophe

    2016-04-01

    This review proposes an update of the state of the art and the ongoing clinical trials of ex vivo lung perfusion for lung transplantation in patients. Ex vivo lung perfusion techniques (EVLP) can be used to evaluate a lung graft outside of the body. The goal of EVLP is to study the functional status of lung grafts that were first rejected for transplantation because they did not match all criteria for a conventional transplantation. After an EVLP evaluation, some of these lungs may be requalified for a possible transplantation in patients. This article proposes an overview of the developments of EVLP techniques. During EVLP, the perfusion and ventilation of the isolated lung preparation are very progressive in order to avoid oedema due to ischaemia-reperfusion injuries. Lung evaluation is mainly based on gasometric (PaO2/FiO2) and rheological criteria (low pulmonary arterial resistance). Several series of patients transplanted with EVLP evaluated lungs have been recently published with promising results. EVLP preparations also allow a better understanding of the physiopathology and treatments of ischaemia-reperfusion injuries. Organ procurements from "non-heart-beating" donors will probably require a wider application of these ex vivo techniques. The development of semi-automated systems might facilitate the clinical use of EVLP techniques. PMID:26746565

  11. Spreader Grafts in Functional Rhinoplasty.

    PubMed

    Kim, Leslie; Papel, Ira D

    2016-02-01

    Management of the middle vault is paramount to achieving optimal aesthetic and functional outcomes in rhinoplasty. The ideal treatment for middle vault complications, such as internal nasal valve collapse, inverted-V deformity, and middle vault dorsal asymmetry, is prevention. Risk factors for middle vault problems in rhinoplasty that may be identified in preoperative consultation include short nasal bones, long and weak upper lateral cartilages, thin skin, previous trauma or surgery, preoperative positive Cottle maneuver, tension nose deformity, and anteriorly positioned inferior turbinates. When any of these risk factors are identified, preventive measures should be pursued. These include preservation of middle vault support structures, judicious resection in dorsal hump reduction, use of conservative osteotomies, and reconstruction of the cartilaginous middle vault with structural grafting. Spreader grafts have become the workhorse in middle vault reconstruction. They are invaluable in restoring nasal dorsal aesthetic lines, repairing or maintaining the internal nasal valve, and buttressing a corrected crooked nose. Functional and aesthetic problems related to the middle nasal vault are among the most common reasons for patients seeking revision rhinoplasty. Although complications in rhinoplasty are inevitable, underlying their etiology and instituting prophylactic treatment can significantly help reduce their occurrence. PMID:26862961

  12. 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).

  13. Skin graft storage and keratinocyte viability.

    PubMed

    Fahmy, F S; Navsaria, H A; Frame, J D; Jones, C R; Leigh, I M

    1993-06-01

    The viability of human split skin grafts stored in four solutions has been assessed by monitoring the percentage of viable keratinocytes in the stored grafts. Skin grafts stored in RM+ (Ready Mix) tissue culture medium remained more viable than those stored in Hartmann's, Marshall's or saline solutions. By day 10 (postoperative), the percentage of viable keratinocytes of those grafts stored in RM+ was around 85%, compared to a value of around 10% for the other media. By day 30, RM+ achieved a value of around 60% keratinocyte viability compared to a value approaching 1% in the other storage media under investigation. RM+ provides mitogens, nutrients, growth factors and physiological pH, all of which are important factors for successful skin graft storage. PMID:8330085

  14. Recovery of antibody production in human allogeneic marrow graft recipients: influence of time posttransplantation, the presence or absence of chronic graft-versus-host disease, and antithymocyte globulin treatment.

    PubMed

    Witherspoon, R P; Storb, R; Ochs, H D; Fluornoy, N; Kopecky, K J; Sullivan, K M; Deeg, J H; Sosa, R; Noel, D R; Atkinson, K; Thomas, E D

    1981-08-01

    One-hundred fifty-three recipients of HLA-identical sibling marrow transplants for aplastic anemia or hematologic malignancy were injected with bacteriophage phi X174 (phage), pneumococcal polysaccharide antigen (PPA), or keyhole limpet hemocyanin (KLH). Antibody levels were determined several times in the 6 wk after injection. Multiple regression techniques were used to determine what factors played significant roles in the antibody response. The most significant factors were the time elapsed from transplantation, chronic graft-versus-host disease (GVHD), and antithymocyte globulin (ATG) treatment. All patients had low antibody responses to all antigens in the first 180 days from transplant. Beyond 180 days patients without chronic GVHD showed antibody responses indistinguishable from those of normal donors. However, patients with chronic GVHD had the following impairments: (1) primary response to phage, (2) conversion from IgM to IgG in secondary response to phage, (3) secondary response to KLH, and (4) response to PPA. ATG treatment given to patients either prophylactically or therapeutically for acute GVHD was followed by lower primary responses to phage in the first 180 days and poor ability to switch from IgM to IgG antibody in the secondary response beyond 180 days postgrafting. Other factors did not yield additional significant information about ability to predict antibody responses including diagnosis, conditioning regimen, treatment in or out of laminar air flow rooms, transplantation, pretransplant refractoriness of the recipient to platelet transfusions from random donors, donor age or donor sex, and steroid administration for treatment for prevention of GVHD. The data indicate that, given enough time after transplantation, the ability to produce normal antibody function recovers except in those patients experiencing chronic GVHD. PMID:6454452

  15. Historical and modern genetics of plant graft hybridization.

    PubMed

    Liu, Yongsheng

    2006-01-01

    Graft hybridization is a type of asexual hybridization in which heritable changes may be induced by grafting. Darwin was the first to put forward the conception of graft hybridization. The existence of graft hybrids has been extensively documented, although there has been a refusal to accept its reality, other than perceiving the phenomenon as involving "simple" chimeras. Graft hybrids can be divided into two categories--chimera graft hybrid (so-called graft chimera) and nonchimera graft hybrid (so-called vegetative hybrid). These differ with respect to grafting methods, characteristics, and mechanisms proposed to underlie the two categories. Graft hybridization is not only a simple and powerful means of plant breeding but also provides striking evidence in favor of Darwin's notions about Pangenesis--a developmental theory of heredity, on the one hand, and a phenomenon that plays a crucial role in revealing the mystery of non-Mendelian inheritance in grafted fruit trees. PMID:16735156

  16. [Food irradiation].

    PubMed

    Migdał, W

    1995-01-01

    A worldwide standard on food irradiation was adopted in 1983 by Codex Alimentarius Commission of the Joint Food Standard Programme of the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO). As a result, 41 countries have approved the use of irradiation for treating one or more food items and the number is increasing. Generally, irradiation is used to: food loses, food spoilage, disinfestation, safety and hygiene. The number of countries which use irradiation for processing food for commercial purposes has been increasing steadily from 19 in 1987 to 33 today. In the frames of the national programme on the application of irradiation for food preservation and hygienization an experimental plant for electron beam processing has been established in Institute of Nuclear Chemistry and Technology. The plant is equipped with a small research accelerator Pilot (19MeV, 1 kW) and an industrial unit Elektronika (10MeV, 10 kW). On the basis of the research there were performed at different scientific institutions in Poland, health authorities have issued permission for irradiation for: spices, garlic, onions, mushrooms, potatoes, dry mushrooms and vegetables. PMID:8619113

  17. 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.

  18. 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

  19. Sterilisation of canine anterior cruciate allografts by gamma irradiation in argon. Mechanical and neurohistological properties retained one year after transplantation.

    PubMed

    Goertzen, M J; Clahsen, H; Bürrig, K F; Schulitz, K P

    1995-03-01

    Bone-ACL-bone allograft transplantation is a potential solution to the problem of reconstruction of the anterior cruciate ligament (ACL), but sterilisation by gamma irradiation or ethylene oxide causes degradation of the graft. We have studied the biomechanical and histological properties of deep-frozen canine bone-ACL-bone allografts sterilised by gamma irradiation (2.5 Mrad) under argon gas protection. Particular attention was paid to their collagen structure and neuroanatomy compared with those of non-irradiated allografts. We used 60 skeletally mature foxhounds. In 30 animals one ACL was replaced by an irradiated allograft and in the other 30 a non-irradiated graft was used. In both groups the graft was augmented by a Kennedy Ligament Augmentation Device. Examination of the allografts at 3, 6 and 12 months after implantation included mechanical testing, histology, collagen morphometry, neuroanatomical morphology (silver and gold chloride stain) and studies of the microvasculature (modified Spalteholz technique). At 12 months the irradiated ACL allografts failed at a mean maximum load of 718.3 N, 63.8% of the strength of the normal canine ACL. The non-irradiated allografts failed at 780.1 N, 69.1% of normal. All the allografts showed a well-orientated collagen structure one year after transplantation and there was no difference between the irradiated grafts and the others. The silver staining technique demonstrated Golgi tendon organs and free nerve endings within both groups of allografts. As in the normal ACL these structures were most commonly found near the surface of the graft and at its bony attachments. At 12 months the irradiated allografts showed slight hypervascularity compared with the non-irradiated grafts.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7706332

  20. [Use of leukocyte-filtered, cytomegalovirus-antibody negative and irradiated cellular blood products].

    PubMed

    Solheim, B G; Albrechtsen, D H; Evensen, S A; Leivestad, T

    1990-01-10

    This paper presents both quality requirements and indications for use of leucocyte-filtered, cytomegalovirus antibody negative and irradiated cellular blood products at Rikshospitalet. Emphasis is placed on the use of standardized buffycoat depleted red cells or platelet concentrates for filtration, and the selection of leucocyte filters with high capacity and ease of bedside application. Leucocyte counts as low as 1-2 10(5) per unit are recommended after filtration in order to avoid HLA-antibody production. For bedside filtration, our choice was RC100 and PL100 (Pall) for red cells and platelets respectively. For laboratory use we prefer, for economic reasons, to use Sepacell R500 (Asahi) and Imugard IG500 (Terumo) for red cells and platelets respectively. Leucocyte-filtered blood products are considered indicated in all pre-transplant transfusions, in post-transplant HLA-sensitized patients, in other patients with febrile transfusion reactions, and in patients with an expected protracted platelet requirement. CMV antibody negative products are recommended for all immuno-deficient patients and pregnant women negative for CMV antibody. Irradiated blood products are used in the treatment of immuno-deficient patients receiving large amounts of blood, and in all severely immuno-compromised patients. In emergency situations where CMV antibody negative and/or irradiated blood products cannot be supplied, leucocyte filtration is suggested. PMID:2154061

  1. Influence of irradiation on stored platelets

    SciTech Connect

    Moroff, G.; George, V.M.; Siegl, A.M.; Luban, N.L.

    1986-09-01

    Platelet concentrates intended for transfusion to immunosuppressed patients are irradiated to minimize transfusion-induced graft-versus-host disease. Because few reports describe how irradiation influences stored platelets, the authors studied whether 5000 rad of gamma irradiation, the maximum dose currently used clinically, altered platelets in vitro. Platelet concentrates were stored for either 1 day or 5 days in plastic (PL 732) containers before gamma irradiation. One unit of a pair of identical platelet concentrates was irradiated; the second unit served as a control. Irradiation did not alter platelet morphology, mean platelet volume, expression of platelet-factor-3 activity, response to hypotonic stress, extent of discharge of lactate dehydrogenase, release of beta-thromboglobulin, formation of thromboxane B2, nor the ability to undergo synergistic aggregation. The lack of any substantial change was observed whether the platelet concentrates were stored initially for either 1 day or 5 days. These results suggest that stored platelets are not altered deleteriously by irradiation with 5000 rad.

  2. One-Year Patency of Valvulotomized Vein Grafts Is Similar to That of Arterial Grafts.

    PubMed

    Monsefi, Nadejda; Zierer, Andreas; Honarpisheh, Gazal; Bauer, Ralf; Kerl, Matthias; Beiras-Fernandez, Andres; Moritz, Anton

    2016-04-01

    Background Inferior vein graft patency after coronary artery bypass grafting (CABG) is attributed to various factors. Venous valves may limit flow, cause thrombus formation, and diminish diastolic backflow. The aim of our study was to compare clinical outcome and midterm patency rate of valvulotomized vein grafts and arterial grafts in patients undergoing CABG. Methods Between 2007 and 2010, valvulotomized saphenous vein segments were used to graft the right coronary artery (RCA) in 147 patients undergoing CABG with mean 2.8 ± 1 arterial and 1.5 ± 0.6 venous anastomoses. Outcome, reintervention, and reoperation were assessed after 4 ± 1.6 years. Intraoperative bypass flow rate was measured before and after valvulotomy of venous bypass grafts in 12 patients. Patency of the grafts was assessed by means of multislice computed tomography (MSCT) in 45 patients. Results A total of 102 patients underwent isolated CABG and 45 had combined procedures. In-hospital mortality was 2%. At 4 years' clinical follow-up, 95% of the patients were asymptomatic. Five patients underwent recoronary angiography because of angina pectoris. The MSCT and reangiography patency rate of all valvulotomized saphenous vein grafts was 97.1 versus 95.8% of arterial grafts 18 ± 6 months postoperatively. Intraoperative measurements showed a significant increase (+20.2 mL/min; p = 0.01) of flow in the venous bypass grafts to the RCA after valvulotomy. There were no reoperations at the latest follow-up. Conclusion Patients with valvulotomized venous grafts had good clinical outcome. The one-year patency rate of those grafts is comparable to that of arterial grafts. However, long-term results and angiography studies will be needed to strengthen these findings. PMID:25866977

  3. 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.

  4. Sepsis after autologous fat grafting.

    PubMed

    Talbot, Simon G; Parrett, Brian M; Yaremchuk, Michael J

    2010-10-01

    Autologous fat grafting is an increasingly popular technique, with numerous examples of excellent results. Adherence to key principles, including sterile technique and low-volume injection throughout layers of tissue, appears to be critical to obtaining good results. Reports of adverse outcomes are infrequent, but several case reports document both infectious and aesthetic complications. This case report represents an extreme complication, including abscess formation, life-threatening sepsis, and residual deformity. It serves as yet another reminder that early adoption of surgical procedures by those without a sound understanding of the underlying principles and techniques can have disastrous consequences. Furthermore, physicians operating on any patient must understand the potential for complications and be able to manage these appropriately when they occur. PMID:20885205

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

    PubMed

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

    2010-02-01

    Grafting of dopamine-rich tissue to counteract the symptoms in Parkinson's disease became a promising tool for future treatment. This article discusses how to improve the functional outcome with respect to graft outgrowth and functions of dopamine release and electrophysiological responses to graft implantation in the host brain striatal target. It has been documented that a subpopulation of the dopamine neurons innervates the host brain in a target-specific manner, while some of the grafted dopamine neurons never project to the host striatum. Neurochemical studies have demonstrated that the graft-induced outgrowth synthesize, store, metabolize and release dopamine and possibly other neurotransmitters such as 5-HT. Furthermore, the released dopamine affects the dopamine-depleted brain in areas that are larger than the graft-derived nerve fibers reach. While stem cells will most likely be the future source of cells to be used in grafting, it is important to find the guiding cues for how to reinnervate the dopamine-depleted striatum in a proper way with respect to the dopamine subpopulations of A9 and A10 to efficiently treat the motor abnormalities seen in Parkinson's disease. PMID:19853009

  6. 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.

  7. [How to handle unexpected biological abnormalities observed in the pre-donation workup for hematopoietic stem cell transplantation: an SFGM-TC report on pre-transplant cytomegalovirus, Epstein-Barr virus, Toxoplasma gondii, or syphilis IgM positive serology test].

    PubMed

    Duléry, R; Giraud, C; Beaumont, J-L; Bilger, K; Borel, C; Dhedin, N; Thiebaut, A; Willems, E; Alain, S; Alfandari, S; Dewilde, A; Jouet, J-P; Milpied, N; Yakoub-Agha, I

    2013-08-01

    In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the third annual series of workshops which brought together practitioners from all member centers and took place in October 2012 in Lille. Here we report our results and recommendations regarding the management of pre-transplant donor's cytomegalovirus, Epstein-Barr virus, Toxoplasma gondii, or syphilis IgM positive serology test. PMID:24011960

  8. Effects of sterilization and storage on the properties of ALP-grafted biomaterials for prosthetic and bone tissue engineering applications.

    PubMed

    Ferraris, S; Pan, G; Cassinelli, C; Mazzucco, L; Vernè, E; Spriano, S

    2012-10-01

    Grafting of the biomaterial surfaces with biomolecules is nowadays a challenging research field for prosthetic and bone tissue engineering applications. On the other hand, very few research works investigate the effect of the sterilization processes on the properties of functionalized biomaterials. In this study, the effects of different sterilization techniques (e.g. gamma and electron beam irradiation, ethylene oxide) on the enzymatic activity of bioactive glasses and Ti6Al4V grafted with alkaline phosphatase (ALP) have been analyzed. Sterility maintenance and in vitro bioactivity of the sterilized surfaces have also been investigated. Finally the effect of packaging and storage conditions has been considered. PMID:22971978

  9. Strontium doping of bone graft extender

    PubMed Central

    2011-01-01

    Background and purpose Allografts are often used during revision hip replacement surgery for stabilization of the implant. Resorption of the allograft may exceed new bone formation, and instability of the prosthesis can develop. We investigated whether strontium could regulate the imbalance of fast resorption of allograft and slower formation of new bone, because it is both an anabolic and an anticatabolic agent. Method Strontium was added to the implant interface environment by doping a hydroxyapatite bone graft extender. 10 dogs each received 2 experimental titanium implants. The implants were inserted within a 2.7-mm concentric gap in cancellous bone. The gap was filled with 50% (v/v) allograft mixed with 50% bone graft extender. The extender either had 5% strontium doping (SrHA) or was undoped (HA). After 4 weeks, osseointegration and mechanical fixation were evaluated by histomorphometry and by push-out test. Results SrHA bone graft extender induced a 1.2-fold increase in volume of new bone, a 1.2-fold increase in allograft remaining in the gap, and a 1.4-fold increase in surface area of the bone graft extender material in contact with new bone compared to HA bone graft extender. All these increases were statistically significant. SrHA bone graft extender did not significantly improve ongrowth of bone onto the implants or improve any of the mechanical push-out parameters compared to HA bone graft extender. Interpretation Doping of the HA bone graft extender with 5% strontium increased gap healing, preserved more of the allograft in the gap, and increased the ongrowth of bone onto the bone graft extender material, but did not improve mechanical fixation. PMID:21895497

  10. Saphenous vein graft aneurysm: an incidental finding

    PubMed Central

    Rana, Omar; Greaves, Kim; Shepherd, David; Parvin, Simon; Swallow, Rosie

    2009-01-01

    Saphenous vein graft aneurysm (SVGA) is an uncommon complication of coronary artery bypass graft surgery (CABG). An 82-year-old man underwent contrast-enhanced computed tomography to investigate aorto-iliac disease. He was coincidentally noted to have an aneurysm of the saphenous vein graft to his right coronary artery. This was visualised on transthoracic echocardiography, computed tomography and coronary angiography. In the absence of symptoms and in view of high surgical risk, conservative management with anticoagulation was chosen. The patient was commenced on warfarin and remains asymptomatic. PMID:21686801

  11. 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.

  12. Saphenous vein graft aneurysm: A case report

    PubMed Central

    Gurbuz, Ahmet Seyfeddin; Ozturk, Semi; Acar, Emrah; Efe, Suleyman Cagan; Kilicgedik, Alev; Kirma, Cevat

    2016-01-01

    BACKGROUND Saphenous vein graft aneurysms (SVGAs) are rare seen issues after coronary artery bypass graft (CABG) operation which may lead to major complications including compression of adjacent structure, myocardial ischemia, rupture, and even death. CASE REPORT We report a patient with recurrent SVGA and its treatment by percutaneous intervention with a covered stent, the diagnostic and treatment procedure were based on contrast enhanced computed tomography and myocardial perfusion scintigraphy (MPS). CONCLUSION Multimodality imaging is required to demonstrate the true size and complications of the SVGA, the relationship among the adjacent structure, and to assess ischemia and size of myocardial territory supplied by the aneurysmal graft to decide treatment strategy.

  13. Modifying glass fiber surface with grafting acrylamide by UV-grafting copolymerization for preparation of glass fiber reinforced PVDF composite membrane.

    PubMed

    Luo, Nan; Zhong, Hui; Yang, Min; Yuan, Xing; Fan, Yaobo

    2016-01-01

    Experimental design and response surface methodology (RSM) were used to optimize the modification of conditions for glass surface grafting with acrylamide (AM) monomer for preparation of a glass fiber reinforced poly(vinylidene fluoride) (PVDF) composite membrane (GFRP-CM). The factors considered for experimental design were the UV (ultraviolet)-irradiation time, the concentrations of the initiator and solvent, and the kinds and concentrations of the silane coupling agent. The optimum operating conditions determined were UV-irradiation time of 25 min, an initiator concentration of 0-0.25 wt.%, solvent of N-Dimethylacetamide (DMAC), and silane coupling agent KH570 with a concentration of 7 wt.%. The obtained optimal parameters were located in the valid region and the experimental confirmation tests conducted showed good accordance between predicted and experimental values. Under these optimal conditions, the water absorption of the grafted modified glass fiber was improved from 13.6% to 23%; the tensile strength was enhanced and the peeling strength of the glass fiber reinforced PVDF composite membrane was improved by 23.7% and 32.6% with an AM concentration at 1 wt.% and 2 wt.%. The surface composition and microstructure of AM grafted glass fiber were studied via several techniques including Field Emission Scanning Electron Microscopy (FESEM), Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) and energy dispersive X-ray spectroscopy (EDX). The analysis of the EDX and FTIR-ATR results confirmed that the AM was grafted to the glass fiber successfully by detecting and proving the existence of nitrogen atoms in the GFRP-CM. PMID:26899659

  14. 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

  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 LDPE molecular structure by gamma irradiation for bioapplications

    NASA Astrophysics Data System (ADS)

    Ferreira, L. M.; Falcão, A. N.; Gil, M. H.

    2005-07-01

    The surface properties of low-density polyethylene (LDPE) can be modified by the grafting of 2-hydroxyethyl methacrylate (HEMA). This was done aiming at the production of new materials suitable for bioapplications. Samples with different monomer concentrations were prepared from LDPE particles by gamma irradiation, following different irradiation protocols, including irradiation in presence and absence of air. The samples were characterized by thermal analysis techniques (DSC and TGA) and by Fourier transform infrared spectroscopy (FTIR). The results obtained show a decrease in the crystallinity of the supporting matrix for copolymers with high yields of grafting. However, the new materials prepared maintain good structural order resulting from the protective effect of polyHEMA grafted onto LDPE backbone. These effects can improve the diffusion of other species deeper inside the matrix and increase the material hydrophilicity. The studies performed made possible the selection of experimental protocols adequate for the production of new copolymeric materials with high grafting yield. These were used in the production of new LDPE films with enhanced hydrophilic properties.

  17. 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)

  18. Use of local allograft irradiation following renal transplantation

    SciTech Connect

    Halperin, E.C.; Delmonico, F.L.; Nelson, P.W.; Shipley, W.U.; Cosimi, A.B.

    1984-07-01

    Over a 10 year period, 67 recipients of 71 renal allografts received graft irradiation following the diagnosis of rejection. The majority of kidneys were treated with a total dose of 600 rad, 150 rad per fraction, in 4 daily fractions. Fifty-three kidneys were irradiated following the failure of standard systemic immunosuppression and maximally tolerated antirejection measures to reverse an episode of acute rejection. Twenty-two (42%) of these allografts were noted to have stable (i.e. no deterioration) or improved function 1 month following the treatment with irradiation. Eleven (21%) of these allografts maintained function 1 year following transplantation. Biopsies were obtained of 41 allografts. Of the 24 renal allografts with predominantly cellular rejection, 10 (42%) had the process reversed or stabilized at 1 month following irradiation. Five (21%) of these allografts were functioning at 1 year following irradiation. Rejection was reversed or stabilized in 6 of 17 (35%) allografts at 1 month when the histologic features of renal biopsy suggested predominantly vascular rejection. Local graft irradiation has helped maintain a limited number of allografts in patients whose rejection has failed to respond to systemic immunosuppression. Irradiation may also benefit patients with ongoing rejection in whom further systemic immunosuppression is contra-indicated.

  19. 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

  20. Irradiance gradients

    SciTech Connect

    Ward, G.J. Ecole Polytechnique Federale, Lausanne ); Heckbert, P.S. . School of Computer Science Technische Hogeschool Delft . Dept. of Technical Mathematics and Informatics)

    1992-04-01

    A new method for improving the accuracy of a diffuse interreflection calculation is introduced in a ray tracing context. The information from a hemispherical sampling of the luminous environment is interpreted in a new way to predict the change in irradiance as a function of position and surface orientation. The additional computation involved is modest and the benefit is substantial. An improved interpolation of irradiance resulting from the gradient calculation produces smoother, more accurate renderings. This result is achieved through better utilization of ray samples rather than additional samples or alternate sampling strategies. Thus, the technique is applicable to a variety of global illumination algorithms that use hemicubes or Monte Carlo sampling techniques.

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

    PubMed Central

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

    2016-01-01

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

  2. Photochemical grafting of diazonium salts on metals.

    PubMed

    Busson, Mathilde; Berisha, Avni; Combellas, Catherine; Kanoufi, Frédéric; Pinson, Jean

    2011-12-21

    4-Nitrobenzenediazonium may be photochemically grafted onto gold, copper and iron under visible and UV light. Thin nanometre layers are obtained and characterized by IRRAS, electrochemistry and ellipsometry. PMID:22031299

  3. 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

  4. Skin flaps and grafts - self-care

    MedlinePlus

    ... skin infection Surgery for skin cancer Venous ulcers , pressure ulcers , or diabetic ulcers that do not heal After mastectomy or amputation Donor sites for grafts and flaps are chosen ... surgery than the wound due to newly exposed nerve endings.

  5. Fluorescent Bioactive Corrole Grafted-Chitosan Films.

    PubMed

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

    2016-04-11

    Transparent corrole grafted-chitosan films were prepared by chemical modification of chitosan with a corrole macrocycle, namely, 5,10,15-tris(pentafluorophenyl)corrole (TPFC), followed by solvent casting. The obtained films were characterized in terms of absorption spectra (UV-vis), FLIM (fluorescence lifetime imaging microscopy), structure (FTIR, XPS), thermal stability (TGA), thermomechanical properties (DMA), and antibacterial activity. The results showed that the chemical grafting of chitosan with corrole units did not affect its film-forming ability and that the grafting yield increased with the reaction time. The obtained transparent films presented fluorescence which increases with the amount of grafted corrole units. Additionally, all films showed bacteriostatic effect against S. aureus, as well as good thermomechanical properties and thermal stability. Considering these features, promising applications may be envisaged for these corrole-chitosan films, such as biosensors, bioimaging agents, and bioactive optical devices. PMID:26899016

  6. [Graft Replacement for Adult Aortic Coarctation].

    PubMed

    Fuke, Megumi; Nishimura, Kazunori; Kehara, Hiromu; Terasaki, Takamitsu; Sakaguchi, Masayuki; Takano, Tamaki

    2015-07-01

    Case 1:a 47-year-old woman who complained of sweating, finger tremor, and chest pain was diagnosed with coarctation of the aorta and hyperthyroidism. She had been diagnosed with hypertension at 25 years of age but had not undergone further examination. Graft replacement was performed without cardiopulmonary or temporary bypass. Case 2:a 30-year-old woman was diagnosed with coarctation during infertility treatment. Although health screening had revealed hypertension 8 years previously, no further assessment took place. She underwent graft replacement with partial cardiopulmonary bypass. In both cases, we conducted a clamp test to decide whether cardiopulmonary or partial bypass was necessary for graft replacement. Blood pressure discrepancy between upper and lower extremities disappeared immediately after surgery, and no ischemic complications were observed. Hypertension in young adults should prompt further scrutiny for anatomical disorders such as coarctation. A clamp test is considered helpful regarding the surgical approach to graft replacement for coarctation. PMID:26197824

  7. High-dose electron beam sterilization of soft-tissue grafts maintains significantly improved biomechanical properties compared to standard gamma treatment.

    PubMed

    Hoburg, A; Keshlaf, S; Schmidt, T; Smith, M; Gohs, U; Perka, C; Pruss, A; Scheffler, S

    2015-06-01

    Allografts have gained increasing popularity in anterior cruciate ligament (ACL) reconstruction. However, one of the major concerns regarding allografts is the possibility of disease transmission. Electron beam (Ebeam) and Gamma radiation have been proven to be successful in sterilization of medical products. In soft tissue sterilization high dosages of gamma irradiation have been shown to be detrimental to biomechanical properties of grafts. Therefore, it was the objective of this study to compare the biomechanical properties of human bone-patellar tendon-bone (BPTB) grafts after ebeam with standard gamma irradiation at medium (25 kGy) and high doses (34 kGy). We hypothesized that the biomechanical properties of Ebeam irradiated grafts would be superior to gamma irradiated grafts. Paired 10 mm-wide human BPTB grafts were harvested from 20 donors split into four groups following irradiation with either gamma or Ebeam (each n = 10): (A) Ebeam 25 kGy, (B) Gamma 25 kGy, (C) Ebeam 34 kGy (D) Gamma 34 kGy and ten non-irradiated BPTB grafts were used as controls. All grafts underwent biomechanical testing which included preconditioning (ten cycles, 0-20 N); cyclic loading (200 cycles, 20-200 N) and a load-to-failure (LTF) test. Stiffness of non-irradiated controls (199.6 ± 59.1 N/mm) and Ebeam sterilized grafts did not significantly differ (152.0 ± 37.0 N/mm; 192.8 ± 58.0 N/mm), while Gamma-irradiated grafts had significantly lower stiffness than controls at both irradiation dosages (25 kGy: 126.1 ± 45.4 N/mm; 34 kGy: 170.6 ± 58.2 N/mm) (p < 0.05). Failure loads at 25 kGy were significantly lower in the gamma group (1,009 ± 400 N), while the failure load was significantly lower in both study groups at high dose irradiation with 34 kGy (Ebeam: 1,139 ± 445 N, Gamma: 1,073 ± 617 N) compared to controls (1,741 ± 304 N) (p < 0.05). Creep was significantly larger in the gamma irradiated groups (25 kGy: 0.96 ± 1.34 mm; 34 kGy: 1.06 ± 0.58 mm) than in the Ebeam (25 k

  8. DNA nanosensor surface grafting and salt dependence

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  9. Transgene Expression Levels Determine the Immunogenicity of Transduced Hematopoietic Grafts in Partially Myeloablated Mice

    PubMed Central

    Eixarch, Herena; Gómez, Alba; Kádár, Elisabeth; George, Mónica; Martínez, Nuria; Espejo, Carmen; Pétriz, Jordi; Gimeno, Ramon; Barquinero, Jordi

    2009-01-01

    We investigated whether transgene expression levels influence the immunogenicity of transduced hematopoietic grafts upon transplantation into partially myeloablated mice. To this aim, bone marrow cells (BMCs) transduced with retroviral vectors driving green fluorescent protein (GFP) expression either at high (high-EGFP) or low levels (low-EGFP) were transplanted into congenic recipients conditioned with sublethal doses of total body irradiation (TBI) or busulfan. Virtually all recipients showed evidence of donor engraftment 4 weeks after transplantation. However, as opposed to recipients receiving low-EGFP transduced grafts, the risk of rejecting the EGFP+ cells by 30 days after transplantation was significantly higher in mice conditioned with busulfan and receiving high-EGFP transduced grafts. Anti-EGFP cellular immune responses were demonstrated in high-EGFP-treated mice conditioned with busulfan by interferon-γ (IFN-γ), enzyme-linked immunospot assay (ELISPOT), and cytotoxic T lymphocyte (CTL) assays, in contrast to that observed in mice transplanted with low-EGFP BMC. These results show for the first time that transgene expression levels can be critical for the immunogenicity of gene-modified hematopoietic grafts, especially in immunocompetent or in partially immunosuppressed recipients. These results have profound implications in vector choice and in the design of gene therapy (GT) protocols. PMID:19707185

  10. Co-grafting of antiadhesive and antimicrobial agents onto UV-micropatterned copper surfaces.

    PubMed

    Peyre, Jessie; Humblot, Vincent; Méthivier, Christophe; Berjeaud, Jean-Marc; Pradier, Claire-Marie

    2015-12-01

    Adhesion of proteins and bacteria was reduced by a factor close to one order of magnitude, and adhered bacteria were dramatically damaged on copper surfaces by grafting a PEG-modified PMMA-based (polymethyl methacrylate) copolymer together with an antimicrobial peptide. To obtain PEG and a peptide grafted together on the surface, a UV sensitive copolymer (containing PMMA, PEG and a UV sensitive reagent) was primary synthesized and deposited. After selective UV irradiation of this copolymer layer, an antimicrobial peptide, Magainin I, was grafted onto freed-polymer coated-copper surface via a spacer molecule (a mercapto carboxylic acid). The functionalization was characterized at each step by Polarization Modulation Reflection Absorption Infrared Spectroscopy (PM-RAIRS). The antiadhesive properties of the copolymer layer and antibacterial activity of the anchored Magainin I, were individually tested toward adsorption of bovine serum albumin (BSA) proteins, and against Gram positive bacteria, Listeria ivanovii, respectively. The results revealed that adhesion of both proteins and bacteria has been considerably reduced; moreover, the peptide still displays some antimicrobial activity after grafting. This work gives new ideas and perspectives to elaborate complex surface coatings where several agents are needed like for anti-biofilm or sensing applications. PMID:26613864

  11. 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.

  12. Lewy body pathology in fetal grafts.

    PubMed

    Chu, Yaping; Kordower, Jeffrey H

    2010-01-01

    Although fetal nigral transplants have been shown to survive grafting into the striatum, increased [(18)F]6-fluroro-L-3,4-dihydroxyphenylalanine ((18)F-DOPA) uptake and improved motor function in open-label assessments have failed to establish any clinical benefits in double-blind, sham-controlled studies. To understand morphological and neurochemical alterations of grafted neurons, we performed postmortem analyses on six Parkinson's disease (PD) patients who had received fetal tissue transplantation 18-19 months, 4 years, and 14 years previously. These studies revealed robust neuronal survival with normal dopaminergic phenotypes in 18-month-old grafts and decreased dopamine transporter and increased cytoplasmic alpha-synuclein in 4-year-old grafts. We also found a decline of both dopamine transporter and tyrosine hydroxylase and the formation of Lewy body-like inclusions in 14-year-old grafts, which stained positive for alpha-synuclein and ubiquitin proteins. These pathological changes suggest that PD is an ongoing process that affects grafted cells in the striatum in a manner similar to how resident dopamine neurons are affected in the substantia nigra. PMID:20146690

  13. Polypeptide Grafted Hyaluronan: Synthesis and Characterization

    SciTech Connect

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

    2010-01-01

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

  14. 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.

  15. The effects of irradiation on blood components

    SciTech Connect

    Button, L.N.; DeWolf, W.C.; Newburger, P.E.; Jacobson, M.S.; Kevy, S.V.

    1981-01-01

    The functional properties of formed elements of whole blood were studied following irradiation doses of 500 to 20,000 rads. Irradiated lymphocytes retained only 1.5 per cent of their 3H thymidine uptake after a 5,000-rad exposure and none after 7,500 rads. Red blood cells stored for 21 days and then irradiated with 5,000 rads had the same survival as nonirradiated controls. In contrast, 5,000 rads reduced platelet yields. However, transfused irradiated platelets produced the expected increases in platelet counts and controlled hemostasis in thrombocytopenic patients. After 5,000 rads, granulocytes had normal bacterial killing capacity, chemotactic mobility, and normal superoxide production after high-dose stimulation. Nitroblue tetrazolium reduction and ingestion stimulated by complement opsonized oil droplets were not diminished by 5,000- and 10,000-rad irradiation. The functional qualities of cellular blood components other than lymphocytes are not compromised by 5,000 rads. This irradiation dose may be an effective means of controlling incidence of graft-vs-host disease in immunosuppressed patients.

  16. Segmental duct-obstructed pancreas grafts versus pancreaticoduodenal grafts with enteric diversion.

    PubMed

    Martin, X; Dubernard, J M; Sanseverino, R; Melandri, M; Faure, J L; Camozzi, L; LeFrancois, N; La Rocca, E; Gelet, A

    1989-01-01

    Between January 1985 and September 1987, we performed a prospective comparative study between segmental-pancreas transplantation with duct obstruction by neoprene (n = 17) and pancreaticoduodenal transplantation with enteric diversion to a Roux-en-Y intestinal loop (n = 14). All recipients had insulin-dependent diabetes. The immunosuppressive protocol consisted of low doses of the steroids cyclosporin A and azathioprine. Mean follow-up was 16.5 mo for the enteric-diversion group and 13.5 mo for duct-obstructed groups. Two-year patient and pancreas- and kidney-graft actuarial survival rates were 92.9, 75.5, and 74.2%, respectively, in the former group and 92.3, 58.4, and 63.7%, respectively, in the latter group (NS). Five whole-organ grafts were lost (3 vascular thromboses, 1 pancreatitis, 1 rejection), and four segmental grafts were lost (2 vascular thromboses, 1 bleeding, 1 patient's death with functional graft). More surgical complications occurred in the recipients of whole-organ grafts and were often related to the intestinal anastomosis. A satisfactory blood glucose control was observed at 3 mo and 1 yr in both groups. Provocative tests showed higher and prompter insulin secretion in patients with whole-organ grafts. In patients with segmental grafts, the response was lower and delayed with a general tendency to impaired glucose tolerance. A marked hyperinsulinemia after meals was observed in whole-organ graft recipients. Slight nocturnal hyperinsulinemia was observed in both groups. At 1 yr, glycosylated hemoglobin was normal in both groups. The absence of a significant difference between the two groups, in terms of survival and graft function, and the lower surgical complication rate seen with segmental grafts have made us return to neoprene-injected segmental grafts. PMID:2642842

  17. Developments in the prevention of transfusion-associated graft-versus-host disease.

    PubMed

    Fast, Loren D

    2012-09-01

    The transfusion of blood products can result in a variety of consequences, including transfer of pathogens and the induction of immune responses, such as the almost invariably fatal transfusion-associated graft-versus-host disease (TA-GVHD). Exposure of blood products to γ-irradiation is currently the standard of care for the prevention of TA-GVHD. Regulatory, technical and clinical challenges associated with the use of γ-irradiators are driving efforts to develop alternatives. Initially, pathogen reduction methods were developed to reduce the risk of microbial transmission by blood components. Through modifications of nucleic acids, these technologies interfere with the replication of both pathogens and leucocytes. These methods have been found to be as effective as γ-irradiation in preventing T lymphocyte proliferation and TA-GVHD responses. Additional benefits of pathogen reduction protocols potentially include inhibition of antigen presentation, cytokine production and activation of lymphocytes. PMID:22734439

  18. 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

  19. NOTE: Blood irradiation with accelerator produced electron beams

    NASA Astrophysics Data System (ADS)

    Butson, M. J.; Cheung, T.; Yu, P. K. N.; Stokes, M. J.

    2000-11-01

    Blood and blood products are irradiated with gamma rays to reduce the risk of graft versus host disease (GVHD). A simple technique using electron beams produced by a medical linear accelerator has been studied to evaluate irradiation of blood and blood products. Variations in applied doses for a single field 20 MeV electron beam are measured in a phantom study. Doses have been verified with ionization chambers and commercial diode detectors. Results show that the blood product volume can be given a relatively homogeneous dose to within 6% using 20 MeV electrons without the need to rotate the blood bags or the beam entry point. The irradiation process takes approximately 6.5 minutes for 30 Gy applied dose to complete as opposed to 12 minutes for a dual field x-ray field irradiation at our centre. Electron beams can be used to satisfactorily irradiate blood and blood products in a minimal amount of time.

  20. 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

  1. 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

  2. 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. PMID:25139689

  3. Radiation grafting of styrene and acrylonitrile to cellulose and polyethylene

    NASA Astrophysics Data System (ADS)

    Hassanpour, S.

    1999-06-01

    Radiation induced graft polymerization is one of the best methods for obtaining material with new properties. In this work, radiation grafting of styrene, mixture of styrene and acrylonitrile to cellulose and polyethylene in the presence of methanol as a solvent by mutual method is discussed. At a low dose rate, high grafting yields were obtained from the two systems used, due to lesser termination of free radicals with the polymer growing radicals and recombination of primary radicals, resulting in a longer chain length of the grafted copolymer. In the system of styrene and acrylonitrile, comonomer technique was used and the styrene controlled the homopolymer formation during graft polymerization. Water uptake of cellulose decreased by increasing the grafting yields. Grafted cellulose can be molded to some extent and in a high percent of grafting, a new transparent material was obtained. By radiation grafting of styrene-acrylonitrile to low density polyethylene a high degree of crosslinking was observed.

  4. Endothelial Outgrowth Cells: Function and Performance in Vascular Grafts

    PubMed Central

    Glynn, Jeremy J.

    2014-01-01

    The clinical need for vascular grafts continues to grow. Tissue engineering strategies have been employed to develop vascular grafts for patients lacking sufficient autologous vessels for grafting. Restoring a functional endothelium on the graft lumen has been shown to greatly improve the long-term patency of small-diameter grafts. However, obtaining an autologous source of endothelial cells for in vitro endothelialization is invasive and often not a viable option. Endothelial outgrowth cells (EOCs), derived from circulating progenitor cells in peripheral blood, provide an alternative cell source for engineering an autologous endothelium. This review aims at highlighting the role of EOCs in the regulation of processes that are central to vascular graft performance. To characterize EOC performance in vascular grafts, this review identifies the characteristics of EOCs, defines functional performance criteria for EOCs in vascular grafts, and summarizes the existing work in developing vascular grafts with EOCs. PMID:24004404

  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. 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.

  7. 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.

  8. 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.

  9. Vein to artery grafts. An experimental study of reinnervation of the graft wall.

    PubMed Central

    Meagher, S; McGeachie, J; Prendergast, F

    1984-01-01

    Iliolumbar vein to iliac artery grafts were placed in 21 rats by microsurgical techniques. Graft innervation was examined at five time intervals between 1 and 32 weeks after surgery. Nerve fibers were demonstrated microscopically by formaldehyde-induced fluorescence of catecholamines. The morphology and degree of graft innervation were assessed, semiquantitatively, relative to the contralateral iliac artery (control) within each animal. Nerves were seen in the graft region as early as 2 weeks, but it was not until 4 weeks that they were present along its length (5 mm). The formation of a nerve plexus in the adventitia surrounding the graft was evident at 8 weeks. By 16 weeks the degree of innervation in the graft had increased to a level that was greater than the control iliac artery in three of four animals examined. Grafts at 32 weeks were also hyperinnervated. However, the morphology of this innervation was different from the control arteries; nerve fibers were finer, not varicosed, and were located at a greater distance from the outer layer of smooth muscle cells. The origin of the nerves appeared to be collateral sprouts from nerves supplying the adjacent iliac vein and also from invading vasa vasorum. The host iliac artery nerve plexus did not contribute to graft innervation. Images FIG. 1. PMID:6465969

  10. 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.

  11. 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 ...

  12. Improving coronary artery bypass graft durability: use of the external saphenous vein graft support.

    PubMed

    Ferrari, Enrico; von Segesser, Ludwig; Berdajs, Denis

    2015-01-01

    Coronary bypass grafting remains the best option for patients suffering from multivessel coronary artery disease, and the saphenous vein is used as an additional conduit for multiple complete revascularizations. However, the long-term vein graft durability is poor, with almost 75% of occluded grafts after 10 years. To improve the durability, the concept of an external supportive structure was successfully developed during the last years: the eSVS Mesh device (Kips Bay Medical) is an external support for vein graft made of weft-knitted nitinol wire into a tubular form with an approximate length of 24 cm and available in three diameters (3.5, 4.0 and 4.5 mm). The device is placed over the outer wall of the vein and carefully deployed to cover the full length of the graft. The mesh is flexible for full adaptability to the heart anatomy and is intended to prevent kinking and dilatation of the vein in addition to suppressing the intima hyperplasia induced by the systemic blood pressure. The device is designed to reduce the vein diameter of about 15-20% at most to prevent the vein radial expansion induced by the arterial blood pressure, and the intima hyperplasia leading to the graft failure. We describe the surgical technique for preparing the vein graft with the external saphenous vein graft support (eSVS Mesh) and we share our preliminary clinical results. PMID:25976117

  13. Branched endovascular stent–graft for suprarenal aortic aneurysm: the future of aortic stent-grafting?

    PubMed Central

    Tse, Leonard W.; Steinmetz, Oren K.; Abraham, Cherrie Z.; Valenti, David A.; MacKenzie, Kent S.; Obrand, Daniel I.; Chuter, Timothy A.

    2004-01-01

    The use of a branched endovascular stent–graft to repair an aneurysm of the visceral aorta is described. The evolving role of branched endovascular stent–grafts in the management of aortic aneurysms is discussed, and the literature reviewed. PMID:15362327

  14. 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. PMID:26457445

  15. 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.

  16. 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.

  17. A Simple Preparation of Photoactive Glass Surfaces Allowing Coatings via the "Grafting-from" Method.

    PubMed

    Sangermano, Marco; Periolatto, Monica; Castellino, Micaela; Wang, Jieping; Dietliker, Kurt; Grützmacher, Joëlle Levalois; Grützmacher, Hansjörg

    2016-08-01

    A simple and straightforward synthesis was developed to prepare the siloxy-substituted bis(acylphosphane)oxide 4-(trimethoxysilyl)butyl-3-[bis(2,4,6-trimethylbenzoyl)phosphinoyl]-2-methyl-propionate TMESI(2)-BAPO. This new photoinitiator was successfully fixed to glass surfaces. Subsequent irradiation with UV light in the presence of either a partially fluorinated acrylate or a specifically synthesized polysiloxane containing polymerizable acrylate functions allowed the generation of polymer chains which grew from the surface in an efficient radical polymerization process ("grafting-from" procedure). Durable hydrophobic surfaces were prepared which have contact angles between 93° and 95°. The silanization process with the photoinitiator and the grafting process were followed and analyzed with various techniques including high-resolution X-ray photoelectron spectroscopy. PMID:27403625

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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).

  4. 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)

  5. 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

  6. Breast reconstruction de novo by water-jet assisted autologous fat grafting – a retrospective study

    PubMed Central

    Hoppe, Delia Letizia; Ueberreiter, Klaus; Surlemont, Yves; Peltoniemi, Hilkka; Stabile, Marco; Kauhanen, Susanna

    2013-01-01

    Background: Autologous fat grafting has become a frequent, simple, reproducible and low-risk technique for revisional or partial breast reconstruction. The presented European multicenter study describes an optimized treatment and follow-up protocol for the de novo breast reconstruction after total mastectomy by lipotransfer alone. Methods: A retrospective European multicenter trial included 135 procedures on 28 (35 breasts) postmastectomy patients (mean 52.4 years). All women were treated with the water-jet assisted fat grafting method (BEAULI™) combined with additional procedures (NAC reconstruction, contralateral mastoplasty) and evaluated with at least 6 months follow-up (mean 2.6 years). Sonography or mammography, clinical examination, patient questionnaire (10-point Likert scale) and digital photographs were carried out. Results: On average the patients received 4 to 6 procedures each with a single volume of 159 ml (±61 ml) over 21 months (range 9 months to 2.5 years). In total 1,020 ml (±515 ml) fat were grafted till a complete breast reconstruction was achieved. Irradiated patients needed a significantly higher volume than non-irradiated (p<0.041). Main treatment complications were liponecrosis (2.59%), infection (0.74%) and granuloma (0.74%). Patient satisfaction was overall high to very high (96%) and confirmed the good aesthetic results (68%) and the natural softness, contour and shape of the reconstructed breast. Conclusions: A complete breast reconstruction with large volume fat grafting is alternatively possible to standard techniques in selected cases. It takes at least 4 to 6 lipotransfers in the course of 2 years. Patients with prior radiotherapy may require even up to 8 sessions over nearly 3 years of treatment. PMID:24403878

  7. Late fiber deterioration in Dacron arterial grafts.

    PubMed Central

    Berger, K; Sauvage, L R

    1981-01-01

    The occurrence of late fiber deterioration was examined in 493 Dacron arterial prostheses. Grafts implanted were of four types: 137 Meadox Wesolowski Weavenit (WN), 71 Golaski Microknit (MK), 70 USCI Sauvage(Tm) external velour non-crimped (EVNC), and 215 USCI Sauvage external velour random-crimped (EVRC). Prostheses had been implanted for three to 15.3 years; no defects were detected prior to three years. Deterioration occurred in 15 of 493 grafts (mean incidence: 3%). Between 4.9% and 5.8% of patients had graft deterioration-nearly the same incidence in all four types of grafts. Deterioration consisted of thinning and breakage of yarn filaments, causing development of holes and, in some cases, graft dilatation. Dilatation did not always precede filament breakage. Broken filament ends were either tapered or square-ended, suggesting that modes of breakage. Tensile strength tests howed that fibers sometimes weakened nonuniformly within a specimen. Fiber breakage was associated with crimp ridges. The findings suggest that manufacturing variations probably reduce fiber resistance to mechanical fatigue. Other contributing factors may include storage conditions, sterilization methods, handling, and the degradative effects of tissue fluids and enzymes. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. PMID:6452101

  8. Engineering anatomically shaped human bone grafts

    PubMed Central

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

    2009-01-01

    The ability to engineer anatomically correct pieces of viable and functional human bone would have tremendous potential for bone reconstructions after congenital defects, cancer resections, and trauma. We report that clinically sized, anatomically shaped, viable human bone grafts can be engineered by using human mesenchymal stem cells (hMSCs) and a “biomimetic” scaffold-bioreactor system. We selected the temporomandibular joint (TMJ) condylar bone as our tissue model, because of its clinical importance and the challenges associated with its complex shape. Anatomically shaped scaffolds were generated from fully decellularized trabecular bone by using digitized clinical images, seeded with hMSCs, and cultured with interstitial flow of culture medium. A bioreactor with a chamber in the exact shape of a human TMJ was designed for controllable perfusion throughout the engineered construct. By 5 weeks of cultivation, tissue growth was evidenced by the formation of confluent layers of lamellar bone (by scanning electron microscopy), markedly increased volume of mineralized matrix (by quantitative microcomputer tomography), and the formation of osteoids (histologically). Within bone grafts of this size and complexity cells were fully viable at a physiologic density, likely an important factor of graft function. Moreover, the density and architecture of bone matrix correlated with the intensity and pattern of the interstitial flow, as determined in experimental and modeling studies. This approach has potential to overcome a critical hurdle—in vitro cultivation of viable bone grafts of complex geometries—to provide patient-specific bone grafts for craniofacial and orthopedic reconstructions. PMID:19820164

  9. Grafting of oligosaccharides onto synthetic polymer colloids.

    PubMed

    Mange, Siyabonga; Dever, Cédric; De Bruyn, Hank; Gaborieau, Marianne; Castignolles, Patrice; Gilbert, Robert G

    2007-06-01

    A new method to form colloidally stable oligosaccharide-grafted synthetic polymer particles has been developed. The oligosaccharides, of weight-average degree of polymerization approximately 38, were obtained by enzymatic debranching of amylopectin. Through the use of a cerium(IV)-based redox initiation process, oligosaccharide chains are grafted onto a synthetic polymer colloid comprising electrostatically stabilized poly(methyl methacrylate) or polystyrene latex particles swollen with methyl methacrylate monomer. Ce(IV) creates a radical species on these oligosaccharides, which then propagates, initially with aqueous-phase monomer, then with the methyl methacrylate monomer inside the particles. Ultracentrifugation, NMR, and total starch analyses together prove that the grafting process has occurred, with at least 7.7 wt % starch grafted and a grafting efficiency of 33%. The surfactant used in latex preparation was removed by dialysis, resulting in particles colloidally stabilized with only linear starch as a steric stabilizer. The debranched starch that comprises these oligosaccharides is found to be a remarkably effective colloidal stabilizer, albeit at low electrolyte concentration, stabilizing particles with very sparse surface coverage. PMID:17497920

  10. 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.

  11. 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. PMID:21905884

  12. 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

  13. Evolution of complete arterial grafting. For coronary artery disease.

    PubMed Central

    Buxton, B F; Fuller, J A; Tatoulis, J

    1998-01-01

    Arterial grafting for the correction of coronary artery disease preceded the use of saphenous vein grafts, but the overwhelming popularity of the saphenous vein from 1970 to 1985 left the development of arterial grafting dormant. Excellent graft patency results from pedicled internal thoracic artery grafting and continued saphenous vein graft failure prompted our unit to explore complete arterial grafting with internal thoracic artery and radial artery grafts. One thousand and fifty-three patients who received a combination of internal thoracic artery and radial artery grafts were compared with 1,156 patients who received internal thoracic artery and saphenous vein grafts. All patients underwent primary coronary artery bypass surgery between 1995 and 1998. The early mortality and morbidity and the probability of survival at 2 years were similar in both groups of patients. Early graft patency studies of 35 radial artery grafts showed 33 (94%) were patent at a mean of 12 months. Complete arterial grafting using internal thoracic and radial arteries is safe and may provide a long-term benefit. Images PMID:9566058

  14. Preparation of polymer decorated graphene oxide by γ-ray induced graft polymerization

    NASA Astrophysics Data System (ADS)

    Zhang, Bowu; Zhang, Yujie; Peng, Cheng; Yu, Ming; Li, Linfan; Deng, Bo; Hu, Pengfei; Fan, Chunhai; Li, Jingye; Huang, Qing

    2012-02-01

    Herein, we report a facile approach to decorate graphene oxide (GO) sheets with poly(vinyl acetate) (PVAc) by γ-ray irradiation-induced graft polymerization. The content of PVAc in the obtained sample, i.e., PVAc grafted GO (GO-g-PVAc) is calculated by the loss weight in thermogravimetric analysis (TGA) curves. A GO-g-PVAc sample with a degree of grafting (DG) of 28.5% was well dispersed in common organic solvents and the dispersions obtained were extremely stable at room temperature without any aggregation, even after standing for 2 months. The excellent dispersibility and stability of GO-g-PVAc in common organic solvents are readily rationalized in terms of the full coverage of PVAc chains and solvated layer formation on graphene oxide sheets surface, which weakens the interlaminar attraction of GO sheets. This approach presents a facile route for the preparation of dispersible GO and shows great potential in the preparation of graphene-based composites by solution-processes.Herein, we report a facile approach to decorate graphene oxide (GO) sheets with poly(vinyl acetate) (PVAc) by γ-ray irradiation-induced graft polymerization. The content of PVAc in the obtained sample, i.e., PVAc grafted GO (GO-g-PVAc) is calculated by the loss weight in thermogravimetric analysis (TGA) curves. A GO-g-PVAc sample with a degree of grafting (DG) of 28.5% was well dispersed in common organic solvents and the dispersions obtained were extremely stable at room temperature without any aggregation, even after standing for 2 months. The excellent dispersibility and stability of GO-g-PVAc in common organic solvents are readily rationalized in terms of the full coverage of PVAc chains and solvated layer formation on graphene oxide sheets surface, which weakens the interlaminar attraction of GO sheets. This approach presents a facile route for the preparation of dispersible GO and shows great potential in the preparation of graphene-based composites by solution-processes. Electronic

  15. [Clinical experiences of a new vascular graft prosthesis fabricated from ultrafine polyester fiber (Toray graft)].

    PubMed

    Hashimoto, A; Aomi, S; Koyanagi, H

    1992-11-01

    A new low porous vascular prosthesis made of a textile of ultra-fine fiber was used clinically in ten patients for whom replacement of the ascending and/or arch aorta were performed. There were no operative deaths after initial operations, but one patient died after a second operation in which replacement of the thoraco-abdominal aorta was performed. Nine survived patients are well for 50 days to 10 months postoperatively. The new vascular graft prosthesis was very soft and pliable in clinical use, and the surgical needle penetrates easily the prosthesis. Although the new graft prosthesis can be used without preclotting under full heparinization, porosity of the graft, 100 ml/min/cm, revealed initial oozing of blood for a while just after releasing an aortic clamp. Therefore, preclotting of the graft is recommended under full heparinization. Because of rapid, even, and stable formation of neo-intima in the new graft confirmed by experimental studies of Noishiki et al., and soft and pliable characteristics of the graft, a wide-spread clinical use of the new graft is recommended in the surgery of aortic aneurysms as well as reconstruction of the congenital malformations. PMID:1405126

  16. Tendon graft substitutes-rotator cuff patches.

    PubMed

    Coons, David A; Alan Barber, F

    2006-09-01

    Over the past few years, many biologic patches have been developed to augment repairs of large or complex tendon tears. These patches include both allograft and xenografts. Regardless of their origins, these products are primarily composed of purified type I collagen. Many factors should be considered when choosing an augmentation patch including tissue origin, graft processing, cross-linking, clinical experience, and physical properties. The purpose of this article is to familiarize the sports medicine community with several tendon augmentation grafts: GraftJacket (Wright Medical Technology, Arlington, TN), CuffPatch (Organogenesis, Canton, MA, licensed to Arthrotek, Warsaw, IN), Restore (Depuy, Warsaw, IN), Zimmer Collagen Repair (Permacol) patch (Tissue Science Laboratories Covington, GA, licensed to Zimmer, Warsaw, IN), TissueMend (TEI Biosciences, Boston, MA, licensed to Stryker Howmedica Osteonics, Kalamazoo, MI), OrthoADAPT (Pegasus Biologics, Irvine, CA), and BioBlanket (Kensey Nash, Exton, PA). PMID:17135966

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Selective preservation of infected prosthetic arterial grafts. Analysis of a 20-year experience with 120 extracavitary-infected grafts.

    PubMed Central

    Calligaro, K D; Veith, F J; Schwartz, M L; Goldsmith, J; Savarese, R P; Dougherty, M J; DeLaurentis, D A

    1994-01-01

    OBJECTIVE: The authors report on their 20-year experience with 120 patients with infected extracavitary prosthetic arterial grafts (95 polytetraflouroethylene, 25 Dacron). Throughout this experience, an effort was made, when appropriate, to salvage all or a portion of these infected grafts. METHODS: When patients had arterial bleeding (20 cases) or systemic sepsis (6 cases), immediate graft excision was performed. When the infected graft was occluded (43 cases), subtotal graft excision was performed, leaving an oversewn 2- to 3-mm graft remnant to maintain patency of the artery. Complete graft preservation was attempted in 51 cases in which the graft was patent, the patient was not septic, and the anastomoses were intact. Aggressive operative wound debridement was repeated, as necessary, to achieve wound healing. The preferred method of revascularization, when necessary, included secondary bypasses tunneled through uninfected (often lateral) routes. Follow-up averaged 3 years (range, 1 month-20 years). RESULTS: This strategy resulted in a hospital mortality of 12% (14/120) and a hospital amputation rate in survivors of 13% (14/106 threatened limbs). Of the surviving patients treated by complete graft preservation, the hospital amputation rate was only 4% (2/45) and long-term complete graft preservation was successful in 71% (32/45) of cases. Partial graft preservation also proved successful in 85% (35/41) of surviving patients who had occluded grafts. Successful complete graft preservation was as likely when gram-negative or gram-positive bacteria were cultured from the wound, with the exception of Pseudomonas (successful graft preservation in only 40% [4/10] of cases). CONCLUSION: Based on this 20-year experience, the authors conclude that selective partial or complete graft preservation represents a simpler and better method of managing infected extracavitary prosthetic grafts than routine total graft excision. Images Figure 2. PMID:7944658

  2. 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.

  3. Microphase separation in a model graft copolymer

    SciTech Connect

    Dozier, W.D.; Thiyagarajan, P.; Peiffer, D.G.

    1993-10-01

    We present a preliminary overview of our work on a series of graft copolymers having poly(ethyl acrylate) backbones with pendant chains of polystyrene (PS). The copolymer system appeared to be in the strong segregation limit and exhibited evidence of ordered structures. The morphology of these structures can apparently be very different from what would be expected. For instance, we observed a lamellar structure in a material containing 28 wt.% PS grafts. Samples under uniaxial strain showed either conventional (i.e., affine deformation) and anomalous ({open_quotes}butterfly{close_quotes} isointensity patterns) behavior in small-angle neutron scattering.

  4. 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

  5. Pretransplant mobilization with granulocyte colony-stimulating factor improves B-cell reconstitution by lentiviral vector gene therapy in SCID-X1 mice.

    PubMed

    Huston, Marshall W; Riegman, Adriaan R A; Yadak, Rana; van Helsdingen, Yvette; de Boer, Helen; van Til, Niek P; Wagemaker, Gerard

    2014-10-01

    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

  6. 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.

  7. 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.

  8. 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.

  9. Microwave-Assisted Synthesis and Physicochemical Characterization of Tetrafuranylporphyrin-Grafted Reduced-Graphene Oxide.

    PubMed

    Bosca, Federica; Orio, Laura; Tagliapietra, Silvia; Corazzari, Ingrid; Turci, Francesco; Martina, Katia; Pastero, Linda; Cravotto, Giancarlo; Barge, Alessandro

    2016-01-26

    This work describes the design of a modified porphyrin that bears four furan rings linked by 1,2-bis-(2-aminoethoxy)ethane spacers. This unit is a well-suited scaffold for a Diels-Alder reaction with commercial reduced-graphene oxide, which is also described in this paper. A new hybrid material is obtained, thanks to efficient grafting under microwave irradiation, and fully characterized in terms of structure (UV, TGA, Raman) and morphology (HR-TEM and AFM). Potential applications in photo- and sonodynamic therapy are envisaged. PMID:26603672

  10. Laparoscopically assisted total daVinci aorto bifemoral graft bypass with a unique system of graft delivery.

    PubMed

    Martinez, B D; George, P M; Ameer, A; Gerhardinger, A M; Moses, J T; Hansen, J M

    2009-03-01

    We report the first known example of a fully robotic aortobifemoral graft and aortic endarterectomy using the daVinci Surgical System and a unique method for graft delivery using the Endo-Vein Harvester. PMID:18657387

  11. 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.

  12. 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...

  13. Diffusion and Perfusion: The Keys to Fat Grafting

    PubMed Central

    Khouri, Roger K.; Khouri, Raoul-Emil R.; Lujan-Hernandez, Jorge R.; Khouri, Khalil R.; Lancerotto, Luca

    2014-01-01

    Background: Fat grafting is now widely used in plastic surgery. Long-term graft retention can be unpredictable. Fat grafts must obtain oxygen via diffusion until neovascularization occurs, so oxygen delivery may be the overarching variable in graft retention. Methods: We studied the peer-reviewed literature to determine which aspects of a fat graft and the microenvironment surrounding a fat graft affect oxygen delivery and created 3 models relating distinct variables to oxygen delivery and graft retention. Results: Our models confirm that thin microribbons of fat maximize oxygen transport when injected into a large, compliant, well-vascularized recipient site. The “Microribbon Model” predicts that, in a typical human, fat injections larger than 0.16 cm in radius will have a region of central necrosis. Our “Fluid Accommodation Model” predicts that once grafted tissues approach a critical interstitial fluid pressure of 9 mm Hg, any additional fluid will drastically increase interstitial fluid pressure and reduce capillary perfusion and oxygen delivery. Our “External Volume Expansion Effect Model” predicts the effect of vascular changes induced by preoperative external volume expansion that allow for greater volumes of fat to be successfully grafted. Conclusions: These models confirm that initial fat grafting survival is limited by oxygen diffusion. Preoperative expansion increases oxygen diffusion capacity allowing for additional graft retention. These models provide a scientific framework for testing the current fat grafting theories. PMID:25426403

  14. 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...

  15. Iliac arterial-enteric fistulas occurring after pelvic irradiation

    SciTech Connect

    Vetto, J.T.; Culp, S.C.; Smythe, T.B.; Chang, A.E.; Sindelar, W.F.; Sugarbaker, P.H.; Heit, H.A.; Giordano, J.M.; Kozloff, L.

    1987-05-01

    Fistulas from the iliac artery to the bowel constitute a condition that is often lethal. Excluding fistulas related to vascular grafts, a review of previously reported cases shows that they are most often due to atherosclerotic iliac aneurysms. Three unusual cases of this condition that occurred after high-dose pelvic irradiation for treatment of cancer are presented; in no case was recurrent tumor evident. These cases suggest that high-dose pelvic irradiation can predispose to the formation of iliac arterial-enteric fistulas, particularly if sepsis or inflammation develops. The definitive surgical management of these fistulas entails bowel resection, arterial ligation, and extra-anatomic bypass.

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

    PubMed

    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

    2016-03-01

    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. Stem Cells 2016;34:668-673. PMID:26661694

  17. 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

  18. Graft selection strategy in adult-to-adult living donor liver transplantation: When both hemiliver grafts meet volumetric criteria.

    PubMed

    Kurihara, Takeshi; Yoshizumi, Tomoharu; Yoshida, Yoshihiro; Ikegami, Toru; Itoh, Shinji; Harimoto, Norifumi; Ninomiya, Mizuki; Uchiyama, Hideaki; Okabe, Hirohisa; Kimura, Koichi; Kawanaka, Hirofumi; Shirabe, Ken; Maehara, Yoshihiko

    2016-07-01

    To ensure donor safety in living donor liver transplantation (LDLT), the left and caudate lobe (LL) is the preferred graft choice. However, patient prognosis may still be poor even if graft volume (GV) selection criteria are met. Our aim was to evaluate the effects of right lobe (RL) donation when the LL graft selection criteria are met. Consecutive donors (n = 135) with preoperative LL graft volumetric GV/standard liver volume (SLV) of ≥35% and RL remnant of ≥35% were retrospectively studied. Patients were divided into 2 groups: LL graft and RL graft. Recipient's body surface area (BSA), Model for End-Stage Liver Disease (MELD) score, and the donor's age were higher in the RL group. The donor's BSA and preoperative volumetric GV/SLV of the LL graft were smaller in the RL group. The predicted score (calculated using data for graft size, donor age, MELD score, and the presence of portosystemic shunt, which correlated well with graft function and with 6-month graft survival) of the RL group, was significantly lower if the LL graft were used, but using the actual RL graft improved the score equal to that of the LL group. Six-month and 12-month graft survival rates did not differ between the 2 groups. In patients with a poor prognosis, a larger RL graft improved the predicted score and survival was equal to that of patients who received LL grafts. In conclusion, graft selection by GV, donor age, and recipient MELD score improves outcomes in LDLT. Liver Transplantation 22 914-922 2016 AASLD. PMID:26953726

  19. 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.

  20. 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.

  1. 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.

  2. [Cartilage vs. temporal fascia as graft material].

    PubMed

    Dost, Philipp; Maune, Steffen

    2014-08-01

    So far, comparative studies have shown no significant audiological difference between cartilage and fascia grafts. In this retrospective study, the Turkish scientists E E Callioglu et al. examined next audiological results and morphological results after surgical cartilage and fascial tympanoplasty in patients with comparable preoperative hearing and middle ear pathology. PMID:25215384

  3. 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.

  4. 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.

  5. 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...

  6. Tissue engineered small-diameter vascular grafts.

    PubMed

    Schmedlen, Rachael H; Elbjeirami, Wafa M; Gobin, Andrea S; West, Jennifer L

    2003-10-01

    Arterial occlusive disease remains the leading cause of death in western countries and often requires vascular reconstructive surgery. The limited supply of suitable small-diameter vascular grafts has led to the development of tissue engineered blood vessel substitutes. Many different approaches have been examined, including natural scaffolds containing one or more ECM proteins and degradable polymeric scaffolds. For optimal graft development, many efforts have modified the culture environment to enhance ECM synthesis and organization using bioreactors under physiologic conditions and biochemical supplements. In the past couple of decades, a great deal of progress on TEVGs has been made. Many challenges remain and are being addressed, particularly with regard to the prevention of thrombosis and the improvement of graft mechanical properties. To develop a patent TEVG that grossly resembles native tissue, required culture times in most studies exceed 8 weeks. Even with further advances in the field, TEVGs will likely not be used in emergency situations because of the time necessary to allow for cell expansion, ECM production and organization, and attainment of desired mechanical strength. Furthermore, TEVGs will probably require the use of autologous tissue to prevent an immunogenic response, unless advances in immune acceptance render allogenic and xenogenic tissue use feasible. TEVGs have not yet been subjected to clinical trials, which will determine the efficacy of such grafts in the long term. Finally, off-the-shelf availability and cost will become the biggest hurdles in the development of a feasible TEVG product. Although many obstacles exist in the effort to develop a small-diameter TEVG, the potential benefits of such an achievement are exciting. In the near future, a nonthrombogenic TEVG with sufficient mechanical strength may be developed for clinical trials. Such a graft will have the minimum characteristics of biological tissue necessary to remain patent

  7. 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.

  8. Patency rate and complications of polytetrafluoroethylene grafts compared with polyurethane grafts for hemodialysis access

    PubMed Central

    2010-01-01

    Background The survival of hemodialysis patients requiring dialysis depends on the long-term functioning and patency of the vascular access. Prosthetic vascular grafts are inevitably used for patients whose vessels are unsuitable for an autogenous arteriovenous (AV) fistula. The purpose of this study was to compare the patency rate and associated complications using different types of grafts. Methods This prospective study was conducted on patients who did not have an appropriate vein for arteriovenous fistula from January 2004 through July 2006. They were divided into two groups, sex, age, and basic data matched. Polytetrafluoroethylene (PTFE) and polyurethane (PVAG) were the two types of grafts used in this study. The functionality of the graft was assessed immediately 1 day and 2 weeks after operation. The clinical follow-up was performed each 3 months until 24 months. Results One-year patency rate was reported to be 64% and 52% in the PTFE and PVAG groups, respectively. There was no significant difference in 1-year (64% versus 52%) and 2-year (49% versus 41%) patency rate of the PTFE and PVAG grafts used as vascular access. There was also no difference between the numbers of complications reported in the two groups. Conclusion It could be concluded that either PTFE or PVAG grafts can be used with the same expected outcomes. PMID:20218943

  9. Prevention of autoimmune recurrence and rejection by adenovirus-mediated CTLA4Ig gene transfer to the pancreatic graft in BB rat.

    PubMed

    Uchikoshi, F; Yang, Z D; Rostami, S; Yokoi, Y; Capocci, P; Barker, C F; Naji, A

    1999-03-01

    Type 1 diabetes is the result of a selective destruction of pancreatic islets by autoreactive T-cells. Therefore, in the context of islet or pancreas transplantation, newly transplanted beta-cells are threatened by both recurrent autoimmune and alloimmune responses in recipients with type 1 diabetes. In the present study, using spontaneously diabetic BB rats, we demonstrate that whereas isolated islets are susceptible to autoimmune recurrence and rejection, pancreaticoduodenal grafts are resistant to these biological processes. This resistance is mediated by lymphohematopoietic cells transplanted with the graft, since inactivation of these passenger cells by irradiation uniformly rendered the pancreaticoduodenal grafts susceptible to recurrent autoimmunity. We further studied the impact of local immunomodulation on autoimmune recurrence and rejection by ex vivo adenovirus-mediated CTLA4Ig gene transfer to pancreaticoduodenal grafts. Syngeneic DR-BB pancreaticoduodenal grafts transduced with AdmCTLA4Ig were rescued from recurrent autoimmunity. In fully histoincompatible LEW-->BB transplants, in which rejection and recurrence should be able to act synergistically, AdmCTLA4Ig transduced LEW-pancreaticoduodenal allografts enjoyed markedly prolonged survival in diabetic BB recipients. In situ reverse transcription-polymerase chain reaction revealed that transferred CTLA4Ig gene was strongly expressed in both endocrine and exocrine tissues on day 3. These results indicate the potential utility of local CD28-B7 costimulatory blockade for prevention of alloimmune and autoimmune destruction of pancreatic grafts in type 1 diabetic hosts. PMID:10078573

  10. 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

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

    PubMed Central

    Schulz, Tim; Pries, Alexandra; Kapischke, Matthias

    2016-01-01

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

  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. 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.

  14. 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.

  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. Management of Contaminated Autologous Grafts in Plastic Surgery

    PubMed Central

    Centeno, Robert F; Desai, Ankit R; Watson, Marla E

    2008-01-01

    Background: Contamination of autologous grafts unfortunately occurs in plastic surgery, but the literature provides no guidance for management of such incidents. Methods: American Society of Aesthetic Plastic Surgery members were asked to complete an online survey that asked about the number and causes of graft contaminations experienced, how surgeons dealt with the problem, the clinical outcomes, and patient disclosure. Results: Nineteen hundred surgeons were asked to participate in the survey, and 223 responded. Of these, 70% had experienced at least 1 graft contamination incident, with 26% experiencing 4 or more. The most frequently reported reason for graft contamination was a graft falling on the floor (reported by 75%). Nearly two thirds of the contaminated grafts related to craniofacial procedures. Ninety-four percent of grafts were managed with decontamination and completion of the operation. The most common method of decontamination was washing with povidone-iodine, but this practice is contrary to recommendations in the literature. Only 3 surgeons (1.9%) said a clinical infection developed following decontaminated graft use. Patients were not informed in 60% of graft contamination incidents. The survey results and review of the literature led to development of algorithms for the management of inadvertent graft contamination and patient disclosure. Conclusions: Although autologous grafts do become contaminated in plastic surgery, the overwhelming majority can be safely decontaminated and produce minimal or no clinical sequelae. The algorithms presented are intended to serve as guides for prevention of contamination events or for their management should they occur. PMID:18496583

  17. Clinical use of low porosity woven ultrafine polyester fiber grafts.

    PubMed

    Satoh, S; Niu, S; Kanda, K; Hirai, J; Nakazima, S; Wada, Y; Oka, T; Noishiki, Y

    1995-01-01

    A woven fabric graft made of ultrafine polyester fibers (UFPF) (Toray Graft, water porosity: 100 ml/min/cm2:120 mm Hg H2O) was clinically applied in 81 cases (28 thoracic aortic aneurysms, 6 thoracoabdominal aortic aneurysms, 42 abdominal aortic aneurysms, and 5 atherosclerotic obstructions of the peripheral arteries). Eight patients died after surgery due to causes unrelated to the graft. The other 73 patients were in good condition after surgery. For operations requiring extracorporeal circulation, the graft was presealed with human albumin. For the abdominal aortic aneurysms, the graft was preclotted in situ with nonheparinized autoblood after the completion of the proximal anastomosis. It took about 2 min to complete the preclotting. A nonsealed graft was used for the reconstruction of peripheral arteries for the intraaortic balloon pumping procedure. The graft was easy to handle. There was no cut edge fraying problem with the graft in any direction of cutting. Even after presealing, the graft was soft and pliable enough to enable easy adaptation and anastomosis. Just after implantation, bleeding was minimal from the graft wall, anastomotic sites, and suture pores, and it stopped spontaneously. These clinical data showed that the woven UFPF graft exhibited both easy handling despite in spite of low porosity and safe application in the reconstruction of arterial systems even under totally heparinized conditions during extracorporeal circulation. PMID:7741640

  18. Successful treatment of an infected thoracic endovascular stent graft.

    PubMed

    Sueda, Taijiro; Takahashi, Shinya; Katayama, Keijiro; Imai, Katsuhiko

    2016-05-01

    A 70-year-old man with a chronic type B aortic dissection was treated with two stent grafts deployed in the descending thoracic aorta. The patient was re-admitted to the hospital at 16 months after thoracic endovascular stent grafting because of a high fever. A blood culture showed sepsis due to a Staphylococcus species. A CT scan showed an increase in the size of the thrombosed false lumen. Complete excision of the infected descending aortic wall and infected stent graft were performed. The descending thoracic aorta was reconstructed using a rifampicin-bonded Dacron graft and omental wrapping. The combination of in situ graft replacement using a rifampicin-bonded graft and omental wrapping is considered an effective treatment for thoracic stent graft infection. PMID:24990657

  19. Radiographic Implications of Fat Grafting to the Reconstructed Breast.

    PubMed

    Pinell-White, Ximena A; Etra, Joanna; Newell, Mary; Tuscano, Daymen; Shin, Kyungmin; Losken, Albert

    2015-01-01

    Autologous fat transfer is often used to smooth contour irregularities in the reconstructed breast. A potential concern with this technique is that it results in calcified lesions in the breast that can complicate subsequent cancer surveillance. The purpose of this review was to determine how fat grafting to the reconstructed breast impacts postoperative breast imaging. This is a matched cohort analysis of patients who underwent postmastectomy breast reconstruction with and without fat grafting as a secondary procedure. Nonfat grafted reconstructive patients were matched based on age, year of initial reconstruction, and type of reconstruction. Postoperative imaging at our institution was required for inclusion. The two groups were compared in terms of incidence and distribution of radiographic studies performed in follow-up and the need for biopsies. Fifty-one reconstructed breasts with a history of fat grafting were compared to 51 nonfat grafted, reconstructed breasts. The fat grafted group underwent a total of 204 breast imaging studies over a mean follow-up of 4.2 years, while the nonfat grafted group underwent 167 studies over 4.1 years (p = 0.21). More mammograms, ultrasounds, and magnetic resonance images were performed after fat grafting, but a significant difference was evident only for mammography (34 versus 12, p = 0.05). The incidence of breast biopsy to clarify abnormal imaging was nonsignificantly higher in the fat grafted group (17.6% versus 7.8%, p = 0.14). Fewer than 10 percent of imaging studies in the fat grafted cohort were performed to investigate a clinical or radiographic abnormality occupying the same breast quadrant as prior fat injection. Breast cancer patients treated with fat grafting required more breast imaging and biopsies than their nonfat grafted counterparts, but the areas of suspicion poorly corresponded to the site of prior fat grafting. Multimodal breast reconstruction may drive the additional diagnostic burden and not the fat

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

    PubMed Central

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

    2015-01-01

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

  1. 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

  2. Cyclic olefin copolymer based microfluidic devices for biochip applications: Ultraviolet surface grafting using 2-methacryloyloxyethyl phosphorylcholine

    PubMed Central

    Jena, Rajeeb K.; Yue, C. Y.

    2012-01-01

    This report studies the surface modification of cyclic olefin copolymer (COC) by 2-methacryloyloxyethyl phosphorylcholine (MPC) monomer using photografting technique for the purpose of biointerface applications, which demonstrate resistance to both protein adsorption and cell adhesion in COC-based microfluidic devices. This is essential because the hydrophobic nature of COC can lead to adsorption of specific compounds from biological fluids in the microchannel, which can affect the results during fluidic analysis and cause clogging inside the microchannel. A correlation was found between the irradiation time and hydrophobicity of the modified substrate. Static water contact angle results show that the hydrophilicity property of the MPC-grafted substrate improves with increasing irradiation time. The contact angle of the modified surface decreased to 20 ± 5° from 88 ± 3° for the untreated substrate. The surface characterization of the modified surface was evaluated using x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR spectroscopy). Attenuated total reflection-FTIR and XPS results show the presence of the phosphate group (P-O) on modified COC substrates, indicating that the hydrophilic MPC monomer has successfully grafted on COC. Finally, it was demonstrated that cell adhesion and protein adsorption on the MPC modified COC specimen has reduced significantly. PMID:22662089

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. Crystalline structure of polypropylene in blends with thermoplastic elastomers after electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Steller, Ryszard; Żuchowska, Danuta; Meissner, Wanda; Paukszta, Dominik; Garbarczyk, Józef

    2006-02-01

    Isotactic polypropylene (PP) was blended in extruder with 0-50% addition of styrene-ethylene/butylene-styrene (SEBS) and styrene-butadiene-styrene (SBS) block copolymers. Granulated blends were irradiated with electron beam (60 kGy) and 1 week later processed with injection molding machine. Properties of samples molded from irradiated and non-irradiated granulates were investigated using DSC, WAXS, MFR, SEM and mechanical and solubility tests. It was found that the SEBS based systems are more resistant to irradiation in comparison to similar blends with SBS copolymer. Such behavior can be explained by the presence of double bonds in elastic SBS block. Irradiation of PP-SBS blends leads to considerable structure changes of crystalline and amorphous PP phases and elastic SBS phase. It indicates creation of new (inter)phase consisting of products of grafting and cross-linking reactions. Irradiated PP-SBS blends show significant improvement of impact strength at low temperatures.

  8. Assessment laser phototherapy on bone defects grafted or not with biphasic synthetic micro-granular HA + β-tricalcium phosphate: histological study in an animal model

    NASA Astrophysics Data System (ADS)

    Soares, Luiz Guilherme P.; Marques, Aparecida M. C.; Aciole, Jouber Mateus S.; Trindade, Renan; Santos, Jean N.; Pinheiro, Antônio Luiz B.

    2014-02-01

    Beside of biomaterials, Laser phototherapy has shown positive results as auxiliary therapy on bone repair. The aim of this study was to evaluate, through histological analysis, the influence of Laser phototherapy in the process of repair of bone defects grafted or not with Hydroxyapatite. Forty rats were divided into 4 groups each subdivided into 2 subgroups according to the time of sacrifice. Surgical bone defects were made on femur of each animal with a trephine drill. On animals of group Clot the defect was filled only by blood, on group Laser the defect filled with the clot and further irradiated. In group Biomaterial the defect was filled with HA + β-TCP graft. In group Laser + Biomaterial, the defect was filled with biomaterial and further irradiated. The irradiation protocols were performed every 48 hours during for 15 days. Animal death occurred after 15 and 30 days. The specimens were routinely processed and evaluated by light microscopy. Qualitative analysis showed that group Laser + Biomaterial was in a more advanced stage of repair at the end of the experimental time. It was concluded that the Laser irradiation improved the repair of bone defects grafted or not.

  9. Primary Graft Failure after Heart Transplantation

    PubMed Central

    Iyer, Arjun; Kumarasinghe, Gayathri; Hicks, Mark; Watson, Alasdair; Gao, Ling; Doyle, Aoife; Keogh, Anne; Kotlyar, Eugene; Hayward, Christopher; Dhital, Kumud; Granger, Emily; Jansz, Paul; Pye, Roger; Spratt, Phillip; Macdonald, Peter Simon

    2011-01-01

    Primary graft failure (PGF) is a devastating complication that occurs in the immediate postoperative period following heart transplantation. It manifests as severe ventricular dysfunction of the donor graft and carries significant mortality and morbidity. In the last decade, advances in pharmacological treatment and mechanical circulatory support have improved the outlook for heart transplant recipients who develop this complication. Despite these advances in treatment, PGF is still the leading cause of death in the first 30 days after transplantation. In today's climate of significant organ shortages and growing waiting lists, transplant units worldwide have increasingly utilised “marginal donors” to try and bridge the gap between “supply and demand.” One of the costs of this strategy has been an increased incidence of PGF. As the threat of PGF increases, the challenges of predicting and preventing its occurrence, as well as the identification of more effective treatment modalities, are vital areas of active research and development. PMID:21837269

  10. Grafting Sulfated Zirconia on Mesoporous Silica

    SciTech Connect

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

    2007-06-01

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

  11. Limb conservation using non vascularised fibular grafts.

    PubMed

    Omololu, B; Ogunlade, S O; Alonge, T O

    2002-01-01

    This paper highlights the use of non-vascularised fibular graft in limb reconstruction from bone loss due to trauma and infection. Bone loss can occur from severe high velocity injuries due to road traffic accidents, severe neglected infections, and osteolytic tumours. In majority of cases, the surgeon is left with the only option of an amputation especially where there is no access to microvascular surgery and microvascular bone grafting devices. This is a major problem in the West African subregion hence the need for this article. We present illustrative cases of limb conservation in an adult involved in a high velocity trauma and a child with a destructive osteolytic infection culminating in bone loss. The patients are still been followed up in our surgical outpatient clinics. PMID:12665286

  12. Delayed Graft Function in the Kidney Transplant

    PubMed Central

    Siedlecki, Andrew; Irish, William; Brennan, Daniel C.

    2012-01-01

    Acute kidney injury occurs with kidney transplantation and too frequently progresses to the clinical diagnosis of delayed graft function (DGF). Poor kidney function in the first week of graft life is detrimental to the longevity of the allograft. Challenges to understand the root cause of DGF include several pathologic contributors derived from the donor (ischemic injury, inflammatory signaling) and recipient (reperfusion injury, the innate immune response, and the adaptive immune response). Progressive demand for renal allografts has generated new organ categories which continue to carry high risk for DGF for deceased donor organ transplantation. New therapies seek to subdue the inflammatory response in organs with high likelihood to benefit from intervention. Future success in suppressing the development of DGF will require a concerted effort to anticipate and treat tissue injury throughout the arc of the transplantation process. PMID:21929642

  13. Graft copolymer separators — development and use

    NASA Astrophysics Data System (ADS)

    Lovell, K. V.; Adams, L. B.

    Graft copolymer membranes have been used for a number of years as interelectrode separators in alkaline batteries either singly, laminated to cellophane, or in conjunction with other materials such as felts. The preparation details of some of the Royal Military College of Science's copolymers are summarised with emphasis on the production of commercial quantities having a high degree of uniformity and reproducibility. Important properties in a battery environment are discussed and, where possible, compared with other separator materials; notably cellophane. The use of graft copolymers in a number of primary and secondary alkaline battery systems is reported and test data given. Conclusions are drawn relating the properties of these separators to their performance in cells.

  14. 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.

  15. Bone grafts, bone substitutes and orthobiologics

    PubMed Central

    Roberts, Timothy T.; Rosenbaum, Andrew J.

    2012-01-01

    The biology of fracture healing is better understood than ever before, with advancements such as the locking screw leading to more predictable and less eventful osseous healing. However, at times one’s intrinsic biological response, and even concurrent surgical stabilization, is inadequate. In hopes of facilitating osseous union, bone grafts, bone substitutes and orthobiologics are being relied on more than ever before. The osteoinductive, osteoconductive and osteogenic properties of these substrates have been elucidated in the basic science literature and validated in clinical orthopaedic practice. Furthermore, an industry built around these items is more successful and in demand than ever before. This review provides a comprehensive overview of the basic science, clinical utility and economics of bone grafts, bone substitutes and orthobiologics. PMID:23247591

  16. Autologous Fat Grafting Improves Facial Nerve Function

    PubMed Central

    Klinger, Marco; Lisa, Andrea; Caviggioli, Fabio; Maione, Luca; Murolo, Matteo; Vinci, Valeriano; Klinger, Francesco Maria

    2015-01-01

    We describe the case of a 45-year-old male patient who presented a retractile and painful scar in the nasolabial fold due to trauma which determined partial motor impairment of the mouth movements. We subsequently treated him with autologous fat grafting according to Coleman's technique. Clinical assessments were performed at 5 and 14 days and 1, 3, and 6 months after surgical procedure and we observed a progressive release of scar retraction together with an important improvement of pain symptoms. A second procedure was performed 6 months after the previous one. We observed total restoration of mimic movements within one-year follow-up. The case described confirms autologous fat grafting regenerative effect on scar tissue enlightening a possible therapeutic effect on peripheral nerve activity, hypothesizing that its entrapment into scar tissue can determine a partial loss of function. PMID:26167327

  17. Insolubilisation of biologically active materials with novel radiation graft copolymers

    NASA Astrophysics Data System (ADS)

    Garnett, J. L.; Jankiewicz, S. V.; Levot, R.; Sangster, D. F.

    The use of radiation grafting to immobilise a typical enzyme, trypsin, is reported. The technique involves radiation grafting to a backbone polymer a monomer containing an appropriate functional group to which the enzyme is bonded. In the present work, p-nitrostyrene has been grafted to representative trunk polymers, polypropylene and PVC, the nitro group in the resulting copolymer converted to the isothiocyanato derivative to which trypsin is attached. Of importance to this insolubilisation process, especially for radiation sensitive backbone polymers, is the inclusion of additives which enhance grafting. A new class of additives which increase the grafting yields is reported using as representative backbone polymers, naturally occurring cellulose and synthetic low density polyethylene. The new additives are specific metal salts such as LiClO 4. The reactivity of these salts in grafting enhancement has been compared with that of mineral acid which has previously been used as an additive to increase grafting yields in both preirradiation and simultaneous techniques. A new model for grafting enhancement in the presence of the metal salts as well as acids is proposed whereby increased grafting yields are attributed to increased partitioning of monomer into the graft region in the presence of ionic solutes. The value of these additives in preparing copolymers suitable for general reagent insolubilisation reactions is discussed.

  18. Radiation initiated grafting onto fluoro polymers for membrane preparation

    NASA Astrophysics Data System (ADS)

    El-Assy, N. B.; Dessouki, A. M.

    The radiation initiating grafting of acrylamide (AAm) onto poly(tetrafluoroethylene/ hexafluoropropylene/vinylidene fluoride), TFB, films using the post-radiation grafting technique has been investigated. The factors affecting the grafting process such as radiation dose, dose rate, monomer concentration and temperature on the grafting yield were studied. It was found that the grafting yield is strongly dependent on the dose but independent on the dose rate. The dependence of the grafting rate on monomer concentration was found to be of 1.44 order. The results showed a steady increase of the initial grafting rate with temperature, whereas the final grafting yield passes a maximum around 45°C. The Arrhenius plot reveals two straight lines with different slope intersecting around 35°C. The overall activation energy for this grafting system was calculated and found to be 16.5 and 32.4 kcal/mol above and below 35°C, respectively. This behaviour is presumably correlated to a glass transition of the trunk polymer arising from amorphous material under restraint by crystallites. Some properties of the grafted films such a specific electric resistance, water uptake, mechanical properties and chemical and thermal stability were investigated. An improvement in these properties was observed which makes possible the use of these membranes in some practical applications.

  19. PRFM enhance wound healing process in skin graft.

    PubMed

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

    2014-12-01

    Facial plastic and reconstructive surgery often used skin graft on defects that cannot be covered primarily by a local flap. However, wound healing using skin graft is slow, most of the time the graft is contractured and the take of graft is not optimal. Platelet rich fibrin matrix (PRFM) is a new generation of concentrated platelets that produce natural fibrin and reported to speed up the healing process. Application of PRFM in the skin graft implants is expected to increase the survival of the graft. We used porcine as animal models to elucidate the effect of autologous PRFM on wound healing in full-thickness (FTSG) and split-thickness (STSG) skin grafts. Survival level of the skin graft was determined by using ImageJ software based on the formation of collagen type 1 and graft take. We observed that the use of PRFM in FTSG and STSG increased type 1 collagen formation. We also found that PRFM addition in STSG gave the best skin graft take. PMID:25536135

  20. 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.

  1. Gene therapy for the prevention of vein graft disease

    PubMed Central

    Southerland, Kevin W.; Frazier, Sarah B.; Bowles, Dawn E.; Milano, Carmelo A.; Kontos, Christopher D.

    2013-01-01

    Ischemic cardiovascular disease remains the leading cause of death worldwide. Despite advances in the medical management of atherosclerosis over the past several decades, many patients require arterial revascularization to reduce mortality and alleviate ischemic symptoms. Technological advancements have led to dramatic increases in the use of percutaneous and endovascular approaches, yet surgical revascularization (bypass surgery) with autologous vein grafts remains a mainstay of therapy for both coronary and peripheral artery disease. Although bypass surgery is highly efficacious in the short-term, long-term outcomes are limited by relatively high failure rates as a result of intimal hyperplasia, which is a common feature of vein graft disease. The supply of native veins is limited, and many individuals require multiple grafts and repeat procedures. The need to prevent vein graft failure has led to great interest in gene therapy approaches to this problem. Bypass grafting presents an ideal opportunity for gene therapy, as surgically harvested vein grafts can be treated with gene delivery vectors ex vivo, thereby maximizing gene delivery while minimizing the potential for systemic toxicity and targeting the pathogenesis of vein graft disease at its onset. Here we will review the pathogenesis of vein graft disease and discuss vector delivery strategies and potential molecular targets for its prevention. We will summarize the preclinical and clinical literature on gene therapy in vein grafting and discuss additional considerations for future therapies to prevent vein graft disease. PMID:23274305

  2. 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.

  3. 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

  4. 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.

  5. Synthesis and characterization of N-vinylcaprolactam/N,N-dimethylacrylamide grafted onto chitosan networks by gamma radiation

    NASA Astrophysics Data System (ADS)

    Pérez-Calixto, M. P.; Ortega, A.; Garcia-Uriostegui, L.; Burillo, G.

    2016-02-01

    N-vinylcaprolactam (NVCL) and N,N-dimethylacrylamide (DMAAm) were grafted onto crosslinked chitosan by gamma radiation, using direct and indirect (pre-irradiation oxidative) methods. The binary graft systems were synthesized in one and two steps to evaluate the influences of architecture on the properties of the polymeric material. Maximum grafting percentages were obtained by the direct method. The different systems obtained were characterized by FTIR and TGA. The equilibrium swelling time of the (net-CS)-g-NVCL/DMAAm and [(net-CS)-g-NVCL]-g-DMAAm systems was 75 and 25 min, respectively, while crosslinked CS required about 24 h. Thermal and pH sensitivity were conserved in all systems; the pH response in [(net-CS)-g-NVCL]-g-DMAAm (LCST: 37°, pH: 5.2) is more defined than (net-CS)-g-NVCL/DMAAm (LCST: 37 °C, pH: 3.8). Grafting radiation showed to be an effective technique to modify CS hydrogels.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. [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

  15. 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. PMID:25883073

  16. 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.

  17. 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

  18. [Tissue grafts: an activity concerning many patients].

    PubMed

    Loty, B

    1997-11-15

    Tissue allografts mainly include corneas, bone (and cartilage, tendon, ligament, aponevrosis), skin, vessels and cardiac valves. All these grafts have been widely used for many years and were the subject of a large number of experimental and clinical studies. The different steps allowing the obtention of different tissue allografts have in fact a common organization through tissue procurement and banking activities. Tissue banks have a central situation ensuring security, safety, traceability and distribution of tissues. Appropriate organization of the banks, and respect of high level standards are thus mandatory. Tissue transplantation activity in France has been studied through national surveys: they concern more than 600 hospitals and clinics, and grafts procured in France (excluding imported allografts) are around 15,000 a year. Precise regulation implied by the bioethical law published in 1994 and homogeneous organization of the activity allow the use of stringent and regularly updated standards, allowing the distribution to the patients of safe grafts procured in ethical conditions. The actual shortage of tissue allografts in France implies increasing procurement through a better organization of retrieval in hospitals and clinics and donation promotion. PMID:9501596

  19. 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

  20. 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.

  1. Protective constriction of coronary vein grafts with knitted nitinol

    PubMed Central

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

    2013-01-01

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

  2. 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.

  3. 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. PMID:27333009

  4. 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...

  5. Two-dimensional computational model for electrostrictive graft elastomer

    NASA Astrophysics Data System (ADS)

    Wang, Youqi; Sun, Xuekun; Sun, Changjie; Su, Ji

    2003-07-01

    The electrostrictive graft elastomer is a new type of electromechanically active polymer. Recently developed by NASA, it consists of flexible backbone chains, each with side chains, called grafts. Grafts from neighboring backbones physically cross-link and form crystal units. The flexible backbone chains and the crystal graft units are composed of polarized monomers, which contain atoms with electric partial charges, generating dipole moments. Polarized domains are created by dipole moments in the crystal units. When the elastomer is placed into an electric field, external rotating moments are applied to polarized domains. It stimulates the rotation of the polarized crystal graft units, which further induces deformation of the elastomer. In this paper, two-dimensional computational models are established to analyze the deformation mechanism of the graft elastomer.

  6. Liver transplantation utilizing a severely fractured graft: every organ counts.

    PubMed

    Fong, Zhi Ven; Patel, Madhukar S; Yeh, Heidi; Markmann, James F; Vagefi, Parsia A

    2016-01-01

    In our current era where shortage of liver grafts is commonplace, utilization of traumatic liver grafts may represent an opportunity to expand the organ donor pool without compromising graft survival. However, data on liver transplantation using a fractured liver allograft is scarce, with only small case series and reports found in the literature. In this report, we describe our experience with utilizing a liver graft with grade IV hepatic fracture for transplantation. At 12 months follow up, the recipient has excellent graft function and has regained an excellent quality of life. We demonstrated that the ability to safely use a fractured liver graft represents an additional avenue for expansion of the deceased donor population, especially in regions with prolonged waitlist times. PMID:26626650

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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.

  12. Inflammatory reaction as an occlusive mechanism in aortocoronary bypass grafts?

    PubMed

    Svendsen, E; Dalen, H; Moland, J; Engedal, H

    1986-01-01

    Morphological changes in aortocoronary vein grafts are described in two cases; one dying 5 hours post operatively and the other reoperated 8 months after aortocoronary bypass surgery for graft occlusion. Occlusive thrombi and fibrin deposition on the intimal surface and a focal inflammatory process in the wall of the vein grafts were found in the former. Thrombotic encrustation and organization similar to the manifestations of the thrombogenic theory of atherosclerosis were demonstrated in the latter. PMID:3489720

  13. Oxidative product formation in irradiated neutrophils. A flow cytometric analysis

    SciTech Connect

    Wolber, R.A.; Duque, R.E.; Robinson, J.P.; Oberman, H.A.

    1987-03-01

    The effect of irradiation on neutrophil oxidative function was evaluated using a flow cytometric assay of intracellular hydrogen peroxide (H/sub 2/O/sub 2/) production. This assay quantitates the H/sub 2/O/sub 2/-dependent conversion of the nonfluorescent compound, 2'-7'-dichlorofluorescein (DCFH), into fluorescent 2'-7'-dichlorofluorescein (DCF) on a single-cell basis. Intracellular H/sub 2/O/sub 2/ production in response to stimulation with phorbol myristate acetate was not affected by neutrophil irradiation at doses up to 2500 rad. In addition, irradiation of intracellular DCFH and aqueous 2'-7'-dichlorofluorescein diacetate (DCFH-DA) resulted in DCF production, which suggested that oxidative molecules produced by aqueous radiolysis were detected by this assay. This study indicates that radiation doses of 1500 to 2500 rad, which are sufficient to prevent induction of graft-versus-host disease by transfused blood components, are not deleterious to neutrophil oxidative metabolism.

  14. Thermoresponsive poly[tri(ethylene glycol) monoethyl ether methacrylate]-peptide surfaces obtained by radiation grafting-synthesis and characterisation.

    PubMed

    Adamus, A; Komasa, J; Kadłubowski, S; Ulański, P; Rosiak, J M; Kawecki, M; Klama-Baryła, A; Dworak, A; Trzebicka, B; Szweda, R

    2016-09-01

    This report demonstrates the feasibility of radiation grafting for the preparation of polymer layers functionalised with short peptide ligands which promote cell adhesion. Thermoresponsive poly [tri(ethylene glycol) monoethyl ether methacrylate] (PTEGMA) layers were synthesised on a polypropylene substrate by post-irradiation grafting. A cell adhesion moiety, the CF-IKVAVK peptide modified with a methacrylamide function and a fluorescent label were introduced to the surface during the polymerisation process. The amount of CF-IKVAVK was easily controlled by changing its concentration in the reaction mixture. The changes in the surface composition, morphology, philicity and thickness at each step of the polypropylene functionalisation confirmed that the surface modification procedures were successful. The increase in environmental temperature above the cloud point temperature of PTEGMA caused a decrease in surface philicity. The obtained PTEGMA and PTEGMA-peptide surfaces above TCP were tested as scaffolds for fibroblast sheet culture and temperature induced detachment. PMID:27182653

  15. 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.

  16. pH responsive graft copolymers of chitosan.

    PubMed

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

    2016-09-01

    Grafting suitable polymers onto chitosan can produce cationic or polyampholyte polymers or hydrogels that are potential smart biomedical materials. Chitosan-graft-[poly(diethylamino)ethyl methacrylate] has been prepared in three different physical forms as linear free chains in solution, chemical gels crosslinked with glutaraldehyde, and poly(diethylamino)ethyl methacrylate] grafted onto chitosan tripolyphosphate gel beads. In addition to chemical structure, the graft copolymers were characterized with respect to their dissolution and swelling behavior in aqueous solution. It has been established that solubility of the products is controlled by the grafting yield. While pH sensitive polymers, which collapse at a given pH value are obtained at lower grafting yields, hydrogels form at higher grafting yields with pH responsive swelling behavior. Glutaraldehyde crosslinked chitosan-graft-[poly(diethylamino)ethyl methacrylate] gels and chitosan tripolyphosphate gel beads grafted with poly[(diethylamino)ethyl methacrylate] exhibit pH sensitive swelling with highest equilibrium swelling capacity at pH=1.2. PMID:26500176

  17. 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

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

    PubMed Central

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

    2016-01-01

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

  19. 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

  20. 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