Renal PGC1α May Be Associated with Recovery after Delayed Graft Function.

PubMed

Drury, Erika R; Zsengeller, Zsuzsanna K; Stillman, Isaac E; Khankin, Eliyahu V; Pavlakis, Martha; Parikh, Samir M

2018-01-01

Delayed renal graft function (DGF) contributes to the determination of length of hospitalization, risk of acute rejection, and graft loss. Existing tools aid the diagnosis of specific DGF etiologies such as antibody-mediated rejection, but markers of recovery have been elusive. The peroxisome proliferator gamma co-activator-1-alpha (PGC1α) is highly expressed in the renal tubule, regulates mitochondrial biogenesis, and promotes recovery from experimental acute kidney injury. We aimed to determine the association between renal allograft PGC1α expression and recovery from delayed graft function. We retrospectively analyzed patients undergoing renal transplantation at a single center from January 1, 2008 to June 30, 2014. PGC1α expression was assessed by immunostaining and ultrastructural characteristics by transmission electron microscopy. Of 34 patients who underwent renal biopsy for DGF within 30 days of transplant, 21 were included for analysis. Low PGC1α expression was associated with a significantly longer time on dialysis after transplant (median of 35.5 vs. 16 days, p < 0.05) and a significantly higher serum creatinine (sCr) at 4 weeks after transplantation among those who discontinued dialysis (5 vs. 1.65 mg/dL, p < 0.0001). Low PGC1α expression was not associated with higher sCr at 12 weeks after transplantation. Ultrastructural characteristics including apical membrane blebbing and necrotic luminal debris were not informative regarding clinical outcomes. These data suggest that higher PGC1α expression is associated with faster and more complete recovery from DGF. Mitochondrial biogenesis may be a therapeutic target for DGF. Larger studies are needed to validate these findings. © 2017 S. Karger AG, Basel.

rs3212227 SNP in the IL12B Gene Prevents Delayed Graft Function after Kidney Transplantation.

PubMed

Perovic, Vladimir; Markovic, Milos; Kravljaca, Milica; Milosevic, Emina; Djoric, Milica; Pravica, Vera; Naumovic, Radomir

2018-05-10

Transplantation is the best treatment option for end stage kidney disease. The most common early complications in post-transplant period are acute rejection (AR) of the graft and delayed graft function (DGF). The underlying mechanisms in these events are heterogeneous and at least in part involve cytokine genes which regulate immune response to allograft. We have investigated whether functional single nucleotide polymorphisms (SNP) in the genes encoding IFN-γ (IFNG), TNF (TNFA), IL-10 (IL10) and p40 subunit of IL-12/IL-23 (IL12B) could predict risk of AR and DGF in kidney allograft recipients. Our study involved 152 kidney transplant recipients on standard immunosuppressive regimen which included calcineurin inhibitors, mycophenolic acid derivatives and corticosteroids. Genotyping of IFNG, TNFA, IL10 and IL12B was performed using commercial TaqMan assays. We found association between the carriers of AA genotype of IL12B +1188A/C polymorphism (rs3212227) and a lower rate of DGF (p = 0.037, OR = 0.45, 95% CI = 0.21-0.96), implying protective role of A allele in the pathogenesis of DGF in kidney transplant recipients, whereas no such association was observed with AR. None of the analyzed SNPs in TNFA (-308G/A), IFNG (+874T/A), IL10 (-1082G/A, -819T/C, -592C/A) were associated with AR or DGF in our patients. Our study shows a preliminary evidence that the AA genotype of rs3212227 SNP in the IL12B gene might be associated with a lower risk for DGF after kidney transplantation. In the future, additional well-designed large studies are required for the validation of our results. Copyright © 2018 IMSS. Published by Elsevier Inc. All rights reserved.

Functional MRI detects perfusion impairment in renal allografts with delayed graft function.

PubMed

Hueper, Katja; Gueler, Faikah; Bräsen, Jan Hinrich; Gutberlet, Marcel; Jang, Mi-Sun; Lehner, Frank; Richter, Nicolas; Hanke, Nils; Peperhove, Matti; Martirosian, Petros; Tewes, Susanne; Vo Chieu, Van Dai; Großhennig, Anika; Haller, Hermann; Wacker, Frank; Gwinner, Wilfried; Hartung, Dagmar

2015-06-15

Delayed graft function (DGF) after kidney transplantation is not uncommon, and it is associated with long-term allograft impairment. Our aim was to compare renal perfusion changes measured with noninvasive functional MRI in patients early after kidney transplantation to renal function and allograft histology in biopsy samples. Forty-six patients underwent MRI 4-11 days after transplantation. Contrast-free MRI renal perfusion images were acquired using an arterial spin labeling technique. Renal function was assessed by estimated glomerular filtration rate (eGFR), and renal biopsies were performed when indicated within 5 days of MRI. Twenty-six of 46 patients had DGF. Of these, nine patients had acute rejection (including borderline), and eight had other changes (e.g., tubular injury or glomerulosclerosis). Renal perfusion was significantly lower in the DGF group compared with the group with good allograft function (231 ± 15 vs. 331 ± 15 ml·min(-1)·100 g(-1), P < 0.001). Living donor allografts exhibited significantly higher perfusion values compared with deceased donor allografts (P < 0.001). Renal perfusion significantly correlated with eGFR (r = 0.64, P < 0.001), resistance index (r = -0.57, P < 0.001), and cold ischemia time (r = -0.48, P < 0.01). Furthermore, renal perfusion impairment early after transplantation predicted inferior renal outcome and graft loss. In conclusion, noninvasive functional MRI detects renal perfusion impairment early after kidney transplantation in patients with DGF. Copyright © 2015 the American Physiological Society.

Randomized Trial of Machine Perfusion Versus Cold Storage in Recipients of Deceased Donor Kidney Transplants With High Incidence of Delayed Graft Function.

PubMed

Tedesco-Silva, Helio; Mello Offerni, Juliano Chrystian; Ayres Carneiro, Vanessa; Ivani de Paula, Mayara; Neto, Elias David; Brambate Carvalhinho Lemos, Francine; Requião Moura, Lúcio Roberto; Pacheco E Silva Filho, Alvaro; de Morais Cunha, Mirian de Fátima; Francisco da Silva, Erica; Miorin, Luiz Antonio; Demetrio, Daniela Priscila; Luconi, Paulo Sérgio; da Silva Luconi, Waldere Tania; Bobbio, Savina Adriana; Kuschnaroff, Liz Milstein; Noronha, Irene Lourdes; Braga, Sibele Lessa; Barsante, Renata Cristina; Mendes Moreira, João Cezar; Fernandes-Charpiot, Ida Maria Maximina; Abbud-Filho, Mario; Modelli de Andrade, Luis Gustavo; Dalsoglio Garcia, Paula; Tanajura Santamaria Saber, Luciana; Fernandes Laurindo, Alan; Chocair, Pedro Renato; Cuvello Neto, Américo Lourenço; Zanocco, Juliana Aparecida; Duboc de Almeida Soares Filho, Antonio Jose; Ferreira Aguiar, Wilson; Medina Pestana, Jose

2017-05-01

This study compared the use of static cold storage versus continuous hypothermic machine perfusion in a cohort of kidney transplant recipients at high risk for delayed graft function (DGF). In this national, multicenter, and controlled trial, 80 pairs of kidneys recovered from brain-dead deceased donors were randomized to cold storage or machine perfusion, transplanted, and followed up for 12 months. The primary endpoint was the incidence of DGF. Secondary endpoints included the duration of DGF, hospital stay, primary nonfunction, estimated glomerular filtration rate, acute rejection, and allograft and patient survivals. Mean cold ischemia time was high but not different between the 2 groups (25.6 ± 6.6 hours vs 25.05 ± 6.3 hours, 0.937). The incidence of DGF was lower in the machine perfusion compared with cold storage group (61% vs. 45%, P = 0.031). Machine perfusion was independently associated with a reduced risk of DGF (odds ratio, 0.49; 95% confidence interval, 0.26-0.95). Mean estimated glomerular filtration rate tended to be higher at day 28 (40.6 ± 19.9 mL/min per 1.73 m 2 vs 49.0 ± 26.9 mL/min per 1.73 m 2 ; P = 0.262) and 1 year (48.3 ± 19.8 mL/min per 1.73 m 2 vs 54.4 ± 28.6 mL/min per 1.73 m 2 ; P = 0.201) in the machine perfusion group. No differences in the incidence of acute rejection, primary nonfunction (0% vs 2.5%), graft loss (7.5% vs 10%), or death (8.8% vs 6.3%) were observed. In this cohort of recipients of deceased donor kidneys with high mean cold ischemia time and high incidence of DGF, the use of continuous machine perfusion was associated with a reduced risk of DGF compared with the traditional cold storage preservation method.

Impact of machine perfusion after long static cold storage on delayed graft function incidence and duration and time to hospital discharge.

PubMed

Matos, Ana Cristina C; Requiao Moura, Lúcio Roberto; Borrelli, Milton; Nogueira, Mario; Clarizia, Gabriela; Ongaro, Paula; Durão, Marcelino Souza; Pacheco-Silva, Alvaro

2018-01-01

Delayed graft function (DGF) is very high in our center (70%-80%), and we usually receive a kidney for transplant after more than 22 hours of static cold ischemia time (CIT). Also, there is an inadequate care of the donors, contributing to a high rate of DGF. We decided to test whether machine perfusion (MP) after a CIT improved the outcome of our transplant patients. We analyzed the incidence of DGF, its duration, and the length of hospital stay (LOS) in patients who received a kidney preserved with MP after a CIT (hybrid perfusion-HP). We included 54 deceased donors kidneys preserved with HP transplanted from Feb/13 to Jul/14, and compared them to 101 kidney transplants preserved by static cold storage (CS) from Nov/08 to May/12. The median pumping time was 11 hours. DGF incidence was 61.1% vs 79.2% (P = .02), median DGF duration was 5 vs 11 days (P < .001), and median LOS was 13 vs 18 days (P < .011), for the HP compared to CS group. The observed reduction of DGF with machine perfusion did not occur in donors over 50 years old. In the multivariate analysis, risk factors for DGF, adjusted for CIT, were donor age (OR, 1.04; P = .005) and the absence of use of MP (OR, 1.54; P = .051). In conclusion, the use of HP contributed to faster recovery of renal function and to a shorter length of hospital stay. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A comparison of graft and patient outcomes following kidney transplantation in extended hour and conventional haemodialysis patients.

PubMed

See, Emily J; Hawley, Carmel M; Cho, Yeoungjee; Toussaint, Nigel D; Agar, John Wm; Pascoe, Elaine M; Lim, Wai H; Francis, Ross S; Collins, Michael G; Johnson, David W

2018-01-08

Differences in early graft function between kidney transplant recipients previously managed with either haemodialysis (HD) or peritoneal dialysis are well described. However, only two single-centre studies have compared graft and patient outcomes between extended hour and conventional HD patients, with conflicting results. This study compared the outcomes of all extended hour (≥24 hours/week) and conventional HD patients transplanted in Australia and New Zealand between 2000 and 2014. The primary outcome was delayed graft function (DGF), defined in an ordinal manner as either a spontaneous fall in serum creatinine of less than 10% within 24 hours, or the need for dialysis within 72 hours following transplantation. Secondary outcomes included the requirement for dialysis within 72 hours post-transplant, acute rejection, estimated glomerular filtration rate at 12 months, death-censored graft failure, all-cause and cardiovascular mortality, and a composite of graft failure and mortality. A total of 4,935 HD patients (378 extended hour HD, 4,557 conventional HD) received a kidney transplant during the study period. Extended hour HD was associated with an increased likelihood of DGF compared with conventional HD (adjusted proportional odds ratio 1.33; 95% confidence interval 1.06-1.67). There was no significant difference between extended hour and conventional HD in terms of any of the secondary outcomes. Compared to conventional HD, extended hour HD was associated with DGF, although long-term graft and patient outcomes were not different. This article is protected by copyright. All rights reserved.

Xenon Treatment Protects Against Cold Ischemia Associated Delayed Graft Function and Prolongs Graft Survival in Rats

PubMed Central

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

2013-01-01

Prolonged hypothermic storage causes ischemia-reperfusion injury (IRI) in the renal graft, which is considered to contribute to the occurrence of the delayed graft function (DGF) and chronic graft failure. Strategies are required to protect the graft and to prolong renal graft survival. We demonstrated that xenon exposure to human proximal tubular cells (HK-2) led to activation of range of protective proteins. Xenon treatment prior to or after hypothermia–hypoxia challenge stabilized the HK-2 cellular structure, diminished cytoplasmic translocation of high-mobility group box (HMGB) 1 and suppressed NF-κB activation. In the syngeneic Lewis-to-Lewis rat model of kidney transplantation, xenon exposure to donors before graft retrieval or to recipients after engraftment decreased caspase-3 expression, localized HMGB-1 within nuclei and prevented TLR-4/NF-κB activation in tubular cells; serum pro-inflammatory cytokines IL-1β, IL-6 and TNF-α were reduced and renal function was preserved. Xenon treatment of graft donors or of recipients prolonged renal graft survival following IRI in both Lewis-to-Lewis isografts and Fischer-to-Lewis allografts. Xenon induced cell survival or graft functional recovery was abolished by HIF-1α siRNA. Our data suggest that xenon treatment attenuates DGF and enhances graft survival. This approach could be translated into clinical practice leading to a considerable improvement in long-term graft survival. PMID:23710625

Glutathione S-transferase iso-enzymes in perfusate from pumped kidneys are associated with delayed graft function

PubMed Central

Hall, Isaac E.; Bhangoo, Ronik S.; Reese, Peter P.; Doshi, Mona D.; Weng, Francis L.; Hong, Kwangik; Lin, Haiqun; Han, Gang; Hasz, Rick D.; Goldstein, Michael J.; Schröppel, Bernd; Parikh, Chirag R.

2014-01-01

Accurate and reliable assessment tools are needed in transplantation. The objective of this prospective, multicenter study was to determine the associations of the alpha and pi iso-enzymes of glutathione S-transferase (GST), measured from perfusate solution at the start and end (base and post) of kidney allograft machine perfusion, with subsequent delayed graft function (DGF). We also compared GST iso-enzyme perfusate levels from discarded versus transplanted kidneys. A total of 428 kidneys were linked to outcomes as recorded by the United Network of Organ Sharing. DGF, defined as any dialysis in the first week of transplant, occurred in 141 recipients (32%). Alpha and pi-GST levels significantly increased during machine perfusion. The adjusted relative risks (95% confidence interval) of DGF with each log-unit increase in base and post pi-GST were 1.14 (1.0-1.28) and 1.33 (1.02-1.72), respectively. Alpha-GST was not independently associated with DGF. There were no significant differences in GST values between discarded and transplanted kidneys, though renal resistance was significantly higher in discarded kidneys. We found pi-GST at the end of machine perfusion to be independently associated with DGF. Further studies should elucidate the utility of GST for identifying injured kidneys with regard to organ allocation, discard and recipient management decisions. PMID:24612768

Impact of early graft function on 10-year graft survival in recipients of kidneys from standard- or expanded-criteria donors.

PubMed

Smail, Nassima; Tchervenkov, Jean; Paraskevas, Steven; Baran, Dana; Mucsi, Istvan; Hassanain, Mazen; Chaudhury, Prosanto; Cantarovich, Marcelo

2013-07-27

The use of kidneys from expanded-criteria donors (ECD) is regarded with caution. We compared 279 kidney transplant recipients (KTxR) from standard-criteria donors (SCD) and 237 from ECD, transplanted between January 1990 and December 2006. We evaluated the impact of immediate graft function (IGF), slow graft function (SGF), and delayed graft function (DGF) and the drop in estimated glomerular filtration rate (ΔeGFR) ≤ 30% or > 30% during the first year after transplantation on long-term patient and death-censored graft survival (DCGS). Ten-year patient survival was similar in SCD- or ECD-KTxR (P = 0.38). DCGS was better in SCD-KTxR versus ECD-KTxR (77.3% vs. 67.3%; P = 0.01). DCGS did not differ in either group experiencing IGF (P = 0.17) or DGF (P = 0.12). However, DCGS was worse in ECD-KTxR experiencing SGF (84.9% vs. 73.7%; P = 0.04). Predictors of DCGS were 1-year serum creatinine (hazard ratio, 1.03; P < 0.0001) and ΔeGFR > 30% between 1 and 12 months (Δ1-12eGFR) after transplantation (hazard ratio, 2.2; P = 0.02). In ECD-KTxR with IGF and more than 1-year follow-up, 10-year DCGS was better in those with Δ1-12eGFR ≤ 30% versus those with Δ1-12eGFR > 30% (83.8% vs. 53.6%; P = 0.01). Recipients of SCD or ECD kidneys with IGF or DGF had similar 10-year patient survival and DCGS. SGF had a worse impact on DCGS in ECD-KTxR. In addition to 1-year serum creatinine, Δ1-12eGFR > 30% is a negative predictor of DCGS. Larger studies should confirm if increasing the use of ECD, avoiding factors that contribute to SGF or DGF, and/or a decline in eGFR during the first year after transplantation may expand the donor pool and result in acceptable long-term outcomes.

Effect of N-Acetylcysteine Pretreatment of Deceased Organ Donors on Renal Allograft Function: A Randomized Controlled Trial

PubMed Central

Orban, Jean-Christophe; Quintard, Hervé; Cassuto, Elisabeth; Jambou, Patrick; Samat-Long, Corine; Ichai, Carole

2015-01-01

Background Antioxidant donor pretreatment is one of the pharmacologic strategy proposed to prevent renal ischemia-reperfusion injuries and delayed graft function (DGF). The aim of the study was to investigate whether a donor pretreatment with N-acetylcysteine (NAC) reduces the incidence of DGF in adult human kidney transplant recipients. Methods In this randomized, open-label, monocenter trial, 160 deceased heart-beating donors were allowed to perform 236 renal transplantations from September 2005 to December 2010. Donors were randomized to receive, in a single-blind controlled fashion, 600 mg of intravenous NAC 1 hr before and 2 hr after cerebral angiography performed to confirm brain death. Primary endpoint was DGF defined by the need for at least one dialysis session within the first week or a serum creatinine level greater than 200 μmol/L at day 7 after kidney transplantation. Results The incidence of DGF was similar between donors pretreated with or without NAC (39/118; 33% vs. 30/118; 25.4%; P = 0.19). Requirement for at least one dialysis session was not different between the NAC and No NAC groups (17/118; 14.4% vs. 14/118; 11.8%, P = 0.56). The two groups had comparable serum creatinine levels, estimated glomerular filtration rates, and daily urine output at days 1, 7, 15, and 30 after kidney transplantation as well as at hospital discharge. No difference in recipient mortality nor in 1-year kidney graft survival was observed. Conclusion Donor pretreatment with NAC does not improve delayed graft function after kidney transplantation. PMID:25250647

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

PubMed

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

2013-08-01

Prolonged hypothermic storage causes ischemia-reperfusion injury (IRI) in the renal graft, which is considered to contribute to the occurrence of the delayed graft function (DGF) and chronic graft failure. Strategies are required to protect the graft and to prolong renal graft survival. We demonstrated that xenon exposure to human proximal tubular cells (HK-2) led to activation of range of protective proteins. Xenon treatment prior to or after hypothermia-hypoxia challenge stabilized the HK-2 cellular structure, diminished cytoplasmic translocation of high-mobility group box (HMGB) 1 and suppressed NF-κB activation. In the syngeneic Lewis-to-Lewis rat model of kidney transplantation, xenon exposure to donors before graft retrieval or to recipients after engraftment decreased caspase-3 expression, localized HMGB-1 within nuclei and prevented TLR-4/NF-κB activation in tubular cells; serum pro-inflammatory cytokines IL-1β, IL-6 and TNF-α were reduced and renal function was preserved. Xenon treatment of graft donors or of recipients prolonged renal graft survival following IRI in both Lewis-to-Lewis isografts and Fischer-to-Lewis allografts. Xenon induced cell survival or graft functional recovery was abolished by HIF-1α siRNA. Our data suggest that xenon treatment attenuates DGF and enhances graft survival. This approach could be translated into clinical practice leading to a considerable improvement in long-term graft survival. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.

Glutathione S-transferase iso-enzymes in perfusate from pumped kidneys are associated with delayed graft function.

PubMed

Hall, I E; Bhangoo, R S; Reese, P P; Doshi, M D; Weng, F L; Hong, K; Lin, H; Han, G; Hasz, R D; Goldstein, M J; Schröppel, B; Parikh, C R

2014-04-01

Accurate and reliable assessment tools are needed in transplantation. The objective of this prospective, multi-center study was to determine the associations of the alpha and pi iso-enzymes of glutathione S-transferase (GST), measured from perfusate solution at the start and end (base and post) of kidney allograft machine perfusion, with subsequent delayed graft function (DGF). We also compared GST iso-enzyme perfusate levels from discarded versus transplanted kidneys. A total of 428 kidneys were linked to outcomes as recorded by the United Network of Organ Sharing. DGF, defined as any dialysis in the first week of transplant, occurred in 141 recipients (32%). Alpha- and pi-GST levels significantly increased during machine perfusion. The adjusted relative risks (95% confidence interval) of DGF with each log-unit increase in base and post pi-GST were 1.14 (1.0-1.3) and 1.36 (1.1-1.8), respectively. Alpha-GST was not independently associated with DGF. There were no significant differences in GST values between discarded and transplanted kidneys, though renal resistance was significantly higher in discarded kidneys. We found pi-GST at the end of machine perfusion to be independently associated with DGF. Further studies should elucidate the utility of GST for identifying injured kidneys with regard to organ allocation, discard and recipient management decisions. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

Influence of deceased donor hemodynamic factors in transplant recipients renal function.

PubMed

Baptista, Ana Paula Maia; Silva, Hélio Tedesco; Pestana, José Osmar Medina

2013-01-01

The incidence of delayed graft function (DGF) and unsatisfactory creatinine clearance (UCC) after renal transplantation is significantly higher in Brazil, when compared with that observed in United States or Europe. Deceased donor (DD) characteristics should directly influence the occurrence of these two outcomes. This study aim to evaluate the influence of DD characteristics on DGF and UCC incidence in Brazil. DD clinical and laboratory variables were correlated with outcome's incidence. We evaluated 787 DD whose organs were transplanted in 1298 patients. We noted a high prevalence of vasoactive drugs use (90.2%), hypernatremia (66.6%) and renal dysfunction (34.8%). The incidence of DGF and UCC was 60.6% and 55.2%, respectively. We observed a progressive increase in DGF risk for age groups over 30 years and for cold ischemia time (CIT) greater than 24 hours. DGF risk was two times higher in recipients of donor kidney final serum creatinine (Cr) over than 1.5 mg/dl. Hypertension and CIT over 36 hours was associated with an increasing of 82% and 99% in UCC risk, respectively. Donor age above 40 years was associated with a progressive increase in UCC risk. DD age, renal function, hypertension and prolonged CIT were associated with increased risk DGF and UCC.

Xenon treatment attenuates early renal allograft injury associated with prolonged hypothermic storage in rats.

PubMed

Zhao, Hailin; Yoshida, Akira; Xiao, Wei; Ologunde, Rele; O'Dea, Kieran P; Takata, Masao; Tralau-Stewart, Catherine; George, Andrew J T; Ma, Daqing

2013-10-01

Prolonged hypothermic storage elicits severe ischemia-reperfusion injury (IRI) to renal grafts, contributing to delayed graft function (DGF) and episodes of acute immune rejection and shortened graft survival. Organoprotective strategies are therefore needed for improving long-term transplant outcome. The aim of this study is to investigate the renoprotective effect of xenon on early allograft injury associated with prolonged hypothermic storage. Xenon exposure enhanced the expression of heat-shock protein 70 (HSP-70) and heme oxygenase 1 (HO-1) and promoted cell survival after hypothermia-hypoxia insult in human proximal tubular (HK-2) cells, which was abolished by HSP-70 or HO-1 siRNA. In the brown Norway to Lewis rat renal transplantation, xenon administered to donor or recipient decreased the renal tubular cell death, inflammation, and MHC II expression, while delayed graft function (DGF) was therefore reduced. Pathological changes associated with acute rejection, including T-cell, macrophage, and fibroblast infiltration, were also decreased with xenon treatment. Donors or recipients treated with xenon in combination with cyclosporin A had prolonged renal allograft survival. Xenon protects allografts against delayed graft function, attenuates acute immune rejection, and enhances graft survival after prolonged hypothermic storage. Furthermore, xenon works additively with cyclosporin A to preserve post-transplant renal function.

Intraoperative red blood cell transfusion, delayed graft function, and infection after kidney transplant: an observational cohort study.

PubMed

Mazzeffi, Michael; Jonna, Srikar; Blanco, Natalia; Mavrothalassitis, Orestes; Odekwu, Obi; Fontaine, Magali; Rock, Peter; Tanaka, Kenichi; Thom, Kerri

2018-06-01

Kidney transplant patients are frequently anemic and at risk for red blood cell (RBC) transfusion. Previous studies suggest that pre-transplant RBC transfusion may improve kidney transplant outcomes; however, RBC transfusion is also associated with infection. The purpose of our study was to characterize the relationships between intraoperative RBC transfusion, delayed graft function (DGF), postoperative surgical site infection (SSI), and sepsis. Analysis was performed on a historical cohort of adult kidney transplant patients from a single medical center during a two-year period. Crude odds ratios for DGF, superficial and deep SSI, and sepsis were calculated for transfused patients and multivariate regression was used to control for potential confounders when significant relationships were identified. Four hundred forty-one patients had kidney transplant during the study period; 27.0% had RBC transfusion, 38.8% had DGF, 7.0% had superficial SSI, 7.9% had deep SSI, and 1.8% had sepsis. High dose RBC transfusion was associated with improved graft function, but this was negated after adjusting for confounders (OR = 0.86, 95% CI  0.26 to 2.88). There was no association between RBC transfusion and SSI. RBC transfusion was independently associated with sepsis (OR = 8.98, 95% CI  1.52 to 53.22), but the confidence interval was wide. Intraoperative RBC transfusion during kidney transplant is not associated with improved allograft function or incisional SSI, but is associated with postoperative sepsis. RBCs should not be liberally transfused during kidney transplant surgery to improve graft outcomes.

Is prolonged cold ischemia a contraindication to using kidneys from acute kidney injury donors?

PubMed

Orlando, Giuseppe; Khan, Muhammad A; El-Hennawy, Hany; Farney, Alan C; Rogers, Jeffrey; Reeves-Daniel, Amber; Gautreaux, Michael D; Doares, William; Kaczmorski, Scott; Stratta, Robert J

2018-03-01

To determine the impact of prolonged cold ischemia time (CIT) on the outcome of acute kidney injury (AKI) renal grafts, we therefore performed a single-center retrospective analysis in adult patients receiving kidney transplantation (KT) from AKI donors. Outcomes were stratified according to duration of CIT. A total of 118 patients receiving AKI grafts were enrolled. Based on CIT, patients were stratified as follows: (i) <20 hours, 27 patients; (ii) 20-30 hours, 52 patients; (iii) 30-40 hours, 30 patients; (iv) ≥40 hours, nine patients. The overall incidence of delayed graft function DGF was 41.5%. According to increasing CIT category, DGF rates were 30%, 42%, 40%, and 78%, respectively (P = .03). With a mean follow-up of 48 months, overall patient and graft survival rates were 91% and 81%. Death-censored graft survival (DCGS) rates were 84% and 88% for patients with and without DGF (P = NS). DCGS rates were 92% in patients with CIT <20 hours compared to 85% with CIT >20 hours (P = NS). In the nine patients with CIT >40 hours, the 4-year DCGS rate was 100%. We conclude that prolonged CIT in AKI grafts may not adversely influence outcomes and so discard of AKI kidneys because of projected long CIT is not warranted when donors are wisely triaged. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The effectiveness and cost-effectiveness of methods of storing donated kidneys from deceased donors: a systematic review and economic model.

PubMed

Bond, M; Pitt, M; Akoh, J; Moxham, T; Hoyle, M; Anderson, R

2009-08-01

To review the evidence for the effectiveness and cost-effectiveness of storing kidneys from deceased donors prior to transplantation, using cold static storage solutions or pulsatile hypothermic machine perfusion. Electronic databases were searched in January 2008 and updated in May 2008 for systematic reviews and/or meta-analyses, randomised controlled trials (RCTs), other study designs and ongoing research. Sources included: Cochrane Library, MEDLINE, EMBASE, CINAHL, ISI Web of Knowledge, DARE, NRR, ReFeR, Current Controlled Trials, and (NHS) HTA. Bibliographies of articles were searched for further relevant studies, and the Food and Drugs Administration (FDA) and European Regulatory Agency Medical Device Safety Service websites were searched. Only English language papers were sought. The perfusion machines identified were the LifePort Kidney Transporter (Organ Recovery Systems) and the RM3 Renal Preservation System (Waters Medical Systems). The cold storage solutions reviewed were: University of Wisconsin, ViaSpan; Marshall's hypertonic citrate, Soltran; and Genzyme, Celsior. Each intervention was compared with the others as data permitted. The population was recipients of kidneys from deceased donors. The main outcomes were measures of graft survival, patient survival, delayed graft function (DGF), primary non-function (PNF), discard rates of non-viable kidneys, health-related quality of life and cost-effectiveness. Where data permitted the results of studies were pooled using meta-analysis. A Markov (state transition) model was developed to simulate the main post-transplantation outcomes of kidney graft recipients. Eleven studies were included: three full journal published RCTs, two ongoing RCTs [European Machine Preservation Trial (MPT) and UK Pulsatile Perfusion in Asystolic donor Renal Transplantation (PPART) study], one cohort study, three full journal published retrospective record reviews and two retrospective record reviews published as posters or abstracts only. For LifePort versus ViaSpan, no significant differences were found for DGF, PNF, acute rejection, duration of DGF, creatinine clearance or toxicity, patient survival or graft survival at 6 months, but graft survival was better at 12 months post transplant with machine perfusion (LifePort = 98%, ViaSpan = 94%, p < 0.03). For LifePort versus RM3, all outcomes favoured RM3, although the results may be unreliable. For ViaSpan versus Soltran, there were no significant differences in graft survival for cold ischaemic times up to 36 hours. For ViaSpan versus Celsior, no significant differences were found on any outcome measure. In terms of cost-effectiveness, data from the MPT suggested that machine preservation was cheaper and generated more quality-adjusted life-years (QALYs), while the PPART study data suggested that cold storage was preferable on both counts. The less reliable deterministic outputs of the cohort study suggested that LifePort would be cheaper and would generate more QALYs than Soltran. Sensitivity analyses found that changes to the differential kidney storage costs between comparators have a very low impact on overall net benefit estimates; where differences in effectiveness exist, dialysis costs are important in determining overall net benefit; DGF levels become important only when differences in graft survival are apparent between patients experiencing immediate graft function (IGF) versus DGF; relative impact of differential changes to graft survival for patients experiencing IGF as opposed to DGF depends on the relative proportion of patients experiencing each of these two outcomes. The conclusions drawn for the comparison of machine perfusion with cold storage depend on which trial data are used in the model. Owing to the lack of good research evidence that either ViaSpan or Soltran is better than the other, the cheaper, Soltran, may be preferable. In the absence of a cost-utility analysis, the results of our meta-analysis of the RCTs comparing ViaSpan with Celsior indicate that these cold storage solutions are equivalent. Further RCTs of comparators of interest to allow for appropriate analysis of subgroups and to determine whether either of the two machines under consideration produces better outcomes may be useful. In addition, research is required to: establish the strength and reliability of the presumed causal association between DGF and graft, and patient survival; investigate the utility impacts of renal replacement therapy; determine what the additional cost, survival and QALY impacts are of decreased or increased non-viable kidneys when discarded pre transplantation; and identify a reliable measure for predicting kidney viability from machine perfusion.

Uncontrolled non-heartbeating donors (types i-ii) with normothermic recirculation vs. heartbeating donors: evaluation of functional results and survival.

PubMed

Miranda-Utrera, N; Medina-Polo, J; Pamplona-Casamayor, M; Passas-Martínez, J B; Rodríguez-Antolín, A; de la Rosa Kehrmann, F; Duarte-Ojeda, J M; Tejido-Sánchez, A; Villacampa Aubá, F; Andrés Belmonte, A

2015-09-01

Non-heartbeating donors (NHBD) are an alternative to heartbeating donors (HBD). Our objective was to compare functional results and kidney survival from NHBDs and HBDs. A retrospective study comparing the results of 236 normothermically preserved kidneys from type i and ii type NHBDs with the results of 250 from HBDs that were transplanted in our center between 2005 and 2012. Homogeneity between groups was tested and we evaluated the presence of delayed graft function (DGF) associated with pretransplant variables of the donor and recipient. Both groups show homogeneity in pretransplant characteristics in terms of: age, HLA incompatibilities, and recipient hemodialysis time. Average follow-up time was 33 months (range 0-87) for NHBDs and 38 months (range 0-90) for HBDs. 5.5% of NHBDs showed primary non-function (PNF) vs. 4% of HBDs (P=.42) and 80.9% of DGF vs. 46.8% of HBDs (P<.001). At the end of the follow-up, there were no statistically significant differences in the survival of grafts (92.8% for NHBD vs. 93.6% for HBD, P=.71) and recipients (99.1% NHBD vs. 98.6% HBD, P=.28). Although the DGF percentage was greater for NHBDs, final creatinine as well as graft and recipient survival were similar for both groups. Therefore, in our experience, kidneys from NHBDs have similar results to those from HBDs and are an excellent source of organs for transplantation. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Negative impact of prolonged cold storage time before machine perfusion preservation in donation after circulatory death kidney transplantation.

PubMed

Paloyo, Siegfredo; Sageshima, Junichiro; Gaynor, Jeffrey J; Chen, Linda; Ciancio, Gaetano; Burke, George W

2016-10-01

Kidney grafts are often preserved initially in static cold storage (CS) and subsequently on hypothermic machine perfusion (MP). However, the impact of CS/MP time on transplant outcome remains unclear. We evaluated the effect of prolonged CS/MP time in a single-center retrospective cohort of 59 donation after circulatory death (DCD) and 177 matched donation after brain death (DBD) kidney-alone transplant recipients. With mean overall CS/MP times of 6.0 h/30.0 h, overall incidence of delayed graft function (DGF) was higher in DCD transplants (30.5%) than DBD transplants (7.3%, P < 0.0001). In logistic regression, DCD recipient (P < 0.0001), longer CS time (P = 0.0002), male recipient (P = 0.02), and longer MP time (P = 0.08) were associated with higher DGF incidence. In evaluating the joint effects of donor type (DBD vs. DCD), CS time (<6 vs. ≥6 h), and MP time (<36 vs. ≥36 h) on DGF incidence, one clearly sees an unfavorable effect of MP time ≥36 h (P = 0.003) across each donor type and CS time stratum, whereas the unfavorable effect of CS time ≥6 h (P = 0.01) is primarily seen among DCD recipients. Prolonged cold ischemia time had no unfavorable effect on renal function or graft survival at 12mo post-transplant. Long CS/MP time detrimentally affects early DCD/DBD kidney transplant outcome when grafts were mainly preserved by MP; prolonged CS time before MP has a particularly negative impact in DCD kidney transplantation. © 2016 Steunstichting ESOT.

Randomized trial of tacrolimus + mycophenolate mofetil or azathioprine versus cyclosporine + mycophenolate mofetil after cadaveric kidney transplantation: results at three years.

PubMed

Gonwa, Thomas; Johnson, Christopher; Ahsan, Nasimul; Alfrey, Edward J; Halloran, Philip; Stegall, Mark; Hardy, Mark; Metzger, Robert; Shield, Charles; Rocher, Leslie; Scandling, John; Sorensen, John; Mulloy, Laura; Light, Jimmy; Corwin, Claudia; Danovitch, Gabriel; Wachs, Michael; VanVeldhuisen, Paul; Leonhardt, Maryanne; Fitzsimmons, William E

2003-06-27

Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus (TAC) + mycophenolate mofetil (MMF), TAC + azathioprine (AZA), or cyclosporine (Neoral; CsA) + MMF. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function (DGF). Patients were followed-up for 3 years. The results at 3 years corroborate and extend the findings of the 2-year results. Patients with DGF treated with TAC+MMF experienced an increase in 3-year allograft survival compared with patients receiving CsA+MMF (84.1% vs. 49.9%, P=0.02). Patients randomized to either treatment arm containing TAC exhibited numerically superior kidney function when compared with CsA. During the 3 years, new-onset insulin dependence occurred in 6, 3, and 11 patients in the TAC+MMF, CsA+MMF, and TAC+AZA treatment arms, respectively. Furthermore, patients randomized to TAC+MMF received significantly lower doses of MMF as compared with those who received CsA+MMF. All three immunosuppressive regimens provided excellent safety and efficacy. However, the best results overall were achieved with TAC+MMF. The combination may provide particular benefit to kidney allograft recipients with DGF. In patients who experienced DGF, graft survival was better at 3 years in those patients receiving TAC in combination with either MMF or AZA as compared with the patients receiving CsA with MMF.

Effect of increased pressure during pulsatile pump perfusion of deceased donor kidneys in transplantation.

PubMed

Patel, S K; Pankewycz, O G; Weber-Shrikant, E; Zachariah, M; Kohli, R; Nader, N D; Laftavi, M R

2012-09-01

Pulsatile pump perfusion of potential kidneys for transplantation is known to decrease the rate of delayed graft function (DGF) and improve their 1-year survival. Flow and resistance parameters are often used to determine the suitability of kidneys for transplantation. Kidneys with low flow rates are often subjected to higher pressures to improve flow. This study evaluated the effect of higher pump pressures on posttransplant renal function. We performed a retrospective analysis of 73 deceased donor kidneys preserved using pump perfusion (LifePort) at our center between May 2006 and September 2009. We calculated the mean pump pressure (MP) for the duration of perfusion of each kidney, using systolic pressure (SP) and diastolic pressure (DP) readings with the following formula: (MP = DP + 1/3 (SP - DP). The kidneys were divided into a low (LP; n = 49) and a high-pressure group (HP; n = 24) based on a MP cutoff value of 23 mm Hg. The two groups were then compared for differences in perfusion dynamics and primary endpoints including DGF and 1-year graft survival. Statistical analysis was performed using paired Student t test and chi-square analysis. The two groups were comparable for donor age, extended criteria, sensitization, and cold ischemic times. They differed significantly in higher initial (0.65 ± 0.4 versus 0.4 ± 0.2, P = .01), average (0.25 ± 0.08 versus 0.18 ± 0.06, P = .0006), and terminal resistance (0.21 ± 0.07 versus 0.17 ± 0.06, P = .008) of HP versus LP kidneys. Flow rates were comparable between the two groups. DGF was higher in HP kidneys (75% versus 40%, P = .006) with similar 1-year graft survival (87.5% versus 89%, P = .7). Perfusate flow through a kidney can be improved by increasing pressure settings to overcome elevated resistance. This maneuver was not associated with a lower rate of DGF after transplantation. One-year graft survival remained unaffected. Copyright © 2012 Elsevier Inc. All rights reserved.

Kidney donation after circulatory death in a country with a high number of brain dead donors: 10-year experience in Belgium.

PubMed

Jochmans, Ina; Darius, Tom; Kuypers, Dirk; Monbaliu, Diethard; Goffin, Eric; Mourad, Michel; Ledinh, Hieu; Weekers, Laurent; Peeters, Patrick; Randon, Caren; Bosmans, Jean-Louis; Roeyen, Geert; Abramowicz, Daniel; Hoang, Anh-Dung; De Pauw, Luc; Rahmel, Axel; Squifflet, Jean-Paul; Pirenne, Jacques

2012-08-01

Worldwide shortage of standard brain dead donors (DBD) has revived the use of kidneys donated after circulatory death (DCD). We reviewed the Belgian DCD kidney transplant (KT) experience since its reintroduction in 2000. Risk factors for delayed graft function (DGF) were identified using multivariate analysis. Five-year patient/graft survival was assessed using Kaplan-Meier curves. The evolution of the kidney donor type and the impact of DCDs on the total KT activity in Belgium were compared with the Netherlands. Between 2000 and 2009, 287 DCD KT were performed. Primary nonfunction occurred in 1% and DGF in 31%. Five-year patient and death-censored graft survival were 93% and 95%, respectively. In multivariate analysis, cold storage (versus machine perfusion), cold ischemic time, and histidine-tryptophan-ketoglutarate solution were independent risk factors for the development of DGF. Despite an increased number of DCD donations and transplantations, the total number of deceased KT did not increase significantly. This could suggest a shift from DBDs to DCDs. To increase KT activity, Belgium should further expand controlled DCD programs while simultaneously improve the identification of all potential DBDs and avoid their referral for donation as DCDs before brain death occurs. Furthermore, living donation remains underused. © 2012 The Authors. Transplant International © 2012 European Society for Organ Transplantation.

Investigation of apoptosis-related gene expression levels in preimplantation biopsies as predictors of delayed kidney graft function.

PubMed

Goncalves-Primo, Amador; Mourão, Tuíla B; Andrade-Oliveira, Vinícius; Campos, Erika F; Medina-Pestana, José O; Tedesco-Silva, Hélio; Gerbase-DeLima, Maria

2014-06-27

The purpose of this study was to investigate the expression of the gene coding for the antiapoptotic molecule Bcl-2, the proapoptotic molecule Bax, and the apoptosis executor enzyme caspase-3 in preimplantation renal biopsies (PIB) as markers for delayed graft function. In this prospective single-center study, gene expression levels were evaluated using real-time TaqMan polymerase chain reaction in PIB of kidneys from 72 deceased donors (DDs) and 18 living donors (LDs). CASP3 and BAX expression levels were higher, whereas those of BCL2 were lower, in DD than in LD PIB. In biopsies from DD, BCL2 levels were lower in cases with DGF, whereas no differences were observed concerning CASP3 and BAX. The BAX/BCL2 gene expression ratio greater than 2.29 associated with DGF with an odds ratio of 2.00. A multiple regression analysis including data of TLR4 expression in the first day posttransplant PB from a previous study of our group conducted in the same patients revealed a very strong association of the combination of BAX/BCL2 greater than 2.3 in PIB and TLR4 of 0.95 uRE or lesser in PB with the occurrence of DGF, with OR of 120 and positive and negative predictive values of 91% and 92%, respectively. The power to predict DGF of the combination of high BAX/BCL2 expression in PIB and low TLR4 expression in the first day posttransplant peripheral blood observed in the present study is extremely high, in comparison to any other marker or combinations of markers so far published in the literature.

Comparison of outcomes of kidney transplantation from donation after brain death, donation after circulatory death, and donation after brain death followed by circulatory death donors.

PubMed

Chen, Guodong; Wang, Chang; Ko, Dicken Shiu-Chung; Qiu, Jiang; Yuan, Xiaopeng; Han, Ming; Wang, Changxi; He, Xiaoshun; Chen, Lizhong

2017-11-01

There are three categories of deceased donors of kidney transplantation in China, donation after brain death (DBD), donation after circulatory death (DCD), and donation after brain death followed by circulatory death (DBCD) donors. The aim of this study was to compare the outcomes of kidney transplantation from these three categories of deceased donors. We retrospectively reviewed 469 recipients who received deceased kidney transplantation in our hospital from February 2007 to June 2015. The recipients were divided into three groups according to the source of their donor kidneys: DBD, DCD, or DBCD. The primary endpoints were delayed graft function (DGF), graft loss, and patient death. The warm ischemia time was much longer in DCD group compared to DBCD group (18.4 minutes vs 12.9 minutes, P < .001). DGF rate was higher in DCD group than in DBD and DBCD groups (22.5% vs 10.2% and 13.8%, respectively, P = .021). Urinary leakage was much higher in DCD group (P = .049). Kaplan-Meier analysis showed that 1-, 2-, and 3-year patient survivals were all comparable among the three groups. DBCD kidney transplantation has lower incidences of DGF and urinary leakage than DCD kidney transplant. However, the overall patient and graft survival were comparable among DBD, DCD, and DBCD kidney transplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

76 FR 42716 - Effects of Ischemia Reperfusion Injury on Outcomes in Kidney Transplantation; Public Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

...] Effects of Ischemia Reperfusion Injury on Outcomes in Kidney Transplantation; Public Workshop AGENCY: Food... outcomes in kidney transplantation. This public workshop is intended to obtain information from health care... for the prophylaxis and/or treatment of delayed graft function (DGF) and related conditions in kidney...

Timely Diagnosis of Acute Kidney Injury Using Kinetic eGFR and the Creatinine Excretion to Production Ratio, E/eG - Creatinine Can Be Useful!

PubMed

Endre, Zoltán H; Pianta, Timothy J; Pickering, John W

2016-01-01

Post transplant repeated measurements of urine volume and serum creatinine (sCr) are used to assess kidney function. Under non-steady state conditions, repeated measurement of sCr allows calculation of the kinetic estimated GFR (KeGFR). Additional measurement of urinary creatinine allows the calculation of the creatinine excretion to (estimated) production ratio (E/eG). We hypothesized that post-transplant KeGFR and E/eG would predict delayed graft function (DGF), as early as 4 h and outperform a validated clinical model at 12 h. This was a retrospective analysis of prospectively acquired data in a study of 56 recipients of deceased-donor kidney transplant. We assessed predictive performance with the area under the receiver operator characteristic curve (AUC) and the added value to a clinical model with integrated discrimination improvement analysis. At 4 h, the AUC for E/eG was 0.87 (95% CI 0.77-0.96) and for KeGFR 0.69 (95% CI 0.56-0.83). Both E/eG and KeGFR improved the risk prediction of a clinical model for DGF by 32 and 18%, and for non-DGF by 17 and 10%, respectively. While E/eG had better predictive performance of DGF than KeGFR, KeGFR might also facilitate perioperative management including drug dosing after kidney transplantation. Together these measurements may facilitate the possibility of conducting trials of early intervention to ameliorate the adverse effects of ischaemia-reperfusion injury on long-term DGF. © 2016 S. Karger AG, Basel.

Outcome of Kidney Transplantation From Donor After Cardiac Death: Reanalysis of the US Mycophenolic Renal Transplant Registry.

PubMed

Zhu, D; McCague, K; Lin, W; Rong, R; Xu, M; Chan, L; Zhu, T

2018-06-01

Kidney transplantation is limited by the shortage of donor kidneys. Donation after cardiac death (DCD) has been explored to alleviate this problem. To better understand the outcome of DCD kidney transplantation, we reanalyzed the Mycophenolic Renal Transplant (MORE) Registry. We compared delayed graft function (DGF), biopsy-proved acute rejection (BPAR), graft loss, and patient death between DCD and donation after brain death (DBD) kidney transplantations. Recipients were further stratified into depleting and nondepleting induction groups for exploratory analysis. There were 548 patients who received kidney transplants from deceased donor in the MORE Registry. Among them, 133 received grafts from DCD donors and 415 received from DBD donors. The incidence of DGF was 29.4% and 23.5% in the DCD group and the DBD group, respectively (P = .1812), and the incidence of BPAR at 12 months was 9.0% and 9.9% respectively (P = .7713). The 1-year graft loss rate in the DCD group was higher than that in the DBD group (7.5% vs 3.1%, P = .0283), and the 4-year graft loss rate and patient death rate were not significantly different between the 2 groups. The DCD kidney transplant group had acceptable short-term outcomes and good long-term outcomes as compared with the DBD kidney transplant group. Copyright © 2018 Elsevier Inc. All rights reserved.

YKL-40 Associates with Renal Recovery in Deceased Donor Kidney Transplantation

PubMed Central

Puthumana, Jeremy; Hall, Isaac E.; Reese, Peter P.; Schröppel, Bernd; Weng, Francis L.; Thiessen-Philbrook, Heather; Doshi, Mona D.; Rao, Veena; Lee, Chun Geun; Elias, Jack A.; Cantley, Lloyd G.

2017-01-01

Deceased donor kidneys with AKI are often discarded for fear of poor transplant outcomes. Donor biomarkers that predict post-transplant renal recovery could improve organ selection and reduce discard. We tested whether higher levels of donor urinary YKL-40, a repair phase protein, associate with improved recipient outcomes in a prospective cohort study involving deceased kidney donors from five organ procurement organizations. We measured urinary YKL-40 concentration in 1301 donors (111 had AKI, defined as doubling of serum creatinine) and ascertained outcomes in the corresponding 2435 recipients, 756 of whom experienced delayed graft function (DGF). Donors with AKI had higher urinary YKL-40 concentration (P<0.001) and acute tubular necrosis on procurement biopsies (P=0.05). In fully adjusted analyses, elevated donor urinary YKL-40 concentration associated with reduced risk of DGF in both recipients of AKI donor kidneys (adjusted relative risk, 0.51 [95% confidence interval (95% CI), 0.32 to 0.80] for highest versus lowest YKL-40 tertile) and recipients of non-AKI donor kidneys (adjusted relative risk, 0.79 [95% CI, 0.65 to 0.97]). Furthermore, in the event of DGF, elevated donor urinary YKL-40 concentration associated with higher 6-month eGFR (6.75 [95% CI, 1.49 to 12.02] ml/min per 1.73 m2) and lower risk of graft failure (adjusted hazard ratio, 0.50 [95% CI, 0.27 to 0.94]). These findings suggest that YKL-40 is produced in response to tubular injury and is independently associated with recovery from AKI and DGF. If ultimately validated as a prognostic biomarker, urinary YKL-40 should be considered in determining the suitability of donor kidneys for transplant. PMID:27451287

Increased resistin in brain dead organ donors is associated with delayed graft function after kidney transplantation

PubMed Central

2013-01-01

Introduction Resistin increases during several inflammatory diseases and after intracerebral bleeding or head trauma. Resistin activates the endothelium and may initiate an inflammatory response. No data are available on resistin in brain dead donors (DBD) that regularly manifest a pronounced inflammatory state. Methods We analyzed plasma resistin in 63 DBDs and correlated results with donor variables and the postoperative course following kidney transplantation using organs from these donors. Endocan and monocyte chemotactic protein (MCP)-1 were also studied. Twenty-six live kidney donors (LD) and the corresponding kidney transplantations were used as controls. Results DBDs had higher resistin (median/range 30.75 ng/ml, 5.41–173.6) than LD (7.71 ng/ml, 2.41–15.74, p < 0.0001). Resistin in DBD correlated with delayed graft function (DGF) in the kidney recipients (r = 0.321, p < 0.01); receiver operating characteristic curve revealed an area under the curve of 0.765 (95% confidence interval [CI] 0.648–0.881, p < 0.01) and a cut-off value for resistin of 25 ng/ml; MCP-1 and endocan were higher in DBDs (p < 0.0001) but did not correlate with DGF or acute rejection. No relationship was found between the studied molecules and the postoperative course of LD kidney transplants. Conclusions High resistin levels in the DBD before organ retrieval are associated with DGF after kidney transplantation. The resistin increase seems related to the inflammatory state after brain death but not to the cause of death. PMID:24070260

Expanded criteria donor and donation after circulatory death renal allografts in the West of Scotland: Their place in the kidney allocation process.

PubMed

Hesse, Kerrick; Aitken, Emma; Clancy, Marc; Vesey, Alex

2016-06-01

Due to the rising disparity between demand and availability, organs from expanded criteria donors (ECD) and donors after determination of circulatory death (DCD) are increasingly used. The purpose of this study was to report outcomes in recipients of ECD and DCD renal allografts from a single centre. A retrospective analysis from a single centre for all renal transplants performed between 2001 and 2010 inclusive was undertaken. SCD (standard criteria donor) and ECD organs were compared, as were DCD and DBD (donation after determination of brain stem death) organs. Baseline data and predefined standard transplant outcomes were collected and compared using appropriate statistical tests. P < 0.05 was defined as significant. 729 renal transplants were performed. Comparing ECD to SCD organs, there was a significant difference in graft survival between groups (logrank for trend, p = 0.032) with ECD organs doing worse than SCD organs. Short-term outcomes showed a similar disparity with a higher 1-year post-transplant creatinine and delayed graft function (DGF) rate in ECD grafts. Nevertheless, outcomes were still clinically acceptable. When comparing DCD to DBD organs, no such differences were apparent, with DCD organs appearing to perform at least as well as DBD organs. In our cohort, unlike some previous studies, DGF rates were similar in both DCD and DBD groups. Although ECD organs perform less well than SCD organs, outcomes are still acceptable and our results support their continuing use. When considering DCD organs, our data support the view that they should no longer be necessarily regarded as marginal grafts. Our low DGF rates are perhaps explained by local factors contributing to a short CIT. Copyright © 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Outcomes for primary kidney transplantation from donation after Citizens' death in China: a single center experience of 367 cases.

PubMed

Xue, Wujun; Tian, Puxun; Xiang, Heli; Ding, Xiaoming; Pan, Xiaoming; Yan, Hang; Hou, Jun; Feng, Xinshun; Liu, Linjuan; Ding, Chenguang; Tian, Xiaohui; Li, Yang; Zheng, Jin

2017-04-04

The cases of donation after brain death followed by circulatory death (DBCD) and donation after cardiac death (DCD) have been increased year by year in China. Further research is needed to understand in the outcomes and risk factors of delayed graft function (DGF) in order to minimize the risk of DGF and ameliorate its potential impact on long-term outcomes. This study was to explore the differences in outcomes between DBCD and DCD transplant and the main risk factors for DGF in DBCD. Retrospective analysis of the clinical data of 367donations after citizens' death kidney transplant procedures (donors and recipients) between July 2012 and August 2015 at our center. During the study period, the donation success rate was 25.3%. 164 cases of DBCD and 35 cases of DCD had been implemented and 367 kidneys were transplanted. The incidence of DGF in DBCD group were significantly lower than that of DCD group (12.0% vs. 27.0%, p = 0.002). The 1-year percent freedom from acute rejection (AR) was significantly higher in DBCD group compared with it of DCD group (94% vs. 82%, p = 0.036). Multivariate logistic regression analysis of the kidney transplants revealed that the high risk factors for DGF after renal transplantation in DBCD were history of hypertension (Odds Ratio [OR] = 5.88, 95% CI: 1.90 to 18.2, p = 0.002), low blood pressure (BP < 80 mmHg) (OR = 4.86, 95% CI: 1.58 to 14.9, p = 0.006) and serum creatinine of donor (OR = 1.09, 95% CI: 1.03 to 1.16, p = 0.003) before donation. The outcomes of DBCD could be better than DCD in DGF and AR. The main risk factors for DGF in DBCD kidney transplants are donors with a history of hypertension, low blood pressure, and serum creatinine of donor before donation.

Renal Resistance Trend During Hypothermic Machine Perfusion Is More Predictive of Postoperative Outcome Than Biopsy Score: Preliminary Experience in 35 Consecutive Kidney Transplantations.

PubMed

Bissolati, Massimiliano; Gazzetta, Paolo Giovanni; Caldara, Rossana; Guarneri, Giovanni; Adamenko, Olga; Giannone, Fabio; Mazza, Michele; Maggi, Giulia; Tomanin, Deborah; Rosati, Riccardo; Secchi, Antonio; Socci, Carlo

2018-03-30

Hypothermic machine perfusion (HPM) grants a better postoperative outcome in transplantation of organs procured from extended criteria donors (ECDs) and donors after cardiac death (DCD). So far, the only available parameter for outcome prediction concerning those organs is pretransplant biopsy score. The aim of this study is to evaluate whether renal resistance (RR) trend during HPM may be used as a predictive marker for post-transplantation outcome. From December 2015 to present, HMP has been systematically applied to all organs from ECDs and DCD. All grafts underwent pretransplantation biopsy evaluation using Karpinski's histological score. Only organs that reached RR value ≤1.0 within 3 hours of perfusion were transplanted. Single kidney transplantation (SKT) or double kidney transplantation (DKT) were performed according to biopsy score results. Sixty-five HMPs were performed (58 from ECDs and 7 from DCD/ECMO donors). Fifteen kidneys were insufficiently reconditioned (RR > 1) and were therefore discarded. Forty-nine kidneys were transplanted, divided between 21 SKT and 14 DKT. Overall primary nonfunction (PNF) and delayed graft function (DGF) rate were 2.9 and 17.1%, respectively. DGF were more common in kidneys from DCD (67 vs. 7%; P = 0.004). Biopsy score did not correlate with PNF/DGF rate (P = 0.870) and postoperative creatinine trend (P = 0.796). Recipients of kidneys that reached RR ≤ 1.0 within 1 hour of HMP had a lower PNF/DGF rate (11 vs. 44%; P = 0.033) and faster serum creatinine decrease (POD10 creatinine: 1.79 mg/dL vs. 4.33 mg/dL; P = 0.019). RR trend is more predictive of post-transplantation outcome than biopsy score. Hence, RR trend should be taken into account in the pretransplantation evaluation of the organs. © 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Laparoscopic sleeve gastrectomy improves renal transplant candidacy and posttransplant outcomes in morbidly obese patients.

PubMed

Kim, Y; Jung, A D; Dhar, V K; Tadros, J S; Schauer, D P; Smith, E P; Hanseman, D J; Cuffy, M C; Alloway, R R; Shields, A R; Shah, S A; Woodle, E S; Diwan, T S

2018-02-01

Morbid obesity is a barrier to kidney transplantation due to inferior outcomes, including higher rates of new-onset diabetes after transplantation (NODAT), delayed graft function (DGF), and graft failure. Laparoscopic sleeve gastrectomy (LSG) increases transplant eligibility by reducing BMI in kidney transplant candidates, but the effect of surgical weight loss on posttransplantation outcomes is unknown. Reviewing single-center medical records, we identified all patients who underwent LSG before kidney transplantation from 2011-2016 (n = 20). Post-LSG kidney recipients were compared with similar-BMI recipients who did not undergo LSG, using 2:1 direct matching for patient factors. McNemar's test and signed-rank test were used to compare groups. Among post-LSG patients, mean BMI ± standard deviation (SD) was 41.5 ± 4.4 kg/m 2 at initial encounter, which decreased to 32.3 ± 2.9 kg/m 2 prior to transplantation (P < .01). No complications, readmissions, or mortality occurred following LSG. After transplantation, one patient (5%) experienced DGF, and no patients experienced NODAT. Allograft and patient survival at 1-year posttransplantation was 100%. Compared with non-LSG patients, post-LSG recipients had lower rates of DGF (5% vs 20%) and renal dysfunction-related readmissions (10% vs 27.5%) (P < .05 each). Perioperative complications, allograft survival, and patient survival were similar between groups. These data suggest that morbidly obese patients with end-stage renal disease who undergo LSG to improve transplant candidacy, achieve excellent posttransplantation outcomes. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Ischaemia-reperfusion injury: a major protagonist in kidney transplantation.

PubMed

Ponticelli, Claudio

2014-06-01

Ischaemia-reperfusion injury (IRI) is a frequent event in kidney transplantation, particularly when the kidney comes from a deceased donor. The brain death is usually associated with generalized ischaemia due to a hyperactivity of the sympathetic system. In spite of this, most donors have profound hypotension and require administration of vasoconstrictor agents. Warm ischaemia after kidney vessels clamping and the cold ischaemia after refrigeration also reduce oxygen and nutrients supply to tissues. The reperfusion further aggravates the state of oxidation and inflammation created by ischaemia. IRI first attacks endothelial cells and tubular epithelial cells. The lesions may be so severe that they lead to acute kidney injury (AKI) and delayed graft function (DGF), which can impair the graft survival. The unfavourable impact of DGF is worse when DGF is associated with acute rejection. Another consequence of IRI is the activation of the innate immunity. Danger signals released by dying cells alarm Toll-like receptors that, through adapter molecules and a chain of kinases, transmit the signal to transcription factors which encode the genes regulating inflammatory cells and mediators. In the inflammatory environment, dendritic cells (DCs) intercept the antigen, migrate to lymph nodes and present the antigen to immunocompetent cells, so activating the adaptive immunity and favouring rejection. Attempts to prevent IRI include optimal management of donor and recipient. Calcium-channel blockers, l-arginine and N-acetylcysteine could obtain a small reduction in the incidence of post-transplant DGF. Fenoldopam, Atrial Natriuretic Peptide, Brain Natriuretic Peptide and Dopamine proved to be helpful in reducing the risk of AKI in experimental models, but there is no controlled evidence that these agents may be of benefit in preventing DGF in kidney transplant recipients. Other antioxidants have been successfully used in experimental models of AKI but only a few studies of poor quality have been made in clinical transplantation with a few of these agents and we still lack of unambiguous demonstration that pre-treatment with these antioxidants can attenuate the impact of IRI in kidney transplantation. Interference with the signals leading to activation of innate immunity, inactivation of complement or manipulation of DCs is a promising therapeutic option for the near future. © The Author 2013. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Kidney transplantation from deceased donors with elevated serum creatinine.

PubMed

Gallinat, Anja; Leerhoff, Sabine; Paul, Andreas; Molmenti, Ernesto P; Schulze, Maren; Witzke, Oliver; Sotiropoulos, Georgios C

2016-12-01

Elevated donor serum creatinine has been associated with inferior graft survival in kidney transplantation (KT). The aim of this study was to evaluate the impact of elevated donor serum creatinine on short and long-term outcomes and to determine possible ways to optimize the use of these organs. All kidney transplants from 01-2000 to 12-2012 with donor creatinine ≥ 2 mg/dl were considered. Risk factors for delayed graft function (DGF) were explored with uni- and multivariate regression analyses. Donor and recipient data were analyzed with uni- and multivariate cox proportional hazard analyses. Graft and patient survival were calculated using the Kaplan-Meier method. Seventy-eight patients were considered. Median recipient age and waiting time on dialysis were 53 years and 5.1 years, respectively. After a median follow-up of 6.2 years, 63 patients are alive. 1, 3, and 5-year graft and patient survival rates were 92, 89, and 89 % and 96, 93, and 89 %, respectively. Serum creatinine level at procurement and recipient's dialysis time prior to KT were predictors of DGF in multivariate analysis (p = 0.0164 and p = 0.0101, respectively). Charlson comorbidity score retained statistical significance by multivariate regression analysis for graft survival (p = 0.0321). Recipient age (p = 0.0035) was predictive of patient survival by multivariate analysis. Satisfactory long-term kidney transplant outcomes in the setting of elevated donor serum creatinine ≥2 mg/dl can be achieved when donor creatinine is <3.5 mg/dl, and the recipient has low comorbidities, is under 56 years of age, and remains in dialysis prior to KT for <6.8 years.

Prediction of acute renal allograft rejection in early post-transplantation period by soluble CD30.

PubMed

Dong, Wang; Shunliang, Yang; Weizhen, Wu; Qinghua, Wang; Zhangxin, Zeng; Jianming, Tan; He, Wang

2006-06-01

To evaluate the feasibility of serum sCD30 for prediction of acute graft rejection, we analyzed clinical data of 231 patients, whose serum levels of sCD30 were detected by ELISA before and after transplantation. They were divided into three groups: acute rejection group (AR, n = 49), uncomplicated course group (UC, n = 171) and delayed graft function group (DGF, n = 11). Preoperative sCD30 levels of three groups were 183 +/- 74, 177 +/- 82 and 168 +/- 53 U/ml, respectively (P = 0.82). Significant decrease of sCD30 was detected in three groups on day 5 and 10 post-transplantation respectively (52 +/- 30 and 9 +/- 5 U/ml respectively, P < 0.001). Compared with Group UC and DGF, patients of Group AR had higher sCD30 values on day 5 post-transplantation (92 +/- 27 U/ml vs. 41 +/- 20 U/ml and 48 +/- 18 U/ml, P < 0.001). However, sCD30 levels on day 10 post-transplantation were virtually similar in patients of three groups (P = 0.43). Receiver operating characteristic (ROC) curve demonstrated that sCD30 level on day 5 post-transplantation could differentiate patients who subsequently suffered acute allograft rejection from others (area under ROC curve 0.95). According to ROC curve, 65 U/ml may be the optimal operational cut-off level to predict impending graft rejection (specificity 91.8%, sensitivity 87.1%). Measurement of soluble CD30 on day 5 post-transplantation might offer a noninvasive means to recognize patients at risk of impending acute graft rejection during early post-transplantation period.

Impact of donor obesity and donation after cardiac death on outcomes after kidney transplantation.

PubMed

Ortiz, Jorge; Gregg, Austin; Wen, Xuerong; Karipineni, Farah; Kayler, Liise K

2012-01-01

The effect of donor body mass index (BMI) and donor type on kidney transplant outcomes has not been well studied. Scientific Registry of Transplant Recipients data on recipients of deceased-donor kidneys between 1997 and 2010 were reviewed. Donors were categorized by DCD status (DCD, 6932; non-DCD, 90,158) and BMI groups at 5 kg/m(2) increments: 18.5-24.9, 25-29.9, 30-34.9, 35-39.9, 40-44.9, and ≥ 45 kg/m(2) . The primary outcome, death-censored graft survival (DCGS), was adjusted for donor, recipient, and transplant characteristics. Among recipients of non-DCD kidneys, donor BMI was not associated with DCGS. Among DCD recipients, donor BMI was not associated with DCGS for donor BMI categories < 45 kg/m(2) ; however, donor BMI ≥ 45 kg/m(2) was independently associated with DCGS compared to BMI of 20-24.9 kg/m(2) (adjusted hazard ratio, 1.84; 95% CI, 1.23, 2.74). The adjusted odds of delayed graft function (DGF) was greater for each level of BMI above reference for both DCD and non-DCD groups. There was no association of donor BMI with one-yr acute rejection for either type of donor. Although BMI is associated with DGF, long-term graft survival is not affected except in the combination of DCD with extreme donor BMI ≥ 45. © 2012 John Wiley & Sons A/S.

The effect of the use of a TNF-alpha inhibitor in hypothermic machine perfusion on kidney function after transplantation.

PubMed

Diuwe, Piotr; Domagala, Piotr; Durlik, Magdalena; Trzebicki, Janusz; Chmura, Andrzej; Kwiatkowski, Artur

2017-08-01

One of the most important problems in transplantation medicine is the ischemia/reperfusion injury of the organs to be transplanted. The aim of the present study was to assess the effect of tumor necrosis factor-alpha (TNF-alpha) inhibitor etanercept on the machine perfusion hypothermia of renal allograft kidney function and organ perfusion. No statistically significant differences were found in the impact of the applied intervention on kidney machine perfusion during which the average flow and vascular resistance were evaluated. There were no statistically significant differences in the occurrence of delayed graft function (DGF). Fewer events in patients who received a kidney from the etanercept treated Group A compared to the patients who received a kidney from the control Group B were observed when comparing the functional DGF and occurrence of acute rejection episodes, however, there was no statistically significant difference. In summary, no effect of treatment with etanercept an inhibitor of TNF-alpha in a hypothermic machine perfusion on renal allograft renal survival and its perfusion were detected in this study. However, treatment of the isolated organ may be important for the future of transplantation medicine. Copyright © 2017 Elsevier Inc. All rights reserved.

Dual kidney transplants from adult marginal donors successfully expand the limited deceased donor organ pool.

PubMed

Stratta, Robert J; Farney, Alan C; Orlando, Giuseppe; Farooq, Umar; Al-Shraideh, Yousef; Palanisamy, Amudha; Reeves-Daniel, Amber; Doares, William; Kaczmorski, Scott; Gautreaux, Michael D; Iskandar, Samy S; Hairston, Gloria; Brim, Elizabeth; Mangus, Margaret; El-Hennawy, Hany; Khan, Muhammad; Rogers, Jeffrey

2016-04-01

The need to expand the organ donor pool remains a formidable challenge in kidney transplantation (KT). The use of expanded criteria donors (ECDs) represents one approach, but kidney discard rates are high because of concerns regarding overall quality. Dual KT (DKT) may reduce organ discard and optimize the use of kidneys from marginal donors. We conducted a single-center retrospective review of outcomes in adult recipients of DKTs from adult marginal deceased donors (DD) defined by limited renal functional capacity. If the calculated creatinine clearance in an adult DD was <65 mL/min, then the kidneys were transplanted as a DKT. Over 11.5 yr, 72 DKTS were performed including 45 from ECDs, 17 from donation after cardiac death (DCD) donors, and 10 from standard criteria donors (SCD). Mean adult DD and recipient ages were both 60 yr, including 29 DDs and 26 recipients ≥65 yr of age. Mean pre-DKT waiting and dialysis vintage times were 12 months and 25 months, respectively. Actual patient and graft survival rates were 84.7% and 70.8%, respectively, with a mean follow-up of 58 months. One yr and death-censored graft survival rates were 90% and 80%, respectively. Outcomes did not differ by DD category, recipient age, or presence of delayed graft function (DGF). Eleven patients died at a mean of 32 months post-DKT (eight with functioning grafts) and 13 other patients experienced graft losses at a mean of 33 months. The incidence of DGF was 25%; there were two cases (2.8%) of primary non-function. Mean length of initial hospital stay was 7.2 d. Mean serum creatinine and glomerular filtration rate levels at 12 and 24 months were 1.5 and 53 and 1.5 mg/dL and 51 mL/min/1.73 m(2) , respectively. DKT graft survival and function were superior to concurrent single ECD and similar to concurrent SCD KTs. Two patients underwent successful kidney retransplantation, so the dialysis-free rate in surviving patients was 87%. The proportion of total renal function transplanted from adult DD to DKT recipients was 77% compared to 56% for patients receiving single KTs. Dual kidney transplantation using kidneys from adult marginal DDs that otherwise might be discarded offer a viable option to counteract the growing shortage of acceptable single kidneys. Excellent medium-term outcomes can be achieved and waiting times can be reduced in a predominantly older recipient population. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Impact of cold ischemia time on the outcomes of kidneys with Kidney Donor Profile Index ≥85%: mate kidney analysis - a retrospective study.

PubMed

Sampaio, Marcelo S; Chopra, Bhavna; Tang, Amy; Sureshkumar, Kalathil K

2018-07-01

The new kidney allocation system recommends local and regional sharing of deceased donor kidneys (DDK) with 86-100% Kidney Donor Profile Index (KDPI) to minimize discard. Regional sharing can increase cold ischemia time (CIT) which may negatively impact transplant outcomes. Using a same donor mate kidney model, we aimed to define a CIT that should be targeted to optimize outcomes. Using Organ Procurement and Transplant Network/United Network for Organ Sharing database, we identified recipients of DDK from 2000 to 2013 with ≥85% KDPI. From this cohort, three groups of mate kidney recipients were identified based on CIT: group 1 (≥24 vs. ≥12 to <24 h), group 2 (≥24 vs. <12 h), and group 3 (≥12 to <24 vs. <12 h). Adjusted delayed graft function (DGF), and graft and patient survivals were compared for mate kidneys. DGF risk was significantly lower for patients with CIT <12 vs. ≥24 h in group 2 (adjusted OR: 0.25, 95% CI: 0.12-0.57, P < 0.001) while trending lower for CIT ≥12 to <24 vs. ≥24 h in group 1 (adjusted OR: 0.78, 95% CI: 0.59-1.03, P = 0.08) and CIT <12 vs. ≥12 to <24 h in group 3 (adjusted OR: 0.74, 95% CI: 0.55-1.0, P = 0.05). Adjusted graft and patient survivals were similar between mate kidneys in all groups. Minimizing CIT improves outcomes with regional sharing of marginal kidneys. © 2018 Steunstichting ESOT.

Renal Allograft Outcome After Simultaneous Heart and Kidney Transplantation.

PubMed

Grupper, Avishay; Grupper, Ayelet; Daly, Richard C; Pereira, Naveen L; Hathcock, Matthew A; Kremers, Walter K; Cosio, Fernando G; Edwards, Brooks S; Kushwaha, Sudhir S

2017-08-01

Chronic kidney disease frequently accompanies end-stage heart failure and may result in consideration of simultaneous heart and kidney transplantation (SHKT). In recent years, there has been a significant increase in SHKT. This single-center cohort consisted of 35 patients who underwent SHKT during 1996 to 2015. The aim of this study was to review factors that may predict better long-term outcome after SKHT. Thirteen patients (37%) had delayed graft function (DGF) after transplant (defined as the need for dialysis during the first 7 days after transplant), which was significantly associated with mechanical circulatory support device therapy and high right ventricular systolic pressure before transplant. Most of the recipients had glomerular filtration rate (GFR) ≥50 ml/min/1.73 m 2 at 1 and 3 years after transplant (21 of 26 [81%] and 20 of 21 [95%], respectively). Higher donor age was associated with reduced 1-year GFR (p = 0.017), and higher recipient pretransplant body mass index was associated with reduced 3-year GFR (p = 0.008). There was a significant association between DGF and reduced median GFR at 1 and 3 years after transplant (p <0.005). Patient survival rates at 6 months, 1, and 3 years after transplant were 97%, 91%, and 86% respectively. In conclusions, our data support good outcomes after SHKT. Mechanical circulatory support device therapy and pulmonary hypertension before transplant are associated with DGF, which is a risk factor for poor long-term renal allograft function. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimized donor management and organ preservation before kidney transplantation.

PubMed

Mundt, Heiko M; Yard, Benito A; Krämer, Bernhard K; Benck, Urs; Schnülle, Peter

2016-09-01

Kidney transplantation is a major medical improvement for patients with end-stage renal disease, but organ shortage limits its widespread use. As a consequence, the proportion of grafts procured from extended criteria donors (ECD) has increased considerably, but this comes along with increased rates of delayed graft function (DGF) and a higher incidence of immune-mediated rejection that limits organ and patient survival. Furthermore, most grafts are derived from brain dead organ donors, but the unphysiological state of brain death is associated with significant metabolic, hemodynamic, and pro-inflammatory changes, which further compromise patient and graft survival. Thus, donor interventions to preserve graft quality are fundamental to improve long-term transplantation outcome, but interventions must not harm other potentially transplantable grafts. Several donor pretreatment strategies have provided encouraging results in animal models, but evidence from human studies is sparse, as most clinical evidence is derived from single-center or nonrandomized trials. Furthermore, ethical matters have to be considered especially concerning consent from donors, donor families, and transplant recipients to research in the field of donor treatment. This review provides an overview of clinically proven and promising preclinical strategies of donor treatment to optimize long-term results after kidney transplantation. © 2015 Steunstichting ESOT.

Intermediate-Term Outcomes With Expanded Criteria Deceased Donors in Kidney Transplantation

PubMed Central

Stratta, Robert J.; Rohr, Michael S.; Sundberg, Aimee K.; Farney, Alan C.; Hartmann, Erica L.; Moore, Phillip S.; Rogers, Jeffrey; Iskandar, Samy S.; Gautreaux, Michael D.; Kiger, David F.; Doares, William; Anderson, Teresa K.; Hairston, Gloria; Adams, Patricia L.

2006-01-01

Objective: To compare intermediate-term outcomes in adult recipients of expanded criteria (ECD) versus concurrent standard criteria (SCD) deceased donor kidney transplants at a single center using a standardized approach. Summary Background Data: Expanded criteria donors (ECDs) are a source of kidneys that increase the donor organ pool, but the value of transplanting these kidneys has been questioned because of concerns regarding diminished survival and predicted poorer intermediate-term outcomes. Methods: Over a 47-month period, we performed 244 deceased donor kidney transplants into adult recipients, including 143 from SCDs and 101 from ECDs. Management algorithms were implemented to preserve nephron function, and recipient selection for an ECD kidney transplant was based on low immunologic risk. All patients received depleting antibody induction in combination with tacrolimus and mycophenolate mofetil. A total of 188 patients (77%) had at least a 1-year follow-up. Results: ECDs were older, had a higher BMI, had an increased incidence of cerebrovascular brain death and preexisting donor hypertension, and had a lower estimated creatinine clearance (CrCl, all P < 0.01) compared with SCDs. Cold ischemic times were similar between groups, but more ECD kidneys were preserved with pulsatile perfusion (P < 0.01). ECD kidney recipients were older, less sensitized, had a lower BMI, had fewer 0-antigen mismatches, and had a shorter waiting time (all P < 0.01) compared with SCD kidney recipients. Actual patient (93%) and kidney graft (83%) survival rates were similar between groups with a mean follow-up of 24 months. The rates of delayed graft function (DGF), acute rejection, readmissions, operative complications, major infections, and resource utilization were comparable between groups. Renal function followed longitudinally was consistently better in SCD patients (P < 0.05). Black recipients had higher rates of DGF, acute rejection, and graft loss (P < 0.05), but the effects were less pronounced in the ECD group. Conclusions: By appropriate donor and recipient profiling and the use of management algorithms to project and protect renal function, excellent intermediate-term outcomes can be achieved with ECD kidney transplants that are comparable to SCD kidney transplants. PMID:16632993

Early renal function recovery and long-term graft survival in kidney transplantation.

PubMed

Wan, Susan S; Cantarovich, Marcelo; Mucsi, Istvan; Baran, Dana; Paraskevas, Steven; Tchervenkov, Jean

2016-05-01

Following kidney transplantation (KTx), renal function improves gradually until a baseline eGFR is achieved. Whether or not a recipient achieves the best-predicted eGFR after KTx may have important implications for immediate patient management, as well as for long-term graft survival. The aim of this cohort study was to calculate the renal function recovery (RFR) based on recipient and donor eGFR and to evaluate the association between RFR and long-term death-censored graft failure (DCGF). We studied 790 KTx recipients between January 1990 and August 2014. The last donor SCr prior to organ procurement was used to estimate donor GFR. Recipient eGFR was calculated using the average of the best three SCr values observed during the first 3 months post-KTx. RFR was defined as the ratio of recipient eGFR to half the donor eGFR. 53% of recipients had an RFR ≥1. There were 127 death-censored graft failures (16%). Recipients with an RFR ≥1 had less DCGF compared with those with an RFR <1 (HR 0.56; 95% CI 0.37-0.85; P = 0.006). Transplant era, acute rejection, ECD and DGF were also significant determinants of graft failure. Early recovery of predicted eGFR based on donor eGFR is associated with less DCGF after KTx. © 2016 Steunstichting ESOT.

Outcome of organs procured from donors on extracorporeal membrane oxygenation support: an analysis of kidney and liver allograft data.

PubMed

Carter, Timothy; Bodzin, Adam S; Hirose, Hitoshi; West, Sharon; Hasz, Richard; Maley, Warren R; Cavarocchi, Nicholas C

2014-07-01

Extracorporeal membrane oxygenation has become rescue therapy for adults with overwhelming cardiac and/or respiratory failure. Not all patients are saved, creating a new cohort of potential organ donors. This study examines the outcomes of liver and kidney allografts procured from donors on extracorporeal membrane oxygenation (ECMO). A retrospective review was conducted through the local organ procurement organization. Donors on ECMO prior to notification were classified into donation after brain death (DBD) and donation after cardiac death (DCD). We compared short-term outcome data against published standards. Between 1995 and 2012, 97 organs were procured from 41 donors supported on ECMO. There were 68 kidneys donated, 51 were transplanted and 17 discarded. Excluding extended criteria donors, 29 DBD and 13 DCD kidneys were transplanted from donors supported on ECMO. Delayed graft function occurred in 34% of DBD kidneys and 38% of DCD kidneys. Kidney allograft survival at one yr was 93%. Twenty-four livers were procured, nine discarded, and 15 transplanted. Ninety-three percent of liver transplant recipients were alive with graft function at one yr. Donation after brain death kidneys procured from donors on ECMO perform similarly to non-ECMO organs with regard to delayed graft function (DGF), one-yr graft survival and function. Livers from ECMO donors have a higher discard rate than non-ECMO donors, but function similarly at six months and one yr. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Validating Early Post–Transplant Outcomes Reported for Recipients of Deceased Donor Kidney Transplants

PubMed Central

Potluri, Vishnu S.; Hall, Isaac E.; Ficek, Joseph; Doshi, Mona D.; Butrymowicz, Isabel; Weng, Francis L.; Schröppel, Bernd; Thiessen-Philbrook, Heather; Reese, Peter P.

2016-01-01

Background and objectives Data reported to the Organ Procurement and Transplantation Network (OPTN) are used in kidney transplant research, policy development, and assessment of center quality, but the accuracy of early post–transplant outcome measures is unknown. Design, setting, participants, & measurements The Deceased Donor Study (DDS) is a prospective cohort study at five transplant centers. Research coordinators manually abstracted data from electronic records for 557 adults who underwent deceased donor kidney transplantation between April of 2010 and November of 2013. We compared the post-transplant outcomes of delayed graft function (DGF; defined as dialysis in the first post–transplant week), acute rejection, and post–transplant serum creatinine reported to the OPTN with data collected for the DDS. Results Median kidney donor risk index was 1.22 (interquartile range [IQR], 0.97–1.53). Median recipient age was 55 (IQR, 46–63) years old, 63% were men, and 47% were black; 93% had received dialysis before transplant. Using DDS data as the gold standard, we found that pretransplant dialysis was not reported to the OPTN in only 11 (2%) instances. DGF in OPTN data had a sensitivity of 89% (95% confidence interval [95% CI], 84% to 93%) and specificity of 98% (95% CI, 96% to 99%). Surprisingly, the OPTN data accurately identified acute allograft rejection in only 20 of 47 instances (n=488; sensitivity of 43%; 95% CI, 17% to 73%). Across participating centers, sensitivity of acute rejection varied widely from 23% to 100%, whereas specificity was uniformly high (92%–100%). Six-month serum creatinine values in DDS and OPTN data had high concordance (n=490; Lin concordance correlation =0.90; 95% CI, 0.88 to 0.92). Conclusions OPTN outcomes for recipients of deceased donor kidney transplants have high validity for DGF and 6-month allograft function but lack sensitivity in detecting rejection. Future studies using OPTN data may consider focusing on allograft function at 6 months as a useful outcome. PMID:26668026

Cardiac output-based fluid optimization for kidney transplant recipients: a proof-of-concept trial.

PubMed

Corbella, Davide; Toppin, Patrick Jason; Ghanekar, Anand; Ayach, Nour; Schiff, Jeffery; Van Rensburg, Adrian; McCluskey, Stuart A

2018-04-10

Intravenous fluid management for deceased donor kidney transplantation is an important, modifiable risk factor for delayed graft function (DGF). The primary objective of this study was to determine if goal-directed fluid therapy using esophageal Doppler monitoring (EDM) to optimize stroke volume (SV) would alter the amount of fluid given. This randomized, proof-of-concept trial enrolled 50 deceased donor renal transplant recipients. Data collected included patient characteristics, fluid administration, hemodynamics, and complications. The EDM was used to optimize SV in the EDM group. In the control group, fluid management followed the current standard of practice. The groups were compared for the primary outcome of total intraoperative fluid administered. There was no difference in the mean (standard deviation) volume of intraoperative fluid administered to the 24 control and 26 EDM patients [2,307 (750) mL vs 2,675 (842) mL, respectively; mean difference, 368 mL; 95% confidence interval (CI), - 87 to + 823; P = 0.11]. The incidence of complications in the control and EDM groups was similar (15/24 vs 17/26, respectively; P = 0.99), as was the incidence of delayed graft failure (8/24 vs 11/26, respectively; P = 0.36). Goal-directed fluid therapy did not alter the volume of fluid administered or the incidence of complications. This proof-of-concept trial provides needed data for conducting a larger trial to determine the influence of fluid therapy on the incidence in DGF in deceased donor kidney transplantation. www.clinicaltrials.gov (NCT02512731). Registered 31 July 2015.

Expanded criteria donor kidneys for younger recipients: acceptable outcomes.

PubMed

Goplani, K R; Kute, V B; Vanikar, A V; Shah, P R; Gumber, M R; Patel, H V; Modi, P R; Trivedi, H L

2010-12-01

European senior programme (ESP) is well known for acceptable outcomes using expanded criteria donor (ECD) kidneys from donors older than 65 years for recipients older than 65 years. The incidence of end-stage renal disease (ESRD) is 229/million in India with a mean age of 45 years. We performed a retrospective analysis of transplantation of ECD versus standard criteria donor (SCD) kidneys into younger recipients. Forty-three ECD transplantations among 158 deceased donor organ transplantation (DDOT) were performed between January 2006 and December 2009. Among 43 transplantation from 30 donors, 14 were dual kidney transplantations (DKT) performed based upon biopsy evaluation. All recipients received thymoglobulin (rATG) induction followed by immunosuppression with a steroid, mycophenolate mofetil (MMF), and a calcineurin inhibitor. Statistical analysis used chi-square test and unpaired Student t test. Kaplan-Meier curves were used for survival analysis. For ECD the mean donor age was 64 ± 11 years. Cerebrovascular accidents (CVA) were the cause of death among 60% of donors, 73.13% of whom were hypertensive and 23.13% diabetic. Mean DKT donor age was 75 ± 9.17 years versus 60 ± 8.0 years for single kidney transplantation (SKT). Mean recipient age of DKT versus SKT was 44 ± 12.4 years versus 43 ± 14 years. Mean serum creatinine (SCr; mg/dL) of SKT patients was 1.64 ± 0.75 versus 1.68 ± 0.46 in DKT. Mean follow-up was 455 ± 352 days. Mean SCr of 43 ECD recipients of mean age, 43.4 ± 14.2 years was 1.61 ± 0.61 mg/dL. Among 43 recipients, 23.25% were diabetic, 41.86% displayed delayed graft function (DGF), and 23.25% experienced biopsy-proven acute rejection (BPAR). Patient survival rate was 72.09% and graft survival rate was 67.44%. For SCD transplantations (n = 115), the mean donor age was 36 ± 14 years and recipient mean age was 32.8 ± 14.07 years. Mean SCr was 1.32 ± 0.46 mg/dL with 26.95% recipients displaying DGF, whereas 20.86% had BPAR. In the SCD group the patient survival rate was 79.13% and the graft survival rate was 72.17%. Thus, although the ECD group showed poor graft function (P = .042), they had acceptable patient and graft survivals (P = .34 and P = .56, respectively). Because of the organ shortage, DDOT using ECD transplants for younger recipients is a feasible option with acceptable outcomes. Copyright © 2010 Elsevier Inc. All rights reserved.

Dyadic Green's function of an eccentrically stratified sphere.

PubMed

Moneda, Angela P; Chrissoulidis, Dimitrios P

2014-03-01

The electric dyadic Green's function (dGf) of an eccentrically stratified sphere is built by use of the superposition principle, dyadic algebra, and the addition theorem of vector spherical harmonics. The end result of the analytical formulation is a set of linear equations for the unknown vector wave amplitudes of the dGf. The unknowns are calculated by truncation of the infinite sums and matrix inversion. The theory is exact, as no simplifying assumptions are required in any one of the analytical steps leading to the dGf, and it is general in the sense that any number, position, size, and electrical properties can be considered for the layers of the sphere. The point source can be placed outside of or in any lossless part of the sphere. Energy conservation, reciprocity, and other checks verify that the dGf is correct. A numerical application is made to a stratified sphere made of gold and glass, which operates as a lens.

Regional perfusion by extracorporeal membrane oxygenation of abdominal organs from donors after circulatory death: a systematic review.

PubMed

Shapey, Iestyn M; Muiesan, Paolo

2013-12-01

Organs from donors after circulatory death (DCDs) are particularly susceptible to the effects of warm ischemia injury. Regional perfusion (RP) by extracorporeal membrane oxygenation (ECMO) is increasingly being advocated as a useful remedy to the effects of ischemia/reperfusion injury, and it has been reported to enable the transplantation of organs from donors previously deemed unsuitable. The MEDLINE, Embase, and Cochrane databases were searched, and articles published between 1997 and 2013 were obtained. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two hundred ten articles were identified, and 11 were eligible for inclusion. Four hundred eighty-two kidneys and 79 livers were transplanted from regional perfusion-supported donor after circulatory death (RP-DCD) sources. One-year graft survival was lower with uncontrolled RP-DCD liver transplantation, whereas 1-year patient survival was similar. Primary nonfunction and ischemic cholangiopathy were significantly more frequent with RP-DCDs versus donors after brain death (DBDs), but there was no difference in postoperative mortality between the 2 groups. The 1-year patient and graft survival rates for RP-DCD kidney transplantation were better than the rates with standard DCDs and were comparable to, if not better than, the rates with DBDs. At experienced centers, delayed graft function (DGF) for kidney transplantation from RP-DCDs was much less frequent in comparison with all other donor types. In conclusion, RP aids the recovery of DCD organs from ischemic injury and enables transplantation with acceptable survival. RP may help to increase the donor pool, but its benefits must still be balanced with the recognition of significantly higher rates of complications in liver transplantation. In kidney transplantation, significant reductions in DGF can be obtained with RP, and there are potentially important implications for long-term outcomes. Significant ethicolegal issues exist, and they are preventing a worldwide consensus on optimum RP protocols and an accurate appreciation of outcomes. © 2013 American Association for the Study of Liver Diseases.

Perioperative Desensitization Improves Outcomes Among Crossmatch Positive Recipients of Deceased Donor Renal Transplants.

PubMed

Sharma, Amit; King, Anne; Kumar, Dhiren; Behnke, Martha; McDougan, Felecia; Kimball, Pamela M

2016-06-01

Graft failure due to chronic rejection is greater among renal transplant patients with donor-specific antibody (DSA) than among DSA-free patients. For patients dependent on deceased donor transplantation, preoperative desensitization to eliminate DSAs may be impractical. We speculated that perioperative desensitization might eliminate preexisting DSAs and prevent de novo DSAs and improve graft outcomes. We report that brief perioperative desensitization using either intravenous immunoglobulin (IVIG) or plasmapheresis/IVIG (PP/IVIG) treatment improves clinical outcomes among patients with positive crossmatches. Immediately following deceased donor transplantation, 235 renal recipients were assigned points for PRA and flow crossmatches (FCXM): delayed graft function (DGF) ≤ 1 point received standard therapy; 2 points received high-dose IVIG; and ≥3 points received PP/IVIG. The DSAs were serially monitored by single antigen bead luminex for 1 year. Five-year clinical outcomes were determined from the chart review. All desensitized patients had preoperatively positive FCXM with DSA. Rejection was more common (P < .05) among desensitized than nonsensitized groups. However, overall graft survivals were similar between the groups (P = not significant) and superior to historic untreated patients (P < .05). Treatment with PP/IVIG more effectively eliminated preexisting DSAs (67% vs 33%, P < 0.05) than IVIG, but neither regimen prevented de novo formation of DSA (20%, P = not significant). Graft survival was >90% in all desensitizated patients with DSA elimination as well as PP/IVIG patients with residual DSA. In contrast, IVIG patients with persistent DSA had poorer graft survival (45%, P < .05). Preemptive perioperative desensitization improved overall graft survival of sensitized patients compared to historic untreated patients. Plasmapheresis/IVIG had greater impact on DSA eradication and graft survival than IVIG alone. © 2016, NATCO.

Dyadic Green's function of a cluster of spheres.

PubMed

Moneda, Angela P; Chrissoulidis, Dimitrios P

2007-11-01

The electric dyadic Green's function (dGf) of a cluster of spheres is obtained by application of the superposition principle, dyadic algebra, and the indirect mode-matching method. The analysis results in a set of linear equations for the unknown, vector, wave amplitudes of the dGf; that set is solved by truncation and matrix inversion. The theory is exact in the sense that no simplifying assumptions are made in the analytical steps leading to the dGf, and it is general in the sense that any number, position, size and electrical properties can be considered for the spheres that cluster together. The point source can be anywhere, even within one of the spheres. Energy conservation, reciprocity, and other tests prove that this solution is correct. Numerical results are presented for an electric Hertz dipole radiating in the presence of an array of rexolite spheres, which manifests lensing and beam-forming capabilities.

Association between Delayed graft function (DGF) biomarkers and long-term outcomes after living donor kidney transplantation.

PubMed

Sahraei, Zahra; Mehdizadeh, Mona; Salamzadeh, Jamshid; Nafar, Mohsen; Eshraghi, Azadeh

2018-05-21

The Association between preoperative Urine Neutrophil Gelatinase-associated Lipocalin (uNGAL) and interlukin-18 (uIL-18) with poor 1-year allograft function has been shown in deceased-donor kidney transplant recipients previously, and also these markers could predict 3-month allograft function. However, it is unknown whether there is any association between these postoperative biomarkers with important recipient outcomes beyond this time in live-donor transplants. NGAL and IL-18 four and 24 hours were measured in live-donor kidney transplant recipients after transplantation. The relationships between changes in these markers with clinical outcomes as well as kidney function were examined at 1 month and 2 years. Also, the association between delayed graft function with clinical outcome and serum creatinine (SrCr) were evaluated during this period. The Mean age for kidney recipients was 23.9 years. There was significant interaction between uNGAL 24 hr (pvalue=0.01) and uIL-18 four and 24 hr after transplantation (pvalue=0.04, 0.03; respectively) with patients' outcome after 1 month and changes in uNGAL with outcomes after 2 years (pvalue= 0.04). Changes in urine NGAL postoperative is associated with worse outcome 2 years after kidney transplantation, suggesting its potential role for identifying patients that are at high risk for diminished allograft function, outcome and survival. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Kidney transplantation outcomes in African-, Hispanic- and Caucasian-Americans with lupus.

PubMed

Contreras, G; Mattiazzi, A; Schultz, D R; Guerra, G; Ladino, M; Ortega, L M; Garcia-Estrada, M; Ramadugu, P; Gupta, C; Kupin, W L; Roth, D

2012-01-01

African-American recipients of kidney transplants with lupus have high allograft failure risk. We studied their risk adjusting for: (1) socio-demographic factors: donor age, gender and race-ethnicity; recipient age, gender, education and insurance; donor-recipient race-ethnicity match; (2) immunologic factors: donor type, panel reactive antibodies, HLA mismatch, ABO blood type compatibility, pre-transplant dialysis, cytomegalovirus risk and delayed graft function (DGF); (3) rejection and recurrent lupus nephritis (RLN). Two thousand four hundred and six African-, 1132 Hispanic-, and 2878 Caucasian-Americans were followed for 12 years after transplantation. African- versus Hispanic- and Caucasian-Americans received more kidneys from deceased donors (71.6%, 57.3% and 55.1%) with higher two HLA loci mismatches for HLA-A (50%, 39.6% and 32.4%), HLA-B (52%, 42.8% and 35.6%) and HLA-DR (30%, 24.5% and 21.1%). They developed more DGF (19.5%, 13.6% and 13.4%). More African- versus Hispanic- and Caucasian-Americans developed rejection (41.7%, 27.6% and 35.9%) and RLN (3.2, 1.8 and 1.8%). 852 African-, 265 Hispanic-, and 747 Caucasian-Americans had allograft failure (p < 0.0001). After adjusting for transplant era, socio-demographic-immunologic differences, rejection and RLN, the increased hazard ratio for allograft failure of African- compared with Caucasian-Americans became non-significant (1.26 [95% confidence interval 0.78-2.04]). African-Americans with lupus have high prevalence of risk factors for allograft failure that can explain poor outcomes.

Optical Coherence Tomography in Kidney Transplantation

NASA Astrophysics Data System (ADS)

Andrews, Peter M.; Wierwille, Jeremiah; Chen, Yu

End-stage renal disease (ESRD) is associated with both high mortality rates and an enormous economic burden [1]. The preferred treatment option for ESRD that can extend patients' lives and improve their quality of life is kidney transplantation. However, organ shortages continue to pose a major problem in kidney transplantation. Most kidneys for transplantation come from heart-beating cadavers. Although non-heart-beating cadavers represent a potentially large pool of donor kidneys, these kidneys are not often used due to the unknown extent of damage to the renal tubules (i.e., acute tubular necrosis or "ATN") induced by ischemia (i.e., lack of blood flow). Also, ischemic insult suffered by kidneys awaiting transplantation frequently causes ATN that leads to varying degrees of delayed graft function (DGF) after transplantation. Finally, ATN represents a significant risk for eventual graft and patient survival [2, 3] and can be difficult to discern from rejection. In present clinical practice, there is no reliable real-time test to determine the viability of donor kidneys and whether or not donor kidneys might exhibit ATN. Therefore, there is a critical need for an objective and reliable real-time test to predict ATN to use these organs safely and utilize the donor pool optimally. In this review, we provided preliminary data indicating that OCT can be used to predict the post-transplant function of kidneys used in transplantation.

Impact of mycophenolate mofetil dose posttransplantation on 12-month renal function: analysis of the MOST database.

PubMed

Salvadori, M; Bock, A; Chapman, J; Dussol, B; Fritsche, L; Kliem, V; Lebranchu, Y; Oppenheimer, F; Pohanka, E; Tufveson, G; Rosati, A; Puig, X; Corbetta, G

2005-01-01

Mycophenolate mofetil (MMF) has greatly reduced the risk of acute rejection episodes (ARE) after renal transplantation, but dose reductions/withdrawals could jeopardize long-term results. The MOST database of "de novo" patients treated with MMF at month 1 and functioning grafts at month 12 were divided into 2 groups: groups 1, 2 g MMF at month 1 and month 12; and group 2, 2 g MMF at month 1 but MMF <2 g at month 12 to evaluate renal function glonerular filtration rate (GFR). In this study, 1136 patients were receiving 2 g MMF at month 1. On month 12, 645 were on 2 g (56.8%, group 1) and 431 were on <2 g (43.2%, group 2). Group 1 included younger recipients of younger donors with fewer patients with delayed graft function (DGF). Group 1 showed more ARE during month 1 and more patients who received induction. Mean Neoral daily doses at month 1/month 12 were 5.3/3.0 and 5.3/3.1 mg/kg in group 1 and group 2, respectively (P = .05 at month 12). GFR in group 1 and group 2 were 59.06 (CI 57.10-60.60) and 53.81 (CI 52-55.7) at month 1 (P < .001); 63.7 (CI 62.1-65.30) and 55.9 (CI 54.1-57.7) mL/min*1.73 m(2) at month 12 (P < .001). The mean increases in GFR between month 1 and month 12 were 4.64 and 1.94 mL/min*1.73 m(2), respectively (P < .05). A multivariate analysis also included 795 patients from the "maintenance" patient database with retrospective detailed information. The following parameters were highly predictive for good renal function at month 12: donor age younger than 60 years, recipient age younger than 60 years, immediate graft function, 12-month MMF dose = 2 g, absence of CMV infection, and 12-month Neoral dose <3 mg/kg/d. Maintenance of MMF dose at 2 g/d during the first year appears to facilitate the attainment of optimal renal function at 12-months after kidney transplantation.

Leukocyte and platelet depletion improves blood flow and function in a renal transplant model.

PubMed

Yates, Phillip J; Hosgood, Sarah A; Nicholson, Michael L

2012-01-01

Donation after cardiac death (DCD) donors are an important source of organs for transplantation. Due to warm and cold ischemic injury, DCD kidneys undergo a significant reperfusion insult when transplanted. This is manifested clinically as a high incidence of delayed graft function (DGF) and primary non-function (PNF). The importance of leukocytes in the generation of reperfusion injury is pivotal. Using an ex vivo porcine model of kidney transplantation, the effects of reperfusion with leukocyte and platelet depleted blood (LDB) and whole blood (WB) on renal blood flow and function were compared. Hemodynamic measurements were recorded, and biochemical, hematological, and histologic samples taken at set time-points. Reperfusion with LDB improved renal blood flow significantly compared with WB reperfusion. In addition, there was a significant improvement in creatinine clearance and renal oxygen consumption, but not fractional excretion of sodium, acid-base homeostasis, urinary nitric oxide (NO), or 8-isoprostane levels. This study represents a good model for the initial reperfusion period in renal transplantation. Improvement in only some functional markers and neither urinary NO nor 8-isoprostane levels indicates that improved blood flow alone is not sufficient to reverse the severe ischemic insult endured by DCD kidneys. Copyright © 2012 Elsevier Inc. All rights reserved.

Dual kidney transplantation as a strategy to use expanded criteria donors: a systematic review.

PubMed

Montero, Nuria; Redondo-Pachón, Dolores; Pérez-Sáez, María José; Crespo, Marta; Cruzado, Josep M; Pascual, Julio

2018-03-27

The objective of this review was to assess whether dual kidney transplantation (DKT) is better than single KT (SKT) for optimizing the use of expanded criteria donor kidneys. We did a systematic literature search and meta-analyses when possible, pooling data for calculating relative risks (RR) of major outcomes. Twenty-five studies met the inclusion criteria. One-year serum creatinine was better after DKT vs. SKT (mean difference -0.27 [-0.37, -0.17], P < 0.001), with less incidence of acute rejection (RR 0.66 [0.52, 0.85], P < 0.001) and without differences at five years. Less DGF was seen in DKT (RR 0.88 [0.76, 1.02], P = 0.09). Mortality at 1 and 3 years was similar after dual or SKT, but mortality at five years was lower after DKT (RR 0.71 [0.53, 0.94], P = 0.02). One-year graft loss was similar between dual (n = 4158) and SKT (n = 51 800) (RR 0.97 [0.87, 1.09], P = 0.62). Three- and five-year graft loss was not considered because of high heterogeneity between studies. In conclusion, short-term graft function and long-term patient survival are better in recipients receiving DKT vs. SKT. However, these differences are based on few retrospective reports with a relatively low number of cases. Good quality randomized controlled trials are needed to assess whether the investment of two kidneys in one recipient is justified in face of the current organ shortage. © 2018 Steunstichting ESOT.

Nickel-Cobalt Oxide Decorated Three-Dimensional Graphene as an Enzyme Mimic for Glucose and Calcium Detection.

PubMed

Wu, Meiyan; Meng, Shangjun; Wang, Qian; Si, Weili; Huang, Wei; Dong, Xiaochen

2015-09-30

Glucose and calcium ion play key roles in human bodies. The needlelike NiCo2O4 nanostructures are in situ deposited on three-dimensional graphene foam (3DGF) by a facile hydrothermal procedure. The structure and morphology of the hierarchical NiCo2O4/3DGF are characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. With the self-standing NiCo2O4/3DGF as electrochemical electrode, it can realize the high-sensitivity detections for glucose and calcium ion. The limit of detection can reach 0.38 and 4.45 μM, respectively. In addition, the electrochemical electrode presents excellent selectivity for glucose and calcium ion. This study demonstrates that NiCo2O4/3DGF is a unique and promising material for practical application in both glucose and calcium ion sensing.

Comparative study between kidney transplantation with deceased donor expanded criteria and donor standard criteria in a single center in Brazil.

PubMed

Mota, Luana Soriano; Oliveira, Claudia Maria Costa de; Pinheiro, Francisco Martho Leal; Santos, Larissa Costa de Oliveira; Nóbrega, Danilo Gonçalves; Fernandes, Paula Fbc; Costa, Alda Angélica de Melo; Silva, Sônia Leite da

2016-01-01

Kidney transplants with expanded criteria donor have been associated with improved patient survival compared to those who remain on dialysis. To compare renal function and survival of the kidney graft of deceased donor with expanded criteria and standard criteria over a year in a single transplant center. 255 kidney transplant recipients with deceased donor were included in the study between the years 2011 to 2013 and they were separated into two groups according to the type of donor (expanded criteria donor - ECD - and standard criteria donor - SCD). 231 deceased donor transplants (90.6%) were performed with standard criteria donor (SCD) and 24 (9.4%) with expanded criteria donor (ECD). There was no difference in the prevalence of delayed graft function - DGF - (62.9% vs. 70.8%; p = 0.44). Expanded criteria donor group had lower glomerular filtration rate (GFR) at the end of the 1st year (56.8 ± 26.9 vs. 76.9 ± 23.7; p = 0.001). Patient survival was significantly lower in the ECD group, but the graft survival was not different after death-censored analysis. The ECD group was associated with significantly lower levels of GFR during the first year of transplant and a lower patient survival at the 1st year when compared to the SCD. A aceitação dos rins com critério expandido de doação tem sido associada com melhor sobrevida do paciente em comparação àqueles que permanecem em terapia dialítica. Comparar a função renal e a sobrevida do enxerto renal de doador falecido critério expandido com os de doador falecido critério padrão ao longo de um ano em um único centro de transplantes. Foram incluídos 255 receptores de transplante renal com doador falecido, realizados entre os anos de 2011 a 2013, sendo divididos em dois grupos segundo o tipo de doador (critério expandido - DCE - ou padrão -DCP). Foram avaliados 231 receptores com doador critério ideal (90,6%) e 24 com doador critério expandido (9,4%). Não houve diferença na prevalência de função retardada do enxerto - DGF - (62,9% no DCP vs. 70,8% no DCE; p = 0,44) nos dois grupos. Os transplantes com DCE apresentaram uma taxa de filtração glomerular (TFG) significativamente inferior aos 12 meses (56,8 ± 26,9 vs. 76,9 ± 23,7; p = 0,001). A sobrevida dos pacientes em 1 ano foi significativamente inferior no grupo de DCE, mas não houve diferença na sobrevida dos enxertos após exclusão de perdas por óbito com rim funcionante. O grupo com DCE associou-se com níveis significativamente mais baixos de TFG ao longo do primeiro ano de transplante, bem como uma menor sobrevida dos pacientes em 1 ano, quando comparado ao grupo com doador padrão.

Computerized tongue image segmentation via the double geo-vector flow

PubMed Central

2014-01-01

Background Visual inspection for tongue analysis is a diagnostic method in traditional Chinese medicine (TCM). Owing to the variations in tongue features, such as color, texture, coating, and shape, it is difficult to precisely extract the tongue region in images. This study aims to quantitatively evaluate tongue diagnosis via automatic tongue segmentation. Methods Experiments were conducted using a clinical image dataset provided by the Laboratory of Traditional Medical Syndromes, Shanghai University of TCM. First, a clinical tongue image was refined by a saliency window. Second, we initialized the tongue area as the upper binary part and lower level set matrix. Third, a double geo-vector flow (DGF) was proposed to detect the tongue edge and segment the tongue region in the image, such that the geodesic flow was evaluated in the lower part, and the geo-gradient vector flow was evaluated in the upper part. Results The performance of the DGF was evaluated using 100 images. The DGF exhibited better results compared with other representative studies, with its true-positive volume fraction reaching 98.5%, its false-positive volume fraction being 1.51%, and its false-negative volume fraction being 1.42%. The errors between the proposed automatic segmentation results and manual contours were 0.29 and 1.43% in terms of the standard boundary error metrics of Hausdorff distance and mean distance, respectively. Conclusions By analyzing the time complexity of the DGF and evaluating its performance via standard boundary and area error metrics, we have shown both efficiency and effectiveness of the DGF for automatic tongue image segmentation. PMID:24507094

Computerized tongue image segmentation via the double geo-vector flow.

PubMed

Shi, Miao-Jing; Li, Guo-Zheng; Li, Fu-Feng; Xu, Chao

2014-02-08

Visual inspection for tongue analysis is a diagnostic method in traditional Chinese medicine (TCM). Owing to the variations in tongue features, such as color, texture, coating, and shape, it is difficult to precisely extract the tongue region in images. This study aims to quantitatively evaluate tongue diagnosis via automatic tongue segmentation. Experiments were conducted using a clinical image dataset provided by the Laboratory of Traditional Medical Syndromes, Shanghai University of TCM. First, a clinical tongue image was refined by a saliency window. Second, we initialized the tongue area as the upper binary part and lower level set matrix. Third, a double geo-vector flow (DGF) was proposed to detect the tongue edge and segment the tongue region in the image, such that the geodesic flow was evaluated in the lower part, and the geo-gradient vector flow was evaluated in the upper part. The performance of the DGF was evaluated using 100 images. The DGF exhibited better results compared with other representative studies, with its true-positive volume fraction reaching 98.5%, its false-positive volume fraction being 1.51%, and its false-negative volume fraction being 1.42%. The errors between the proposed automatic segmentation results and manual contours were 0.29 and 1.43% in terms of the standard boundary error metrics of Hausdorff distance and mean distance, respectively. By analyzing the time complexity of the DGF and evaluating its performance via standard boundary and area error metrics, we have shown both efficiency and effectiveness of the DGF for automatic tongue image segmentation.

Mineral-Templated 3D Graphene Architectures for Energy-Efficient Electrodes.

PubMed

Zhang, Mingchao; Chen, Ke; Wang, Chunya; Jian, Muqiang; Yin, Zhe; Liu, Zhenglian; Hong, Guo; Liu, Zhongfan; Zhang, Yingying

2018-05-01

3D graphene networks have shown extraordinary promise for high-performance electrochemical devices. Herein, the chemical vapor deposition synthesis of a highly porous 3D graphene foam (3D-GF) using naturally abundant calcined Iceland crystal as the template is reported. Intriguingly, the Iceland crystal transforms to CaO monolith with evenly distributed micro/meso/macropores through the releasing of CO 2 at high temperature. Meanwhile, the hierarchical structure of the calcined template could be easily tuned under different calcination conditions. By precisely inheriting fine structure from the templates, the as-prepared 3D-GF possesses a tunable hierarchical porosity and low density. Thus, the hierarchical pores offer space for guest hybridization and provide an efficient pathway for ion/charge transport in typical energy conversion/storage systems. The 3D-GF skeleton electrode hybridized with Ni(OH) 2 /Co(OH) 2 through an optimal electrodeposition condition exhibits a high specific capacitance of 2922.2 F g -1 at a scan rate of 10 mV s -1 , and 2138.4 F g -1 at a discharge current density of 3.1 A g -1 . The hybrid 3D-GF symmetry supercapacitor shows a high energy density of 83.0 Wh kg -1 at a power density of 1011.3 W kg -1 and 31.4 Wh kg -1 at a high power density of 18 845.2 W kg -1 . The facile fabrication process enables the mass production of hierarchical porous 3D-GF for high-performance supercapacitors. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

De novo use of a generic formulation of tacrolimus versus reference tacrolimus in kidney transplantation: evaluation of the clinical results, histology in protocol biopsies, and immunological monitoring.

PubMed

Melilli, Edoardo; Crespo, Elena; Sandoval, Diego; Manonelles, Anna; Sala, Neus; Mast, Richard; Padulles, Ariadna; Grinyo, Josep M; Bestard, Oriol; Cruzado, Josep Maria

2015-11-01

The use of generic formulations of immunosuppressive drugs in renal transplantation has been and still is a controversial subject. The lack of clinical studies about safety and efficacy in transplant patients is one of the factors restricting the diffusion of generic drugs in the renal transplant field. Since March 2013, our transplant unit has incorporated generic tacrolimus (Adoport(®) ; Sandoz), replacing the one we were currently using (Prograf(®) ; Astellas). When carrying out our retrospective analysis comparing the two different formulations, we evaluated several clinical results: tacrolimus trough concentrations (C0) at 5-7 days; 1, 3, and 6 months post-transplantation; concentration/dose ratio at 6 months; acute rejection incidence; delayed graft function (DGF); renal function (as CKD-EPI); and proteinuria at 6 months in 120 patients (1:1 ratio of Prograf(®) versus Adoport(®) ), noticing no important differences. We also evaluated the results of protocol biopsies at 6 months in a subgroup of patients, thus verifying the safety and efficacy of this particular generic drug versus the reference product on a histological basis as well. No difference in the development of dnDSA (de novo donor-specific antibody) was found between the two groups. © 2015 Steunstichting ESOT.

Assessment of the Dehydration-Greenhouse Feedback Over the Arctic During Winter

NASA Astrophysics Data System (ADS)

Girard, E.; Stefanof, A.; Peltier-Champigny, M.; Munoz-Alpizar, R.; Dueymes, G.; Jean-Pierre, B.

2007-12-01

The effect of pollution-derived sulphuric acid aerosols on the aerosol-cloud-radiation interactions is investigated over the Arctic for February 1990. Observations suggest that acidic aerosols can decrease the heterogeneous nucleation rate of ice crystals and lower the homogeneous freezing temperature of haze droplets. Based on these observations, we hypothesize that the cloud thermodynamic phase is modified in polluted air mass (Arctic haze). Cloud ice number concentration is reduced, thus promoting further ice crystal growth by the Bergeron-Findeisen process. Hence, ice crystals reach larger sizes and low-level ice crystal precipitation from mixed-phase clouds increases. Enhanced dehydration of the lower troposphere contributes to decrease the water vapour greenhouse effect and cool the surface. A positive feedback is created between surface cooling and air dehydration, accelerating the cold air production. This process is referred to as the dehydration-greenhouse feedback (DGF). Simulations performed using an arctic regional climate model for February 1990, February and March 1985 and 1995 are used to assess the potential effect of the DGF on the Arctic climate. Results show that the DGF has an important effect over the Central and Eurasian Arctic, which is the coldest part of the Arctic with a surface cooling ranging between 0 and -3K. Moreover, the lower tropospheric cooling over the Eurasian and Central Arctic strengthens the atmospheric circulation at upper level, thus increasing the aerosol transport from the mid-latitudes and enhancing the DGF. Over warmer areas, the increased aerosol concentration (caused by the DGF) leads to longer cloud lifetime, which contributes to warm these areas. It is also shown that the maximum ice nuclei reduction must be of the order of 100 to get a significant effect.

Kidney Transplant Outcomes in the Super Obese: A National Study From the UNOS Dataset.

PubMed

Kanthawar, Pooja; Mei, Xiaonan; Daily, Michael F; Chandarana, Jyotin; Shah, Malay; Berger, Jonathan; Castellanos, Ana Lia; Marti, Francesc; Gedaly, Roberto

2016-11-01

We evaluated outcomes of super-obese patients (BMI > 50) undergoing kidney transplantation in the US. We performed a review of 190 super-obese patients undergoing kidney transplantation from 1988 through 2013 using the UNOS dataset. Super-obese patients had a mean age of 45.7 years (21-75 years) and 111 (58.4 %) were female. The mean BMI of the super-obese group was 56 (range 50.0-74.2). A subgroup analysis demonstrated that patients with BMI > 50 had worse survival compared to any other BMI class. The 30-day perioperative mortality and length of stay was 3.7 % and 10.09 days compared to 0.8 % and 7.34 days in nonsuper-obese group. On multivariable analysis, BMI > 50 was an independent predictor of 30-day mortality, with a 4.6-fold increased risk of perioperative death. BMI > 50 increased the risk of delayed graft function and the length of stay by twofold. The multivariable analysis of survival showed a 78 % increased risk of death in this group. Overall patient survival for super-obese transplant recipients at 1, 3, and 5 years was 88, 82, and 76 %, compared to 96, 91, 86 % on patients transplanted with BMI < 50. A propensity score adjusted analysis further demonstrates significant worse survival rates in super-obese patients undergoing kidney transplantation. Super-obese patients had prolonged LOS and worse DGF rates. Perioperative mortality was increased 4.6-fold compared to patients with BMI < 50. In a subgroup analysis, super-obese patients who underwent kidney transplantation had significantly worse graft and patient survival compared to underweight, normal weight, and obesity class I, II, and III (BMI 40-50) patients.

A randomized, prospective study of laparoendoscopic single-site plus one-port versus mini laparoscopic technique for live donor nephrectomy.

PubMed

Lee, Kyu Won; Choi, Sae Woong; Park, Yong Hyun; Bae, Woong Jin; Choi, Yong Sun; Ha, U-Syn; Hong, Sung-Hoo; Lee, Ji Youl; Kim, Sae Woong; Cho, Hyuk Jin

2018-04-01

To compare the clinical outcomes of laparoendoscopic single-site plus one-port donor nephrectomy (LESSOP-DN) and mini laparoscopic donor nephrectomy (MLDN). A prospective randomized controlled trial was conducted from December 2014 to February 2016 in donors scheduled for left donor nephrectomy. Donor and recipient demographics and clinical outcomes including pain scores and questionnaires (BIQ: body image questionnaire, SF-36, patient-reported overall convalescence) were also compared. A total of 121 eligible donors were recruited, of which 99 donors who were scheduled to undergo an operation on their left side were randomized into LESSOP-DN (n = 50) and MLDN (n = 49) groups. There were no significant demographic differences between the two groups. The renal extraction time in the LESS-DN group was shorter than that in the MLDN group (75.89 ± 13.01 vs. 87.31 ± 11.38 min, p < 0.001). Other perioperative parameters and complication rates were comparable between the two groups. The LESSOP-DN group had a smaller incision length than the MLDN group (4.89 ± 0.68 vs. 6.21 ± 1.11 cm, p < 0.001), but cosmetic scores and body image scores were similar in the two groups (p = 0.905, 0.217). Donor quality of life (SF-36) and recovery and satisfaction data were comparable between the two groups. Delayed graft function (DGF) occurred in one recipient undergoing MLDN procedure (2.1%) and progressed to graft failure. There were no differences in cosmetic satisfaction between groups despite the smaller incision size of LESSOP-DN. Safety parameters and subjective measures of postoperative morbidity were similar between the two groups.

German Society for Immunology and Australasian Society for Immunology joint Workshop 3(rd) -4(th) December 2015 - Meeting report.

PubMed

Kurts, Christian; Gottschalk, Catherine; Bedoui, Sammy; Heinzel, Susanne; Godfrey, Dale; Enders, Anselm

2016-02-01

The German Society for Immunology (DGfI) and the Australasian Society for Immunology (ASI) hosted the first DGfI-ASI joint workshop from December 3-4, 2015 in Canberra, Australia. A delegation of 15 distinguished German immunologists discussed the workshop topic "immune regulation in infections and immune mediated diseases" with the aim to establish new German-Australasian collaborations, discuss new concepts in the field of immune regulation and build a scientific network to create more utilizable resources for excellent (trans-border) immunological research. The workshop was associated with the 45(th) Annual Scientific Meeting of the ASI held from Nov 29-Dec 3, 2015, opening up even more opportunities for finding new collaboration partners. A return meeting will be linked to the annual DGfI meeting that will take place in 2017 in Erlangen. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct Determination of MCPD Fatty Acid Esters and Glycidyl Fatty Acid Esters in Vegetable Oils by LC–TOFMS

PubMed Central

Haines, Troy D.; Adlaf, Kevin J.; Pierceall, Robert M.; Lee, Inmok; Venkitasubramanian, Padmesh

2010-01-01

Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable oils. The results of the LC–TOFMS method were compared with the DGF method. The DGF method consistently gave results that were greater than the LC–TOFMS method. The levels of MCPD esters and glycidyl esters found in a variety of vegetable oils are reported. MCPD monoesters were not found in any oil samples. MCPD diesters were found only in samples containing palm oil, and were not present in all palm oil samples. Glycidyl esters were found in a wide variety of oils. Some processing conditions that influence the concentration of MCPD esters and glycidyl esters are discussed. PMID:21350591

Green’s Functions for an Anisotropic Medium: Part 1. Unbounded Case

DTIC Science & Technology

1993-12-01

AA 2 - x • , - a or b (41a) td A -2 A-- ’ -L x " " - , -a or b (41b) 13 4. DISCUSSION Having now derived the DGF of the unbounded biaxially...B 2 A3 121/3 b s- - + (_ + )A + [ (_ L_1/ + - (A13) A - 1 (3q - b) (Al4a) (3q B - -L (-2b 3 + 9bq + 27r) (Al4b) q - Ac - 4d (Al5a) r - - Ad 2 + 4bd - C

Analysis and Modeling of Shear Waves Generated by Explosions at the San Andreas Fault Observatory at Depth

DTIC Science & Technology

2011-09-01

No. BAA09-69 ABSTRACT Using multiple deployments of an 80-element, three-component borehole seismic array stretching from the surface to 2.3 km...NNSA). 14. ABSTRACT Using multiple deployments of an 80-element, three-component borehole seismic array stretching from the surface to 2.3 km depth...generated using the direct Green’s function (DGF) method of Friederich and Dalkolmo (1995). This method synthesizes the seismic wavefield for a spherically

Divergence with gene flow within the recent chipmunk radiation (Tamias)

PubMed Central

Sullivan, J; Demboski, J R; Bell, K C; Hird, S; Sarver, B; Reid, N; Good, J M

2014-01-01

Increasing data have supported the importance of divergence with gene flow (DGF) in the generation of biological diversity. In such cases, lineage divergence occurs on a shorter timescale than does the completion of reproductive isolation. Although it is critical to explore the mechanisms driving divergence and preventing homogenization by hybridization, it is equally important to document cases of DGF in nature. Here we synthesize data that have accumulated over the last dozen or so years on DGF in the chipmunk (Tamias) radiation with new data that quantify very high rates of mitochondrial DNA (mtDNA) introgression among para- and sympatric species in the T. quadrivittatus group in the central and southern Rocky Mountains. These new data (188 cytochrome b sequences) bring the total number of sequences up to 1871; roughly 16% (298) of the chipmunks we have sequenced exhibit introgressed mtDNA. This includes ongoing introgression between subspecies and between both closely related and distantly related taxa. In addition, we have identified several taxa that are apparently fixed for ancient introgressions and in which there is no evidence of ongoing introgression. A recurrent observation is that these introgressions occur between ecologically and morphologically diverged, sometimes non-sister taxa that engage in well-documented niche partitioning. Thus, the chipmunk radiation in western North America represents an excellent mammalian example of speciation in the face of recurrent gene flow among lineages and where biogeography, habitat differentiation and mating systems suggest important roles for both ecological and sexual selection. PMID:24781803

The Dense Gas Fraction in the Central Molecular Zone in the Milky Way

NASA Astrophysics Data System (ADS)

Vargas-Salazar, Irene; Battersby, Cara; Walker, Daniel; Zhang, Qizhou; CMZoom

2017-01-01

The Central Molecular Zone (CMZ), a large reservoir of dense molecular gas occupying the central 500pc of the Milky Way, is an extreme star-formation environment where the validity of star formation prescriptions can be tested. The star formation rate (SFR) in the CMZ is about an order of magnitude lower than predicted by the currently accepted prescriptions. An international team lead by PIs Battersby and Keto conducted a survey from 2013-2016 called CMZoom using the Submillimeter Array (SMA) to characterize star formation within resolved molecular clouds in this extreme region. One of the main goals of this survey is to further quantify and understand the low SFR found in this region of the Galaxy. Here, we use the CASA software package to run synthetic observations of hydrodynamical simulations of molecular clouds and vary the observation parameters in such a way that we explore the real parameter space that was probed during the survey. The purpose of this is to investigate how the different observational parameters affect the resultant data. Afterwards, we estimate the “dense gas fraction” (DGF) found in regions across the CMZ. This estimate was found by using the interferometric flux from SMA and the single-dish flux from the Bolocam Galactic Plane Survey. We analyzed the effects that different locations of the CMZ had on these approximate DGF. With these simulations and DGF estimates, we are able to generate improved methods to analyze the data from this survey that will help understand star formation in an extreme environment.The SAO REU program is funded in part by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no.1262851, and by the Smithsonian Institution.

Excellent Aesthetic and Functional Outcome After Fractionated Carbon Dioxide Laser Skin Graft Revision Surgery: Case Report and Review of Laser Skin Graft Revision Techniques.

PubMed

Ho, Derek; Jagdeo, Jared

2015-11-01

Skin grafts are utilized in dermatology to reconstruct a defect secondary to surgery or trauma of the skin. Common indications for skin grafts include surgical removal of cutaneous malignancies, replacement of tissue after burns or lacerations, and hair transplantation in alopecia. Skin grafts may be cosmetically displeasing, functionally limiting, and significantly impact patient's quality-of-life. There is limited published data regarding skin graft revision to enhance aesthetics and function. Here, we present a case demonstrating excellent aesthetic and functional outcome after fractionated carbon dioxide (CO2) laser skin graft revision surgery and review of the medical literature on laser skin graft revision techniques.

Comparison of endothelial function of coronary artery bypass grafts in diabetic and nondiabetic patients: Which graft offers the best?

PubMed Central

Gür, Demet Özkaramanlı; Gür, Özcan; Gürkan, Selami; Cömez, Selcem; Gönültaş, Aylin; Yılmaz, Murat

2016-01-01

Objective: Diabetes associated endothelial dysfunction, which determines both long and short term graft patency, is not uniform in all coronary artery bypass surgery (CABG) grafts. Herein this study, we aimed to investigate the degree of endothelial dysfunction in diabetic radial artery (RA), internal mammarian artery (IMA) and saphenous vein (SV) grafts in vitro tissue bath system. Methods: This is a prospective experimental study. Fifteen diabetic and 15 non-diabetic patients were included to the study. A total number of 96 graft samples were collected; 16 graft samples for each graft type from both diabetic and non-diabetic patients. Arterial grafts were harvested with pedicles and SV grafts were harvested by ‘no touch’ technique. Vasodilatation response of vascular rings to carbachol, which induces nitric oxide (NO) mediated vasodilatation, was designated as the measure of endothelial function. Results: The IMA grafts had the most prominent NO mediated vasodilatation in both diabetic and non-diabetic patients, concluding a better preserved endothelial function than SV and RA. The ‘no-touch’ SV and RA grafts had similar vasodilatation responses in non-diabetic patients. In diabetic patients, on the other hand, RA grafts exhibited the least vasodilatation response (ie. worst endothelial function), even less vasodilatation than ‘no touch’ SV grafts (p<0.0001). Conclusion: Deteriorated function of RA grafts in diabetic patients, even worse than SV grafts made evident by this study, encourages the use of ‘no touch’ technique as the method of SV harvesting and more meticulous imaging of RA before its use as a graft in diabetic patients. PMID:26301347

Functional characterization of optimized acellular peripheral nerve graft in a rat sciatic nerve injury model.

PubMed

Nagao, Ryan J; Lundy, Scott; Khaing, Zin Z; Schmidt, Christine E

2011-07-01

Acellular grafts are a viable option for use in nerve reconstruction surgeries. Recently, our lab created a novel optimized decellularization procedure that removes immunological material while leaving the majority of the extracellular matrix structure intact. The optimized acellular (OA) graft has been shown to elicit an immune response equal to or less than that elicited by the isograft, the analog of the autograft in the rat model. We investigated the performance of the OA graft to provide functional recovery in a long-term study. We performed a long-term functional regeneration evaluation study using the sciatic functional index to quantify recovery of Lewis rats at regular time intervals for up to 52 weeks after graft implantation following 1 cm sciatic nerve resection. OA grafts were compared against other decellularized methods (Sondell treatment and thermal decellularization), as well as the isograft and primary neurorrhaphy. The OA graft supported comparable functional recovery to the isograft and superior regeneration to thermal and Sondell decellularization methods. Furthermore, the OA graft promoted early recovery to a greater degree compared to acellular grafts obtained using either the thermal or the Sondell methods. Equivalent functional recovery to the isograft suggests that the OA nerve graft may be a future clinical alternative to the current autologous tissue graft.

[Urology and National Socialism illustrated by the example of Leopold Casper (1859-1959)].

PubMed

Moll, F H; Rathert, P; Fangerau, H

2009-09-01

Leopold Casper (1859-1959) was one of the founders of the German Urological Society (DGfU) in 1906. He introduced functional kidney testing and a special cystoscope for ureteral catheterization. In 1913 he was president of the 4th congress held in the German capital Berlin. His textbook on genito-urinary diseases was translated by Charles W. Bonney in 1910 and proved the high quality of his scientific work. As a Jew he was forced to leave Nazi Germany later on in 1933 and from 1941 onwards he lived in New York. The anniversary of his 150th birthday should be remembered with special focus on the exodus of Jewish German scientists during the Nazi period.

Professional Training Programs of Masters in Adult Education at Universities of Germany

ERIC Educational Resources Information Center

Hizhynska, Tetiana

2015-01-01

The German experience in professional training of teaching staff in adult education has been analyzed; it has been clarified that modern educational programs of Bachelor and Master specialties are based on the basic educational program offered by Adult Education Sectional Commission of Pedagogical Sciences in Germany (DGfE); value-targeted and…

Personal experience with the procurement of 132 liver allografts

PubMed Central

Yanaga, K.; Tzakis, A.G.; Starzl, T.E.

2010-01-01

A single donor surgeon's experience procuring the livers from 132 donors is described. Thirty-seven grafts (28.9%) had hepatic arterial anomalies, 19 (14.4%) of which required arterial reconstruction prior to transplantation. Of the 121 grafts evaluated for early function, 103 grafts (85.2%) functioned well, whereas 14 grafts (11.6%) functioned poorly and 4 grafts (3.3%) failed to function at all. The variables associated with less than optimal function of the graft consisted of donor age (P < 0.05), duration of donor's stay in the intensive care unit (P < 0.005), abnormal graft appearance (P < 0.05), and such recipient problems as vascular thromboses during or immediately following transplantation (P < 0.005). A new preservation fluid, University of Wisconsin solution, allowed safe and longer cold storage of the liver allograft than did Euro-Collins' solution (P < 0.0001). A parameter of liver allograft viability, which is simple and predictive of allograft function prior to the actual transplant procedure, is urgently needed. PMID:2803485

Intrastriatal Grafting of Chromospheres: Survival and Functional Effects in the 6-OHDA Rat Model of Parkinson's Disease

PubMed Central

Boronat-García, Alejandra; Palomero-Rivero, Marcela; Guerra-Crespo, Magdalena; Millán-Aldaco, Diana; Drucker-Colín, René

2016-01-01

Cell replacement therapy in Parkinson’s disease (PD) aims at re-establishing dopamine neurotransmission in the striatum by grafting dopamine-releasing cells. Chromaffin cell (CC) grafts produce some transitory improvements of functional motor deficits in PD animal models, and have the advantage of allowing autologous transplantation. However, CC grafts have exhibited low survival, poor functional effects and dopamine release compared to other cell types. Recently, chromaffin progenitor-like cells were isolated from bovine and human adult adrenal medulla. Under low-attachment conditions, these cells aggregate and grow as spheres, named chromospheres. Here, we found that bovine-derived chromosphere-cell cultures exhibit a greater fraction of cells with a dopaminergic phenotype and higher dopamine release than CC. Chromospheres grafted in a rat model of PD survived in 57% of the total grafted animals. Behavioral tests showed that surviving chromosphere cells induce a reduction in motor alterations for at least 3 months after grafting. Finally, we found that compared with CC, chromosphere grafts survive more and produce more robust and consistent motor improvements. However, further experiments would be necessary to determine whether the functional benefits induced by chromosphere grafts can be improved, and also to elucidate the mechanisms underlying the functional effects of the grafts. PMID:27525967

Improvement of liver injury and survival by JNK2 and iNOS deficiency in liver transplants from cardiac death mice.

PubMed

Liu, Qinlong; Rehman, Hasibur; Krishnasamy, Yasodha; Schnellmann, Rick G; Lemasters, John J; Zhong, Zhi

2015-07-01

Inclusion of liver grafts from cardiac death donors (CDD) would increase the availability of donor livers but is hampered by a higher risk of primary non-function. Here, we seek to determine mechanisms that contribute to primary non-function of liver grafts from CDD with the goal to develop strategies for improved function and outcome, focusing on c-Jun-N-terminal kinase (JNK) activation and mitochondrial depolarization, two known mediators of graft failure. Livers explanted from wild-type, inducible nitric oxide synthase knockout (iNOS(-/-)), JNK1(-/-) or JNK2(-/-) mice after 45-min aorta clamping were implanted into wild-type recipients. Mitochondrial depolarization was detected by intravital confocal microscopy in living recipients. After transplantation of wild-type CDD livers, graft iNOS expression and 3-nitrotyrosine adducts increased, but hepatic endothelial NOS expression was unchanged. Graft injury and dysfunction were substantially higher in CDD grafts than in non-CDD grafts. iNOS deficiency and inhibition attenuated injury and improved function and survival of CDD grafts. JNK1/2 and apoptosis signal-regulating kinase-1 activation increased markedly in wild-type CDD grafts, which was blunted by iNOS deficiency. JNK inhibition and JNK2 deficiency, but not JNK1 deficiency, decreased injury and improved function and survival of CDD grafts. Mitochondrial depolarization and binding of phospho-JNK2 to Sab, a mitochondrial protein linked to the mitochondrial permeability transition, were higher in CDD than in non-CDD grafts. iNOS deficiency, JNK inhibition and JNK2 deficiency all decreased mitochondrial depolarization and blunted ATP depletion in CDD grafts. JNK inhibition and deficiency did not decrease 3-nitrotyrosine adducts in CDD grafts. The iNOS-JNK2-Sab pathway promotes CDD graft failure via increased mitochondrial depolarization, and is an attractive target to improve liver function and survival in CDD liver transplantation recipients. Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Restoration of Failed Renal Graft Function After Successful Angioplasty of Pressure-Resistant Renal Artery Stenosis Using a Cutting Balloon: A Case Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peregrin, J. H., E-mail: jape@medicon.c; Buergelova, M.

2009-05-15

This study is the report of a 37-year-old male with a transplanted kidney from a 3.5-year-old donor: the graft had two arteries transplanted with an aortic patch to an external iliac artery. Four months after transplantation, the graft function deteriorated, together with the development of hypertension. Stenosis of both graft arteries was detected and the patient was referred for angioplasty. The angiographic result was suboptimal, nevertheless, the graft function improved and was more or less stable (serum creatinine, 160-200 {mu}mol/l) for 4 years, along with persistently difficult-to-control hypertension. Five years after transplantation, the graft function deteriorated again and severe graftmore » artery restenosis was detected. The restenosis did not respond to dilatation, graft function failed, hypertension decompensated, and left ventricular failure developed. The patient required dialysis. A cutting balloon angioplasty opened the artery, and kidney function was restored after a few days: the serum creatinine level dropped to 140-160 {mu}mol/l, and the glomerular filtration rate (creatinine clearance) to 0.65 ml/min/1.73 m{sup 2}. The graft function has now been stable for more than 2 years, however, the hypertension is still difficult to control.« less

Delayed Graft Function in Living-Donor Kidney Transplant: A Middle Eastern Perspective.

PubMed

Al Otaibi, Torki; Ahmadpoor, Pedram; Allawi, Ali Abdulmajid Dyab; Habhab, Wael Taher; Khatami, Mohammad Reza; Nafar, Mohsen; Glotz, Denis

2016-02-01

With an increased incidence of living-donor kidney transplants, in response to increasing unmet needs for renal transplant, a clear understanding of determinants of posttransplant outcomes is essential. The importance of delayed graft function in deceased-donor kidney transplant is now part of conventional medical wisdom, due to the large amount of evidence focused on this aspect. However, the same is not true for living-donor kidney transplant, partly due to lack of evidence on this crucial clinical question and partly due to lack of awareness about this issue. The current review aims to highlight the importance of delayed graft function as a crucial determinant of outcomes in living-donor kidney transplant. An exhaustive search of online medical databases was performed with appropriate search criteria to collect evidence about delayed graft function after living-donor kidney transplant, with a special focus on studies from the Middle East. Data on incidence, impact, risk factors, and possible prevention modalities of delayed graft function in patients undergoing living-donor kidney transplant are presented. A key finding of this review is that contemporary incidence rates reported from the Middle East are comparatively higher than those reported from outside the region. Although in absolute terms the incidence is lower than deceased donor kidney transplant, the effects of delayed graft function on graft rejection and graft and patient survival are sufficiently large to warrant the formulation of specific treatment protocols. Key to formulating prevention and treatment strategies is identifying discrete risk factors for delayed graft function. Although this evidence is scant, an overview has been provided. Further studies examining different aspects of delayed graft function incidence after living-donor kidney transplant are urgently needed to address a so far little known clinical question.

Factors that Affected Functional Outcome After a Delayed Excision and Split-Thickness Skin Graft on the Dorsal Side of Burned Hands.

PubMed

Shichinohe, Ryuji; Yamamoto, Yuhei; Kawashima, Kunihiro; Kimura, Chu; Ono, Kentaro; Horiuchi, Katsumi; Yoshida, Tetsunori; Murao, Naoki; Hayashi, Toshihiko; Funayama, Emi; Oyama, Akihiko; Furukawa, Hiroshi

Early excision and skin grafting is the principle treatment for a burned hand although there are occasions when it cannot be done such as severe general condition, delayed consultation, and the lack of a definitive assessment of burn depth. This study analyzes the factors that affected function after a delayed excision and skin graft for hands with a deep dermal burn. This study retrospectively evaluated 43 burned hands that required a delayed excision and split-thickness skin graft on the dorsal side. Cases were required to only have split-thickness skin grafting from the dorsum of the hand and fingers distally to at least the proximal interphalangeal joint at least 8 days after the injury. The hands were divided into two functional categories: Functional category A, normal or nearly normal joint movements, and functional category B, abnormal joint movements. Demographic data were assessed statistically by a univariate analysis following a multiple regression analysis by a stepwise selection. A significant difference was observed between the groups in the number of days from grafting to complete wound healing of the graft site and with or without an escharotomy in the analysis. These parameters were statistically significant predictors of functional category B. The functional outcome of a burned hand after a delayed excision and split-thickness skin graft on the dorsal side became degraded depending on the number of days from grafting to complete wound healing. Cases that underwent an escharotomy also showed deterioration in function.

[Is there an age limit for cadaveric kidney donors currently?].

PubMed

Cofán Pujol, F; Oppenheimer Salinas, F; Talbot-Wright, R; Carretero González, P

1996-12-01

The insufficient number of kidney transplants has gradually raised the age limit to the cadaver kidney donor. The use of grafts harvested from older donors has been debated due to the existing structural and functional changes that might influence renal function and long-term graft survival. The foregoing aspects are discussed herein. The anatomical, histological and functional changes in the kidney associated with ageing are analyzed. The clinical experience with renal grafts from older donors before and after cyclosporine became available are reviewed. The ethical issues on whether grafts from very old donors should be used and who should receive these grafts are discussed. The use of grafts from donors over 60 years old had no significant short and medium term differences in comparison with younger donors in terms of graft survival, although a higher incidence of acute tubular necrosis and poor renal function have been observed. There are no conclusive studies on the long-term effects on graft survival when kidneys from donors aged over 65 are utilized. In our experience, the results achieved with grafts from donors over 70 has been unsatisfactory. The guidelines utilized in the selection of grafts derived from older donors are presented. Grafts from donors aged 60 to 70 may be utilized in renal transplantation following precise selection criteria. Graft survival has been satisfactory, although a higher incidence of acute tubular necrosis and higher creatinine levels have been observed. We do not advocate the use of grafts from donors over 70, except in very exceptional cases. Long-term multicenter studies on grafts from very old donors and trials using alternative immunosuppressor modalities that might permit optimal use of these grafts are warranted.

Urinary Liver Type Fatty Acid Binding Protein Is Negatively Associated With Estimated Glomerular Filtration Rate in Renal Transplant Recipients With Graft Loss.

PubMed

Huang, Y-C; Chang, Y-S; Chen, C-C; Tsai, S-F; Yu, T-M; Wu, M-J; Chen, C-H

2018-05-01

Liver type fatty acid binding protein (L-FABP) is abundant not only in the liver but also in the kidney and is excreted in urine. Its primary function is to facilitate intracellular long chain fatty acid transport and it might also act as an endogenous antioxidant molecular. The purpose of this study was to investigate whether plasma or urinary L-FABP levels were associated with graft function in renal transplant recipients. Sixty-seven renal transplant recipients with a mean age of 48.8 years were recruited. The mean duration of renal transplantation was 4131 days. Recipients were divided into 2 groups based on their estimated glomerular filtration rate (eGFR) values: moderate graft function (eGFR ≥60 mL/min/1.73 m 2 ) and low graft function (eGFR <60 mL/min/1.73 m 2 ). Fasting plasma and urinary L-FABP levels were measured. There was no significant difference in plasma L-FABP level between the 2 groups, although recipients in the low graft function group had significantly lower urinary L-FABP level when compared with recipients in the moderate graft function group. Plasma and urinary L-FABP levels were not associated with eGFR in the 67 recipients; however, urinary L-FABP level (β = -1.24, P = .037) and level adjusted by urinary creatinine (β = -0.75, P = .046) were significantly negatively associated with eGFR in recipients with low graft function after adjusting for potential confounders. Increased urinary L-FABP level seems to be a significant indicator of decreased graft function in renal transplant recipients with loss of graft function. Copyright © 2018 Elsevier Inc. All rights reserved.

Production of functional sperm by subcutaneous auto-grafting of immature testes in rainbow trout.

PubMed

Hayashi, Makoto; Sakuma, Daika; Yoshizaki, Goro

2018-02-01

Sexually mature individuals are indispensable for breeding programs. Salmonids require a long period before reaching sexual maturity, so we aimed to shorten the period required to obtain functional sperm by grafting immature testicular fragments into mature recipients, which we predicted would allow the grafted testicular fragments to skip the long pre-pubertal period. First, we demonstrated successful subcutaneous auto-grafting of testicular fragments in rainbow trout. Unilateral testectomy was performed, and the isolated immature testicular fragment was auto-grafted into the subcutaneous space along the back of recipient fish. The grafted testicular fragments developed synchronously with the recipients' testis remaining in its body cavity, and both eventually produced functional sperm. Next, immature testicular fragments were auto-grafted into the subcutaneous space of sexually mature males. We achieved this, without immune rejection, by isolating and cryopreserving testes from immature fish, and rearing these unilaterally testectomized fish until sexual maturity. The cryopreserved testes were then auto-grafted into the original, now spermiating fish. The grated immature testicular fragments differentiated and produced functional sperm within 5 months after grafting. By combining this grafting method with a technique to avoid immune rejection, we expect to develop a practical method for producing sperm in a shorter period in salmonids. © 2017 Wiley Periodicals, Inc.

Implantation of Right Kidneys: Is the Risk of Technical Graft Loss Real?

PubMed

Khan, Taqi T; Ahmad, Nadeem; Siddique, Kashif; Fourtounas, Konstantinos

2018-05-01

The left kidney (LK) is preferred by transplant surgeons, because its vein is always of good length and has a thick wall that enables safe suturing. On the other hand, the right renal vein is generally shorter and thinner walled, and well known for its technical difficulty during venous anastomosis, and can result in graft loss. We examined our living (LD) and deceased donor (DD) recipient data and compared the incidence of technical graft loss and early graft function in right and left kidneys. A cohort of 58 adult and pediatric recipients received an LD or DD kidney between January 2015 and December 2016. The donor and recipient data were retrieved and retrospectively analyzed. Technical graft loss was defined as graft thrombosis within the 7 days after transplant. Right kidneys (RKs) were not a risk factor for technical graft loss, and no graft was lost for technical reasons in either LD or DD transplants. Early graft function in LK and RKs was also comparable in the LD cohort, and there were no LKs in the DD cohort. Based on our data, the use of RKs was not a risk factor for technical graft loss and early graft function was comparable to LKs.

Identification and characterization of kidney transplants with good glomerular filtration rate at 1 year but subsequent progressive loss of renal function.

PubMed

Park, Walter D; Larson, Timothy S; Griffin, Matthew D; Stegall, Mark D

2012-11-15

After the first year after kidney transplantation, 3% to 5% of grafts fail each year but detailed studies of how grafts progress to failure are lacking. This study aimed to analyze the functional stability of kidney transplants between 1 and 5 years after transplantation and to identify initially well-functioning grafts with progressive decline in allograft function. The study included 788 adult conventional kidney transplants performed at the Mayo Clinic Rochester between January 2000 and December 2005 with a minimum graft survival and follow-up of 2.6 years. The modification of diet in renal disease equation for estimating glomerular filtration rate (eGFR(MDRD)) was used to calculate the slope of renal function over time using all available serum creatinine values between 1 and 5 years after transplantation. Most transplants demonstrated good function (eGFR(MDRD) ≥40 mL/min) at 1 year with positive eGFR(MDRD) slope between 1 and 5 years after transplantation. However, a subset of grafts with 1-year eGFR(MDRD) ≥40 mL/min exhibited strongly negative eGFR(MDRD) slope between 1 and 5 years suggestive of progressive loss of graft function. Forty-one percent of this subset reached graft failure during follow-up, accounting for 69% of allograft failures occurring after 2.5 years after transplantation. This pattern of progressive decline in estimated glomerular filtration rate despite good early function was associated with but not fully attributable to factors suggestive of enhanced antidonor immunity. Longitudinal analysis of serial estimated glomerular filtration ratemeasurements identifies initially well-functioning kidney transplants at high risk for subsequent graft loss. For this subset, further studies are needed to identify modifiable causes of functional decline.

Increased primary non-function in transplanted deceased-donor kidneys flushed with histidine-tryptophan-ketoglutarate solution.

PubMed

Stevens, R B; Skorupa, J Y; Rigley, T H; Yannam, G R; Nielsen, K J; Schriner, M E; Skorupa, A J; Murante, A; Holdaway, E; Wrenshall, L E

2009-05-01

Histidine-Tryptophan-Ketoglutarate (HTK) solution is increasingly used to flush and preserve organ donor kidneys, with efficacy claimed equivalent to University of Wisconsin (UW) solution. We observed and reported increased graft pancreatitis in pancreata flushed with HTK solution, which prompted this review of transplanting HTK-flushed kidneys. We analyzed outcomes of deceased-donor kidneys flushed with HTK and UW solutions with a minimum of 12 months follow-up, excluding pediatric and multi-organ recipients. We evaluated patient and graft survival and rejection rates, variables that might constitute hazards to graft survival and renal function. Two-year patient survival, rejection, renal function and graft survival were not different, but early graft loss (<6 months) was worse in HTK-flushed kidneys (p < 0.03). A Cox analysis of donor grade, cold ischemic time, panel reactive antibodies (PRA), donor race, first vs. repeat transplant, rejection and flush solution showed that only HTK use predicted early graft loss (p < 0.04; relative risk = 3.24), almost exclusively attributable to primary non-function (HTK, n = 5 (6.30%); UW, n = 1 (0.65%); p = 0.02). Delayed graft function and early graft loss with HTK occurred only in lesser grade kidneys, suggesting it should be used with caution in marginal donors.

Incorporation of functionalized gold nanoparticles into nanofibers for enhanced attachment and differentiation of mammalian cells

PubMed Central

2012-01-01

Background Electrospun nanofibers have been widely used as substrata for mammalian cell culture owing to their structural similarity to natural extracellular matrices. Structurally consistent electrospun nanofibers can be produced with synthetic polymers but require chemical modification to graft cell-adhesive molecules to make the nanofibers functional. Development of a facile method of grafting functional molecules on the nanofibers will contribute to the production of diverse cell type-specific nanofiber substrata. Results Small molecules, peptides, and functionalized gold nanoparticles were successfully incorporated with polymethylglutarimide (PMGI) nanofibers through electrospinning. The PMGI nanofibers functionalized by the grafted AuNPs, which were labeled with cell-adhesive peptides, enhanced HeLa cell attachment and potentiated cardiomyocyte differentiation of human pluripotent stem cells. Conclusions PMGI nanofibers can be functionalized simply by co-electrospinning with the grafting materials. In addition, grafting functionalized AuNPs enable high-density localization of the cell-adhesive peptides on the nanofiber. The results of the present study suggest that more cell type-specific synthetic substrata can be fabricated with molecule-doped nanofibers, in which diverse functional molecules are grafted alone or in combination with other molecules at different concentrations. PMID:22686683

Functionalization of chitosan by a free radical reaction: Characterization, antioxidant and antibacterial potential.

PubMed

Moreno-Vásquez, María Jesús; Valenzuela-Buitimea, Emma Lucía; Plascencia-Jatomea, Maribel; Encinas-Encinas, José Carmelo; Rodríguez-Félix, Francisco; Sánchez-Valdes, Saúl; Rosas-Burgos, Ema Carina; Ocaño-Higuera, Víctor Manuel; Graciano-Verdugo, Abril Zoraida

2017-01-02

Chitosan was functionalized with epigallocatechin gallate (EGCG) by a free radical-induced grafting procedure, which was carried out by a redox pair (ascorbic acid/hydrogen peroxide) as the radical initiator. The successful preparation of EGCG grafted-chitosan was verified by spectroscopic (UV, FTIR and XPS) and thermal (DSC and TGA) analyses. The degree of grafting of phenolic compounds onto the chitosan was determined by the Folin-Ciocalteu procedure. Additionally, the biological activities (antioxidant and antibacterial) of pure EGCG, blank chitosan and EGCG grafted-chitosan were evaluated. The spectroscopic and thermal results indicate chitosan functionalization with EGCG; the EGCG content was 25.8mg/g of EGCG grafted-chitosan. The antibacterial activity of the EGCG grafted-chitosan was increased compared to pure EGCG or blank chitosan against S. aureus and Pseudomonas sp. (p<0.05). Additionally, EGCG grafted-chitosan showed higher antioxidant activity than blank chitosan. These results indicate that EGCG grafted-chitosan might be useful in active food packaging. Copyright © 2016 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Mingyi; Xu, Xiaoyang, E-mail: xiaoyangxu2012@163.com; Wu, Tao

Highlights: • Graphene oxide (GO) was modified by chemical reactions to functionalized GO (FGO). • The FGOs and the GO were then subjected to in situ free radical polymerization. • Hydroxyl groups of GO were the most reactive grafting sites. - Abstract: Graphene oxide (GO) was modified using chemical reactions to obtain three types of functionalized GO sheets (FGO). The FGO sheets and the GO were then subjected to in situ free radical polymerization in order to study the grafting polymerization. The FGO and grafted-.FGO were analyzed with Fourier transform infrared spectroscopy, scanning electronic microscopy, thermo-gravimetric analysis (TGA) and X-raymore » photoelectron spectroscopy (XPS). The grafting percentages in the materials were calculated using the TGA and XPS results. The FGO sheets with different functional groups exhibited different grafting abilities, and hydroxyl groups were proven to be the most reactive grafting sites for the in situ free radical grafting polymerization of polyacrylamide.« less

Impact of Procedure-Related Complications on Long-term Islet Transplantation Outcome.

PubMed

Caiazzo, Robert; Vantyghem, Marie-Christine; Raverdi, Violeta; Bonner, Caroline; Gmyr, Valery; Defrance, Frederique; Leroy, Clara; Sergent, Geraldine; Hubert, Thomas; Ernst, Oliver; Noel, Christian; Kerr-Conte, Julie; Pattou, François

2015-05-01

Pancreatic islet transplantation offers a promising biotherapy for the treatment of type 1 diabetes, but this procedure has met significant challenges over the years. One such challenge is to address why primary graft function still remains inconsistent after islet transplantation. Several variables have been shown to affect graft function, but the impact of procedure-related complications on primary and long-term graft functions has not yet been explored. Twenty-six patients with established type 1 diabetes were included in this study. Each patient had two to three intraportal islet infusions to obtain 10,000 islet equivalent (IEQ)/kg in body weight, equaling a total of 68 islet infusions. Islet transplantation consisted of three sequential fresh islet infusions within 3 months. Islet infusions were performed surgically or under ultrasound guidance, depending on patient morphology, availability of the radiology suite, and patient medical history. Prospective assessment of adverse events was recorded and graded using "Common Terminology Criteria for adverse events in Trials of Adult Pancreatic Islet Transplantation." There were no deaths or patients dropouts. Early complications occurred in nine of 68 procedures. β score 1 month after the last graft and optimal graft function (β score ≥7) rate were significantly lower in cases of procedure-related complications (P = 0.02, P = 0.03). Procedure-related complications negatively impacted graft function (P = 0.009) and was an independent predictive factor of long-term graft survival (P = 0.033) in multivariate analysis. Complications occurring during radiologic or surgical intraportal islet transplantation significantly impair primary graft function and graft survival regardless of their severity.

Surface functionalization of solid state ultra-high molecular weight polyethylene through chemical grafting

NASA Astrophysics Data System (ADS)

Sherazi, Tauqir A.; Rehman, Tayyiba; Naqvi, Syed Ali Raza; Shaikh, Ahson Jabbar; Shahzad, Sohail Anjum; Abbas, Ghazanfar; Raza, Rizwan; Waseem, Amir

2015-12-01

The surface of ultra-high molecular weight polyethylene (UHMWPE) powder was functionalized with styrene using chemical grafting technique. The grafting process was initiated through radical generation on base polymer matrix in the solid state by sodium thiosulfate, while peroxides formed at radical sites during this process were dissociated by ceric ammonium nitrate. Various factors were optimized and reasonably high level of monomer grafting was achieved, i.e., 15.6%. The effect of different acids as additive and divinyl benzene (DVB) as a cross-linking agent was also studied. Post-grafting sulfonation was conducted to introduce the ionic moieties to the grafted polymer. Ion-exchange capacity (IEC) was measured experimentally and is found to be 1.04 meq g-1, which is in close agreement with the theoretical IEC values. The chemical structure of grafted and functionalized polymer was characterized by attenuated total reflection infrared spectroscopy (ATR-FTIR) and thermal properties were investigated by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal analysis depicts that the presence of radicals on the polymer chain accelerates the thermal decomposition process. The results signify that the chemical grafting is an effective tool for substantial surface modification and subsequent functionalization of polyethylene.

Angiographic predictors of 3-year patency of bypass grafts implanted on the right coronary artery system: a prospective randomized comparison of gastroepiploic artery, saphenous vein, and right internal thoracic artery grafts.

PubMed

Glineur, David; D'hoore, William; de Kerchove, Laurent; Noirhomme, Philippe; Price, Joel; Hanet, Claude; El Khoury, Gebrine

2011-11-01

Saphenous vein, in situ right gastroepiploic artery, and right internal thoracic artery grafts are routinely used to revascularize the right coronary artery. Little is known about the predictive value of objective preoperative angiographic parameters on midterm graft patency. We prospectively enrolled 210 consecutive patients undergoing coronary revascularization. Revascularization of the right coronary artery was randomly performed with the saphenous vein grafts in 81 patients and the right gastroepiploic artery in 92 patients. During the same study period, 37 patients received right coronary artery revascularization with the right internal thoracic artery used in a Y-composite fashion. All patients underwent a protocol-driven coronary angiogram 3 years after surgery. Preoperative angiographic parameters included minimum lumen diameter percent stenosis measured by quantitative angiography. A graft was considered "not functional" with patency scores of 0 to 2 and "functional" with patency scores of 3 or 4. Angiographic follow-up was 100% complete. A significant difference in the distribution of flow patterns was observed in the 3 groups. In multivariate analysis, the use of a saphenous vein graft was associated with superior graft functionality compared with the other conduits (odds ratio, 6.1; 95% confidence interval, 2.4-15). Graft function was negatively influenced by the minimum lumen diameter (odds ratio, 0.11; confidence interval, 0.05-0.25). In the right gastroepiploic artery and right internal thoracic artery groups, the proportion of functional grafts was higher when the minimum lumen diameter was below a threshold value in the third minimum lumen diameter quartile (0.64-1.30 mm). Preoperative angiography predicts graft patency in the right gastroepiploic artery and right internal thoracic artery, whereas the flow pattern in saphenous vein grafts is significantly less influenced by quantitative angiographic parameters. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

First-principles investigation on switching properties of spiropyran and merocyanine grafted graphyne nanotube device

NASA Astrophysics Data System (ADS)

Bhuvaneswari, R.; Nagarajan, V.; Chandiramouli, R.

2018-01-01

The density functional theory (DFT) method with non-equilibrium Green's function (NEGF) method is used to study the electronic properties of the graphyne nanotube device. The graphyne nanotube is used as a base material to graft photochromic spiropyran and merocyanine molecules. The current voltage characteristics clearly give the insights on the switching properties of spiropyran and merocyanine grafted graphyne device. The findings show that spiropyran grafted graphyne device as ON state and merocyanine grafted graphyne device as an OFF state device. Moreover, upon shining light of proper wavelength, the spiropyran/merocyanine grafted graphyne nanotube device can be used as a switch.

Vesicoureteral Reflux in Kidney Transplantation.

PubMed

Molenaar, Nina M; Minnee, Robert C; Bemelman, Frederike J; Idu, Mirza M

2017-06-01

Vesicoureteral reflux (VUR) is frequently found after transplantation, but its impact on graft function, urine tract infection, and graft loss remains uncertain. Therefore our objective was to evaluate the effects of VUR on the outcome of renal transplantation. We included 1008 adult renal transplant recipients of whom a 1-week posttransplant voiding cystourethrogram was available. Study end points included occurrence of bacteriuria, renal function, and graft survival. In total, 106 (10.5%) of 1008 graft recipients had a diagnosis of VUR on voiding cystography. The incidence of bacteriuria was comparable in the reflux and nonreflux group (17% vs 17.4%, P = .91). There was no significant difference in renal function at 3 months and 1 year in patients with and without VUR. One- and 5-year graft survival in patients with VUR was 85.8% and 82.1% compared to 87.3% and 83.0% in patients without VUR ( P = .68 and P = .80). Posttransplant VUR has no correlations with early bacteriuria, renal function, and graft survival.

Initial in vitro and in vivo evaluation of a self-monitoring prosthetic bypass graft.

PubMed

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

2017-06-01

Prosthetic grafts used for lower extremity revascularization and dialysis access fail because of hyperplastic stenosis and thrombosis. Graft surveillance is advocated to monitor function; however, graft failure can occur between episodic examinations. An innovative sensor with wireless, microchip technology allows automated surveillance with assessment of graft function using a "cloud"-based algorithm. We performed proof-of-concept experiments with in vitro and in vivo models to assess the feasibility such a real-time graft surveillance system. A self-monitoring graft system was evaluated consisting of a prosthetic conduit of expanded polytetrafluoroethylene and a sensor unit, and a microsensor, microelectronics, battery, and remote processor with a monitor. The sensor unit was integrated on the extraluminal surface of expanded polytetrafluoroethylene grafts without compromise to the lumen of the conduit. The grafts were tested in vitro in a pulsatile, recirculating flow system under physiologic flow parameters. The hemodynamic parameters were varied to assess the ability to obtain wireless signal acquisition reflecting real-time flow properties in vitro. Segments of custom tubing with reduced diameters were inserted into the model to mimic stenosis proximal and distal to the grafts. After characterization of the initial data, the self-monitoring grafts were implanted in an ovine carotid model to assess proof of concept in vivo with 30-day follow-up of signal acquisition as well as arteriographic and histologic analysis. In vitro flow data demonstrated the device was able to determine factors related to prosthetic graft function under varied hemodynamic flow conditions. Wireless signal acquisition using Bluetooth technology (Bluetooth SIG, Inc, Kirkland, Wash) allowed remote data analysis reflecting graft flow parameters through changes in microsensor voltage and frequency. Waveform analysis was applied to construct an algorithm using proprietary software and determine a parameter for graft flow characteristics. This algorithm allowed determination of the degree of stenosis and location of stenosis location (proximal or distal) for display on a remote monitor in real time. Subsequent in vivo experiments confirmed the ability of the system to generate signal acquisition through skin and soft tissue under biologic conditions with no arteriographic stenosis and a favorable healing response at 30-day harvest. Initial in vitro and in vivo experiments demonstrate the ability for a self-monitoring graft system to remotely monitor hemodynamic parameters reflecting graft function using wireless data transmission. This automated system shows promise to deliver real-time data that can be analyzed by cloud-based algorithms alerting the clinician of a change in graft function or development of stenosis for further diagnostic study or intervention before graft failure. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

RAFT-synthesized Graft Copolymers that Enhance pH-dependent Membrane Destabilization and Protein Circulation Times

PubMed Central

Crownover, Emily; Duvall, Craig L.; Convertine, Anthony; Hoffman, Allan S.; Stayton, Patrick S.

2012-01-01

Here we describe a new graft copolymer architecture of poly(propylacrylic acid) (polyPAA) that displays potent pH-dependent, membrane-destabilizing activity and in addition is shown to enhance protein blood circulation kinetics. PolyPAA containing a single telechelic alkyne functionality was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization with an alkyne-functional chain transfer agent (CTA) and coupled to RAFT polymerized poly(azidopropyl methacrylate) (polyAPMA) through azide-alkyne [3+2] Huisgen cycloaddition. The graft copolymers become membrane destabilizing at endosomal pH values and are active at significantly lower concentrations than the linear polyPAA. A biotin terminated polyPAA graft copolymer was prepared by grafting PAA onto polyAPMA polymerized with a biotin functional RAFT CTA. The blood circulation time and biodistribution of tritium labeled avidin conjugated to the polyPAA graft copolymer was characterized along with a clinically utilized 40 kDa branched polyethylene glycol (PEG) also possessing biotin functionalization. The linear and graft polyPAA increase the area under the curve (AUC) over avidin alone by 9 and 12 times, respectively. Furthermore, polyPAA graft copolymer conjugates accumulated in tumor tissue significantly more than the linear polyPAA and the branched PEG conjugates. The collective data presented in this report indicate that the polyPAA graft copolymers exhibit robust pH-dependent, membrane-destabilizing activity, low cytotoxicity and significantly enhance blood circulation time and tumor accumulation. PMID:21699931

Plasma-mediated grafting of poly(ethylene glycol) on polyamide and polyester surfaces and evaluation of antifouling ability of modified substrates.

PubMed

Dong, Baiyan; Jiang, Hongquan; Manolache, Sorin; Wong, Amy C Lee; Denes, Ferencz S

2007-06-19

A simple cold plasma technique was developed to functionalize the surfaces of polyamide (PA) and polyester (PET) for the grafting of polyethylene glycol (PEG) with the aim of reducing biofilm formation. The surfaces of PA and PET were treated with silicon tetrachloride (SiCl4) plasma, and PEG was grafted onto plasma-functionalized substrates (PA-PEG, PET-PEG). Different molecular weights of PEG and grafting times were tested to obtain optimal surface coverage by PEG as monitored by electron spectroscopy for chemical analysis (ESCA). The presence of a predominant C-O peak on the PEG-modified substrates indicated that the grafting was successful. Data from hydroxyl group derivatization and water contact angle measurement also indicated the presence of PEG after grafting. The PEG-grafted PA and PET under optimal conditions had similar chemical composition and hydrophilicity; however, different morphology changes were observed after grafting. Both PA-PEG and PET-PEG surfaces developed under optimal plasma conditions showed about 96% reduction in biofilm formation by Listeria monocytogenes compared with that of the corresponding unmodified substrates. This plasma functionalization method provided an efficient way to graft PEG onto PA and PET surfaces. Because of the high reactivity of Si-Cl species, this method could potentially be applied to other polymeric materials.

Tailor-made functional surfaces: potential elastomeric biomaterials I.

PubMed

Desai, Shrojal; Bodas, Dhananjay; Patil, K R; Patole, Milind; Singh, R P

2003-01-01

In the present investigation, different functional monomers, like hydroxyethyl methacrylate, acrylic acid, N-vinyl pyrrolidone and glycidyl methacrylate, have been grafted onto the surface of EPDM film (approx. 200 microm) using simultaneous photo-grafting (lambda > or = 290 nm) and cold plasma-grafting techniques, to alter the surface properties, such as hydrophilicity and, therefore, biocompatibility. Here, we have carried out simultaneous plasma-grafting, unlike the conventional post plasma-grafting. The effect of different surface grafting techniques on the degree of surface modification and resultant biocompatibility has been investigated. The chemical changes on the polymer backbone are followed from the results of attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS), which shows the peaks corresponding to the functional groups of the monomers grafted onto the film surface. The morphology of the modified surfaces was investigated using scanning electron microscopy (SEM) technique. The induced hydrophilicity and resultant cell compatibility were followed from the water contact angle measurements and in vitro human carcinoma cell adhesion/proliferation tests, respectively. All the grafted samples exhibited variable cell compatibilities depending upon the type of monomer and their degree of grafting; however, always better than the neat samples. Hydroxyethyl methacrylate and acrylic acid showed exceptionally high cell compatibility in terms of cell adhesion and proliferation.

Pediatric living donor liver transplantation for congenital hepatic fibrosis using a mother's graft with von Meyenburg complex: A case report.

PubMed

Yamada, Naoya; Sanada, Yukihiro; Katano, Takumi; Tashiro, Masahisa; Hirata, Yuta; Okada, Noriki; Ihara, Yoshiyuki; Miki, Atsushi; Sasanuma, Hideki; Urahashi, Taizen; Sakuma, Yasunaru; Mizuta, Koichi

2016-11-28

This is the first report of living donor liver transplantation (LDLT) for congenital hepatic fibrosis (CHF) using a mother's graft with von Meyenburg complex. A 6-year-old girl with CHF, who suffered from recurrent gastrointestinal bleeding, was referred to our hospital for liver transplantation. Her 38-year-old mother was investigated as a living donor and multiple biliary hamartoma were seen on her computed tomography and magnetic resonance imaging scan. The mother's liver function tests were normal and she did not have any organ abnormality, including polycystic kidney disease. LDLT using the left lateral segment (LLS) graft from the donor was performed. The donor LLS graft weighed 250 g; the graft recipient weight ratio was 1.19%. The operation and post-operative course of the donor were uneventful and she was discharged on post-operative day (POD) 8. The graft liver function was good, and the recipient was discharged on POD 31. LDLT using a graft with von Meyenburg complex is safe and useful. Long-term follow-up is needed with respect to graft liver function and screening malignant tumors.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novotny, Jiri, E-mail: jino@medicon.cz; Peregrin, Jan H.; Stribrna, Jarmila

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 amore » 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.« less

Serum aminoacylase-1 is a novel biomarker with potential prognostic utility for long-term outcome in patients with delayed graft function following renal transplantation

PubMed Central

Welberry Smith, Matthew P; Zougman, Alexandre; Cairns, David A; Wilson, Michelle; Wind, Tobias; Wood, Steven L; Thompson, Douglas; Messenger, Michael P; Mooney, Andrew; Selby, Peter J; Lewington, Andrew J P; Banks, Rosamonde E

2013-01-01

Early identification and prognostic stratification of delayed graft function following renal transplantation has significant potential to improve outcome. Mass spectrometry analysis of serum samples, before and on day 2 post transplant from five patients with delayed graft function and five with an uncomplicated transplant, identified aminoacylase-1 (ACY-1) as a potential outcome biomarker. Following assay development, analysis of longitudinal samples from an initial validation cohort of 55 patients confirmed that the ACY-1 level on day 1 or 2 was a moderate predictor of delayed graft function, similar to serum creatinine, complementing the strongest predictor cystatin C. A further validation cohort of 194 patients confirmed this association with area under ROC curves (95% CI) for day 1 serum (138 patients) of 0.74 (0.67–0.85) for ACY-1, 0.9 (0.84–0.95) for cystatin C, and 0.93 (0.88–0.97) for both combined. Significant differences in serum ACY-1 levels were apparent between delayed, slow, and immediate graft function. Analysis of long-term follow-up for 54 patients with delayed graft function showed a highly significant association between day 1 or 3 serum ACY-1 and dialysis-free survival, mainly associated with the donor–brain–dead transplant type. Thus, proteomic analysis provides novel insights into the potential clinical utility of serum ACY-1 levels immediately post transplantation, enabling subdivision of patients with delayed graft function in terms of long-term outcome. Our study requires independent confirmation. PMID:23739232

Risk factors for urinary tract infection after renal transplantation and its impact on graft function in children and young adults.

PubMed

Silva, Andres; Rodig, Nancy; Passerotti, Carlo P; Recabal, Pedro; Borer, Joseph G; Retik, Alan B; Nguyen, Hiep T

2010-10-01

Urinary tract infection will develop in 40% of children who undergo renal transplantation. Post-transplant urinary tract infection is associated with earlier graft loss in adults. However, the impact on graft function in the pediatric population is less well-known. Additionally the risk factors for post-transplant urinary tract infection in children have not been well elucidated. The purpose of this study was to assess the relationship between pre-transplant and post-transplant urinary tract infections on graft outcome, and the risk factors for post-transplant urinary tract infection. A total of 87 patients underwent renal transplantation between July 2001 and July 2006. Patient demographics, cause of renal failure, graft outcome, and presence of pre-transplant and post-transplant urinary tract infections were recorded. Graft outcome was based on last creatinine and nephrological assessment. Median followup was 3.12 years. Of the patients 15% had pre-transplant and 32% had post-transplant urinary tract infections. Good graft function was seen in 60% of the patients and 21% had failed function. Graft function did not correlate with a history of pre-transplant or post-transplant urinary tract infection (p >0.2). Of transplanted patients with urological causes of renal failure 57% had post-transplant urinary tract infection, compared to only 20% of those with a medical etiology of renal failure (p <0.001). In this study there was no correlation between a history of urinary tract infection (either before or after transplant) and decreased graft function. History of pre-transplant urinary tract infection was suggestive of urinary tract infection after transplant. Patients with urological causes of renal failure may be at increased risk for post-transplant urinary tract infection. Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Graft failure after allogeneic hematopoietic stem cell transplantation.

PubMed

Ozdemir, Zehra Narli; Civriz Bozdağ, Sinem

2018-04-18

Graft failure is a serious complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) defined as either lack of initial engraftment of donor cells (primary graft failure) or loss of donor cells after initial engraftment (secondary graft failure). Successful transplantation depends on the formation of engrafment, in which donor cells are integrated into the recipient's cell population. In this paper, we distinguish two different entities, graft failure (GF) and poor graft function (PGF), and review the current comprehensions of the interactions between the immune and hematopoietic compartments in these conditions. Factors associated with graft failure include histocompatibility locus antigen (HLA)-mismatched grafts, underlying disease, type of conditioning regimen and stem cell source employed, low stem cell dose, ex vivo T-cell depletion, major ABO incompatibility, female donor grafts for male recipients, disease status at transplantation. Although several approaches have been developed which aimed to prevent graft rejection, establish successful engraftment and treat graft failure, GF remains a major obstacle to the success of allo-HSCT. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) still remains to be the curative treatment option for various non-malignant and malignant hematopoietic diseases. The outcome of allo-HSCT primarily depends on the engraftment of the graft. Graft failure (GF), is a life-threatening complication which needs the preferential therapeutic manipulation. In this paper, we focused on the definitions of graft failure / poor graft function and also we reviewed the current understanding of the pathophysiology, risk factors and treatment approaches for these entities. Copyright © 2018. Published by Elsevier Ltd.

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

PubMed

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

2015-05-01

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

Gum Graft Surgery

MedlinePlus

... gum line and reduce sensitivity. What are the benefits of gum graft surgery? A gum graft can ... improve function or esthetics, patients often receive the benefits of both: a beautiful new smile and improved ...

Elevated alanine aminotransferase (ALT) in the deceased donor: impact on early post-transplant liver allograft function.

PubMed

Mangus, Richard S; Fridell, Jonathan A; Kubal, Chandrashekhar A; Davis, Jason P; Tector, A Joseph

2015-02-01

Serum alanine aminotransferase (ALT) levels are frequently elevated with liver injury and such elevations are common in deceased organ donors. The impact of this injury on early liver allograft function has not been well described. This study analyses the immediate function and 1-year graft and patient survival for liver allografts stratified by peak serum ALT levels in the deceased donor. The on-site organ procurement records for 1348 consecutive deceased liver donors were reviewed (2001–2011). Serum ALT was categorized into three study groups: normal/mild elevation, 0–499 μ/L; moderate elevation, 500–999 μ/L (>10× upper limit of normal) and severe elevation, ≥1000 μ/L (>20× upper limit of normal). Outcomes included early graft function and graft loss, and 1-year graft and patient survival. Distribution of subjects included: normal/mild, 1259 (93%); moderate, 34 (3%) and severe, 55 (4%). Risk of 30-day graft loss for the three study groups was: 72 (6%), 3 (9%) and 3 (6%) (P = 0.74). Graft and patient survival at 1 year for the three groups was: normal/mild, 1031 (87%), 1048 (88%); moderate, 31 (91%), 31 (91%) and severe, 43 (88%), 44 (90%) (P = 0.71, 0.79). Cox proportional hazards modelling of survival while controlling for donor age and recipient model for end-stage liver disease score (MELD) demonstrates no statistically significant difference among the three study groups. This study demonstrates clinical equivalence in early graft function and 1-year graft and patient survival for donor livers with varying peak levels of serum ALT. These donor allografts may, therefore, be utilized successfully.

The Synthesis of Cellulose Graft Copolymers Using Cu(0)-Mediated Polymerization

NASA Astrophysics Data System (ADS)

Donaldson, Jason L.

Cellulose is the most abundant renewable polymer on the planet and there is great interest in expanding its use beyond its traditional applications. However, its hydrophilicity and insolubility in most common solvent systems are obstacles to its widespread use in advanced materials. One way to counteract this is to attach hydrophobic polymer chains to cellulose: this allows the properties of the copolymer to be tailored by the molecular weight, density, and physical properties of the grafts. Two methods were used here to synthesize the graft copolymers: a 'grafting-from' approach, where synthetic chains were grown outward from bromoester moieties on cellulose (Cell-BiB) via Cu(0)-mediated polymerization; and a 'grafting-to' approach, where fully formed synthetic chains with terminal sulfide functionality were added to cellulose acetate with methacrylate functionality (CA-MAA) via thiol-ene Michael addition. The Cell-BiB was synthesized in the ionic liquid 1-butyl-3-methylimidazolium chloride and had a degree of substitution of 1.13. Polymerization from Cell-BiB proceeded at similar but slightly slower rate than an analogous non-polymeric initiator (EBiB). The average graft density of poly(methyl acrylate) chains was 0.71 chains/ring, with a maximum of 1.0 obtained. The graft density when grafting poly(methyl methacrylate) was only 0.15, and this appeared to be due to the slow initiation of BiB groups. Using EBiB to model the reaction and improve the design should allow this to be overcome. Chain extension experiments demonstrated the living behaviour of the polymer. The CA-MAA was synthesized by esterification with methacrylic acid. Reactions of CA-MAA with thiophenol and dodecanethiol resulted in quantitative addition of the thiol to the alkene. The grafts were synthesized by Cu(0)-mediated polymerization from a bifunctional initiator containing a disulfide bond, followed by reduction to sulfides. The synthetic polymers were successfully grafted to CA-MAA but the grafting yield was limited by the low sulfide functionality. Better retention of sulfide functionality is necessary for more efficient grafting.

Penile Inversion Vaginoplasty with or without Additional Full-Thickness Skin Graft: To Graft or Not to Graft?

PubMed

Buncamper, Marlon E; van der Sluis, Wouter B; de Vries, Max; Witte, Birgit I; Bouman, Mark-Bram; Mullender, Margriet G

2017-03-01

Penile inversion vaginoplasty is considered to be the gold standard for gender reassignment surgery in transgender women. The use of additional full-thickness skin graft as neovaginal lining is controversial. Some believe that having extra penile skin for the vulva gives better aesthetic results. Others believe that it gives inferior functional results because of insensitivity and skin graft contraction. Transgender women undergoing penile inversion vaginoplasty were studied prospectively. The option to add full-thickness skin graft is offered in patients where the penile skin length lies between 7 and 12 cm. Neovaginal depth was measured at surgery and during follow-up (3, 13, 26, and 52 weeks postoperatively). Satisfaction with the aesthetic result, neovaginal depth, and dilation regimen during follow-up were recorded. Satisfaction, sexual function, and genital self-image were assessed using questionnaires. A total of 100 patients were included (32 with and 68 without additional full-thickness skin graft). Patient-reported aesthetic outcome, overall satisfaction with the neovagina, sexual function, and genital self-image were not significantly associated with surgical technique. The mean intraoperative neovaginal depth was 13.8 ± 1.4 cm. After 1 year, this was 11.5 ± 2.5 cm. The largest decline (-15 percent) in depth is observed in the first 3 postoperative weeks (p < 0.01). The authors can confirm neither of the suggested arguments, for or against full-thickness skin graft use, in penile inversion vaginoplasty. The additional use of full-thickness skin graft does not influence neovaginal shrinkage, nor does it affect the patient- and physician-reported aesthetic or functional outcome. Therapeutic, IV.

Delayed grafting of fetal CNS tissue into chronic compression lesions of the adult cat spinal cord.

PubMed

Anderson, D K; Reier, P J; Wirth Iii, E D; Theele, D P; Mareci, T; Brown, S A

1991-01-01

This review summarizes a series of experiments involving transplants of embryonic feline CNS tissue into chronic compression lesions of the adult cat spinal cord. Fetal spinal cord (FSC), caudal brainstem (BSt), neocortex (NCx) or a combination of either FSC/NCx or FSC/BSt was transplanted as solid pieces or as a suspension of dissociated cells into the developed cystic cavities produced by static-load compression trauma 2-10 weeks prior to grafting. All cats were immunosuppressed with cyclosporin A and their locomotor function was assessed for 6-30 weeks. Following the period of evaluation, all recipients were perfused with fixative and tissue specimens, taken at the transplantation site, were processed for general histological and/or immunocytochemical analysis. Viable graft tissue was found in all animals with the exception of two cats which showed active rejection of their transplants. All of the viable intraspinal grafts were extensively vascularized and did not show any signs of imminent or on-going tissue rejection. Fetal cat CNS grafts showed an extended maturational phase in that features of immature neural tissue (e.g. a paucity of myelination) were still seen even 6-9 weeks after transplantation. By 20-30 weeks, FSC and BSt grafts had attained a more advanced stage of maturation. Transplants in these chronic lesions were extensively blended with both the gray and white matter of the host spinal cord and could be visualized by magnetic resonance imaging (MRI). MRI could also detect regions of cavitation at the graft-host interface, as well as within some transplants. While preliminary evidence from behavioral studies suggest that the FSC and BSt grafts may improve or spare locomotor function in some recipients, a more rigorous analysis of post-grafting locomotor function is required to determine conclusively the functionality of these transplants.

Targeting survival pathways to create infarct-spanning bridges of human embryonic stem cell-derived cardiomyocytes.

PubMed

Luo, Jun; Weaver, Matthew S; Dennis, James E; Whalen, Elizabeth; Laflamme, Michael A; Allen, Margaret D

2014-12-01

Generating myocyte grafts that bridge across infarcts could maximize their functional impact and best utilize small numbers of stem cells. To date, however, graft survival within acute infarcts has not been feasible. To enhance intrainfarct graft viability, human embryonic stem cell-derived cardiomyocytes (hESC-CMs) were pretreated before implantation with cobalt protoporphyrin (CoPP), a pharmacologic inducer of cytoprotective heme oxygenase-1. After preculturing with CoPP (vs phosphate-buffered saline), hESC-CMs were injected intramyocardially into acutely infarcted rat hearts, using directed injections to span the infarct. A further group received CoPP-pretreated hESC-CMs plus 4 weekly doses of systemic CoPP to prolong exposure to cytoprotectants. Two control groups with infarcts received vehicle-only intramyocardial injections or weekly systemic CoPP without cell therapy. Postinfarct ventricular function was gauged by echocardiography and graft size quantified at 8 weeks by histomorphometry. CoPP-preconditioned hESC-CMs formed stable grafts deep within infarcted myocardium, while grafts without CoPP exposure survived mainly at the infarct periphery. Fractional shortening was improved at 4 and 8 weeks in all hearts receiving cell therapies (P < .01 vs vehicle-only injections). CoPP treatment of both graft hESC-CMs and recipient animals resulted in the largest grafts, highest fractional shortening, preserved wall thickness, and reduced infarct dimensions. Cellular therapy delivered acutely after infarction significantly improved postinfarct ventricular function at 1 and 2 months. CoPP pretreatment of cells resulted in stable hESC-CM grafts within infarcted myocardium. This design enables construction of directionally oriented, infarct-spanning bands of new cardiomyocytes that might further improve functional restoration as engrafted myocytes proliferate and mature. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Structure-function properties of starch graft poly(methyl acrylate)copolymers

USDA-ARS?s Scientific Manuscript database

Spherulites, produced by steam jet-cooking high-amylose starch and oleic acid, were grafted with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafte...

Structure-function properties of starch spherulites grafted with poly(methyl acrylate)

USDA-ARS?s Scientific Manuscript database

Spherulites, produced by steam jet-cooking high-amylose starch and oleic acid, were grafted with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafte...

Inverted Lobes Have Satisfactory Functions Compared With Noninverted Lobes in Lung Transplantation.

PubMed

Kayawake, Hidenao; Chen-Yoshikawa, Toyofumi F; Motoyama, Hideki; Hamaji, Masatsugu; Hijiya, Kyoko; Aoyama, Akihiro; Goda, Yasufumi; Oda, Hiromi; Ueda, Satoshi; Date, Hiroshi

2018-04-01

To overcome the problem of small-for-size grafts in standard living-donor lobar lung transplantation (LDLLT), we developed inverted LDLLT, in which a right lower lobe from 1 donor is implanted as a right graft and another right lower lobe from another donor is implanted as a left graft. We retrospectively analyzed the functions of inverted grafts vs noninverted grafts. Between 2008 and 2015, 64 LDLLTs were performed. Included were 35 LDLLTs whose recipients were adults and monitored for more than 6 months without developing chronic lung allograft dysfunction. Among them, 65 implanted lobes were eligible for this analysis. There were 31 right lower lobes implanted as right grafts (right-to-right group), 7 right lower lobes as inverted left grafts (right-to-left group), and 27 left lower lobes as left grafts (left-to-left group). We evaluated the graft forced vital capacity (G-FVC) and graft volume of the 65 lobes before and 6 months after LDLLT and compared them among the three groups. Preoperatively, G-FVC in the right-to-left group (1,050 mL) was comparable to that in the right-to-right group (1,177 mL) and better than that in the left-to-left group (791 mL, p < 0.01). Six months after LDLLT, G-FVC in the right-to-left group (1,015 mL) remained comparable to that in the right-to-right group (1,001 mL) and better than that in the left-to-left group (713 mL, p = 0.047). The ratio of graft volume 6 months after LDLLT to the preoperative value was comparable. The functions of inverted grafts in inverted LDLLTs were satisfactory compared with those of noninverted grafts. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Novel small interfering RNA-containing solution protecting donor organs in heart transplantation.

PubMed

Zheng, Xiufen; Lian, Dameng; Wong, Arthur; Bygrave, Michael; Ichim, Thomas E; Khoshniat, Mahdieh; Zhang, Xusheng; Sun, Hongtao; De Zordo, Tobias; Lacefield, James C; Garcia, Bertha; Jevnikar, Anthony M; Min, Wei-Ping

2009-09-22

Ischemia/reperfusion injury is a major factor in graft quality and subsequent function in the transplantation setting. We hypothesize that the process of RNA interference may be used to "engineer" a graft to suppress expression of genes associated with inflammation, apoptosis, and complement, which are believed to cause ischemia/reperfusion injury. Such manipulation of pathological gene expression may be performed by treatment of the graft ex vivo with small interfering RNA (siRNA) as part of the preservation procedure. Heart grafts from BALB/c mice were preserved in UW solution (control) or UW solution containing siRNAs targeting tumor necrosis factor-alpha, C3, and Fas genes (siRNA solution) at 4 degrees C for 48 hours and subsequently transplanted into syngeneic recipients. Tumor necrosis factor-alpha, C3, and Fas genes were elevated by ischemia/reperfusion injury after 48 hours of preservation in UW solution. Preservation in siRNA solution knocked down gene expression at the level of messenger RNA and protein in the grafts after transplantation. All grafts preserved in siRNA solution showed strong contraction, whereas grafts preserved in control solution demonstrated no detectable contraction by high-frequency ultrasound scanning. siRNA solution-treated organs exhibited improved histology and diminished neutrophil and lymphocyte infiltration compared with control solution-treated organs. Furthermore, the treated heart grafts retained strong beating up to the end of the observation period (>100 days), whereas all control grafts lost function within 8 days. Incorporation of siRNA into organ storage solution is a feasible and effective method of attenuating ischemia/reperfusion injury, protecting cardiac function, and prolonging graft survival.

FTIR spectroscopy as a tool for nano-material characterization

NASA Astrophysics Data System (ADS)

Baudot, Charles; Tan, Cher Ming; Kong, Jeng Chien

2010-11-01

Covalently grafting functional molecules to carbon nanotubes (CNTs) is an important step to leverage the excellent properties of that nano-fiber in order to exploit its potential in improving the mechanical and thermal properties of a composite material. While Fourier Transform Infra Red (FTIR) spectroscopy can display the various chemical bonding in a material, we found that the existing database in FTIR library does not cover all the bonding information present in functionalized CNTs because the bond between the grafted molecule and the CNT is new in the FTIR study. In order to extend the applicability of FTIR to nano-material, we present a theoretical method to derive FTIR spectroscopy and compare it with our experimental results. In particular, we illustrate a method for the identification of functional molecules grafted on CNTs, and we are able to confirm that the functional molecules are indeed covalently grafted on the CNTs without any alterations to its functional groups.

Doping Level of Boron-Doped Diamond Electrodes Controls the Grafting Density of Functional Groups for DNA Assays.

PubMed

Švorc, Ĺubomír; Jambrec, Daliborka; Vojs, Marian; Barwe, Stefan; Clausmeyer, Jan; Michniak, Pavol; Marton, Marián; Schuhmann, Wolfgang

2015-09-02

The impact of different doping levels of boron-doped diamond on the surface functionalization was investigated by means of electrochemical reduction of aryldiazonium salts. The grafting efficiency of 4-nitrophenyl groups increased with the boron levels (B/C ratio from 0 to 20,000 ppm). Controlled grafting of nitrophenyldiazonium was used to adjust the amount of immobilized single-stranded DNA strands at the surface and further on the hybridization yield in dependence on the boron doping level. The grafted nitro functions were electrochemically reduced to the amine moieties. Subsequent functionalization with a succinic acid introduced carboxyl groups for subsequent binding of an amino-terminated DNA probe. DNA hybridization significantly depends on the probe density which is in turn dependent on the boron doping level. The proposed approach opens new insights for the design and control of doped diamond surface functionalization for the construction of DNA hybridization assays.

Electron-Beam Lithographic Grafting of Functional Polymer Structures from Fluoropolymer Substrates.

PubMed

Gajos, Katarzyna; Guzenko, Vitaliy A; Dübner, Matthias; Haberko, Jakub; Budkowski, Andrzej; Padeste, Celestino

2016-10-07

Well-defined submicrometer structures of poly(dimethylaminoethyl methacrylate) (PDMAEMA) were grafted from 100 μm thick films of poly(ethene-alt-tetrafluoroethene) after electron-beam lithographic exposure. To explore the possibilities and limits of the method under different exposure conditions, two different acceleration voltages (2.5 and 100 keV) were employed. First, the influence of electron energy and dose on the extent of grafting and on the structure's morphology was determined via atomic force microscopy. The surface grafting with PDMAEMA was confirmed by advanced surface analytical techniques such as time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy. Additionally, the possibility of effective postpolymerization modification of grafted structures was demonstrated by quaternization of the grafted PDMAEMA to the polycationic QPDMAEMA form and by exploiting electrostatic interactions to bind charged organic dyes and functional proteins.

Living unrelated donor kidney transplantation--a fourteen-year experience.

PubMed

Ignjatović, Ljiljana; Jovanović, Dragan; Kronja, Goran; Dujić, Aleksandar; Marić, Mihailo; Ignjatović, Dragan; Hrvacević, Rajko; Kovacević, Zoran; Petrović, Milija; Elaković, Dejan; Marenović, Tomislav; Lukić, Zoran; Trkuljić, Miroljub; Stanković, Bratislav; Maksić, Doko; Butorajac, Josip; Colić, Miodrag; Drasković-Pavlović, Biljana; Kapulica-Kuljić, Nada; Drasković, Nada; Misović, Sidor; Stijelja, Borislav; Milović, Novak; Tosevski, Perica; Filipović, Nikola; Romić, Predrag; Jevtić, Miodrag; Drasković, Miroljub; Vavić, Neven; Rabrenović, Violeta; Paunić, Zoran; Radojević, Milorad; Bjelanović, Zoran; Tomić, Aleksandar; Aleksić, Predrag; Kosević, Branko; Mocović, Dejan; Bancević, Vladimir; Magić, Zvonko; Vojvodić, Danilo; Balint, Bela; Ostojić, Gordana; Tukić, Ljiljana; Murgić, Jadranka; Pervulov, Svetozar; Rusović, Sinisa; Sjenicić, Goran; Vesna, Bućan; Milavić-Vujković, Merica; Jandrić, Dusan; Raicević, Ranko; Mijusković, Mirjana; Obrencević, Katarina; Pilcević, Dejan; Cukić, Zoran; Petrović, Marijana; Petrović, Milica; Tadić, Jelena; Terzić, Brankica; Karan, Zeljko; Bokonjić, Dubravko; Dobrić, Silva; Antunović, Mirjana; Bokun, Radmila; Dimitrijević, Jovan; Vukomanović-Djurdjević, Biserka

2010-12-01

In countries without a national organization for retrieval and distribution of organs of the deceased donors, problem of organ shortage is still not resolved. In order to increase the number of kidney transplantations we started with the program of living unrelated - spousal donors. The aim of this study was to compare treatment outcome and renal graft function in patients receiving the graft from spousal and those receiving ghe graft from living related donors. We retrospectively identified 14 patients who received renal allograft from spousal donors between 1996 and 2009 (group I). The control group consisted of 14 patients who got graft from related donor retrieved from the database and matched than with respect to sex, age, kidney disease, immunological and viral pretransplant status, the initial method of the end stage renal disease treatment and ABO compatibility. In the follow-up period of 41 +/- 38 months we recorded immunosuppressive therapy, surgical complications, episodes of acute rejection, CMV infection and graft function, assessed by serum creatinine levels at the beginning and in the end of the follow-up period. All patients had pretransplant negative cross-match. In ABO incompatible patients pretransplant isoagglutinine titer was zero. The patients with a spousal donor had worse HLA matching. There were no significant differences between the groups in surgical, infective, immunological complications and graft function. Two patients from the group I returned to hemodialysis after 82 and 22 months due to serious comorbidities. In spite of the worse HLA matching, graft survival and function of renal grafts from spousal donors were as good as those retrieved from related donors.

Structure-function properties of amylose-oleic acid inclusion complexes grafted with poly(methyl acrylate)

USDA-ARS?s Scientific Manuscript database

Spherulites, produced by steam jet-cooking high-amylose starch and oleic acid, were grafted with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafte...

Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach

PubMed Central

Saeb, Mohammad Reza; Rezaee, Babak; Shadman, Alireza; Formela, Krzysztof; Ahmadi, Zahed; Hemmati, Farkhondeh; Kermaniyan, Tayebeh Sadat; Mohammadi, Yousef

2017-01-01

Abstract Experimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration, and melt-processing time. An in-house code was developed based on artificial neural network that learns and mimics processing torque and grafting of glycidyl methacrylate (GMA) typical vinylic monomer on high-density polyethylene (HDPE). Application of response surface and desirability function enabled concurrent optimization of processing torque and GMA grafting on HDPE, through which we quantified for the first time competition between parallel reactions taking place during melt processing: (i) desirable grafting of GMA on HDPE; (ii) undesirable cross-linking of HDPE. The proposed robust mathematical modeling approach can precisely learn the behavior of grafting reaction of vinylic monomers on polyolefins and be placed into practice in finding exact operating condition needed for efficient grafting of reactive monomers on polyolefins. PMID:29491797

Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach.

PubMed

Saeb, Mohammad Reza; Rezaee, Babak; Shadman, Alireza; Formela, Krzysztof; Ahmadi, Zahed; Hemmati, Farkhondeh; Kermaniyan, Tayebeh Sadat; Mohammadi, Yousef

2017-01-01

Experimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration, and melt-processing time. An in-house code was developed based on artificial neural network that learns and mimics processing torque and grafting of glycidyl methacrylate (GMA) typical vinylic monomer on high-density polyethylene (HDPE). Application of response surface and desirability function enabled concurrent optimization of processing torque and GMA grafting on HDPE, through which we quantified for the first time competition between parallel reactions taking place during melt processing: (i) desirable grafting of GMA on HDPE; (ii) undesirable cross-linking of HDPE. The proposed robust mathematical modeling approach can precisely learn the behavior of grafting reaction of vinylic monomers on polyolefins and be placed into practice in finding exact operating condition needed for efficient grafting of reactive monomers on polyolefins.

Reconstruction of mandibular defects with autogenous bone grafts: a review of 30 cases.

PubMed

Sajid, Malik Ali Hassan; Warraich, Riaz Ahmed; Abid, Hina; Ehsan-ul-Haq, Muhammad; Shah, Khurram Latif; Khan, Zafar

2011-01-01

Multitudes of options are available for reconstruction of functional and cosmetic defects of the mandible, caused by various ailments. At the present time, autogenous bone grafting is the gold standard by which all other techniques of reconstruction of the mandible can be judged. The purpose of this study was to evaluate the outcome of different osseous reconstruction options using autogenous bone grafts for mandibular reconstruction. This Interventional study was conducted at Department of Oral and Maxillofacial Surgery, King Edward Medical University/Mayo Hospital Lahore, from January 2008 to July 2009 including one year follow-up. The study was carried out on thirty patients having bony mandibular defects. They were reconstructed with the autogenous bone grafts from different graft donor sites. On post-operative visits they were evaluated for outcome variables. Success rate of autogenous bone grafts in this study was 90%. Only 10% of the cases showed poor results regarding infection, resorption and graft failure. Autogenous bone grafts, non-vascularised or vascularised, are a reliable treatment modality for the reconstruction of the bony mandibular defects with predictable functional and aesthetic outcome.

Donor Indocyanine Green Clearance Test Predicts Graft Quality and Early Graft Prognosis After Liver Transplantation.

PubMed

Tang, Yunhua; Han, Ming; Chen, Maogen; Wang, Xiaoping; Ji, Fei; Zhao, Qiang; Zhang, Zhiheng; Ju, Weiqiang; Wang, Dongping; Guo, Zhiyong; He, Xiaoshun

2017-11-01

Transplantation centers have given much attention to donor availability. However, no reliable quantitative methods have been employed to accurately assess graft quality before transplantation. Here, we report that the indocyanine green (ICG) clearance test is a valuable index for liver grafts. We performed the ICG clearance test on 90 brain-dead donors within 6 h before organ procurement between March 2015 and November 2016. We also analyzed the relationship between graft liver function and early graft survival after liver transplantation (LT). Our results suggest that the ICG retention rate at 15 min (ICGR15) of donors before procurement was independently associated with 3-month graft survival after LT. The best donor ICGR15 cutoff value was 11.0%/min, and we observed a significant increase in 3-month graft failure among patients with a donor ICGR15 above this value. On the other hand, a donor ICGR15 value of ≤ 11.0%/min could be used as an early assessment index of graft quality because it provides additional information to the transplant surgeon or organ procurement organization members who must maintain or improve organ function to adapt the LT. An ICG clearance test before liver procurement might be an effective quantitative method to predict graft availability and improve early graft prognosis after LT.

Autologous transplantation with fewer fibers repairs large peripheral nerve defects

PubMed Central

Deng, Jiu-xu; Zhang, Dian-yin; Li, Ming; Weng, Jian; Kou, Yu-hui; Zhang, Pei-xun; Han, Na; Chen, Bo; Yin, Xiao-feng; Jiang, Bao-guo

2017-01-01

Peripheral nerve injury is a serious disease and its repair is challenging. A cable-style autologous graft is the gold standard for repairing long peripheral nerve defects; however, ensuring that the minimum number of transplanted nerve attains maximum therapeutic effect remains poorly understood. In this study, a rat model of common peroneal nerve defect was established by resecting a 10-mm long right common peroneal nerve. Rats receiving transplantation of the common peroneal nerve in situ were designated as the in situ graft group. Ipsilateral sural nerves (10–30 mm long) were resected to establish the one sural nerve graft group, two sural nerves cable-style nerve graft group and three sural nerves cable-style nerve graft group. Each bundle of the peroneal nerve was 10 mm long. To reduce the barrier effect due to invasion by surrounding tissue and connective-tissue overgrowth between neural stumps, small gap sleeve suture was used in both proximal and distal terminals to allow repair of the injured common peroneal nerve. At three months postoperatively, recovery of nerve function and morphology was observed using osmium tetroxide staining and functional detection. The results showed that the number of regenerated nerve fibers, common peroneal nerve function index, motor nerve conduction velocity, recovery of myodynamia, and wet weight ratios of tibialis anterior muscle were not significantly different among the one sural nerve graft group, two sural nerves cable-style nerve graft group, and three sural nerves cable-style nerve graft group. These data suggest that the repair effect achieved using one sural nerve graft with a lower number of nerve fibers is the same as that achieved using the two sural nerves cable-style nerve graft and three sural nerves cable-style nerve graft. This indicates that according to the ‘multiple amplification’ phenomenon, one small nerve graft can provide a good therapeutic effect for a large peripheral nerve defect. PMID:29323049

Grafting of activated carbon cloths for selective adsorption

NASA Astrophysics Data System (ADS)

Gineys, M.; Benoit, R.; Cohaut, N.; Béguin, F.; Delpeux-Ouldriane, S.

2016-05-01

Chemical functionalization of an activated carbon cloth with 3-aminophthalic acid and 4-aminobenzoic acid groups by the in situ formation of the corresponding diazonium salt in aqueous acidic solution is reported. The nature and amount of selected functions on an activated carbon surface, in particular the grafted density, were determined by potentiometric titration, elemental analysis and X-ray photoelectron spectroscopy (XPS). The nanotextural properties of the modified carbon were explored by gas adsorption. Functionalized activated carbon cloth was obtained at a discrete grafting level while preserving interesting textural properties and a large porous volume. Finally, the grafting homogeneity of the carbon surface and the nature of the chemical bonding were investigated using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) technique.

[Tissue engineering applied to the trachea as a graft].

PubMed

Barrera-Ramírez, Elisa; Rico-Escobar, Edna; Garrido-Cardona, Rubén E

2016-01-01

Tissue engineering offers, through new technologies, an ex vivo generation of organs and functional tissues as grafts for transplants, for the improvement and substitution of biological functions, with an absence of immunological response. The treatment of extended tracheal lesions is a substitution of the affected segment; nevertheless, the allogeneic transplant has failed and the use of synthetic materials has not had good results. New tissue engineering technology is being developed to offer a tracheal graft for a posterior implantation. The purpose of this article is to review all the methods and components used by the engineering of tissue for tracheal grafts.

Management of sepsis involving expanded polytetrafluoroethylene grafts for hemodialysis access.

PubMed

Bhat, D J; Tellis, V A; Kohlberg, W I; Driscoll, B; Veith, F J

1980-04-01

The incidence and management of infections in 80 polytetrafluoroethylene (PTFE) grafts is reviewed. In a follow-up period of 12 to 30 months, the overall incidence of infection was 19%. In functioning grafts the majority of infections occurred after dialysis puncture or reoperation. With appropriate management, by incision, drainage, and packing of wounds with povidone-iodine solution, it was possible, even in the face of positive blood cultures, to treat four of five localized infections successfully without loss of graft function. Prophylactic antibiotics may be useful in reducing the high incidence of infection associated with secondary operations.

[The application of delayed skin grafting combined traction in severe joint cicatricial contracture].

PubMed

Xu, Zihan; Zhang, Zhenxin; Wang, Benfeng; Sun, Yaowen; Guo, Yadong; Gao, Wenjie; Qin, Gaoping

2014-11-01

To investigate the effect of delayed skin grafting combined traction in severe joint cicatricial contracture. At the first stage, the joint cicatricial contracture was released completely with protection of vessels, nerves and tendons. The wound was covered with allogenetic skin or biomaterials. After skin traction for 7-14 days, the joint could reach the extension position. Then the skin graft was performed on the wound. 25 cases were treated from Mar. 2000 to May. 2013. Primary healing was achieved at the second stage in all the cases. The skin graft had a satisfactory color and elasticity. Joint function was normal. All the patients were followed up for 3 months to 11 years with no hypertrophic scar and contraction relapse, except for one case who didn' t have enough active exercise on shoulder joint. Delayed skin grafting combined traction can effectively increase the skin graft survival rate and improve the joint function recovery.

Forty-Year Follow-up of Full-Thickness Skin Graft After Thermal Burn Injury to the Volar Hand.

PubMed

Weeks, Dexter; Kasdan, Morton L; Wilhelmi, Bradon J

2016-01-01

The hands are commonly affected in severe thermal burn injuries. Resulting contractures lead to significant loss of function. Burn contracture release and skin grafting are necessary to restore hand function. We report a case in which surgical reconstruction of a volar hand burn was performed with full-thickness skin grafting. The patient had a 40-year follow-up to assess the function and cosmesis of the repaired hand. We report a case in which a 15-month-old boy presented after receiving third-degree burns to the left volar hand, including the flexural aspects of the index, long, and ring fingers by placing it on a hot kitchen stove burner. The patient subsequently underwent scar contracture release and full-thickness skin grafting. Eleven years after reconstruction, further contractures developed associated with the patient's growth, which were reconstructed with repeat full-thickness skin graft from the inguinal region. No recurrence was witnessed afterward and 40 years after initial injury, the patient maintains full activities of daily living and use of his hand in his occupation. There is debate regarding the superiority of split-thickness versus full-thickness grafts during reconstruction. Our case strengthens the argument for durability of a full-thickness skin graft following thermal burn injury.

Hypothermic machine perfusion in kidney transplantation.

PubMed

De Deken, Julie; Kocabayoglu, Peri; Moers, Cyril

2016-06-01

This article summarizes novel developments in hypothermic machine perfusion (HMP) as an organ preservation modality for kidneys recovered from deceased donors. HMP has undergone a renaissance in recent years. This renewed interest has arisen parallel to a shift in paradigms; not only optimal preservation of an often marginal quality graft is required, but also improved graft function and tools to predict the latter are expected from HMP. The focus of attention in this field is currently drawn to the protection of endothelial integrity by means of additives to the perfusion solution, improvement of the HMP solution, choice of temperature, duration of perfusion, and machine settings. HMP may offer the opportunity to assess aspects of graft viability before transplantation, which can potentially aid preselection of grafts based on characteristics such as perfusate biomarkers, as well as measurement of machine perfusion dynamics parameters. HMP has proven to be beneficial as a kidney preservation method for all types of renal grafts, most notably those retrieved from extended criteria donors. Large numbers of variables during HMP, such as duration, machine settings and additives to the perfusion solution are currently being investigated to improve renal function and graft survival. In addition, the search for biomarkers has become a focus of attention to predict graft function posttransplant.

Anti-inflammatory thalidomide improves islet grafts survival and functions in a xenogenic environment.

PubMed

Chen, Chunguang; Kuehn, Carina; Bretzel, Reinhard G; Linn, Thomas

2009-07-20

Thalidomide possesses both anti-inflammatory and anti-angiogenic properties. This study investigates its potential application in islet transplantation with a xenogenic transplantation model. Transplantation was performed using C57Bl/6 mice and NMRI nu/nu mice as recipients of porcine islets. Moreover, islet graft vasculature and inflammation were investigated to identify the mechanisms of thalidomide action. In the immunocompetent environment of C57Bl/6 mice, a fast graft rejection was observed. The group treated with thalidomide 200 mg/kg BW per day achieved and maintained euglycemia in the complete observation period for 42 days. The treated mice had more functional islet graft mass with less leukocyte infiltration. The pro-inflammatory TNF-alpha and VEGF content in islet grafted kidneys was significantly lowered by the treatment. By comparison, thalidomide was not effective in improving graft survival in immunocompromised nude mice. It strongly inhibited the VEGF and TNF-alpha-induced endothelial proliferation of isolated pig islets in a dose dependent manner. The magnitude of thalidomide's inhibitory effect was nearly identical to the effect of VEGF- receptor 2 inhibitor SU416 and anti-TNF-receptor 1 neutralizing antibody, and was reversed by sphingosine-1-phosphate. In conclusion, the anti-inflammatory effect of thalidomide improved islet graft survival and function in a transplantation model with a maximum immune barrier.

Nomograms for predicting graft function and survival in living donor kidney transplantation based on the UNOS Registry.

PubMed

Tiong, H Y; Goldfarb, D A; Kattan, M W; Alster, J M; Thuita, L; Yu, C; Wee, A; Poggio, E D

2009-03-01

We developed nomograms that predict transplant renal function at 1 year (Modification of Diet in Renal Disease equation [estimated glomerular filtration rate]) and 5-year graft survival after living donor kidney transplantation. Data for living donor renal transplants were obtained from the United Network for Organ Sharing registry for 2000 to 2003. Nomograms were designed using linear or Cox regression models to predict 1-year estimated glomerular filtration rate and 5-year graft survival based on pretransplant information including demographic factors, immunosuppressive therapy, immunological factors and organ procurement technique. A third nomogram was constructed to predict 5-year graft survival using additional information available by 6 months after transplantation. These data included delayed graft function, any treated rejection episodes and the 6-month estimated glomerular filtration rate. The nomograms were internally validated using 10-fold cross-validation. The renal function nomogram had an r-square value of 0.13. It worked best when predicting estimated glomerular filtration rate values between 50 and 70 ml per minute per 1.73 m(2). The 5-year graft survival nomograms had a concordance index of 0.71 for the pretransplant nomogram and 0.78 for the 6-month posttransplant nomogram. Calibration was adequate for all nomograms. Nomograms based on data from the United Network for Organ Sharing registry have been validated to predict the 1-year estimated glomerular filtration rate and 5-year graft survival. These nomograms may facilitate individualized patient care in living donor kidney transplantation.

Obesity in the Kidney Transplant Process.

PubMed

Ateş, Damla; Cebeci, Fatma

2018-03-01

Obesity, which has become an increasing problem worldwide, poses a risk for kidney transplant recipients both before and after surgery. In this literature review, we studied the effects of obesity before and after kidney transplant. There are numerous studies and different opinions on the effects of obesity on graft function before and after transplant. Obesity prolongs surgery time and the ischemic process. A large cohort study of 11 836 recipients noted a close association between body mass index and delayed renal transplant and delayed graft function. However, another study found that being overweight or obese before transplant did not have any effects over the medium and long term. A 20-year follow-up study indicated that the firstyear body mass index in recipients after renal transplant had a greater effect on graft function and survival than body mass index before transplant. Still, another study found that body mass index had no effects on graft function and survival. In the study, 3-year graft function and mortality rates of morbidly obese people without diabetes, the functional status without dialysis, and living-donor transplant were reported to be much lower than in those with normal weight. In conclusion, there is no consensus on the effects of obesity before and after transplant, and it has been pointed out that more research should be done on this subject.

Ovarian Grafts 10 Days after Xenotransplantation: Folliculogenesis and Recovery of Viable Oocytes

PubMed Central

Campos-Junior, Paulo Henrique Almeida; Alves, Thalys Jair Melo; Dias, Marco Tulio; Assunçao, Carolina Marinho; Munk, Michele; Mattos, Matheus Silvério; Kraemer, Lucas Rocha; Almeida, Brígida Gomes; Russo, Remo Castro; Barcelos, Lucíola; Camargo, Luiz Sérgio Almeida; Viana, Joao Henrique Moreira

2016-01-01

Ovarian xenotransplantation is a promising alternative to preserve fertility of oncologic patients. However, several functional aspects of this procedure remained to be addressed. The aim of this study was evaluate the feasibility of xenotransplantation as a strategy to maintain bovine ovarian grafts and produce oocytes. Adult ovarian cortical pieces were xenotransplanted to the dorsal subcutaneous of female NOD-SCID mice (n = 62). Grafts were recovered ten days after xenotransplantation. Host and graft weights; folliculogenesis progression; blood perfusion, relative gene expression and number of macrophage and neutrophil of xenografts; in vitro developmental competence of graft-derived oocytes were evaluated. Folliculogenesis was supported in the grafts, as indicated by the presence of primordial, primary, secondary, antral, and atretic follicles. The xenografts showed a greater volumetric density of atretic follicles and higher hyperemia and number of host-derived macrophage and neutrophil (P<0.05), when compared to non-grafted fragments. There was a higher blood perfusion under the back skin in the transplantation sites of host animals than in control and non-grafted (P<0.01). BAX and PRDX1 genes were up-regulated, while BCL2, FSHR, IGF1R and IGF2R were down-regulated, when compared to the control (P<0.01). Twenty seven oocytes were successfully harvested from grafts, and some of these oocytes were able to give rise to blastocysts after in vitro fertilization. However, cleavage and blastocyst rates of xenograft derived oocytes were lower than in control (P<0.01). Despite showing some functional modifications, the ovarian xenografts were able to support folliculogenesis and produce functional oocytes. PMID:27362486

Transient hyperglycemia during liver transplantation does not affect the early graft function.

PubMed

Blasi, Annabel; Beltran, Joan; Martin, Nuria; Martinez-Pallí, Graciela; Lozano, Juan J; Balust, Jaume; Torrents, Abigail; Taura, Pilar

2015-01-01

Background and rationale for the study. Hyperglycemia after graft reperfusion is a consistent finding in liver transplantation (LT) that remains poorly studied. We aim to describe its appearance in LT recipients of different types of grafts and its relation to the graft function. 436 LT recipients of donors after brain death (DBD), donors after cardiac death (DCD), and familial amyloidotic polyneuropathy (FAP) donors were reviewed. Serum glucose was measured at baseline, during the anhepatic phase, after graft reperfusion, and at the end of surgery. Early graft dysfunction (EAD) was assessed by Olthoff criteria. Caspase-3, IFN-γ, IL1β, and IL6 gene expression were measured in liver biopsy. The highest increase in glucose levels after reperfusion was observed in FAP LT recipients and the lowest in DCD LT recipients. Glucose level during the anhepatic phase was the only modifiable predictive variable of hyperglycemia after reperfusion. No relation was found between hyperglycemia after reperfusion and EAD. However, recipients with the highest glucose levels after reperfusion tended to achieve the best glucose control at the end of surgery and those who were unable to control the glucose value after reperfusion showed EAD more frequently. The highest levels of caspase-3 were found in recipients with the lowest glucose values after reperfusion. In conclusion, glucose levels increased after graft reperfusion to a different extent according to the donor type. Contrary to general belief, transient hyperglycemia after reperfusion does not appear to impact negatively on the liver graft function and could even be suggested as a marker of graft quality.

Acellular vascular matrix grafts from human placenta chorion: Impact of ECM preservation on graft characteristics, protein composition and in vivo performance.

PubMed

Schneider, Karl H; Enayati, Marjan; Grasl, Christian; Walter, Ingrid; Budinsky, Lubos; Zebic, Gabriel; Kaun, Christoph; Wagner, Anja; Kratochwill, Klaus; Redl, Heinz; Teuschl, Andreas H; Podesser, Bruno K; Bergmeister, Helga

2018-05-29

Small diameter vascular grafts from human placenta, decellularized with either Triton X-100 (Triton) or SDS and crosslinked with heparin were constructed and characterized. Graft biochemical properties, residual DNA, and protein composition were evaluated to compare the effect of the two detergents on graft matrix composition and structural alterations. Biocompatibility was tested in vitro by culturing the grafts with primary human macrophages and in vivo by subcutaneous implantation of graft conduits (n = 7 per group) into the flanks of nude rats. Subsequently, graft performance was evaluated using an aortic implantation model in Sprague Dawley rats (one month, n = 14). In situ graft imaging was performed using MRI angiography. Retrieved specimens were analyzed by electromyography, scanning electron microscopy, histology and immunohistochemistry to evaluate cell migration and the degree of functional tissue remodeling. Both decellularization methods resulted in grafts of excellent biocompatibility in vitro and in vivo, with low immunogenic potential. Proteomic data revealed removal of cytoplasmic proteins with relative enrichment of ECM proteins in decelluarized specimens of both groups. Noteworthy, LC-Mass Spectrometry analysis revealed that 16 proteins were exclusively preserved in Triton decellularized specimens in comparison to SDS-treated specimens. Aortic grafts showed high patency rates, no signs of thrombus formation, aneurysms or rupture. Conduits of both groups revealed tissue-specific cell migration indicative of functional remodeling. This study strongly suggests that decellularized allogenic grafts from the human placenta have the potential to be used as vascular replacement materials. Both detergents produced grafts with low residual immunogenicity and appropriate mechanical properties. Observed differences in graft characteristics due to preservation method had no impact on successful in vivo performance in the rodent model. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Randomized 2x2 Factorial Clinical Trial of Renal Transplantation: Steroid-Free Maintenance Immunosuppression with Calcineurin Inhibitor Withdrawal after Six Months Associates with Improved Renal Function and Reduced Chronic Histopathology.

PubMed

Stevens, R Brian; Foster, Kirk W; Miles, Clifford D; Kalil, Andre C; Florescu, Diana F; Sandoz, John P; Rigley, Theodore H; Malik, Tamer; Wrenshall, Lucile E

2015-01-01

The two most significant impediments to renal allograft survival are rejection and the direct nephrotoxicity of the immunosuppressant drugs required to prevent it. Calcineurin inhibitors (CNI), a mainstay of most immunosuppression regimens, are particularly nephrotoxic. Until less toxic antirejection agents become available, the only option is to optimize our use of those at hand. To determine whether intensive rabbit anti-thymocyte globulin (rATG) induction followed by CNI withdrawal would individually or combined improve graft function and reduce graft chronic histopathology-surrogates for graft and, therefore, patient survival. As previously reported, a single large rATG dose over 24 hours was well-tolerated and associated with better renal function, fewer infections, and improved patient survival. Here we report testing whether complete CNI discontinuation would improve renal function and decrease graft pathology. Between April 20, 2004 and 4-14-2009 we conducted a prospective, randomized, non-blinded renal transplantation trial of two rATG dosing protocols (single dose, 6 mg/kg vs. divided doses, 1.5 mg/kg every other day x 4; target enrollment = 180). Subsequent maintenance immunosuppression consisted of tacrolimus, a CNI, and sirolimus, a mammalian target of rapamycin inhibitor. We report here the outcome of converting patients after six months either to minimized tacrolimus/sirolimus or mycophenolate mofetil/sirolimus. Primary endpoints were graft function and chronic histopathology from protocol kidney biopsies at 12 and 24 months. CNI withdrawal (on-treatment analysis) associated with better graft function (p <0.001) and lower chronic histopathology composite scores in protocol biopsies at 12 (p = 0.003) and 24 (p = 0.013) months, without affecting patient (p = 0.81) or graft (p = 0.93) survival, or rejection rate (p = 0.17). CNI (tacrolimus) withdrawal at six months may provide a strategy for decreased nephrotoxicity and improved long-term function in steroid-free low immunological risk renal transplant patients. ClinicalTrials.gov NCT00556933.

[Pituitary function of dysgenesic femal rats. Studies with grafting method].

PubMed

Vanhems, E; Busquet, J

1975-01-01

Misulban administered to pregnant rats on the 15th day of gestation provoked gonadal dysgenesia in the offspring. Study of the pituitary function of dysgenesic female rats, realized by grafting method, showed gonadotrophic hypersecretion.

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.

Chitin biological absorbable catheters bridging sural nerve grafts transplanted into sciatic nerve defects promote nerve regeneration.

PubMed

Wang, Zhi-Yong; Wang, Jian-Wei; Qin, Li-Hua; Zhang, Wei-Guang; Zhang, Pei-Xun; Jiang, Bao-Guo

2018-06-01

To investigate the efficacy of chitin biological absorbable catheters in a rat model of autologous nerve transplantation. A segment of sciatic nerve was removed to produce a sciatic nerve defect, and the sural nerve was cut from the ipsilateral leg and used as a graft to bridge the defect, with or without use of a chitin biological absorbable catheter surrounding the graft. The number and morphology of regenerating myelinated fibers, nerve conduction velocity, nerve function index, triceps surae muscle morphology, and sensory function were evaluated at 9 and 12 months after surgery. All of the above parameters were improved in rats in which the nerve graft was bridged with chitin biological absorbable catheters compared with rats without catheters. The results of this study indicate that use of chitin biological absorbable catheters to surround sural nerve grafts bridging sciatic nerve defects promotes recovery of structural, motor, and sensory function and improves muscle fiber morphology. © 2018 John Wiley & Sons Ltd.

On-top plasty using a free metacarpal head graft for lengthening of proximal phalanx in symbrachydactyly--a case report.

PubMed

Iba, Kousuke; Wada, Takuro; Yamashita, Toshihiko

2013-01-01

A three-year old patient with symbrachydactyly (didactyly type) presented with a little finger that was too short to allow pinching and consisting of a floppy soft-tissue envelope with hypoplastic phalanges, although the thumb was functional. As the proximal phalanx was too small to permit distraction lengthening or conventional bone grafting, on-top plasty using a 4th metacarpal graft with a cartilage head was undertaken for lengthening the proximal phalanx of the little finger for pinch reconstruction. At ten weeks after surgery, the patient achieved satisfactory pinch function due to the lengthened and bone-stabilised postoperative digit and reconstruction of functional proximal interphalangeal joint. In addition, the grafted metacarpal demonstrated satisfactory bone growth throughout the six-year follow-up period.

Adipose tissue-derived stem cell-seeded small intestinal submucosa for tunica albuginea grafting and reconstruction

PubMed Central

Ma, Limin; Yang, Yijun; Sikka, Suresh C.; Kadowitz, Philip J.; Ignarro, Louis J.; Abdel-Mageed, Asim B.; Hellstrom, Wayne J. G.

2012-01-01

Porcine small intestinal submucosa (SIS) has been widely used in tunica albuginea (TA) reconstructive surgery. Adipose tissue-derived stem cells (ADSCs) can repair damaged tissue, augment cellular differentiation, and stimulate release of multiple growth factors. The aim of this rat study was to assess the feasibility of seeding ADSCs onto SIS grafts for TA reconstruction. Here, we demonstrate that seeding syngeneic ADSCs onto SIS grafts (SIS-ADSC) resulted in significant cavernosal tissue preservation and maintained erectile responses, similar to controls, in a rat model of bilateral incision of TA, compared with sham-operated animals and rats grafted with SIS graft (SIS) alone. In addition to increased TGF-β1 and FGF-2 expression levels, cross-sectional studies of the rat penis with SIS and SIS-ADSC revealed mild to moderate fibrosis and an increase of 30% and 40% in mean diameter in flaccid and erectile states, respectively. SIS grafting induced transcriptional up-regulation of iNOS and down-regulation of endothelial NOS, neuronal NOS, and VEGF, an effect that was restored by seeding ADCSs on the SIS graft. Taken together, these data show that rats undergoing TA incision with autologous SIS-ADSC grafts maintained better erectile function compared with animals grafted with SIS alone. This study suggests that SIS-ADSC grafting can be successfully used for TA reconstruction procedures and can restore erectile function. PMID:22308363

Prototyped grafting plate for reconstruction of mandibular defects.

PubMed

Zhou, Libin; Wang, Peilin; Han, Haolun; Li, Baowei; Wang, Hongnan; Wang, Gang; Zhao, Jinlong; Liu, Yanpu; Wu, Wei

2014-12-01

To esthetically and functionally restore a 40-mm canine mandibular discontinuity defect using a custom-made titanium bone-grafting plate in combination with autologous iliac bone grafts. Individualized titanium bone-grafting plates were manufactured using a series of techniques, including reverse engineering, computer aided design, rapid prototyping and titanium casting. A 40-mm discontinuous defect in the right mandibular body was created in 9 hybrid dogs. The defect was restored immediately using the customized plate in combination with autologous cancellous iliac blocks. Sequential radionuclide bone imaging was performed to evaluate the bone metabolism and reconstitution of the grafts. The specimens were evaluated by biomechanical testing, 3-dimensional microcomputed tomographic scanning, and histological examination. The results revealed that the symmetry of the mandibles was reconstructed using the customized grafting plate, and the bony continuity of the mandibles was restored. By 12 weeks after the operation, the cancellous iliac grafts became a hard bone block, which was of comparable strength to native mandibles. A fibrous tissue intermediate was found between the remodelled bone graft and the titanium plate. The results indicate that the prototyped grafting plate can be used to restore mandibular discontinuous defects, and satisfactory aesthetical and functional reconstruction can be achieved. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Magnetic imaging of cyanide-bridged co-ordination nanoparticles grafted on FIB-patterned Si substrates.

PubMed

Ghirri, Alberto; Candini, Andrea; Evangelisti, Marco; Gazzadi, Gian Carlo; Volatron, Florence; Fleury, Benoit; Catala, Laure; David, Christophe; Mallah, Talal; Affronte, Marco

2008-12-01

Prussian blue CsNiCr nanoparticles are used to decorate selected portions of a Si substrate. For successful grafting to take place, the Si surface needs first to be chemically functionalized. Low-dose focused ion beam patterning on uniformly functionalized surfaces selects those portions that will not participate in the grafting process. Step-by-step control is assured by atomic force and high-resolution scanning electron microscopy, revealing a submonolayer distribution of the grafted nanoparticles. By novel scanning Hall-probe microscopy, an in-depth investigation of the magnetic response of the nanoparticles to varying temperature and applied magnetic field is provided. The magnetic images acquired suggest that low-temperature canted ferromagnetism is found in the grafted nanoparticles, similar to what is observed in the equivalent bulk material.

Influence of polymer architecture on antigens camouflage, CD47 protection and complement mediated lysis of surface grafted red blood cells.

PubMed

Chapanian, Rafi; Constantinescu, Iren; Rossi, Nicholas A A; Medvedev, Nadia; Brooks, Donald E; Scott, Mark D; Kizhakkedathu, Jayachandran N

2012-11-01

Hyperbranched polyglycerol (HPG) and polyethylene glycol (PEG) polymers with similar hydrodynamic sizes in solution were grafted to red blood cells (RBCs) to investigate the impact of polymer architecture on the cell structure and function. The hydrodynamic sizes of polymers were calculated from the diffusion coefficients measured by pulsed field gradient NMR. The hydration of the HPG and PEG was determined by differential scanning calorimetry analyses. RBCs grafted with linear PEG had different properties compared to the compact HPG grafted RBCs. HPG grafted RBCs showed much higher electrophoretic mobility values than PEG grafted RBCs at similar grafting concentrations and hydrodynamic sizes indicating differences in the structure of the polymer exclusion layer on the cell surface. PEG grafting impacted the deformation properties of the membrane to a greater degree than HPG. The complement mediated lysis of the grafted RBCs was dependent on the type of polymer, grafting concentration and molecular size of grafted chains. At higher molecular weights and graft concentrations both HPG and PEG triggered complement activation. The magnitude of activation was higher with HPG possibly due to the presence of many hydroxyl groups per molecule. HPG grafted RBCs showed significantly higher levels of CD47 self-protein accessibility than PEG grafted RBCs at all grafting concentrations and molecular sizes. PEG grafted polymers provided, in general, a better shielding and protection to ABO and minor antigens from antibody recognition than HPG polymers, however, the compact HPGs provided greater protection of certain antigens on the RBC surface. Our data showed that HPG 20 kDa and HPG 60 kDa grafted RBCs exhibited properties that are more comparable to the native RBC than PEG 5 kDa and PEG 10 kDa grafted RBCs of comparable hydrodynamic sizes. The study shows that small compact polymers such as HPG 20 kDa have a greater potential in the generation of functional RBC for therapeutic delivery applications. The intermediate sized polymers (PEG or HPG) which showed greater antigen camouflage at lower grafting concentrations have significant potential in transfusion as universal red blood donor cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Durability of small-for-size living donor allografts.

PubMed

Au, Kin Pan; Chan, See Ching; Chok, Kenneth Siu Ho; Chan, Albert Chi Yan; Wong, Tiffany Cho Lam; Sharr, William Wei; Lo, Chung Mau

2015-11-01

Our aim was to study the long-term outcomes of living donor liver transplantation using small-for-size (SFS) grafts. From July 2002 to July 2009, 233 patients received a right liver graft with a middle hepatic vein from a living donor in our center. Recipients were stratified according to the graft weight to recipient standard liver volume (GW/SLV) ratio into 4 groups: >50% (n = 89), >40% to 50% (n = 85), >35% to 40% (n = 38), and ≤ 35% (n = 21). They were compared in terms of graft survivals, biliary stricture rates, renal function in terms of estimated glomerular filtration rate (eGFR), platelet counts, and graft function in terms of serum bilirubin and international normalized ratio (INR). The 5-year graft survivals for patients with GW/SLV of >50%, >40% to 50%, >35% to 40% and ≤ 35% were 88.8%, 88.2%, 81.5%, and 81.0%, respectively. Transplantation for hepatocellular carcinoma affected graft survivals (P = 0.02), but graft size did not (P = 0.66). There were no differences in frequency of biliary stricture (21.3% versus 17.1% versus 21.1% versus 28.6%; P = 0.75). At each year after transplant, their platelet counts (P = 0.12-0.65), eGFR (P = 0.49-0.91), bilirubin (P = 0.14-0.51), and INR (P = 0.20-0.98) remained comparable. SFS grafts with GW/SLV ≤ 35% and >35% to 40% had comparable long-term outcomes with larger liver grafts. Graft size did not affect long-term graft survivals. © 2015 American Association for the Study of Liver Diseases.

Significance of Portal Venous Velocity in Short-term Graft Function in Living Donor Liver Transplantation.

PubMed

Wakiyama, S; Takano, Y; Shiba, H; Gocho, T; Sakamoto, T; Ishida, Y; Yanaga, K

2017-06-01

Graft regeneration and functional recovery after reperfusion of transplanted graft are very important for successful living donor liver transplantation (LDLT). The aim of this study was to evaluate the significance of postoperative portal venous velocity (PVV) in short-term recovery of graft function in LDLT. From February 2007 through December 2015, we performed 17 primary LDLTs, which were included in the present study. The patients ranged in age from 12 to 65 years (mean: 50 years), and 11 were female patients. Postoperatively, Doppler ultrasonography was performed daily to measure PVV (cm/s), and liver function parameters were measured daily. The change in PVV (ΔPVV) was defined as follows: ΔPVV = PVV on postoperative day (POD) 1 - PVV on POD 7. Maximal value of serum aspartate aminotransferase (ASTmax) and maximal value of serum alanine transaminase (ALTmax) at 24 hours after graft reperfusion were used as parameters of reperfusion injury. Correlation analyses were performed as follows: (1) correlation of ΔPVV and PVV on POD 1 (PVV-POD 1) with the values such as ASTmax, ALTmax, other liver function parameters on POD 7 and graft regeneration rate; (2) correlation of ASTmax and ALTmax with other liver function parameters on POD 7. ΔPVV significantly correlated with the values of serum total bilirubin (P < .01), prothrombin time (P < .01), and platelet count (P < .05), and PVV-POD 1 significantly correlated with the values of serum total bilirubin (P < .05) and prothrombin time (P < .05). ΔPVV and PVV-POD 1 may be useful parameters of short-term functional recovery of the transplant liver in LDLT. Copyright © 2017 Elsevier Inc. All rights reserved.

Zebrafish enpp1 mutants exhibit pathological mineralization, mimicking features of generalized arterial calcification of infancy (GACI) and pseudoxanthoma elasticum (PXE).

PubMed

Apschner, Alexander; Huitema, Leonie F A; Ponsioen, Bas; Peterson-Maduro, Josi; Schulte-Merker, Stefan

2014-07-01

In recent years it has become clear that, mechanistically, biomineralization is a process that has to be actively inhibited as a default state. This inhibition must be released in a rigidly controlled manner in order for mineralization to occur in skeletal elements and teeth. A central aspect of this concept is the tightly controlled balance between phosphate, a constituent of the biomineral hydroxyapatite, and pyrophosphate, a physiochemical inhibitor of mineralization. Here, we provide a detailed analysis of a zebrafish mutant, dragonfish (dgf), which is mutant for ectonucleoside pyrophosphatase/phosphodiesterase 1 (Enpp1), a protein that is crucial for supplying extracellular pyrophosphate. Generalized arterial calcification of infancy (GACI) is a fatal human disease, and the majority of cases are thought to be caused by mutations in ENPP1. Furthermore, some cases of pseudoxanthoma elasticum (PXE) have recently been linked to ENPP1. Similar to humans, we show here that zebrafish enpp1 mutants can develop ectopic calcifications in a variety of soft tissues - most notably in the skin, cartilage elements, the heart, intracranial space and the notochord sheet. Using transgenic reporter lines, we demonstrate that ectopic mineralizations in these tissues occur independently of the expression of typical osteoblast or cartilage markers. Intriguingly, we detect cells expressing the osteoclast markers Trap and CathepsinK at sites of ectopic calcification at time points when osteoclasts are not yet present in wild-type siblings. Treatment with the bisphosphonate etidronate rescues aspects of the dgf phenotype, and we detected deregulated expression of genes that are involved in phosphate homeostasis and mineralization, such as fgf23, npt2a, entpd5 and spp1 (also known as osteopontin). Employing a UAS-GalFF approach, we show that forced expression of enpp1 in blood vessels or the floorplate of mutant embryos is sufficient to rescue the notochord mineralization phenotype. This indicates that enpp1 can exert its function in tissues that are remote from its site of expression. © 2014. Published by The Company of Biologists Ltd.

Cartilage grafting in nasal reconstruction.

PubMed

Immerman, Sara; White, W Matthew; Constantinides, Minas

2011-02-01

Nasal reconstruction after resection for cutaneous malignancies poses a unique challenge to facial plastic surgeons. The nose, a unique 3-D structure, not only must remain functional but also be aesthetically pleasing to patients. A complete understanding of all the layers of the nose and knowledge of available cartilage grafting material is necessary. Autogenous material, namely septal, auricular, and costal cartilage, is the most favored material in a free cartilage graft or a composite cartilage graft. All types of material have advantages and disadvantages that should guide the most appropriate selection to maximize the functional and cosmetic outcomes for patients. Copyright © 2011 Elsevier Inc. All rights reserved.

Treating fat grafts with human endothelial progenitor cells promotes their vascularization and improves their survival in diabetes mellitus.

PubMed

Hamed, Saher; Ben-Nun, Ohad; Egozi, Dana; Keren, Aviad; Malyarova, Nastya; Kruchevsky, Danny; Gilhar, Amos; Ullmann, Yehuda

2012-10-01

Bone marrow-derived endothelial progenitor cells are required for vascularization of a fat graft to form a functional microvasculature within the graft and to facilitate its integration into the surrounding tissues. Organ transplantation carries a high risk of graft loss and rejection in patients with diabetes mellitus because endothelial progenitor cell function is impaired. The authors investigated the influence of endothelial progenitor cell treatment on the phenotype and survival of human fat grafts in immunocompromised mice with experimentally induced diabetes mellitus. The authors injected 1 ml of human fat tissue into the scalps of 14 nondiabetic and 28 diabetic immunocompromised mice, and then treated some of the grafts with endothelial progenitor cells that was isolated from the blood of a human donor. The phenotype of the endothelial progenitor cell-treated fat grafts from the 14 diabetic mice was compared with that of the untreated fat grafts from 14 nondiabetic and 14 diabetic mice, 18 days and 15 weeks after fat transplantation. Determination of graft phenotype included measurements of weight and volume, vascular endothelial growth factor levels, vascular endothelial growth factor receptor-2, endothelial nitric oxide synthase, and caspase 3 expression levels, and histologic analysis of the extent of vascularization. The untreated grafts from the diabetic mice were fully resorbed 15 weeks after fat transplantation. The phenotype of endothelial progenitor cell-treated fat grafts from the diabetic mice was similar to that of the untreated fat grafts from the nondiabetic mice. Endothelial progenitor cell treatment of transplanted fat can increase the survival of a fat graft by inducing its vascularization and decreasing the extent of apoptosis.

Impact of functional focal versus diffuse coronary artery disease on bypass graft patency.

PubMed

Shiono, Yasutsugu; Kubo, Takashi; Honda, Kentaro; Katayama, Yosuke; Aoki, Hiroshi; Satogami, Keisuke; Kashiyama, Kuninobu; Taruya, Akira; Nishiguchi, Tsuyoshi; Kuroi, Akio; Orii, Makoto; Kameyama, Takeyoshi; Yamano, Takashi; Yamaguchi, Tomoyuki; Matsuo, Yoshiki; Ino, Yasushi; Tanaka, Atsushi; Hozumi, Takeshi; Nishimura, Yoshiharu; Okamura, Yoshitaka; Akasaka, Takashi

2016-11-01

Pressure guidewire pullback recording can differentiate between functional focal and diffuse disease types in coronary artery disease. The aim of this study was to compare the outcome of coronary artery bypass graft (CABG) patency between patients with functional focal versus diffuse disease types in recipient coronary arteries. We investigated 89 patients who underwent pressure guidewire pullback in the left anterior descending (LAD) artery before CABG using internal mammary artery (IMA). Based on the pressure guidewire pullback data, the LAD lesions were classified into functional focal disease (abrupt pressure step-up; n=58) or functional diffuse disease (gradual pressure increase; n=31). Follow-up computed tomography (CT) angiography was conducted within 1year after CABG to assess the bypass graft patency. Pre CABG, LAD angiographic percent diameter stenosis (57±10% vs. 54±12%, p=0.228) and fractional flow reserve (FFR) (0.68±0.07 vs. 0.69±0.07, p=0.244) were not different between the functional focal and diffuse disease groups. The CABG procedure characteristics were similarly comparable between the two groups. In the follow-up CT angiography after CABG, occlusion or string sign of the IMA graft to LAD was more frequently observed in the functional diffuse disease group than in the functional focal disease group (26% vs. 7%, p=0.021). In CABG, functional diffuse disease in the recipient coronary artery was associated with an increased risk of the graft failure in comparison with functional focal disease. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Case Report of Relay Liver Transplantation With Graft Infected With Hepatitis B Virus.

PubMed

Wong, T C L; She, W H; Cheung, T T; Chan, S C; Lo, C M

2015-11-01

Reuse of liver graft for transplantation is extremely uncommon. We report the 1st case of reuse of liver graft from a recipient who had hepatitis B virus (HBV) infection, 11 years after the 1st transplantation. Our relay liver transplantation challenged conventional thinking because of late reuse of graft in the presence of HBV infection. Moreover, both the 1st and the 2nd donors were of advanced age. The key questions were whether the liver graft could be reused safely, especially in the setting of HBV infection, and technical concerns during organ procurement and implantation. The absence of HBV replication was confirmed with negative hepatitis B surface antigen and undetectable serum HBV DNA in the 2nd donor. Based on our experience in managing HBV infection after liver transplantation, we were confident that the adequately suppressed HBV infection in the donor would not jeopardize graft function and that the graft would be able to withstand another ischemia-perfusion injury to continue to function well in our recipient. Copyright © 2015 Elsevier Inc. All rights reserved.

Dynamics and conformations of PEO chains chemically bonded on silica: comparison between 1H and 2H NMR.

PubMed

Tajouri, T; Hommel, H

2007-06-01

1H NMR was used to study the motion of monomer units in a layer of poly(ethylene oxide) chains grafted on silica. First, the dependence of the relaxation times on the grafting ratios is discussed qualitatively from a phenomenological point of view. Next, the NMR line narrowing effect by high-speed rotation is observed in the same samples with different grafting ratios. The magic angle spinning technique permits determination of two correlation times for each grafting ratio: tau(c) characteristic of an environment with a fast motion and tau(l) characteristic of an environment with a slow motion. In addition, the dynamics of these grafted chains are investigated by deuterium NMR (2H NMR), which is sensitive to the anisotropy of molecular motion. The evolution has been studied for two extreme grafting ratios and each time as a function of temperature. The anisotropy is more marked at low temperatures and for a low grafting ratio. The results are consistent with the 1H NMR relaxation times measured as a function of temperature. Copyright 2007 John Wiley & Sons, Ltd.

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

The effect of cerebellar transplantation and enforced physical activity on motor skills and spatial learning in adult Lurcher mutant mice.

PubMed

Cendelín, Jan; Korelusová, Ivana; Vozeh, Frantisek

2009-03-01

Lurcher mutant mice represent a model of olivocerebellar degeneration. They are used to investigate cerebellar functions, consequences of cerebellar degeneration and methods of therapy influencing them. The aim of the work was to assess the effect of foetal cerebellar graft transplantation, repeated enforced physical activity and the combination of both these types of treatment on motor skills, spontaneous motor activity and spatial learning ability in adult B6CBA Lurcher mice. Foetal cerebellar grafts were applied into the cerebellum of Lurchers in the form of solid tissue pieces. Enforced motor activity was realised through rotarod training. Motor functions were examined using bar, ladder and rotarod tests. Spatial learning was tested in the Morris water maze. Spontaneous motor activity in the open field was observed. The presence of the graft was examined histologically. Enforced physical activity led to moderate improvement of some motor skills and to a significant amelioration of spatial learning ability in Lurchers. The transplantation of cerebellar tissue did not influence motor functions significantly but led to an improvement of spatial learning ability. Mutual advancement of the effects of both types of treatment was not observed. Spontaneous motor activity was influenced neither by physical activity nor by the transplantation. Physical activity did not influence the graft survival and development. Because nerve sprouting and cell migration from the graft to the host cerebellum was poor, the functional effects of the graft should be explained with regard to its trophic influence rather than with any involvement of the grafted cells into neural circuitries.

Reversal of diabetes by pancreatic islet transplantation into a subcutaneous, neovascularized device.

PubMed

Pileggi, Antonello; Molano, R Damaris; Ricordi, Camillo; Zahr, Elsie; Collins, Jill; Valdes, Rafael; Inverardi, Luca

2006-05-15

Transplantation of pancreatic islets for the treatment of type 1 diabetes allows for physiologic glycemic control and insulin-independence when sufficient islets are implanted via the portal vein into the liver. Intrahepatic islet implantation requires specific infrastructure and expertise, and risks inherent to the procedure include bleeding, thrombosis, and elevation of portal pressure. Additionally, the relatively higher drug metabolite concentrations in the liver may contribute to the delayed loss of graft function of recent clinical trials. Identification of alternative implantation sites using biocompatible devices may be of assistance improving graft outcome. A desirable bioartificial pancreas should be easy to implant, biopsy, and retrieve, while allowing for sustained graft function. The subcutaneous (SC) site may require a minimally invasive procedure performed under local anesthesia, but its use has been hampered so far by lack of early vascularization, induction of local inflammation, and mechanical stress on the graft. Chemically diabetic rats received syngeneic islets into the liver or SC into a novel biocompatible device consisting of a cylindrical stainless-steel mesh. The device was implanted 40 days prior to islet transplantation to allow embedding by connective tissue and neovascularization. Reversal of diabetes and glycemic control was monitored after islet transplantation. Syngeneic islets transplanted into a SC, neovascularized device restored euglycemia and sustained function long-term. Removal of graft-bearing devices resulted in hyperglycemia. Explanted grafts showed preserved islets and intense vascular networks. Ease of implantation, biocompatibility, and ability to maintain long-term graft function support the potential of our implantable device for cellular-based reparative therapies.

New-onset diabetes mellitus after living-donor liver transplantation: association with graft synthetic function.

PubMed

Yagi, Shintaro; Kaido, Toshimi; Iida, Taku; Yoshizawa, Atsushi; Okajima, Hideaki; Uemoto, Shinji

2017-06-01

It is now known that post-transplant graft function after deceased-donor liver transplantation and living-donor liver transplantation (LDLT) differ; however, there is no report assessing the relationship between graft function and the development of new-onset diabetes mellitus after transplantation (NODAT). We conducted this study to identify the predictive risk factors for NODAT, including graft function after LDLT. The subjects of this study were 175 adult recipients who underwent LDLT at Kyoto University Hospital between 2006 and 2010, and survived for more than 3 months (median observation period, 1046 days). The 1-, 2-, and 3-year incidences of NODAT after LDLT were 26.1, 32.0, and 33.4%, respectively. Pre-transplant diabetes was associated with poor survival (p = 0.0048), whereas NODAT was not associated with patient survival. In the multivariate analysis, recipient age ≥40, a tacrolimus trough level ≥8 ng/mL 3 months after LDLT, and cholinesterase (ChE) <185 IU/L 3 months after LDLT were the independent risk factors for NODAT. Poor graft synthetic function 3 months after LDLT as well as older age of the recipient and a higher tacrolimus concentration were strongly associated with NODAT development after LDLT.

Longitudinal analysis of physical activity, fluid intake, and graft function among kidney transplant recipients

PubMed Central

Gordon, Elisa J.; Prohaska, Thomas R.; Gallant, Mary P.; Sehgal, Ashwini R.; Strogatz, David; Yucel, Recai; Conti, David; Siminoff, Laura A.

2010-01-01

Summary Self-care is recommended to kidney transplant recipients as a vital component to maintain long-term graft function. However, little is known about the effects of physical activity, fluid intake, and smoking history on graft function. This longitudinal study examined the relationship between self-care practices on graft function among 88 new kidney transplant recipients in Chicago, IL and Albany, NY between 2005 and 2008. Participants were interviewed, completed surveys, and medical charts were abstracted. Physical activity, fluid intake, and smoking history at baseline were compared with changes in estimated glomerular filtration rate (eGFR) (every 6 months up to 1 year) using bivariate and multivariate regression analysis, while controlling for sociodemographic and clinical transplant variables. Multivariate analyses revealed that greater physical activity was significantly (P < 0.05) associated with improvement in GFR at 6 months; while greater physical activity, absence of smoking history, and nonwhite ethnicity were significant (P < 0.05) predictors of improvement in GFR at 12 months. These results suggest that increasing physical activity levels in kidney recipients may be an effective behavioral measure to help ensure graft functioning. Our findings suggest the need for a randomized controlled trial of exercise, fluid intake, and smoking history on GFR beyond 12 months. PMID:19619168

Longitudinal analysis of physical activity, fluid intake, and graft function among kidney transplant recipients.

PubMed

Gordon, Elisa J; Prohaska, Thomas R; Gallant, Mary P; Sehgal, Ashwini R; Strogatz, David; Yucel, Recai; Conti, David; Siminoff, Laura A

2009-10-01

Self-care is recommended to kidney transplant recipients as a vital component to maintain long-term graft function. However, little is known about the effects of physical activity, fluid intake, and smoking history on graft function. This longitudinal study examined the relationship between self-care practices on graft function among 88 new kidney transplant recipients in Chicago, IL and Albany, NY between 2005 and 2008. Participants were interviewed, completed surveys, and medical charts were abstracted. Physical activity, fluid intake, and smoking history at baseline were compared with changes in estimated glomerular filtration rate (eGFR) (every 6 months up to 1 year) using bivariate and multivariate regression analysis, while controlling for sociodemographic and clinical transplant variables. Multivariate analyses revealed that greater physical activity was significantly (P < 0.05) associated with improvement in GFR at 6 months; while greater physical activity, absence of smoking history, and nonwhite ethnicity were significant (P < 0.05) predictors of improvement in GFR at 12 months. These results suggest that increasing physical activity levels in kidney recipients may be an effective behavioral measure to help ensure graft functioning. Our findings suggest the need for a randomized controlled trial of exercise, fluid intake, and smoking history on GFR beyond 12 months.

Midterm Results of Renal Transplantation From Controlled Cardiac Death Donors Are Similar to Those From Brain Death Donors.

PubMed

Lafuente, O; Sánchez-Sobrino, B; Pérez, M; López-Sánchez, P; Janeiro, D; Rubio, E; Huerta, A; Marques, M; Llópez-Carratala, M R; Rubio, J J; Portolés, J

2016-11-01

The systematic use of grafts from controlled donors after cardiac death (cDCD) started in our country in 2012 and expanded with the strategic support of National Transplant Organization. We present our experience in kidney transplantation with organs from cDCD donors with a mean follow-up of 3 years. Observational prospective study of all transplants performed in our center in 2012-2013 followed to 2016. The immunosuppression protocols were triple therapy for low-risk recipients from a standard brain death donor (DBD), adding basiliximab or thymoglobulin induction for extended-criteria donor or high-risk recipient, respectively, and thymoglobulin induction plus triple therapy for all cDCD recipients. A total of 42 donors were included (84 grafts in total, but 1 discarded due to multiple cysts); 25 DBD and 17 cDCD without differences in age or sex. The graft use rate was 98.9% for cDCD; 55 grafts were implanted in our hospital (26 DBD and 29 cDCD), and the remaining 28 grafts were transferred to other centers. There were no differences in primary failure (3.4% cDCD vs 7.4% DBD), but the cDCD organs had a higher incidence of delayed graft function (51.7% vs 25.9%). Despite that, graft and patient survivals, as well as glomerular filtration rate (66.3 vs 59.6 mL/min) were similar in both groups. Only 1 patient died at home with a functioning graft in the cDCD group. Despite a higher rate of delayed graft function with cDCD, the midterm outcomes are at least similar to those with DBD. The cDCD programs should be promoted to increase the chances of a transplant in our patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Polypeptide Grafted Hyaluronan: Synthesis and Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 additionmore » 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).« less

Anti-Inflammatory Thalidomide Improves Islet Grafts Survival and Functions in a Xenogenic Environment

PubMed Central

Chen, Chunguang; Kuehn, Carina; Bretzel, Reinhard G.; Linn, Thomas

2009-01-01

Thalidomide possesses both anti-inflammatory and anti-angiogenic properties. This study investigates its potential application in islet transplantation with a xenogenic transplantation model. Transplantation was performed using C57Bl/6 mice and NMRI nu/nu mice as recipients of porcine islets. Moreover, islet graft vasculature and inflammation were investigated to identify the mechanisms of thalidomide action. In the immunocompetent environment of C57Bl/6 mice, a fast graft rejection was observed. The group treated with thalidomide 200 mg/kg BW per day achieved and maintained euglycemia in the complete observation period for 42 days. The treated mice had more functional islet graft mass with less leukocyte infiltration. The pro-inflammatory TNF-α and VEGF content in islet grafted kidneys was significantly lowered by the treatment. By comparison, thalidomide was not effective in improving graft survival in immunocompromised nude mice. It strongly inhibited the VEGF and TNF-α-induced endothelial proliferation of isolated pig islets in a dose dependent manner. The magnitude of thalidomide's inhibitory effect was nearly identical to the effect of VEGF- receptor 2 inhibitor SU416 and anti-TNF-receptor 1 neutralizing antibody, and was reversed by sphingosine-1-phosphate. In conclusion, the anti-inflammatory effect of thalidomide improved islet graft survival and function in a transplantation model with a maximum immune barrier. PMID:19617916

Monolateral dual kidney transplantation from marginal donors.

PubMed

Veroux, M; Corona, D; Gagliano, M; Macarone, M; Sorbello, M; Giuffrida, G; Cutuli, M; Morello, G; Vizcarra, D; Paratore, A; Veroux, P

2007-01-01

Dual kidney transplantation (DKT) offers a safe way to face the organ shortage with good short-term and medium-term renal function. However, its application is limited by the longer operating time and the risk of surgical complication. This study reviews our results with DKT performed with an ipsilateral technique in terms of graft loss, graft and patient survival rates, and surgical complications. From January 2002 to March 2006, 23 patients underwent DKT through a monolateral Gibson incision with placement of both kidneys. One primary nonfunction occurred (4%). Delayed graft function was observed in 3 DKT (13.3%). Acute rejection rate was 4.3% (1 patient). All patients are alive at a mean follow-up of 28 months. One-year and 2-year graft survival rates were 100% and 96%, respectively. Mean serum creatinine level at 1-year posttransplantation was 1.3 mg/dL (range, 0.8-2.1 mg/dL). One DKG recipient lost 1 graft, retaining the second normal functioning graft due to ureteral necrosis. The mean hospital stay after transplantation was 15 days (range, 12-34 days). Monolateral placement in DKT offers the advantage of a single incision, minimizing the surgical risk. Tailored immunosuppression and careful selection of potential recipients, by excluding those with severe cardiopulmonary pathologies, could significantly improve both patient and graft survival in this group of patients.

Graft union formation in tomato plants: peroxidase and catalase involvement.

PubMed

Fernandez-Garcia, Nieves; Carvajal, Micaela; Olmos, Enrique

2004-01-01

The use of grafted plants in vegetable crop production is now being expanded greatly. However, few data are available on the formation of graft unions in vegetables. In this work, the structural development of the graft union formation in tomato plants is studied, together with the possible relationship with activities of peroxidases and catalases. Tomato (Lycopersicon esculentum Mill.) seedlings of cultivar Fanny were grafted on the rootstock of cultivar AR-9704 using the 'tongue approach grafting' method, and were grown in a crop chamber. A study of the structural development of the graft union and the involvement of peroxidases and catalases in the process of graft formation was carried out during the first stages of the graft union (4, 8 and 15 d after grafting). Observation of the structure of the graft union showed formation of xylem and phloem vessels through the graft union 8 d after grafting. In addition, root hydraulic conductance, L0, indicate that the graft union is fully functional 8 d after grafting, which coincided with an increase of peroxidase and catalase activities. These results suggest that increased peroxidase and catalase activities might be implicated in graft development in tomato plants.

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

PubMed

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

2017-09-01

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

The predictive value of the antioxidative function of HDL for cardiovascular disease and graft failure in renal transplant recipients.

PubMed

Leberkühne, Lynn J; Ebtehaj, Sanam; Dimova, Lidiya G; Dikkers, Arne; Dullaart, Robin P F; Bakker, Stephan J L; Tietge, Uwe J F

2016-06-01

Protection of low-density lipoproteins (LDL) against oxidative modification is a key anti-atherosclerotic property of high-density lipoproteins (HDL). This study evaluated the predictive value of the HDL antioxidative function for cardiovascular mortality, all-cause mortality and chronic graft failure in renal transplant recipients (RTR). The capacity of HDL to inhibit native LDL oxidation was determined in vitro in a prospective cohort of renal transplant recipients (RTR, n = 495, median follow-up 7.0 years). The HDL antioxidative functionality was significantly higher in patients experiencing graft failure (57.4 ± 9.7%) than in those without (54.2 ± 11.3%; P = 0.039), while there were no differences for cardiovascular and all-cause mortality. Specifically glomerular filtration rate (P = 0.001) and C-reactive protein levels (P = 0.006) associated independently with antioxidative functionality in multivariate linear regression analyses. Cox regression analysis demonstrated a significant relationship between antioxidative functionality of HDL and graft failure in age-adjusted analyses, but significance was lost following adjustment for baseline kidney function and inflammatory load. No significant association was found between HDL antioxidative functionality and cardiovascular and all-cause mortality. This study demonstrates that the antioxidative function of HDL (i) does not predict cardiovascular or all-cause mortality in RTR, but (ii) conceivably contributes to the development of graft failure, however, not independent of baseline kidney function and inflammatory load. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Microwave based synthesis and spectral characterization of thermo-sensitive poly(N,N-diethylacrylamide) grafted pectin copolymer.

PubMed

Işıklan, Nuran; Tokmak, Şeyma

2018-07-01

The functionalization of polysaccharides with synthetic polymers has attracted great attention owing to its application in many industrial fields. The aim of this work was to study the impact of pectin functionalization with N,N-diethylacrylamide (DEAAm). Pectin was modified via microwave-induced graft copolymerization of DEAAm using ceric ammonium nitrate (CAN) and N,N,N',N'-tetramethylethylenediamine (TEMED). FTIR, 13 C NMR, DSC/TGA, XRD, and SEM techniques were used to verify the structure of graft copolymers. Various reaction conditions such as microwave irradiation time, temperature, microwave power, monomer, initiator, and TEMED concentrations were investigated to get a maximum grafting yield of 192%. Lower critical solution temperatures (LCST) of graft copolymers were determined by UV spectroscopy. Graft copolymers were found to be thermo-sensitive, with LCST of 31°C and high thermal resistance. Biocompatibility test of copolymers showed that copolymers were not cytotoxic to L929 fibroblasts cells and can be used as a biomaterial. Copyright © 2018 Elsevier B.V. All rights reserved.

Engineering of arteries in vitro

PubMed Central

Huang, Angela H.; Niklason, Laura E.

2014-01-01

This review will focus on two elements that are essential for functional arterial regeneration in vitro: the mechanical environment and the bioreactors used for tissue growth. The importance of the mechanical environment to embryological development, vascular functionality, and vascular graft regeneration will be discussed. Bioreactors generate mechanical stimuli to simulate the biomechanical environment of the arterial system. This system has been used to reconstruct arterial grafts with appropriate mechanical strength for implantation by controlling the chemical and mechanical environments in which the grafts are grown. Bioreactors are powerful tools to study the effect of mechanical stimuli on extracellular matrix (ECM) architecture and the mechanical properties of engineered vessels. Hence biomimetic systems enable us to optimize chemo-biomechanical culture conditions to regenerate engineered vessels with physiological properties similar to those of native arterial vessels. In addition, this review will introduce and examine various approaches and techniques that have been used to engineer biologically-based vascular grafts, including collagen-based grafts, fibrin-gel grafts, cell sheet engineering, biodegradable polymers, and decellularization of native vessels. PMID:24399290

Microsurgical reconstruction of large nerve defects using autologous nerve grafts.

PubMed

Daoutis, N K; Gerostathopoulos, N E; Efstathopoulos, D G; Misitizis, D P; Bouchlis, G N; Anagnostou, S K

1994-01-01

Between 1986 and 1993, 643 patients with peripheral nerve trauma were treated in our clinic. Primary neurorraphy was performed in 431 of these patients and nerve grafting in 212 patients. We present the functional results after nerve grafting in 93 patients with large nerve defects who were followed for more than 2 years. Evaluation of function was based on the Medical Research Council (MRC) classification for motor and sensory recovery. Factors affecting functional outcome, such as age of the patient, denervation time, length of the defect, and level of the injury were noted. Good results according to the MRC classification were obtained in the majority of cases, although function remained less than that of the uninjured side.

Methods of Attaching or Grafting Carbon Nanotubes to Silicon Surfaces and Composite Structures Derived Therefrom

NASA Technical Reports Server (NTRS)

Tour, James M. (Inventor); Chen, Bo (Inventor); Flatt, Austen K. (Inventor); Stewart, Michael P. (Inventor); Dyke, Christopher A. (Inventor); Maya, Francisco (Inventor)

2012-01-01

The present invention is directed toward methods of attaching or grafting carbon nanotubes (CNTs) to silicon surfaces. In some embodiments, such attaching or grafting occurs via functional groups on either or both of the CNTs and silicon surface. In some embodiments, the methods of the present invention include: (1) reacting a silicon surface with a functionalizing agent (such as oligo(phenylene ethynylene)) to form a functionalized silicon surface; (2) dispersing a quantity of CNTs in a solvent to form dispersed CNTs; and (3) reacting the functionalized silicon surface with the dispersed CNTs. The present invention is also directed to the novel compositions produced by such methods.

Associations between Deceased-Donor Urine Injury Biomarkers and Kidney Transplant Outcomes

PubMed Central

Reese, Peter P.; Hall, Isaac E.; Weng, Francis L.; Schröppel, Bernd; Doshi, Mona D.; Hasz, Rick D.; Thiessen-Philbrook, Heather; Ficek, Joseph; Rao, Veena; Murray, Patrick; Lin, Haiqun

2016-01-01

Assessment of deceased-donor organ quality is integral to transplant allocation practices, but tools to more precisely measure donor kidney injury and better predict outcomes are needed. In this study, we assessed associations between injury biomarkers in deceased-donor urine and the following outcomes: donor AKI (stage 2 or greater), recipient delayed graft function (defined as dialysis in first week post-transplant), and recipient 6-month eGFR. We measured urinary concentrations of microalbumin, neutrophil gelatinase–associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), IL-18, and liver-type fatty acid binding protein (L-FABP) from 1304 deceased donors at organ procurement, among whom 112 (9%) had AKI. Each biomarker strongly associated with AKI in adjusted analyses. Among 2441 kidney transplant recipients, 31% experienced delayed graft function, and mean±SD 6-month eGFR was 55.7±23.5 ml/min per 1.73 m2. In analyses adjusted for donor and recipient characteristics, higher donor urinary NGAL concentrations associated with recipient delayed graft function (highest versus lowest NGAL tertile relative risk, 1.21; 95% confidence interval, 1.02 to 1.43). Linear regression analyses of 6-month recipient renal function demonstrated that higher urinary NGAL and L-FABP concentrations associated with slightly lower 6-month eGFR only among recipients without delayed graft function. In summary, donor urine injury biomarkers strongly associate with donor AKI but provide limited value in predicting delayed graft function or early allograft function after transplant. PMID:26374609

A joint model for longitudinal and time-to-event data to better assess the specific role of donor and recipient factors on long-term kidney transplantation outcomes.

PubMed

Fournier, Marie-Cécile; Foucher, Yohann; Blanche, Paul; Buron, Fanny; Giral, Magali; Dantan, Etienne

2016-05-01

In renal transplantation, serum creatinine (SCr) is the main biomarker routinely measured to assess patient's health, with chronic increases being strongly associated with long-term graft failure risk (death with a functioning graft or return to dialysis). Joint modeling may be useful to identify the specific role of risk factors on chronic evolution of kidney transplant recipients: some can be related to the SCr evolution, finally leading to graft failure, whereas others can be associated with graft failure without any modification of SCr. Sample data for 2749 patients transplanted between 2000 and 2013 with a functioning kidney at 1-year post-transplantation were obtained from the DIVAT cohort. A shared random effect joint model for longitudinal SCr values and time to graft failure was performed. We show that graft failure risk depended on both the current value and slope of the SCr. Deceased donor graft patient seemed to have a higher SCr increase, similar to patient with diabetes history, while no significant association of these two features with graft failure risk was found. Patient with a second graft was at higher risk of graft failure, independent of changes in SCr values. Anti-HLA immunization was associated with both processes simultaneously. Joint models for repeated and time-to-event data bring new opportunities to improve the epidemiological knowledge of chronic diseases. For instance in renal transplantation, several features should receive additional attention as we demonstrated their correlation with graft failure risk was independent of the SCr evolution.

Use of autologous grafts in the treatment of acquired penile curvature: An experience of 33 cases.

PubMed

Khawaja, Abdul Rouf; Dar, Tanveer Iqbal; Zahur, Suhael; Tariq, Sheikh; Hamid, Arf; Wani, M S; Wazir, B S; Iqbal, Arsheed

2016-01-01

The objective was to compare the use of autologous dermal and temporalis fascia grafts in the treatment of acquired penile curvatures. It was a prospective observational study of 33 cases, conducted in Sher-i-Kashmir Institute of Medical Sciences, Srinagar from March 2007 to September 2013. All the patients had stable Peyronies disease (PD). Dorsal, dorsolateral and vental curvatures with good preoperative erections were included. PD index with visual analog scales for curvature was used preoperatively. An informed written consent was taken from all the patients with main emphasis on erectile dysfunction. After an average follow up of 2 years, complete straightening of penis was observed in all patients with satisfactory sexual intercourse in 30 patients (90%). Three patients (10%) required frequent use of type 5 phosphodiesterase inhibitors for adequate erections. Overall 91% of patients and partners were satisfied with the procedure and cosmetically donor site was better in temporalis fascia graft site. No rejection of any graft was noted and glans hypoesthesia was noticed in 4 patients (12%). None of the patients required penile prosthesis. Total operative time for harvesting and application of the graft was more in dermal grafts (>3 hrs) than for temporalis fascia graft (2 hrs). Tunical lengthening procedures by autologous free grafts represents a safe and reproducible technique. A good preoperative erectile function is required for tunical lengthening procedure. Temporalis fascia graft is thin, tough membrane and effective graft for PD with good cosmetic and functional results.

Primary graft dysfunction of the liver: definitions, diagnostic criteria and risk factors.

PubMed

Neves, Douglas Bastos; Rusi, Marcela Balbo; Diaz, Luiz Gustavo Guedes; Salvalaggio, Paolo

2016-01-01

Primary graft dysfunction is a multifactorial syndrome with great impact on liver transplantation outcomes. This review article was based on studies published between January 1980 and June 2015 and retrieved from PubMed database using the following search terms: "primary graft dysfunction", "early allograft dysfunction", "primary non-function" and "liver transplantation". Graft dysfunction describes different grades of graft ischemia-reperfusion injury and can manifest as early allograft dysfunction or primary graft non-function, its most severe form. Donor-, surgery- and recipient-related factors have been associated with this syndrome. Primary graft dysfunction definition, diagnostic criteria and risk factors differ between studies. RESUMO A disfunção primária do enxerto hepático é uma síndrome multifatorial com grande impacto no resultado do transplante de fígado. Foi realizada uma ampla revisão da literatura, consultando a base de dados PubMed, em busca de estudos publicados entre janeiro de 1980 e junho de 2015. Os termos descritivos utilizados foram: "primary graft dysfunction", "early allograft dysfunction", "primary non-function" e "liver transplantation". A disfunção traduz graus diferentes da lesão de isquemia e reperfusão do órgão, e pode se manifestar como disfunção precoce ou, na forma mais grave, pelo não funcionamento primário do enxerto. Fatores relacionados ao doador, ao transplante e ao receptor contribuem para essa síndrome. Existem definições diferentes na literatura quanto ao diagnóstico e aos fatores de risco associados à disfunção primária.

Lack of functional relevance of isolated cell damage in transplants of Parkinson's disease patients.

PubMed

Cooper, Oliver; Astradsson, Arnar; Hallett, Penny; Robertson, Harold; Mendez, Ivar; Isacson, Ole

2009-08-01

Postmortem analyses from clinical neural transplantation trials of several subjects with Parkinson's disease revealed surviving grafted dopaminergic neurons after more than a decade. A subset of these subjects displayed isolated dopaminergic neurons within the grafts that contained Lewy body-like structures. In this review, we discuss why this isolated cell damage is unlikely to affect the overall graft function and how we can use these observations to help us to understand age-related neurodegeneration and refine our future cell replacement therapies.

Amphiphilic graft copolymers from end-functionalized starches: synthesis, characterization, thin film preparation, and small molecule loading.

PubMed

Ryno, Lisa M; Reese, Cassandra; Tolan, McKenzie; O'Brien, Jeffrey; Short, Gabriel; Sorriano, Gerardo; Nettleton, Jason; Fulton, Kayleen; Iovine, Peter M

2014-08-11

End-functionalized macromolecular starch reagents, prepared by reductive amination, were grafted onto a urethane-linked polyester-based backbone using copper-catalyzed azide-alkyne cycloaddition (CuAAC) chemistry to produce novel amphiphilic hybrid graft copolymers. These copolymers represent the first examples of materials where the pendant chains derived from starch biopolymers have been incorporated into a host polymer by a grafting-to approach. The graft copolymers were prepared in good yields (63-90%) with high grafting efficiencies (66-98%). Rigorous quantitative spectroscopic analyses of both the macromolecular building blocks and the final graft copolymers provide a comprehensive analytical toolbox for deciphering the reaction chemistry. Due to the modular nature of both the urethane-linked polyester synthesis and the postpolymerization modification, the starch content of these novel hybrid graft copolymers was easily tuned from 28-53% (w/w). The uptake of two low molecular weight guest molecules into the hybrid polymer thin films was also studied. It was found that binding of 1-naphthol and pterostilbene correlated linearly with amount of starch present in the hybrid polymer. The newly synthesized graft copolymers were highly processable and thermally stable, therefore, opening up significant opportunities in film and coating applications. These results represent a proof-of-concept system for not only the construction of starch-containing copolymers, but also the loading of these novel polymeric materials with active agents.

Pancreas retransplantation: a second chance for diabetic patients?

PubMed

Buron, Fanny; Thaunat, Olivier; Demuylder-Mischler, Sandrine; Badet, Lionel; Brunet, Maria; Ber, Charles-Eric; Thivolet, Charles; Martin, Xavier; Berney, Thierry; Morelon, Emmanuel

2013-01-27

If pancreas transplantation is a validated alternative for type 1 diabetic patients with end-stage renal disease, the management of patients who have lost their primary graft is poorly defined. This study aims at evaluating pancreas retransplantation outcome. Between 1976 and 2008, 569 pancreas transplantations were performed in Lyon and Geneva, including 37 second transplantations. Second graft survival was compared with primary graft survival of the same patients and the whole population. Predictive factors of second graft survival were sought. Patient survival and impact on kidney graft function and survival were evaluated. Second pancreas survival of the 17 patients transplanted from 1995 was close to primary graft survival of the whole population (71% vs. 79% at 1 year and 59% vs. 69% at 5 years; P=0.5075) and significantly better than their first pancreas survival (71% vs. 29% at 1 year and 59% vs. 7% at 5 years; P=0.0008) regardless of the cause of first pancreas loss. The same results were observed with all 37 retransplantations. Survival of second simultaneous pancreas and kidney transplantations was better than survival of second pancreas after kidney. Patient survival was excellent (89% at 5 years). Pancreas retransplantation had no impact on kidney graft function and survival (100% at 5 years). Pancreas retransplantation is a safe procedure with acceptable graft survival that should be proposed to diabetic patients who have lost their primary graft.

The Association Between Renin-Angiotensin System Blockade and Long-term Outcomes in Renal Transplant Recipients: The Wisconsin Allograft Recipient Database (WisARD).

PubMed

Shin, Jung-Im; Palta, Mari; Djamali, Arjang; Kaufman, Dixon B; Astor, Brad C

2016-07-01

Renin-angiotensin system (RAS) blockade reduces mortality in the general population and among non-dialysis-dependent patients with chronic kidney disease. The RAS blockade also decreases proteinuria and protects renal function in non-transplant patients with chronic kidney disease. It remains controversial, however, whether this translates to improved patient or graft survival among transplant recipients. We analyzed 2684 primary kidney transplant recipients at the University of Wisconsin in 1994 to 2010 who had a functioning graft at 6 months after transplantation. We assessed the association of RAS blockade with patient and graft survival using time-dependent Cox and marginal structural models. Three hundred seventy-seven deaths and 329 graft failures before death (638 total graft losses) occurred during a median of 5.4 years of follow-up. The RAS blockade was associated with an adjusted-hazard ratio of 0.63 (95% confidence interval, 0.53-0.75) for total graft loss, 0.69 (0.55-0.86) for death, and 0.62 (0.49-0.78) for death-censored graft failure. The associations of RAS blockade with a lower risk of total graft loss and mortality were stronger with more severe proteinuria. The RAS blockade was associated with a 2-fold higher risk of hyperkalemia. Our findings suggest RAS blockade is associated with better patient and graft survival in renal transplant recipients.

Half-peroneus-longus-tendon graft augmentation for unqualified hamstring tendon graft of anterior cruciate ligament reconstruction.

PubMed

Liu, Chung-Ting; Lu, Yung-Chang; Huang, Chang-Hung

2015-09-01

In some situations, harvested hamstring tendon grafts are not qualified for anterior cruciate ligament (ACL) reconstruction. This study aimed to present a reinforcing method with additional half peroneus longus tendon (half-PLT) graft augmentation. Eight cases underwent ACL reconstruction with unqualified hamstring tendon grafts (diameter <7 mm) and were salvaged by additional half-PLT graft augmentation. The pivot shift test and KT-1000 tests were performed 3 years after surgery. Functional evaluation of subjective International Knee Documentation Committee (IKDC) and Lysholm scores was also done. In addition, Foot and Ankle Disability Index (FADI) scores were used to evaluate the function of the ankle donor site. The diameter of unqualified four-strand hamstring tendon grafts was 6.2 mm on average (range, 6.0-6.5 mm). The average diameter of hamstring grafts with half-PLT augmentation was 9.6 mm (range, 9.5-10.0 mm). The pivot shift test was negative in all patients. No significant differences between normal and abnormal knees were found by KT-1000. The average IKDC score was 86.0 (range, 83 to 89), and the average Lysholm score was 84.4 (range, 80-90). The average FADI score for the donor sites of half-PLT was 135.8 (range, 134-136). Additional half-PLT can successfully and safely reinforce unqualified hamstring tendon grafts for ACL reconstruction.

Long-term effects of steroid withdrawal in kidney transplantation.

PubMed

Offermann, G; Schwarz, A; Krause, P H

1993-01-01

The long-term graft function after withdrawal of steroids from maintenance immunosuppression was analyzed in 98 kidney recipients (59 on cyclosporin monotherapy, 39 on cyclosporin plus azathioprine) who had not developed an early rejection episode when prednisolone was discontinued. Seven years after steroid withdrawal the probability of an increase in serum creatinine (> 20% of baseline levels) was 51%. The increase in creatinine was associated with sclerosing arteriopathy as a marker of chronic rejection in 29 of 43 graft biopsies. The addition of azathioprine had no effect on the stability of long-term graft function and did not influence the 7-year graft survival rate in this highly selected group of patients.

Metabolomics discloses donor liver biomarkers associated with early allograft dysfunction.

PubMed

Cortes, Miriam; Pareja, Eugenia; García-Cañaveras, Juan C; Donato, M Teresa; Montero, Sandra; Mir, Jose; Castell, José V; Lahoz, Agustín

2014-09-01

Early allograft dysfunction (EAD) dramatically influences graft and patient outcome after orthotopic liver transplantation and its incidence is strongly determined by donor liver quality. Nevertheless, objective biomarkers, which can assess graft quality and anticipate organ function, are still lacking. This study aims to investigate whether there is a preoperative donor liver metabolomic biosignature associated with EAD. A comprehensive metabolomic profiling of 124 donor liver biopsies collected before transplantation was performed by mass spectrometry coupled to liquid chromatography. Donor liver grafts were classified into two groups: showing EAD and immediate graft function (IGF). Multivariate data analysis was used to search for the relationship between the metabolomic profiles present in donor livers before transplantation and their function in recipients. A set of liver graft dysfunction-associated biomarkers was identified. Key changes include significantly increased levels of bile acids, lysophospholipids, phospholipids, sphingomyelins and histidine metabolism products, all suggestive of disrupted lipid homeostasis and altered histidine pathway. Based on these biomarkers, a predictive EAD model was built and further evaluated by assessing 24 independent donor livers, yielding 91% sensitivity and 82% specificity. The model was also successfully challenged by evaluating donor livers showing primary non-function (n=4). A metabolomic biosignature that accurately differentiates donor livers, which later showed EAD or IGF, has been deciphered. The remarkable metabolomic differences between donor livers before transplant can relate to their different quality. The proposed metabolomic approach may become a clinical tool for donor liver quality assessment and for anticipating graft function before transplant. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Raman-based detection of hydroxyethyl starch in kidney allograft biopsies as a potential marker of allograft quality in kidney transplant recipients

NASA Astrophysics Data System (ADS)

Vuiblet, Vincent; Fere, Michael; Bankole, Ezechiel; Wynckel, Alain; Gobinet, Cyril; Birembaut, Philippe; Piot, Olivier; Rieu, Philippe

2016-09-01

In brain-dead donor resuscitation, hydroxyethyl starch (HES) use has been associated with presence of osmotic-nephrosis-like lesions in kidney transplant recipients. Our aim was to determine whether the presence of HES in protocol renal graft biopsies at three months (M3) after transplantation is associated with renal graft quality. According to the HES administered to the donor during the procurement procedure, two groups of patients were defined according graft exposition to HES: HES group, (N = 20) and control group (N = 6). Detection and relative quantification of HES was performed by Raman spectroscopy microimaging on M3 protocol renal graft biopsies. Statistical analyses were used to investigate the association between Raman data and graft characteristics. HES spectral signal was revealed negative in the control group, whereas it was positive in 40% of biopsies from the HES group. In the HES group, a stronger HES signal was associated with a lower risk of graft failure measured by the Kidney Donor Risk Index (KDRI) and was correlated with the allograft kidney function. Thus, HES accumulation in donor kidney, as probed by Raman biophotonic technique, is correlated with the quality of donor kidney and consequently the graft renal function and graft survival.

Upcycling of polypropylene waste by surface modification using radiation-induced grafting

NASA Astrophysics Data System (ADS)

Hassan, Muhammad Inaam ul; Taimur, Shaista; Yasin, Tariq

2017-11-01

In this work, upcycling of polypropylene waste into amidoxime functionalized polypropylene adsorbent was studied using radiation-induced grafting technique. Polypropylene waste (PPw) was resulted from accelerated thermal ageing of polypropylene (PP). Bulk grafting of acrylonitrile (AN) onto PPw was achieved by simultaneous radiation grafting method using gamma rays. Degree of grafting of AN on PPw is affected by absorbed dose and dose rate. The acrylonitrile groups of grafted PPw were chemically converted into amidoxime functionality. Both the acrylonitrile-grafted PP waste and its amidoxime product were investigated by FTIR, XRD, SEM-EDX and TGA techniques. The prepared amidoxime adsorbent with amidoxime group density of 8.06 mmol/g was used for removal of copper ions from aqueous solutions. The effects of various physicochemical conditions such as: solution pH, adsorbent content, initial metal ion concentration and time on adsorption were studied to maximize adsorption of metal ion. Pseudo-first-order, pseudo-second-order and intra-particle diffusion models were applied to study the kinetics of adsorption. Maximum Langmuir adsorption capacity of 208.3 mg/g at pH 5.0 with optimum contact time of 120 min was observed. Utilization of PP waste and its comparable adsorption capacity with existing radiation grafted polymer-based adsorbents provide a new, cheap and cost effective system.

Cadaveric renal preservation with hyperosmolar, intracellular hypothermic washout solution and cold storage.

PubMed

Diethelm, A G; Blackstone, E H

1978-07-01

All 54 kidneys obtained from heart-beating cadavers functioned when preserved by a brief washout using a hypothermic, hyperosmolar, hyperkalemic perfusate, followed by cold storage. The duration of preservation ranged from two hours and 57 minutes to 39 hours and 47 minutes. Two other kidneys retrieved from a nonheart-beating cadaver and preserved by the same technique failed to function because of irreversible acute tubular necrosis. Fifty-six consecutive transplant patients were divided into four groups according to the period of preservation. There was no correlation between graft rejection, frequency of post-transplant dialysis, long term graft function and survival time, when the duration of preservation was less than 24 hours. The advantages of this technique included technical simplicity, low cost, minimal risk of graft infection and easy transportation. The two primary disadvantages were an apparent 24 to 30 hour limit of organ preservation with prompt function and the inability to determine intrarenal perfusion pressure during preservation, thereby missing an important parameter of graft viability.

A Randomized 2x2 Factorial Clinical Trial of Renal Transplantation: Steroid-Free Maintenance Immunosuppression with Calcineurin Inhibitor Withdrawal after Six Months Associates with Improved Renal Function and Reduced Chronic Histopathology

PubMed Central

Stevens, R. Brian; Foster, Kirk W.; Miles, Clifford D.; Kalil, Andre C.; Florescu, Diana F.; Sandoz, John P.; Rigley, Theodore H.; Malik, Tamer; Wrenshall, Lucile E.

2015-01-01

Introduction The two most significant impediments to renal allograft survival are rejection and the direct nephrotoxicity of the immunosuppressant drugs required to prevent it. Calcineurin inhibitors (CNI), a mainstay of most immunosuppression regimens, are particularly nephrotoxic. Until less toxic antirejection agents become available, the only option is to optimize our use of those at hand. Aim To determine whether intensive rabbit anti-thymocyte globulin (rATG) induction followed by CNI withdrawal would individually or combined improve graft function and reduce graft chronic histopathology–surrogates for graft and, therefore, patient survival. As previously reported, a single large rATG dose over 24 hours was well-tolerated and associated with better renal function, fewer infections, and improved patient survival. Here we report testing whether complete CNI discontinuation would improve renal function and decrease graft pathology. Methods Between April 20, 2004 and 4-14-2009 we conducted a prospective, randomized, non-blinded renal transplantation trial of two rATG dosing protocols (single dose, 6 mg/kg vs. divided doses, 1.5 mg/kg every other day x 4; target enrollment = 180). Subsequent maintenance immunosuppression consisted of tacrolimus, a CNI, and sirolimus, a mammalian target of rapamycin inhibitor. We report here the outcome of converting patients after six months either to minimized tacrolimus/sirolimus or mycophenolate mofetil/sirolimus. Primary endpoints were graft function and chronic histopathology from protocol kidney biopsies at 12 and 24 months Results CNI withdrawal (on-treatment analysis) associated with better graft function (p <0.001) and lower chronic histopathology composite scores in protocol biopsies at 12 (p = 0.003) and 24 (p = 0.013) months, without affecting patient (p = 0.81) or graft (p = 0.93) survival, or rejection rate (p = 0.17). Conclusion CNI (tacrolimus) withdrawal at six months may provide a strategy for decreased nephrotoxicity and improved long-term function in steroid-free low immunological risk renal transplant patients. Trial Registration ClinicalTrials.gov NCT00556933 PMID:26465152

Study on plasma pre-functionalized PVC film grafted with TiO2/PVP to improve blood compatible and antibacterial properties

NASA Astrophysics Data System (ADS)

Suganya, Arjunan; Shanmugavelayutham, Gurusamy; Serra Rodríguez, Carmen

2017-04-01

Research into the design of new biopolymers/polymer functionalized with nanoparticles is of tremendous interest to the medical sector, particularly with regard to blood-contacting devices. In this present study, a steady blood compatible and active antibacterial coating was fabricated by the grafting of titanium dioxide (TiO2)/polyvinylpyyrolidone (PVP) onto a polyvinyl chloride (PVC) film surface via the direct-current glow discharge plasma method. To enhance the chemical interaction between TiO2/PVP and PVC, the surfaces of the PVC films were functionalized by different plasmas (air, argon, and oxygen) before coating. In this study, the plasma parameters were varied, such as treatment time of about 5-20 min for a constant power of 100 W, potential 300 V, and a constant gas pressure of 2 Pa for air, argon, and oxygen gas environment. Then, the different plasma treatments on the PVC films, TiO2/PVP were grafted using a simple dip-coating method. In addition, the TiO2/PVP-grafted PVC films were characterized by contact angle, attenuated total reflectance Fourier transform infrared spectroscopy, field-emission scanning electron microscope, and x-ray photo electron spectroscopy. Importantly, TiO2/PVP is grafted onto the PVC surface due to the plasma-based retained functionality and demonstrates adhesive efficiency, which was observed by XPS. The bio-stability of the TiO2/PVP-modified PVC film was evaluated by in vitro platelet activation analysis and protein adsorption analysis. Then, the antibacterial properties were evaluated by the agar diffusion method against Escherichia coli. The result reveals that the grafting of TiO2/PVP was slightly higher for the 15 min oxygen plasma-functionalized PVC, which significantly decreases the platelet adhesion and protein adsorption. Moreover, the antibacterial properties of the 15 min oxygen plasma-functionalized PVC with TiO2/PVP-grafted film is also greatly improved compared with an air- and argon-functionalized surface. Our present study demonstrates that the plasma treatment is a beneficial and eco-friendly method to achieve higher hydrophilicity. Furthermore, our results indicated that the plasma-modified PVC exhibits appropriate anti-fouling performance.

Impact of low-level BK polyomavirus viremia on intermediate-term renal allograft function.

PubMed

Korth, Johannes; Widera, Marek; Dolff, Sebastian; Guberina, Hana; Bienholz, Anja; Brinkhoff, Alexandra; Anastasiou, Olympia Evdoxia; Kribben, Andreas; Dittmer, Ulf; Verheyen, Jens; Wilde, Benjamin; Witzke, Oliver

2018-02-01

BK polyomavirus (BKPyV)-associated nephropathy (PyVAN) is a significant cause of premature renal transplant failure. High-level BKPyV viremia is predictive for PyVAN; however, low-level BKPyV viremia does not necessarily exclude the presence of PyVAN. As data are limited regarding whether or not low-level BKPyV viremia has an effect on intermediate-term graft outcome, this study analyzes the impact of low-level BKPyV viremia on intermediate-term graft function and outcome compared with high-level viremia and non-viremic patients. All renal transplant patients received follow-up examinations at the Department of Nephrology, University Hospital Essen. Patients were screened for BKPyV viremia and stratified into three groups according to their maximum BKPyV load in serum (low-level viremia, high-level viremia, and no viremia). In 142 of 213 (67%) patients, BKPyV was never detected in serum; 42 of 213 (20%) patients were found positive for low-level viremia (≤10 4 copies/mL); and 29 of 213 (13%) patients showed high-level viremia (>10 4 copies/mL). No significant differences regarding transplant function and graft failure were observed between patients without BKPyV viremia (delta estimated glomerular filtration rate [eGFR] +0.1 mL/min [month 1 vs last visit at month 44]) and patients with low-level BKPyV viremia (delta eGFR -1.7 mL/min). In patients with high-level viremia, transplant function was significantly restricted (delta eGFR -6.5 mL/min) compared with low-level viremia until the last visit at 44 ± 9.7 months after transplantation. Although the graft function and graft loss were worse in the high-level viremia group compared with no viremia (eGFR 37 vs 45 mL/min), the difference was not significant. High-level viremia was associated with impaired graft function. In contrast, low-level BKPyV viremia had no significant impact on intermediate-term graft function. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Plasmon-mediated chemical surface functionalization at the nanoscale

NASA Astrophysics Data System (ADS)

Nguyen, Mai; Lamouri, Aazdine; Salameh, Chrystelle; Lévi, Georges; Grand, Johan; Boubekeur-Lecaque, Leïla; Mangeney, Claire; Félidj, Nordin

2016-04-01

Controlling the surface grafting of species at the nanoscale remains a major challenge, likely to generate many opportunities in materials science. In this work, we propose an original strategy for chemical surface functionalization at the nanoscale, taking advantage of localized surface plasmon (LSP) excitation. The surface functionalization is demonstrated through aryl film grafting (derived from a diazonium salt), covalently bonded at the surface of gold lithographic nanostripes. The aryl film is specifically grafted in areas of maximum near field enhancement, as confirmed by numerical calculation based on the discrete dipole approximation method. The energy of the incident light and the LSP wavelength are shown to be crucial parameters to monitor the aryl film thickness of up to ~30 nm. This robust and versatile strategy opens up exciting prospects for the nanoscale confinement of functional layers on surfaces, which should be particularly interesting for molecular sensing or nanooptics.Controlling the surface grafting of species at the nanoscale remains a major challenge, likely to generate many opportunities in materials science. In this work, we propose an original strategy for chemical surface functionalization at the nanoscale, taking advantage of localized surface plasmon (LSP) excitation. The surface functionalization is demonstrated through aryl film grafting (derived from a diazonium salt), covalently bonded at the surface of gold lithographic nanostripes. The aryl film is specifically grafted in areas of maximum near field enhancement, as confirmed by numerical calculation based on the discrete dipole approximation method. The energy of the incident light and the LSP wavelength are shown to be crucial parameters to monitor the aryl film thickness of up to ~30 nm. This robust and versatile strategy opens up exciting prospects for the nanoscale confinement of functional layers on surfaces, which should be particularly interesting for molecular sensing or nanooptics. Electronic supplementary information (ESI) available: Additional figures are displayed (from Fig. SI1-SI6) to illustrate the content of the paper, including the proposed mechanisms of diazonium-derived aryl film grafting, the AFM measurements of the aryl film thickness and the calculation by the DDA method. See DOI: 10.1039/C6NR00744A

Grafting methyl acrylic onto carbon fiber via Diels-Alder reaction for excellent mechanical and tribological properties of phenolic composites

NASA Astrophysics Data System (ADS)

Fei, Jie; Duan, Xiao; Luo, Lan; Zhang, Chao; Qi, Ying; Li, Hejun; Feng, Yongqiang; Huang, Jianfeng

2018-03-01

Carbon fibers (CFs) were grafted with methyl acrylic via Diels-Alder reaction at the different oil bath temperature effectively creating a carboxyl functionalized surface. The effect of grafting temperature on the surface morphology and functional groups of carbon fibers were investigated by FTIR, Raman spectroscopy, XPS and SEM respectively. The results showed that the optimal grafting temperature was 80 °C, and the relative surface coverage by carboxylic acid groups increased from an initial 5.16% up to 19.30% significantly improved the chemical activity without damaging the skin and core region of the carbon fibers. Mechanical property tests indicated that the shear and tensile strength of the sample with the grafting temperature of 80 °C (CFRP-3) increased obviously by 90.3% and 78.7%, respectively, compared with the pristine carbon fibers reinforced composite. Further, the sample CFRP-3 exhibited higher and more stable friction coefficient and improved wear resistance, while the wear rate decreased 52.7%, from 10.8 × 10-6 to 5.1 × 10-6 mm3/N m. The present work shows that grafting methyl acrylic via Diels-Alder reaction could be a highly efficient and facile method to functionalize carbon fibers for advanced composites.

Diversity of gut microflora is required for the generation of B cell with regulatory properties in a skin graft model

PubMed Central

Alhabbab, R.; Blair, P.; Elgueta, R.; Stolarczyk, E.; Marks, E.; Becker, P. D.; Ratnasothy, K.; Smyth, L.; Safinia, N.; Sharif-Paghaleh, E.; O’Connell, S.; Noelle, R. J.; Lord, G. M.; Howard, J. K.; Spencer, J.; Lechler, R. I.; Lombardi, G.

2015-01-01

B cells have been reported to promote graft rejection through alloantibody production. However, there is growing evidence that B cells can contribute to the maintenance of tolerance. Here, we used a mouse model of MHC-class I mismatched skin transplantation to investigate the contribution of B cells to graft survival. We demonstrate that adoptive transfer of B cells prolongs skin graft survival but only when the B cells were isolated from mice housed in low sterility “conventional” (CV) facilities and not from mice housed in pathogen free facilities (SPF). However, prolongation of skin graft survival was lost when B cells were isolated from IL-10 deficient mice housed in CV facilities. The suppressive function of B cells isolated from mice housed in CV facilities correlated with an anti-inflammatory environment and with the presence of a different gut microflora compared to mice maintained in SPF facilities. Treatment of mice in the CV facility with antibiotics abrogated the regulatory capacity of B cells. Finally, we identified transitional B cells isolated from CV facilities as possessing the regulatory function. These findings demonstrate that B cells, and in particular transitional B cells, can promote prolongation of graft survival, a function dependent on licensing by gut microflora. PMID:26109230

Clinical Experience and Best Practices Using Epidermal Skin Grafts on Wounds.

PubMed

Kirsner, Robert S; Bernstein, Brent; Bhatia, Animesh; Lantis, John; Le, Lam; Lincoln, Katherine; Liu, Paul; Rodgers, Lee; Shaw, Mark; Young, David

2015-11-01

Over the years, autologous skin grafting has been used extensively to achieve wound closure, optimize a functional scar, and improve aesthetic outcomes for the patient. Although a vast majority of the literature is on the use of full-thickness and split-thickness skin grafts, epidermal skin grafts (ESGs) have emerged as a viable option in the reconstructive ladder when only the epidermal layer is needed. These grafts are distinct from other types of autologous skin grafts in that they can be harvested without anesthesia and leave minimal or no scarring at the donor site. In order to explore the use of ESGs in the continuum of primary wound closure, a multidisciplinary expert panel convened in October 2014, in Las Vegas, NV, to review the scientific basis and clinical uses of epidermal grafting. This publication provides an overview of epidermal grafting, recommendations for graft application, and potential roles for its use in wound care and closure.

Synaptic inputs from stroke-injured brain to grafted human stem cell-derived neurons activated by sensory stimuli.

PubMed

Tornero, Daniel; Tsupykov, Oleg; Granmo, Marcus; Rodriguez, Cristina; Grønning-Hansen, Marita; Thelin, Jonas; Smozhanik, Ekaterina; Laterza, Cecilia; Wattananit, Somsak; Ge, Ruimin; Tatarishvili, Jemal; Grealish, Shane; Brüstle, Oliver; Skibo, Galina; Parmar, Malin; Schouenborg, Jens; Lindvall, Olle; Kokaia, Zaal

2017-03-01

Transplanted neurons derived from stem cells have been proposed to improve function in animal models of human disease by various mechanisms such as neuronal replacement. However, whether the grafted neurons receive functional synaptic inputs from the recipient's brain and integrate into host neural circuitry is unknown. Here we studied the synaptic inputs from the host brain to grafted cortical neurons derived from human induced pluripotent stem cells after transplantation into stroke-injured rat cerebral cortex. Using the rabies virus-based trans-synaptic tracing method and immunoelectron microscopy, we demonstrate that the grafted neurons receive direct synaptic inputs from neurons in different host brain areas located in a pattern similar to that of neurons projecting to the corresponding endogenous cortical neurons in the intact brain. Electrophysiological in vivo recordings from the cortical implants show that physiological sensory stimuli, i.e. cutaneous stimulation of nose and paw, can activate or inhibit spontaneous activity in grafted neurons, indicating that at least some of the afferent inputs are functional. In agreement, we find using patch-clamp recordings that a portion of grafted neurons respond to photostimulation of virally transfected, channelrhodopsin-2-expressing thalamo-cortical axons in acute brain slices. The present study demonstrates, for the first time, that the host brain regulates the activity of grafted neurons, providing strong evidence that transplanted human induced pluripotent stem cell-derived cortical neurons can become incorporated into injured cortical circuitry. Our findings support the idea that these neurons could contribute to functional recovery in stroke and other conditions causing neuronal loss in cerebral cortex. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Early and late recipient graft function and donor outcome after laparoscopic vs open adult live donor nephrectomy for pediatric renal transplantation.

PubMed

Troppmann, Christoph; Pierce, Jonathan L; Wiesmann, Kevin M; Butani, Lavjay; Makker, Sudesh P; McVicar, John P; Wolfe, Bruce M; Perez, Richard V

2002-08-01

Laparoscopically procured live donor kidney grafts are increasingly transplanted into pediatric recipients. The safety and efficacy of this changed surgical practice are unknown. Outcomes of laparoscopic vs open donor grafts in recipients 18 years and younger are equivalent. Retrospective review at an academic tertiary care referral center. Eleven consecutive pediatric recipients of laparoscopically procured kidneys between April 1, 1997, and December 31, 2001, were pair matched for age with 11 recipients of openly procured kidneys between December 1, 1991, and March 31, 1997; the 22 adult donors were also studied. Recipients: surgical complications, graft function and survival. Donors: perioperative morbidity and length of hospital stay. Twenty (91%) of 22 kidneys were donated by a parent of the recipient. In recipients of laparoscopically procured grafts, we observed significantly lower creatinine clearances and higher creatinine levels on days 1, 4, and 6, but by 1 month, graft function was similar in both groups. No significant differences in surgical complications, delayed function, acute and chronic rejection, and graft survival rates were found. No laparoscopic or open donor required blood transfusion, reoperation, or hospital readmission. One laparoscopic donor (9%) was converted to open nephrectomy. For laparoscopic vs open donors, median operative time was longer (difference, 67 min; P =.08), but median postoperative length of stay was significantly shorter (3 vs 5 days; P =.02). Laparoscopic live donor nephrectomy has no adverse impact on pediatric recipient outcomes. For donors, the laparoscopic operation is safe and the hospital stay is shortened. These results support the continued use of laparoscopically procured live donor kidneys in pediatric renal transplantation.

Preservation of anal function after total excision of the anal mucosa for Bowen's disease.

PubMed

Reynolds, V H; Madden, J J; Franklin, J D; Burnett, L S; Jones, H W; Lynch, J B

1984-05-01

Six women with Bowen's disease of the anogenital area were treated by total excision of the anal mucosa, perianal skin and, in some cases, partial vulvectomy. Two patients had foci of microinvasive squamous carcinoma. Adequate tumor margins were determined by frozen sections. The resulting mucosal and cutaneous defects were grafted with medium split-thickness skin grafts applied to the anal canal and sutured circumferentially to the rectal mucosa. Grafts were held in place by a finger cot inserted in the anal canal and stuffed with cotton balls. Patients were constipated five or six days with codeine. The skin grafts healed per primam. One additional patient was similarly treated for a chronic herpetic ulceration of the anus and healed. Contrary to dire predictions, all patients were able to distinguish between gaseous and solid rectal contents and sphincter function was preserved. In one patient, Bowen's disease has recurred in the grafted perianal skin.

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.

Bypass grafting to the anterior tibial artery.

PubMed

Armour, R H

1976-01-01

Four patients with severe ischaemia of a leg due to atherosclerotic occlusion of the tibial and peroneal arteries had reversed long saphenous vein grafts to the patent lower part of the anterior tibial artery. Two of these grafts continue to function 19 and 24 months after operation respectively. One graft failed on the fifth postoperative day and another occluded 4 months after operation. The literature on femorotibial grafting has been reviewed. The early failure rate of distal grafting is higher than in the case of femoropopliteal bypass, but a number of otherwise doomed limbs can be salvaged. Contrary to widely held views, grafting to the anterior tibial artery appears to give results comparable to those obtained when the lower anastomosis is made to the posterior tibial artery.

Comparison of the long-term outcomes of kidney transplantation: USA versus Spain

PubMed Central

Ojo, Akinlolu O.; Morales, José María; González-Molina, Miguel; Steffick, Diane E.; Luan, Fu L.; Merion, Robert M.; Ojo, Tammy; Moreso, Francesc; Arias, Manuel; Campistol, Josep María; Hernandez, Domingo; Serón, Daniel

2013-01-01

Background The long-term outcomes of kidney transplantation are suboptimal because many patients lose their allografts or experience premature death. Cross-country comparisons of long-term outcomes of kidney transplantation may provide insight into factors contributing to premature graft failure and death. We evaluated the rates of late graft failure and death among US and Spanish kidney recipients. Methods This is a cohort study of US (n = 9609) and Spanish (n = 3808) patients who received a deceased donor kidney transplant in 1990, 1994, 1998 or 2002 and had a functioning allograft 1 year after transplantation with follow-up through September 2006. Ten-year overall and death-censored graft survival and 10-year overall recipient survival and death with graft function (DWGF) were estimated with multivariate Cox models. Results Among recipients alive with graft function 1 year after transplant, the 10-year graft survival was 71.3% for Spanish and 53.4% for US recipients (P < 0.001). The 10-year, death-censored graft survival was 75.6 and 76.0% for Spanish and US recipients, respectively (P = 0.73). The 10-year recipient survival was 86.2% for Spanish and 67.4% for US recipients (P < 0.001). In recipients with diabetes as the cause of ESRD, the adjusted DWGF rates at 10 years were 23.9 and 53.8 per 1000 person-years for Spanish and US recipients, respectively (P < 0.001). Among recipients whose cause of ESRD was not diabetes mellitus, the adjusted 10-year DWGF rates were 11.0 and 25.4 per 1000 person-years for Spanish and US recipients, respectively. Conclusions US kidney transplant recipients had more than twice the long-term hazard of DWGF compared with Spanish kidney transplant recipients and similar levels of death-censored graft function. Pre-transplant medical care, comorbidities, such as cardiovascular disease, and their management in each country's health system are possible explanations for the differences between the two countries. PMID:22759384

Comparison of the long-term outcomes of kidney transplantation: USA versus Spain.

PubMed

Ojo, Akinlolu O; Morales, José María; González-Molina, Miguel; Steffick, Diane E; Luan, Fu L; Merion, Robert M; Ojo, Tammy; Moreso, Francesc; Arias, Manuel; Campistol, Josep María; Hernandez, Domingo; Serón, Daniel

2013-01-01

The long-term outcomes of kidney transplantation are suboptimal because many patients lose their allografts or experience premature death. Cross-country comparisons of long-term outcomes of kidney transplantation may provide insight into factors contributing to premature graft failure and death. We evaluated the rates of late graft failure and death among US and Spanish kidney recipients. This is a cohort study of US (n = 9609) and Spanish (n = 3808) patients who received a deceased donor kidney transplant in 1990, 1994, 1998 or 2002 and had a functioning allograft 1 year after transplantation with follow-up through September 2006. Ten-year overall and death-censored graft survival and 10-year overall recipient survival and death with graft function (DWGF) were estimated with multivariate Cox models. Among recipients alive with graft function 1 year after transplant, the 10-year graft survival was 71.3% for Spanish and 53.4% for US recipients (P < 0.001). The 10-year, death-censored graft survival was 75.6 and 76.0% for Spanish and US recipients, respectively (P = 0.73). The 10-year recipient survival was 86.2% for Spanish and 67.4% for US recipients (P < 0.001). In recipients with diabetes as the cause of ESRD, the adjusted DWGF rates at 10 years were 23.9 and 53.8 per 1000 person-years for Spanish and US recipients, respectively (P < 0.001). Among recipients whose cause of ESRD was not diabetes mellitus, the adjusted 10-year DWGF rates were 11.0 and 25.4 per 1000 person-years for Spanish and US recipients, respectively. US kidney transplant recipients had more than twice the long-term hazard of DWGF compared with Spanish kidney transplant recipients and similar levels of death-censored graft function. Pre-transplant medical care, comorbidities, such as cardiovascular disease, and their management in each country's health system are possible explanations for the differences between the two countries.

Outcomes of rotator cuff augmentation surgery with autologous fascia lata.

PubMed

Rosales-Varo, A P; García-Espona, M A; Roda-Murillo, O

To evaluate whether augmentation grafts using autologous fascia lata improve functional results for rotator cuff repairs and reduce the retear rate compared to those without augmentation. This is a prospective evaluation comprising 20 patients with a complete symptomatic rotator cuff tear. The operations were carried out from a superior approach performing a total cuff repair, for 10 patients we used a suture augmented with an autologous graft taken from their own fascia lata while unaugmented sutures were used for the other 10 patients. The follow-up period lasted for one year post-intervention. We measured variables for tear type, functionality and pain, both baseline and at 6 and 12-month follow ups. We evaluated retear incidence in each group as well as each group's pain and functionality response. The improved pain levels in the non-graft group evolved gradually over time. Conversely, in the group with the augmentation grafts, average Constant-Murley shoulder outcome scores at six months were already above 10 and were maintained at 12 months. One retear occurred in the graft group and 2 in the group without grafts, thus presenting no significant differences. There were no significant changes in pain and function values at the one year follow up in either group. Our preliminary results regarding rotator cuff augmentation surgery with autologous fascia lata showed a significant improvement in pain levels after 6 months compared to the patients with no augmentation, who required 12 months to reach the same values. After a year of follow up, there were no differences between the mean Constant and pain scores in either intervention group The number of retears in the non-graft group was greater than that in the group with grafts although the difference was not significant. Copyright © 2018 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Liver grafts from selected older donors do not have significantly more ischaemia reperfusion injury

PubMed Central

Martins, Paulo N; Chang, Sue; Mahadevapa, Basant; Martins, Ann-Britt; Sheiner, Patricia

2011-01-01

Background There is a general concern that aged organs are more susceptible to ischaemia. In the light of recent proposals to change the liver allocation system by expanding regional sharing, it is feared that increased cold ischaemia time of grafts from older donors may reduce graft survival. The aim of this study was to correlate donor age and the patterns of ischaemia reperfusion injury and synthetic function early after liver transplantation. Methods We performed a retrospective study of first transplants using a single-centre electronic database. Patterns of liver injury (based on transaminases and post-reperfusion biopsy), synthetic function (international normalized ratio [INR]), and graft and patient survival in recipients receiving liver grafts from donors aged ≥65 years (group 1, n= 50) were compared with equivalent patterns in a matched cohort of recipients transplanted with grafts from donors aged <65 years (group 2, n= 50). Results There was no significant difference in transaminase levels from day 0 to day 6 after transplantation. When groups 1 and 2 were subdivided into two subgroups based on the duration of graft cold ischaemia time (<8 h and ≥8 h), there was no statistical difference in transaminase levels during the first 7 days. There were two cases (4%) of primary non-function in group 1 and one (2%) in group 2. Initial poor function did not differ significantly between the groups (26% vs. 24%; P= 0.81). In addition, there was no difference in histological changes in post-reperfusion biopsies (21% vs. 34%; P= 0.078) and rate of acute rejection episodes in the first year (30% vs. 32%; P= 0.99). There was no significant difference between groups 1 and 2 in 1-year patient and graft survivals (78% vs. 90% [P= 0.17]; 88% vs. 94% [P= 0.48], respectively). Conclusions Judiciously selected livers from aged donors are not associated with major increased susceptibility to ischaemia reperfusion injury. PMID:21309940

Atom-scale covalent electrochemical modification of single-layer graphene on SiC substrates by diaryliodonium salts

DOE PAGES

Gearba, Raluca I.; Mueller, Kory M.; Veneman, Peter A.; ...

2015-05-09

Owing to its high conductivity, graphene holds promise as an electrode for energy devices such as batteries and photovoltaics. However, to this end, the work function and doping levels in graphene need to be precisely tuned. One promising route for modifying graphene’s electronic properties is via controlled covalent electrochemical grafting of molecules. We show that by employing diaryliodonium salts instead of the commonly used diazonium salts, spontaneous functionalization is avoided. This then allows for precise tuning of the grafting density. Moreover, by employing bis(4-nitrophenyl)iodonium(III) tetrafluoroborate (DNP) salt calibration curves, the surface functionalization density (coverage) of glassy carbon was controlled usingmore » cyclic voltammetry in varying salt concentrations. These electro-grafting conditions and calibration curves translated directly over to modifying single layer epitaxial graphene substrates (grown on insulating 6H-SiC (0 0 0 1)). In addition to quantifying the functionalization densities using electrochemical methods, samples with low grafting densities were characterized by low-temperature scanning tunneling microscopy (LT-STM). We show that the use of buffer-layer free graphene substrates is required for clear observation of the nitrophenyl modifications. Furthermore, atomically-resolved STM images of single site modifications were obtained, showing no preferential grafting at defect sites or SiC step edges as supposed previously in the literature. Most of the grafts exhibit threefold symmetry, but occasional extended modifications (larger than 4 nm) were observed as well.« less

Circumferentially aligned fibers guided functional neoartery regeneration in vivo.

PubMed

Zhu, Meifeng; Wang, Zhihong; Zhang, Jiamin; Wang, Lina; Yang, Xiaohu; Chen, Jingrui; Fan, Guanwei; Ji, Shenglu; Xing, Cheng; Wang, Kai; Zhao, Qiang; Zhu, Yan; Kong, Deling; Wang, Lianyong

2015-08-01

An ideal vascular graft should have the ability to guide the regeneration of neovessels with structure and function similar to those of the native blood vessels. Regeneration of vascular smooth muscle cells (VSMCs) with circumferential orientation within the grafts is crucial for functional vascular reconstruction in vivo. To date, designing and fabricating a vascular graft with well-defined geometric cues to facilitate simultaneously VSMCs infiltration and their circumferential alignment remains a great challenge and scarcely reported in vivo. Thus, we have designed a bi-layered vascular graft, of which the internal layer is composed of circumferentially aligned microfibers prepared by wet-spinning and an external layer composed of random nanofibers prepared by electrospinning. While the internal circumferentially aligned microfibers provide topographic guidance for in vivo regeneration of circumferentially aligned VSMCs, the external random nanofibers can offer enhanced mechanical property and prevent bleeding during and after graft implantation. VSMCs infiltration and alignment within the scaffold was then evaluated in vitro and in vivo. Our results demonstrated that the circumferentially oriented VSMCs and longitudinally aligned ECs were successfully regenerated in vivo after the bi-layered vascular grafts were implanted in rat abdominal aorta. No formation of thrombosis or intimal hyperplasia was observed up to 3 month post implantation. Further, the regenerated neoartery exhibited contraction and relaxation property in response to vasoactive agents. This new strategy may bring cell-free small diameter vascular grafts closer to clinical application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Aqueous or solvent based surface modification: The influence of the combination solvent - organic functional group on the surface characteristics of titanium dioxide grafted with organophosphonic acids

NASA Astrophysics Data System (ADS)

Roevens, Annelore; Van Dijck, Jeroen G.; Geldof, Davy; Blockhuys, Frank; Prelot, Benedicte; Zajac, Jerzy; Meynen, Vera

2017-09-01

To alter the versatility of interactions at its surface, TiO2 is modified with organophosphonic acids (PA). A thorough understanding of the role of all synthesis conditions is necessary to achieve controlled functionalization. This study reports on the effect of using water, toluene and their mixtures when performing the modification of TiO2 with PA. Sorption and calorimetry measurements of surface interactions with various probing species clearly indicate that, by grafting PA in water, clear differences appear in the distribution of organic groups on the surface. Also the functional group of the PA determines the impact of using water as solvent. Modification in toluene results in a higher modification degree for propylphosphonic acid (3PA), as the solvent-solute interaction may hinder the grafting with phenylphosphonic acid (PhPA) in toluene. Water is preferred as solvent for PhPA modification as stabilizing π-OH interactions enhance surface grafting overcoming the competitive interaction of water at the surface as observed with 3PA. By using water in toluene mixtures for the functionalization of TiO2 with 3PA, the degree of functionalization is higher than when only water or toluene is used. Furthermore, adding small amounts of water leads to the formation of titanium propylphosphonates, next to surface grafting.

Assessment of nerve regeneration across nerve allografts treated with tacrolimus.

PubMed

Haisheng, Han; Songjie, Zuo; Xin, Li

2008-01-01

Although regeneration of nerve allotransplant is a major concern in the clinic, there have been few papers quantitatively assessing functional recovery of animals' nerve allografts in the long term. In this study, functional recovery, histopathological study, and immunohistochemistry changes of rat nerve allograft with FK506 were investigated up to 12 weeks without slaughtering. C57 and SD rats were used for transplantation. The donor's nerve was sliced and transplanted into the recipient. The sciatic nerve was epineurally sutured with 10-0 nylon. In total, 30 models of transplantation were performed and divided into 3 groups that were either treated with FK506 or not. Functional recovery of the grafted nerve was serially assessed by the pin click test, walking track analysis and electrophysiological evaluations. A histopathological study and immunohistochemistry study were done in the all of the models. Nerve allografts treated with FK506 have no immune rejection through 12 weeks. Sensibility had similarly improved in both isografts and allografts. There has been no difference in each graft. Walk track analysis demonstrates significant recovery of motor function of the nerve graft. No histological results of difference were found up to 12 weeks in each graft. In the rodent nerve graft model, FK506 prevented nerve allograft rejection across a major histocompatibility barrier. Sensory recovery seems to be superior to motor function. Nerve isograft and allograft treated with FK506 have no significant difference in function recovery, histopathological result, and immunohistochemistry changes.

[Aortic reconstruction with graft materials resistant to bacterial infections].

PubMed

Hassen-Khodja, Réda; Sadaghianloo, Nirvana; Jean-Baptiste, Élixène

2013-01-01

Synthetic graft infection is a rare but extremely serious complication of aortic reconstruction procedures, with morbidity-mortality rates as high as 60 %. Some of the proteins (albumin, gelatin, collagen) used to coat polyester graft materials can establish ionic bonds with antibiotics or can capture antiseptics such as triclosan or ionic silver in their matrices. These active substances are then released from the graft, at varying rates, during the coating degradation that takes place during the weeks following polyester graft implantation in living tissues. Rifampin-bonded prostheses have proved effective against S. aureus and S. epidermidis in several canine models of synthetic aortic graft infection. Rifampin-bonded grafts have also been used successfully in patients with synthetic aortic graft infection by low-virulence bacteria. However, their effectiveness may be limited by the diverse and changing ecology of synthetic aortic graft infections, with an increasing prevalence of multidrug-resistant bacteria and polymicrobial infections. These include species that are naturally, or are likely to become, resistant to rifampin. We evaluated silver-ion-bonded prostheses in this setting but observed a disappointingly high mid-term rate of recurrent infections. Over the past few years we have been involved in the development of polyester vascular prostheses functionalized with a hydroxypropyl-β-cyclodextrin polymeric matrix that can capture and elute several therapeutic agents. The results are promising, as these prostheses enable the sustained release of various antibiotics in amounts several times their minimum inhibitory concentrations. This provides a unique opportunity to functionalize materials for aortic graft reconstruction, based on epidemiological data or individual bacteriological findings.

Sural nerve grafting in robotic laparoscopic radical prostatectomy: interim report.

PubMed

Mikhail, Albert A; Song, David H; Zorn, Kevin C; Orvieto, Marcelo A; Taxy, Jerome B; Lin, Shang P; Mendiola, Frederick P; Shalhav, Arieh L; Zagaja, Gregory P

2007-12-01

Sural nerve grafting for patients undergoing prostatectomy has been previously reported using open and minimally invasive methods. We report our experience with sural nerve grafting during robot-assisted laparoscopic radical prostatectomy (RLRP). Patients with preoperative potency and a minimum of 6 months follow-up were included in this prospective review. A total of 333 patients were identified between February 2003 and January 2006 who met these criteria including 22 of the 25 patients who underwent sural nerve grafting. Patients were divided into 5 groups to compare unilateral and bilateral sural nerve cohorts with non-nerve-sparing and unilateral and bilateral nerve-sparing groups. Patients were followed prospectively using health-related quality-of-life questionnaires. Twenty-two patients underwent sural nerve grafting that included three bilateral grafts. Mean follow-up was 14 months. There was no statistical difference in patients' ages, body mass index, preoperative prostate-specific antigen level, blood loss, complications, and positive margin rate. Operative time was statistically longer for both sural graft cohorts when compared with unilateral (without graft) and bilateral nerve sparing cohorts. No significant differences in subjective or objective sexual function, sexual bother, or urinary function were seen with 6 and 12 months follow-up, possibly related to smaller sural cohorts. Graft-related complications include leg pain in one patient. Sural nerve grafting during RLRP is technically feasible and safe and offers improved dexterity and visualization deep within the pelvis. However, a larger randomized cohort of patients will be required to validate any improved benefits afforded by the robot system.

Preserved hyperaemic response in (distal) string sign left internal mammary artery grafts.

PubMed

Hartman, Joost; Kelder, Hans; Ackerstaff, Rob; van Swieten, Henry; Vermeulen, Freddy; Bogers, Ad

2007-02-01

To correlate supraclavicular ultrasonography at rest and in hyperaemic response with angiographically patent and (distal) 'string sign' left internal mammary artery (LIMA) to left anterior descending (LAD) area grafts. Fifty-three patients with LIMA to LAD area grafting were prospectively entered in a follow-up study. Arteriography (native and LIMA) was performed at 1.4+/-0.8 years postoperatively and ultrasonography was performed at rest, in hyperaemic response and 2min after hyperaemic response at 1.8+/-0.8 years postoperatively and was compared to arteriography. Ultrasonographic parameters analysed were systolic and diastolic peak velocity, systolic and diastolic velocity integral, diastolic/systolic peak velocity ratio and diastolic/total velocity integral ratio. One patient was excluded because obesity hampered ultrasonography. Arteriography demonstrated functional grafts in 43 patients (group I), sequential distal 'string sign grafts' in 4 patients (group II) and total 'string sign grafts' in 5 patients (group III). Between the groups all ultrasonographic velocities showed a significant linear relation (p

Use of autologous grafts in the treatment of acquired penile curvature: An experience of 33 cases

PubMed Central

Khawaja, Abdul Rouf; Dar, Tanveer Iqbal; Zahur, Suhael; Tariq, Sheikh; Hamid, Arf; Wani, M. S.; Wazir, B. S.; Iqbal, Arsheed

2016-01-01

Aim: The objective was to compare the use of autologous dermal and temporalis fascia grafts in the treatment of acquired penile curvatures. Materials and Methods: It was a prospective observational study of 33 cases, conducted in Sher-i-Kashmir Institute of Medical Sciences, Srinagar from March 2007 to September 2013. All the patients had stable Peyronies disease (PD). Dorsal, dorsolateral and vental curvatures with good preoperative erections were included. PD index with visual analog scales for curvature was used preoperatively. An informed written consent was taken from all the patients with main emphasis on erectile dysfunction. Results: After an average follow up of 2 years, complete straightening of penis was observed in all patients with satisfactory sexual intercourse in 30 patients (90%). Three patients (10%) required frequent use of type 5 phosphodiesterase inhibitors for adequate erections. Overall 91% of patients and partners were satisfied with the procedure and cosmetically donor site was better in temporalis fascia graft site. No rejection of any graft was noted and glans hypoesthesia was noticed in 4 patients (12%). None of the patients required penile prosthesis. Total operative time for harvesting and application of the graft was more in dermal grafts (>3 hrs) than for temporalis fascia graft (2 hrs). Conclusion: Tunical lengthening procedures by autologous free grafts represents a safe and reproducible technique. A good preoperative erectile function is required for tunical lengthening procedure. Temporalis fascia graft is thin, tough membrane and effective graft for PD with good cosmetic and functional results. PMID:27141196

Four decades of the kidney transplantation program at the Institute Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City.

PubMed

Morales-Buenrostro, Luis E; Marino-Vázquez, Lluvia A; Alberú, Josefina

2009-01-01

This is a retrospective study that includes four decades of kidney transplant program at our Institute, with a total of 923 kidney transplants in 872 recipients. In this report, the effect of variables in recipient, donor, and transplant on long-term graft survival was analyzed using the Kaplan Meier method with log-rank test for survival comparisons. Global graft survival at our center-analyzed by censoring for death-with-functioning-graft-for 1, 5 and 10 years was 93%, 83% and 74%, respectively, with median survival of 24.5 years. When analyzed for all-cause graft loss, 1, 5 and 10 year survival was 90%, 76% and 61%, with 12.8-year median survival. Variables associated with lower graft survival censored for death-with-functioning-graft were transplantation in an earlier decade, less histocompatibility, younger kidney transplant recipients, no induction therapy, and double drug initial immunosuppression. After Cox's regression multivariate analysis, the risk factors that remained associated with worse survival were younger recipient, earlier transplant decade, and deceased donor.

Assessment of Functional Rhinoplasty with Spreader Grafting Using Acoustic Rhinomanometry and Validated Outcome Measurements

PubMed Central

Paul, Marek A.; Kamali, Parisa; Chen, Austin D.; Ibrahim, Ahmed M. S.; Wu, Winona; Becherer, Babette E.; Medin, Caroline

2018-01-01

Background: Rhinoplasty is 1 of the most common aesthetic and reconstructive plastic surgical procedures performed within the United States. Yet, data on functional reconstructive open and closed rhinoplasty procedures with or without spreader graft placement are not definitive as only a few studies have examined both validated measurable objective and subjective outcomes of spreader grafting during rhinoplasty. The aim of this study was to utilize previously validated measures to assess objective, functional outcomes in patients who underwent open and closed rhinoplasty with spreader grafting. Methods: We performed a retrospective review of consecutive rhinoplasty patients. Patients with internal nasal valve insufficiency who underwent an open and closed approach rhinoplasty between 2007 and 2016 were studied. The Cottle test and Nasal Obstruction Symptom Evaluation survey was used to assess nasal obstruction. Patient-reported symptoms were recorded. Acoustic rhinometry was performed pre- and postoperatively. Average minimal cross-sectional area of the nose was measured. Results: One hundred seventy-eight patients were reviewed over a period of 8 years. Thirty-eight patients were included in this study. Of those, 30 patients underwent closed rhinoplasty and 8 open rhinoplasty. Mean age was 36.9 ± 18.4 years. The average cross-sectional area in closed and open rhinoplasty patients increased significantly (P = 0.019). There was a functional improvement in all presented cases using the Nasal Obstruction Symptom Evaluation scale evaluation. Conclusions: Closed rhinoplasty with spreader grafting may play a significant role in the treatment of nasal valve collapse. A closed approach rhinoplasty including spreader grafting is a viable option in select cases with objective and validated functional improvement. PMID:29707440

CT-based renal volume and graft function after living-donor kidney transplantation: Is there a volume threshold to avoid?

PubMed

Dias, Jorge; Malheiro, Jorge; Almeida, Manuela; Dias, Leonídio; Silva-Ramos, Miguel; Martins, La Salete; Xambre, Luís; Castro-Henriques, António

2015-05-01

Donated kidney volume influences post-transplant outcomes and graft survival. We evaluated the relationship between living-donor kidney volume and recipient graft function at 12 months post-transplantation, exploring a volume threshold for a suboptimal graft function, and compared two different formulas of volume estimation. A retrospective analysis of 82 pairs of living-donor kidney transplants was conducted. Donor renal volumes were estimated from computerized tomography scans using the ellipsoid formula and the voxel counting technique. Linear and restricted cubic regression spline was used to analyze the association of volume with graft function. Additionally, we determined the correlation between the two volume estimation formulas and established a correction factor for the ellipsoid formula. Renal volume (adjusted to recipient BSA) had the strongest independent effect (B = 1.65 per 10 ml/m(2) increase, p value <0.001) on graft function at 12 months. The eGFR at 12 months was 52.5, 63.6 and 67.6 ml/min/1.73 m(2) for the low, medium and high volume ratio terciles, respectively (p value <0.001). The odds of a GFR <50 ml/min became significantly reduced with volumes above 145 cc/1.73 m(2). A strong positive correlation between the two formulas was identified (R(2) = 0.705), but the optimal correction factor for our cohort was 0.566. In a Caucasian population, higher donor kidney volumes estimated from preoperative CT scans are associated with higher recipient eGFRs at 12 months after live-donor transplantation. Using this criterion, transplant teams can potentially improve selection of living donors if multiple donors are available. However, the need for precise estimation of donor kidney volumes should not be overlooked.

High Risk of Graft Failure in Emerging Adult Heart Transplant Recipients.

PubMed

Foster, B J; Dahhou, M; Zhang, X; Dharnidharka, V; Ng, V; Conway, J

2015-12-01

Emerging adulthood (17-24 years) is a period of high risk for graft failure in kidney transplant. Whether a similar association exists in heart transplant recipients is unknown. We sought to estimate the relative hazards of graft failure at different current ages, compared with patients between 20 and 24 years old. We evaluated 11 473 patients recorded in the Scientific Registry of Transplant Recipients who received a first transplant at <40 years old (1988-2013) and had at least 6 months of graft function. Time-dependent Cox models were used to estimate the association between current age (time-dependent) and failure risk, adjusted for time since transplant and other potential confounders. Failure was defined as death following graft failure or retransplant; observation was censored at death with graft function. There were 2567 failures. Crude age-specific graft failure rates were highest in 21-24 year olds (4.2 per 100 person-years). Compared to individuals with the same time since transplant, 21-24 year olds had significantly higher failure rates than all other age periods except 17-20 years (HR 0.92 [95%CI 0.77, 1.09]) and 25-29 years (0.86 [0.73, 1.03]). Among young first heart transplant recipients, graft failure risks are highest in the period from 17 to 29 years of age. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

Transplantation outcomes in primary hyperoxaluria.

PubMed

Bergstralh, E J; Monico, C G; Lieske, J C; Herges, R M; Langman, C B; Hoppe, B; Milliner, D S

2010-11-01

Optimal transplantation strategies are uncertain in primary hyperoxaluria (PH) due to potential for recurrent oxalosis. Outcomes of different transplantation approaches were compared using life-table methods to determine kidney graft survival among 203 patients in the International Primary Hyperoxaluria Registry. From 1976-2009, 84 kidney alone (K) and combined kidney and liver (K + L) transplants were performed in 58 patients. Among 58 first kidney transplants (32 K, 26 K + L), 1-, 3- and 5-year kidney graft survival was 82%, 68% and 49%. Renal graft loss occurred in 26 first transplants due to oxalosis in ten, chronic allograft nephropathy in six, rejection in five and other causes in five. Delay in PH diagnosis until after transplant favored early graft loss (p = 0.07). K + L had better kidney graft outcomes than K with death-censored graft survival 95% versus 56% at 3 years (p = 0.011). Among 29 year 2000-09 first transplants (24 K + L), 84% were functioning at 3 years compared to 55% of earlier transplants (p = 0.05). At 6.8 years after transplantation, 46 of 58 patients are living (43 with functioning grafts). Outcomes of transplantation in PH have improved over time, with recent K + L transplantation highly successful. Recurrent oxalosis accounted for a minority of kidney graft losses. ©2010 The Authors Journal compilation©2010 The American Society of Transplantation and the American Society of Transplant Surgeons.

The Study of Interpenetration Length between dPS Films and PS-grafted Layers

NASA Astrophysics Data System (ADS)

Lee, Hoyeon; Jo, Seongjun; Hirata, Toyoaki; Yamada, Norifumi L.; Tanaka, Keiji; Ryu, Du Yeol

In polymer thin film system, the type of interfacial interaction is a critical parameter to determining the thermal and physical properties of polymer films. Interestingly, the interfacial energy of grafted substrates with polymer chains is remarkably altered by simply controlling grafting density, which has been referred to as autophobicity. In this study, we investigated the interpenetrating interfaces between deuterated polystyrene (dPS) and grafted substrates with the same chemical identity. PS-grafted substrates were prepared using a grafting-to approach with hydroxyl end-functionalized polystyrene (PSOH) in a dry brush regime, where the brush thickness and grafting density were determined based on the chain length (or molecular weight, Mn) of PSOHs. The interpenetration lengths (ξ) at interfaces between dPS and PS-grafted layers were characterized using neutron reflectivity (NR) measurements (performed at the SOFIA beam-line at J-PARC, Japan). Academic adviser.

Local full-thickness skin graft of the donor arm--a novel technique for the reduction of donor site morbidity in radial forearm free flap.

PubMed

Riecke, B; Assaf, A T; Heiland, M; Al-Dam, A; Gröbe, A; Blessmann, M; Wikner, J

2015-08-01

A novel technique to reduce donor site morbidity after radial forearm free flap (RFFF) harvest, using a local full-thickness skin graft (FTSG), is described. Thirty consecutive patients undergoing RFFF for head and neck reconstruction were enrolled in a prospective study. Donor site defect closure was performed with spindle-shaped FTSGs excised from the wavelike skin incision made for the vascular pedicle. Both the removal site of the FTSG on the volar forearm and the covered RFFF donor site healed uneventfully in 29 cases, with no impairment of function related to the skin graft. No skin graft failure and no exposure, tenting, or adherence of the flexor tendons occurred. All patients expressed satisfaction with postoperative pain, the functional outcome, and cosmetic appearance. Primary donor site defect closure could be achieved in all cases with the use of a local FTSG. This graft can be gained at the access incision for the vascular pedicle, avoids expansion of the incision for a local flap technique, and does not prolong wound healing, and thus reduces both donor site and graft site morbidity of the RFFF. This technique leads to an inconspicuous aesthetic result with no apparent relevant functional deficits and avoids the need for a second donor site. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The Effects of Bio-Lubricating Molecules on Flexor Tendon Reconstruction in A Canine Allograft Model In Vivo

PubMed Central

Zhao, Chunfeng; Wei, Zhuang; Kirk, Ramona L.; Thoreson, Andrew R.; Jay, Gregory D.; Moran, Steven L.; An, Kai-Nan; Amadio, Peter C.

2014-01-01

Background Using allograft is an attractive alternative for flexor tendon reconstruction because of the lack of donor morbidity, and better matching to the intrasynovial environment. The purpose of this study was to use biolubricant molecules to modify the graft surface to decrease adhesions and improve digit function. Methods 28 flexor digitorum profundus (FDP) tendons from the 2nd and 5th digits of 14 dogs were first lacerated and repaired to create a model with repair failure and scar digit for tendon reconstruction. Six weeks after the initial surgery, the tendons were reconstructed with FDP allograft tendons obtained from canine cadavers. One graft tendon in each dog was treated with saline as a control and the other was treated with gelatin, carbodiimide derivatized, hyaluronic acid and lubricin (cd-HA-Lubricin). Six weeks postoperatively, digit function, graft mechanics, and biology were analyzed. Results Allograft tendons treated with cd-HA-Lubricin had decreased adhesions at the proximal tendon/graft repair and within flexor sheath, improved digit function, and increased graft gliding ability. The treatment also reduced the strength at the distal tendon to bone repair, but the distal attachment rupture rate was similar for both graft types. Histology showed that viable cells migrated to the allograft, but these were limited to the tendon surface. Conclusion cd-HA-Lubricin treatment of tendon allograft improves digit functional outcomes after flexor tendon reconstruction. However, delayed bone-tendon healing should be a caution. Furthermore, the cell infiltration into the allograft tendons substance should be a target for future studies, to shorten the allograft self-regeneration period. PMID:24445876

Ex-vivo perfusion machines in kidney transplantation. The significance of the resistivity index.

PubMed

Elec, Florin Ioan; Lucan, Ciprian; Ghervan, Liviu; Munteanu, Valentin; Moga, Silviu; Suciu, Mihai; Enache, Dan; Elec, Alina; Munteanu, Adriana; Barbos, Adrian; Iacob, Gheorghita; Lucan, Mihai

2014-01-01

With a growing shortage of organs for transplantation, finding ways of increasing the donor organ pool remains of utmost importance. Perfusion machines (PM) have been proven to enhance the potential for kidney transplants to function sooner, last longer, giving patients the opportunity for a better life quality. The aim of this study is to evaluate the relation between the resistance index provided by the PM, the postoperative resistance index measured by Doppler ultrasound and the initial graft outcome. Between January 2012-December 2012, clinical data obtained from 82 consecutive renal transplants from brain death donors (BDD) which underwent PM maintenance were analyzed in a transversal study. Prior transplantation we recorded the solution temperature, filtration rate and the resistance index provided by PM. After the surgical intervention, each patient had standard follow-up. Doppler ultrasound resistivity index (RI) was recorded on the first postoperative day. Out of 115 renal transplants, 98 (85.21%) were performed with grafts from BDD. The PM was used for 82 renal grafts. The Doppler resistance index in relation to the resistance index shows a highly statistical correlation by linear regression (R=0.813, p<0.0001). Primary graft function was recorded in 74 patients (90.24%) and it was highly statistically significant correlated with the resistance index measured by PM. Out of 8 patients with primary non-function, 6 patients recovered with normal graft function at one year. The resistivity index recorded by the life-port machine is correlated with the vascular resistivity index measured by Doppler ultrasound and thus it may predicts the primary graft outcome.

Interdigitated electrodes (IDE) using elastomer functionalized multi-walled carbon nanotube (MWNT) nanocomposites for the detection of oil spills

NASA Astrophysics Data System (ADS)

Kim, Tae-Yong; Lee, Hyunseung; Park, Boyeong; Kim, Yangsoo

2018-03-01

IDE using elastomer functionalized MWNT nanocomposites was fabricated and applied for the oil sensor. Two types of nanocomposites (i.e., MWNT-grafting-polyisoprene and Si-MWNT/natural rubber) having elastomer content of ~70 wt% were used as a sensing material of oil sensor and the relative electrical resistance response of the sensor to three different kinds of oils (i.e., gasoline, engine oil and pump oil) was investigated. Among three kinds of oils, the response of MWNT-grafting-polyisoprene nanocomposites IDE sensor to gasoline was the most significant. It showed the maximum relative electrical resistance of 18 within 20 min of dropping of 200 μL gasoline at room temperature for the MWNT-grafting-polyisoprene nanocomposites, which is far superior in sensitivity to the experimental results reported by Ponnamma et al in 2016 [1]. On the other hand, the response of Si-MWNT/natural rubber nanocomposites IDE sensor to gasoline was not appreciable. The elastomer functionalized MWNT nanocomposites prepared by “grafting-from” method, which is MWNT-grafting-polyisoprene in this study, is an excellent candidate material for the detection of oil spills.

UV-Induced [2+2] Grafting-To Reactions for Polymer Modification of Cellulose.

PubMed

Conradi, Matthias; Ramakers, Gijs; Junkers, Thomas

2016-01-01

Benzaldehyde-functional cellulose paper sheets have been synthesized via tosylation of cellulose (Whatman No 5) followed by addition of p-hydroxy benzaldehyde. Via UV-induced Paterno-Büchi [2+2] cycloaddition reactions, these aldehyde functional surfaces are grafted with triallylcyanurate, trimethylolpropane allyl ether, and vinyl chloroacetate. In the following, allyl-functional polymers (poly(butyl acrylate), pBA, Mn = 6990 g mol(-1) , Đ = 1.12 and poly(N-isopropyl acrylamide), pNIPAAm, Mn = 9500 g mol(-1) , Đ = 1.16) synthesized via reversible addition fragmentation chain transfer polymerization are conjugated to the celloluse surface in a UV-induced grafting-to approach. With pBA, hydrophobic cellulose sheets are obtained (water contact angle 116°), while grafting of pNIPAAm allows for generation of "smart" surfaces, which are hydrophilic at room temperature, but that become hydrophobic when heated above the characteristic lower critical solution temperature (93° contact angle). The Paterno-Büchi reaction has been shown to be a versatile synthetic tool that also performs well in grafting-to approaches whereby its overall performance seems to be close to that of radical thiol-ene reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ischemia and reperfusion injury in renal transplantation: hemodynamic and immunological paradigms

PubMed Central

Requião-Moura, Lúcio Roberto; Durão, Marcelino de Souza; de Matos, Ana Cristina Carvalho; Pacheco-Silva, Alvaro

2015-01-01

Ischemia and reperfusion injury is an inevitable event in renal transplantation. The most important consequences are delayed graft function, longer length of stay, higher hospital costs, high risk of acute rejection, and negative impact of long-term follow-up. Currently, many factors are involved in their pathophysiology and could be classified into two different paradigms for education purposes: hemodynamic and immune. The hemodynamic paradigm is described as the reduction of oxygen delivery due to blood flow interruption, involving many hormone systems, and oxygen-free radicals produced after reperfusion. The immune paradigm has been recently described and involves immune system cells, especially T cells, with a central role in this injury. According to these concepts, new strategies to prevent ischemia and reperfusion injury have been studied, particularly the more physiological forms of storing the kidney, such as the pump machine and the use of antilymphocyte antibody therapy before reperfusion. Pump machine perfusion reduces delayed graft function prevalence and length of stay at hospital, and increases long-term graft survival. The use of antilymphocyte antibody therapy before reperfusion, such as Thymoglobulin™, can reduce the prevalence of delayed graft function and chronic graft dysfunction. PMID:25993079

Radical graft polymerization of an Allyl Monomer onto Hydrophilic Polymers and their antibacterial nanofibrous membranes

USDA-ARS?s Scientific Manuscript database

Hydrophilic poly (vinyl alcohol-co-ethylene) (PVA-co-PE) copolymers with 27 mol %, 32 mol % and 44 mol % ethylene were functionalized by melt radical graft copolymerization with 2,4-diamino-6-diallylamino-1,3,5-triazine (NDAM) using reactive extrusion. This functionalization imparts antibacterial pr...

Elaboration of nano-structured grafted polymeric surface.

PubMed

Vrlinic, Tjasa; Debarnot, Dominique; Mozetic, Miran; Vesel, Alenka; Kovac, Janez; Coudreuse, Arnaud; Legeay, Gilbert; Poncin-Epaillard, Fabienne

2011-10-15

The surface grafting of multi-polymeric materials can be achieved by grafting as components such as polymers poly(N-isopropylacrylamide) and/or surfactant molecules (hexatrimethylammonium bromide, polyoxyethylene sorbitan monolaurate). The chosen grafting techniques, i.e. plasma activation followed by coating, allow a large spectrum of functional groups that can be inserted on the surface controlling the surface properties like adhesion, wettability and biocompatibility. The grafted polypropylene surfaces were characterized by contact angle analyses, XPS and AFM analyses. The influence of He plasma activation, of the coating parameters such as concentrations of the various reactive agents are discussed in terms of hydrophilic character, chemical composition and morphologic surface heterogeneity. The plasma pre-activation was shown inevitable for a permanent polymeric grafting. PNIPAM was grafted alone or with a mixture of the surfactant molecules. Depending on the individual proportion of each component, the grafted surfaces are shown homogeneous or composed of small domains of one component leading to a nano-structuration of the grafted surface. Copyright © 2011 Elsevier Inc. All rights reserved.

Modification of carbon fiber surfaces via grafting with Meldrum's acid

NASA Astrophysics Data System (ADS)

Cuiqin, Fang; Jinxian, Wu; Julin, Wang; Tao, Zhang

2015-11-01

The mechanism of Meldrum's acid modifying carbon fiber surfaces was investigated in this work. The existing carbonyl groups of carbon fibers were grafted with Meldrum's acid to create carboxylic functionalized surfaces. The surface functionalization effect was detected with X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscopy (AFM), and thermogravimetric analysis (TGA). The XPS results showed that the relative content of carboxylic groups on carbon fiber surfaces was increased from initial 1.41% to 7.84%, however, that of carbonyl groups was decreased from 23.11% to 13.28% after grafting reaction. The SEM, AFM and TGA results indicated that the surfaces of carbon fibers neither etched nor generated coating. The tensile strength of carbon fibers was preserved after grafting reaction according to single fiber tensile strength tests. The fibers were well combined with matrix and the maximal interlaminar shear strength (ILSS) of carbon fiber/epoxy resin composites was sharply increased approximately 74% after functionalization. The effects of acetic acid and sonication on the degree of the surface functionalization were also studied.

Results of a Seven-Year, Single-Centre Experience of the Long-Term Outcomes of Bovine Ureter Grafts Used as Novel Conduits for Haemodialysis Fistulas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Neelan, E-mail: neelan.das@gmail.com; Bratby, Mark J.; Shrivastava, Vivek

2011-10-15

Purpose: To report the long-term outcomes of bovine ureter grafts as novel conduits for haemodialysis fistulas. Materials and Methods: Thirty-five patients underwent placement of a total of 40 SynerGraft 100 (SG100; CryoLife Europa{sup Registered-Sign}, Guildford, UK) bovine ureter grafts between April 2002 and February 2009. Prospective data were collected on all patients, including active surveillance with blood flow studies and 6-monthly duplex ultrasound studies. Main outcome measures were primary and secondary patency rates. Results: Mean follow-up time was 97 weeks (range 4-270). Thirteen patients died from unrelated causes during the study period; 12 of these patients had a functioning graftmore » at the time of death. Five patients underwent transplantation, and all had a functioning graft at transplantation. Twelve patients had a functioning graft at the end of the study period. One hundred and ten stenoses were detected, and 97 venoplasty procedures were performed. Of the stenoses, 41.8% were located at the venous anastomosis, 12.7% within the graft, 17.3% in the outflow veins, and 28.1% in central veins. No arterial stenoses were detected. Primary patency rates were 53% at 6 months and 14% at 1 year. Secondary patency rates were 81% at 6 months, 75% at 1 year, and 56% at 2 years. Conclusions: Active surveillance and intervention was able to achieve satisfactory long-term secondary patency for these novel conduits compared with those made of PTFE seen in other studies.« less

Noninvasive imaging of islet grafts using positron-emission tomography

NASA Astrophysics Data System (ADS)

Lu, Yuxin; Dang, Hoa; Middleton, Blake; Zhang, Zesong; Washburn, Lorraine; Stout, David B.; Campbell-Thompson, Martha; Atkinson, Mark A.; Phelps, Michael; Gambhir, Sanjiv Sam; Tian, Jide; Kaufman, Daniel L.

2006-07-01

Islet transplantation offers a potential therapy to restore glucose homeostasis in type 1 diabetes patients. However, islet transplantation is not routinely successful because most islet recipients gradually lose graft function. Furthermore, serological markers of islet function are insensitive to islet loss until the latter stages of islet graft rejection. A noninvasive method of monitoring islet grafts would aid in the assessment of islet graft survival and the evaluation of interventions designed to prolong graft survival. Here, we show that recombinant adenovirus can engineer isolated islets to express a positron-emission tomography (PET) reporter gene and that these islets can be repeatedly imaged by using microPET after transplantation into mice. The magnitude of signal from engineered islets implanted into the axillary cavity was directly related to the implanted islet mass. PET signals attenuated over the following weeks because of the transient nature of adenovirus-mediated gene expression. Because the liver is the preferred site for islet implantation in humans, we also tested whether islets could be imaged after transfusion into the mouse liver. Control studies revealed that both intrahepatic islet transplantation and hyperglycemia altered the biodistribution kinetics of the PET probe systemically. Although transplanted islets were dispersed throughout the liver, clear signals from the liver region of mice receiving PET reporter-expressing islets were detectable for several weeks. Viral transduction, PET reporter expression, and repeated microPET imaging had no apparent deleterious effects on islet function after implantation. These studies lay a foundation for noninvasive quantitative assessments of islet graft survival using PET. diabetes | transplantation

The influence of immune system stimulation on encapsulated islet graft survival.

PubMed

Orłowski, Tadeusz M; Godlewska, Ewa; Tarchalska, Magda; Kinasiewicz, Joanna; Antosiak, Magda; Sabat, Marek

2005-01-01

The aim of this study was to determine the influence activating of the recipient immune system on the function of microencapsulated islet xenografts. The skin of WAG or Fisher rats and WAG free or encapsulated (APA) Langerhans islets were transplanted to healthy or to streptozotocin diabetic BALB/c mice. Skin grafts were performed following the method of Billingham and Medawar. Rat islets were isolated from pancreas by the Lacy and Kostianovsy method and encapsulated with calcium alginate-poly-L-lysine-alginate according to the 3-step coating method of Sun. The transplantation of encapsulated WAG islets, despite activation of the host immune system, restored euglycemia for over 180 +/-100 days. A subsequent skin graft taken from the same donor was rejected in the second set mode, but euglycemia persisted. In diabetic recipients, impaired immune response was corrected by successful encapsulated islet transplantation. In diabetic mice, strong stimulation with 2-fold skin transplantation induced primary non-function of grafted islets despite their encapsulation. The survival of an islet xenograft depends on the level of activation of the recipient immune system. The immune response of diabetic mice was impaired, but increased after post-transplant restitution of euglycemia. Microencapsulation sufficiently protected grafted islets, and remission of diabetes was preserved. However, after strong specific or non-specific stimulation of the host immune system, non-function of xenografted islets developed despite their encapsulation. Therefore, islet graft recipients should avoid procedures which could stimulate their immune systems. If absolutely necessary, the graft should be protected by exogenous insulin therapy at that time.

Five-Year Follow-Up on Transplanted Organs From Donors After Brain Death After Acute Stroke.

PubMed

Spatenkova, Vera; Pokorna, Eva; Suchomel, Petr

2017-08-01

Efficient intensive care donor management can help alleviate the shortage of organs for transplant. The aim of this study was to investigate the efficiency of management of donors after brain death from our neurointensive care unit. We conducted a prospective observational 5-year follow-up on 29 transplanted organs from 14 brain-dead donors after acute stroke (7 subarachnoid and 4 intracerebral hemorrhages, 3 ischemic strokes). Mean age of donors was 56.2 ± 8.70 years, and mean number of days of artificial ventilation was 5.0 ± 3.84. We transplanted 27 kidneys and 2 livers to 29 patients with mean age of 55.3 ± 9.76 years. No hearts or lungs were transplanted from these donors. Of the 27 patients who underwent kidney transplant, 21 patients (78%) lived 5 years; of those, 17 patients (63%) had functional grafts. One patient (4%) had a primary afunctional graft, and 3 patients (11%) had graft rejection (at 3, 15, and 41 mo). Six patients (22%) died after kidney transplant, with 1 patient in this group having a functional graft, 1 patient having a primary afunctional graft, and 4 patients (15%) having graft rejection (at 1, 12, 44, and 56 mo). The 2 patients with liver transplants lived 5 years with functional grafts. The 5-year follow-up showed that organs from 14 brain-dead donors improved and saved 19 lives, with 17 patients receiving kidney transplants and 2 patients receiving liver transplants. Another 7 patients had only partially improved quality of life.

Molecular Level Characterization of the Structure and Interactions in Peptide-Functionalized Metal-Organic Frameworks.

PubMed

Todorova, Tanya K; Rozanska, Xavier; Gervais, Christel; Legrand, Alexandre; Ho, Linh N; Berruyer, Pierrick; Lesage, Anne; Emsley, Lyndon; Farrusseng, David; Canivet, Jérôme; Mellot-Draznieks, Caroline

2016-11-07

We use density functional theory, newly parameterized molecular dynamics simulations, and last generation 15 N dynamic nuclear polarization surface enhanced solid-state NMR spectroscopy (DNP SENS) to understand graft-host interactions and effects imposed by the metal-organic framework (MOF) host on peptide conformations in a peptide-functionalized MOF. Focusing on two grafts typified by MIL-68-proline (-Pro) and MIL-68-glycine-proline (-Gly-Pro), we identified the most likely peptide conformations adopted in the functionalized hybrid frameworks. We found that hydrogen bond interactions between the graft and the surface hydroxyl groups of the MOF are essential in determining the peptides conformation(s). DNP SENS methodology shows unprecedented signal enhancements when applied to these peptide-functionalized MOFs. The calculated chemical shifts of selected MIL-68-NH-Pro and MIL-68-NH-Gly-Pro conformations are in a good agreement with the experimentally obtained 15 N NMR signals. The study shows that the conformations of peptides when grafted in a MOF host are unlikely to be freely distributed, and conformational selection is directed by strong host-guest interactions. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Abaca/polyester nonwoven fabric functionalization for metal ion adsorbent synthesis via electron beam-induced emulsion grafting

NASA Astrophysics Data System (ADS)

Madrid, Jordan F.; Ueki, Yuji; Seko, Noriaki

2013-09-01

A metal ion adsorbent was developed from a nonwoven fabric trunk material composed of both natural and synthetic polymers. A pre-irradiation technique was used for emulsion grafting of glycidyl methacrylate (GMA) onto an electron beam irradiated abaca/polyester nonwoven fabric (APNWF). The dependence of degree of grafting (Dg), calculated from the weight of APNWF before and after grafting, on absorbed dose, reaction time and monomer concentration were evaluated. After 50 kGy irradiation with 2 MeV electron beam and subsequent 3 h reaction with an emulsion consisting of 5% GMA and 0.5% polyoxyethylene sorbitan monolaurate (Tween 20) surfactant in deionized water at 40 °C, a grafted APNWF with a Dg greater than 150% was obtained. The GMA-grafted APNWF was further modified by reaction with ethylenediamine (EDA) in isopropyl alcohol at 60 °C to introduce amine functional groups. After a 3 h reaction with 50% EDA, an amine group density of 2.7 mmole/gram adsorbent was achieved based from elemental analysis. Batch adsorption experiments were performed using Cu2+ and Ni2+ ions in aqueous solutions with initial pH of 5 at 30 °C. Results show that the adsorption capacity of the grafted adsorbent for Cu2+ is four times higher than Ni2+ ions.

Urinary MicroRNA as Biomarker in Renal Transplantation.

PubMed

van de Vrie, M; Deegens, J K; Eikmans, M; van der Vlag, J; Hilbrands, L B

2017-05-01

Urine represents a noninvasive source in which proteins and nucleic acids can be assessed. Such analytes may function as biomarkers to monitor kidney graft pathology at every desired frequency, thereby providing a time window to prevent graft damage by therapeutic intervention. Recently, several proteins have been measured in urine as markers of graft injury. However, the specificity is limited, and measuring urinary proteins generally lacks the potential to predict early kidney graft damage. Currently, urinary mRNA and microRNA are being investigated to evaluate the prognostic value of changes in gene expression during the initial stages of graft damage. At such time point, a change in treatment regimen and dosage is expected to have maximum potency to minimize future decline in graft function. Both mRNA and microRNAs have shown promising results in both detection and prediction of graft injury. An advantage of microRNAs compared to mRNA molecules is their stability, a characteristic that is beneficial when working with urine samples. In this review, we provide the current state of urinary biomarkers in renal transplantation, with a focus on urinary microRNA. In addition, we discuss the methods used to study urinary microRNA expression. © 2016 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of American Society of Transplant Surgeons.

Can zero-hour cortical biopsy predict early graft outcomes after living donor renal transplantation?

PubMed

Rathore, Ranjeet Singh; Mehta, Nisarg; Mehta, Sony Bhaskar; Babu, Manas; Bansal, Devesh; Pillai, Biju S; Sam, Mohan P; Krishnamoorthy, Hariharan

2017-11-01

The aim of this study was to identify relevance of subclinical pathological findings in the kidneys of living donors and correlate these with early graft renal function. This was a prospective study on 84 living donor kidney transplant recipients over a period of two years. In all the donors, cortical wedge biopsy was taken and sent for assessment of glomerular, mesangial, and tubule status. The graft function of patients with normal histology was compared with those of abnormal histological findings at one, three, and six months, and one year post-surgery. Most abnormal histological findings were of mild degree. Glomerulosclerosis (GS, 25%), interstitial fibrosis (IF, 13%), acute tubular necrosis (ATN 5%), and focal tubal atrophy (FTA, 5%) were the commonly observed pathological findings in zero-hour biopsies. Only those donors who had histological changes of IF and ATN showed progressive deterioration of renal function at one month, three months, six months, and one year post-transplantation. In donors with other histological changes, no significant effect on graft function was observed. Zero-hour cortical biopsy gave us an idea of the general status of the donor kidney and presence or absence of subclinical pathological lesions. A mild degree of subclinical and pathological findings on zero-hour biopsy did not affect early graft renal function in living donor kidney transplantation. Zero-hour cortical biopsy could also help in discriminating donor-derived lesions from de novo alterations in the kidney that could happen subsequently.

Assessing the metabolic effects of calcineurin inhibitors in renal transplant recipients by urine metabolic profiling.

PubMed

Diémé, Binta; Halimi, Jean Michel; Emond, Patrick; Büchler, Matthias; Nadal-Desbarat, Lydie; Blasco, Hélène; Le Guellec, Chantal

2014-07-27

Biomarkers that can predict graft function and/or renal side effects of calcineurin inhibitors (CNI) at each stage of treatment in kidney transplantation are still lacking. We report the first untargeted GC-MS-based metabolomic study on urines of renal transplant patients. This approach would bring insight in biomarkers useable for graft function monitoring. All consecutive patients receiving a kidney allograft in our transplantation department over a 6-month period were prospectively included and followed up for 12 months. We collected urine samples on the seventh day (D7) after transplantation, then at month 3 (M3) and month 12 (M12), and obtained mass-spectrometry-based urinary metabolic profiles. Multivariate analyses were conducted to compare metabolic profiles at the 3 different periods and to assess potential differences between cyclosporine and tacrolimus. Differences in metabolic signatures were also assessed according to graft function at D7 and renal function at M3 and M12. The urinary metabolic patterns varied over time in cyclosporine- and tacrolimus-treated patients and were somewhat different at D7, M3, and M12 between the 2 treatment groups. Principal metabolites that differed, regardless of the treatment used, were mainly sugars, inositol, and hippuric acid. Interestingly, among tacrolimus-treated patients, different metabolic signatures were found between patients with immediate or delayed graft function at D7. Urinary metabolomics represents a noninvasive way of monitoring immunosuppressive therapy in renal transplant patients. Although it is too early to consider it as a biomarker of CNI-induced injury or graft function, metabolomics appears a promising evaluation tool in this area.

Radiation-grafting of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) onto silicone rubber

NASA Astrophysics Data System (ADS)

Flores-Rojas, G. G.; Bucio, E.

2016-10-01

Silicone rubber (SR) was modified with a graft of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) using either gamma-radiation or azobisisobutyronitrile (AIBN). The graft efficiency was evaluated as a function of monomer concentration, absorbed dose, reaction temperature, and concentration of AIBN. The hydrophilicity of the grafted films was measured by contact angle and their equilibrium swelling time in ethanol. Additional characterization by infrared (FTIR-ATR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is also reported.

Effect of a single intraoperative high-dose ATG-Fresenius on delayed graft function in donation after cardiac-death donor renal allograft recipients: a randomized study.

PubMed

van den Hoogen, Martijn W F; Kho, Marcia M L; Abrahams, Alferso C; van Zuilen, Arjan D; Sanders, Jan-Stephan; van Dijk, Marja; Hilbrands, Luuk B; Weimar, Willem; Hoitsma, Andries J

2013-04-01

Reducing the incidence of delayed graft function after transplant with donation after cardiac death donor renal allografts would facilitate managing recipients during their first weeks after a transplant. To reduce this incidence, in most studies, induction therapy with depleting anti-T-lymphocyte antibodies is coupled with a reduction of the dosage of the calcineurin inhibitor. The separate effect of anti-T-cell therapy on the incidence and duration of delayed graft function is therefore difficult to assess. We performed a randomized study to evaluate the effect of a single intraoperative high-dose of anti-T-lymphocyte immunoglobulin (ATG)-Fresenius (9 mg/kg body weight) on the incidence of delayed graft function. Eligible adult recipients of a first donation after cardiac death donor renal allograft were randomly assigned to ATG-Fresenius or no induction therapy. Maintenance immunosuppression consisted of tacrolimus, in an unadjusted dose, mycophenolate mofetil, and steroids. The study was prematurely terminated because of a lower-than-anticipated inclusion rate. Baseline characteristics were comparable in the ATG-Fresenius group (n=28) and the control group (n=24). Twenty-two patients in the ATG-Fresenius group (79%) had delayed graft function, compared with 13 in the control group (54%; P = .06). Allograft and patient survival were comparable in both groups. Serious adverse events occurred more frequently in the ATG-Fresenius group than they did in the control group (57% vs 29%; P < .05). Intraoperative administration of a single high-dose of ATG-Fresenius in donation after cardiac death donor renal allograft recipients, followed by triple immunosuppression with an unadjusted tacrolimus dose, seems ineffective to reduce the incidence of delayed graft function. Moreover, this was associated with a higher rate of serious adverse events (EudraCT-number, 2007-000210-36.).

Relative reductions in soluble CD30 levels post-transplant predict acute graft function in islet allograft recipients receiving three different immunosuppression protocols.

PubMed

Hire, Kelly; Hering, Bernhard; Bansal-Pakala, Pratima

2010-08-01

Despite advances in islet transplantation, challenges remain in monitoring for anti-islet immune responses. Soluble CD30 (sCD30) has been investigated as a predictor of acute rejection in kidney, lung, and heart transplantation as well as in a single study in human islet cell recipients. In this study, sCD30 levels were retrospectively assessed in 19 allograft recipients treated with three different immunosuppression induction therapies. Soluble CD30 levels were assessed at pre-transplant; early post-transplant (day 4-day 7); one-month post-transplant; and late post-transplant (day 90-day 120) and then correlated with eventual graft outcomes at 1-year follow-up. Results showed no correlation between mean serum sCD30 levels at any point in time pre- or post-transplant and graft function at 1-year follow-up. However, analysis demonstrated that mean sCD30 levels at day 28 or day 90-day 120 decreased from pre-transplant levels in recipients with long-term islet allograft function compared to recipients with partial or non-graft function (a decrease of 43.6+/-25.6% compared to 16.7+/-35.2%, p<0.05). In another finding, immunosuppression with the ATG protocol led to a greater reduction in sCD30 levels post-transplant overall. A larger reduction post-transplant correlated with full graft function. The results demonstrate that a relative reduction in sCD30 levels post-transplant may be applicable as a biomarker to monitor graft function in islet allograft recipients. Additionally, knowledge of the impact of various immunosuppression protocols on the timing and extent of changes in post-transplant sCD30 levels could aid in patient-specific tailoring of immunosuppression. Copyright © 2010 Elsevier B.V. All rights reserved.

Local delivery of glial cell line-derived neurotrophic factor improves facial nerve regeneration after late repair.

PubMed

Barras, Florian M; Kuntzer, Thierry; Zurn, Anne D; Pasche, Philippe

2009-05-01

Facial nerve regeneration is limited in some clinical situations: in long grafts, by aged patients, and when the delay between nerve lesion and repair is prolonged. This deficient regeneration is due to the limited number of regenerating nerve fibers, their immaturity and the unresponsiveness of Schwann cells after a long period of denervation. This study proposes to apply glial cell line-derived neurotrophic factor (GDNF) on facial nerve grafts via nerve guidance channels to improve the regeneration. Two situations were evaluated: immediate and delayed grafts (repair 7 months after the lesion). Each group contained three subgroups: a) graft without channel, b) graft with a channel without neurotrophic factor; and c) graft with a GDNF-releasing channel. A functional analysis was performed with clinical observation of facial nerve function, and nerve conduction study at 6 weeks. Histological analysis was performed with the count of number of myelinated fibers within the graft, and distally to the graft. Central evaluation was assessed with Fluoro-Ruby retrograde labeling and Nissl staining. This study showed that GDNF allowed an increase in the number and the maturation of nerve fibers, as well as the number of retrogradely labeled neurons in delayed anastomoses. On the contrary, after immediate repair, the regenerated nerves in the presence of GDNF showed inferior results compared to the other groups. GDNF is a potent neurotrophic factor to improve facial nerve regeneration in grafts performed several months after the nerve lesion. However, GDNF should not be used for immediate repair, as it possibly inhibits the nerve regeneration.

Alcohol abuse in deceased liver donors: impact on post-transplant outcomes.

PubMed

Mangus, Richard S; Kubal, Chandrashekhar A; Fridell, Jonathan A; Pena, Jose M; Frost, Evan M; Joseph Tector, A

2015-01-01

Many deceased liver donors with a history of alcohol abuse are excluded based upon medical history alone. This paper summarizes the transplant outcomes for a large number of deceased liver donors with a documented history of alcohol abuse. The records for 1478 consecutive deceased liver donors were reviewed (2001-2012). As per the United Network for Organ Sharing criteria, heavy alcohol use by an organ donor is defined as chronic intake of two or more drinks per day. Donors with a documented history of alcohol abuse were divided into three groups according to duration of abuse (<10 years, 10-24 years and 25 + years). Reperfusion biopsies are reported. Outcomes include biopsy appearance, early graft function and early and late graft survival. There were 161 donors with alcohol abuse: <10 years (29%); 10-24 years (42%); and ≥25 years (29%). Risk of 90-day graft loss for these three groups was: 0%, 3% and 2%, compared to 3% for all other donors (P = 0.62). Graft survival at 1 year for donor grafts with and without alcohol abuse was 89% and 87% (P = 0.52). There was no difference in early graft function. Cox proportional hazards modelling for graft survival demonstrates no statistically significant difference in survival up to 10 years post-transplant. This study demonstrates successful transplantation of a large number of deceased donor liver grafts from donors with a documented history of alcohol abuse (n = 161; 11% of all grafts). These extended criteria donor allografts may, therefore, be utilized successfully with similar outcomes. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Preservation of anal function after total excision of the anal mucosa for Bowen's disease.

PubMed Central

Reynolds, V H; Madden, J J; Franklin, J D; Burnett, L S; Jones, H W; Lynch, J B

1984-01-01

Six women with Bowen's disease of the anogenital area were treated by total excision of the anal mucosa, perianal skin and, in some cases, partial vulvectomy. Two patients had foci of microinvasive squamous carcinoma. Adequate tumor margins were determined by frozen sections. The resulting mucosal and cutaneous defects were grafted with medium split-thickness skin grafts applied to the anal canal and sutured circumferentially to the rectal mucosa. Grafts were held in place by a finger cot inserted in the anal canal and stuffed with cotton balls. Patients were constipated five or six days with codeine. The skin grafts healed per primam. One additional patient was similarly treated for a chronic herpetic ulceration of the anus and healed. Contrary to dire predictions, all patients were able to distinguish between gaseous and solid rectal contents and sphincter function was preserved. In one patient, Bowen's disease has recurred in the grafted perianal skin. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:6372711

Active range of motion outcomes after reconstruction of burned wrist and hand deformities.

PubMed

Afifi, Ahmed M; Mahboub, Tarek A; Ibrahim Fouad, Amr; Azari, Kodi; Khalil, Haitham H; McCarthy, James E

2016-06-01

This works aim is to evaluate the efficacy of skin grafts and flaps in reconstruction of post-burn hand and wrist deformities. A prospective study of 57 burn contractures of the wrist and dorsum of the hand was performed. Flaps were used only if there was a non-vascularized structure after contracture release, otherwise a skin graft was used. Active range of motion (ROM) was used to assess hand function. The extension deformity cohort uniformly underwent skin graft following contracture release with a mean improvement of 71 degrees (p<0.0001). The flexion deformity cohort was treated with either skin grafts (8 patients) or flaps (9 patients) with a mean improvement of 44 degrees (p<0.0001). Skin grafts suffice for dorsal hand contractures to restore functional wrist ROM. For flexion contractures, flaps were more likely for contractures >6 months. Early release of burn contracture is advisable to avoid deep structure contracture. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Coronary artery surgery: indications and recent experience.

PubMed Central

Robinson, P. S.; Coltart, D. J.; Jenkins, B. S.; Webb-Peploe, M. M.; Braimbridge, M. V.; Williams, B. T.

1978-01-01

The comprehensive experience of coronary artery surgery in a Cardiothoracic Unit over a 31-month period is reviewed. Hospital mortality for elective bypass grafting was 3.9% overall and 2.5% in those with good pre-operative left ventricular function. Major influences on hospital mortality were pre-operative left ventricular function, extent of coronary artery disease and extent of the surgical procedure undertaken in terms of number of aortocoronary grafts inserted, coronary endarterectomy and particularly concomitant valve surgery or aneurysm resection. Follow-up experience shows 74% of grafted patients to be symptom-free and 85% symptomatically improved one year after surgery with 70% symptom-free and 80% improved at two years. Early post-operative deaths appear related to early graft closure and recurrence of symptoms postoperatively to late graft closure or progression of coronary disease in the native circulation. The study provides a guide to the relative risks of coronary artery surgery for symptomatic coronary artery disease and expected symptomatic results in the early follow-up period. PMID:310999

Surface functionalization of cyclic olefin copolymer with aryldiazonium salts: A covalent grafting method

NASA Astrophysics Data System (ADS)

Brisset, Florian; Vieillard, Julien; Berton, Benjamin; Morin-Grognet, Sandrine; Duclairoir-Poc, Cécile; Le Derf, Franck

2015-02-01

Covalent immobilization of biomolecules on the surface of cyclic olefin copolymer (COC) is still a tough challenge. We developed a robust method for COC surface grafting through reaction with aryldiazonium. Chemical diazonium reduction generated an aryl radical and the formation of a grafted film layer on the organic surface. We also demonstrated that the chemical reduction of diazonium salt was not sufficient to form a film on the COC surface. UV illumination had to be combined with chemical reduction to graft an aryl layer onto the COC surface. We optimized organic film deposition by using different chemical reducers, different reaction times and reagent proportions. We characterized surface modifications by fluorescence microscopy and contact angle measurements, infrared spectroscopy, X-ray photoemission spectroscopy and Raman spectroscopy, and assessed the topography of the aryl film by atomic force microscopy. This original strategy allowed us to evidence various organic functions to graft biomolecules onto COC surfaces with a fast and efficient technique.

Successful renal transplantation from a brain-dead deceased donor with head injury, disseminated intravascular coagulation and deranged renal functions.

PubMed

Ghuge, P P; Kute, V B; Vanikar, A V; Gumber, M R; Gera, D N; Patel, H V; Shah, P R; Modi, P R; Shah, V R; Trivedi, H L

2013-11-01

Deceased donors (DDs) with the brain death due to head injury are the major source of organs for transplantation. The incidence of post-head injury disseminated intravascular coagulation (DIC) ranges from 24% to 50%. Many centers do not accept organs from donors with DIC due to increased risk of primary graft non-function and/or high chances of morbidity/mortality. We performed two successful renal transplants from a DD with head injury with DIC and deranged renal function. One of the recipients developed transient thrombocytopenia, but there was no evidence of DIC or delayed graft functions in either of the recipients. Over a follow-up of 1 month, both are doing well with stable graft function and hematological profile. Thus, a carefully selected DD with severe DIC even with deranged renal function is not a contraindication for organ donation if other risk factors for primary non-function are excluded. This approach will also help in overcoming organ shortage.

Shoulder reconstruction after tumor resection by pedicled scapular crest graft.

PubMed

Amin, Sherif N; Ebeid, Walid A

2002-04-01

The current authors present and evaluate a technique for reconstructing proximal humeral defects that result after resection of malignant bone tumors. Sixteen patients were included in this study with an average followup of 3 years (range, 12-76 months). Twelve patients had intraarticular resections, two had extraarticular resections, and two had intercalary resections. Reconstruction was done at the lateral border of the scapula (based on the circumflex scapular vessels) that was osteotomized and mobilized to bridge the resultant defect. Shoulder arthrodesis was done in 14 patients and the shoulder was spared in the two patients who had intercalary resections. Function was evaluated according to the Musculoskeletal Tumor Society scoring system. The average time for union of the graft proximally and distally was 6 months after which the graft started to hypertrophy. The average functional score was 22.5 points (75%) with a minimum score of 18 points (60%) and a maximum score of 27 points (90%). Nonunion of the distal host-graft junction occurred in two patients; both patients required iliac crest bone grafting and both achieved clinical and radiographic union without additional intervention. In three patients, the proximal fixation became loose but had no effect on function. The authors conclude that this technique is inexpensive, effective, and a durable reconstructive option for proximal humeral defects that are less than 15 cm. It has a predictable functional outcome (60%-90%) that is comparable with other reconstructive options.

Impact of post-kidney transplant parathyroidectomy on allograft function

PubMed Central

Parikh, Samir; Nagaraja, Haikady; Agarwal, Anil; Samavedi, Srinivas; Von Visger, Jon; Nori, Uday; Andreoni, Kenneth; Pesavento, Todd; Singh, Neeraj

2013-01-01

Background The impact of parathyroidectomy on allograft function in kidney transplant patients is unclear. Methods We conducted a retrospective, observational study of all kidney transplant recipients from 1988 to 2008 who underwent parathyroidectomy for uncontrolled hyperparathyroidism (n = 32). Post-parathyroidectomy, changes in estimated glomerular filtration rate (eGFR) and graft loss were recorded. Cross-sectional associations at baseline between eGFR and serum calcium, phosphate, and parathyroid hormone (PTH), and associations between their changes within subjects during the first two months post-parathyroidectomy were assessed. Results Post-parathyroidectomy, the mean eGFR declined from 51.19 mL/min/1.73 m2 at parathyroidectomy to 44.78 mL/min/1.73 m2 at two months (p < 0.0001). Subsequently, graft function improved, and by 12 months, mean eGFR recovered to 49.76 mL/min/1.73 m2 (p = 0.035). Decrease in serum PTH was accompanied by a decrease in eGFR (p = 0.0127) in the first two months post-parathyroidectomy. Patients whose eGFR declined by ≥ 20% (group 1) in the first two months post-parathyroidectomy were distinguished from the patients whose eGFR declined by <20% (group 2). The two groups were similar except that group 1 had a higher baseline mean serum PTH compared with group 2, although not significant (1046.7 ± 1034.2 vs. 476.6 ± 444.9, p = 0.14). In group 1, eGFR declined at an average rate of 32% (p < 0.0001) during the first month post-parathyroidectomy compared with 7% (p = 0.1399) in group 2, and the difference between these two groups was significant (p = 0.0003). The graft function recovered in both groups by one yr. During median follow-up of 66.00 ± 49.45 months, 6 (18%) patients lost their graft with a mean time to graft loss from parathyroidectomy of 37.2 ± 21.6 months. The causes of graft loss were rejection (n = 2), pyelonephritis (n = 1) and chronic allograft nephropathy (n = 3). No graft loss occurred during the first-year post-surgery. Conclusion Parathyroidectomy may lead to transient kidney allograft dysfunction with eventual recovery of graft function by 12 months post-parathyroidectomy. Higher level of serum PTH pre-parathyoidectomy is associated with a more profound decrease in eGFR post-parathyroidectomy. PMID:23448282

Radiation grafting of acrylamide and maleic acid on chitosan and effective application for removal of Co(II) from aqueous solutions

NASA Astrophysics Data System (ADS)

Saleh, Alaaeldine Sh.; Ibrahim, Ahmed G.; Elsharma, Emad M.; Metwally, Essam; Siyam, Tharwat

2018-03-01

The graft copolymerization has been proven as a superior polymerization technique because it combines the functional advantages of the grafted and base polymers. In this work, the radiation-induced grafting of acrylamide (AAm) and maleic acid (MA) onto chitosan (CTS) was developed and optimized by determining the grafting percentage and efficiency as a function of grafting conditions such as AAm, MA, and CTS concentrations, and absorbed dose. Fourier transform infrared spectroscopic analysis (FTIR) confirmed the graft copolymerization. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) further characterized the grafted copolymers and showed their high thermal stability. Using batch sorption experiments and 60Co as a radiotracer, poly(CTS-AAm) and poly(CTS-MA) were evaluated for Co(II) removal from aqueous solutions. The Co(II) removal increases with increasing time, pH, polymer, and Co(II) concentrations. Experimentally, P(CTS-AAm) and P(CTS-MA) show high sorption capacities of Co(II), i.e. 150 mg g-1 and 421 mg g-1, respectively, which makes them potential sorbents of Co(II) for water and wastewater treatment. Finally, the Co(II) sorption was examined using sorption isotherm and kinetic models. The sorption was best fitted to Langmuir model which suggests the sorption is of chemisorption type. On the other hand, the sorption kinetics was best represented by Elovich model which also indicates the chemical nature of Co(II) sorption on P(CTS-AAm) and P(CTS-MA).

Double-layered collagen graft to the radial forearm free flap donor sites without skin graft.

PubMed

Park, Tae-Jun; Kim, Hong-Joon; Ahn, Kang-Min

2015-12-01

Radial forearm free flap is the most reliable flap for intraoral soft tissue reconstruction after cancer ablation surgery. However, unesthetic scar of the donor site and the need for a second donor site for skin graft are major disadvantages of the forearm flap. The purpose of this study was to report the clinical results of double-layered collagen graft to the donor site of the forearm free flap without skin graft. Twenty-two consecutive patients who underwent oral cancer ablation and forearm reconstruction between April 2010 and November 2013 were included in this study. Male to female ratio was 12:10, and average age was 61.0 years old (27-84). Double-layered collagen was grafted to the donor site of the forearm free flap and healed for secondary intention. Upper silicone had been trimmed at the periphery during secondary intention, and dry dressing was used. Postoperative scar healing and esthetic results and function were evaluated. An average follow-up period was 34.9 months. The scar area was decreased to 63.9 % in average. The complete healing was obtained between 1.5 and 3 months according to the defect size. There was no functional defect or impairment 3 months after operation. All patients were satisfied with the esthetic results. Three patients died of recurred cancer. Double-layered collagen graft was successfully performed in this study. Without the thigh skin graft, patients had experienced less painful postoperative healing periods and discomfort.

VAGINOPLASTY WITH AUTOLOGOUS BUCCAL MUCOSA FENESTRATED GRAFT IN TWO PATIENTS WITH VAGINAL AGENESIS: A MULTIDISCIPLINARY APPROACH AND LITERATURE REVIEW

PubMed Central

Chan, Jessica L; Levin, Pamela J; Ford, Brian P; Stanton, David C; Pfeifer, Samantha M

2017-01-01

The objective of this case series is to describe the procedure and outcomes of a multidisciplinary approach to vaginoplasty using autologous buccal mucosa fenestrated grafts in two patients with vaginal agenesis. This procedure resulted in anatomic success with a functional neovagina with good vaginal length and caliber and satisfactory sexual function capacity and well healed buccal mucosa. There were no complications and patients were satisfied with surgical results. We conclude that the use of a single fenestrated graft of autologous buccal mucosa is a simple, effective procedure for the treatment of vaginal agenesis that results in an optimally functioning neovagina with respect to vaginal length, caliber, and sexual capacity. PMID:28212868

Dual kidney transplant techniques: A systematic review.

PubMed

Cocco, Annelise; Shahrestani, Sara; Cocco, Nicholas; Hameed, Ahmer; Yuen, Lawrence; Ryan, Brendan; Hawthorne, Wayne; Lam, Vincent; Pleass, Henry

2017-08-01

Dual kidney transplantation (DKT) was developed to improve outcomes from transplantation of extended criteria donors (ECD). This study examined which surgical techniques have been reported for DKT and whether any technique had superior patient and graft survival. Electronic databases were searched for published studies mapping to MESH terms: "kidney or renal" AND "transplan*" AND "dual or double." Single case reports, studies of patients less than 18 years old, studies which did not describe the surgical technique, and studies that did not report patient or graft survival were excluded. Fifteen reports of 434 DKT recipients were identified. Three techniques were described: bilateral placement; unilateral placement with separate anastomoses; and unilateral placement with patch anastomoses. Patient survival across all three techniques was over 95% at 1 year, and graft survival was also similar at over 90%. Rates of delayed graft function were between 20% and 30% across all techniques. The three techniques have equivalent delayed graft function as well as patient and graft survival rates. This is an encouraging result as it means that the surgeon can choose to use the technique which is most appropriate for their own skills and for the patient. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Surface grafted antibodies: controlled architecture permits enhanced antigen detection.

PubMed

Sebra, Robert P; Masters, Kristyn S; Bowman, Christopher N; Anseth, Kristi S

2005-11-22

The attachment of antibodies to substrate surfaces is useful for achieving specific detection of antigens and toxins associated with clinical and field diagnostics. Here, acrylated whole antibodies were produced through conjugation chemistry, with the goal of covalently photografting these proteins from surfaces in a controlled fashion, to facilitate rapid and sensitive antigenic detection. A living radical photopolymerization chemistry was used to graft the acrylated whole antibodies on polymer surfaces at controlled densities and spatial locations by controlling the exposure time and area, respectively. Copolymer grafts containing these antibodies were synthesized to demonstrate two principles. First, PEG functionalities were introduced to prevent nonspecific protein interactions and improve the reaction kinetics by increasing solvation and mobility of the antibody-containing chains. Both of these properties lead to sensitive (pM) and rapid (<20 min) detection of antigens with this surface modification technique. Second, graft composition was tailored to include multiple antibodies on the same grafted chains, establishing a means for simultaneously detecting multiple antigens on one grafted surface area. Finally, the addition of PEG spacers between the acrylate functionality and the pendant detection antibodies was tuned to enhance the detection of a short-half-life molecule, glucagon, in a complex biological environment, plasma.

An in vivo model of functional and vascularized human brain organoids.

PubMed

Mansour, Abed AlFatah; Gonçalves, J Tiago; Bloyd, Cooper W; Li, Hao; Fernandes, Sarah; Quang, Daphne; Johnston, Stephen; Parylak, Sarah L; Jin, Xin; Gage, Fred H

2018-06-01

Differentiation of human pluripotent stem cells to small brain-like structures known as brain organoids offers an unprecedented opportunity to model human brain development and disease. To provide a vascularized and functional in vivo model of brain organoids, we established a method for transplanting human brain organoids into the adult mouse brain. Organoid grafts showed progressive neuronal differentiation and maturation, gliogenesis, integration of microglia, and growth of axons to multiple regions of the host brain. In vivo two-photon imaging demonstrated functional neuronal networks and blood vessels in the grafts. Finally, in vivo extracellular recording combined with optogenetics revealed intragraft neuronal activity and suggested graft-to-host functional synaptic connectivity. This combination of human neural organoids and an in vivo physiological environment in the animal brain may facilitate disease modeling under physiological conditions.

Design of Chitosan-Grafted Carbon Nanotubes: Evaluation of How the –OH Functional Group Affects Cs+ Adsorption

PubMed Central

Yang, Shubin; Shao, Dadong; Wang, Xiangke; Hou, Guangshun; Nagatsu, Masaaki; Tan, Xiaoli; Ren, Xuemei; Yu, Jitao

2015-01-01

In order to explore the effect of –OH functional groups in Cs+ adsorption, we herein used the low temperature plasma-induced grafting method to graft chitosan onto carbon nanotubes (denoted as CTS-g-CNTs), as raw-CNTs have few functional groups and chitosan has a large number of –OH functional groups. The synthesized CTS-g-CNT composites were characterized using different techniques. The effect of –OH functional groups in the Cs+ adsorption process was evaluated by comparison of the adsorption properties of raw-CNTs with and without grafting chitosan. The variation of environmental conditions such as pH and contact time was investigated. A comparison of contaminated seawater and simulated groundwater was also evaluated. The results indicated that: (1) the adsorption of Cs+ ions was strongly dependent on pH and the competitive cations; (2) for CNT-based material, the –OH functional groups have a positive effect on Cs+ removal; (3) simulated contaminated groundwater can be used to model contaminated seawater to evaluate the adsorption property of CNTs-based material. These results showed direct observational evidence on the effect of –OH functional groups for Cs+ adsorption. Our findings are important in providing future directions to design and to choose effective material to remedy the removal of radioactive cesium from contaminated groundwater and seawater, crucial for public health and the human social environment. PMID:26006711

Formation and properties of surface-anchored polymer assemblies with tunable physico-chemical characteristics

NASA Astrophysics Data System (ADS)

Wu, Tao

We describe two new methodologies leading to the formation of novel surface-anchored polymer assemblies on solid substrates. While the main goal is to understand the fundamentals pertaining to the preparation and properties of the surface-bound polymer assemblies (including neutral and chargeable polymers), several examples also are mentioned throughout the Thesis that point out to practical applications of such structures. The first method is based on generating assemblies comprising anchored polymers with a gradual variation of grafting densities on solid substrates. These structures are prepared by first covering the substrate with a molecular gradient of the polymerization initiator, followed by polymerization from these substrate-bound initiator centers ("grafting from"). We apply this technique to prepare grafting density gradients of poly(acryl amide) (PAAm) and poly(acrylic acid) (PAA) on silica-covered substrates. We show that using the grafting density gradient geometry, the characteristics of surface-anchored polymers in both the low grafting density ("mushroom") regime as well as the high grafting density ("brush") regime can be accessed conveniently on a single sample. We use a battery of experimental methods, including Fourier transform infrared spectroscopy (FTIR), Near-edge absorption fine structure spectroscopy (NEXAFS), contact angle, ellipsometry, to study the characteristics of the surface-bound polymer layers. We also probe the scaling laws of neutral polymer as a function of grafting density, and for weak polyelectrolyte, in addition to the grafting density, we study the affect of solution ionic strength and pH values. In the second novel method, which we coined as "mechanically assisted polymer assembly" (MAPA), we form surface anchored polymers by "grafting from" polymerization initiators deposited on elastic surfaces that have been previously extended uniaxially by a certain length increment, Deltax. Upon releasing the strain in the substrate after completion of polymerization, we show the grafting density of the polymers grafted to flexible substrates can be tuned as a function of Deltax.

Postconditioning effects of argon or xenon on early graft function in a porcine model of kidney autotransplantation.

PubMed

De Deken, J; Rex, S; Lerut, E; Martinet, W; Monbaliu, D; Pirenne, J; Jochmans, I

2018-07-01

Ischaemia-reperfusion injury is inevitable during renal transplantation and can lead to delayed graft function and primary non-function. Preconditioning, reconditioning and postconditioning with argon and xenon protects against renal ischaemia-reperfusion injury in rodent models. The hypothesis that postconditioning with argon or xenon inhalation would improve graft function in a porcine renal autotransplant model was tested. Pigs (n = 6 per group) underwent left nephrectomy after 60 min of warm ischaemia (renal artery and vein clamping). The procured kidney was autotransplanted in a separate procedure after 18 h of cold storage, immediately after a right nephrectomy. Upon reperfusion, pigs were randomized to inhalation of control gas (70 per cent nitrogen and 30 per cent oxygen), argon (70 per cent and 30 per cent oxygen) or xenon (70 per cent and 30 per cent oxygen) for 2 h. The primary outcome parameter was peak plasma creatinine; secondary outcome parameters included further markers of graft function (creatinine course, urine output), graft injury (aspartate aminotransferase, heart-type fatty acid-binding protein, histology), apoptosis and autophagy (western blot, terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) staining), inflammatory mediators and markers of cell survival/growth (mRNA and tissue protein quantification), and animal survival. Results are presented as median (i.q.r.). ANOVA and Kruskal-Wallis tests were used where indicated. Peak plasma creatinine levels were similar between the groups: control 20·8 (16·4-23·1) mg/dl, argon 21·4 (17·1-24·9) mg/dl and xenon 19·4 (17·5-21·0) mg/dl (P = 0·607). Xenon was associated with an increase in autophagy and proapoptotic markers. Creatinine course, urine output, injury markers, histology, survival and inflammatory mediators were not affected by the intervention. Postconditioning with argon or xenon did not improve kidney graft function in this experimental model. Surgical relevance Ischaemia-reperfusion injury is inevitable during renal transplantation and can lead to delayed graft function and primary non-function. Based on mainly small animal experiments, noble gases (argon and xenon) have been proposed to minimize this ischaemia-reperfusion injury and improve outcomes after transplantation. The hypothesis that postconditioning with argon or xenon inhalation would improve graft function was tested in a porcine kidney autotransplantation model. The peak plasma creatinine concentration was similar in the control, argon and xenon groups. No other secondary outcome parameters, including animal survival, were affected by the intervention. Xenon was associated with an increase in autophagy and proapoptotic markers. Despite promising results in small animal models, postconditioning with argon or xenon in a translational model of kidney autotransplantation was not beneficial. Clinical trials would require better results. © 2018 BJS Society Ltd Published by John Wiley & Sons Ltd.

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

PubMed

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

2004-05-01

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

Combining neurotrophin-transduced schwann cells and rolipram to promote functional recovery from subacute spinal cord injury.

PubMed

Flora, Govinder; Joseph, Gravil; Patel, Samik; Singh, Amanpreet; Bleicher, Drew; Barakat, David J; Louro, Jack; Fenton, Stephanie; Garg, Maneesh; Bunge, Mary Bartlett; Pearse, Damien D

2013-01-01

Following spinal cord injury (SCI), both an inhibitory environment and lack of intrinsic growth capacity impede axonal regeneration. In a previous study, prevention of cyclic adenosine monophosphate (AMP) hydrolysis by the phosphodiesterase-4 inhibitor rolipram, in combination with Schwann cell (SC) grafts, promoted significant supraspinal and proprioceptive fiber growth and/or sparing and improved locomotion. In another study, transplanted SCs transduced to generate a bifunctional neurotrophin (D15A) led to significant increases in graft SCs and axons, including supraspinal and myelinated axons. Here we studied the growth and myelination of local and supraspinal axons and functional outcome following the combination of rolipram administration and neurotrophin-transduced SC implantation after SCI. Rolipram was administered subcutaneously for 4 weeks immediately after contusion at vertebral T8 (25.0-mm weight drop, MASCIS impactor). GFP or GFP-D15A-transduced SCs were injected into the injury epicenter 1 week after SCI. GFP-D15A SC grafts and GFP SC grafts with rolipram contained significantly more serotonergic fibers compared to GFP SCs. SC myelinated axons were increased significantly in GFP SC with rolipram-treated animals compared to animals receiving SCI alone. Rolipram administered with either GFP or GFP-D15A SCs significantly increased numbers of brain stem-derived axons below the lesion/implant area and improved hindlimb function. Compared to the single treatments, the combination led to the largest SC grafts, the highest numbers of serotonergic fibers in the grafts, and increased numbers of axons from the reticular formation below the lesion/implant area and provided the greatest improvement in hindlimb function. These findings demonstrate the therapeutic potential for a combination therapy involving the maintenance of cyclic AMP levels and neurotrophin-transduced SCs to repair the subacutely injured spinal cord.

Ex-vivo perfusion machines in kidney transplantation. The significance of the resistivity index

PubMed Central

ELEC, FLORIN IOAN; LUCAN, CIPRIAN; GHERVAN, LIVIU; MUNTEANU, VALENTIN; MOGA, SILVIU; SUCIU, MIHAI; ENACHE, DAN; ELEC, ALINA; MUNTEANU, ADRIANA; BARBOS, ADRIAN; IACOB, GHEORGHITA; LUCAN, MIHAI

2014-01-01

Introduction With a growing shortage of organs for transplantation, finding ways of increasing the donor organ pool remains of utmost importance. Perfusion machines (PM) have been proven to enhance the potential for kidney transplants to function sooner, last longer, giving patients the opportunity for a better life quality. Objective The aim of this study is to evaluate the relation between the resistance index provided by the PM, the postoperative resistance index measured by Doppler ultrasound and the initial graft outcome. Material and method Between January 2012-December 2012, clinical data obtained from 82 consecutive renal transplants from brain death donors (BDD) which underwent PM maintenance were analyzed in a transversal study. Prior transplantation we recorded the solution temperature, filtration rate and the resistance index provided by PM. After the surgical intervention, each patient had standard follow-up. Doppler ultrasound resistivity index (RI) was recorded on the first postoperative day. Results Out of 115 renal transplants, 98 (85.21%) were performed with grafts from BDD. The PM was used for 82 renal grafts. The Doppler resistance index in relation to the resistance index shows a highly statistical correlation by linear regression (R=0.813, p<0.0001). Primary graft function was recorded in 74 patients (90.24%) and it was highly statistically significant correlated with the resistance index measured by PM. Out of 8 patients with primary non-function, 6 patients recovered with normal graft function at one year. Conclusion The resistivity index recorded by the life-port machine is correlated with the vascular resistivity index measured by Doppler ultrasound and thus it may predicts the primary graft outcome. PMID:26527992

Grafting of vinyl acetate-ethylacrylate binary monomer mixture onto guar gum.

PubMed

Singh, Vandana; Singh, Angela; Joshi, Sneha; Malviya, Tulika

2016-03-01

Present article reports on guar gum (GG) functionalization through graftcopolymerization of vinylacetate (VAC) and ethylacrylate (EA) from their binary mixtures. The potassium persulfate/ascorbic acid (KPS/AA) redox initiator system has been used for the binary grafting under the previously optimized conditions for VAC grafting at guar gum. The concentration of ascorbic acid (AA), persulfate (KPS), and grafting temperature were varied to optimize the binary grafting. A preliminary investigation revealed that the copolymer has excellent ability to capture Hg(II) from aqueous solution. It was observed that the optimum % grafting sample (CP3) was best at Hg(II) adsorption. CP3 and mercury loaded CP3 (CP3-Hg) have been extensively characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Thermo gravimetric analysis (TGA) and a plausible mechanism for the grafting has been proposed. Copyright © 2015 Elsevier B.V. All rights reserved.

Applications of functional polymer brushes for nanoparticle uptake and prevention of protein adsorption

NASA Astrophysics Data System (ADS)

Arifuzzaman, Shafi M.

The central theme of this Ph.D. dissertation is to develop novel multifunctional polymer coatings for understanding partition of proteins and nanoparticles on polymers grafted to flat surfaces (so-called brushes). Systematic investigation of the adsorption phenomena is accomplished by utilizing surface-anchored assemblies comprising grafted polymers with variation in physical properties (i.e., length or/and grafting density) and chemical functionality. The chemical composition of the brush is tailored by either "chemical coloring" of a parent homopolymer brush with selective chemical moieties or by sequential growth of two chemically dissimilar polymer blocks. We present preparation of two types of tailor-made, surface-grafted copolymers: (1) those composed of hydrophilic and hydrophobic blocks (so-called amphiphilic polymer brushes), and (2) those comprising of anionic and cationic polymer segments (so-called polyampholyte brushes). We describe the organization of functionality in the grafted polymer brushes and the partitioning of proteins and nanoparticles using a battery of complementary analytical probes. Specifically, we address how varying the molecular weight, grafting density, and chemical composition of the brush affects adsorbtion and desorbtion of model proteins and gold nanoparticles. Our observations indicate densely-populated responsive amphiphilic polymers are very efficient in suppressing protein adsorption. In addition, we have established that the length of poly(ethylene glycol) spacers attached to a parent homopolymer brush is a key factor governing uptake of gold nanoparticles. Both grafting density and molecular weight of the coating are important in controlling the kinetics and thermodynamics of protein adsorption on surfaces. Our findings and methodologies can lead to the development of next generation environmentally friendly antifouling surfaces and will find application in medical devices, antifouling coatings and anti reflection finishes.

Effectiveness of Autologous Fat Grafting in Adherent Scars: Results Obtained by a Comprehensive Scar Evaluation Protocol.

PubMed

Jaspers, Mariëlle E H; Brouwer, Katrien M; van Trier, Antoine J M; Groot, Marloes L; Middelkoop, Esther; van Zuijlen, Paul P M

2017-01-01

Nowadays, patients normally survive severe traumas such as burn injuries and necrotizing fasciitis. Large skin defects can be closed but the scars remain. Scars may become adherent to underlying structures when the subcutical fat layer is damaged. Autologous fat grafting provides the possibility of reconstructing a functional sliding layer underneath the scar. Autologous fat grafting is becoming increasingly popular for scar treatment, although large studies using validated evaluation tools are lacking. The authors therefore objectified the effectiveness of single-treatment autologous fat grafting on scar pliability using validated scar measurement tools. Forty patients with adherent scars receiving single-treatment autologous fat grafting were measured preoperatively and at 3-month follow-up. The primary outcome parameter was scar pliability, measured using the Cutometer. Scar quality was also evaluated by the Patient and Observer Scar Assessment Scale and the DSM II ColorMeter. To prevent selection bias, measurements were performed following a standardized algorithm. The Cutometer parameters elasticity and maximal extension improved 22.5 percent (p < 0.001) and 15.6 percent (p = 0.001), respectively. Total Patient and Observer Scar Assessment Scale scores improved from 3.6 to 2.9 on the observer scale, and from 5.1 to 3.8 on the patient scale (both p < 0.001). Color differences between the scar and normal skin remained unaltered. For the first time, the effect of autologous fat grafting on functional scar parameters was ascertained using a comprehensive scar evaluation protocol. The improved scar pliability supports the authors' hypothesis that the function of the subcutis can be restored to a certain extent by single-treatment autologous fat grafting. Therapeutic, IV.

Crystalloid flush with backward unclamping may decrease post-reperfusion cardiac arrest and improve short-term graft function when compared to portal blood flush with forward unclamping during liver transplantation.

PubMed

Fukazawa, Kyota; Nishida, Seigo; Hibi, Taizo; Pretto, Ernesto A

2013-01-01

During liver transplant (LT), the release of vasoactive substances into the systemic circulation is associated with severe hemodynamic instability that is injurious to the recipient and/or the post-ischemic graft. Crystalloid flush with backward unclamping (CB) and portal blood flush with forward unclamping (PF) are two reperfusion methods to reduce reperfusion-related cardiovascular perturbations in our center. The primary aim of this study was to compare these two methods. After institutional review board (IRB) approval, cadaveric whole LT cases performed between 2003 and 2008 were reviewed. Patients were divided into two groups based on reperfusion methods: CB or PF. After background matching with propensity score, the effect of each method on post-operative graft function was assessed in detail. In our cohort of 478 patients, CB was used in 313 grafts and PF in 165. Thirty-day graft survival was lower, and risk of retransplantation was higher in PF. Multivariable model showed that CB is an independent factor to reduce primary non-function, cardiac arrest and improve 30-d graft survival. Also, the incidence of ischemic-type biliary lesions was significantly higher in the PF group. Reperfusion methods affect intraoperative hemodynamics and post-transplant outcome. CB allows for control over temperature and composition of the perfusate, perfusion pressure, and the rate of infusion. © 2013 John Wiley & Sons A/S.

Structural and magnetic characterization of copper sulfonated phthalocyanine grafted onto treated polyethylene

NASA Astrophysics Data System (ADS)

Reznickova, A.; Kolska, Z.; Orendac, M.; Cizmar, E.; Sajdl, P.; Svorcik, V.

2016-08-01

This study focuses on high density polyethylene (HDPE) activated by Ar plasma treatment, subsequently grafted with copper sulfonated phthalocyanine (CuPc) especially pointing out to the surface and magnetic properties of those composites. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, zeta potential and by electron spin resonance (ESR). XPS analysis confirmed the successful grafting of phthalocyanine. The highest absorption was found for the sample grafted with bCuPc for 1 h. Electrokinetic analysis also confirmed the plasma treatment and also subsequent CuPc grafting influence significantly the surface chemistry and charge. These results correspond well with XPS determination. ESR studies confirmed the presence of CuPc grafted on HDPE. It was found, that grafting is mediated by magnetically inactive functional groups, rather than radicals. Magnetic properties of CuPc do not seem to change significantly after grafting CuPc on polyethylene surface.

Satisfactory knee function after single-stage posterolateral corner reconstruction in the multi-ligament injured/dislocated knee using the anatomic single-graft technique.

PubMed

Sanders, Thomas L; Johnson, Nick R; Pareek, Ayoosh; Krych, Aaron J; Marx, Robert G; Stuart, Michael J; Levy, Bruce A

2018-04-01

Increasing importance has been placed on the posterolateral corner (PLC) in maintaining varus and rotational stability of the knee. The goal of this study was to evaluate knee function and clinical stability following a single-graft PLC reconstruction technique and identify factors associated with poor knee function. This study identified patients with a multi-ligament knee injury between 2006 and 2013. Patients who received a single-graft fibular collateral ligament and PLC reconstruction with a single-stage surgery during the study period and had a minimum follow-up of 2 years after surgery were included. Functional outcomes were assessed using Lysholm and IKDC scores. Varus and rotational knee laxity and range of motion were assessed using physical examination. The final study cohort included 61 patients who underwent PLC reconstruction using a single-graft technique. The mean IKDC score was 74.1 (± 22.3) and the mean Lysholm score was 80.3 (± 21.8) at mean follow-up of 3.8 years (range 2-9 years). Mean range of motion at final follow-up measured from 0° to 126° [range flexion: 95-145, range extension: 0-5]. Fifty-eight patients (95%) had grade 0 varus laxity in full knee extension, and 54 patients (88.5%) had grade 0 varus laxity at 30° of knee flexion. Female gender was associated with a lower postoperative IKDC score (p = 0.04). Surgical treatment of the PLC using a single-graft technique can result in satisfactory knee function and stable physical examination findings at minimum 2 years after surgery. Female gender was predictive of poor knee function after PLC reconstruction. Surgical treatment of PLC injuries should be individualized based on the timing of surgery, specific injured knee structures, and physical examination findings. This study helps validate the use of a single-graft technique for PLC reconstruction and can be used to help counsel patients about expected knee function after surgical treatment of PLC injuries. Level of evidence IV.

A theoretical study for electronic and transport properties of covalent functionalized MoS2 monolayer

NASA Astrophysics Data System (ADS)

Gao, Lijuan; Yang, Zhao-Di; Zhang, Guiling

2017-06-01

The geometries, electronic and electron transport properties of a series of functionalized MoS2 monolayers were investigated using density-functional theory (DFT) and the non-equilibrium Green's function (NEGF) methods. n-Propyl, n-trisilicyl, phenyl, p-nitrophenyl and p-methoxyphenyl are chosen as electron-donating groups. The results show covalent functionalization with electron-donating groups could make a transformation from typical semiconducting to metallic properties for appearance of midgap level across the Fermi level (Ef). The calculations of transport properties for two-probe devices indicate that conductivities of functionalized systems are obviously enhanced relative to pristine MoS2 monolayer. Grafted groups contribute to the major transport path and play an important role in enhancing conductivity. The NDR effect is found. The influence of grafted density is also studied. Larger grafted density leads to wider bandwidth of midgap level, larger current response of I-V curves and larger current difference between peak and valley.

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. © 2016 American Association for the Study of Liver Diseases.

Local vs. systemic administration of bisphosphonates in rat cleft bone graft: A comparative study

PubMed Central

Lin, Lawrence; Olson, Jeffrey; Kwon, Taewoo; Bezouglaia, Olga; Tran, Jaime; Hoang, Michael; Bui, Kimberly; Kim, Reuben H.; Tetradis, Sotirios

2018-01-01

A majority of patients with orofacial cleft deformity requires cleft repair through a bone graft. However, elevated amount of bone resorption and subsequent bone graft failure remains a significant clinical challenge. Bisphosphonates (BPs), a class of anti-resorptive drugs, may offer great promise in enhancing the clinical success of bone grafting. In this study, we compared the effects of systemic and local delivery of BPs in an intraoral bone graft model in rats. We randomly divided 34 female 20-week-old Fischer F344 Inbred rats into four groups to repair an intraoral critical-sized defect (CSD): (1) Control: CSD without graft (n = 4); (2) Graft/Saline: bone graft with systemic administration of saline 1 week post-operatively (n = 10); (3) Graft/Systemic: bone graft with systemic administration of zoledronic acid 1 week post-operatively (n = 10); and (4) Graft/Local: bone graft pre-treated with zoledronic acid (n = 10). At 6-weeks post-operatively, microCT volumetric analysis showed a significant increase in bone fraction volume (BV/TV) in the Graft/Systemic (62.99 ±14.31%) and Graft/Local (69.35 ±13.18%) groups compared to the Graft/Saline (39.18±10.18%). Similarly, histological analysis demonstrated a significant increase in bone volume in the Graft/Systemic (78.76 ±18.00%) and Graft/Local (89.95 ±4.93%) groups compared to the Graft/Saline (19.74±18.89%). The local delivery approach resulted in the clinical success of bone grafts, with reduced graft resorption and enhanced osteogenesis and bony integration with defect margins while avoiding the effects of BPs on peripheral osteoclastic function. In addition, local delivery of BPs may be superior to systemic delivery with its ease of procedure as it involves simple soaking of bone graft materials in BP solution prior to graft placement into the defect. This new approach may provide convenient and promising clinical applications towards effectively managing cleft patients. PMID:29304080

The Influence of Task Complexity on Knee Joint Kinetics Following ACL Reconstruction

PubMed Central

Schroeder, Megan J.; Krishnan, Chandramouli; Dhaher, Yasin Y.

2015-01-01

Background Previous research indicates that subjects with anterior cruciate ligament reconstruction exhibit abnormal knee joint movement patterns during functional activities like walking. While the sagittal plane mechanics have been studied extensively, less is known about the secondary planes, specifically with regard to more demanding tasks. This study explored the influence of task complexity on functional joint mechanics in the context of graft-specific surgeries. Methods In 25 participants (10 hamstring tendon graft, 6 patellar tendon graft, 9 matched controls), three-dimensional joint torques were calculated using a standard inverse dynamics approach during level walking and stair descent. The stair descent task was separated into two functionally different sub-tasks—step-to-floor and step-to-step. The differences in external knee moment profiles were compared between groups; paired differences between the reconstructed and non-reconstructed knees were also assessed. Findings The reconstructed knees, irrespective of graft type, typically exhibited significantly lower peak knee flexion moments compared to control knees during stair descent, with the differences more pronounced in the step-to-step task. Frontal plane adduction torque deficits were graft-specific and limited to the hamstring tendon knees during the step-to-step task. Internal rotation torque deficits were also primarily limited to the hamstring tendon graft group during stair descent. Collectively, these results suggest that task complexity was a primary driver of differences in joint mechanics between anterior cruciate ligament reconstructed individuals and controls, and such differences were more pronounced in individuals with hamstring tendon grafts. Interpretation The mechanical environment experienced in the cartilage during repetitive, cyclical tasks such as walking and other activities of daily living has been argued to contribute to the development of degenerative changes to the joint and ultimately osteoarthritis. Given the task-specific and graft-specific differences in joint mechanics detected in this study, care should be taken during the rehabilitation process to mitigate these changes. PMID:26101055

Triple-Layer Vascular Grafts Fabricated by Combined E-Jet 3D Printing and Electrospinning.

PubMed

Huang, Ruiying; Gao, Xiangkai; Wang, Jian; Chen, Haoxiang; Tong, Chunyi; Tan, Yongjun; Tan, Zhikai

2018-05-29

Small-diameter tissue-engineered vascular grafts are urgently needed for clinic arterial substitute. To simulate the structures and functions of natural blood vessels, we designed a novel triple-layer poly(ε-caprolactone) (PCL) fibrous vascular graft by combining E-jet 3D printing and electrospinning techniques. The resultant vascular graft consisted of an interior layer comprising 3D-printed highly aligned strong fibers, a middle layer made by electrospun densely fibers, and an exterior structure composed of mixed fibers fabricated by co-electrospraying. The biocompatible triple-layer graft was used for in vivo implantation, and results demonstrated that the longitudinally-aligned fibers within the lumen of the graft could enhance the proliferation and migration of endothelial cells, while maintained good mechanical properties. The exterior layer provided a pathway that encouraged cells to migrate into the scaffold after implantation. This experimental graft overcame the limitations of conventionally electrospun vascular grafts of inadequate porosity and lowly cell penetration. The unique structure of the triple-layer vascular graft promoted cell growth and infiltration in vivo, thus provided an encouraging substitute for in situ tissue engineering.

Characterization and Applications of Kaolinite Robustly Grafted by an Ionic Liquid with Naphthyl Functionality

PubMed Central

Detellier, Christian

2017-01-01

Functionalization of the kaolinite (K) interlayer space is challenging. In this work, a new kaolinite-based nanohybridmaterial (K-NI) was successfully synthesized by grafting on the interlayer aluminol surfaces the ionic liquid, 1-(1-methylnaphthyl)-3-(2-hydroxyethyl) imidazolium chloride (NI), using a guest displacement strategy. A substantial increase of the basal spacing (10.8 Å) was obtained. This is a grafted derivative of kaolinite possessing one of the largest d-values. Washing in water for several days and other vigorous treatments such as sonication showed a minor effect on the integrity of the material. FTIR and 13C NMR confirmed the conservation of the structure of the ionic liquid after the grafting. Thermal analysis confirmed the presence of grafted material and was used to estimate the abundance of the grafted ionic liquid (0.44 mole per mole of kaolinite structural formula, (Al2Si2O5(OH)4)). By using cyclic voltammetry, the permeability of a film of K-NI for the bulky ferricyanide ions was demonstrated. The accumulation of nitrophenolate anions was effective (maximum capacity of 190 μmol/g), but was less important than what was expected due to the steric hindrance of the bulky grafted NI. Although the presence of chloride anions reduced the adsorption capacity, the affinity of the modified kaolinite interlayer space for the nitrophenolate anions was demonstrated. PMID:28850087

Characterization and Applications of Kaolinite Robustly Grafted by an Ionic Liquid with Naphthyl Functionality.

PubMed

Kenne Dedzo, Gustave; Detellier, Christian

2017-08-29

Functionalization of the kaolinite (K) interlayer space is challenging. In this work, a new kaolinite-based nanohybridmaterial (K-NI) was successfully synthesized by grafting on the interlayer aluminol surfaces the ionic liquid, 1-(1-methylnaphthyl)-3-(2-hydroxyethyl) imidazolium chloride (NI), using a guest displacement strategy. A substantial increase of the basal spacing (10.8 Å) was obtained. This is a grafted derivative of kaolinite possessing one of the largest d -values. Washing in water for several days and other vigorous treatments such as sonication showed a minor effect on the integrity of the material. FTIR and 13 C NMR confirmed the conservation of the structure of the ionic liquid after the grafting. Thermal analysis confirmed the presence of grafted material and was used to estimate the abundance of the grafted ionic liquid (0.44 mole per mole of kaolinite structural formula, (Al₂Si₂O₅(OH)₄)). By using cyclic voltammetry, the permeability of a film of K-NI for the bulky ferricyanide ions was demonstrated. The accumulation of nitrophenolate anions was effective (maximum capacity of 190 μmol/g), but was less important than what was expected due to the steric hindrance of the bulky grafted NI. Although the presence of chloride anions reduced the adsorption capacity, the affinity of the modified kaolinite interlayer space for the nitrophenolate anions was demonstrated.

Rescue from dwarfism by thyroid function compensation in rdw rats.

PubMed

Furudate, Sen-ichi; Ono, Masao; Shibayama, Keiko; Ohyama, Yoshihide; Kuwada, Masahiro; Kimura, Toshimi; Kameya, Toru

2005-10-01

The rdw rat was initially reported as having hereditary dwarfism caused by pituitary dysfunction. Subsequent studies on the rdw rat, however, have demonstrated that the primary cause of rdw dwarfism is present in the thyroid gland but not in the pituitary gland. The primary cause of rdw rat disorders is a missense mutation of the thyroglobulin (Tg) gene by a one-point mutation. In the present study, we attempted to rescue the dwarfism of the rdw rats using a diet supplemented with thyroid powder (T-powder) and a thyroid graft (T-graft). The infants of the rdw rat were successfully raised to a mature stage body weight, accompanied by elevation of serum growth hormone (GH) and prolactin (PRL), by the T-powder. Furthermore, the T-graft successfully increased the body weight with fertility. The serum GH and PRL levels in the T-graft rdw rat significantly increased. The serum thyroid-stimulating hormone (TSH) levels in the T-graft rdw rat were significantly decreased but were significantly higher than those in the control rat. The GH and PRL mRNA expression in the rdw rat with the T-graft was virtually the same as that of the control, but the TSH beta mRNA differed from that of the control rats. Thus, the dwarfism in the rdw rat is rescued by thyroid function compensation, such as that afforded by T-powder and T-graft.

The role of environmental factors in regulating the development of cartilaginous grafts engineered using osteoarthritic human infrapatellar fat pad-derived stem cells.

PubMed

Liu, Yurong; Buckley, Conor T; Downey, Richard; Mulhall, Kevin J; Kelly, Daniel J

2012-08-01

Engineering functional cartilaginous grafts using stem cells isolated from osteoarthritic human tissue is of fundamental importance if autologous tissue engineering strategies are to be used in the treatment of diseased articular cartilage. It has previously been demonstrated that human infrapatellar fat pad (IFP)-derived stem cells undergo chondrogenesis in pellet culture; however, the ability of such cells to generate functional cartilaginous grafts has not been adequately addressed. The objective of this study was to explore how environmental conditions regulate the functional development of cartilaginous constructs engineered using diseased human IFP-derived stem cells (FPSCs). FPSCs were observed to display a diminished chondrogenic potential upon encapsulation in a three-dimensional hydrogel compared with pellet culture, synthesizing significantly lower levels of glycosaminoglycan and collagen on a per cell basis. To engineer more functional cartilaginous grafts, we next explored whether additional biochemical and biophysical stimulations would enhance chondrogenesis within the hydrogels. Serum stimulation was observed to partially recover the diminished chondrogenic potential within hydrogel culture. Over 42 days, stem cells that had first been expanded in a low-oxygen environment proliferated extensively on the outer surface of the hydrogel in response to serum stimulation, assembling a dense type II collagen-positive cartilaginous tissue resembling that formed in pellet culture. The application of hydrostatic pressure did not further enhance extracellular matrix synthesis within the hydrogels, but did appear to alter the spatial accumulation of extracellular matrix leading to the formation of a more compact tissue with superior mechanically functionality. Further work is required in order to recapitulate the environmental conditions present during pellet culture within scaffolds or hydrogels in order to engineer more functional cartilaginous grafts using human osteoarthritic FPSCs.

Tailored dialysis start may allow persistence of residual renal function after graft failure: a case report.

PubMed

Piccoli, G B; Motta, D; Gai, M; Mezza, E; Maddalena, E; Bravin, M; Tattoli, F; Consiglio, V; Burdese, M; Bilucaglia, D; Ferrari, A; Segoloni, G P

2004-11-01

Restarting dialysis after kidney transplantation is a critical step with psychological and clinical implications. Maintenance of residual renal function a known factor affecting survival in chronic kidney disease, has so far not been investigated after a kidney transplantation. A 54-year-old woman who started dialysis in 1974 (first graft, 1975-1999) received a second "marginal" kidney graft in February 2001 (donor age, 65 years). Her chronic therapy was tacrolimus and steroids. She had a clinical history as follows: nadir creatinine level of 1.5 mg/dL, moderate-severe hypertension, progressive graft dysfunction, nonresponsiveness to addition of mycophenolate, tapering FK levels, and a rescue switch from tacrolimus to rapamycin. From October to December 2003, the creatinine level increased from 2-2.8 to 7 mg/dL. Biopsy specimen showed malignant and "benign" nephrosclerosis, posttransplantation glomerulopathy, and tacrolimus toxicity. Chronic dialysis was started (GFR <3 mL/min). Rapamycin was discontinued. Dialysis was tailored to reach an equivalent renal clearance of >15 mL/min (2 sessions/wk). Blood pressure control improved, nephrotoxic drugs were avoided, and fluid loss was minimized (maximum 500 mL/hr). By this policy, renal function progressively increased to GFR >10 mL/min in May 2004, allowing a once or twice weekly dialysis schedule, with good clinical balance, and obvious advantages for the quality of life. This long-term patient, who restarted dialysis with severely reduced renal function, regained sufficient renal function to allow once weekly dialysis. Thus, careful tailoring of dialysis sessions at the restart of dialysis may allow preservation of residual kidney function, at least in individuals for whom a subsequent graft is unlikely.

Age and Early Graft Function Relate With Risk-Benefit Ratio of Allogenic Islet Transplantation Under Antithymocyte Globulin-Mycophenolate Mofetil-Tacrolimus Immune Suppression.

PubMed

Lee, DaHae; Keymeulen, Bart; Hilbrands, Robert; Ling, Zhidong; Van de Velde, Ursule; Jacobs-Tulleneers-Thevissen, Daniel; Maleux, Geert; Lapauw, Bruno; Crenier, Laurent; De Block, Christophe; Mathieu, Chantal; Pipeleers, Daniel; Gillard, Pieter

2017-09-01

Induction therapy with a T cell-depleting agent followed by mycophenolate mofetil and tacrolimus is presently the most frequently used immune suppression (IS) regimen in islet transplantation. This study assesses its safety and tolerability in nonuremic type 1 diabetic recipients. Fifty-one patients (age, between 29 and 63 years) with high glycemic variability and problematic hypoglycemia received intraportal islet grafts under anti-thymocyte globulin-mycophenolate mofetil-tacrolimus protocol. They were followed up for over 48 months for function of the implant and adverse events. Severe hypoglycemia and diabetic ketoacidosis were absent in patients with functioning graft. Immune suppressive therapy was maintained for 48 months in 29 recipients with sustained function (group A), whereas 16 patients stopped earlier due to graft failure (group B) and in 6 for other reasons. Group A was significantly older at the time of implantation and achieved higher graft function at posttransplantation month 6 under similar dose of IS. Prevalence of IS-related side effects was similar in groups A and B, occurring predominantly during the first year posttransplantation. IS-related serious adverse events (SAE) were reported in 47% of patients, with 4 presenting with cytomegalovirus infection and 4 (age, 42-59 years) diagnosed with cancer. Except in 1 patient with cancer, all SAEs resolved after appropriate treatment. These risk/benefit data serve as a basis for clinical decision-making before entering an intraportal islet transplantation protocol. A longer benefit is observed in recipients of higher age (≥40 years), but it is not associated with more side effects and SAE.

Outer Electrospun Polycaprolactone Shell Induces Massive Foreign Body Reaction and Impairs Axonal Regeneration through 3D Multichannel Chitosan Nerve Guides

PubMed Central

Behrens, Peter; Wienecke, Soenke; Chakradeo, Tanmay; Glasmacher, Birgit

2014-01-01

We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts. PMID:24818158

Outer electrospun polycaprolactone shell induces massive foreign body reaction and impairs axonal regeneration through 3D multichannel chitosan nerve guides.

PubMed

Duda, Sven; Dreyer, Lutz; Behrens, Peter; Wienecke, Soenke; Chakradeo, Tanmay; Glasmacher, Birgit; Haastert-Talini, Kirsten

2014-01-01

We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts.

Safe use of liver grafts from hepatitis B surface antigen positive donors in liver transplantation.

PubMed

Yu, Songfeng; Yu, Jun; Zhang, Wei; Cheng, Longyu; Ye, Yufu; Geng, Lei; Yu, Zhiyong; Yan, Sheng; Wu, Lihua; Wang, Weilin; Zheng, Shusen

2014-10-01

Liver grafts from hepatitis B surface antigen (HBsAg) positive donors could have potential to increase the donor pool. However, knowledge is extremely limited in this setting because currently available data are mostly from case reports. We aimed to assess the outcomes and experiences of liver transplantation from HBsAg positive donors in a single centre study. From January 2010 to February 2013, 42 adult patients underwent liver transplantation from HBsAg positive donors and 327 patients from HBsAg negative ones. The outcomes including complications and survival of two groups were compared and antiviral therapy retrospectively reviewed. HBsAg positive liver grafts were more likely to be allocated to patients with hepatitis B (HBV)-related diseases. Post-transplant evaluation showed similar graft function regaining pace and no differences in complications such as primary non-function, acute rejection and biliary complications. Patient and graft survivals were comparable to that of HBsAg negative grafts. Furthermore, HBsAg persisted after transplant in all patients that received positive grafts. The donor HBV serum status determined the one of the recipient after transplantation. No HBV flare-ups were observed under antiviral therapy of oral nucleotide analogues, regardless of using hepatitis B immunoglobulin combination. Utilization of HBsAg positive liver grafts seems not to increase postoperative morbidity and mortality. Therefore it is a safe way to expand the donor pool when no suitable donor is available. Our experience also suggests that hepatitis B immunoglobulin should be abandoned in recipients of HBsAg positive liver grafts, in whom HBV prophylaxis could be the only oral antiviral therapy. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Characterization of dextran-grafted hydrophobic charge-induction resins: Structural properties, protein adsorption and transport.

PubMed

Liu, Tao; Angelo, James M; Lin, Dong-Qiang; Lenhoff, Abraham M; Yao, Shan-Jing

2017-09-29

The structural and functional properties of a series of dextran-grafted and non-grafted hydrophobic charge-induction chromatographic (HCIC) agarose resins were characterized by macroscopic and microscopic techniques. The effects of dextran grafting and mobile phase conditions on the pore dimensions of the resins were investigated with inverse size exclusion chromatography (ISEC). A significantly lower pore radius (17.6nm) was found for dextran-grafted than non-grafted resins (29.5nm), but increased salt concentration would narrow the gap between the respective pore radii. Two proteins, human immunoglobulin G (hIgG) and bovine serum albumin (BSA), were used to examine the effect of protein characteristics. The results of adsorption isotherms showed that the dextran-grafted resin with high ligand density had substantially higher adsorption capacity and enhanced the salt-tolerance property for hIgG, but displayed a significantly smaller benefit for BSA adsorption. Confocal laser scanning microscopy (CLSM) showed that hIgG presented more diffuse and slower moving adsorption front compared to BSA during uptake into the resins because of the selective binding of multiple species from polyclonal IgG; polymer-grafting with high ligand density could enhance the rate of hIgG transport in the dextran-grafted resins without salt addition, but not for the case with high salt and BSA. The results indicate that microscopic analysis using ISEC and CLSM is useful to improve the mechanistic understanding of resin structure and of critical functional parameters involving protein adsorption and transport, which would guide the rational design of new resins and processes. Copyright © 2017. Published by Elsevier B.V.

IL-25 promotes the function of CD4+CD25+ T regulatory cells and prolongs skin-graft survival in murine models.

PubMed

Tang, Jiayou; Zhou, Xiaohui; Liu, Jie; Meng, Qingshu; Han, Yang; Wang, Zhulin; Fan, Huimin; Liu, Zhongmin

2015-10-01

Interleukin (IL)-25, also known as IL-17E, belongs to the IL-17 family of cytokines. Unlike other IL-17 family members, IL-25 promotes Th2-type immune responses, stimulating IL-4, IL-5, and IL-13 production. Here, we employed murine models of skin graft to explore the role of IL-25 in suppression of graft rejection. We found that IL-25 expression is increased during allograft rejection, and allograft rejection was enhanced in IL-25 KO mice. IL-25 KO was associated with down-regulation of Foxp3 expression in CD4+ T cells. Further, while adoptive transfer of WT regulatory T cells (Tregs) protected against allograft rejection, adoptive transfer of IL-25 deficient Tregs failed to protect against allograft rejection. Exogenous IL-25 restored Foxp3 expression and Treg function in vitro. Moreover, IL-25 promoted phosphorylation of NFAT2. Thus, IL-25 may enhance Treg function by up-regulating NFAT2 phosphorylation. Our findings suggest that IL-25 can sustain Foxp3 expression, enhance the suppressive function of Tregs, and prolong skin-graft survival. Copyright © 2015 Elsevier B.V. All rights reserved.

Poly(vinyl alcohol) stabilization of acrylic emulsion polymers using the miniemulsion approach

NASA Astrophysics Data System (ADS)

Kim, Noma

Miniemulsion approach was employed to obtain stable acrylic latexes of n-butyl acrylate and methyl methacrylate (50/50 wt%) stabilized with poly(vinyl alcohol) (PVA) and to enhance the grafting reaction between PVA and acrylic monomers at the water/droplet interface. The stability of miniemulsions were studied in terms of the type and concentration of' the stabilizer, and the PVA partitioning were determined as a function of the PVA concentration. Using the comparison of PVA partitioning at droplet surface and grafted PVA as a function of concentration, it was suggested that the water/monomer interface is the main grafting site in the miniemulsion polymerization. Seeded emulsion and miniemulsion copolymerizations initiated with water-soluble (hydrogen peroxide, HPO), partially water-soluble (t-butyl peroxide, TBHP), and oil-soluble (t-butyl peroxyoctoate, TBPO) initiators were carried out to further investigate the oil/water interface as the grafting site for PVA. The interaction between the capillary wall in the CHDF (capillary hydrodynamic fractionation) chromatographic particle sizer and the water-soluble polymers adsorbed on the particle surface was studied using different types of water-soluble polymers and eluants. Different grafting architectures depending on the initiation site were suggested based on the CHDF results. The amounts of grafted PVA produced in miniemulsion polymers initiated with TBHP and TBPO were substantially less than those in the corresponding seeded emulsion polymerizations. The effect on the internal viscosity at the interface was proposed to explain the difference in grafting in terms of polymerization methods. Aqueous phase and interface grafting were studied using the measurement of the degree of hydrolysis (DH) of the serum PVA and adsorbed PVA after miniemulsion polymerizations. Based on the results, it was found that aqueous phase and interface grafting occurred in the HPO system; however, interface grafting dominated the TBHP system. Colloidal instability in conventional emulsion polymerizations was investigated and compared with the corresponding miniemulsion polymerization. It was found that the grafted PVA in conventional emulsion polymerizations was more hydrophobic presumably due to a greater amount of grafted chains than that in similar miniemulsion polymerizations and this could be correlated with the colloidal instability during conventional emulsion polymerizations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobayashi, Takeshi; Singappuli-Arachchige, Dilini; Wang, Zhuoran

Solid-state NMR spectroscopy, both conventional and dynamic nuclear polarization (DNP)-enhanced, was employed to study the spatial distribution of organic functional groups attached to the surface of mesoporous silica nanoparticles via co-condensation and grafting. The most revealing information was provided by DNP-enhanced two-dimensional 29Si– 29Si correlation measurements, which unambiguously showed that post-synthesis grafting leads to a more homogeneous dispersion of propyl and mercaptopropyl functionalities than co-condensation. Furthermore, during the anhydrous grafting process, the organosilane precursors do not self-condense and are unlikely to bond to the silica surface in close proximity (less than 4 Å) due to the limited availability of suitablymore » arranged hydroxyl groups.« less

Computation-Guided Backbone Grafting of a Discontinuous Motif onto a Protein Scaffold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azoitei, Mihai L.; Correia, Bruno E.; Ban, Yih-En Andrew

2012-02-07

The manipulation of protein backbone structure to control interaction and function is a challenge for protein engineering. We integrated computational design with experimental selection for grafting the backbone and side chains of a two-segment HIV gp120 epitope, targeted by the cross-neutralizing antibody b12, onto an unrelated scaffold protein. The final scaffolds bound b12 with high specificity and with affinity similar to that of gp120, and crystallographic analysis of a scaffold bound to b12 revealed high structural mimicry of the gp120-b12 complex structure. The method can be generalized to design other functional proteins through backbone grafting.

[Comparison of composite grafting of autoskin with acellular dermal matrix from different sources].

PubMed

Chen, Jin-Hui; Qi, Shun-Zhen; Sun, Hui-Chen; He, Zhan-Guo; Li, Hui; Zhu, Yu-Feng; Chen, Xing

2003-10-01

To compare the composite grafts of acellular dermal matrix (ADM) from different sources with autoskin. Six local white mini pigs were employed for the experiment. The pigs were randomly divided into four groups according to different skin grafts, i.e. A (human ADM with razor thin autoskin), B (porcine ADM with razor thin autoskin), C (razor thin autoskin only), and D (split thickness autoskin) as control. The survival rate, the contraction degree of the grafts, and the histological changes in grafting area were observed at 2, 4, 8, 12 and 24 hours after the operation. The grafted area in both A and B groups appeared smooth and elastic with satisfactory graft survival. The in growth of the host reparative cells such as fibroblast and vascular endothelium could be induced by composite grafts of different ADMs with skin grafting. The contraction areas in A and B groups seemed bigger than those in C and D groups. The tissue structure of grafting areas was similar to that of split thickness skin grafting area at 24 post-operation weeks. Combination of the homogenous and heterogeneous ADMs with autografts exhibited similar biological function during the observation period (24 weeks after operation). Xenogenous ADMs might have broader clinical applications.

The viability of transplanting organs from donors who underwent cardiopulmonary resuscitation: A systematic review.

PubMed

West, Stephen; Soar, Jasmeet; Callaway, Clifton W

2016-11-01

To identify reports of patients who underwent cardiopulmonary resuscitation (CPR) prior to solid organ donation and compare recipient and organ function outcomes to those that did not undergo CPR. Donation after restoration of circulation then progressing to death and those donating with on-going CPR who would have otherwise have termination of efforts were both included. Systematic review. Clinical studies comparing the outcome of patients and organs retrieved from donors who underwent CPR with those that did not require CPR. Full-text articles were searched on EmBASE, MEDLINE, Cochrane Database of Systematic Reviews and the Cochrane Register of Controlled Trials. Twenty-two observational studies were included. There were 12,206 adult and 2552 paediatric organ transplantation identified. Comparing donation after restoration of circulation there was no difference in immediate, one year, and five-year graft function. Donation with on-going CPR was associated with reduced immediate graft function for both renal and hepatic transplantation, however long term function was not different. CPR does not appear to adversely affect graft function. Patients who have restored circulation after resuscitation and subsequently progress to death should be evaluated for organ donation. Those with on-going CPR should be considered for hepatic and renal transplantation but there may be worse initial graft function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Peritransplant Soluble CD30 as a Risk Factor for Slow Kidney Allograft Function, Early Acute Rejection, Worse Long-Term Allograft Function, and Patients' Survival.

PubMed

Trailin, Andriy V; Ostapenko, Tetyana I; Nykonenko, Tamara N; Nesterenko, Svitlana N; Nykonenko, Olexandr S

2017-01-01

We aimed to determine whether serum soluble CD30 (sCD30) could identify recipients at high risk for unfavorable early and late kidney transplant outcomes. Serum sCD30 was measured on the day of kidney transplantation and on the 4th day posttransplant. We assessed the value of these measurements in predicting delayed graft function, slow graft function (SGF), acute rejection (AR), pyelonephritis, decline of allograft function after 6 months, and graft and patient survival during 5 years of follow-up in 45 recipients. We found the association between low pretransplant serum levels of sCD30 and SGF. The absence of significant decrease of sCD30 on the 4th day posttransplant was characteristic for SGF, early AR (the 8th day-6 months), late AR (>6 months), and early pyelonephritis (the 8th day-2 months). Lower pretransplant and posttransplant sCD30 predicted worse allograft function at 6 months and 2 years, respectively. Higher pretransplant sCD30 was associated with higher frequency of early AR, and worse patients' survival, but only in the recipients of deceased-donor graft. Pretransplant sCD30 also allowed to differentiate patients with early pyelonephritis and early AR. Peritransplant sCD30 is useful in identifying patients at risk for unfavorable early and late transplant outcomes.

Spatial distribution of organic functional groups supported on mesoporous silica nanoparticles: A study by conventional and DNP-enhanced 29Si solid-state NMR

DOE PAGES

Kobayashi, Takeshi; Singappuli-Arachchige, Dilini; Wang, Zhuoran; ...

2016-12-23

Solid-state NMR spectroscopy, both conventional and dynamic nuclear polarization (DNP)-enhanced, was employed to study the spatial distribution of organic functional groups attached to the surface of mesoporous silica nanoparticles via co-condensation and grafting. The most revealing information was provided by DNP-enhanced two-dimensional 29Si– 29Si correlation measurements, which unambiguously showed that post-synthesis grafting leads to a more homogeneous dispersion of propyl and mercaptopropyl functionalities than co-condensation. Furthermore, during the anhydrous grafting process, the organosilane precursors do not self-condense and are unlikely to bond to the silica surface in close proximity (less than 4 Å) due to the limited availability of suitablymore » arranged hydroxyl groups.« less

Antioxidant multi-walled carbon nanotubes by free radical grafting of gallic acid: new materials for biomedical applications.

PubMed

Cirillo, Giuseppe; Hampel, Silke; Klingeler, Rüdiger; Puoci, Francesco; Iemma, Francesca; Curcio, Manuela; Parisi, Ortensia Ilaria; Spizzirri, Umile Gianfranco; Picci, Nevio; Leonhardt, Albrecht; Ritschel, Manfred; Büchner, Bernd

2011-02-01

To prove the possibility of covalently functionalizing multi-walled carbon nanotubes (CNTs) by free radical grafting of gallic acid on their surface with the subsequent synthesis of materials with improved biological properties evaluated by specific in-vitro assays. Antioxidant CNTs were synthesized by radical grafting of gallic acid onto pristine CNTs. The synthesis of carbon nanotubes was carried out in a fixed-bed reactor and, after the removal of the amorphous carbon, the grafting process was performed. The obtained materials were characterized by fluorescence and Fourier transform infrared spectroscopy (FT-IR) analyses. After assessment of the biocompatibility and determination of the disposable phenolic group content, the antioxidant properties were evaluated in terms of total antioxidant activity and scavenger ability against 2,2'-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl and peroxyl radicals. Finally the inhibition activity on acetylcholinesterase was evaluated.   The covalent functionalization of CNTs with gallic acid was confirmed and the amount of gallic acid bound per g of CNTs was found to be 2.1±0.2 mg. Good antioxidant and scavenging properties were recorded in the functionalized CNTs, which were found to be able to inhibit the acetylcholinesterase with potential improved activity for biomedical and pharmaceutical applications. For the first time, a free radical grafting procedure was proposed as a synthetic approach for the covalent functionalization of CNTs with an antioxidant polyphenol. © 2010 The Authors. JPP © 2010 Royal Pharmaceutical Society.

Photochemical Grafting of Organic Alkenes to Single-Crystal TiO2 Surfaces: A Mechanistic Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franking, Ryan A.; Kim, Heesuk; Chambers, Scott A.

2012-08-21

The UV-induced photochemical grafting of terminal alkenes has emerged as a versatile way to form molecular layers on semiconductor surfaces. Recent studies have shown that grafting reactions can be initiated by photoelectron emission into the reactant liquid as well as by excitation across the semiconductor bandgap, but the relative importance of these two processes is expected to depend on the nature of the semiconductor and the reactant alkene and the excitation wavelength. Here we report a study of the wavelength-dependent photochemical grafting of alkenes onto single-crystal TiO2 samples. Trifluoroacetamide-protected 10-aminododec-1-ene (TFAAD), 10-N-BOC-aminodec-1-ene (t-BOC) and 1-dodecene were used as model alkenes.more » On rutile(110), photons with energy above the bandgap but below the expected work function are not effective at inducing grafting, while photons with energy sufficient to induce electronic transitions from the TiO2 Fermi level to electronic acceptor states of the reactant molecules induce grafting. A comparison of rutile (110), rutile(001), anatase (001), and anatase(101) samples shows slightly enhanced grafting for rutile but no difference between crystal faces for a given crystal phase. Hydroxylation of the surface increases the reaction rate by lowering the work function and thereby facilitating photoelectron ejection into the adjacent alkene. These results demonstrate that photoelectron emission is the dominant mechanism responsible for grafting when using short-wavelength (~254 nm) light and suggest that photoemission events beginning on mid-gap states may play a crucial role.« less

[Kidney transplantation: consecutive one thousand transplants at National Institute of Medical Sciences and Nutrition Salvador Zubirán in Mexico City].

PubMed

Marino-Vazquez, Lluvia Aurora; Sánchez-Ugarte, Regina; Morales-Buenrostro, Luis Eduardo

2011-09-01

The National Institute of Medical Sciences and Nutrition Salvador Zubiran (INCMNSZ) is a specialty hospital for adults and a teaching hospital, which performed the first kidney transplant in 1967; in 1971 it began the formal program of renal transplantation. Recently, it was performed the kidney transplant number 1000, so this article presents the information of these thousand kidney transplants, with special emphasis on survival. Retrospective cohort study which included 1000 consecutive transplants performed at the INCMNSZ between 1967 and June 2011. It describes the general characteristics of kidney transplant recipients, transplant-related variables, initial immunosuppression and complications. Descriptive statistics were used. The survival analysis was performed using the Kaplan-Meier method. It shows the patient survival, graft survival censored for death with functional graft and total graft survival (uncensored). Patient survival at 1, 3, 5, 10, 15, and 20 years was 94.9, 89.6, 86.8, 76.9, 66.1, and 62.2%, respectively. Graft survival censored for death with functional graft at 1, 3, 5, 10, 15, and 20 years was 93.1, 87.1, 83.5, 73.9, 62.7, and 52.5% respectively. Risk factors associated with poorer graft survival were younger age of the recipient, transplant during the first period (1967-1983), and a HLA mismatch. Patient and graft survival have improved over time through the use of better immunosuppression and use of induction therapy. Identification of risk factors affecting graft survival, allows each center to set their strategies to improve the patient's outcome.

Efficient fabrication of high-capacity immobilized metal ion affinity chromatographic media: The role of the dextran-grafting process and its manipulation.

PubMed

Zhao, Lan; Zhang, Jingfei; Huang, Yongdong; Li, Qiang; Zhang, Rongyue; Zhu, Kai; Suo, Jia; Su, Zhiguo; Zhang, Zhigang; Ma, Guanghui

2016-03-01

Novel high-capacity Ni(2+) immobilized metal ion affinity chromatographic media were prepared through the dextran-grafting process. Dextran was grafted to an allyl-activated agarose-based matrix followed by functionalization for the immobilized metal ion affinity chromatographic media. With elaborate regulation of the allylation degree, dextran was completely or partly grafted to agarose microspheres, namely, completely dextran-grafted agarose microspheres and partly dextran-grafted ones, respectively. Confocal laser scanning microscope results demonstrated that a good adjustment of dextran-grafting degree was achieved, and dextran was distributed uniformly in whole completely dextran-grafted microspheres, while just distributed around the outside of the partly dextran-grafted ones. Flow hydrodynamic properties were improved greatly after the dextran-grafting process, and the flow velocity increased by about 30% compared with that of a commercial chromatographic medium (Ni Sepharose FF). A significant improvement of protein binding performance was also achieved by the dextran-grafting process, and partly dextran-grafted Ni(2+) chelating medium had a maximum binding capacity for His-tagged lactate dehydrogenase about 2.5 times higher than that of Ni Sepharose FF. The results indicated that this novel chromatographic medium is promising for applications in high-efficiency and large-scale protein purification. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanostructured bio-functional polymer brushes.

PubMed

Padeste, Celestino; Farquet, Patrick; Potzner, Christian; Solak, Harun H

2006-01-01

Structured poly(glycidyl methracrylate) (poly-GMA) brushes have been grafted onto flexible fluoro-polymer films using a radiation grafting process. The reactive epoxide of poly-GMA provides the basis for a versatile biofunctionalization of the grafted brushes. Structure definition by extreme ultraviolet (EUV) exposure allowed nanometer-scale resolution of periodic patterns. By variation of the exposure dose the height of the grafted structures can be adapted in a wide range. Derivatization of the grafted brushes included reaction with various amines with different side chains, hydrolysis of the epoxide to diols to increase protein resistance and introduction of ionic groups to yield poly-electrolytes. As an example for biofunctionalization, biotin was linked to the grafted brush and biofunctionality was demonstrated in a competitive biotin-streptavidin assay. In this article we also present a brief review of other approaches to obtain structured biofunctional polymer brushes.

Effects of Dopamine Donor Pretreatment on Graft Survival after Kidney Transplantation: A Randomized Trial.

PubMed

Schnuelle, Peter; Schmitt, Wilhelm H; Weiss, Christel; Habicht, Antje; Renders, Lutz; Zeier, Martin; Drüschler, Felix; Heller, Katharina; Pisarski, Przemyslaw; Banas, Bernhard; Krämer, Bernhard K; Jung, Matthias; Lopau, Kai; Olbricht, Christoph J; Weihprecht, Horst; Schenker, Peter; De Fijter, Johan W; Yard, Benito A; Benck, Urs

2017-03-07

Donor dopamine improves initial graft function after kidney transplantation due to antioxidant properties. We investigated if a 4 µ g/kg per minute continuous dopamine infusion administered after brain-death confirmation affects long-term graft survival and examined the exposure-response relationship with treatment duration. Five-year follow-up of 487 renal transplant patients from 60 European centers who had participated in the randomized, multicenter trial of dopamine donor pretreatment between 2004 and 2007 (ClinicalTrials.gov identifier: NCT00115115). Follow-up was complete in 99.2%. Graft survival was 72.6% versus 68.7% ( P =0.34), and 83.3% versus 80.4% ( P =0.42) after death-censoring in treatment and control arms according to trial assignment. Although infusion times varied substantially in the treatment arm (range 0-32.2 hours), duration of the dopamine infusion and all-cause graft failure exhibited an exposure-response relationship (hazard ratio, 0.96; 95% confidence interval [95% CI], 0.92 to 1.00, per hour). Cumulative frequency curves of graft survival and exposure time of the dopamine infusion indicated a maximum response rate at 7.10 hours (95% CI, 6.99 to 7.21), which almost coincided with the optimum infusion time for improvement of early graft function (7.05 hours; 95% CI, 6.92 to 7.18). Taking infusion time of 7.1 hours as threshold in subsequent graft survival analyses indicated a relevant benefit: Overall, 81.5% versus 68.5%; P =0.03; and 90.3% versus 80.2%; P =0.04 after death-censoring. We failed to show a significant graft survival advantage on intention-to-treat. Dopamine infusion time was very short in a considerable number of donors assigned to treatment. Our finding of a significant, nonlinear exposure-response relationship disclosed a threshold value of the dopamine infusion time that may improve long-term kidney graft survival. Copyright © 2017 by the American Society of Nephrology.

Biofabricated film with enzymatic and redox-capacitor functionalities to harvest and store electrons.

PubMed

Liba, Benjamin D; Kim, Eunkyoung; Martin, Alexandra N; Liu, Yi; Bentley, William E; Payne, Gregory F

2013-03-01

Exciting opportunities in bioelectronics will be facilitated by materials that can bridge the chemical logic of biology and the digital logic of electronics. Here we report the fabrication of a dual functional hydrogel film that can harvest electrons from its chemical environment and store these electrons by switching the film's redox-state. The hydrogel scaffold was formed by the anodic deposition of the aminopolysaccharide chitosan. Electron-harvesting function was conferred by co-depositing the enzyme glucose dehydrogenase (GDH) with chitosan. GDH catalyzes the transfer of electrons from glucose to the soluble redox-shuttle NADP(+). Electron-storage function was conferred by the redox-active food phenolic chlorogenic acid (CA) that was enzymatically grafted to the chitosan scaffold using tyrosinase. The grafted CA undergoes redox-cycling reactions with NADPH resulting in the net transfer of electrons to the film where they are stored in the reduced state of CA. The individual and dual functionalities of these films were demonstrated experimentally. There are three general conclusions from this proof-of-concept study. First, enzymatically-grafted catecholic moieties confer redox-capacitor function to the chitosan scaffold. Second, biological materials (i.e. chitosan and CA) and mechanisms (i.e. tyrosinase-mediated grafting) allow the reagentless fabrication of functional films that should be environmentally-friendly, safe and potentially even edible. Finally, the film's ability to mediate the transfer of electrons from a biological metabolite to an electrode suggests an approach to bridge the chemical logic of biology with the digital logic of electronics.

Does Previous Transradial Catheterization Preclude Use of the Radial Artery as a Conduit in Coronary Artery Bypass Surgery?

PubMed

Mounsey, Craig A; Mawhinney, Jamie A; Werner, Raphael S; Taggart, David P

2016-08-30

The radial artery (RA) is a commonly used conduit for coronary artery bypass grafting, and recent studies have demonstrated that it provides superior long-term patency rates to the saphenous vein in most situations. In addition, the RA is also being used with increasing frequency as the access point for coronary angiography and percutaneous coronary interventions. However, there has been concern for many years that these transradial procedures may have a detrimental impact on the function of RA grafts used in coronary artery bypass grafting, and there is now comprehensive evidence that such interventions cause morphologic and functional damage to the artery in situ. Despite this, there remain remarkably few studies investigating the use of previously cannulated RAs as grafts in coronary artery bypass surgery, and there are no clear guidelines on the use of the RA in coronary artery bypass grafting after its catheterization. This article will review concisely the evidence that transradial procedures cause damage to the RA, and discuss the impact this could have on previously cannulated RAs used as coronary artery bypass grafting conduits. On the basis of the evidence assessed, we make a number of recommendations to both surgeons and cardiologists regarding use of the RA in cardiovascular procedures. © 2016 American Heart Association, Inc.

Closure of the Radial Forearm Free Flap Donor Site Using the Combined Local Triangular Full-Thickness Skin Graft.

PubMed

Moreno-Sánchez, Manuel; González-García, Raúl; Ruiz-Laza, Luis; Manzano Solo de Zaldívar, Damián; Moreno-García, Carlos; Monje, Florencio

2016-01-01

Traditional donor-site closure has been associated with serious esthetic and functional morbidity. The purpose of this study was to assess morbidity in esthetics and function and measure the postoperative complications of the radial forearm free flap (RFFF) donor site after using combined local triangular full-thickness skin grafting. This prospective study of patients who underwent reconstruction of head and neck defects using an RFFF was conducted from July 2008 through December 2014. The donor site was repaired with a combined local triangular full-thickness skin graft. Quality of the scar, color match, tendon exposure, presence of necrosis, dehiscence of the suture, and presence of dysesthesia were recorded and analyzed using SPSS 21.0 software. One hundred consecutive patients (71 male and 29 female) underwent RFFF harvesting. RFFF donor-site defects ranged from 15 to 70 cm2; partial skin graft loss occurred in 7% of patients. Five patients (5%) had small dehiscences of the forearm skin graft, and 2 cases (2%) presented tendon exposure. In all cases, these sites healed secondarily by conservative management, with no final impairment of function. Esthetic results were considered excellent in 87%, good in 11%, and suboptimal in 2% of the cases. The combined local triangular full-thickness skin graft is a reliable method for closing RFFF donor-site defects because it obviates a second surgical site, it provides excellent color match and pliability, and it can be used for covering large defects of the donor site. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Revascularization procedures for Kienböck disease.

PubMed

Kakar, Sanjeev; Giuffre, Jennifer L; Shin, Alexander Y

2011-03-01

The goals of treatment in Kienböck disease include preservation of wrist function, maintaining normal wrist kinematics, and revascularization of the necrotic lunate when and if possible. A variety of pedicled vascularized bone graft options exist and include but are not limited to pedicled grafts from the volar radius, dorsal radius, metacarpal heads or bases, and pisiform. Of the various treatment options, pedicled vascularized bone grafts from the dorsal distal radius based on the fourth and fifth extensor compartment arteries has been successful in the revascularization of the necrotic lunate at our institution. Vascularized bone grafting is an attractive alternative to conventional bone grafting by improving the local biological environment and thereby promoting revascularization. Recent advances in the anatomy and physiology of vascularized pedicled bone grafts have increased our ability to apply them to the treatment of Kienböck disease. The purpose of this article is to describe the various types of pedicled vascularized bone graft available, to detail the vascular anatomy of the dorsal distal radius, and to describe the surgical technique of our preferred vascularized bone graft (the fourth+fifth extensor compartment artery graft). In addition, the indications, contraindications, and outcomes are described.

Revisiting double kidney transplantation: two kidneys provide better graft survival than one.

PubMed

Cruzado, J M; Fernandez, L; Riera, L; Bestard, O; Carrera, M; Torras, J; Gil Vernet, S; Melilli, E; Ngango, L; Grinyó, J M

2011-01-01

Double kidney transplantation is an accepted strategy to increase the donor pool. Regarding older donor kidneys, protocols for deciding to perform a dual or a single transplantation are mainly based on preimplantation biopsies. The aim of our study was to evaluate the long-term graft and patient survivals of our "Dual Kidney Transplant program." Patients who lost one of their grafts peritransplantation were used as controls. A total of 203 patients underwent kidney transplantation from December 1996 to January 2008 in our "old for old" renal transplantation program. We excluded 21 patients because of a nonfunctioning kidney, hyperacute rejection, or patient death with a functioning graft within the first month. Seventy-nine among 182 kidney transplantation the "old for old" program were dual kidney transplantation (DKT). Fifteen of 79 patients lost one of their kidney grafts (the uninephrectomized (UNX) UNX group). At 1 year, renal function was lower and proteinuria greater among the UNX than the DKT group. Patient survival was similar in both groups. However, death-censored graft survival was lower in UNX than DKT patients. The 5-year graft survival rate was 70% in UNX versus 93% in DKT cohorts (P = .04). In conclusion, taking into account the kidney shortage, our results may question whether the excellent transplant outcomes with DKT counter balance the reduced donor pool obviating acceptable transplant outcomes for more patients with single kidney transplantation. Copyright © 2011 Elsevier Inc. All rights reserved.

UV Grafting Modification of Polyethylene Separator for Liion Battery

NASA Astrophysics Data System (ADS)

Lv, Xiaoyuan; Li, Hua; Zhang, Zhiqiang; Chang, Hiunam; Jiang, Li; Liu, Hezhou

Polyethylene (PE) separator was modified by UV grafting methyl acrylate (MA) and nano-SiO2 composite layer. The structure of functional group and morphology of the separator were analyzed by Fourier transform infrared spectrum (FT-IR) and scanning electron microscope (SEM). The wetting behavior and the heat resistance of the separator were also investigated by contact angle test and thermal shrinkage test respectively. The results show that MA/nano-SiO2 composite layer is successfully grafted onto the PE separator, and the addition of the DI water and butanol can make the nano-SiO2 dispersed better and lead to a microporous structure of the grafting layer. The grafted separator has a better wettability and heat resistance than the pristine one.

Liver Ischemic Preconditioning (IPC) Improves Intestinal Microbiota Following Liver Transplantation in Rats through 16s rDNA-Based Analysis of Microbial Structure Shift

PubMed Central

Lu, Haifeng; Chen, Xinhua; Jiang, Jianwen; Liu, Hui; He, Yong; Ding, Songming; Hu, Zhenhua; Wang, Weilin; Zheng, Shusen

2013-01-01

Background Ischemia-reperfusion (I/R) injury is associated with intestinal microbial dysbiosis. The “gut-liver axis” closely links gut function and liver function in health and disease. Ischemic preconditioning (IPC) has been proven to reduce I/R injury in the surgery. This study aims to explore the effect of IPC on intestinal microbiota and to analyze characteristics of microbial structure shift following liver transplantation (LT). Methods The LT animal models of liver and gut IPC were established. Hepatic graft function was assessed by histology and serum ALT/AST. Intestinal barrier function was evaluated by mucosal ultrastructure, serum endotoxin, bacterial translocation, fecal sIgA content and serum TNF-α. Intestinal bacterial populations were determined by quantitative PCR. Microbial composition was characterized by DGGE and specific bacterial species were determined by sequence analysis. Principal Findings Liver IPC improved hepatic graft function expressed as ameliorated graft structure and reduced ALT/AST levels. After administration of liver IPC, intestinal mucosal ultrastructure improved, serum endotoxin and bacterial translocation mildly decreased, fecal sIgA content increased, and serum TNF-α decreased. Moreover, liver IPC promoted microbial restorations mainly through restoring Bifidobacterium spp., Clostridium clusters XI and Clostridium cluster XIVab on bacterial genus level. DGGE profiles indicated that liver IPC increased microbial diversity and species richness, and cluster analysis demonstrated that microbial structures were similar and clustered together between the NC group and Liver-IPC group. Furthermore, the phylogenetic tree of band sequences showed key bacteria corresponding to 10 key band classes of microbial structure shift induced by liver IPC, most of which were assigned to Bacteroidetes phylum. Conclusion Liver IPC cannot only improve hepatic graft function and intestinal barrier function, but also promote restorations of intestinal microbiota following LT, which may further benefit hepatic graft by positive feedback of the “gut-liver axis”. PMID:24098410

Liver ischemic preconditioning (IPC) improves intestinal microbiota following liver transplantation in rats through 16s rDNA-based analysis of microbial structure shift.

PubMed

Ren, Zhigang; Cui, Guangying; Lu, Haifeng; Chen, Xinhua; Jiang, Jianwen; Liu, Hui; He, Yong; Ding, Songming; Hu, Zhenhua; Wang, Weilin; Zheng, Shusen

2013-01-01

Ischemia-reperfusion (I/R) injury is associated with intestinal microbial dysbiosis. The "gut-liver axis" closely links gut function and liver function in health and disease. Ischemic preconditioning (IPC) has been proven to reduce I/R injury in the surgery. This study aims to explore the effect of IPC on intestinal microbiota and to analyze characteristics of microbial structure shift following liver transplantation (LT). The LT animal models of liver and gut IPC were established. Hepatic graft function was assessed by histology and serum ALT/AST. Intestinal barrier function was evaluated by mucosal ultrastructure, serum endotoxin, bacterial translocation, fecal sIgA content and serum TNF-α. Intestinal bacterial populations were determined by quantitative PCR. Microbial composition was characterized by DGGE and specific bacterial species were determined by sequence analysis. Liver IPC improved hepatic graft function expressed as ameliorated graft structure and reduced ALT/AST levels. After administration of liver IPC, intestinal mucosal ultrastructure improved, serum endotoxin and bacterial translocation mildly decreased, fecal sIgA content increased, and serum TNF-α decreased. Moreover, liver IPC promoted microbial restorations mainly through restoring Bifidobacterium spp., Clostridium clusters XI and Clostridium cluster XIVab on bacterial genus level. DGGE profiles indicated that liver IPC increased microbial diversity and species richness, and cluster analysis demonstrated that microbial structures were similar and clustered together between the NC group and Liver-IPC group. Furthermore, the phylogenetic tree of band sequences showed key bacteria corresponding to 10 key band classes of microbial structure shift induced by liver IPC, most of which were assigned to Bacteroidetes phylum. Liver IPC cannot only improve hepatic graft function and intestinal barrier function, but also promote restorations of intestinal microbiota following LT, which may further benefit hepatic graft by positive feedback of the "gut-liver axis".

Uptake and transcytosis of functionalized superparamagnetic iron oxide nanoparticles in an in vitro blood brain barrier model.

PubMed

Ivask, Angela; Pilkington, Emily H; Blin, Thomas; Käkinen, Aleksandr; Vija, Heiki; Visnapuu, Meeri; Quinn, John F; Whittaker, Michael R; Qiao, Ruirui; Davis, Thomas P; Ke, Pu Chun; Voelcker, Nicolas H

2018-01-30

Two major hurdles in nanomedicine are the limited strategies for synthesizing stealth nanoparticles and the poor efficacy of the nanoparticles in translocating across the blood brain barrier (BBB). Here we examined the uptake and transcytosis of iron oxide nanoparticles (IONPs) grafted with biomimetic phosphorylcholine (PC) brushes in an in vitro BBB model system, and compared them with bare, PEG or PC-PEG mixture grafted IONPs. Hyperspectral imaging indicated IONP co-localization with cells. Quantitative analysis with total reflection X-ray fluorescence spectrometry showed that after 24 h, 78% of PC grafted, 68-69% of PEG or PC-PEG grafted, and 30% of bare IONPs were taken up by the BBB. Transcytosis of IONPs was time-dependent and after 24 h, 16-17% of PC or PC-PEG mixture grafted IONPs had passed the BBB model, significantly more than PEG grafted or bare IONPs. These findings point out that grafting of IONPs with PC is a viable strategy for improving the uptake and transcytosis of nanoparticles.

Enhanced mesoscale climate projections in TAR and AR5 IPCC scenarios: a case study in a Mediterranean climate (Araucanía Region, south central Chile).

PubMed

Orrego, R; Abarca-Del-Río, R; Ávila, A; Morales, L

2016-01-01

Climate change scenarios are computed on a large scale, not accounting for local variations presented in historical data and related to human scale. Based on historical records, we validate a baseline (1962-1990) and correct the bias of A2 and B2 regional projections for the end of twenty-first century (2070-2100) issued from a high resolution dynamical downscaled (using PRECIS mesoscale model, hereinafter DGF-PRECIS) of Hadley GCM from the IPCC 3rd Assessment Report (TAR). This is performed for the Araucanía Region (Chile; 37°-40°S and 71°-74°W) using two different bias correction methodologies. Next, we study high-resolution precipitations to find monthly patterns such as seasonal variations, rainfall months, and the geographical effect on these two scenarios. Finally, we compare the TAR projections with those from the recent Assessment Report 5 (AR5) to find regional precipitation patterns and update the Chilean `projection. To show the effects of climate change projections, we compute the rainfall climatology for the Araucanía Region, including the impact of ENSO cycles (El Niño and La Niña events). The corrected climate projection from the high-resolution dynamical downscaled model of the TAR database (DGF-PRECIS) show annual precipitation decreases: B2 (-19.19 %, -287 ± 42 mm) and A2 (-43.38 %, -655 ± 27.4 mm per year. Furthermore, both projections increase the probability of lower rainfall months (lower than 100 mm per month) to 64.2 and 72.5 % for B2 and A2, respectively.

Enhanced mesoscale climate projections in TAR and AR5 IPCC scenarios: a case study in a Mediterranean climate (Araucanía Region, south central Chile)

DOE PAGES

Orrego, R.; Abarca-del-Rio, R.; Avila, A.; ...

2016-09-28

Here, climate change scenarios are computed on a large scale, not accounting for local variations presented in historical data and related to human scale. Based on historical records, we validate a baseline (1962–1990) and correct the bias of A2 and B2 regional projections for the end of twenty-first century (2070–2100) issued from a high resolution dynamical downscaled (using PRECIS mesoscale model, hereinafter DGF-PRECIS) of Hadley GCM from the IPCC 3rd Assessment Report (TAR). This is performed for the Araucanía Region (Chile; 37°–40°S and 71°–74°W) using two different bias correction methodologies. Next, we study high-resolution precipitations to find monthly patterns suchmore » as seasonal variations, rainfall months, and the geographical effect on these two scenarios. Finally, we compare the TAR projections with those from the recent Assessment Report 5 (AR5) to find regional precipitation patterns and update the Chilean `projection. To show the effects of climate change projections, we compute the rainfall climatology for the Araucanía Region, including the impact of ENSO cycles (El Niño and La Niña events). The corrected climate projection from the high-resolution dynamical downscaled model of the TAR database (DGF-PRECIS) show annual precipitation decreases: B2 (-19.19 %, -287 ± 42 mm) and A2 (-43.38 %, -655 ± 27.4 mm per year. Furthermore, both projections increase the probability of lower rainfall months (lower than 100 mm per month) to 64.2 and 72.5 % for B2 and A2, respectively.« less

Enhanced mesoscale climate projections in TAR and AR5 IPCC scenarios: a case study in a Mediterranean climate (Araucanía Region, south central Chile)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orrego, R.; Abarca-del-Rio, R.; Avila, A.

Here, climate change scenarios are computed on a large scale, not accounting for local variations presented in historical data and related to human scale. Based on historical records, we validate a baseline (1962–1990) and correct the bias of A2 and B2 regional projections for the end of twenty-first century (2070–2100) issued from a high resolution dynamical downscaled (using PRECIS mesoscale model, hereinafter DGF-PRECIS) of Hadley GCM from the IPCC 3rd Assessment Report (TAR). This is performed for the Araucanía Region (Chile; 37°–40°S and 71°–74°W) using two different bias correction methodologies. Next, we study high-resolution precipitations to find monthly patterns suchmore » as seasonal variations, rainfall months, and the geographical effect on these two scenarios. Finally, we compare the TAR projections with those from the recent Assessment Report 5 (AR5) to find regional precipitation patterns and update the Chilean `projection. To show the effects of climate change projections, we compute the rainfall climatology for the Araucanía Region, including the impact of ENSO cycles (El Niño and La Niña events). The corrected climate projection from the high-resolution dynamical downscaled model of the TAR database (DGF-PRECIS) show annual precipitation decreases: B2 (-19.19 %, -287 ± 42 mm) and A2 (-43.38 %, -655 ± 27.4 mm per year. Furthermore, both projections increase the probability of lower rainfall months (lower than 100 mm per month) to 64.2 and 72.5 % for B2 and A2, respectively.« less

Bridging Grafts and Transient Nerve Growth Factor Infusions Promote Long-Term Central Nervous System Neuronal Rescue and Partial Functional Recovery

NASA Astrophysics Data System (ADS)

Tuszynski, Mark H.; Gage, Fred H.

1995-05-01

Grafts of favorable axonal growth substrates were combined with transient nerve growth factor (NGF) infusions to promote morphological and functional recovery in the adult rat brain after lesions of the septohippocampal projection. Long-term septal cholinergic neuronal rescue and partial hippocampal reinnervation were achieved, resulting in partial functional recovery on a simple task assessing habituation but not on a more complex task assessing spatial reference memory. Control animals that received transient NGF infusions without axonal-growth-promoting grafts lacked behavioral recovery but also showed long-term septal neuronal rescue. These findings indicate that (i) partial recovery from central nervous system injury can be induced by both preventing host neuronal loss and promoting host axonal regrowth and (ii) long-term neuronal loss can be prevented with transient NGF infusions.

Functional engraftment of the medial ganglionic eminence cells in experimental stroke model.

PubMed

Daadi, Marcel M; Lee, Sang Hyung; Arac, Ahmet; Grueter, Brad A; Bhatnagar, Rishi; Maag, Anne-Lise; Schaar, Bruce; Malenka, Robert C; Palmer, Theo D; Steinberg, Gary K

2009-01-01

Currently there are no effective treatments targeting residual anatomical and behavioral deficits resulting from stroke. Evidence suggests that cell transplantation therapy may enhance functional recovery after stroke through multiple mechanisms. We used a syngeneic model of neural transplantation to explore graft-host communications that enhance cellular engraftment.The medial ganglionic eminence (MGE) cells were derived from 15-day-old transgenic rat embryos carrying green fluorescent protein (GFP), a marker, to easily track the transplanted cells. Adult rats were subjected to transient intraluminal occlusion of the medial cerebral artery. Two weeks after stroke, the grafts were deposited into four sites, along the rostro-caudal axis and medially to the stroke in the penumbra zone. Control groups included vehicle and fibroblast transplants. Animals were subjected to motor behavioral tests at 4 week posttransplant survival time. Morphological analysis demonstrated that the grafted MGE cells differentiated into multiple neuronal subtypes, established synaptic contact with host cells, increased the expression of synaptic markers, and enhanced axonal reorganization in the injured area. Initial patch-clamp recording demonstrated that the MGE cells received postsynaptic currents from host cells. Behavioral analysis showed reduced motor deficits in the rotarod and elevated body swing tests. These findings suggest that graft-host interactions influence the fate of grafted neural precursors and that functional recovery could be mediated by neurotrophic support, new synaptic circuit elaboration, and enhancement of the stroke-induced neuroplasticity.

Highlighting the Importance of Surface Grafting in Combination with a Layer-by-Layer Approach for Fabricating Advanced 3D Poly(l-lactide) Microsphere Scaffolds

PubMed Central

2016-01-01

A combined surface treatment (i.e., surface grafting and a layer-by-layer (LbL) approach) is presented to create advanced biomaterials, i.e., 3D poly(l-lactide) (PLLA) microsphere scaffolds, at room temperature. The grafted surface plays a crucial role in assembling polyelectrolyte multilayers (PEMs) onto the surface of the microspheres, thus improving the physicochemical properties of the 3D microsphere scaffolds. The grafted surface of the PLLA microspheres demonstrates much better PEM adsorption, improved surface coverage at low pH, and smoother surfaces at high pH compared with those of nongrafted surfaces of PLLA microspheres during the assembly of PEMs. They induce more swelling than nongrafted surfaces after the assembly of the PEMs and exhibit blue emission after functionalization of the microsphere surface with a fluorescent dye molecule. The 3D scaffolds functionalized with and without nanosheets not only exhibit good mechanical performance similar to the compressive modulus of cancellous bone but also exhibit the porosity required for cancellous bone regeneration. The magnetic nanoparticle-functionalized 3D scaffolds result in an electrical conductivity in the high range of semiconducting materials (i.e., 1–250 S cm–1). Thus, these 3D microsphere scaffolds fabricated by surface grafting and the LbL approach are promising candidates for bone tissue engineering. PMID:29503506

Micropatterned nanostructures: a bioengineered approach to mass-produce functional myocardial grafts.

PubMed

Serpooshan, Vahid; Mahmoudi, Morteza

2015-02-13

Cell-based therapies are a recently established path for treating a wide range of human disease. Tissue engineering of contractile heart muscle for replacement therapy is among the most exciting and important of these efforts. However, current in vitro techniques of cultivating functional mature cardiac grafts have only been moderately successful due to the poor capability of traditional two-dimensional cell culture systems to recapitulate necessary in vivo conditions. In this issue, Kiefer et al introduce a laser-patterned nanostructured substrate (Al/Al2O3 nanowires) for efficient maintenance of oriented human cardiomyocytes, with great potential to open new roads to mass-production of contractile myocardial grafts for cardiovascular tissue engineering.

Heart transplantation on the first day of life from an anencephalic donor.

PubMed

Parisi, F; Squitieri, C; Carotti, A; Di Carlo, D; Gagliardi, M G

1999-05-01

Heart transplantation on the first day of life, and graft harvesting from anencephalic donors, have been very rare events in the history of transplantation. At Bambino Gesù Hospital (Rome), heart transplantation was performed on a newborn 9 h after birth, using a graft harvested from an anencephalic donor. This graft achieved a good cardiocirculatory function, but the recipient died of necrotizing enterocolitis (NEC) on post-operative day (POD) 10. Despite failure, this case and other reports support the concept that hearts from anencephalic donors can work normally, and indicate that heart transplantation on the first day of life may have a favorable outcome if postoperative maintenance of multi-organ balance and function is successful.

Micropatterned nanostructures: a bioengineered approach to mass-produce functional myocardial grafts

NASA Astrophysics Data System (ADS)

Serpooshan, Vahid; Mahmoudi, Morteza

2015-02-01

Cell-based therapies are a recently established path for treating a wide range of human disease. Tissue engineering of contractile heart muscle for replacement therapy is among the most exciting and important of these efforts. However, current in vitro techniques of cultivating functional mature cardiac grafts have only been moderately successful due to the poor capability of traditional two-dimensional cell culture systems to recapitulate necessary in vivo conditions. In this issue, Kiefer et al [1] introduce a laser-patterned nanostructured substrate (Al/Al2O3 nanowires) for efficient maintenance of oriented human cardiomyocytes, with great potential to open new roads to mass-production of contractile myocardial grafts for cardiovascular tissue engineering.

Laundering durable antibacterial cotton fabrics grafted with pomegranate-shaped polymer wrapped in silver nanoparticle aggregations

NASA Astrophysics Data System (ADS)

Liu, Hanzhou; Lv, Ming; Deng, Bo; Li, Jingye; Yu, Ming; Huang, Qing; Fan, Chunhai

2014-08-01

To improve the laundering durability of the silver functionalized antibacterial cotton fabrics, a radiation-induced coincident reduction and graft polymerization is reported herein where a pomegranate-shaped silver nanoparticle aggregations up to 500 nm can be formed due to the coordination forces between amino group and silver and the wrapping procedure originated from the coincident growth of the silver nanoparticles and polymer graft chains. This pomegranate-shaped silver NPAs functionalized cotton fabric exhibits outstanding antibacterial activities and also excellent laundering durability, where it can inactivate higher than 90% of both E. coli and S. aureus even after 50 accelerated laundering cycles, which is equivalent to 250 commercial or domestic laundering cycles.

Point-of-care instrument for monitoring tissue health during skin graft repair

NASA Astrophysics Data System (ADS)

Gurjar, R. S.; Seetamraju, M.; Zhang, J.; Feinberg, S. E.; Wolf, D. E.

2011-06-01

We have developed the necessary theoretical framework and the basic instrumental design parameters to enable mapping of subsurface blood dynamics and tissue oxygenation for patients undergoing skin graft procedures. This analysis forms the basis for developing a simple patch geometry, which can be used to map by diffuse optical techniques blood flow velocity and tissue oxygenation as a function of depth in subsurface tissue.skin graft, diffuse correlation analysis, oxygen saturation.

Autologous transplantation of bone marrow-derived mesenchymal stem cells: a promising therapeutic strategy for prevention of skin-graft contraction.

PubMed

Xu, Y; Huang, S; Fu, X

2012-07-01

Hypertrophic scars result from abnormal healing of severe burns, and are characterized by loss of the original structure and function of the skin. Transplantation of autologous split skin is the preferred treatment after scar excision; however, there will be some unavoidable degree of contraction within the grafts. To our knowledge, it is very rare that bone marrow-derived mesenchymal stem cells (BM-MSCs) have been used for the treatment of skin-graft contraction. However, in our clinics, we found that during a 2-year follow-up analysis, areas treated with autologous BM-MSCs combined with transplantation of split skin were less likely to have contraction of the skin grafts than areas treated with skin grafts alone. This result indicates that BM-MSCs may be a potential and promising treatment to prevent contraction of skin grafts. © The Author(s). CED © 2012 British Association of Dermatologists.

Intraoperative coronary grafts flow measurement using the TTFM flowmeter: results from a domestic sample.

PubMed

Succi, José Ernesto; Gerola, Luis Roberto; Succi, Guilherme de Menezes; Kim, Hyong Chun; Paredes, Jorge Edwin Morocho; Bufollo, Enio

2012-01-01

To evaluate intraoperative graft patency and identify grafts under risk of early occlusion. Fifty four patients were submitted to coronary artery bypass surgery and the graft flow was assessed by the Flowmeter (Medtronic Medistim), which utilizes the TTFM method. Three patients had left main disease and 48 had normal or mildly reduced left ventricular function. In hospital mortality was 3.7% (two patients), one for mesenteric thrombosis and one due to cardiogenic chock. Seventeen patients (34%) were submitted to off pump CABG. Arterial Graft flow measures ranged from 8 to 106 ml/min (average 31.14 ml/min), and venous grafts flow ranged from 9 to 149 ml/min (average 50.42 ml/min). Flowmeter use represents higher safety both for patients and surgeons. Even under legal aspects, the documentation provided by the device can avoid future questionings.

A free vascularized tibia-fibular composite graft for the traumatic femoral bony defect of a 6-year-old boy with 10-year follow up: a case report

PubMed Central

2013-01-01

Introduction Free vascularized fibular grafts have been widely used for the reconstruction of long bone defects. However, the use of a vascularized tibial graft is precluded by its weight-bearing function and unacceptable donor site morbidity. Case presentation We present a rare case of using a vascularized tibia-fibular composite graft taken from a 6-year-old Chinese boy’s ipsilateral lower leg to reconstruct a large bony defect of his traumatic femur. Hypertrophy of the tibial graft, good remodeling of the femoral shaft, and atrophy of the unloaded fibular graft were noted at the 10-year follow up. He was able to participate in outdoor activities such as basketball while wearing his prosthesis. Conclusions The 10-year follow up demonstrates the feasibility of this salvage procedure for a floating knee injury with neurovascular compromise. PMID:23714102

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).

Surface grafting of cellulose nanocrystals with poly(ethylene oxide) in aqueous media.

PubMed

Kloser, Elisabeth; Gray, Derek G

2010-08-17

Aqueous suspensions of poly(ethylene oxide)-grafted nanocrystalline cellulose (PEO-grafted NCC) were prepared in order to achieve steric instead of electrostatic stabilization. A two-step process was employed: in the first step NCC suspensions prepared by sulfuric acid hydrolysis were desulfated with sodium hydroxide, and in the second step the surfaces of the crystals were functionalized with epoxy-terminated poly(ethylene oxide) (PEO epoxide) under alkaline conditions. The PEO-grafted samples were analyzed by conductometric titration, ATR-IR, solid-state NMR, MALDI-TOF MS, SEC MALLS, and AFM. The covalent nature of the linkage was confirmed by weight increase and MALDI-TOF analysis. The PEO-grafted cellulose nanocrystals (CNCs) formed a stable colloidal suspension that remained well dispersed, while the desulfated nanoparticles aggregated and precipitated. Upon concentration of the PEO-grafted aqueous NCC suspension, a chiral nematic phase was observed.

Graft union formation in grapevine induces transcriptional changes related to cell wall modification, wounding, hormone signalling, and secondary metabolism

PubMed Central

Cookson, Sarah Jane; Clemente Moreno, Maria José; Hevin, Cyril; Nyamba Mendome, Larissa Zita; Delrot, Serge; Trossat-Magnin, Claudine; Ollat, Nathalie

2013-01-01

Grafting is particularly important to the cultivation of perennial crops such as grapevine (Vitis vinifera) because rootstocks can provide resistance to soil-borne pests and diseases as well as improve tolerance to some abiotic stresses. Successful grafting is a complex biochemical and structural process beginning with the adhesion of the two grafted partners, followed by callus formation and the establishment of a functional vascular system. At the molecular level, the sequence of events underlying graft union formation remains largely uncharacterized. The present study investigates the transcriptome of grapevine rootstock and graft interface tissues sampled 3 d and 28 d after grafting of over-wintering stems in the spring. Many genes were differentially expressed over time, from 3 d to 28 d after grafting, which could be related to the activation of stem growth and metabolic activity in the spring. This hypothesis is supported by the up-regulation of many genes associated with cell wall synthesis, and phloem and xylem development. Generally, there was an up-regulation of gene expression in the graft interface tissue compared with the rootstock, particularly genes involved in cell wall synthesis, secondary metabolism, and signalling. Although there was overlap between the genes differentially expressed over time (from 3 d to 28 d after grafting) with the gene differentially expressed between the rootstock and the graft interface, numerous graft interface-specific genes were identified. PMID:23698628

Peritransplant Soluble CD30 as a Risk Factor for Slow Kidney Allograft Function, Early Acute Rejection, Worse Long-Term Allograft Function, and Patients' Survival

PubMed Central

Ostapenko, Tetyana I.; Nykonenko, Tamara N.; Nesterenko, Svitlana N.; Nykonenko, Olexandr S.

2017-01-01

Background We aimed to determine whether serum soluble CD30 (sCD30) could identify recipients at high risk for unfavorable early and late kidney transplant outcomes. Methods Serum sCD30 was measured on the day of kidney transplantation and on the 4th day posttransplant. We assessed the value of these measurements in predicting delayed graft function, slow graft function (SGF), acute rejection (AR), pyelonephritis, decline of allograft function after 6 months, and graft and patient survival during 5 years of follow-up in 45 recipients. Results We found the association between low pretransplant serum levels of sCD30 and SGF. The absence of significant decrease of sCD30 on the 4th day posttransplant was characteristic for SGF, early AR (the 8th day–6 months), late AR (>6 months), and early pyelonephritis (the 8th day–2 months). Lower pretransplant and posttransplant sCD30 predicted worse allograft function at 6 months and 2 years, respectively. Higher pretransplant sCD30 was associated with higher frequency of early AR, and worse patients' survival, but only in the recipients of deceased-donor graft. Pretransplant sCD30 also allowed to differentiate patients with early pyelonephritis and early AR. Conclusions Peritransplant sCD30 is useful in identifying patients at risk for unfavorable early and late transplant outcomes. PMID:28694560

Surface-functionalized mesoporous carbon materials

DOEpatents

Dai, Sheng; Gorka, Joanna; Mayes, Richard T.

2016-02-02

A functionalized mesoporous carbon composition comprising a mesoporous carbon scaffold having mesopores in which polyvinyl polymer grafts are covalently attached, wherein said mesopores have a size of at least 2 nm and up to 50 nm. Also described is a method for producing the functionalized mesoporous composition, wherein a reaction medium comprising a precursor mesoporous carbon, vinyl monomer, initiator, and solvent is subjected to sonication of sufficient power to result in grafting and polymerization of the vinyl monomer into mesopores of the precursor mesoporous carbon. Also described are methods for using the functionalized mesoporous carbon, particularly in extracting metal ions from metal-containing solutions.

Early Growth Response-1 Plays an Important Role in Ischemia-Reperfusion Injury in Lung Transplants by Regulating Polymorphonuclear Neutrophil Infiltration.

PubMed

Yamamoto, Sumiharu; Yamane, Masaomi; Yoshida, Osamu; Waki, Naohisa; Okazaki, Mikio; Matsukawa, Akihiro; Oto, Takahiro; Miyoshi, Shinichiro

2015-11-01

Early growth response-1 (Egr-1) has been shown to be a trigger-switch transcription factor that is involved in lung ischemia-reperfusion injury (IRI). Mouse lung transplants were performed in wild-type (WT) C57BL/6 and Egr1-knockout (KO) mice in the following donor → recipient combinations: WT → WT, KO → WT, WT → KO, and KO → KO to determine whether the presence of Egr-1 in the donor or recipient is the most critical factor for IRI. Pulmonary grafts were retrieved after 18 hours of ischemia after 4 hours of reperfusion. We analyzed graft function by analyzing arterial blood gas and histology in each combination and assessed the effects of Egr1 depletion on inflammatory cytokines that are regulated by Egr-1 as well on polymorphonuclear neutrophil (PMN) infiltration. Deletion of Egr1 improved pulmonary graft function in the following order of donor → recipient combinations: WT → WT < WT → KO < KO → WT < KO → KO. Polymerase chain reaction assays for Il1B, Il6, Mcp1, Mip2, Icam1, and Cox2 showed significantly lower expression levels in the KO → KO group than in the other groups. Immunohistochemistry demonstrated clear Egr-1 expression in the nuclei of pulmonary artery endothelial cells and PMN cytoplasm in the WT grafts. Flow cytometry analysis showed that Egr1 deletion reduced PMN infiltration and that the extent of reduction correlated with graft function. Both graft and recipient Egr-1 played a role in lung IRI, but the graft side contributed more to this phenomenon through regulation of PMN infiltration. Donor Egr-1 expression in pulmonary artery endothelial cells may play an important role in PMN infiltration, which results in IRI after lung transplantation.

Scleral patch grafts in the management of uveal and ocular surface tumors.

PubMed

Barman, Manabjyoti; Finger, Paul T; Milman, Tatyana

2012-12-01

To evaluate the outcome of scleral patch grafts in a series of patients undergoing management for uveal and ocular surface tumors. Case series. Ten patients underwent scleral patch grafting. Five patients had uveal melanoma with extrascleral extension, 2 patients had scleromalacia secondary to plaque radiotherapy for uveal melanoma, 2 patients had suspicious uveoscleral nevi, and 1 patient had invasive conjunctival squamous cell carcinoma with scleral necrosis. Retrospective, interventional, noncomparative chart review of patients undergoing treatment for ocular tumors followed by scleral grafts in a tertiary eye care center in the United States between September 2003 and January 2011. Sclera was reconstructed with allogenic scleral grafts. Clinical observations were performed after grafting. Structural integrity, appearance, and stability of the grafts. Ten patients were reviewed. All melanoma cases received plaque radiotherapy with palladium 103. The cases with nevi and squamous cell carcinoma underwent local resection with cryotherapy as primary treatment. In 8 cases, scleral grafting was performed as part of the initial surgery. In all of these cases, satisfactory anatomic and functional outcomes were achieved. In 2 cases with scleromalacia secondary to radiotherapy for uveal melanoma, grafts were placed several years after the initial treatment. In these 2 cases, one showed signs of graft retraction, whereas another showed graft thinning. No patients experienced graft infection, rejection, or tumor recurrence. In this series, scleral grafts were well accepted when placed as part of the primary tumor management despite synchronous radiotherapy, scleral resection, or cryotherapy. Grafting was less successful when performed as a late procedure for radiation-induced scleromalacia. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Photo-Curable Metal-Chelating Coatings Offer a Scalable Approach to Production of Antioxidant Active Packaging.

PubMed

Lin, Zhuangsheng; Goddard, Julie

2018-02-01

Synthetic metal chelators (for example, ethylenediaminetetraacetic acid, EDTA) are widely used as additives to control trace transition metal induced oxidation in consumer products. To enable removal of synthetic chelators in response to increasing consumer demand for clean label products, metal-chelating active food packaging technologies have been developed with demonstrated antioxidant efficacy in simulated food systems. However, prior work in fabrication of metal-chelating materials leveraged batch chemical reactions to tether metal-chelating ligands, a process with limited industrial translatability for large-scale fabrication. To improve the industrial translatability, we have designed a 2-step laminated photo-grafting process to introduce metal chelating functionality onto common polymeric packaging materials. Iminodiacetic acid (IDA) functionalized materials were fabricated by photo-grafting poly(acrylic acid) onto polypropylene (PP) films, followed by a second photo-grafting process to graft-polymerize an IDA functionalized vinyl monomer (GMA-IDA). The photo-grafting was conducted under atmospheric conditions and was completed in 2 min. The resulting IDA functionalized metal-chelating material was able to chelate iron and copper, and showed antioxidant efficacy against ascorbic acid degradation, supporting its potential to be used synergistically with natural antioxidants for preservation of food and beverage products. The 2-step photo-grafting process improves the throughput of active packaging coatings, enabling potential roll-to-roll fabrication of metal-chelating active packaging materials for antioxidant food packaging applications. To address consumer and retail demands for "clean label" foods and beverages without a corresponding loss in product quality and shelf life, producers are seeking next generation technologies such as active packaging. In this work, we will report the synthesis of metal-chelating active packaging films, which enable removal of the synthetic additive, ethylenediamine tetraacetic acid. The new synthesis technique improves the throughput of metal-chelating active packaging coatings, enabling potential roll-to-roll fabrication of the materials for antioxidant food packaging applications. © 2018 Institute of Food Technologists®.

Quality of life and female sexual function after skinning vulvectomy with split-thickness skin graft in women with vulvar intraepithelial neoplasia or vulvar Paget disease.

PubMed

Lavoué, V; Lemarrec, A; Bertheuil, N; Henno, S; Mesbah, H; Watier, E; Levêque, J; Morcel, K

2013-12-01

Vulvar intraepithelial neoplasia (VIN) and vulvar Paget disease are managed with either vulvectomy, destructive treatments (laser, antimitotic drugs) or immunostimulants. All these options are associated with functional complications. The purpose of this study was to evaluate the surgical technique consisting of skinning vulvectomy with split-thickness skin graft, and its effect on overall quality of life and sexual function. A retrospective study was conducted on thirteen patients who underwent skinning vulvectomy with split-thickness skin graft between 1999 and 2009. Overall quality of life and sexual function were assessed with the Medical Outcome Study Short Form 36 (MOS SF-36) and Female Sexual Function Index (FSFI), respectively. The median age of patients was 54 (range: 33-77) years. Three patients had Paget disease and 10 patients had VIN lesions. The excision margins were clear in 46% of cases. The incidence of occult cancer was 31%. The mean follow-up period was 77 (±35) months. Four patients experienced a relapse of their intraepithelial disease. The mean disease-free survival was 58 (±44) months. There was no significant difference in MOS SF-36 scores between the study population and the general population. The patients assessed with the FSFI regained normal sexual function after the surgical procedure. Skinning vulvectomy with split-thickness skin graft is a feasible technique yielding good results in terms of quality of life and sexual function. It enables occult cancer to be diagnosed in patients with VIN or Paget disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Gender Matches in Liver Transplant Allocation: Matched and Mismatched Male-Female Donor-Recipient Combinations; Long-term Follow-up of More Than 2000 Patients at a Single Center.

PubMed

Schoening, Wenzel N; Helbig, Michael; Buescher, Niklas; Andreou, Andreas; Bahra, Marcus; Schmitz, Volker; Pascher, Andreas; Pratschke, Johann; Seehofer, Daniel

2016-04-01

The influence of donor-recipient sex mismatches on long-term graft survival after liver transplant is controversial. In this study, our aim was to characterize the differences in long-term graft outcome after liver transplant in more than 2000 cases with special regard to sex match and mismatch. In this retrospective, single center study of 2144 adult primary liver transplant recipients (median follow-up of 92 months), we analyzed specific long-term graft survival and the effect of different donor and recipient sex combinations (Kaplan-Meier, multivariate regression). In the 15-year follow-up, female recipients (58.6%) had significantly better graft survival than male recipients did (51.6%, P = .031). Matched and mismatched male-female combinations revealed significant differences (P = .003): a male donor-female recipient combination showed the best 15-year graft survival (61.1%), and a female donor-male recipient combination showed the worst graft survival (48.6%), whereas male-male (53.3%) and female-female combinations (55.6%) were not significantly different (P = .967). Donor age (P ≤ .0001), body mass index (P = .021), female sex (P = .015), Eurotransplant Donor Risk Index > 1.4 (P ≤ .001), recipients' age (P < .0001), indication for liver transplant (P < .0001), and kidney function (P = .003) significantly affected graft survival. In the multivariate analysis model, a Eurotransplant Donor Risk Index > 1.4 and impaired kidney function at liver transplant again emerged as significant negative predictors. Female donors and male recipients showed significantly more unfavorable characteristics concerning long-term graft survival. The impressive long-term graft survival benefit of male donor-female recipient versus female donor-male recipient and of male donor-female recipient versus matched groups (male-male, female-female) in liver transplant may be caused by significant differences in donor quality and recipient characteristics and may not be related to sex itself.

The versatile subepithelial connective tissue graft: a literature update.

PubMed

Karthikeyan, B V; Khanna, Divya; Chowdhary, Kamedh Yashawant; Prabhuji, M Lv

2016-01-01

Harmony between hard and soft tissue morphologies is essential for form, function, and a good esthetic outlook. Replacement grafts for correction of soft tissue defects around the teeth have become important to periodontal plastic and implant surgical procedures. Among a multitude of surgical techniques and graft materials reported in literature, the subepithelial connective tissue graft (SCTG) has gained wide popularity and acceptance. The purpose of this article is to acquaint clinicians with the current understanding of the versatile SCTG. Key factors associated with graft harvesting as well as applications, limitations, and complications of SCTGs are discussed. This connective tissue has shown excellent short- and long-term stability, is easily available, and is economical to use. The SCTG should be considered as an alternative in all periodontal reconstruction surgeries.

[Cutaneo-fascial flaps in restorative and reconstructive surgery of burns].

PubMed

Kurbanov, Sh I; Moroz, V Iu; Grishkevich, V M

1990-06-01

On the basis of experience with the treatment of more than 1,500 patients with post-burn defects, deformities, and trophic ulcers, the authors distinguished types of affection in which the traditional methods are ineffective. These 133 patients were subjected to plasty with ++cutaneo-fascial grafts; the zones of donor areas from which the grafts are taken are determined. Plasty with ++cutaneo-fascial grafts is indicated in defects of the face, deformity of the neck, total adduction contracture of the arm, defect of the breast, and affections of the hand, leg, and foot. Concrete grafts and the site from which they are taken for restoration of certain regions of the body are suggested. ++Cutaneo-fascial grafts make it possible to restore the shape, function, and the skin of the involved region.

Treatment of long ureteric strictures with buccal mucosal grafts.

PubMed

Kroepfl, Darko; Loewen, Heinrich; Klevecka, Virgilijus; Musch, Michael

2010-05-01

To describe the reconstruction of long ureteric strictures using buccal mucosal patch grafts and to report the intermediate-term functional outcome. Between November 2000 and October 2006 reconstruction of seven long ureteric strictures using buccal mucosal patch grafts and omental wrapping was performed in five women (one with bilateral strictures) and one man. The surgical steps of stricture reconstruction and wrapping with omentum are described in detail. Stricture recurrence was defined as persistent impaired ureteric drainage as displayed by imaging techniques or the necessity to prolong JJ stenting. Patency rates and stricture recurrence-free survival rates are provided. With a median follow up of 18 months five of the seven strictures were recurrence-free. Graft take was good in all patients. In one asymptomatic patient, there was impaired ureteric drainage on the reconstructed side, and in one patient with reconstruction of both ureters prolonged JJ stenting of one side was necessary. In both patients, the impaired drainage was caused by persistent stricture below the reconstructed ureteric segments. At intermediate-term follow-up in a small group of patients with long ureteric strictures, treatment with buccal mucosal patch grafts and omental wrapping showed good functional outcome.

Grafted functional groups on expanded tetrafluoroethylene (ePTFE) support for fuel cell and water transport membranes

DOEpatents

Fuller, Timothy J.; Jiang, Ruichun

2017-01-24

A method for forming a modified solid polymer includes a step of contacting a solid fluorinated polymer with a sodium sodium-naphthalenide solution to form a treated fluorinated solid polymer. The treated fluorinated solid polymer is contacted with carbon dioxide, sulfur dioxide, or sulfur trioxide to form a solid grafted fluorinated polymer. Characteristically, the grafted fluorinated polymer includes appended CO.sub.2H or SO.sub.2H or SO.sub.3H groups. The solid grafted fluorinated polymer is advantageously incorporated into a fuel cell as part of the ion-conducting membrane or a water transport membrane in a humidifier.

A randomized trial comparing ReCell system of epidermal cells delivery versus classic skin grafts for the treatment of deep partial thickness burns.

PubMed

Gravante, G; Di Fede, M C; Araco, A; Grimaldi, M; De Angelis, B; Arpino, A; Cervelli, V; Montone, A

2007-12-01

Our purpose was to directly compare results obtained with the ReCell system and the classic skin grafting for epidermal replacement in deep partial thickness burns. We recruited all patients with deep partial thickness burns admitted at the Burn Centre of S. Eugenio Hospital in Rome over 2 years. Enrollment was conducted with a controlled strategy--sampling chart--that allowed homogeneous groups (ReCell and skin grafting) for age, gender, type of burns and total burn surface area (TBSA). We evaluated as primary endpoints of the study the (i) time for complete epithelization (both treated area and biopsy site) and (ii) aesthetic and functional quality of the epithelization (color, joint contractures). Secondary endpoints were the assessment of infections, inflammations or any adverse effects of the ReCell procedure, particular medications assumed, postoperative pain. Eighty-two patients were analyzed in two homogeneous groups. All of them received adequate epidermal replacement, but skin grafting was faster than ReCell (p<0.05). On the contrary, ReCell biopsy areas and postoperative pain were smaller than classic grafting (p<0.05). The aesthetic and functional outcomes were similar between procedures. ReCell is a feasible, simple and safe technique. It gives similar results to skin grafting but, harvesting minor areas, can open possible future applications in the management of large-burns patients.

Scaffold microstructure effects on functional and mechanical performance: Integration of theoretical and experimental approaches for bone tissue engineering applications.

PubMed

Cavo, Marta; Scaglione, Silvia

2016-11-01

The really nontrivial goal of tissue engineering is combining all scaffold micro-architectural features, affecting both fluid-dynamical and mechanical performance, to obtain a fully functional implant. In this work we identified an optimal geometrical pattern for bone tissue engineering applications, best balancing several graft needs which correspond to competing design goals. In particular, we investigated the occurred changes in graft behavior by varying pore size (300μm, 600μm, 900μm), interpore distance (equal to pore size or 300μm fixed) and pores interconnection (absent, 45°-oriented, 90°-oriented). Mathematical considerations and Computational Fluid Dynamics (CFD) tools, here combined in a complete theoretical model, were carried out to this aim. Poly-lactic acid (PLA) based samples were realized by 3D printing, basing on the modeled architectures. A collagen (COL) coating was also realized on grafts surface and the interaction between PLA and COL, besides the protein contribution to graft bioactivity, was evaluated. Scaffolds were extensively characterized; human articular cells were used to test their biocompatibility and to evaluate the theoretical model predictions. Grafts fulfilled both the chemical and physical requirements. Finally, a good agreement was found between the theoretical model predictions and the experimental data, making these prototypes good candidates for bone graft replacements. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparing the Efficacy of Triple Nerve Transfers with Nerve Graft Reconstruction in Upper Trunk Obstetric Brachial Plexus Injury.

PubMed

O'Grady, Kathleen M; Power, Hollie A; Olson, Jaret L; Morhart, Michael J; Harrop, A Robertson; Watt, M Joe; Chan, K Ming

2017-10-01

Upper trunk obstetric brachial plexus injury can cause profound shoulder and elbow dysfunction. Although neuroma excision with interpositional sural nerve grafting is the current gold standard, distal nerve transfers have a number of potential advantages. The goal of this study was to compare the clinical outcomes and health care costs between nerve grafting and distal nerve transfers in children with upper trunk obstetric brachial plexus injury. In this prospective cohort study, children who underwent triple nerve transfers were followed with the Active Movement Scale for 2 years. Their outcomes were compared to those of children who underwent nerve graft reconstruction. To assess health care use, a cost analysis was also performed. Twelve patients who underwent nerve grafting were compared to 14 patients who underwent triple nerve transfers. Both groups had similar baseline characteristics and showed improved shoulder and elbow function following surgery. However, the nerve transfer group displayed significantly greater improvement in shoulder external rotation and forearm supination 2 years after surgery (p < 0.05). The operative time and length of hospital stay were significantly lower (p < 0.05), and the overall cost was approximately 50 percent less in the nerve transfer group. Triple nerve transfer for upper trunk obstetric brachial plexus injury is a feasible option, with better functional shoulder external rotation and forearm supination, faster recovery, and lower cost compared with traditional nerve graft reconstruction. Therapeutic, II.

Mesenchymal stem cells increase skin graft survival time and up-regulate PD-L1 expression in splenocytes of mice.

PubMed

Moravej, Ali; Geramizadeh, Bita; Azarpira, Negar; Zarnani, Amir-Hassan; Yaghobi, Ramin; Kalani, Mehdi; Khosravi, Maryam; Kouhpayeh, Amin; Karimi, Mohammad-Hossein

2017-02-01

Recently, mesenchymal stem cells (MSCs) have gained considerable interests as hopeful therapeutic cells in transplantation due to their immunoregulatory functions. But exact mechanisms underlying MSCs immunoregulatory function is not fully understood. Herein, in addition to investigate the ability of MSCs to prolong graft survival time, the effects of them on the expression of PD-L1 and IDO immunomodulatory molecules in splenocytes of skin graft recipient mice was clarified. To achieve this goal, full-thickness skins were transplanted from C57BL/6 to BALB/c mice. MSCs were isolated from bone marrow of BALB/c mice and injected to the recipient mice. Skin graft survival was monitored daily to determine graft rejection time. On days 2, 5 and 10 post skin transplantation, serum cytokine levels and expression of PD-L1 and IDO mRNA and protein in the splenocytes of recipient mice were evaluated. The results showed that administration of MSCs prolonged skin graft survival time from 11 to 14 days. On days 2 and 5 post transplantation, splenocytes PD-L1 expression and IL-10 serum level in MSCs treated mice were higher than those in the controls, while IL-2 and IFN-γ levels were lower. Rejection in MSCs treated mice was accompanied by an increase in IL-2 and IFN-γ, and decrease in PD-L1 expression and IL-10 level. No difference in the expression of IDO between MSCs treated mice and controls was observed. In conclusion, we found that one of the mechanisms underlying MSCs immunomodulatory function could be up-regulating PD-L1 expression. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Outcome of deceased donor renal transplantation in diabetic nephropathy: a single-center experience from a developing country.

PubMed

Kute, Vivek B; Godara, Suraj M; Shah, Pankaj R; Jain, Siddharth H; Engineer, D P; Patel, Himanshu V; Gumber, Manoj R; Munjappa, Bipin C; Sainaresh, V V; Vanikar, Aruna V; Modi, Pranjal R; Shah, Veena R; Trivedi, Hargovind L

2012-02-01

Type 2 diabetes mellitus (DM) is the commonest cause of end-stage renal disease (ESRD) worldwide. Renal transplantation (RTx) is the best therapeutic modality for such patients. First-degree relatives of patients with type 2 DM have high risk of diabetes/pre-diabetes. Parents are often too old to be suitable donors, and siblings/children/spouse are either not suitable/acceptable or do not come forward for organ donation. This leaves deceased donation (DD) as only suitable donors. Data scarcity on DDRTx outcome in diabetic nephropathy (DN) prompted us to review our experience. This retrospective single-center 10-year study was undertaken to evaluate patient/graft survival, graft function, rejection episodes, and mortality in these patients. Between January 2001 and March 2011, thirty-five DN-ESRD patients underwent DDRTx in our center following cardiac fitness assessment of recipients. All patients received single-dose rabbit-anti-thymocyte globulin for induction and steroids, calcineurin inhibitor, and mycophenolate mofetil/azathioprine for maintenance immunosuppression. Mean recipient age was 49.66 ± 6.76 years, and 25 were men. Mean donor age was 50 ± 16.45 years, 23 were men. Over a mean follow-up of 2.28 ± 2.59 years, patient and graft survival rates were 68.5% and 88.5%, respectively, with mean SCr of 1.9 ± 0.62 mg/dl. Delayed graft function was observed in 34.3% patients, and 25.7% had biopsy-proven acute rejection; 31.5% patients died, mainly because of infections (22.8%), coronary artery disease (2.86%), and cerebrovascular events (5.7%). DDRTx in patients with DN has acceptable graft function and patient/graft survival over 10-year follow-up in our center and, therefore, we believe it should be encouraged.

Sustained release of neurotrophin-3 via calcium phosphate-coated sutures promotes axonal regeneration after spinal cord injury.

PubMed

Hanna, Amgad; Thompson, Daniel L; Hellenbrand, Daniel J; Lee, Jae-Sung; Madura, Casey J; Wesley, Meredith G; Dillon, Natalie J; Sharma, Tapan; Enright, Connor J; Murphy, William L

2016-07-01

Because of the dynamics of spinal cord injury (SCI), the optimal treatment will almost certainly be a combination approach to control the environment and promote axonal growth. This study uses peripheral nerve grafts (PNGs) as scaffolds for axonal growth while delivering neurotrophin-3 (NT-3) via calcium phosphate (CaP) coatings on surgical sutures. CaP coating was grown on sutures, and NT-3 binding and release were characterized in vitro. Then, the NT-3-loaded sutures were tested in a complete SCI model. Rats were analyzed for functional improvement and axonal growth into the grafts. The CaP-coated sutures exhibited a burst release of NT-3, followed by a sustained release for at least 20 days. Functionally, the rats with PNGs + NT-3-loaded sutures and the rats treated with PNGs scored significantly higher than controls on day 56 postoperatively. However, functional scores in rats treated with PNGs + NT-3-loaded suture were not significantly different from those of rats treated with PNGs alone. Cholera toxin subunit B (CTB) labeling rostral to the graft was not observed in any controls, but CTB labeling rostral to the graft was observed in almost all rats that had had a PNG. Neurofilament labeling on transverse sections of the graft revealed that the rats treated with the NT-3-loaded sutures had significantly more axons per graft than rats treated with an NT-3 injection and rats without NT-3. These data demonstrate that PNGs serve as scaffolds for axonal growth after SCI and that CaP-coated sutures can efficiently release NT-3 to increase axonal regeneration. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Death with functioning graft in living donor kidney transplantation: analysis of risk factors.

PubMed

El-Agroudy, Amgad E; Bakr, Mohamed A; Shehab El-Dein, Ahmed B; Ghoneim, Mohamed A

2003-01-01

Death with a functioning graft (DWF) has been reported as a major cause of graft loss after renal transplantation. It has been reported to occur in 9-30%. From March 1976 to January 2002, a total of 1400 living donor renal transplants were performed in our center. Out of 257 reported deaths among our patients, 131 recipients died with functioning grafts after a mean period of 53.4 +/- 53.2 months. DWF patients account for 27% of all graft losses in our series. The mean age was 34.9 + 10.6 (range 8-62 years), 98 of them were male and 33 were female. The original kidney disease was GN in 9, PN in 24, PCK in 5 and nephrosclerosis in 8 patients. Acute rejection episodes were diagnosed in 84 patients (63.1). The post-transplant complications encountered were hypertension in 78 patients (59.5%), diabetes mellitus in 30 patients (22.9%), medical infections in 68 (51.5%), hepatic complications in 30 (22.9%) and malignancy in 17 patients (13%). The main causes of death in these patients were infections in 46 (35.6%), cardiovascular in 23 (17.6%), liver cell failure in 15 patients (11.4%) and malignancy in 8 (6.1%). The mean serum creatinine was 2 +/- 0.6 mg/dl at last follow-up before death. We conclude that the relatively higher mortality in renal transplantation is, in part, due to co-morbid medical illness, pre-transplant dialysis treatment, and factors uniquely related to transplantation, including immunosuppression and other drug effects. DWF must be in consideration when calculating graft survival. Copyright 2003 S. Karger AG, Basel

Transplanting Sensitized Kidney Transplant Patients With Equivalent Outcomes Utilizing Stringent HLA Crossmatching.

PubMed

Rohan, Vinayak S; Taber, David J; Moussa, Omar; Pilch, Nicole A; Denmark, Signe; Meadows, Holly B; McGillicuddy, John W; Chavin, Kenneth D; Baliga, Prabhakar K; Bratton, Charles F

2017-02-01

Elevated panel reactive antibody levels have been traditionally associated with increased acute rejection rate and decreased long-term graft survival after kidney transplant. In this study, our objective was to determine patient and allograft outcomes in sensitized kidney transplant recipients with advanced HLA antibody detection and stringent protein sequence epitope analyses. This was a subanalysis of a prospective, risk-stratified randomized controlled trial that compared interleukin 2 receptor antagonist to rabbit antithymocyte globulin induction in 200 kidney transplant recipients, examining outcomes based on panel reactive antibody levels of < 20% (low) versus ≥ 20% (high, sensitized). The study was conducted between February 2009 and July 2011. All patients underwent solid-phase single antigen bead assays to detect HLA antibodies and stringent HLA epitope analyses with protein sequence alignment for virtual crossmatching. Delayed graft function, acute rejection rates, and graft loss were the main outcomes measured. Both the low (134 patients) and high (66 patients) panel reactive antibody level cohorts had equivalent induction and maintenance immunosuppression. Patients in the high-level group were more likely to be female (P < .001), African American (P < .001), and received a kidney from a deceased donor (P = .004). Acute rejection rates were similar between the low (rate of 8%) and high (rate of 9%) panel reactive antibody groups (P = .783). Delayed graft function, borderline rejection, graft loss, and death were not different between groups. Multivariate analyses demonstrated delayed graft function to be the strongest predictor of acute rejection (odds ratio, 5.7; P = .005); panel reactive antibody level, as a continuous variable, had no significant correlation with acute rejection (C statistic, 0.48; P = .771). Appropriate biologic matching with single antigen bead assays and stringent epitope analyses provided excellent outcomes in sensitized patients regardless of the induction therapy choice.

The Current Status of Islet Transplantation and its Perspectives

PubMed Central

Kobayashi, Naoya

2008-01-01

Transplantation of human pancreatic isolated islets can restore beta-cell function but it requires chronic immunosuppression. The outcome of islet transplantation mainly depends on both the quality of islet preparations, and the survival of the graft. The quality of islet preparations can be evaluated by the results of isolation, which determines the chance to achieve insulin independence. The survival of islet grafts is reflected by the amount of engrafted functional tissue that maintains metabolic control. Immunosuppressive therapy prevents the immunological rejection of grafts, but impairs their function and impedes their regenerative capacity. Therefore, the selection of high quality islet preparations and the reduction of toxic effects of immunosuppressive regimens might dramatically improve the outcomes. The application of stem cell therapy in islet transplantation may contribute to a better understanding of the mechanisms responsible for tissue homeostasis and immune tolerance. Xenogeneic islets may serve as an unlimited source if immune tolerance can be achieved. This may be a strategy to enable a substantial improvement in function while overcoming potentially deleterious risks. PMID:19099085

A silk-based encapsulation platform for pancreatic islet transplantation improves islet function in vivo.

PubMed

Hamilton, Diana C; Shih, Hank H; Schubert, Richard A; Michie, Sara A; Staats, Paul N; Kaplan, David L; Fontaine, Magali J

2017-03-01

The success of pancreatic islet (PI) transplantation is challenged by PI functional damage during the peritransplantation period. A silk-based encapsulation platform including mesenchymal stromal cells (MSCs) was evaluated for islet cell delivery in vivo. Islet equivalents (IEQs) were transplanted into the epididymal fat pads of mice with streptozotocin-induced diabetes. Three PI combinations were tested: (A) co-encapsulated in silk with MSCs; (b) encapsulated in silk alone; or (c) pelleted. Blood glucose levels were monitored and intraperitoneal glucose tolerance test (IPGTT) was performed upon return to euglycaemia. Grafts were removed for histology and cytokine content analysis. Mice with PI grafts in silk showed a prompt return to euglycaemia. IPGTT was significantly improved with PI in silk with MSCs, compared to PI in silk alone or pelleted. Both Th 1 and Th 2 cytokines were increased in PI grafts in silk, but Th 1 cytokines were decreased significantly with PI and MSC co-encapsulation. Histological analysis showed osteogenesis and chondrogenesis in the silk grafts containing MSCs. Future studies will evaluate MSC stability and function in vivo and improve silk biocompatibility for applications in islet transplantation. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Behavior of grafted polymers on nanofillers and their influence on polymer nanocomposite properties

NASA Astrophysics Data System (ADS)

Dukes, Douglas Michael

Polymer nanocomposites continue to receive wide-spread acclaim for their potential to improve composite materials beyond conventional macroscale fillers. The improvement lies both in the altered properties of the particle itself and in the interaction region surrounding the filler. As the surface area of the filler increases, a greater volume fraction of this interphase region is present in the composite. However, simply minimizing the particle size to maximize surface area introduces additional problems; the larger specific surface area promotes aggregation to reduce the surface energy. Since the composite's properties are largely tied to the morphology, aggregation prevents control over the dispersion state of the filler, and thus the properties. Therefore, disaggregation and morphology control are vital to achieving designable nanocomposites. To accomplish both tasks, this thesis focuses on the behavior of grafted polymer coatings on nanoparticles and their in uence on the macroscopic properties. Grafted chains play an integral role in both morphology control and reinforcement. To investigate the behavior of polymer brushes on nanoparticles, polystyrene was grafted on 15 nm silica particles at varying graft densities and molecular weights. Dynamic light scattering studies in dilute solution were performed to obtain the brush height as a function of both graft density and molecular weight. Three distinct regimes of behavior exist, the "mushroom", the semi-dilute polymer brush (SDPB), and the concentrated polymer brush (CPB) regimes. In the CPB regime, which is an extraordinary configuration of highly-stretched chains on densely grafted surfaces, the brush height h was found to scale as h ∝ N4/5, where N is the degree of polymerization. This result is contrary to the observed scaling of the CPB in flat interface systems, where h ∝ N1. To explore the behavior of grafted chains in the melt, molecular dynamics simulations were performed on grafted nanoparticles grafted with varying amounts of polymer chains at different curvatures. Particles as small as 15 monomers in size were found to already be in the large particle limit, a result that has many implications regarding the dispersibility of grafted fillers in composites. At low graft densities, melt chains were found to form entanglements with the brush all the way to the particle surface, implying the particle is not effectively screened by the grafted chains. The mechanical properties of these grafted silica composites were studied as a function of matrix polymer fraction. As more matrix polymer is introduced, the dominant contribution to the behavior shifts from the grafted chains to the matrix chains. This elucidates the role of grafted chains on the mechanical properties of grafted nanoparticle composites. As the graft density is increased, the wettability of grafted chains was shown to decrease, causing fewer entanglements between grafted chains and matrix chains, resulting in poorer reinforcement. Interesting behavior was observed at low graft densities; a pronounced shape memory effect occurred at high particle concentrations. It is proposed that the grafted chains entangle with adjacent grafted chains, forming a three-dimensional network of entangled brushes attached to silica cores. This structure effectively forms "cross-links" as in elastomeric systems, giving an entropic restorative force to stretched chains. Thus, above Tg, when chains have a higher degree of mobility, the composites can be stretched to over 800%. When cooled to below Tg, they retain the deformed geometry. Upon reheating above Tg, the composite is restored to its original dimensions. This work has identified means of improving theoretical models to better guide future experiments and lead to predictability in polymer composite design. Grafted chains have the demonstrated ability to control the morphology and reinforcement in polymer composites. The behavior of grafted chains were shown to demonstrate drastically different properties from their bulk polymer counterparts.

Volumetry-based selection of right posterior sector grafts for adult living donor liver transplantation.

PubMed

Kim, Bong-Wan; Xu, Weiguang; Wang, Hee-Jung; Park, Yong-Keun; Lee, Kwangil; Kim, Myung-Wook

2011-09-01

To determine the feasibility of volumetric criteria without anatomic exclusion for the selection of right posterior sector (RPS) grafts for adult-to-adult living donor liver transplantation (LDLT), we reviewed and compared our transplant data for RPS grafts and right lobe (RL) grafts. Between January 2008 and September 2010, adult-to-adult LDLT was performed 65 times at our institute; 13 of the procedures (20%) were performed with RPS grafts [the posterior sector (PS) group], and 39 (60%) were performed with RL grafts (the RL group). The volumetry of the 13 RPS donor livers showed that the RPS volume was 39.8% ± 7.6% of the total liver volume. Ten of the 13 donors had to donate RPS grafts because the left liver volume was inadequate. All donor procedures were performed successfully, and all donors recovered from hepatectomy. However, longer operative times were required for the procurement of RPS grafts versus RL grafts (418 ± 40 versus 345 ± 48 minutes, P < 0.001). The postoperative recovery of liver function was smoother for the donors of the PS group versus the donors of the RL group. The RPS grafts had significantly smaller hepatic artery and bile duct openings than the RL grafts. All recipients with RPS grafts survived LDLT. No recipients experienced vascular graft complications or small-for-size graft dysfunction. There were no significant differences in the incidence of posttransplant complications between the donors and recipients of the PS and RL groups. The 3-year graft survival rates were favorable in both groups (100% in the PS group versus 91% in the RL group). In conclusion, the selection of RPS grafts by volume criteria is a feasible strategy for an adult-to-adult LDLT program. Copyright © 2011 American Association for the Study of Liver Diseases.

Hydroxyapatite crystals as a bone graft substitute in benign lytic lesions of bone

PubMed Central

Gupta, Anil Kumar; Kumar, Praganesh; Keshav, Kumar; Singh, Anant

2015-01-01

Background: Bone grafts are required to fill a cavity created after curettage of benign lytic lesions of the bone. To avoid the problems associated at donor site with autologous bone graft, we require allograft or bone graft substitutes. We evaluated the healing of lytic lesions after hydroxyapatite (HA) grafting by serial radiographs. Materials and Methods: Forty cases of benign lytic lesions of bone were managed by simple curettage and grafting using HA blocks. Commercially available HA of bovine origin (Surgiwear Ltd., Shahjahanpur, India) was used for this purpose. Mean duration of followup was 34.8 months (range 12–84 months). Mean patient age was 19.05 years (range 3–55 years). Radiological staging of graft incorporation was done as per criteria of Irwin et al. 2001. Results: In our series, two cases were in stage I. A total of 11 cases were in stage II and 27 were in stage III. Graft incorporation was radiologically complete by 15 months. Clinical recovery was observed before radiological healing. The average time taken to return to preoperative function was 3 months. Recurrence was observed in giant cell tumor (n = 3) and chondromyxoid fibroma (n = 1). There was no incidence of graft rejection, collapse, growth plate disturbances or antigenic response. Conclusions: We conclude that calcium HA is biologically acceptable bone graft substitute in the management of benign lytic lesions of bone. PMID:26806973

Comparative transcriptome profiling of chilling stress responsiveness in grafted watermelon seedlings.

PubMed

Xu, Jinhua; Zhang, Man; Liu, Guang; Yang, Xingping; Hou, Xilin

2016-12-01

Rootstock grafting may improve the resistance of watermelon plants to low temperatures. However, information regarding the molecular responses of rootstock grafted plants to chilling stress is limited. To elucidate the molecular mechanisms of chilling tolerance in grafted plants, the transcriptomic responses of grafted watermelon under chilling stress were analyzed using RNA-seq analysis. Sequencing data were used for digital gene expression (DGE) analysis to characterize the transcriptomic responses in grafted watermelon seedlings. A total of 702 differentially-expressed genes (DEGs) were found in rootstock grafted (RG) watermelon relative to self-grafted (SG) watermelon; among these genes, 522 genes were up-regulated and 180 were down-regulated. Additionally, 164 and 953 genes were found to specifically expressed in RG and SG seedlings under chilling stress, respectively. Functional annotations revealed that up-regulated DEGs are involved in protein processing, plant-pathogen interaction and the spliceosome, whereas down-regulated DEGs are associated with photosynthesis. Moreover, 13 DEGs were randomly selected for quantitative real time PCR (qRT-PCR) analysis. The expression profiles of these 13 DEGs were consistent with those detected by the DGE analysis, supporting the reliability of the DGE data. This work provides additional insight into the molecular basis of grafted watermelon responses to chilling stress. Copyright © 2016. Published by Elsevier Masson SAS.

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

NASA Astrophysics Data System (ADS)

Roghani-Mamaqani, Hossein; Khezri, Khezrollah

2016-01-01

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

Basiliximab versus daclizumab combined with triple immunosuppression in deceased donor renal graft recipients.

PubMed

Grego, K; Arnol, M; Bren, A F; Kmetec, A; Tomaziĉ, J; Kandus, A

2007-12-01

In this prospective, randomized, open-label, single-center study, we compared the efficacy and safety of two anti-interleukin-2 receptor monoclonal antibodies among adult recipients of at least 1 HLA-mismatched deceased donor renal grafts. Eligible patients were randomized to induction with either basiliximab or daclizumab. Both groups received cyclosporine microemulsion (CsA Neoral), mycophenolate mofetil, and methylprednisolone. An intent-to-treat analysis of 1-year data assessed the incidence of acute rejection episodes, the renal graft function, the safety, and the patient and graft survivals. Among 127 patients, six (10.0%) and seven (11.5%) patients experienced biopsy-confirmed acute rejection at 12 months, in the basiliximab and the daclizumab groups, respectively. Two renal grafts were lost in the basiliximab and six in the daclizumab cohort, one of them due to rejection. One basiliximab and two daclizumab patients died. Hospital treatment was required for 25 and 33 infections in basiliximab and daclizumab groups, respectively. One basal cell carcinoma of skin was detected. One hypersensitivity reaction was observed with daclizumab. At 12 months, serum creatinine was 101+/-28 micromol/L with basiliximab and 109+/-41 micromol/L with daclizumab. Patient survival was 98.4% with basiliximab and 96.7% with daclizumab, and graft survival was 96.8% versus 90.8%, respectively. No significant differences were observed between the groups. Basiliximab or daclizumab combined with triple therapy was an efficient and safe immunosuppression strategy, demonstrated with low incidence of acute rejection episodes, an acceptable adverse event profile, excellent graft function, and high survival rates in adult recipients within the first year after deceased donor renal transplantation.

Peri-Implant Tissue Findings in Bone Grafted Oral Cancer Patients Compared to non Bone Grafted Patients without Oral Cancer

PubMed Central

Agata, Hideki; Sándor, George K.; Haimi, Suvi

2011-01-01

ABSTRACT Objectives The aim of this study was to compare microbiological, histological, and mechanical findings from tissues around osseointergrated dental implants in patients who had undergone tumour resection and subsequent bone grafting with non bone grafted patients without a history of oral cancer and to develop an effective tool for the monitoring of the peri-implant tissues. A third aim was to assess and compare the masticatory function of the two patient groups after reconstruction with dental implants. Material and Methods A total of 20 patients were divided into 2 groups. The first group was edentulous and treated with dental implants without the need for bone grafting. The second edentulous group, with a history of oral cancer involving the mandible, received onlay bone grafts with concurrent placement of dental implants. Microbiological, histological, mechanical and biochemical assessment methods, crevicular fluid flow rate, hygiene-index, implant mobility, and the masticatory function were analysed and compared in both patient groups. Results The microbiological examinations showed no evidence of the three most common pathogenic bacteria: Porphyromonas gingivalis, Prevotella intermedius, Actinobacillus actinomycetencomitans. A causal relationship between specific microbes and peri-implant inflammation could not be found. All biopsies in both patient groups revealed early signs of soft tissue peri-implant inflammation. Conclusions The crevicular fluid volume and grade of gingival inflammation around the dental implants were related. Peri-implant tissue findings were similar in the two patient groups despite the history of oral cancer and the need for bone grafting at the time of dental implant placement. PMID:24421999

Fabrication and preliminary study of a biomimetic tri-layer tubular graft based on fibers and fiber yarns for vascular tissue engineering.

PubMed

Wu, Tong; Zhang, Jialing; Wang, Yuanfei; Li, Dandan; Sun, Binbin; El-Hamshary, Hany; Yin, Meng; Mo, Xiumei

2018-01-01

Designing a biomimetic and functional tissue-engineered vascular graft has been urgently needed for repairing and regenerating defected vascular tissues. Utilizing a multi-layered vascular scaffold is commonly considered an effective way, because multi-layered scaffolds can easily simulate the structure and function of natural blood vessels. Herein, we developed a novel tri-layer tubular graft consisted of Poly(L-lactide-co-caprolactone)/collagen (PLCL/COL) fibers and Poly(lactide-co-glycolide)/silk fibroin (PLGA/SF) yarns via a three-step electrospinning method. The tri-layer vascular graft consisted of PLCL/COL aligned fibers in inner layer, PLGA/SF yarns in middle layer, and PLCL/COL random fibers in outer layer. Each layer possessed tensile mechanical strength and elongation, and the entire tubular structure provided tensile and compressive supports. Furthermore, the human umbilical vein endothelial cells (HUVECs) and smooth muscle cells (SMCs) proliferated well on the materials. Fluorescence staining images demonstrated that the axially aligned PLCL/COL fibers prearranged endothelium morphology in lumen and the circumferential oriented PLGA/SF yarns regulated SMCs organization along the single yarns. The outside PLCL/COL random fibers performed as the fixed layer to hold the entire tubular structure. The in vivo results showed that the tri-layer vascular graft supported cell infiltration, scaffold biodegradation and abundant collagen production after subcutaneous implantation for 10weeks, revealing the optimal biocompatibility and tissue regenerative capability of the tri-layer graft. Therefore, the specially designed tri-layer vascular graft will be beneficial to vascular reconstruction. Copyright © 2017. Published by Elsevier B.V.

Outcomes and complications following graft reconstruction for anterior sternoclavicular joint instability.

PubMed

Willinger, Lukas; Schanda, Jakob; Herbst, Elmar; Imhoff, Andreas B; Martetschläger, Frank

2016-12-01

Publications describing tendon graft reconstruction for anterior sternoclavicular joint (SCJ) instability are rare and usually refer to small patient numbers. The aim of this study was to systematically review the literature regarding outcomes and complications following tendon graft reconstruction techniques for anterior SCJ instability. An online database was systematically searched to identify studies on graft reconstruction for anterior SCJ instability. Reported outcome scores were graded as excellent, good, fair and poor to summarize the study results. All reported complications were recorded. Five articles with a total of 80 patients met the inclusion criteria. Reported outcomes were excellent in 10 %, good in 89 % and fair in 1 %. Recurrent instability was found in 10 % of the patients, and 5 % underwent revision surgery due to persistent impairment of shoulder function related to SCJ instability or osteoarthritis. Surgical stabilization techniques for the SCJ using autologous tendon grafts have shown to be safe and reliable and make better patients' pain situation and shoulder function. However, a certain amount of impairment might persist, which needs to be discussed with patients. Severe complications were rare and revision rates were as low as 5 %. Therefore, graft reconstruction techniques should be considered for patients with chronic anterior SCJ instability after a course of failed conservative treatment. This study is valuable for clinicians in daily clinical practice when dealing with this difficult-to-treat pathology and can help surgeons to better predict the clinical outcomes and complications following SCJ graft reconstruction. It should, however, not lead to underestimation of the potential risks of the procedure. Systematic review, Level IV.

Association of a coding polymorphism in Fc gamma receptor 2A and graft survival in re-transplant candidates.

PubMed

Arnold, Marie-Luise; Fuernrohr, Barbara G; Weiß, Katrin M; Harre, Ulrike; Wiesener, Michael S; Spriewald, Bernd M

2015-10-01

The family of Fc gamma receptors (FcγRs) is involved in mediating immunological effector functions. FcγRs are differentially expressed on immune cells and can act either activating or inhibitory, with FcγR2A belonging to the first group. The polymorphism H131R (rs1801274) in FCGR2A has been associated with acute rejection and can shift the overall balance between activating and inhibitory FcγRs. Anti-HLA allo-antibodies in transplant recipients have been identified as risk factor for organ survival after transplantation. In this study we genotyped FCGR2A H131R in 200 patients who had undergone kidney transplantation and experienced loss of graft function. FCGR2A polymorphism was related to graft survival and anti-HLA antibodies. Graft survival was calculated as the time interval between transplantation and return to chronic dialysis after transplantation. The gene frequency of FCGR2A R/R131 was found significantly more often in patients with earlier (⩽60months) compared to patients with later (>60months) graft failure. Overall patients homozygous for R/R131 had a significantly shorter graft survival, compared to H/H131 or H/R131 which is even more pronounced, when anti-HLA antibodies were present. These data suggest, that FCGR2A polymorphisms constitute a risk factor for graft loss following kidney transplantation and that this effect is related to anti-HLA antibodies. Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Effect of donor/recipient body weight mismatch on patient and graft outcome in living-donor kidney transplantation.

PubMed

el-Agroudy, Amgad E; Hassan, Nabil A; Bakr, Mohamed A; Foda, Mohamed A; Shokeir, Ahmed A; Shehab el-Dein, Ahmed B

2003-01-01

There have been conflicting reports showing that kidneys from small donors may be at risk for graft loss if they are transplanted into large recipients. The aim of this work was to examine the donor/recipient body weight ratio (D/RBWR) on patient and graft outcome. During the period from January 1990 to January 2002, 856 kidney transplants were performed. Of these, 776 kidney transplant recipients were selected after exclusion of pediatric, second transplant patients and those with a body mass index of 35. All patients achieved a minimum follow-up of 1-year. According to D/RBWR, patients were divided into 3 groups: low (0.9), medium (0.91-1.2) and high (1.2). Data were collected on graft function, acute and chronic rejection, post-transplant complications, and 1- and 5-year graft and patient survival. There was a statistically significant increase in the incidence of chronic rejection, post-transplant hypertension and diabetes mellitus in the low group. The incidence and frequency of acute rejection episodes were nearly the same in the 3 groups. Graft function, estimated by serum creatinine at 1 year, was significantly lower in the low group. The 5-year graft and patient survival was 71, 80, 88 and 81, 85 and 92%, in the low, medium and high groups, respectively. We conclude that a low D/RBWR may contribute to inferior long-term renal allograft survival. The hyperfiltration hypothesis due to low nephron mass in the low D/RBWR group may explain these findings.

[Simultaneous Hepatorenal Transplantation from a Brain-Dead Donor for Graft Dysfunction and Renal Insufficiency in a Liver Transplant Recipient : A Case Report].

PubMed

Takada, Hideaki; Kobayashi, Takashi; Ogawa, Kohei; Miyata, Hitomi; Sawada, Atsuro; Akamatsu, Shusuke; Negoro, Hiromitsu; Saito, Ryoichi; Terada, Naoki; Yamasaki, Toshinari; Inoue, Takahiro; Teramoto, Yuki; Shibuya, Shinsuke; Haga, Hironori; Kaido, Toshimi; Uemoto, Shinji; Ogawa, Osamu

2017-08-01

We report a case of lethal hepatorenal insufficiency in a 52-year-old man who received successful simultaneous hepatorenal transplantation from a deceased donor. The patient had undergone live-donor liver transplantation for type-C hepatitis and liver cirrhosis 11 years before he developed graft liver dysfunction due to recurrent viral hepatitis and cirrhosis. At that instance, he also developed end-stage renal dysfunction due to calcineurin inhibitor nephropathy and hepatorenal syndrome. Although he needed three open hemostases and abundant blood transfusion, he was withdrawn from continuous hemodiafiltration on the 55th day and discharged from the hospital on the 272nd day postoperatively. Simultaneous hepatorenal transplantation was reported to be associated with more favorable outcomes of graft function, lower rejection rates, but higher perioperative complication rates compared with liver transplantation alone in patients on hemodialysis. Particularly, close attention should be paid for hemostasis since patients have a hemorrhagic tendency until the recovery of graft liver function.

Enhancement of interfacial adhesion between starch and grafted poly(ε-caprolactone).

PubMed

Ortega-Toro, Rodrigo; Santagata, Gabriella; Gomez d'Ayala, Giovanna; Cerruti, Pierfrancesco; Talens Oliag, Pau; Chiralt Boix, M Amparo; Malinconico, Mario

2016-08-20

The use of a modified poly(ε-caprolactone) (gPCL) to enhance polymer miscibility in films based on thermoplastic starch (S) and poly(ε-caprolactone) is reported. PCL was functionalized by grafting with maleic anyhdride (MA) and/or glycidyl methacrylate (GMA) by reactive blending in a batch mixer. gPCL based materials were analysed in terms of their grafting degree, structural and thermal properties. Blends based on starch and PCL (wt. ratio 80:20) with including gPCL (0, 2.5 and 5wt.%), as a compatibilizer, were obtained by extrusion and compression moulding, and their structural, thermal, mechanical and barrier properties were investigated. Blends containing gPCL evidenced better interfacial adhesion between starch and PCL domains, as deduced from both structural (XRD, FTIR, SEM) and bulk properties (DSC, TGA). Moreover, grafted PCL-based compatibilizers greatly improved functional properties of S-PCL blend films, as pointed out from mechanical performance and higher barrier properties, valuable to meet the food packaging requirements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Local immunomodulation with Fas ligand-engineered biomaterials achieves allogeneic islet graft acceptance.

PubMed

Headen, Devon M; Woodward, Kyle B; Coronel, María M; Shrestha, Pradeep; Weaver, Jessica D; Zhao, Hong; Tan, Min; Hunckler, Michael D; Bowen, William S; Johnson, Christopher T; Shea, Lonnie; Yolcu, Esma S; García, Andrés J; Shirwan, Haval

2018-06-04

Islet transplantation is a promising therapy for type 1 diabetes. However, chronic immunosuppression to control rejection of allogeneic islets induces morbidities and impairs islet function. T effector cells are responsible for islet allograft rejection and express Fas death receptors following activation, becoming sensitive to Fas-mediated apoptosis. Here, we report that localized immunomodulation using microgels presenting an apoptotic form of the Fas ligand with streptavidin (SA-FasL) results in prolonged survival of allogeneic islet grafts in diabetic mice. A short course of rapamycin treatment boosted the immunomodulatory efficacy of SA-FasL microgels, resulting in acceptance and function of allografts over 200 days. Survivors generated normal systemic responses to donor antigens, implying immune privilege of the graft, and had increased CD4 + CD25 + FoxP3 + T regulatory cells in the graft and draining lymph nodes. Deletion of T regulatory cells resulted in acute rejection of established islet allografts. This localized immunomodulatory biomaterial-enabled approach may provide an alternative to chronic immunosuppression for clinical islet transplantation.

Chemically grafted carbon-coated LiFePO4 using diazonium chemistry

NASA Astrophysics Data System (ADS)

Delaporte, Nicolas; Perea, Alexis; Amin, Ruhul; Zaghib, Karim; Bélanger, Daniel

2015-04-01

The effect of surface functionalization of aminophenyl and bromophenyl groups on carbon-coated LiFePO4 and the electrochemical properties of composite electrode containing these materials are reported. The functionalization was performed by spontaneous reduction of the corresponding in situ generated diazonium ions. The resulting chemically grafted LiFePO4/C materials were characterized by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. XRD analyses indicated the cathode material was partially oxidized. Thermogravimetric and elemental analyses revealed the loading of grafted molecules was between 0.2 and 1.1 wt.% depending on the reaction conditions. Interestingly, the electrochemical performances of the modified LiFePO4/C are not adversely affected by the presence of either aminophenyl and bromophenyl groups at the carbon surface, and in fact the grafted LiFePO4/C displayed slightly superior discharge capacity at the highest C rate investigated for a low loading of organic molecules.

Improvement of thermal conductivities for silicone nanocomposite via incorporating poly(γ-methacryloxypropyltrimethoxy silane) grafted graphene fillers

NASA Astrophysics Data System (ADS)

Chen, Tian; Liu, Bo

2018-02-01

The proposed grafting polymerization of γ-methacryloxypropyltrimethoxy silane was performed to functionalize graphene, aiming to fabricate functionalized graphene/silicone with excellent thermal conductivities. The surface morphology and element content of poly(γ-methacryloxypropyltrimethoxy silane) grafted reduced graphene oxide (g-RGO) was characterized by Atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). The usage of g-RGO was benefit for improving the thermal conductivity of silicone (SI). The g-RGO/SI (2 wt% filler) had thermal conductivity of 1.31 W·m-1·K-1 and thermal diffusivity of 1.08 mm2·s-1 (increased by 620% compared to that of SI), which held potential for electronic packaging materials and micro-electro-mechanical systems apparatus.

Pretransplant soluble CD30 serum concentration does not affect kidney graft outcomes 3 years after transplantation.

PubMed

Kovač, J; Arnol, M; Vidan Jeras, B; Bren, A F; Kandus, A

2010-12-01

An elevated serum concentration of soluble the form of CD30 (sCD30), an activation marker of mainly T(H)2-type cytokines producing T lymphocytes, has been reported as a predictive factor for acute cellular rejection episodes and poor graft outcomes in kidney transplantation. This historic cohort study investigated the association of a pretransplant sCD30 serum concentrations with kidney graft function and graft survival 3 years posttransplantation in adult recipients of deceased donor kidney grafts, treated with monoclonal anti-CD25 antibodies as an induction treatment combined with a cyclosporine (CsA)-based maintenance triple therapy. The pretransplant sera of 296 recipients were tested for sCD30 content using a microsphere flow-cytometry assay. The estimated glomerular filtration rate (eGFR) was determined by the 4-variable Modification of Diet in Renal Disease equation. The incidences of graft loss were calculated with the use of Kaplan-Meier survival analysis and compared using the log-rank test. According to the distribution of the pretransplant sCD30 levels concentration ≥2700 pg/mL was defined as high (n = 146) and concentration <2700 pg/mL as low (n = 150). Three years posttransplantation, the eGFR was not significantly different in the recipients in high and low sCD30 groups (65 ± 24 vs 67 ± 21 mL/min/1.73 m(2); P = .43); there was no association between the eGFR 3 years after transplantation and the pretransplant sCD30 levels (r(2) = 0.002; P = .49). Graft survival 3 years after transplantation was also not different in the recipients in high and low sCD30 groups (P = .52). In our adult deceased-donor kidney graft recipients, the pretransplant sCD30 serum concentration was not a predictive factor of immunologic risk associated with the kidney graft function 3 years posttransplantation; neither did it affect graft survival 3 years after transplantation. The immunosuppression with anti-CD25 antibodies as an induction treatment combined with the CsA-based maintenance triple therapy could possibly be decisive for our findings. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of Aerobic Exercise Applied Early After Coronary Artery Bypass Grafting on Pulmonary Function, Respiratory Muscle Strength, and Functional Capacity: A Randomized Controlled Trial.

PubMed

Borges, Daniel L; Silva, Mayara Gabrielle; Silva, Luan Nascimento; Fortes, João Vyctor; Costa, Erika Thalita; Assunção, Rebeca Pessoa; Lima, Carlos Magno; da Silva Nina, Vinícius José; Bernardo-Filho, Mário; Caputo, Danúbia Sá

2016-09-01

Physical activity is beneficial in several clinical situations and recommended for patients with ischemic heart disease, as well as for those undergoing cardiac surgery. In a randomized controlled trial, 34 patients underwent coronary artery bypass grafting. A randomized control group (n = 15) submitted to conventional physiotherapy. The intervention group (n = 19) received the same protocol plus additional aerobic exercise with cycle ergometer. Pulmonary function by spirometry, respiratory muscle strength by manovacuometry, and functional capacity through 6-minute walking test was assessed before surgery and at hospital discharge. There was significant reduction in pulmonary function in both groups. In both groups, inspiratory muscle strength was maintained while expiratory muscle strength significantly decreased. Functional capacity was maintained in the intervention group (364.5 [324.5 to 428] vs. 348 [300.7 to 413.7] meters, P = .06), but it decreased significantly in control group patients (320 [288.5 to 393.0] vs. 292 [237.0 to 336.0] meters, P = .01). A significant difference in functional capacity was also found in intergroup analyses at hospital discharge (P = .03). Aerobic exercise applied early on coronary artery bypass grafting patients may promote maintenance of functional capacity, with no impact on pulmonary function and respiratory muscle strength when compared with conventional physiotherapy.

Tissue-engineered lymphatic graft for the treatment of lymphedema

PubMed Central

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

2015-01-01

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

Blood Vessels in Allotransplantation.

PubMed

Abrahimi, P; Liu, R; Pober, J S

2015-07-01

Human vascularized allografts are perfused through blood vessels composed of cells (endothelium, pericytes, and smooth muscle cells) that remain largely of graft origin and are thus subject to host alloimmune responses. Graft vessels must be healthy to maintain homeostatic functions including control of perfusion, maintenance of permselectivity, prevention of thrombosis, and participation in immune surveillance. Vascular cell injury can cause dysfunction that interferes with these processes. Graft vascular cells can be activated by mediators of innate and adaptive immunity to participate in graft inflammation contributing to both ischemia/reperfusion injury and allograft rejection. Different forms of rejection may affect graft vessels in different ways, ranging from thrombosis and neutrophilic inflammation in hyperacute rejection, to endothelialitis/intimal arteritis and fibrinoid necrosis in acute cell-mediated or antibody-mediated rejection, respectively, and to diffuse luminal stenosis in chronic rejection. While some current therapies targeting the host immune system do affect graft vascular cells, direct targeting of the graft vasculature may create new opportunities for preventing allograft injury and loss. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

Nanoparticle stability in semidilute and concentrated polymer solutions.

PubMed

Dutta, Nupur; Green, David

2008-05-20

The wetting of PDMS-grafted silica spheres (PDMS- g-silica) is connected to their depletion restabilization in semidilute and concentrated PDMS/cyohexane polymer solutions. Specifically, we found that a wetting diagram of chemically identical graft and free homopolymers predicts stability of hard, semisoft, and soft spheres as a function of the bulk free polymer volume fraction, graft density, and the graft and free polymer chain lengths. The transition between stable and aggregated regions is determined optically and with dynamic light scattering. The point of demarcation between the regions occurs when the graft and free polymer chains are equal in length. When graft chains are longer than free chains, the particles are stable; in contrast, the particles are unstable when the opposite is true. The regions of particle stability and instability are corroborated with theoretical self-consistent mean-field calculations, which not only show that the grafted brush is responsible for particle dispersion in the complete wetting region but also aggregation in the incomplete wetting region. Ultimately, our results indicate that depletion restabilization depends on the interfacial properties of the nanoparticles in semidilute and concentrated polymer solutions.

Phase behaviors of supramolecular graft copolymers with reversible bonding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xu; Wang, Liquan, E-mail: jlin@ecust.edu.cn, E-mail: lq-wang@ecust.edu.cn; Jiang, Tao

2013-11-14

Phase behaviors of supramolecular graft copolymers with reversible bonding interactions were examined by the random-phase approximation and real-space implemented self-consistent field theory. The studied supramolecular graft copolymers consist of two different types of mutually incompatible yet reactive homopolymers, where one homopolymer (backbone) possesses multifunctional groups that allow second homopolymers (grafts) to be placed on. The calculations carried out show that the bonding strength exerts a pronounced effect on the phase behaviors of supramolecular graft copolymers. The length ratio of backbone to graft and the positions of functional groups along the backbone are also of importance to determine the phase behaviors.more » Phase diagrams were constructed at high bonding strength to illustrate this architectural dependence. It was found that the excess unbounded homopolymers swell the phase domains and shift the phase boundaries. The results were finally compared with the available experimental observations, and a well agreement is shown. The present work could, in principle, provide a general understanding of the phase behaviors of supramolecular graft copolymers with reversible bonding.« less

Experimental design and analysis of activators regenerated by electron transfer-atom transfer radical polymerization experimental conditions for grafting sodium styrene sulfonate from titanium substrates.

PubMed

Foster, Rami N; Johansson, Patrik K; Tom, Nicole R; Koelsch, Patrick; Castner, David G

2015-09-01

A 2 4 factorial design was used to optimize the activators regenerated by electron transfer-atom transfer radical polymerization (ARGET-ATRP) grafting of sodium styrene sulfonate (NaSS) films from trichlorosilane/10-undecen-1-yl 2-bromo-2-methylpropionate (ester ClSi) functionalized titanium substrates. The process variables explored were: (1) ATRP initiator surface functionalization reaction time; (2) grafting reaction time; (3) CuBr 2 concentration; and (4) reducing agent (vitamin C) concentration. All samples were characterized using x-ray photoelectron spectroscopy (XPS). Two statistical methods were used to analyze the results: (1) analysis of variance with [Formula: see text], using average [Formula: see text] XPS atomic percent as the response; and (2) principal component analysis using a peak list compiled from all the XPS composition results. Through this analysis combined with follow-up studies, the following conclusions are reached: (1) ATRP-initiator surface functionalization reaction times have no discernable effect on NaSS film quality; (2) minimum (≤24 h for this system) grafting reaction times should be used on titanium substrates since NaSS film quality decreased and variability increased with increasing reaction times; (3) minimum (≤0.5 mg cm -2 for this system) CuBr 2 concentrations should be used to graft thicker NaSS films; and (4) no deleterious effects were detected with increasing vitamin C concentration.

[Effect of free and polymer carrier encapsulated doxorubicin towards HCT116 cells of human colorectal carcinoma].

PubMed

Sen'kiv, Iu V; Heffeter, P; Riabtseva, A O; Boĭko, N M; Mitina, N Ie; Zaichenko, O S; Berger, W; Stoĭka, R S

2013-01-01

Development of novel nanoscale functionalized carriers is nowadays one of the most urgent problems in cancer treatment. The aim of our study was to compare the antineoplastic effect of free doxorubicin and its complex with a nanoscale polymeric carrier towards HTC116 colorectal carcinoma cells. It was established that application of the complex of poly(5-tret-butylperoxy)-5-methyl-1-hexene-3-in-co-glycydyl metacrylat)-graft-polyethyleneglycol (poly(VEP-GMA-PEG)-graft-PEG), where VEP--5-tret-butylperoxy)-5-methyl-1-hexene-3-in; GMA--glycydyl metacrylat; graft-PEG--graft-polyethyleneglycol accordingly, functionalized with phosphatidylcholine for doxorubicin delivery increased 10 times the efficiency of cytotoxic action of this drug, as compared wich such efficiency in case of the action of free doxorubicin. The encapsulated form of doxorubicin caused more intensive cleavage of the reparation enzyme PARP and longer delay in G2/M cell cycle arrest, compared to such effects of free doxorubicin. The developed carrier itself is non-toxic to the used mammalian cells and does not cause impairment in their cell cycle. A deletion in both alleles of p53 gene did not affect the antineoplastic action of doxorubicin that was immobilized on the nanoscale carrier. Thus, p53-dependent signaling pathways are not involved in the cytotoxic action of doxorubicin-carrier complex. It is suggested that novel nanoscale polymeric carrier poly(VEP-GMA-PEG)-graft-PEG functionalized with phosphatidylcholine could be a promising carrier for targeted delivery of anticancer drugs.

Historical perspective of cell transplantation in Parkinson’s disease

PubMed Central

Boronat-García, Alejandra; Guerra-Crespo, Magdalena; Drucker-Colín, René

2017-01-01

Cell grafting has been considered a therapeutic approach for Parkinson’s disease (PD) since the 1980s. The classical motor symptoms of PD are caused by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to a decrement in dopamine release in the striatum. Consequently, the therapy of cell-transplantation for PD consists in grafting dopamine-producing cells directly into the brain to reestablish dopamine levels. Different cell sources have been shown to induce functional benefits on both animal models of PD and human patients. However, the observed motor improvements are highly variable between individual subjects, and the sources of this variability are not fully understood. The purpose of this review is to provide a general overview of the pioneering studies done in animal models of PD that established the basis for the first clinical trials in humans, and compare these with the latest findings to identify the most relevant aspects that remain unanswered to date. The main focus of the discussions presented here will be on the mechanisms associated with the survival and functionality of the transplants. These include the role of the dopamine released by the grafts and the capacity of the grafted cells to extend fibers and to integrate into the motor circuit. The complete understanding of these aspects will require extensive research on basic aspects of molecular and cellular physiology, together with neuronal network function, in order to uncover the real potential of cell grafting for treating PD. PMID:28698835

Historical perspective of cell transplantation in Parkinson's disease.

PubMed

Boronat-García, Alejandra; Guerra-Crespo, Magdalena; Drucker-Colín, René

2017-06-24

Cell grafting has been considered a therapeutic approach for Parkinson's disease (PD) since the 1980s. The classical motor symptoms of PD are caused by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to a decrement in dopamine release in the striatum. Consequently, the therapy of cell-transplantation for PD consists in grafting dopamine-producing cells directly into the brain to reestablish dopamine levels. Different cell sources have been shown to induce functional benefits on both animal models of PD and human patients. However, the observed motor improvements are highly variable between individual subjects, and the sources of this variability are not fully understood. The purpose of this review is to provide a general overview of the pioneering studies done in animal models of PD that established the basis for the first clinical trials in humans, and compare these with the latest findings to identify the most relevant aspects that remain unanswered to date. The main focus of the discussions presented here will be on the mechanisms associated with the survival and functionality of the transplants. These include the role of the dopamine released by the grafts and the capacity of the grafted cells to extend fibers and to integrate into the motor circuit. The complete understanding of these aspects will require extensive research on basic aspects of molecular and cellular physiology, together with neuronal network function, in order to uncover the real potential of cell grafting for treating PD.

Implant-supported fixed restoration of post-traumatic mandibular defect accompanied with skin grafting: A clinical report

PubMed Central

Noh, Kwantae; Choi, Woo-Jin

2013-01-01

Traumatic defects are mostly accompanied by hard and soft tissue loss. This report describes the surgical and prosthetic treatment of a patient with post-traumatic mandibular defect. A split-thickness skin graft was performed prior to implant placement and prefabricated acrylic stent was placed to hold the graft in place. The esthetic and functional demands of the patient were fulfilled by implant-supported screw-retained fixed prosthesis using CAD-CAM technology. PMID:23508120

[Proven and innovative operative techniques for reanimation of the paralyzed face].

PubMed

Frey, M; Michaelidou, M; Tzou, C-H J; Hold, A; Pona, I; Placheta, E

2010-04-01

This overview on the currently most effective reconstructive techniques for reanimation of the unilaterally or bilaterally paralysed face includes all important techniques of neuromuscular reconstruction as well as of supplementary static procedures, which contribute significantly to the efficiency and quality of the functional overall result. Attention is paid to the best indications at the best time since onset of the facial palsy, depending on the age of the patient, the cause of the lesion, and the compliance of the patient for a long-lasting and complex rehabilitation programme. Immediate neuromuscular reconstruction of mimic function is favourable by nerve suture or nerve grafting of the facial nerve, or by using the contralateral healthy facial nerve via cross-face nerve grafting as long as the time since onset of the irreversible palsy is short enough that the paralysed mimic muscles can still be reinnervated. For the most frequent indication, the unilateral irreversible and complete palsy, a three-stage concept is described including cross-face nerve grafting, free functional gracilis muscle transplantation, and several supplementary procedures. In patients with limited life expectancy, transposition of the masseteric muscles is favoured. Bilateral facial palsy is treated by bilateral free gracilis muscle transplantation with the masseteric nerve branches for motor reinnervation. Functional upgrading in incomplete lesions is achieved by cross-face nerve grafting with distal end-to-side neurorrhaphy or by functional muscle transplantation with ipsilateral facial nerve supply. (c) Georg Thieme Verlag KG Stuttgart-New York.

Embryonic stem cell grafting in normal and infarcted myocardium: serial assessment with MR imaging and PET dual detection.

PubMed

Qiao, Hui; Zhang, Hualei; Zheng, Yuanjie; Ponde, Datta E; Shen, Dinggang; Gao, Fabao; Bakken, Ashley B; Schmitz, Alexander; Kung, Hank F; Ferrari, Victor A; Zhou, Rong

2009-03-01

To use magnetic resonance (MR) imaging and positron emission tomography (PET) dual detection of cardiac-grafted embryonic stem cells (ESCs) to examine (a) survival and proliferation of ESCs in normal and infarcted myocardium, (b) host macrophage versus grafted ESC contribution to serial MR imaging signal over time, and (c) cardiac function associated with the formation of grafts and whether improvement in cardiac function is related to cardiac differentiation of ESCs. All animal procedures were approved by the institutional animal care and use committee. Murine ESCs were stably transfected with a mutant version of herpes simplex virus type 1 thymidine kinase, HSV1-sr39tk, and also were labeled with superparamagnetic iron oxide (SPIO) particles. Cells were injected directly in the border zone of the infarcted heart or in corresponding regions of normal hearts in athymic rats. PET and MR imaging were performed longitudinally for 4 weeks in the same animals. ESCs survived and underwent proliferation in the infarcted and normal hearts, as demonstrated by serial increases in 9-(4-[(18)F]fluoro-3-hydroxymethylbutyl) guanine PET signals. In parallel, the hypointense areas on MR images at the injection sites decreased over time. Double staining for host macrophages and SPIO particles revealed that the majority of SPIO-containing cells were macrophages at week 4 after injection. Left ventricular ejection fraction increased in the ESC-treated rats but decreased in culture media-treated rats, and border-zone function was preserved in ESC-treated animals; however, cardiac differentiation of ESCs was less than 0.5%. Dual-modality imaging permits complementary information in regard to cell survival and proliferation, graft formation, and effects on cardiac function. http://radiology.rsnajnls.org/cgi/content/full/250/3/821/DC1. RSNA, 2009

XPS and NRA investigations during the fabrication of gold nanostructured functionalized screen-printed sensors for the detection of metallic pollutants

NASA Astrophysics Data System (ADS)

Jasmin, Jean-Philippe; Miserque, Frédéric; Dumas, Eddy; Vickridge, Ian; Ganem, Jean-Jacques; Cannizzo, Caroline; Chaussé, Annie

2017-03-01

An all covalent nanostructured lead sensor was built by the successive grafting of gold nanoparticles and carboxylic ligands at the surface of self-adhesive carbon screen-printed electrodes (SPEs). Surface analysis techniques were used in each step in order to investigate the structuration of this sensor. The self-adhesive surfaces were made from the electrochemical grafting of p-phenylenediamine at the surface of the SPEs via diazonium salts chemistry. The quantity of grafted aniline functions, estimated by Nuclear Reaction Analysis (NRA) performed with p-phenylenediamine labelled with 15N isotope, is in agreement with an almost complete coverage of the electrode surface. The subsequent diazotization of the aniline functions at the surface of the SPEs was performed; X-ray Photoelectron Spectroscopy (XPS) allowed us to consider a quantitative conversion of the aniline functions into diazonium moieties. The spontaneous grafting of gold nanoparticles on the as-obtained reactive surfaces ensures the nanostructuration of the material, and XPS studies showed that the covalent bonding of the gold nanoparticles at the surface of the SPEs induces a change both in the Au-4f (gold nanoparticles) and Cl-2p (carbon ink) core level signals. These unusual observations are explained by an interaction between the carbon ink constituting the substrate and the gold nanoparticles. Heavy and toxic metals are considered of major environmental concern because of their non-biodegradability. In a final step, the grafting of the carboxylic ligands at the surface of the SPEs and an accumulation step in the presence of lead(II) cations allowed us to evidence the interest of nanostructured materials as metallic pollutants sensors.

The incidence, risk factors, and outcomes of primary poor graft function after unmanipulated haploidentical stem cell transplantation.

PubMed

Sun, Yu-Qian; He, Gan-Lin; Chang, Ying-Jun; Xu, Lan-Ping; Zhang, Xiao-Hui; Han, Wei; Chen, Huan; Chen, Yu-Hong; Wang, Yu; Wang, Feng-Rong; Wang, Jing-Zhi; Liu, Kai-Yan; Huang, Xiao-Jun

2015-10-01

Primary poor graft function (PGF) is a severe complication after allogeneic stem cell transplantation (SCT). The incidence, risk factors, and outcomes of PGF have not been well described, especially in the haploidentical SCT setting. We retrospectively reviewed patients who received haploidentical SCT at Peking University Institute of Hematology between January 1, 2011, and December 31, 2012. PGF was defined as persistent neutropenia (≤0.5 × 10(9) L(-1)), thrombocytopenia (platelets ≤20 × 10(9) L(-1)), and/or hemoglobin ≤70 g L(-1) after engraftment with hypocellular bone marrow and full donor chimerism, without concurrent graft-versus-host disease or disease relapse. Incidence was calculated from all patients. Of the 464 total patients, 26 (5.6 %) developed primary PGF. The risk factors were analyzed and compared with control patients with good graft function who were selected using the case-pair method. Finally, 104 patients were selected as a control group according to the matching conditions: (1) the type (acute leukemia, myelodysplastic syndrome (MDS), chronic myelogenous leukemia (CML)) and status (standard risk, high risk) of underlying disease, (2) sex, (3) year in which the transplantation was received, and (4) a 1:4 ratio of case-control. No factors were found to be associated with primary PGF. Compared to cases with good graft function, patients with primary PGF experienced poor overall survival (34.6 vs. 82.7 %, p < 0.001). Of the 26 primary PGF patients, only nine achieved hematopoietic recovery and survived. In conclusion, primary PGF is a rare but life-threatening complication after haploidentical SCT, and effective therapies need to be explored.

Predicting the ideal serum creatinine of kidney transplant recipients by a simple formula based on the balance between metabolic demands of recipients and renal mass supply from donors.

PubMed

Oh, C K; Lee, B M; Kim, H; Kim, S I; Kim, Y S

2008-09-01

Serum creatinine (Scr) is the most frequently used test to estimate graft function after kidney transplantation. Our previous study demonstrated that the independent predictors of recipient posttransplantation Scr included the ratio of graft weight to recipient body weight, the ratio of graft weight to recipient body surface area (BSA), and the ratio of graft weight to recipient body mass index (BMI). A prospective analysis about the impact of the balance between metabolic demands and renal supply on posttransplantation Scr of recipients was previously reported. We plotted the scatter graph using the X-axis as the independent predictors of Scr by linear regression and the Y-axis as the recipient Scr. To generate the predictive formula of Scr, we calculated a fit of the line of plotted cases using a linear regression method with 2 regression lines for prediction of the upper and lower 95% confidence intervals. Each line was converted into a predictive formula: Scr = -0.0033* (Graft weight(g)/Recipient BSA(m2))+1.75. Under 95% confidence, the Scr ranges from -0.0033* (Graft weight(g)/Recipient BSA(m2))+1.07 to -0.0033* (Graft weight(g)/Recipient BSA (m2))+2.44. Scr = -0.1049* (Graft weight(g)/Recipient body weight(kg))+1.72, which ranges from -0.1049* (Graft weight(g)/Recipient body weight(kg))+1.06 to -0.1049* (Graft weight(g)/Recipient body weight(kg))+2.37. Scr = -0.0158* (Graft weight(g)/Recipient BMI(kg/m2))+1.56, which ranges from -0.0158* (Graft weight(g)/Recipient BMI(kg/m2))+0.75 to -0.0158* (Graft weight(g)/Recipient BMI(kg/m2))+2.26. Prediction of posttransplantation Scr may be achieved by measuring graft weight as well as recipient weight and height. When recipient Scr is significantly higher than that predicted by the formula, a clinician should suspect an underlying graft injury.

Inter-Species Grafting Caused Extensive and Heritable Alterations of DNA Methylation in Solanaceae Plants

PubMed Central

Lin, Yan; Ma, Yiqiao; Liu, Gang; Yu, Xiaoming; Zhong, Silin; Liu, Bao

2013-01-01

Background Grafting has been extensively used to enhance the performance of horticultural crops. Since Charles Darwin coined the term “graft hybrid” meaning that asexual combination of different plant species may generate products that are genetically distinct, highly discrepant opinions exist supporting or against the concept. Recent studies have documented that grafting enables exchanges of both RNA and DNA molecules between the grafting partners, thus providing a molecular basis for grafting-induced genetic variation. DNA methylation is known as prone to alterations as a result of perturbation of internal and external conditions. Given characteristics of grafting, it is interesting to test whether the process may cause an alteration of this epigenetic marker in the grafted organismal products. Methodology/Principal Findings We analyzed relative global DNA methylation levels and locus-specific methylation patterns by the MSAP marker and locus-specific bisulfite-sequencing in the seed plants (wild-type controls), self- and hetero-grafted scions/rootstocks, selfed progenies of scions and their seed-plant controls, involving three Solanaceae species. We quantified expression of putative genes involved in establishing and/or maintaining DNA methylation by q-(RT)-PCR. We found that (1) hetero-grafting caused extensive alteration of DNA methylation patterns in a locus-specific manner, especially in scions, although relative methylation levels remain largely unaltered; (2) the altered methylation patterns in the hetero-grafting-derived scions could be inherited to sexual progenies with some sites showing further alterations or revisions; (3) hetero-grafting caused dynamic changes in steady-state transcript abundance of genes encoding for a set of enzymes functionally relevant to DNA methylation. Conclusions/Significance Our results demonstrate that inter-species grafting in plants could produce extensive and heritable alterations in DNA methylation. We suggest that these readily altered, yet heritable, epigenetic modifications due to interspecies hetero-grafting may shed one facet of insight into the molecular underpinnings for the still contentious concept of graft hybrid. PMID:23614002

Thrombin immobilization to methacrylic acid grafted poly(3-hydroxybutyrate) and its in vitro application.

PubMed

Akkaya, Alper; Pazarlioglu, Nurdan

2013-01-01

Poly(3-hydroxybutyrate) is nontoxic and biodegradable, with good biocompatibility and potential support for long-term implants. For this reason, it is a good support for enzyme immobilization. Enzyme immobilization could not be done directly because poly(3-hydroxybutyrate) has no functional groups. Therefore, modification should be done for enzyme immobilization. In this study, methacrylic acid was graft polymerized to poly(3-hydroxybutyrate) and thrombin was immobilized to polymethacrylic acid grafted poly(3-hydroxybutyrate). In fact, graft polymerization of methacrylic acid to poly(3-hydroxybutyrate) and thrombin immobilization was a model study. Biomolecule immobilized poly(3-hydroxybutyrate) could be used as an implant. Thrombin was selected as a biomolecule for this model study and it was immobilized to methacrylic acid grafted poly(3-hydroxybutyrate). Then the developed product was used to stop bleeding.

Effectiveness of Acellular Dermal Matrix on Autologous Split-Thickness Skin Graft in Treatment of Deep Tissue Defect: Esthetic Subjective and Objective Evaluation.

PubMed

Lee, Yoo Jung; Park, Myong Chul; Park, Dong Ha; Hahn, Hyung Min; Kim, Sue Min; Lee, Il Jae

2017-10-01

A split-thickness skin graft (STSG) is performed to cover a large full-thickness skin defect. Esthetic and functional deficits can result, and many studies have sought to overcome them. This study compared the effectiveness of the acellular dermal matrix (ADM) graft and STSG concerning esthetic and functional effectiveness of ADM on scar quality. Of the patients who underwent anterolateral thigh free flap from 2011 to 2015, patients who received skin graft only (n = 10) or skin graft with ADM (n = 20) for coverage of the donor site were enrolled. In all cases, autologous STSG was performed with 1:1.5 meshed 0.008-0.010-inch-thick skin. In the skin graft with ADM group, 0.008-0.013-inch-thick meshed ADM (CGderm ® ; CGBio, Inc., Seungnam, Korea) was co-grafted. Negative-pressure wound therapy (CuraVAC ® ; CGBio, Inc., Seungnam, Korea) was applied to both groups in continuous mode at -120 mmHg. We investigate early outcomes (skin loss rate, duration of negative-pressure wound therapy, days to removal of stitches, days to achieve complete healing, and complications) and late outcomes in terms of scar quality (vascularity, pigmentation, pliability and height) and graft-related symptoms (itching sensation and pain). Assessments used the Vancouver Scar Scale and the Patient and Observer Scar Assessment Scale. Skin fold was measured to evaluate the elasticity of scar tissue. In the Vancouver Scar Scale, vascularity subscore (p = 0.003) and total score (p = 0.016) were significantly lower in the skin graft with ADM group. In Patient and Observer Scar Assessment Scale, the pain (p = 0.037) and stiffness subscores (p = 0.002), and total score (p = 0.017) were significantly lower in the skin graft with ADM group. Skin graft with ADM results in better scar quality in objective and subjective aspects. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Hamstring tendon versus patellar tendon anterior cruciate ligament reconstruction using biodegradable interference fit fixation: a prospective matched-group analysis.

PubMed

Wagner, Michael; Kääb, Max J; Schallock, Jessica; Haas, Norbert P; Weiler, Andreas

2005-09-01

There are still controversies about graft selection for primary anterior cruciate ligament reconstruction, especially with respect to knee stability and functional outcome. Biodegradable interference screw fixation of hamstring tendon grafts provides clinical results similar to those achieved with identical fixation of bone-patellar tendon-bone grafts. Cohort study; Level of evidence, 2. In 1996 and 1997, primary isolated anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft was performed in 72 patients. Since 1998, hamstring tendons were used as routine grafts. Matched patients with a hamstring tendon graft were selected from a database (n = 284). All patients were followed prospectively for a minimum of 2 years with KT-1000 arthrometer testing, International Knee Documentation Committee score, and Lysholm score. In the bone-patellar tendon-bone group, 9 patients were excluded because of bilateral rupture of the anterior cruciate ligament, 3 patients (4.2%) had a graft rupture, and 4 patients were lost to follow-up (follow-up rate, 92.1%), leaving 56 patients for a matched-group analysis. In the hamstring tendon database, the graft rupture rate was 5.6% (P = .698). The Lysholm score was 89.7 in the patellar tendon group and 94 in the hamstring tendon group (P = .003). The KT-1000 arthrometer side-to-side difference was 2.6 mm for the patellar tendon group and 2.1 mm for the hamstring tendon group (P = .041). There were significantly less positive pivot-shift test results in the hamstring tendon group (P = .005), and hamstring tendon patients showed lower thigh atrophy (P = .024) and patellofemoral crepitus (P = .003). Overall International Knee Documentation Committee scores were better (P = .001) in the hamstring tendon group (hamstring tendon: 34 x A, 21 x B, 0 x C, 0 x D; bone-patellar tendon-bone: 17 x A, 32 x B, 6 x C, 0 x D). In this comparison of anterior cruciate ligament reconstruction with bone-patellar tendon-bone and anatomical hamstring tendon grafts, the hamstring tendon graft was superior in knee stability and function. These findings are partially contrary to previous studies and might be attributable to the use of an anatomical joint line fixation for hamstring tendon grafts. Thus, hamstring tendons are the authors' primary graft choice for anterior cruciate ligament reconstruction, even in high-level athletes.

[Paired kidneys in transplant].

PubMed

Regueiro López, Juan C; Leva Vallejo, Manuel; Prieto Castro, Rafael; Anglada Curado, Francisco; Vela Jiménez, Francisco; Ruiz García, Jesús

2009-02-01

Many factors affect the graft and patient survival on the renal transplant outcome. These factors depend so much of the recipient and donor. We accomplished a study trying to circumvent factors that depend on the donor. We checked the paired kidneys originating of a same donor cadaver. We examined the risk factors in the evolution and follow-up in 278 couples of kidney transplant. We describe their differences, significance, the graft and patient survival, their functionality in 3 and 5 years and the risk factors implicated in their function. We study immunogenic and no immunogenic variables, trying to explain the inferior results in the grafts that are established secondly. We regroup the paired kidneys in those that they did not show paired initial function within the same couple. The results yield a discreet deterioration in the graft and patient survival for second group establish, superior creatinina concentration, without obtaining statistical significance. The Cox regression study establishes the early rejection (inferior to three months) and DR incompatibility values like risk factors. This model of paired kidneys would be able to get close to best-suited form for risk factors analysis in kidney transplant from cadaver donors, if more patients examine themselves in the same way. The paired kidneys originating from the same donor do not show the same function in spite of sharing the same conditions of the donor and perioperative management.

Uncultured undifferentiated adipose-derived nucleated cell fractions combined with inside-out artery graft accelerate sciatic nerve regeneration and functional recovery.

PubMed

Mohammadi, R; Asadollahi, A; Amini, K

2014-09-01

Effects of transplantation of adipose-derived nucleated cell fractions (ADNCs) on sciatic nerve regeneration were studied. A 10-mm sciatic nerve defect was bridged using artery graft filled with ADNCs. In control group, artery graft was filled with saline alone. Regenerated nerve fibres were studied for 12 weeks. In sham-operated group, sciatic nerve was only exposed and manipulated. Behavioural and functional studies confirmed faster recovery of regenerated axons in ADNCs transplanted animals than in control group (P<0.05). At the end of study period, animals in ADNCs transplanted group achieved a sciatic functional index (SFI) value of -31.6 ± -3.14, whereas in control group a value of -42.5 ± -3.7 was found. Gastrocnemius muscle mass in ADNCs transplanted animals was found to be significantly higher than that in control group (P=0.001). Morphometric indices of regenerated fibres showed the number and diameter of myelinated fibres to be significantly higher in ADNCs transplanted animals than in control group (P=0.001). On immunohistochemistry, there was more positive staining of S100 in the ADNCs transplanted animals than in control group. ADNCs transplantation into an artery graft could be considered a readily accessible technique that improves functional recovery of sciatic nerve. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Tissue-engineered matrices as functional delivery systems: adsorption and release of bioactive proteins from degradable composite scaffolds.

PubMed

Cushnie, Emily K; Khan, Yusuf M; Laurencin, Cato T

2010-08-01

A tissue-engineered bone graft should imitate the ideal autograft in both form and function. However, biomaterials that have appropriate chemical and mechanical properties for grafting applications often lack biological components that may enhance regeneration. The concept of adding proteins such as growth factors to scaffolds has therefore emerged as a possible solution to improve overall graft design. In this study, we investigated this concept by loading porous hydroxyapatite-poly(lactide-co-glycolide) (HA-PLAGA) scaffolds with a model protein, cytochrome c, and then studying its release in a phosphate-buffered saline solution. The HA-PLAGA scaffold has previously been shown to be bioactive, osteoconductive, and to have appropriate physical properties for tissue engineering applications. The loading experiments demonstrated that the HA-PLAGA scaffold could also function effectively as a substrate for protein adsorption and release. Scaffold protein adsorptive loading (as opposed to physical entrapment within the matrix) was directly related to levels of scaffold HA-content. The HA phase of the scaffold facilitated protein retention in the matrix following incubation in aqueous buffer for periods up to 8 weeks. Greater levels of protein retention time may improve the protein's effective activity by increasing the probability for protein-cell interactions. The ability to control protein loading and delivery simply via composition of the HA-PLAGA scaffold offers the potential of forming robust functionalized bone grafts. (c) 2010 Wiley Periodicals, Inc.

EndoAnchors to Resolve Persistent Type Ia Endoleak Secondary to Proximal Cuff With Parallel Graft Placement.

PubMed

Donselaar, Esmé J; van der Vijver-Coppen, Rozemarijn J; van den Ham, Leo H; Lardenoye, Jan Willem H P; Reijnen, Michel M P J

2016-02-01

To describe 2 patients with a distally migrated endograft causing a type Ia endoleak and treatment with a proximal cuff and chimney grafts that required EndoAnchors to finally seal the leak. Two men, ages 86 and 72 years, presented with stent-graft migration and type Ia endoleak at 5 and 15 years after endovascular repair, respectively. Both were treated with a proximal cuff in combination with a chimney graft to the left renal artery. In both cases, the type Ia endoleak persisted, likely due to gutter formation. Both patients were treated in the same setting with EndoAnchors that instantly resolved the endoleak. At 1-year follow-up, there was no recurrent endoleak or migration, with patent chimney grafts and renal arteries and stable renal function. EndoAnchors may effectively resolve a persistent type Ia endoleak arising from gutter formation after placement of a proximal cuff and chimney grafts. © The Author(s) 2015.

Osteoconductive composite graft based on bacterial synthesized hydroxyapatite nanoparticles doped with different ions: From synthesis to in vivo studies.

PubMed

Ahmadzadeh, Elham; Talebnia, Farid; Tabatabaei, Meisam; Ahmadzadeh, Hossein; Mostaghaci, Babak

2016-07-01

To repair damaged bone tissues, osteoconductive bone graft substitutes are required for enhancement of the regenerative potential of osteoblast cells. Nanostructured hydroxyapatite is a bioactive ceramic used for bone tissue engineering purposes. In this study, carbonate hydroxyapatite (cHA) and zinc-magnesium substituted hydroxyapatite (Zn-Mg-HA) nanoparticles were synthesized via biomineralization method using Enterobacter aerogenes. The structural phase composition and the morphology of the samples were analyzed using appropriate powder characterization methods. Next, a composite graft was fabricated by using polyvinyl alcohol and both cHA and Zn-Mg-HA samples. In vivo osteogenic potential of the graft was then investigated in a rabbit tibial osteotomy model. Histological, radiological and morphological studies showed that the graft was mineralized by the newly formed bone tissue without signs of inflammation or infection after 4 weeks of implantation. These histomorphometric results suggest that the fabricated graft can function as a potent osteoconductive bone tissue substitute. Copyright © 2016 Elsevier Inc. All rights reserved.

Cellulose microfibrils grafted with PBA via surface-initiated atom transfer radical polymerization for biocomposite reinforcement.

PubMed

Li, Shuzhao; Xiao, Miaomiao; Zheng, Anna; Xiao, Huining

2011-09-12

Immobilizing poly(butyl acrylate) (PBA) on cellulose microfibrils (CMFs) by atom transfer radical polymerization (ATRP) of butyl acrylate (BA) on the surface of 2-bromoisobutyryl-functionalized CMF generated highly hydrophobic microfibrils (CMF-PBA) with a hard core and a soft-shell structure. TGA and static water contact angle results suggested that the surfaces of the modified CMF samples were not completely covered by PBA chains until the molecular weight of grafts became sufficiently long. The GPC results indicated that the grafts with low molecular weight showed controlled/"living" characteristics of the surface-initiated ATRP; however, there existed more side reactions with the increase in molecular weights. Biocomposites consisting of polypropylene (PP) and CMF-PBA samples exhibited significantly improved compatibility, interface adhesion, and mechanical properties with the increase in PBA graft length. The findings confirmed that the longer grafts facilitated the better entanglement of PBA grafts with PP macromolecules and thus further improved the mechanical properties.

Engineering live cell surfaces with functional polymers via cytocompatible controlled radical polymerization

NASA Astrophysics Data System (ADS)

Niu, Jia; Lunn, David J.; Pusuluri, Anusha; Yoo, Justin I.; O'Malley, Michelle A.; Mitragotri, Samir; Soh, H. Tom; Hawker, Craig J.

2017-06-01

The capability to graft synthetic polymers onto the surfaces of live cells offers the potential to manipulate and control their phenotype and underlying cellular processes. Conventional grafting-to strategies for conjugating preformed polymers to cell surfaces are limited by low polymer grafting efficiency. Here we report an alternative grafting-from strategy for directly engineering the surfaces of live yeast and mammalian cells through cell surface-initiated controlled radical polymerization. By developing cytocompatible PET-RAFT (photoinduced electron transfer-reversible addition-fragmentation chain-transfer polymerization), synthetic polymers with narrow polydispersity (Mw/Mn < 1.3) could be obtained at room temperature in 5 minutes. This polymerization strategy enables chain growth to be initiated directly from chain-transfer agents anchored on the surface of live cells using either covalent attachment or non-covalent insertion, while maintaining high cell viability. Compared with conventional grafting-to approaches, these methods significantly improve the efficiency of grafting polymer chains and enable the active manipulation of cellular phenotypes.

Grafting of Conductive Polymers onto the Functionalized Carbon Nanotubes

DTIC Science & Technology

2010-08-23

2,5- benzimidazole )/carbon nanotube composite film” Journal of Polymer Science, Part A: Polymer Chemistry 2010, 48, 1067. 3. Han, S.-W.; Oh, S.-J...34Synthesis and Characterization of poly(2,5- benzimidazole ) (ABPBI) Grafted CArbon Nanotubes." MRS. 2009 fall meeting, Prepr. Boston, MA, November 30

The UK DCD Risk Score: A new proposal to define futility in donation-after-circulatory-death liver transplantation.

PubMed

Schlegel, Andrea; Kalisvaart, Marit; Scalera, Irene; Laing, Richard W; Mergental, Hynek; Mirza, Darius F; Perera, Thamara; Isaac, John; Dutkowski, Philipp; Muiesan, Paolo

2018-03-01

Primary non-function and ischaemic cholangiopathy are the most feared complications following donation-after-circulatory-death (DCD) liver transplantation. The aim of this study was to design a new score on risk assessment in liver-transplantation DCD based on donor-and-recipient parameters. Using the UK national DCD database, a risk analysis was performed in adult recipients of DCD liver grafts in the UK between 2000 and 2015 (n = 1,153). A new risk score was calculated (UK DCD Risk Score) on the basis of a regression analysis. This is validated using the United Network for Organ Sharing database (n = 1,617) and our own DCD liver-transplant database (n = 315). Finally, the new score was compared with two other available prediction systems: the DCD risk scores from the University of California, Los Angeles and King's College Hospital, London. The following seven strongest predictors of DCD graft survival were identified: functional donor warm ischaemia, cold ischaemia, recipient model for end-stage liver disease, recipient age, donor age, previous orthotopic liver transplantation, and donor body mass index. A combination of these risk factors (UK DCD risk model) stratified the best recipients in terms of graft survival in the entire UK DCD database, as well as in the United Network for Organ Sharing and in our own DCD population. Importantly, the UK DCD Risk Score significantly predicted graft loss caused by primary non-function or ischaemic cholangiopathy in the futile group (>10 score points). The new prediction model demonstrated a better C statistic of 0.79 compared to the two other available systems (0.71 and 0.64, respectively). The UK DCD Risk Score is a reliable tool to detect high-risk and futile combinations of donor-and-recipient factors in DCD liver transplantation. It is simple to use and offers a great potential for making better decisions on which DCD graft should be rejected or may benefit from functional assessment and further optimization by machine perfusion. In this study, we provide a new prediction model for graft loss in donation-after-circulatory-death (DCD) liver transplantation. Based on UK national data, the new UK DCD Risk Score involves the following seven clinically relevant risk factors: donor age, donor body mass index, functional donor warm ischaemia, cold storage, recipient age, recipient laboratory model for end-stage liver disease, and retransplantation. Three risk classes were defined: low risk (0-5 points), high risk (6-10 points), and futile (>10 points). This new model stratified best in terms of graft survival compared to other available models. Futile combinations (>10 points) achieved an only very limited 1- and 5-year graft survival of 37% and less than 20%, respectively. In contrast, an excellent graft survival has been shown in low-risk combinations (≤5 points). The new model is easy to calculate at the time of liver acceptance. It may help to decide which risk combination will benefit from additional graft treatment, or which DCD liver should be declined for a certain recipient. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Impact of donor hematopoietic cells mobilized with G-CSF and plerixafor on murine acute graft-versus-host-disease.

PubMed

Arbez, Jessy; Saas, Philippe; Lamarthée, Baptiste; Malard, Florent; Couturier, Mélanie; Mohty, Mohamad; Gaugler, Béatrice

2015-07-01

This study aimed to characterize the immune effectors contained in the grafts from donor mice mobilized by granulocyte colony-stimulating factor (G-CSF) and plerixafor and to evaluate their impact on the development of acute graft-versus-host-disease (aGVHD). Mobilization was done with G-CSF alone or G-CSF plus plerixafor (G+P). In grafts collected after G+P mobilization, we observed a significantly higher proportion of c-kit(+)Sca-1(+) hematopoietic stem cells compared with G-CSF. A significant increase in the percentage of plasmacytoid dendritic cells was detected in the G+P graft compared with G-CSF graft. We also studied the ability of stem cell grafts mobilized with G+P to induce GVHD in a mouse model. We observed higher mortality (P < 0.001) associated with increased aGVHD clinical score (P < 0.0001) as well as higher pathology score in the intestine of mice receiving G+P as compared with G-CSF grafts (P < 0.001). Moreover, the exacerbated aGVHD severity was associated with upregulation of CCR6 expression on both CD4(+) and CD8(+) T cells from the G+P grafts, as well as on T cells from mice transplanted with G+P grafts. In conclusion, we showed that grafts mobilized with G+P exhibited functional features different from those mobilized with G-CSF alone, which increase the severity of aGVHD in the recipients. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Dual kidneys from marginal adult donors as a source for cadaveric renal transplantation in the United States.

PubMed

Bunnapradist, Suphamai; Gritsch, H Albin; Peng, Alice; Jordan, Stanley C; Cho, Yong W

2003-04-01

The current organ shortage has led to the utilization of double kidney transplants from marginal adult donors, but outcomes data are limited. The United Network for Organ Sharing registry database was used to compare the outcomes of 403 dual adult kidney transplantations (DKT) and 11,033 single kidney transplantations (SKT) from 1997 to 2000. Graft and patient survival and the effect of multiple risk factors were evaluated. It was found that DKT patients were older, less sensitized, and received grafts from older, more mismatched donors with longer cold ischemia times. There was also a greater percentage of donors with a history of diabetes or hypertension and African-American recipients and donors in the DKT group. Graft survival was inferior in the DKT group, with a 7% lower graft survival rate at 1 yr. There was a higher incidence of primary nonfunction in the DKT group, although the incidence of delayed graft function, early rejection treatment, and graft thrombosis did not differ. Multivariate analysis was used to identify African-American recipient ethnicity and retransplant as risk factors for graft loss. Graft survival was comparable in DKT and SKT with donors over 55 yr of age. DKT resulted in inferior graft outcomes compared with SKT. When compared with SKT with donors over 55 yr of age, DKT resulted in similar graft outcomes. These otherwise discarded kidneys should be cautiously considered as a source of marginal donors.

Penile Reconstruction with Skin Grafts and Dermal Matrices: Indications and Management

PubMed Central

Triana Junco, Paloma; Dore, Mariela; Nuñez Cerezo, Vanesa; Jimenez Gomez, Javier; Miguel Ferrero, Miriam; Díaz González, Mercedes; Lopez-Pereira, Pedro; Lopez-Gutierrez, Juan Carlos

2017-01-01

Introduction  The penis eventually needs specific cutaneous coverage in the context of reconstructive procedures following trauma or congenital anomalies. Local flaps are the first choice but are not always available after multiple previous procedures. In these cases, skin graft and dermal matrices should be considered. Materials and Methods  This study was a retrospective review of the past 4 years of four patients with severe loss of penile shaft skin who underwent skin reconstruction. Dermal matrices and skin grafts were utilized. Dermal matrices were placed for a median of 4.5 weeks (3.0–6.0 weeks). The skin graft was harvested from the inner thigh region for split-thickness skin graft (STSG) and the inguinal region for full-thickness skin graft (FTSG). Results  The four patients presented with complete loss of skin in the penile shaft. One patient had a vesical exstrophy, one had a buried penis with only one corpus cavernosum, one had a wide congenital lymphedema of the genitalia, and one had a lack of skin following circumcision at home. They underwent reconstruction with three patients undergoing split-thickness skin graft; two dermal matrices; and one full-thickness graft, respectively, thereby achieving a good cosmetic and functional result. There were no complications, and all the patients successfully accepted the graft. Conclusion  Dermal matrices and skin grafts may serve as effective tools in the management of severe penile skin defects unable to be covered with local flaps. PMID:28868232

Donor Hemodynamics as a Predictor of Outcomes After Kidney Transplantation From Donors After Cardiac Death.

PubMed

Allen, M B; Billig, E; Reese, P P; Shults, J; Hasz, R; West, S; Abt, P L

2016-01-01

Donation after cardiac death is an important source of transplantable organs, but evidence suggests donor warm ischemia contributes to inferior outcomes. Attempts to predict recipient outcome using donor hemodynamic measurements have not yielded statistically significant results. We evaluated novel measures of donor hemodynamics as predictors of delayed graft function and graft failure in a cohort of 1050 kidneys from 566 donors. Hemodynamics were described using regression line slopes, areas under the curve, and time beyond thresholds for systolic blood pressure, oxygen saturation, and shock index (heart rate divided by systolic blood pressure). A logistic generalized estimation equation model showed that area under the curve for systolic blood pressure was predictive of delayed graft function (above median: odds ratio 1.42, 95% confidence interval [CI] 1.06-1.90). Multivariable Cox regression demonstrated that slope of oxygen saturation during the first 10 minutes after extubation was associated with graft failure (below median: hazard ratio 1.30, 95% CI 1.03-1.64), with 5-year graft survival of 70.0% (95%CI 64.5%-74.8%) for donors above the median versus 61.4% (95%CI 55.5%-66.7%) for those below the median. Among older donors, increased shock index slope was associated with increased hazard of graft failure. Validation of these findings is necessary to determine the utility of characterizing donor warm ischemia to predict recipient outcome. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

Adapting BODIPYs to singlet oxygen production on silica nanoparticles.

PubMed

Epelde-Elezcano, Nerea; Prieto-Montero, Ruth; Martínez-Martínez, Virginia; Ortiz, María J; Prieto-Castañeda, Alejandro; Peña-Cabrera, Eduardo; Belmonte-Vázquez, José L; López-Arbeloa, Iñigo; Brown, Ross; Lacombe, Sylvie

2017-05-31

A modified Stöber method is used to synthesize spherical core-shell silica nanoparticles (NPs) with an external surface functionalized by amino groups and with an average size around 50 nm. Fluorescent dyes and photosensitizers of singlet oxygen were fixed, either separately or conjointly, respectively in the core or in the shell. Rhodamines were encapsulated in the core with relatively high fluorescence quantum yields (Φ fl ≥ 0.3), allowing fluorescence tracking of the particles. Various photosensitizers of singlet oxygen (PS) were covalenty coupled to the shell, allowing singlet oxygen production. The stability of NP suspensions strongly deteriorated upon grafting the PS, affecting their apparent singlet oxygen quantum yields. Agglomeration of NPs depends both on the type and on the amount of grafted photosensitizer. New, lab-made, halogenated 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPY) grafted to the NPs achieved higher singlet oxygen quantum yields (Φ Δ ∼ 0.35-0.40) than Rose Bengal (RB) grafted NPs (Φ Δ ∼ 0.10-0.27). Finally, we combined both fluorescence and PS functions in the same NP, namely a rhodamine in the silica core and a BODIPY or RB grafted in the shell, achieving the performance Φ fl ∼ 0.10-0.20, Φ Δ ∼ 0.16-0.25 with a single excitation wavelength. Thus, proper choice of the dyes, of their concentrations inside and on the NPs and the grafting method enables fine-tuning of singlet oxygen production and fluorescence emission.

Exogenous BDNF enhances the integration of chronically injured axons that regenerate through a peripheral nerve grafted into a chondroitinase-treated spinal cord injury site

PubMed Central

Tom, Veronica J.; Sandrow-Feinberg, Harra R.; Miller, Kassi; Domitrovich, Cheryl; Bouyer, Julien; Zhukareva, Victoria; Klaw, Michelle C.; Lemay, Michel A.; Houlé, John D.

2016-01-01

Although axons lose some of their intrinsic capacity for growth after their developmental period, some axons retain the potential for regrowth after injury. When provided with a growth-promoting substrate such as a peripheral nerve graft (PNG), severed axons regenerate into and through the graft; however, they stop when they reach the glial scar at the distal graft-host interface that is rich with inhibitory chondroitin sulfate proteoglycans. We previously showed that treatment of a spinal cord injury site with chondroitinase (ChABC) allows axons within the graft to traverse the scar and reinnervate spinal cord, where they form functional synapses. While this improvement in outgrowth was significant, it still represented only a small percentage (<20%) of axons compared to the total number of axons that regenerated into the PNG. Here we tested whether providing exogenous brain-derived neurotrophic factor (BDNF) via lentivirus in tissue distal to the PNG would augment regeneration beyond a ChABC-treated glial interface. We found that ChABC treatment alone promoted axonal regeneration but combining ChABC with BDNF-lentivirus did not increase the number of axons that regenerated back into spinal cord. Combining BDNF with ChABC did increase the number of spinal cord neurons that were trans-synaptically activated during electrical stimulation of the graft, as indicated by c-Fos expression, suggesting that BDNF overexpression improved the functional significance of axons that did reinnervate distal spinal cord tissue. PMID:23022460

Do Alloreactivity and Prolonged Cold Ischemia Cause Different Elementary Lesions in Chronic Allograft Nephropathy?

PubMed Central

Herrero-Fresneda, Immaculada; Torras, Joan; Cruzado, Josep M.; Condom, Enric; Vidal, August; Riera, Marta; Lloberas, Nuria; Alsina, Jeroni; Grinyo, Josep M.

2003-01-01

This study assesses the individual contributions of the nonalloreactive factor, cold ischemia (CI), and alloreactivity to late functional and structural renal graft changes, and examines the effect of the association of both factors on the progression of chronic allograft nephropathy. Lewis rats acted as receptors of kidneys from either Lewis or Fischer rats. For CI, kidneys were preserved for 5 hours. The rats were divided into four groups: Syn, syngeneic graft; SynI, syngeneic graft and CI; Allo, allogeneic graft; AlloI, allogeneic graft and CI. Renal function was assessed every 4 weeks for 24 weeks. Grafts were evaluated for acute inflammatory response at 1 week and for chronic histological damage at 24 weeks. Only when CI and allogenicity were combined did immediate posttransplant mortality occur, while survivors showed accelerated renal insufficiency that induced further mortality at 12 weeks after transplant. Solely ischemic rats developed renal insufficiency. Renal structural damage in ischemic rats was clearly tubulointerstitial, while significant vasculopathy and glomerulosclerosis appeared only in the allogeneic groups. There was increased infiltration of macrophages and expression of mRNA-transforming growth factor-β1 in the ischemic groups, irrespective of the allogeneic background. The joint association of CI plus allogenicity significantly increased cellular infiltration at both early and late stages, aggravating tubulointerstitial and vascular damage considerably. In summary, CI is mainly responsible for tubulointerstitial damage, whereas allogenicity leads to vascular lesion. The association of both factors accelerates and aggravates the progression of experimental chronic allograft nephropathy. PMID:12507896

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.

Engineering the mechanical and biological properties of nanofibrous vascular grafts for in situ vascular tissue engineering.

PubMed

Henry, Jeffrey J D; Yu, Jian; Wang, Aijun; Lee, Randall; Fang, Jun; Li, Song

2017-08-17

Synthetic small diameter vascular grafts have a high failure rate, and endothelialization is critical for preventing thrombosis and graft occlusion. A promising approach is in situ tissue engineering, whereby an acellular scaffold is implanted and provides stimulatory cues to guide the in situ remodeling into a functional blood vessel. An ideal scaffold should have sufficient binding sites for biomolecule immobilization and a mechanical property similar to native tissue. Here we developed a novel method to blend low molecular weight (LMW) elastic polymer during electrospinning process to increase conjugation sites and to improve the mechanical property of vascular grafts. LMW elastic polymer improved the elasticity of the scaffolds, and significantly increased the amount of heparin conjugated to the micro/nanofibrous scaffolds, which in turn increased the loading capacity of vascular endothelial growth factor (VEGF) and prolonged the release of VEGF. Vascular grafts were implanted into the carotid artery of rats to evaluate the in vivo performance. VEGF treatment significantly enhanced endothelium formation and the overall patency of vascular grafts. Heparin coating also increased cell infiltration into the electrospun grafts, thus increasing the production of collagen and elastin within the graft wall. This work demonstrates that LMW elastic polymer blending is an approach to engineer the mechanical and biological property of micro/nanofibrous vascular grafts for in situ vascular tissue engineering.

Acetabular fractures in the elderly treated with a primary Burch-Schneider reinforcement ring, autologous bone graft, and a total hip arthroplasty: a prospective study with a 4-year follow-up.

PubMed

Enocson, Anders; Blomfeldt, Richard

2014-06-01

To investigate the clinical and radiologic outcomes in elderly patients suffering from an acetabular fracture operated with an acute primary acetabular reinforcement ring, autologous bone graft, and a total hip arthroplasty (THA). Prospective cohort study. Tertiary care university hospital. Fifteen elderly patients (7 women) with a mean age of 76 years and a displaced acetabular fracture after a low-energy trauma were included. The fractures involved the anterior column, but no patients with associated both column fractures were included. All the patients were able to walk independently before the fracture occurred. Primary operation with a Burch-Schneider reinforcement ring, autologous bone graft, and a THA. The patients were reviewed at 4, 12, 24, and 48 months after the fracture occurred. The outcome assessments included complications, reoperations, activity of daily living function, functional scores (Harris hip score and short musculoskeletal function assessment), health-related quality of life [EuroQol (EQ-5D) index score], and radiologic evaluation. There were no prosthetic dislocations, periprosthetic fractures, deep infections, or other adverse events. There were no radiologic signs of loosening of the reinforcement ring or the prosthesis components at any of the follow up sessions, and the autologous bone graft was well incorporated in all the patients at the final follow-up. At 48 months, the mean Harris hip score was 88, the mean short musculoskeletal function assessment dysfunction score was 30, the bother score was 25, and the mean EQ-5D index score was 0.65. All the patients were able to walk independently at the final follow-up. Treatment of displaced anterior column, anterior column posterior hemitransverse and transverse acetabular fractures in elderly patients using a primary reinforcement ring, autologous bone graft, and a THA seems to be a safe option with good functional and radiologic outcomes. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Mineralocorticoid receptor antagonists in kidney transplantation: time to consider?

PubMed

Girerd, Sophie; Jaisser, Frédéric

2018-04-17

Although patient survival is significantly improved by kidney transplantation (KT) in comparison with dialysis, it remains significantly lower than that observed in the general population. Graft function is one of the major determinants of patient survival after KT. Mineralocorticoid receptor antagonists (MRAs) could be of particular interest in this population to improve graft function and treat or prevent cardiovascular (CV) complications. In KT, ischaemia/reperfusion injury is a major factor involved in delayed graft function, which is often associated with inferior long-term graft survival. Preclinical studies suggest that MRAs may prevent ischaemia/reperfusion-related lesions in addition to having a protective effect in preventing calcineurin inhibitor-induced nephrotoxicity. Clinical data also support the anti-proteinuric effect of MRAs in chronic kidney disease (CKD). Taken together, MRAs may hence be of particular benefit in improving short- and long-term graft function. Numerous randomized controlled trials (RCTs) have shown the efficacy of MRAs in both heart failure and resistant hypertension. As these comorbidities are frequent in kidney transplant recipients before transplantation or during follow-up, MRAs could represent a useful therapeutic option in those with mild renal function impairment. However, CKD patients are under-represented in RCTs and the CV effects of MRAs in kidney transplant recipients have yet to be specifically assessed in large-scale trials. Available evidence indicates a good safety profile for MRAs in patients with a glomerular filtration rate (GFR) >30 mL/min/1.73 m2. However, as for all patients prescribed an MRA, creatinine and potassium should also be closely monitored following MRA initiation in kidney transplant patients. Given the current evidence suggesting that MRAs prevent ischaemia/reperfusion-related lesions and calcineurin inhibitor-induced nephrotoxicity in kidney transplant recipients as well as CV events in patients at high risk of CV complications (such as those in kidney transplant recipients), trials are urgently needed to fully assess the clinical impact of MRA use in this population.

Evaluation of pre-implantation kidney biopsies: comparison of Banff criteria to a morphometric approach.

PubMed

Lopes, José António; Moreso, Francesc; Riera, Luis; Carrera, Marta; Ibernon, Meritxell; Fulladosa, Xavier; Grinyó, Josep Maria; Serón, Daniel

2005-04-01

Donor glomerulosclerosis, interstitial fibrosis, and fibrous intimal thickening correlate with graft outcome. We evaluate chronic lesions in donor biopsies according to Banff criteria and with a morphometric technique to ascertain their predictive value on graft outcome. We evaluated 77 cadaveric donor biopsies according to Banff criteria. Glomerulosclerosis was expressed as the percentage of global sclerotic glomeruli. The following morphometric parameters were obtained: cortical interstitial volume fraction (Vvint/c), cortical glomerular volume fraction (Vvglom/c), mean glomerular volume (Vg), mean and maximal intimal arterial volume fraction (Vvintima/art), and Vvintima/art of the largest artery. We evaluated the correlation of histologic lesions with delayed graft function, 3 months' glomerular filtration rate (GFR), and death-censored graft survival. Multivariate logistic regression showed that delayed graft function was associated with cv score [relative risk (RR) 4.2 and 95% CI 1.1 to 16.0) and glomerulosclerosis (RR 1.06 and 95% CI 1.01 to 1.13). Stepwise regression showed that Vvint/c and glomerulosclerosis were independent predictors of 3 months' GFR (R= 0.62, P= 0.0001). Repeated analysis not considering morphometric parameters showed that glomerulosclerosis, cv score and ci score were independent predictors of 3 months' GFR (R= 0.64, P= 0.0001). A donor chronic damage score was generated considering glomerulosclerosis, cv score and ci score. This score after adjusting for clinical variables was associated with 3 months' GFR (R= 0.71, P < 0.0001) and death-censored graft survival (RR 2.2 and 95% CI 1.3 to 3.7). Combined evaluation of donor glomerulosclerosis, chronic vascular and interstitial damage according to Banff criteria allows a precise prediction of graft outcome. Morphometric evaluation of donor biopsies does not improve the predictive value of semiquantitative grading.

Resistive index and chronic allograft nephropathy evaluated in protocol biopsies as predictors of graft outcome.

PubMed

Vallejos, Augusto; Alperovich, Gabriela; Moreso, Francesc; Cañas, Concepcion; de Lama, M Eugenia; Gomà, Montserrat; Fulladosa, Xavier; Carrera, Marta; Hueso, Miguel; Grinyó, Josep M; Serón, Daniel

2005-11-01

The presence of chronic allograft nephropathy (CAN) in protocol biopsies is negatively associated with graft survival. Although recent studies have indicated that the resistive index (RI) is a predictor of graft failure, it does not correlate with CAN in stable grafts. We therefore studied the relationship between RI and CAN and examined the predictive value of both parameters on graft outcome. Included were patients transplanted between 1997 and 2002 and who had protocol biopsies and RI determinations. Renal lesions were blindly evaluated according to Banff 97 criteria. Mean glomerular volume, cortical interstitial volume fraction and intimal arterial volume fraction were estimated using a point counting technique. RI was determined before biopsy in at least two different renal locations. The outcome variable was defined as graft failure or a 30% serum creatinine increase between protocol biopsy and last follow-up. Eighty-seven patients were included. RI correlated with recipient age (R = 0.52, P < 0.0001), diastolic blood pressure (R = -0.36, P = 0.0006), pulse pressure index (R = 0.27, P = 0.009) and g-score for histological glomerulitis (rho = 0.30, P = 0.0054), but there were no correlations between RI and chronic Banff scores or any morphometric parameter. The presence of CAN (relative risk, 3.5; 95% confidence interval 1.2-10.2; P = 0.02) but not RI was associated with the outcome variable. RI was associated with surrogate measures of vascular compliance such as recipient age and pulse pressure index but not with chronic allograft damage, even when it was evaluated by histomorphometry. Our results indicate that histology may be superior to RI in predicting graft function deterioration, at least in patients with stable renal function.

Structure factor of blends of solvent-free nanoparticle-organic hybrid materials: density-functional theory and small angle X-ray scattering.

PubMed

Yu, Hsiu-Yu; Srivastava, Samanvaya; Archer, Lynden A; Koch, Donald L

2014-12-07

We investigate the static structure factor S(q) of solvent-free nanoparticle-organic hybrid materials consisting of silica nanocores and space-filling polyethylene glycol coronas using a density-functional theory and small angle X-ray scattering measurements. The theory considers a bidisperse suspension of hard spheres with different radii and tethered bead-spring oligomers with different grafting densities to approximate the polydispersity effects in experiments. The experimental systems studied include pure samples with different silica core volume fractions and the associated mean corona grafting densities, and blends with different mixing ratios of the pure samples, in order to introduce varying polydispersity of corona grafting density. Our scattering experiments and theory show that, compared to the hard-sphere suspension with the same core volume fraction, S(q) for pure samples exhibit both substantially smaller values at small q and stronger particle correlations corresponding to a larger effective hard core at large q, indicating that the tethered incompressible oligomers enforce a more uniform particle distribution, and the densely grafted brush gives rise to an additional exclusionary effect between the nanoparticles. According to the theory, polydispersity in the oligomer grafting density controls the deviation of S(q) from the monodisperse system at smaller q, and the interplay of the enhanced effective core size and the entropic attraction among the particles is responsible for complex variations in the particle correlations at larger q. The successful comparison between the predictions and the measurements for the blends further suggests that S(q) can be used to assess the uniformity of grafting density in polymer-grafted nanoparticle materials.

Pediatric Renal Transplantation in Oman: A Single-center Experience

PubMed Central

Al Riyami, Mohamed S.; Al Saidi, Sulaiman; Al Ghaithi, Badria; Al Maskari, Anisa; Lala, Sadiq; Mohsin, Nabil; Hirshikesan, Lekha; Al Kalbani, Naifain

2018-01-01

Objectives This study sought to report 22 years experience in pediatric kidney transplantation in Oman. Methods Electronic charts of all Omani children below 13 years of age who received a kidney transplant from January 1994 to December 2015 were reviewed. Data collected included patient demographics, etiology of end-stage kidney disease, modality and duration of dialysis, donor type, complication of kidney transplantation (including surgical complications, infections, graft rejection) graft and patient survival, and duration of follow-up. Results During the study period transplantation from 27 living related donors (LRDs), 42 living unrelated donors (LURDs), also referred to as commercial transplant, and one deceased donor were performed. The median age at transplantation was nine years for both groups. The most common primary diagnosis was congenital anomalies of the kidney and urinary tract in 32.8% of patients followed by familial nephrotic syndrome in 20.0% and polycystic kidney disease in 18.5%. Almost half the patients were on hemodialysis before transplantation, 35.7% were on peritoneal dialysis, and 14.2% received preemptive renal transplantation. Children who received LURD kidneys had high surgical complications (42.8%) compared to the LRDs group (17.8%). Five patients from LURDs group had early graft nephrectomy and four patients developed non-graft function or delayed graft function. In addition, patients in the LURDs group had a higher incidence of hypertension and acute rejection. Graft and patient survival were both better in the LRDs than the LURDs group. Conclusions Although our pediatric kidney transplant program is a young program it has had successful patient outcomes comparable to international programs. Our study provides evidence that in addition to legal and ethical issues with commercial transplant, it also carries significantly higher morbidity and reduced graft and patient survival. PMID:29467993

Cytocompatibility of polyethylene grafted with triethylenetetramine functionalized carbon nanoparticles

NASA Astrophysics Data System (ADS)

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

2017-11-01

Various carbon nanostructures are widely researched as scaffolds for tissue engineering. We evaluated the surface properties and cell-substrate interactions of carbon nanoparticles functionalized with triethylenetetramine (CNPs) grafted polymer film. Two forms of polyethylene (HDPE, LDPE) were treated in an inert argon plasma discharge and, subsequently, grafted with CNPs. The surface properties were studied using multiple methods, including Raman spectroscopy, goniometry, atomic force microscopy, X-ray photoelectron spectroscopy and electrokinetic analysis. Cell-substrate interactions were determined in vitro by studying adhesion, proliferation and viability of vascular smooth muscle cells (VSMCs) from the aorta of a rat. Cell-substrate interactions on pristine and modified substrates were compared to standard tissue culture polystyrene. Our results show that CNPs affect surface morphology and wettability and therefore adhesion, proliferation and viability of cultured muscle cells.

Effect of graft choice on the outcome of revision anterior cruciate ligament reconstruction in the Multicenter ACL Revision Study (MARS) Cohort

PubMed Central

Wright, Rick W.; Huston, Laura J.; Haas, Amanda K.; Spindler, Kurt P.; Nwosu, Sam K.; Allen, Christina R.; Anderson, Allen F.; Cooper, Daniel E.; DeBerardino, Thomas M.; Dunn, Warren R.; Lantz, Brett (Brick) A.; Stuart, Michael J.; Garofoli, Elizabeth A.; Albright, John P.; Amendola, Annunziato (Ned); Andrish, Jack T.; Annunziata, Christopher C.; Arciero, Robert A.; Bach, Bernard R.; Baker, Champ L.; Bartolozzi, Arthur R.; Baumgarten, Keith M.; Bechler, Jeffery R.; Berg, Jeffrey H.; Bernas, Geoffrey A.; Brockmeier, Stephen F.; Brophy, Robert H.; Bush-Joseph, Charles A.; Butler, J. Brad; Campbell, John D.; Carey, James L.; Carpenter, James E.; Cole, Brian J.; Cooper, Jonathan M.; Cox, Charles L.; Creighton, R. Alexander; Dahm, Diane L.; David, Tal S.; Flanigan, David C.; Frederick, Robert W.; Ganley, Theodore J.; Gatt, Charles J.; Gecha, Steven R.; Giffin, James Robert; Hame, Sharon L.; Hannafin, Jo A.; Harner, Christopher D.; Harris, Norman Lindsay; Hechtman, Keith S.; Hershman, Elliott B.; Hoellrich, Rudolf G.; Hosea, Timothy M.; Johnson, David C.; Johnson, Timothy S.; Jones, Morgan H.; Kaeding, Christopher C.; Kamath, Ganesh V.; Klootwyk, Thomas E.; Levy, Bruce A.; Ma, C. Benjamin; Maiers, G. Peter; Marx, Robert G.; Matava, Matthew J.; Mathien, Gregory M.; McAllister, David R.; McCarty, Eric C.; McCormack, Robert G.; Miller, Bruce S.; Nissen, Carl W.; O'Neill, Daniel F.; Owens, Brett D.; Parker, Richard D.; Purnell, Mark L.; Ramappa, Arun J.; Rauh, Michael A.; Rettig, Arthur C.; Sekiya, Jon K.; Shea, Kevin G.; Sherman, Orrin H.; Slauterbeck, James R.; Smith, Matthew V.; Spang, Jeffrey T.; Svoboda, Steven J.; Taft, Timothy N.; Tenuta, Joachim J.; Tingstad, Edwin M.; Vidal, Armando F.; Viskontas, Darius G.; White, Richard A.; Williams, James S.; Wolcott, Michelle L.; Wolf, Brian R.; York, James J.

2015-01-01

Background Most surgeons believe that graft choice for ACL reconstruction is an important factor related to outcome. Although graft choice may be limited in the revision setting based on previously used grafts, it is still felt to be important. Hypothesis The purpose of this study was to determine if revision ACL graft choice predicts outcomes related to sports function, activity level, OA symptoms, graft re-rupture, and reoperation at two years following revision reconstruction. We hypothesized that autograft use would result in increased sports function, increased activity level, and decreased OA symptoms (as measured by validated patient reported outcome instruments). Additionally, we hypothesized that autograft use would result in decreased graft failure and reoperation rate 2 years following revision ACL reconstruction. Study Design Prospective cohort study; Level of evidence, 2. Methods Revision ACL reconstruction patients were identified and prospectively enrolled by 83 surgeons over 52 sites. Data collected included baseline demographics, surgical technique and pathology, and a series of validated patient reported outcome instruments (IKDC, KOOS, WOMAC, and Marx activity rating score). Patients were followed up at 2 years, and asked to complete the identical set of outcome instruments. Incidence of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft re-rupture, and reoperation rate at 2 years following revision surgery. Results 1205 patients were successfully enrolled with 697 (58%) males. Median age was 26. In 88% this was their first revision. 341 (28%) were undergoing revision by the surgeon that had performed the previous reconstruction. 583 (48%) underwent revision reconstruction utilizing an autograft, 590 (49%) allograft, and 32 (3%) both autograft and allograft. Median time since their last ACL reconstruction was 3.4 years. Questionnaire follow-up was obtained on 989 subjects (82%), while phone follow-up was obtained on 1112 subjects (92%). The IKDC, KOOS, and WOMAC scores (with the exception of the WOMAC stiffness subscale) all significantly improved at the two year follow-up time point (p<0.001). In contrast, the two year MARX activity scale demonstrated a significant decrease from the initial score at enrollment (p<0.001). Graft choice proved to be a significant predictor of 2 year IKDC scores (p=0.017). Specifically, the use of an autograft for revision reconstruction predicted improved score on the IKDC [p=0.045; Odds Ratio (OR) = 1.31; 95% confidence intervals (CI) = 1.01, 1.70]. The use of an autograft predicted an improved on the KOOS subscale Sports and Recreation (p=0.037; OR=1.33; 95% CI=1.02, 1.73). Use of an autograft also predicted improved scores on the KOOS subscale Quality of Life (QOL) (p=0.031; OR=1.33; 95% CI=1.03, 1.73). For the KOOS Symptoms and ADL subscales, graft choice did not predict outcome score. Graft choice also proved to be a significant predictor of 2 year Marx activity level scores (p=0.012). Graft re-rupture was reported in 37/1112 (3.3%) of patients by their two year follow-up: 24 allografts, 12 autografts, and 1 allograft + autograft. Use of an autograft for revision resulted in patients 2.78 times less likely to sustain a subsequent graft rupture than if an allograft was utilized (p=0.047; 95% CI=1.01, 7.69). Conclusions Improved sports function and patient reported outcome measures are obtained when an autograft is utilized. Additionally, use of an autograft shows a decreased risk in graft re-rupture at two years follow-up. No differences were noted in rerupture or patient reported outcomes between soft tissue and bone-patellar tendon-bone grafts. Surgeon education regarding the findings in this study can result in potentially improved revision ACL reconstruction results for our patients. PMID:25274353

Biofouling-resistant ceragenin-modified materials and structures for water treatment

DOEpatents

Hibbs, Michael; Altman, Susan J.; Jones, Howland D. T.; Savage, Paul B.

2013-09-10

This invention relates to methods for chemically grafting and attaching ceragenin molecules to polymer substrates; methods for synthesizing ceragenin-containing copolymers; methods for making ceragenin-modified water treatment membranes and spacers; and methods of treating contaminated water using ceragenin-modified treatment membranes and spacers. Ceragenins are synthetically produced antimicrobial peptide mimics that display broad-spectrum bactericidal activity. Alkene-functionalized ceragenins (e.g., acrylamide-functionalized ceragenins) can be attached to polyamide reverse osmosis membranes using amine-linking, amide-linking, UV-grafting, or silane-coating methods. In addition, silane-functionalized ceragenins can be directly attached to polymer surfaces that have free hydroxyls.

Second-degree burns with six etiologies treated with autologous noncultured cell-spray grafting.

PubMed

Esteban-Vives, Roger; Choi, Myung S; Young, Matthew T; Over, Patrick; Ziembicki, Jenny; Corcos, Alain; Gerlach, Jörg C

2016-11-01

Partial and deep partial-thickness burn wounds present a difficult diagnosis and prognosis that makes the planning for a conservative treatment versus mesh grafting problematic. A non-invasive treatment strategy avoiding mesh grafting is often chosen by practitioners based on their clinical and empirical evidence. However, a delayed re-epithelialization after conservative treatment may extend the patient's hospitalization period, increase the risk of infection, and lead to poor functional and aesthetic outcome. Early spray grafting, using non-cultured autologous cells, is under discussion for partial and deep partial-thickness wounds to accelerate the re-epithelialization process, reducing the healing time in the hospital, and minimizing complications. To address planning for future clinical studies on this technology, suitable indications will be interesting. We present case information on severe second-degree injuries after gas, chemical, electrical, gasoline, hot water, and tar scalding burns showing one patient per indication. The treatment results with autologous non-cultured cells, support rapid, uncomplicated re-epithelialization with aesthetically and functionally satisfying outcomes. Hospital stays averaged 7.6±1.6 days. Early autologous cell-spray grafting does not preclude or prevent simultaneous or subsequent traditional mesh autografting when indicated on defined areas of full-thickness injury. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Extraction of palm tree cellulose and its functionalization via graft copolymerization.

PubMed

Al-Hoqbani, Abdulmajeed A; Abdel-Halim, E S; Al-Deyab, Salem S

2014-09-01

The work in this paper was planned with the aim of extracting the cellulosic component of palm tree waste and functionalizing this cellulose through graft copolymerization with acrylic acid. The cellulose extraction included hot alkali treatment with aqueous sodium hydroxide to remove the non-cellulosic binding materials. The alkali treatment was followed by an oxidative bleaching using peracid/hydrogen peroxide mixture with the aim of removing the rest of non-cellulosic materials to improve the fiber hydrophilicity and accessibility towards further grafting reaction. Optimum conditions for cellulose extraction are boiling in 5% (W/V) NaOH in a material to liquor ratio of 1:20 for 1 h then bleaching with 60 ml/l bleaching mixture at initial pH value of 6.5 for 30 min. The pH of the bleaching medium is turned to the alkaline range 11 and bleaching continues for extra 30 min. Graft copolymerization reaction was initiated by potassium bromate/thiourea dioxide redox system. Optimum conditions for grafting are 30 mmol of potassium bromate, 30 mmol of thiourea dioxide and 150 g of acrylic acid (each per 100 g of cellulose). The polymerization reaction was carried out for 120 min at 50°C using a material to liquor ratio of 1:20. Copyright © 2014 Elsevier B.V. All rights reserved.

Deproteinised natural rubber latex grafted poly(dimethylaminoethyl methacrylate) - poly(vinyl alcohol) blend membranes: Synthesis, properties and application.

PubMed

Jayadevan, Janisha; Alex, Rosamma; Gopalakrishnapanicker, Unnikrishnan

2018-02-01

Natural rubber latex was initially deproteinised (DNRL) and then subjected to physicochemical modifications to make high functional membranes for drug delivery applications. Initially, DNRL was prepared by incubating with urea, sodiumdodecylsulphate and acetone followed by centrifugation. The deproteinisation was confirmed by CHN analysis. The DNRL was then chemically modified by grafting (dimethylaminoethyl methacrylate) onto NR particles by using a redox initiator system viz; cumene hydroperoxide/tetraethylenepentamine, followed by dialysis for purification. The grafting was confirmed by dynamic light scattering, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The grafted system was blended with a hydrophilic adhesive polymer PVA and casted into membranes. The membranes after blending showed enhanced mechanical properties with a threshold concentration of PVA. The moisture uptake, swelling and water contact angle experiments indicated an increased hydrophilicity with an increased PVA content in the blend membranes. The grafted DNRL possessed significant antibacterial property which has been found to be retained in the blended form. A notable decrease in cytotoxicity was observed for the modified DNRL membranes than the bare DNRL membranes. The in-vitro drug release studies using rhodamine B as a model drug, confirmed the utility of the prepared membranes to function as a drug delivery matrix. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of donor treatment with hydrogen on lung allograft function in rats.

PubMed

Kawamura, Tomohiro; Huang, Chien-Sheng; Peng, Ximei; Masutani, Kosuke; Shigemura, Norihisa; Billiar, Timothy R; Okumura, Meinoshin; Toyoda, Yoshiya; Nakao, Atsunori

2011-08-01

Because inhaled hydrogen provides potent anti-inflammatory and antiapoptotic effects against acute lung injury, we hypothesized that treatment of organ donors with inhaled hydrogen during mechanical ventilation would decrease graft injury after lung transplantation. Orthotopic left lung transplants were performed using a fully allogeneic Lewis to Brown Norway rat model. The donors were exposed to mechanical ventilation with 98% oxygen plus 2% nitrogen or 2% hydrogen for 3 h prior to harvest, and the lung grafts underwent 4 h of cold storage in Perfadex (Vitrolife, Göteborg, Sweden). The graft function, histomorphologic changes, and inflammatory reactions were assessed. The combination of mechanical ventilation and prolonged cold ischemia resulted in marked deterioration of gas exchange when the donors were ventilated with 2% nitrogen/98% oxygen, which was accompanied by upregulation of proinflammatory cytokines and proapoptotic molecules. These lung injuries were attenuated significantly by ventilation with 2% hydrogen. Inhaled hydrogen induced heme oxygenase-1, an antioxidant enzyme, in the lung grafts prior to implantation, which might contribute to protective effects afforded by hydrogen. Preloaded hydrogen gas during ventilation prior to organ procurement protected lung grafts effectively from ischemia/reperfusion-induced injury in a rat lung transplantation model. Copyright © 2011 Mosby, Inc. All rights reserved.

Early experience and results of bone graft enriched with autologous platelet gel for recalcitrant nonunions of lower extremity.

PubMed

Chiang, Chao-Ching; Su, Chen-Yao; Huang, Ching-Kuei; Chen, Wei-Ming; Chen, Tain-Hsiung; Tzeng, Yun-Hsuan

2007-09-01

Refractory nonunions of the tibia or femur are physically and mentally devastating conditions for the patients, and the treatment is challenging for orthopedic surgeons. The goal of this study was to assess the feasibility and outcome of surgical treatment in recalcitrant nonunions of a lower extremity with bone graft enriched with autologous platelet gel (APG). Twelve patients with four femoral and eight tibial atrophic nonunions after multiple prior procedures were included. All of them were treated with the bone grafting procedures with autograft complex enriched with APG. They were evaluated with radiographs, bone mineral density for bony healing process, and the Short-Form 36 Health Survey for functional outcome. Of the 12 patients, 11 healed at an average of 19.7 weeks after the first attempt and 1 healed after the second attempt at 21 weeks. The bone mineral density continued to increase steadily from early healing to the remodeling phase. Functional status was greatly improved at an average follow-up of 32.4 months. The results of this preliminary study implied the possible potential of bone graft enriched with APG in the treatment of recalcitrant nonunions of the lower extremity. More research is necessary to clarify its role in augmentation of bone graft to enhance healing of nonunion.

Impacts of donor-specific anti-HLA antibodies and antibody-mediated rejection on outcomes after intestinal transplantation in children.

PubMed

Petit, L-M; Rabant, M; Canioni, D; Suberbielle-Boissel, C; Goulet, O; Chardot, C; Lacaille, F

2017-03-01

AMR is a risk factor for graft failure after SBTx. We studied impact of DSAs and AMR in 22 children transplanted between 2008 and 2012 (11 isolated SBTx, 10 liver inclusive Tx, and one modified multivisceral Tx). Three patients never developed DSA, but DSAs were found in seven in the pre-Tx period and de novo post-Tx in 19 children. Pathology revealed cellular rejection (15/19), with vascular changes and C4d+. Patients were treated with IV immunoglobulins, plasmapheresis, and steroids. Rescue therapy included antithymocyte globulins, rituximab, eculizumab, and bortezomib. Pathology and graft function normalized in 13 patients, graft loss occurred in two, and death in seven. At the end of the follow-up, 15 children were alive (68%), 13 with functioning graft (59%). Prognosis factors for poor outcome after Tx were the presence of symptoms at AMR suspicion (P +.033). DSAs were often found following SBTx, mostly de novo. Resistant ACR or severe AMR is still difficult to differentiate, with a high need for immunosuppression in both. DSAs may precede development of severe disease and pathology features on the graft: relationship and correlation need to be better investigated with larger groups before and after Tx. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Functional and surface-active membranes from poly(vinylidene fluoride)-graft-poly(acrylic acid) prepared via RAFT-mediated graft copolymerization.

PubMed

Ying, L; Yu, W H; Kang, E T; Neoh, K G

2004-07-06

Poly (vinylidene fluoride) (PVDF) with "living" poly (acrylic acid) (PAAc) side chains (PVDF-g-PAAc) was prepared by reversible addition-fragmentation chain transfer (RAFT)-mediated graft copolymerization of acrylic acid (AAc) with the ozone-pretreated PVDF. The chemical composition and structure of the copolymers were characterized by elemental analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The copolymer could be readily cast into pH-sensitive microfiltration (MF) membranes with enriched living PAAc graft chains on the surface (including the pore surfaces) by phase inversion in an aqueous medium. The surface composition of the membranes was determined by X-ray photoelectron spectroscopy. The morphology of the membranes was characterized by scanning electron microscopy. The pore size distribution of the membranes was found to be much more uniform than that of the corresponding membranes cast from PVDF-g-PAAc prepared by the "conventional" free-radical graft copolymerization process. Most important of all, the MF membranes with surface-tethered PAAc macro chain transfer agents, or the living membrane surfaces, could be further functionalized via surface-initiated block copolymerization with N-isopropylacrylamide (NIPAAM) to obtain the PVDF-g-PAAc-b-PNIPAAM MF membranes, which exhibited both pH- and temperature-dependent permeability to aqueous media.

Synthesis of antibacterial surfaces by plasma grafting of zinc oxide based nanocomposites onto polypropylene.

PubMed

de Rancourt, Yoann; Couturaud, Benoit; Mas, André; Robin, Jean Jacques

2013-07-15

Antibacterial polymer surfaces were designed using ZnO nanoparticles as a bactericide. Mineral encapsulated nanoparticles were grafted onto activated polymer surfaces through their shells. Polypropylene (PP) surfaces were treated using an innovative process coupling core-shell technology and plasma grafting, well-known techniques commonly used to obtain active surfaces for biomedical applications. First, ZnO nanoparticles were encapsulated by (co)polymers: poly(acrylic acid) (PAA) or a poly(methyl methacrylate-co-methacrylic acid) copolymer [P(MMA-MA)]. Second, PP substrates were activated using plasma treatment. Finally, plasma-treated surfaces were immersed in solutions containing the encapsulated nanoparticles dispersed in an organic solvent and allowed to graft onto it. The presence of nanoparticles on the substrates was demonstrated using Fourier-Transform Infrared Spectroscopy (FTIR) analysis, Scanning Electron Microspcopy (SEM)/Energy-Dispersive X-ray (EDX), and Atomic Force Microscopy (AFM) studies. Indeed, the ZnO-functionalized substrates exhibited an antibacterial response in Escherichia coli adhesion tests. Moreover, this study revealed that, surprisingly, native ZnO nanoparticles without any previous functionalization could be directly grafted onto polymeric surfaces through plasma activation. The antibacterial activity of the resulting sample was shown to be comparable to that of the other samples. Copyright © 2013 Elsevier Inc. All rights reserved.

Surface modification of silicon wafer by grafting zwitterionic polymers to improve its antifouling property

NASA Astrophysics Data System (ADS)

Sun, Yunlong; Chen, Changlin; Xu, Heng; Lei, Kun; Xu, Guanzhe; Zhao, Li; Lang, Meidong

2017-10-01

Silicon (111) wafer was modified by triethoxyvinylsilane containing double bond as an intermedium, and then P4VP (polymer 4-vinyl pyridine) brush was "grafted" onto the surface of silicon wafer containing reactive double bonds by adopting the "grafting from" way and Si-P4VP substrate (silicon wafer grafted by P4VP) was obtained. Finally, P4VP brush of Si-P4VP substrate was modified by 1,3-propanesulfonate fully to obtain P4VP-psl brush (zwitterionic polypyridinium salt) and the functional Si-P4VP-psl substrate (silicon wafer grafted by zwitterionic polypyridinium salt based on polymer 4-vinyl pyridine) was obtained successfully. The antifouling property of the silicon wafer, the Si-P4VP substrate and the Si-P4VP-psl substrate was investigated by using bovine serum albumin, mononuclear macrophages (RAW 264.7) and Escherichia coli (E. coli) ATTC25922 as model bacterium. The results showed that compared with the blank sample-silicon wafer, the Si-P4VP-psl substrate had excellent anti-adhesion ability against bovine serum albumin, cells and bacterium, due to zwitterionic P4VP-psl brush (polymer 4-vinyl pyridine salt) having special functionality like antifouling ability on biomaterial field.

Systematic review of kidney transplantation functional predictors.

PubMed

Miret Alomar, E; Trilla Herrera, E; Lorente Garcia, D; Regis Placido, L; López Del Campo, R; Cuadras Solé, M; Pont Castellana, T; Moreso Mateos, F; Serón Micas, D; Morote Robles, J

2018-05-01

Kidney transplantation from donors with expanded criteria has increased the pool of kidneys at the cost of a higher risk of short and long-term graft dysfunction. The main issue lies in determining which kidneys will offer acceptable function and survival compared with the risk represented by surgery and subsequent immunosuppression. The objective of our article is to review the current evidence on the tools for predicting the functionality of kidney transplantation from cadaveric donors with expanded criteria and determining the validity for their use in standard practice. We conducted a systematic literature review according to the PRISM criteria, through Medline (http://www.ncbi.nlm.nih.gov) and using the keywords (in isolation or in conjunction) "cadaveric renal transplantation; kidney graft function appraisal, graft function predictors". We selected prospective and retrospective series and review articles. A total of 375 articles were analysed, 39 of which were ultimately selected for review. The predictors of functionality include the following: The donor risk indices; the calculation of the renal functional weight or the assessment of the nephronic mass; the measurement of vascular resistances during perfusion in hypothermia; the measurement of the donor's biomarkers in urine and in the perfusion liquid; the measurement of functional and reperfusion parameters in normothermia; and the measurement of morphological parameters (microscopic and macroscopic) of the target organ. In this article, we present an explanatory summary of each of these parameters, as well as their most recent evidence on this issue. None of the reviewed parameters in isolation could reliably predict renal function and graft survival. There is a significant void in terms of the macroscopic assessment of kidney transplantation. We need to continue developing predictors of renal functionality to accurately define the distribution of each currently available donor kidney. Copyright © 2017 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Epoxy and Silicone Optical Nanocomposites Filled with Grafted Nanoparticles

NASA Astrophysics Data System (ADS)

Tao, Peng

Polymer nanocomposites, as a technologically important class of materials, exhibit diverse functional properties, and are used for applications ranging from structural and biomedical to electronic and optical. The properties of polymer nanocomposites are determined, in part, by the chemical composition of the polymer matrix and the nanofillers. Their properties are also sensitive to the geometry and size of the nanofillers, and to spatial distribution of the fillers. Control of the nanoparticle size and dispersion within a given polymer provides opportunities to tailor and optimize the properties of nanocomposites for specific application. For optical applications such as encapsulation of light emitting diodes (LEDs), polymer nanocomposites filled with homogeneously dispersed nanoparticles would endow the polymer encapsulant with new functionality without sacrificing optical transparency. To this end, this thesis focuses on developing a simple and versatile approach towards the fabrication of epoxy and silicone transparent nanocomposites using matrix compatible chain-grafted nanoparticles as fillers, and studying the optical properties of the nanocomposites. The surface chemistry and grafted polymer chain design have been shown to play an important role in determining the dispersion state of the grafted nanoparticles and hence the final optical properties of the nanocomposites. To prepare transparent epoxy nanocomposites, poly (glycidyl methacrylate) (PGMA) chains were grafted onto the optical nanoparticle surfaces via a combined phosphate ligand exchange process and azide-alkyne "click" chemistry. The dispersion behavior of PGMA-grafted nanoparticles within the epoxy matrix was investigated by systematically varying the grafting density and grafted chain length. It was found that within the small molecular weight epoxy resins, the dispersion states are more sensitive to the grafting density than the molecular weight of grafted chains. With high grafting densities, the grafted PGMA brushes effectively screen the van der Waals attraction between the particles, and homogenous nanoparticle dispersions of grafted nanoparticles were obtained. Transparent high refractive index TiO2/epoxy thin film and bulk nancomposites were obtained by dispersing PGMA brushes-grafted TiO2 nanoparticles into a commercial epoxy matrix. The refractive index of the nanocomposites showed a linear dependence on the volume fraction of TiO2 nanoparticles and the optical transparency could be generally described by the Rayleigh scattering model. This powerful dispersing technique was further employed to make visibly transparent, UV/IR blocking ITO/epoxy nanocomposites which can be easily applied onto glass and plastic substrates as energy saving optical coating materials. To produce transparent silicone nanocomposites, we directly coupled phosphate-terminated PDMS chains onto the optical nanoparticle surface. It was observed that the mono-modal PDMS-grafted particles usually formed agglomerates within silicone matrices, whereas the bimodal PDMS-grafted particles were able to be individually dispersed even within high molecular weight matrices. Transparent high refractive index bulk TiO2/silicone nanocomposites were successfully prepared by filling with bimodal PDMS-grafted TiO2 nanoparticles. Furthermore, we used the PDMS-grafted TiO2/silicone nanocomposite as a model system to create a methodology to predict and control the dispersion behavior of grafted nanoparticles. The good agreement between experimental observation of dispersion of mono-modal and bimodal grafted particles and theoretical prediction would better guide future experiments and lead to predictability in polymer composite design. Finally, the bimodal grafted chain design was implemented in the preparation of transparent and luminescent CdSe/silicone nanocomposites with potential application as non-scattering light conversion materials for LEDs. The homogeneous dispersion of bimodal PDMS-grafted CdSe quantum dots not only minimizes the transparency loss due to scattering, but also benefits the uniformity and long-term stability of photoluminescence of the nanocomposites.

Fresh Osteochondral Allograft Transplantation: Is Graft Storage Time Associated With Clinical Outcomes and Graft Survivorship?

PubMed

Schmidt, Kenneth J; Tírico, Luís E; McCauley, Julie C; Bugbee, William D

2017-08-01

Regulatory concerns and the popularity of fresh osteochondral allograft (OCA) transplantation have led to a need for prolonged viable storage of osteochondral grafts. Tissue culture media allow a longer storage time but lead to chondrocyte death within the tissue. The long-term clinical consequence of prolonged storage is unknown. Patients transplanted with OCAs with a shorter storage time would have lower failure rates and better clinical outcomes than those transplanted with OCAs with prolonged storage. Cohort study; Level of evidence, 3. A matched-pair study was performed of 75 patients who received early release grafts (mean storage, 6.3 days [range, 1-14 days]) between 1997 and 2002, matched 1:1 by age, diagnosis, and graft size, with 75 patients who received late release grafts (mean storage time, 20.0 days [range, 16-28 days]) from 2002 to 2008. The mean age was 33.5 years, and the median graft size was 6.3 cm 2 . All patients had a minimum 2-year follow-up. Evaluations included pain, satisfaction, function, failures, and reoperations. Outcome measures included the modified Merle d'Aubigné-Postel (18-point) scale, International Knee Documentation Committee (IKDC) form, and Knee Society function (KS-F) scale. Clinical failure was defined as revision OCA transplantation or conversion to arthroplasty. Among patients with grafts remaining in situ, the mean follow-up was 11.9 years (range, 2.0-16.8 years) and 7.8 years (range, 2.3-11.1 years) for the early and late release groups, respectively. OCA failure occurred in 25.3% (19/75) of patients in the early release group and 12.0% (9/75) of patients in the late release group ( P = .036). The median time to failure was 3.5 years (range, 1.7-13.8 years) and 2.7 years (range, 0.3-11.1 years) for the early and late release groups, respectively. The 5-year survivorship of OCAs was 85% for the early release group and 90% for the late release group ( P = .321). No differences in postoperative pain and function were noted between the groups. Ninety-one percent of the early release group and 93% of the late release group reported satisfaction with OCA results. The transplantation of OCA tissue with prolonged storage is safe and effective for large osteochondral lesions of the knee and has similar clinical outcomes and satisfaction to the transplantation of early release grafts.

Grafting of GMA and some comonomers onto chitosan for controlled release of diclofenac sodium.

PubMed

Sharma, Rajeev Kr; Lalita; Singh, Anirudh P; Chauhan, Ghanshyam S

2014-03-01

In order to develop pH sensitive hydrogels for controlled drug release we have graft copolymerized glycidyl methacrylate (GMA) with comonomers acrylic acid, acrylamide and acrylonitrile, onto chitosan (Ch) by using potassium persulphate (KPS) as free radical initiator in aqueous solution. The optimum percent grafting for GMA was recorded for 1g chitosan at [KPS]=25.00 × 10(-3)mol/L, [GMA]=0.756 × 10(-3)mol/L, reaction temperature=60 °C and reaction time=1h in 20 mL H2O. Binary monomers were grafted for five different concentrations at optimum grafting conditions evaluated for GMA alone onto chitosan. The graft copolymers were characterized by FTIR, XRD, TGA and SEM. The swelling properties of chitosan and graft copolymers were investigated at different pH to define their end uses in sustained release of an anti-inflammatory drug, diclofenac sodium. Percent drug release w.r.t. drug loaded in polymeric sample was studied as function of time in buffer solutions of pH 2.0 and 7.4. In vitro release data was analyzed using Fick's Law. Chitosan grafted with binary monomers, GMA-co-AAm and GMA-co-AN showed very good results for sustained release of drug at 7.4 pH. Copyright © 2014 Elsevier B.V. All rights reserved.

Bridging extra large defects of peripheral nerves: possibilities and limitations of alternative biological grafts from acellular muscle and Schwann cells.

PubMed

Keilhoff, Gerburg; Prätsch, Florian; Wolf, Gerald; Fansa, Hisham

2005-01-01

Defects of peripheral nerves are bridged with autologous nerve grafts. Tissue-engineered nerve grafts offer a laboratory-based alternative to overcome limited donor nerve availability. Our objective was to evaluate whether a graft made from acellular muscle enriched with cultivated Schwann cells can bridge extra large gaps where conventional conduits usually fail. Our well-established rat sciatic nerve model was used with an increased gap length of 50 mm. The conduits consisted of freeze-thawed or chemically extracted homologous acellular rat rectus muscles and implanted Schwann cells. Autologous nerve grafts were used for control purposes. Biocompatibility of the grafts was demonstrated by Schwann cell settlement, revascularization, and macrophage recruitment. After 12 weeks regeneration was assessed clinically, histologically, and morphometrically. The control group showed superior results regarding axon counts, histologic appearance, and functional recovery compared with the muscle grafts. The chemically extracted conduits completely failed to support nerve regeneration. They were not stable enough to bridge longer nerve gaps with an expanded regeneration time. On the basis of morphological parameters freeze-thawed muscle grafts were, however, able to support peripheral nerve regeneration even over the extralong distance of 50 mm, and therefore are of potential benefit for new therapeutic strategies.

Synthetic bone graft versus autograft or allograft for spinal fusion: a systematic review.

PubMed

Buser, Zorica; Brodke, Darrel S; Youssef, Jim A; Meisel, Hans-Joerg; Myhre, Sue Lynn; Hashimoto, Robin; Park, Jong-Beom; Tim Yoon, S; Wang, Jeffrey C

2016-10-01

The purpose of this review was to compare the efficacy and safety of synthetic bone graft substitutes versus autograft or allograft for the treatment of lumbar and cervical spinal degenerative diseases. Multiple major medical reference databases were searched for studies that evaluated spinal fusion using synthetic bone graft substitutes (either alone or with an autograft or allograft) compared with autograft and allograft. Randomized controlled trials (RCT) and cohort studies with more than 10 patients were included. Radiographic fusion, patient-reported outcomes, and functional outcomes were the primary outcomes of interest. The search yielded 214 citations with 27 studies that met the inclusion criteria. For the patients with lumbar spinal degenerative disease, data from 19 comparative studies were included: 3 RCTs, 12 prospective, and 4 retrospective studies. Hydroxyapatite (HA), HA+collagen, β-tricalcium phosphate (β-TCP), calcium sulfate, or polymethylmethacrylate (PMMA) were used. Overall, there were no differences between the treatment groups in terms of fusion, functional outcomes, or complications, except in 1 study that found higher rates of HA graft absorption. For the patients with cervical degenerative conditions, data from 8 comparative studies were included: 4 RCTs and 4 cohort studies (1 prospective and 3 retrospective studies). Synthetic grafts included HA, β-TCP/HA, PMMA, and biocompatible osteoconductive polymer (BOP). The PMMA and BOP grafts led to lower fusion rates, and PMMA, HA, and BOP had greater risks of graft fragmentation, settling, and instrumentation problems compared with iliac crest bone graft. The overall quality of evidence evaluating the potential use and superiority of the synthetic biological materials for lumbar and cervical fusion in this systematic review was low or insufficient, largely due to the high potential for bias and small sample sizes. Thus, definitive conclusions or recommendations regarding the use of these synthetic materials should be made cautiously and within the context of the limitations of the evidence.

MRI signal intensity of anterior cruciate ligament graft after transtibial versus anteromedial portal technique (TRANSIG): design of a randomized controlled clinical trial.

PubMed

Ruiter, Simeon J S; Brouwer, Reinoud W; Meys, Tim W G M; Slump, Cornelis H; van Raay, Jos J A M

2016-08-10

There are two primary surgical techniques to reconstruct the anterior cruciate ligament (ACL), transtibial (TT) technique and anteromedial portal (AMP) technique. Currently, there is no consensus which surgical technique elicits the best clinical and functional outcomes. MRI-derived measures of the signal intensity (SI) of the ACL graft have been described as an independent predictor of graft properties. The purpose of this study is to compare the MRI derived SI measurements of the ACL graft one year after ACL reconstruction, in order to compare the outcomes of both the AMP and TT ACL reconstruction technique. Thirty-six patients will be included in a randomized controlled trial. Patients who are admitted for primary unilateral ACL reconstruction will be included in the study. Exclusion criteria are a history of previous surgery on the ipsilateral knee, re-rupture of the ipsilateral ACL graft, associated ligamentous injuries or meniscal tear of the ipsilateral knee, unhealthy contralateral knee, contra-indications for MRI and a preference for one of the two surgical techniques and/or orthopaedic surgeon. Primary outcome is MRI Signal intensity ratio (SIR) of the ACL graft. Secondary outcome measures are the International Knee Documentation Committee (IKDC) Knee Examination Form,the Knee injury and Osteoarthritis Outcome Scores (KOOS) and the Anterior Cruciate Ligament OsteoArthritis Score (ACLOAS). Differences between MRI SIR assessment with the current MRI protocol (proton density weighted imaging protocol) and the additional T2*-weighted gradient-echo protocol will be assessed. There is no consensus regarding the TT or AMP ACL reconstruction technique. SI measurements with MRI have been used in other clinical studies for evaluation of the ACL graft and maturation after ACL reconstruction compared to clinical and functional outcomes. This randomized controlled trial has been designed to compare the TT technique with the AMP technique with the use of MRI SI of the graft after ACL reconstruction. Netherlands Trial Registry NTR5410 (registered on August 24, 2015).

Skin grafting impairs postsynaptic cutaneous vasodilator and sweating responses.

PubMed

Davis, Scott L; Shibasaki, Manabu; Low, David A; Cui, Jian; Keller, David M; Purdue, Gary F; Hunt, John L; Arnoldo, Brett D; Kowalske, Karen J; Crandall, Craig G

2007-01-01

This study tested the hypothesis that postsynaptic cutaneous vascular responses to endothelial-dependent and -independent vasodilators, as well as sweat gland function, are impaired in split-thickness grafted skin 5 to 9 months after surgery. Intradermal microdialysis membranes were placed in grafted and adjacent control skin, thereby allowing local delivery of the endothelial-dependent vasodilator, acetylcholine (ACh; 1 x 10(-7) to 1 x 10(-1) M at 10-fold increments) and the endothelial-independent nitric oxide donor, sodium nitroprusside (SNP; 5 x 10(-8) to 5 x 10(-2) M at 10-fold increments). Skin blood flow and sweat rate were simultaneously assessed over the semipermeable portion of the membrane. Cutaneous vascular conductance (CVC) was calculated from the ratio of laser Doppler-derived skin blood flow to mean arterial blood pressure. deltaCVC responses from baseline to these drugs were modeled via nonlinear regression curve fitting to identify the dose of ACh and SNP causing 50% of the maximal vasodilator response (EC50). A rightward shift in the CVC dose response curve for ACh was observed in grafted (EC50 = -2.61 +/- 0.44 log M) compared to adjacent control skin (EC50 = -3.34 +/- 0.46 log M; P = .003), whereas the mean EC50 for SNP was similar between grafted (EC50 = -4.21 +/- 0.94 log M) and adjacent control skin (EC50 = -3.87 +/- 0.65 log M; P = 0.332). Only minimal sweating to exogenous ACh was observed in grafted skin whereas normal sweating was observed in control skin. Increased EC50 and decreased maximal CVC responses to the exogenous administration of ACh suggest impairment of endothelial-dependent cutaneous vasodilator responses in grafted skin 5 to 9 months after surgery. Greatly attenuated sweating responses to ACh suggests either abnormal or an absence of functional sweat glands in the grafted skin.

Renal transplantation in patients with hepatitis C virus antibody. A long national experience

PubMed Central

Morales, Jose María; Marcén, Roberto; Andres, Amado; Domínguez-Gil, Beatriz; Campistol, Josep María; Gallego, Roberto; Gutierrez, Alex; Gentil, Miguel Angel; Oppenheimer, Federico; Samaniego, María Luz; Muñoz-Robles, Jorge; Serón, Daniel

2010-01-01

Background. Renal transplantation is the best therapy for patients with hepatitis C virus (HCV) infection with end-stage renal disease. Patient and graft survival are lower in the long term compared with HCV-negative patients. The current study evaluated the results of renal transplantation in Spain in a long period (1990–2002), focusing on graft failure. Methods. Data on the Spanish Chronic Allograft Nephropathy Study Group including 4304 renal transplant recipients, 587 of them with HCV antibody, were used to estimate graft and patient survival at 4 years with multivariate Cox models. Results. Among recipients alive with graft function 1 year post-transplant, the 4-year graft survival was 92.8% in the whole group; this was significantly better in HCV-negative vs HCV-positive patients (94.4% vs 89.5%, P < 0.005). Notably, HCV patients showed more acute rejection, a higher degree of proteinuria accompanied by a diminution of renal function, more graft biopsies and lesions of de novo glomerulonephritis and transplant glomerulopathy. Serum creatinine and proteinuria at 1 year, acute rejection, HCV positivity and systolic blood pressure were independent risk factors for graft loss. Patient survival was 96.3% in the whole group, showing a significant difference between HCV-negative vs HCV-positive patients (96.6% vs 94.5%, P < 0.05). Serum creatinine and diastolic blood pressure at 1 year, HCV positivity and recipient age were independent risk factors for patient death. Conclusions. Renal transplantation is an effective therapy for HCV-positive patients with good survival but inferior than results obtained in HCV-negative patients in the short term. Notably, HCV-associated renal damage appears early with proteinuria, elevated serum creatinine showing chronic allograft nephropathy, transplant glomerulopathy and, less frequently, HCV-associated de novo glomerulonephritis. We suggest that HCV infection should be recognized as a true risk factor for graft failure, and preventive measures could include pre-transplant therapy with interferon. PMID:20508864

A comparison of lamellar and penetrating keratoplasty outcomes: a registry study.

PubMed

Coster, Douglas J; Lowe, Marie T; Keane, Miriam C; Williams, Keryn A

2014-05-01

To investigate changing patterns of practice of keratoplasty in Australia, graft survival, visual outcomes, the influence of experience, and the surgeon learning curve for endothelial keratoplasty. Observational, prospective cohort study. From a long-standing national corneal transplantation register, 13 920 penetrating keratoplasties, 858 deep anterior lamellar keratoplasties (DALKs), and 2287 endokeratoplasties performed between January 1996 and February 2013 were identified. Kaplan-Meier functions were used to assess graft survival and surgeon experience, the Pearson chi-square test was used to compare visual acuities, and linear regression was used to examine learning curves. Graft survival. The total number of corneal grafts performed annually is increasing steadily. More DALKs but fewer penetrating grafts are being performed for keratoconus, and more endokeratoplasties but fewer penetrating grafts are being performed for Fuchs' dystrophy and pseudophakic bullous keratopathy. In 2012, 1482 grafts were performed, compared with 955 in 2002, translating to a requirement for 264 extra corneal donors across the country in 2012. Comparing penetrating grafts and DALKs performed for keratoconus over the same era, both graft survival (P <0.001) and visual outcomes (P <0.001) were significantly better for penetrating grafts. Survival of endokeratoplasties performed for Fuchs' dystrophy or pseudophakic bullous keratopathy was poorer than survival of penetrating grafts for the same indications over the same era (P <0.001). Visual outcomes were significantly better for penetrating grafts than for endokeratoplasties performed for Fuchs' dystrophy (P <0.001), but endokeratoplasties achieved better visual outcomes than penetrating grafts for pseudophakic bullous keratopathy (P <0.001). Experienced surgeons (>100 registered keratoplasties) achieved significantly better survival of endokeratoplasties (P <0.001) than surgeons who had performed fewer grafts (<100 registered keratoplasties). In the hands of experienced, high-volume surgeons, endokeratoplasty failures occurred even after 100 grafts had been performed. More corneal transplants, especially DALKs and endokeratoplasties, are being performed in Australia than ever before. Survival of DALKs and endokeratoplasties is worse than the survival of penetrating grafts performed for the same indications over the same timeframe. Many endokeratoplasties fail early, but the evidence for a surgeon learning curve is unconvincing. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

A new grafting technique for tympanoplasty: tympanoplasty with a boomerang-shaped chondroperichondrial graft (TwBSCPG).

PubMed

Dündar, Rıza; Soy, Fatih Kemal; Kulduk, Erkan; Muluk, Nuray Bayar; Cingi, Cemal

2014-10-01

The aim of this study was to introduce a new grafting technique in tympanoplasty that involves use of a boomerang-shaped chondroperichondrial graft (BSCPG). The anatomical and functional results were evaluated. A new tympanoplasty with boomerang-shaped chondroperichondrial graft (TwBSCPG) technique was used in 99 chronic otitis media patients with central or marginal perforation of the tympanic membrane and a normal middle ear mucosa. All 99 patients received chondroperichondrial cartilage grafts with a boomerang-shaped cartilage island left at the anterior and inferior parts. Postoperative follow-ups were conducted at months 1, 6, and 12. Preoperative and postoperative audiological examinations were performed and air-bone gaps were calculated according to the pure-tone averages (PTAs) of the patients. In the preoperative period, most (83.8%) air-bone gaps were ≥ 16 dB; after operating using the TwBSCPG technique, the air-bone gaps decreased to 0-10 dB in most patients (77.8%). In the TwBSCPG patients, the mean preoperative air-bone gap was 22.02 ± 6.74 dB SPL. Postoperatively, the mean postoperative air-bone gap was 8.70 ± 5.74 dB SPL. The TwBSCPG technique therefore decreased the postoperative air-bone gap compared to that preoperatively (p = 0.000, z = -8.645). At the 1-month follow-up, there were six graft perforations and one graft retraction. At the 6-month follow-up, there were nine graft perforations and three graft retractions. At 12 months, there were seven graft perforations and four graft retractions. During the first year after the boomerang tympanoplasty surgery, graft lateralization was not detected in any patient. Retractions were grade 1 according to the Sade classification and were localized to the postero-superior quadrant of the tympanic membrane. The TwBSCPG technique has benefits with respect to postoperative anatomical and audiological results. It prevents perforation of the tympanic membrane at the anterior quadrant and avoids graft lateralization due to placement of the graft under the manubrium mallei. Given these benefits, the TwBSCPG technique seems to be a good alternative for grafting in tympanoplasties.

Measurement of Gamma-Irradiated Corneal Patch Graft Thickness After Aqueous Drainage Device Surgery.

PubMed

de Luna, Regina A; Moledina, Ameera; Wang, Jiangxia; Jampel, Henry D

2017-09-01

Exposure of the tube of an aqueous drainage device (ADD) through the conjunctiva is a serious complication of ADD surgery. Although placement of gamma-irradiated sterile cornea (GISC) as a patch graft over the tube is commonly performed, exposures still occur. To measure GISC patch graft thickness as a function of time after surgery, estimate the rate of graft thinning, and determine risk factors for graft thinning. Cross-sectional study of graft thickness using anterior segment optic coherence tomography (AS-OCT) was conducted at the Wilmer Eye Institute at Johns Hopkins Hospital. A total of 107 patients (120 eyes, 120 ADDs) 18 years or older who underwent ADD surgery at Johns Hopkins with GISC patch graft between July 1, 2010, and October 31, 2016, were enrolled. Implantation of ADD with placement of GISC patch graft over the tube. Graft thickness vs time after ADD surgery and risk factors for undetectable graft. Of the 107 patients included in the analysis, the mean (SD) age of the cohort was 64 (16.2) years, 49 (45.8%) were male, and 43 (40.2%) were African American. The mean time of measurement after surgery was 1.7 years (range, 1 day to 6 years). Thinner grafts were observed as the time after surgery lengthened (β regression coefficient, -60 µm per year since surgery; 95% CI, -80 µm to -40 µm). The odds ratio of undetectable grafts per year after ADD surgery was 2.1 (95% CI, 1.5-3.0; P < .001). Age, sex, race, type of ADD, quadrant of ADD placement, diagnosis of uveitis or dry eye, and prior conjunctival surgery were not correlated with the presence or absence of the graft. Gamma-irradiated sterile corneal patch grafts do not always retain their integrity after ADD surgery. Data from this cross-sectional study showed that on average, the longer the time after surgery, the thinner the graft. These findings suggest that placement of a GISC patch graft is no guarantee against tube exposure, and that better strategies are needed for preventing this complication.

Patient-reported outcomes and health status associated with chronic graft-versus-host disease.

PubMed

Lee, Stephanie J; Onstad, Lynn; Chow, Eric J; Shaw, Bronwen E; Jim, Heather S L; Syrjala, Karen L; Baker, K Scott; Buckley, Sarah; Flowers, Mary E

2018-06-01

Chronic graft-versus-host disease occurs in 20-50% of allogeneic hematopoietic cell transplantation survivors. We surveyed patients about their quality of life, symptoms, health status, comorbid conditions and medication. Instruments included the Short-Form-36 (SF-36), the Patient-Reported Outcomes Measurement Information System (PROMIS) Global and PROMIS-29 scales and the Lee Chronic Graft-versus-Host Disease Symptom Scale. Functional status was measured by self-reported Karnofsky and work status. Of 3027 surveys sent to recipients surviving one or more years after transplantation, 1377 (45%) were returned. Among these, patients reported their chronic graft-versus-host disease was mild (n=257, 18.7%), moderate (n=110, 8.0%) or severe (n=25, 1.8%). Another 377 (27.4%) never had chronic graft-versus-host disease and 280 (20.3%) had chronic graft-versus-host disease but it resolved. We excluded 328 (23.8%) who did not answer the questions about chronic graft-versus-host disease. Patients who reported moderate or severe chronic graft-versus-host disease reported worse quality of life, lower performance status, a higher symptom burden and were more likely to be taking prescription medications for pain, anxiety and depression compared to those with resolved chronic graft-versus-host disease. Self-reported measures were similar between patients with resolved chronic graft-versus-host disease and those who never had it. Our data suggest that the PROMIS measures may be able to replace the SF-36 in chronic graft-versus-host disease assessment. Between 26.7-39.4% of people with active chronic graft-versus-host disease were unable to work due to health reasons, compared with 12.1% whose chronic graft-versus-host disease had resolved and 15.4% who never had chronic graft-versus-host disease. Mouth, eye and nutrition symptoms persisted after resolution of chronic graft-versus-host disease. These results show that better prevention of and treatment for chronic graft-versus-host disease is needed to improve survivorship after allogeneic transplantation. Copyright © 2018, Ferrata Storti Foundation.

Surface functionalization of mesoporous silica SBA-15 by liquid-phase grafting of zirconium phosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Sheng; Hagaman, Edward; Ma, Zhen

2010-01-01

The introduction of mesoporous silicas in the 1990s has offered new opportunities for the engineering of ordered catalytic nanoreactors, but the acid properties of mesoporous silicas are rather poor. Herein, mesoporous silica (SBA-15) surfaces were functionalized by zirconium phosphate via two methods recently developed in our group. Zr(OPr){sub 4} and POCl{sub 3} were used as appropriate precursors in both methods. The main difference between these methods lies in whether Zr(OPr){sub 4} is grafted onto SBA-15 first and POCl{sub 3} second (method 1) or the grafting process takes place in one pot, with SBA-15, Zr(OPr){sub 4}, and POCl{sub 3} altogether (methodmore » 2). More zirconium phosphate could be grafted by repeating the above procedures. The materials were characterized by ICP-OES, XRD, N{sub 2} adsorption-desorption, TEM, {sup 31}P and {sup 29}Si MAS NMR, and NH{sub 3}-TPD, and their applications in catalytic isopropanol dehydration, cumene cracking, and metal-ion adsorption were demonstrated. Aluminum phosphate-modified SBA-15 samples could be obtained via these two methods as well. This work enriches the family of metal phosphate-functionalized mesoporous silicas as new solid acid catalysts.« less

Surface functionalization of 3D glass-ceramic porous scaffolds for enhanced mineralization in vitro

NASA Astrophysics Data System (ADS)

Ferraris, Sara; Vitale-Brovarone, Chiara; Bretcanu, Oana; Cassinelli, Clara; Vernè, Enrica

2013-04-01

Bone reconstruction after tissue loosening due to traumatic, pathological or surgical causes is in increasing demand. 3D scaffolds are a widely studied solution for supporting new bone growth. Bioactive glass-ceramic porous materials can offer a three-dimensional structure that is able to chemically bond to bone. The ability to surface modify these devices by grafting biologically active molecules represents a challenge, with the aim of stimulating physiological bone regeneration with both inorganic and organic signals. In this research work glass ceramic scaffolds with very high mechanical properties and moderate bioactivity have been functionalized with the enzyme alkaline phosphatase (ALP). The material surface was activated in order to expose hydroxyl groups. The activated surface was further grafted with ALP both via silanization and also via direct grafting to the surface active hydroxyl groups. Enzymatic activity of grafted samples were measured by means of UV-vis spectroscopy before and after ultrasonic washing in TRIS-HCl buffer solution. In vitro inorganic bioactivity was investigated by soaking the scaffolds after the different steps of functionalization in a simulated body fluid (SBF). SEM observations allowed the monitoring of the scaffold morphology and surface chemical composition after soaking in SBF. The presence of ALP enhanced the in vitro inorganic bioactivity of the tested material.

Transplant tourism--a dangerous journey?

PubMed

Polcari, Anthony J; Hugen, Cory M; Farooq, Ahmer V; Holt, David R; Hou, Susan H; Milner, John E

2011-01-01

While the ethical aspects of transplant tourism have received much attention recently, less has been written about the medical safety of this practice. We retrospectively evaluated the outcomes of patients who purchased organs internationally and presented to our center for follow-up care. Baseline demographic characteristics were recorded. Post-operative outcomes including patient survival, graft survival, five-yr graft function, and complications were assessed. Eight patients who purchased international organs for transplant were identified. The country of transplant was China (n = 3), Pakistan (n = 3), India (n = 1), and the Philippines (n = 1). All patients were born in either Asia or the Middle East and traveled to the region of their ethnicity for transplantation. The mean time to presentation was 49 d post-operatively. The overall one- and two-yr patient survival rates were 87% and 75%, respectively. One patient died of miliary tuberculosis and another of Acinetobacter baumanii sepsis. There was one case of newly acquired hepatitis B infection. At last follow-up, all six surviving patients had functioning grafts with a mean creatinine level of 1.26 mg/dL at five yr. Although intermediate-term graft function is acceptable, the early morbidity and mortality among transplant tourists is high. These results suggest that the associated risks may not justify the trip. © 2010 John Wiley & Sons A/S.

Magnetic separation of encapsulated islet cells labeled with superparamagnetic iron oxide nano particles.

PubMed

Mettler, Esther; Trenkler, Anja; Feilen, Peter J; Wiegand, Frederik; Fottner, Christian; Ehrhart, Friederike; Zimmermann, Heiko; Hwang, Yong Hwa; Lee, Dong Yun; Fischer, Stefan; Schreiber, Laura M; Weber, Matthias M

2013-01-01

Islet cell transplantation is a promising option for the restoration of normal glucose homeostasis in patients with type 1 diabetes. Because graft volume is a crucial issue in islet transplantations for patients with diabetes, we evaluated a new method for increasing functional tissue yield in xenogeneic grafts of encapsulated islets. Islets were labeled with three different superparamagnetic iron oxide nano particles (SPIONs; dextran-coated SPION, siloxane-coated SPION, and heparin-coated SPION). Magnetic separation was performed to separate encapsulated islets from the empty capsules, and cell viability and function were tested. Islets labeled with 1000 μg Fe/ml dextran-coated SPIONs experienced a 69.9% reduction in graft volume, with a 33.2% loss of islet-containing capsules. Islets labeled with 100 μg Fe/ml heparin-coated SPIONs showed a 46.4% reduction in graft volume, with a 4.5% loss of capsules containing islets. No purification could be achieved using siloxane-coated SPIONs due to its toxicity to the primary islets. SPION labeling of islets is useful for transplant purification during islet separation as well as in vivo imaging after transplantation. Furthermore, purification of encapsulated islets can also reduce the volume of the encapsulated islets without impairing their function by removing empty capsules. © 2013 John Wiley & Sons A/S.

Graft downsizing during ex vivo lung perfusion: case report and technical notes.

PubMed

Nosotti, M; Rosso, L; Mendogni, P; Tosi, D; Palleschi, A; Righi, I; Froio, S; Valenza, F; Santambrogio, L

2014-09-01

Among patients with respiratory insufficiency awaiting lung transplantation, small adult patients have a lower opportunity of receiving size-matched pulmonary grafts, because of the shortage of donors, particularly those of small size. Reducing the size of an oversized graft is one of the methods to increase the donor pool; similarly, ex vivo lung perfusion is an emerging technique aimed toward the same purpose. We describe how we combined the 2 techniques (lobar transplantation plus contralateral nonanatomic graft reduction during ex vivo lung perfusion) to overcome graft shortage in a clinical case. For the 1st time, this case report demonstrates that surgical manipulation during ex vivo lung perfusion does not affect the functional improvement in a lung previously judged to be not suitable for transplantation. The 6-month follow-up results are similar to those of standard bilateral lung transplantation. Copyright © 2014 Elsevier Inc. All rights reserved.

Alveolar ridge preservation of an extraction socket using autogenous tooth bone graft material for implant site development: prospective case series

PubMed Central

Yun, Pil-Young; Um, In-Woong; Lee, Hyo-Jung; Yi, Yang-Jin; Bae, Ji-Hyun; Lee, Junho

2014-01-01

This case series evaluated the clinical efficacy of autogenous tooth bone graft material (AutoBT) in alveolar ridge preservation of an extraction socket. Thirteen patients who received extraction socket graft using AutoBT followed by delayed implant placements from Nov. 2008 to Aug. 2010 were evaluated. A total of fifteen implants were placed. The primary and secondary stability of the placed implants were an average of 58 ISQ and 77.9 ISQ, respectively. The average amount of crestal bone loss around the implant was 0.05 mm during an average of 22.5 months (from 12 to 34 months) of functional loading. Newly formed tissues were evident from the 3-month specimen. Within the limitations of this case, autogenous tooth bone graft material can be a favorable bone substitute for extraction socket graft due to its good bone remodeling and osteoconductivity. PMID:25551013

Tea stains-inspired initiator primer for surface grafting of antifouling and antimicrobial polymer brush coatings.

PubMed

Pranantyo, Dicky; Xu, Li Qun; Neoh, Koon-Gee; Kang, En-Tang; Ng, Ying Xian; Teo, Serena Lay-Ming

2015-03-09

Inspired by tea stains, plant polyphenolic tannic acid (TA) was beneficially employed as the primer anchor for functional polymer brushes. The brominated TA (TABr) initiator primer was synthesized by partial modification of TA with alkyl bromide functionalities. TABr with trihydroxyphenyl moieties can readily anchor on a wide range of substrates, including metal, metal oxide, polymer, glass, and silicon. Concomitantly, the alkyl bromide terminals serve as initiation sites for atom transfer radical polymerization (ATRP). Cationic [2-(methacryloyloxy)ethyl]trimethylammonium chloride (META) and zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) and N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine (SBMA) were graft-polymerized from the TABr-anchored stainless steel (SS) surface. The cationic polymer brushes on the modified surfaces are bactericidal, while the zwitterionic coatings exhibit resistance against bacterial adhesion. In addition, microalgal attachment (microfouling) and barnacle cyprid settlement (macrofouling) on the functional polymer-grafted surfaces were significantly reduced, in comparison to the pristine SS surface. Thus, the bifunctional TABr initiator primer provides a unique surface anchor for the preparation of functional polymer brushes for inhibiting both microfouling and macrofouling.

Modeling of Interfacial Modification Effects on Thermal Conductivity of Carbon Nanotube Composites

NASA Technical Reports Server (NTRS)

Clancy, Thomas C.; Gates, Thomas S.

2006-01-01

The effect of functionalization of carbon nanotubes on the thermal conductivity of nanocomposites has been studied using a multi-scale modeling approach. These results predict that grafting linear hydrocarbon chains to the surface of a single wall carbon nanotube with covalent chemical bonds should result in a significant increase in the thermal conductivity of these nanocomposites. This is due to the decrease in the interfacial thermal (Kapitza) resistance between the single wall carbon nanotube and the surrounding polymer matrix upon chemical functionalization. The nanocomposites studied here consist of single wall carbon nanotubes in a bulk poly(ethylene vinyl acetate) matrix. The nanotubes are functionalized by end-grafting linear hydrocarbon chains of varying length to the surface of the nanotube. The effect which this functionalization has on the interfacial thermal resistance is studied by molecular dynamics simulation. Interfacial thermal resistance values are calculated for a range of chemical grafting densities and with several chain lengths. These results are subsequently used in an analytical model to predict the resulting effect on the bulk thermal conductivity of the nanocomposite.

Silicon tetrachloride plasma induced grafting for starch-based composites

NASA Astrophysics Data System (ADS)

Ma, Yonghui C.

Non-modified virgin starch is seldom used directly in industrial applications. Instead, it is often physically and/or chemically modified to achieve certain enhanced properties. For many of the non-food applications, these modifications involve changing its hydrophilicity to create hydrophobic starch. In this study, the hydrophobic starch was produced through silicon tetrachloride (SiCl4) plasma induced graft polymerization, so that it could be used as a renewable and biodegradable component of, or substitute for, the petrochemical-based plastics. It was suggested that this starch graft-copolymer might be used as reinforcing components in silicone-rubber materials for starch-based composites. To make this starch graft-copolymer, the ethyl ether-extracted starch powders were surface functionalized by SiCl4 plasma using a 13.56 MHz radio frequency rotating plasma reactor and subsequently stabilized by either ethylene diamine or dichlorodimethylsilane (DCDMS). The functionalized starch was then graft-polymerized with DCDMS to form polydimethylsiloxane (PDMS) layers around the starch granules. The presence of this PDMS layer was demonstrated by electron spectroscopy for chemical analysis (ESCA/XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), gas chromatography-mass spectroscopy (GC-MS), thermo gravimetry/differential thermal analysis (TG/DTA), and other analyses. It was shown that the surface morphology, thermal properties, swelling characteristic, and hydrophilicity of starch were all changed due to the existence of this protective hydrophobic PDMS layer. Several different procedures to carry out the functionalization and graft polymerization steps were evaluated to improve the effectiveness of the reactions and to prevent the samples from being hydrolyzed by the grafting byproduct HCl. Actinometry, GC-MS, and residual gas analyzer (RGA) were used to investigate the mechanisms of the SiCl4 discharge and to optimize the plasma modification. These plasma diagnostic results showed that, to achieve better plasma modification, higher plasma power and lower SiCl4 vapor pressure would be needed; however, it was found that the efficiency of the modification peaked at a certain point of plasma treatment time (˜10 minutes) and there was not much subsequent improvement with prolonged plasma treatment.

Allogeneic versus autologous derived cell sources for use in engineered bone-ligament-bone grafts in sheep anterior cruciate ligament repair.

PubMed

Mahalingam, Vasudevan D; Behbahani-Nejad, Nilofar; Horine, Storm V; Olsen, Tyler J; Smietana, Michael J; Wojtys, Edward M; Wellik, Deneen M; Arruda, Ellen M; Larkin, Lisa M

2015-03-01

The use of autografts versus allografts for anterior cruciate ligament (ACL) reconstruction is controversial. The current popular options for ACL reconstruction are patellar tendon or hamstring autografts, yet advances in allograft technologies have made allogeneic grafts a favorable option for repair tissue. Despite this, the mismatched biomechanical properties and risk of osteoarthritis resulting from the current graft technologies have prompted the investigation of new tissue sources for ACL reconstruction. Previous work by our lab has demonstrated that tissue-engineered bone-ligament-bone (BLB) constructs generated from an allogeneic cell source develop structural and functional properties similar to those of native ACL and vascular and neural structures that exceed those of autologous patellar tendon grafts. In this study, we investigated the effectiveness of our tissue-engineered ligament constructs fabricated from autologous versus allogeneic cell sources. Our preliminary results demonstrate that 6 months postimplantation, our tissue-engineered auto- and allogeneic BLB grafts show similar histological and mechanical outcomes indicating that the autologous grafts are a viable option for ACL reconstruction. These data indicate that our tissue-engineered autologous ligament graft could be used in clinical situations where immune rejection and disease transmission may preclude allograft use.

Islet graft survival and function: concomitant culture and transplantation with vascular endothelial cells in diabetic rats.

PubMed

Pan, Xiaoming; Xue, Wujun; Li, Yang; Feng, Xinshun; Tian, Xiaohui; Ding, Chenguang

2011-12-15

Human islet transplantation is a great potential therapy for type I diabetes. To investigate islet graft survival and function, we recently showed the improved effects after co-culture and co-transplantation with vascular endothelial cells (ECs) in diabetic rats. ECs were isolated, and the viability of isolated islets was assessed in two groups (standard culture group and co-culture group with ECs). Then streptozotocin-induced diabetic rats were divided into four groups before islet transplantation as follows: group A with infusion of islet grafts; group B with combined vascular ECs and islet grafts; groups C and D as controls with single ECs infusion and phosphate-buffered saline injection, respectively. Blood glucose and insulin concentrations were measured daily. Expression of vascular endothelial growth factor was investigated by immunohistochemical staining. The mean microvascular density was also calculated. More than 90% of acridine orange-propidium iodide staining positive islets demonstrated normal morphology while co-cultured with ECs for 7 days. Compared with standard control, insulin release assays showed a significantly higher simulation index in co-culture group except for the first day (P<0.05). After transplantation, there was a significant difference in concentrations of blood glucose and insulin among these groups after 3 days (P<0.05). The mean microvascular density in co-culture group was significantly higher than that in single islet group (P=0.04). Co-culture with ECs in vitro could improve the survival and function of isolated rat islet, and co-transplantation of islets with ECs could effectively prolong the islet graft survival in diabetic rats.

Return to sports and functional results after revision anterior cruciate ligament reconstruction by fascia lata autograft.

PubMed

Mirouse, G; Rousseau, R; Casabianca, L; Ettori, M A; Granger, B; Pascal-Moussellard, H; Khiami, F

2016-11-01

The surgical revision rate following anterior cruciate ligament (ACL) surgery is 3% at 2 years and 4% at 5 years. Revision ACL surgery raises the question of the type of graft to be used. The present study assessed return to sports and functional results after revision ACL reconstruction by fascia lata graft. The hypothesis was that fascia lata provides a reliable graft in revision ACL surgery. A single-center retrospective continuous study included 30 sports players with a mean age of 26.8±8 years undergoing surgical revision for iterative ACL tear between 2004 and 2013. Multi-ligament lesions were excluded. Type and level of sports activity were assessed preoperatively, after primary surgery and at end of follow-up. Clinical assessment used subjective IKDC, Lysholm and KOOS scores. At a mean 4.6±1.6 years' follow-up, all patients had resumed sport activity, but only 12 with the same sport at the same level. Median subjective IKDC score increased from 57 [54.3; 58.5] preoperatively to 82 [68.3; 90] at last follow-up, and Lysholm score from 46 [42.3; 51] to 90.5 [80.8; 96.8]; KOOS score at last follow-up was 94.7 [83; 100]. Functional results in revision ACL reconstruction by fascia lata graft were satisfactory, with similar return-to-sports rates as with other techniques. Fascia lata provides a reliable graft in revision ACL surgery. IV, retrospective study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Periodontal considerations for esthetics: edentulous ridge augmentation.

PubMed

Rosenberg, E S; Cutler, S A

1993-01-01

Edentulous ridge augmentation is a plastic surgical technique that is performed to improve patient esthetics when unsightly, deformed ridges exist. This article describes the etiology of ridge deformities and the many procedures that can be executed to achieve an esthetic, functional result. Historically, soft-tissue mucogingival techniques were described to augment collapsed ridges. Pedicle grafts, free soft-tissue grafts, and subepithelial connective tissue grafts are predictable forms of therapy. More recently, ridge augmentation techniques were developed that regenerate the lost periodontium. These include allografts, bioglasses, guided tissue regenerative procedures, and tissue expansion.

Clinical and Biochemical Characteristics of Brain-Dead Donors as Predictors of Early- and Long-Term Renal Function After Transplant.

PubMed

Kwiatkowska, Ewa; Domański, Leszek; Bober, Joanna; Safranow, Krzysztof; Pawlik, Andrzej; Ciechanowski, Kazimierz; Wiśniewska, Magda; Kędzierska, Karolina

2017-08-01

Organs from brain-dead donors are the main source of allografts for transplant. Comparisons between living-donor and brain-dead donor kidneys show that the latter are more likely to demonstrate delayed graft function and lower long-term survival. This study aimed to assess the effects of various clinical and biochemical factors of donors on early- and long-term renal function after transplant. We analyzed data from kidney recipients treated between 2006 and 2008 who received organs from brain-dead donors. Data from 54 donors and 89 recipients were analyzed. No relation was observed between donor sodium concentration and the presence of delayed graft function. Donor height was positively correlated with creatinine clearance in recipients in the 1 to 3 months after renal transplant. Donor diastolic blood pressure was negatively correlated with estimated glomerular filtration rate throughout the observation period. Donor age was negatively correlated with the allograft recipient's estimated glomerular filtration rate throughout 4 years of observation. Donor estimated glomerular filtration rate was positively correlated with that of the recipient throughout 3 years of observation. The results of this study indicate that various factors associated with allograft donors may influence graft function.

Chemical Messengers of Inflammation.

DTIC Science & Technology

1981-04-29

the skin grafts is 10 to 12 days. We can prolong this up to 15 days with the bacterial product at the moment. We are in the process of making more of...lymphocyte function both in vitro and in vivo. Preliminary studies have indicated that the polyamine, when dimerized, will, in fact, delay skin graft rejection

Revolutionizing orthopaedic biomaterials: The potential of biodegradable and bioresorbable magnesium-based materials for functional tissue engineering

PubMed Central

Farraro, Kathryn F.; Kim, Kwang E.; Woo, Savio L-Y.; Flowers, Jonquil R.; McCullough, Matthew B.

2014-01-01

In recent years, there has been a surge of interest in magnesium (Mg) and its alloys as biomaterials for orthopaedic applications, as they possess desirable mechanical properties, good biocompatibility, and biodegradability. Also shown to be osteoinductive, Mg-based materials could be particularly advantageous in functional tissue engineering to improve healing and serve as scaffolds for delivery of drugs, cells, and cytokines. In this paper, we will present two examples of Mg-based orthopaedic devices: an interference screw to accelerate ACL graft healing and a ring to aid in the healing of an injured ACL. In vitro tests using a robotic/UFS testing system showed that both devices could restore function of the goat stifle joint. Under a 67-N anterior tibial load, both the ACL graft fixed with the Mg-based interference screw and the Mg-based ring-repaired ACL could restore anterior tibial translation (ATT) to within 2 mm and 5 mm, respectively, of the intact joint at 301, 601, and 901 of flexion. In-situ forces in the replacement graft and Mg-based ring-repaired ACL were also similar to those of the intact ACL. Further, early in vivo data using the Mg-based interference screw showed that after 12 weeks, it was non-toxic and the joint stability and graft function reached similar levels as published data. Following these positive results, we will move forward in incorporating bioactive molecules and ECM bioscaffolds to these Mg-based biomaterials to test their potential for functional tissue engineering of musculoskeletal and other tissues. PMID:24373510

Revolutionizing orthopaedic biomaterials: The potential of biodegradable and bioresorbable magnesium-based materials for functional tissue engineering.

PubMed

Farraro, Kathryn F; Kim, Kwang E; Woo, Savio L-Y; Flowers, Jonquil R; McCullough, Matthew B

2014-06-27

In recent years, there has been a surge of interest in magnesium (Mg) and its alloys as biomaterials for orthopaedic applications, as they possess desirable mechanical properties, good biocompatibility, and biodegradability. Also shown to be osteoinductive, Mg-based materials could be particularly advantageous in functional tissue engineering to improve healing and serve as scaffolds for delivery of drugs, cells, and cytokines. In this paper, we will present two examples of Mg-based orthopaedic devices: an interference screw to accelerate ACL graft healing and a ring to aid in the healing of an injured ACL. In vitro tests using a robotic/UFS testing system showed that both devices could restore function of the goat stifle joint. Under a 67-N anterior tibial load, both the ACL graft fixed with the Mg-based interference screw and the Mg-based ring-repaired ACL could restore anterior tibial translation (ATT) to within 2mm and 5mm, respectively, of the intact joint at 30°, 60°, and 90° of flexion. In-situ forces in the replacement graft and Mg-based ring-repaired ACL were also similar to those of the intact ACL. Further, early in vivo data using the Mg-based interference screw showed that after 12 weeks, it was non-toxic and the joint stability and graft function reached similar levels as published data. Following these positive results, we will move forward in incorporating bioactive molecules and ECM bioscaffolds to these Mg-based biomaterials to test their potential for functional tissue engineering of musculoskeletal and other tissues. © 2013 Published by Elsevier Ltd.

Cryopreservation, Culture, and Transplantation of Human Fetal Mesencephalic Tissue into Monkeys

NASA Astrophysics Data System (ADS)

Redmond, D. E.; Naftolin, F.; Collier, T. J.; Leranth, C.; Robbins, R. J.; Sladek, C. D.; Roth, R. H.; Sladek, J. R.

1988-11-01

Studies in animals suggest that fetal neural grafts might restore lost neurological function in Parkinson's disease. In monkeys, such grafts survive for many months and reverse signs of parkinsonism, without attendant graft rejection. The successful and reliable application of a similar transplantation procedure to human patients, however, will require neural tissue obtained from human fetal cadavers, with demonstrated cellular identity, viability, and biological safety. In this report, human fetal neural tissue was successfully grafted into the brains of monkeys. Neural tissue was collected from human fetal cadavers after 9 to 12 weeks of gestation and cryopreserved in liquid nitrogen. Viability after up to 2 months of storage was demonstrated by cell culture and by transplantation into monkeys. Cryopreservation and storage of human fetal neural tissue would allow formation of a tissue bank. The stored cells could then be specifically tested to assure their cellular identity, viability, and bacteriological and virological safety before clinical use. The capacity to collect and maintain viable human fetal neural tissue would also facilitate research efforts to understand the development and function of the human brain and provide opportunities to study neurological diseases.

[Hypertrophic adipose tissue transplantation secondary to a lipopenisculpture].

PubMed

Moullot, P; Nguyen, P-S; Philandrianos, C; Casanova, D

2014-10-01

Reconstruction of the penile skin requires a functional and esthetically perfect result, combining a high degree of skin elasticity to allow regular erections and a satisfactory cosmetic appearance. Demand for cosmetic surgery penile augmentation continues to increase for several years. The surgical technique most commonly used is now widening and lengthening lipopenisculpture (LPS), combining an adipocyte graft to a section of the suspensory ligament of the penis. A patient who underwent LPS presented several years after a major hypertrophy of the adipocyte graft, making it impossible to have sexual activities, imposing to perform liposuction. This liposuction was being complicated by necrosis of the penile skin. Reconstruction was required and consisted of an unexpanded thin skin graft associated with artificial dermis. Through technical adaptation of the skin graft on the erect penis, the use of artificial dermis and external stabilization by negative pressure therapy, reconstruction of the penile skin provides excellent aesthetic and functional results. Finally, it is rarely reported in the literature complications of lipofilling like alteration of the aesthetic result after weight gain. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Use of fibular bone graft and cancellous screw fixation in the management of neglected femur neck fractures in young patients.

PubMed

Khani, Ghulam Mustafa Kaim; Hafeez, Kamran; Bux, Muhammad; Rasheed, Nusrat; Ahmed, Naveed; Anjum, M Perwez

2017-01-01

To present the clinical outcome of patients with neglected femur neck fracture treated with fibular bone graft. During May 2010-February 2013, 15 patients younger than 35 years of age with neglected fracture neck of femur were managed with non-vascularized fibular graft and cannulated screws. Fractures were classified according to Sandhu Classification. Hip function was assessed using Harris hip score. Fifteen patients with mean age of 28.67 years were managed. Mean period of delay from injury to presentation was 3.07 months. Mean follow-up was 18.5 months. Union was achieved in 13 cases. 2 patients developed nonunion with progression of avascular necrosis (AVN). Patients with healed fracture did not show radiological signs of AVN till the past follow-up. Functional status was evaluated at 6 months according to Harris hip score and was poor in 2 patients, fair in 2 patients, good in 6 patients, and excellent in 5 patients. Fibular graft along with two cancellous screws proved to be an effective technique in our cases with neglected femur neck fractures.

Application of stem cells for cardiovascular grafts tissue engineering.

PubMed

Wu, Kaihong; Liu, Ying Long; Cui, Bin; Han, Zhongchao

2006-06-01

Congenital and acquired heart diseases are leading causes of morbidity and mortality world-wide. Currently, the synthetic materials or bioprosthetic replacement devices for cardiovascular surgery are imperfect and subject patients to one or more ongoing risks including thrombosis, limited durability and need for reoperations due to lack of growth in children and young adults. Suitable replacement grafts should have appropriate characteristics, including resistance to infection, low immunogenicity, good biocompatability and thromboresistance, with appropriate mechanical and physiological properties. Tissue engineering is a new scientific field aiming at fabrication of living, autologous grafts having structure or function properties that can be used to restore, maintain or improve tissue function. The use of autologous stem cells in cardiovascular tissue engineering is quite promising due to their capacity of self-renewal, high proliferation, and differentiation into specialized progeny. Progress has been made in engineering the various components of the cardiovascular system, including myocardial constructs, heart valves, and vascular patches or conduits with autologous stem cells. This paper will review the current achievements in stem cell-based cardiovascular grafts tissue engineering, with an emphasis on its clinical or possible clinical use in cardiovascular surgery.

Ex-vivo machine perfusion for kidney preservation.

PubMed

Hamar, Matyas; Selzner, Markus

2018-06-01

Machine perfusion is a novel strategy to decrease preservation injury, improve graft assessment, and increase organ acceptance for transplantation. This review summarizes the current advances in ex-vivo machine-based kidney preservation technologies over the last year. Ex-vivo perfusion technologies, such as hypothermic and normothermic machine perfusion and controlled oxygenated rewarming, have gained high interest in the field of organ preservation. Keeping kidney grafts functionally and metabolically active during the preservation period offers a unique chance for viability assessment, reconditioning, and organ repair. Normothermic ex-vivo kidney perfusion has been recently translated into clinical practice. Preclinical results suggest that prolonged warm perfusion appears superior than a brief end-ischemic reconditioning in terms of renal function and injury. An established standardized protocol for continuous warm perfusion is still not available for human grafts. Ex-vivo machine perfusion represents a superior organ preservation method over static cold storage. There is still an urgent need for the optimization of the perfusion fluid and machine technology and to identify the optimal indication in kidney transplantation. Recent research is focusing on graft assessment and therapeutic strategies.

3D-Printing Composite Polycaprolactone-Decellularized Bone Matrix Scaffolds for Bone Tissue Engineering Applications.

PubMed

Rindone, Alexandra N; Nyberg, Ethan; Grayson, Warren L

2017-05-11

Millions of patients worldwide require bone grafts for treatment of large, critically sized bone defects from conditions such as trauma, cancer, and congenital defects. Tissue engineered (TE) bone grafts have the potential to provide a more effective treatment than current bone grafts since they would restore fully functional bone tissue in large defects. Most bone TE approaches involve a combination of stem cells with porous, biodegradable scaffolds that provide mechanical support and degrade gradually as bone tissue is regenerated by stem cells. 3D-printing is a key technique in bone TE that can be used to fabricate functionalized scaffolds with patient-specific geometry. Using 3D-printing, composite polycaprolactone (PCL) and decellularized bone matrix (DCB) scaffolds can be produced to have the desired mechanical properties, geometry, and osteoinductivity needed for a TE bone graft. This book chapter will describe the protocols for fabricating and characterizing 3D-printed PCL:DCB scaffolds. Moreover, procedures for culturing adipose-derived stem cells (ASCs) in these scaffolds in vitro will be described to demonstrate the osteoinductivity of the scaffolds.

Brain death and marginal grafts in liver transplantation.

PubMed

Jiménez-Castro, M B; Gracia-Sancho, J; Peralta, C

2015-06-04

It is well known that most organs for transplantation are currently procured from brain-dead donors; however, the presence of brain death is an important risk factor in liver transplantation. In addition, one of the mechanisms to avoid the shortage of liver grafts for transplant is the use of marginal livers, which may show higher risk of primary non-function or initial poor function. To our knowledge, very few reviews have focused in the field of liver transplantation using brain-dead donors; moreover, reviews that focused on both brain death and marginal grafts in liver transplantation, both being key risk factors in clinical practice, have not been published elsewhere. The present review aims to describe the recent findings and the state-of-the-art knowledge regarding the pathophysiological changes occurring during brain death, their effects on marginal liver grafts and summarize the more controversial topics of this pathology. We also review the therapeutic strategies designed to date to reduce the detrimental effects of brain death in both marginal and optimal livers, attempting to explain why such strategies have not solved the clinical problem of liver transplantation.

Grafting of Chitosan and Chitosantrimethoxylsilylpropyl Methacrylate on Single Walled Carbon Nanotubes-Synthesis and Characterization

PubMed Central

Carson, Laura; Kelly-Brown, Cordella; Stewart, Melisa; Oki, Aderemi; Regisford, Gloria; Stone, Julia; Traisawatwong, Pasakorn; Durand-Rougely, Clarissa; Luo, Zhiping

2011-01-01

Acid functionalized single walled carbon nanotubes (CNTs) were grafted to chitosan by first reacting the oxidized CNTs with thionyl chloride to form acyl-chlorinated CNTs. This product was subsequently dispersed in chitosan and covalently grafted to form CNT-chitosan. CNT-chitosan was further grafted onto 3-trimethoxysilylpropyl methacrylate by free radical polymerization conditions, to yield CNT-g-chitosan-g-3-trimethoxysilylpropyl methacrylate (TMSPM), hereafter referred to as CNT-chitosan-3-TMSPM. These composites were characterized by Fourier Transform Infrared Resonance Spectroscopy (FTIR), carbon-13 nuclear magnetic resonance (13C NMR), Thermogravimetric Analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composite showed improved thermal stability and could be of great potential use in bone tissue engineering. PMID:21765959

Hepatic encephalopathy in a liver transplant recipient with stable liver function.

PubMed

Arab, Juan Pablo; Meneses, Luis; Pérez, Rosa M; Arrese, Marco; Benítez, Carlos

2013-04-01

Postshunt hepatic encephalopathy after liver transplantation (LT) is an infrequent condition and is commonly associated with portal occlusion or stenosis and the presence of a patent portosystemic shunt. Portal vein stenosis (PVS) or thrombosis (PVT) are uncommon complications after LT. The overall frequency of both complications is reported to be less than 3%. When PVS or PVT develop early after LT, the occlusion of the portal vein can have catastrophic consequences to the graft including acute liver failure and graft loss. Late PVT/PVS are asymptomatic in approximately 50% of the cases and mainly diagnosed by a routine ultrasound. Symptomatic postshunt hepatic encephalopathy (HE) is a very infrequent condition after LT that has been scarcely reported in the literature. We present here the case of a liver recipient with normal graft function who presented with hepatic encephalopathy 3 months after LT with stable liver function but a severe portal stenosis and the presence of a spontaneous portosystemic shunt whose successful endovascular treatment was followed by the complete resolution of the HE.

Synthesis and characterization of bifunctional surfaces with tunable functional group pairs

NASA Astrophysics Data System (ADS)

Galloway, John M.; Kung, Mayfair; Kung, Harold H.

2016-06-01

Grafting of pairs of functional groups onto a silica surface was demonstrated by tethering both terminals of an organochlorosilane precursor molecule, Cl2(CH3)Si(CH2)4(CO)(OSi(i-Pr)2)(CH2)2Si(CH3)Cl2, that possess a cleavable silyl ester bond, onto a silica surface. Hydrolytic cleavage of the silyl ester bond of the grafted molecule resulted in the generation of organized pairs of carboxylic acid and organosilanol groups. This organosilanol moiety was easily transformed into other functional groups through condensation reactions to form, together with the neighboring acid group, pairs such as carboxylic acid/secondary amine, carboxylic acid/pyridine, and carboxylic acid/phosphine. In the case of carboxylic acid/amine pairing, there was evidence of the formation of amide. A sample grafted with amine-carboxylic acid pairs was three times more active (per free amine) than a sample without such pairs for the nitroaldol condensation of 4-nitrobenzaldehyde and nitromethane.

Solid phase graft copolymerization of acrylic monomers onto thermoplastics and their use as blend compatibilizers

NASA Astrophysics Data System (ADS)

Subramanian, Srinivas

This research work is an extension of some of the earlier work done on the development of solid phase grafting technique to graft various monomers onto polymers as well as postulation of the usefulness of the graft copolymers thus synthesized. Polystyrene grafted with acrylic acid, previously developed in bench scale, was synthesized in pilot-plant scale batches. Process parameter studies on the grafting of acrylic acid onto polypropylene and developmental studies on the grafting of maleic anhydride onto polystyrene were also done. Polymers grafted with polar molecules such as maleic anhydride and acrylic acid have been used to compatibilize immiscible blends of polar and non-polar polymers. On the same note, the applicability of the solid phase graft copolymers as blend compatibilizers were investigated and their performance was compared to commercially available compatibilizers. Solid phase graft copolymerization process is a technique to synthesize graft copolymers. Some of its salient features are use of minimal solvent to conduct the reaction and easy equipment modification. It is a low pressure and low temperature process. This technique provides a viable alternative to the environmentally hazardous, and time consuming conventional process currently in use. Hence, development of this technique could be beneficial not only to the plastics industry, but also to mankind. Also, this technique provides a low-cost and extremely easy method to develop graft copolymers such as acrylic acid functionalized polymers that are rapidly gaining popularity as blend compatibilizers and polymer reinforcing agents. A study that proves the potential of these solid phase graft copolymers as good blend compatibilizers for industrially important immiscible polymers will develop interest in the industries about this grafting process. The free radical solid phase graft copolymerization process was carried in a modified Brabender-type mixer fitted with specially designed blades to promote efficient mixing of the polymer, initiator, monomer, and solvent. The grafting was qualitatively confirmed by means of a FTIR and quantitatively using titration. The polymer blends were synthesized in a single screw extruder. Rheological, morphological, thermal, mechanical, and molecular weight studies were done on these blends. The graft copolymers produced in larger batches had the same amount of graft content as those produced in smaller batches. This small success is a positive step towards the goal of commercializing this process. Grafting of acrylic acid onto polypropylene gave graft levels of 4 weight percent. However, the attempt to graft maleic anhydride onto polystyrene was not successful. The solid phase graft copolymers were successfully able to compatibilize the polymer blend systems studied (PS/PMMA, PS/nylon 6,6, PS/nylon 6, and PP/nylon 6). The properties of the blends compatibilized using the solid phase graft copolymers were comparable to and in some instances, better than those of the blends compatibilized with commercially available graft copolymers. The successful scale-up of the process, development of new graft copolymers and ability of copolymers to compatibilize blends augurs well for the solid phase grafting process.

Amelioration of motor/sensory dysfunction and spasticity in a rat model of acute lumbar spinal cord injury by human neural stem cell transplantation

PubMed Central

2013-01-01

Introduction Intraspinal grafting of human neural stem cells represents a promising approach to promote recovery of function after spinal trauma. Such a treatment may serve to: I) provide trophic support to improve survival of host neurons; II) improve the structural integrity of the spinal parenchyma by reducing syringomyelia and scarring in trauma-injured regions; and III) provide neuronal populations to potentially form relays with host axons, segmental interneurons, and/or α-motoneurons. Here we characterized the effect of intraspinal grafting of clinical grade human fetal spinal cord-derived neural stem cells (HSSC) on the recovery of neurological function in a rat model of acute lumbar (L3) compression injury. Methods Three-month-old female Sprague–Dawley rats received L3 spinal compression injury. Three days post-injury, animals were randomized and received intraspinal injections of either HSSC, media-only, or no injections. All animals were immunosuppressed with tacrolimus, mycophenolate mofetil, and methylprednisolone acetate from the day of cell grafting and survived for eight weeks. Motor and sensory dysfunction were periodically assessed using open field locomotion scoring, thermal/tactile pain/escape thresholds and myogenic motor evoked potentials. The presence of spasticity was measured by gastrocnemius muscle resistance and electromyography response during computer-controlled ankle rotation. At the end-point, gait (CatWalk), ladder climbing, and single frame analyses were also assessed. Syrinx size, spinal cord dimensions, and extent of scarring were measured by magnetic resonance imaging. Differentiation and integration of grafted cells in the host tissue were validated with immunofluorescence staining using human-specific antibodies. Results Intraspinal grafting of HSSC led to a progressive and significant improvement in lower extremity paw placement, amelioration of spasticity, and normalization in thermal and tactile pain/escape thresholds at eight weeks post-grafting. No significant differences were detected in other CatWalk parameters, motor evoked potentials, open field locomotor (Basso, Beattie, and Bresnahan locomotion score (BBB)) score or ladder climbing test. Magnetic resonance imaging volume reconstruction and immunofluorescence analysis of grafted cell survival showed near complete injury-cavity-filling by grafted cells and development of putative GABA-ergic synapses between grafted and host neurons. Conclusions Peri-acute intraspinal grafting of HSSC can represent an effective therapy which ameliorates motor and sensory deficits after traumatic spinal cord injury. PMID:23710605

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

PubMed

Kaur, Inderjeet; Kumar, Raj; Sharma, Neelam

2010-10-13

Functionalization of rayon fibre has been carried out by grafting acrylic acid (AAC) both by a chemical method using a Ce(4+)-HNO(3) redox initiator and by a mutual irradiation (γ-rays) method. The reaction conditions affecting the grafting percentage have been optimized for both methods, and the results are compared. The maximum percentage of grafting (50%) by the chemical method was obtained utilizing 18.24 × 10(-3) moles/L of ceric ammonium nitrate (CAN), 39.68 × 10(-2) moles/L of HNO(3), and 104.08 × 10(-2) moles/L of AAc in 20 mL of water at 45°C for 120 min. For the radiation method, the maximum grafting percentage (60%) was higher, and the product was obtained under milder reaction conditions using a lower concentration of AAc (69.38 × 10(-2) moles/L) in 10 mL of water at an optimum total dose of 0.932 kGy. Swelling studies showed higher swelling for the grafted rayon fibre in water (854.54%) as compared to the pristine fibre (407%), while dye uptake studies revealed poor uptake of the dye (crystal violet) by the grafted fibre in comparison with the pristine fibre. The graft copolymers were characterized by IR, TGA, and scanning electron micrographic methods. Grafted fibre, prepared by the radiation-induced method, showed better thermal behaviour. Comparison of the two methods revealed that the radiation method of grafting of acrylic acid onto rayon fibre is a better method of grafting in comparison with the chemical method. Copyright © 2010 Elsevier Ltd. All rights reserved.

Impact of transplant nephrectomy on peak PRA levels and outcome after kidney re-transplantation

PubMed Central

Tittelbach-Helmrich, Dietlind; Pisarski, Przemyslaw; Offermann, Gerd; Geyer, Marcel; Thomusch, Oliver; Hopt, Ulrich Theodor; Drognitz, Oliver

2014-01-01

AIM: To determine the impact of transplant nephrectomy on peak panel reactive antibody (PRA) levels, patient and graft survival in kidney re-transplants. METHODS: From 1969 to 2006, a total of 609 kidney re-transplantations were performed at the University of Freiburg and the Campus Benjamin Franklin of the University of Berlin. Patients with PRA levels above (5%) before first kidney transplantation were excluded from further analysis (n = 304). Patients with graft nephrectomy (n = 245, NE+) were retrospectively compared to 60 kidney re-transplants without prior graft nephrectomy (NE-). RESULTS: Peak PRA levels between the first and the second transplantation were higher in patients undergoing graft nephrectomy (P = 0.098), whereas the last PRA levels before the second kidney transplantation did not differ between the groups. Age adjusted survival for the second kidney graft, censored for death with functioning graft, were comparable in both groups. Waiting time between first and second transplantation did not influence the graft survival significantly in the group that underwent nephrectomy. In contrast, patients without nephrectomy experienced better graft survival rates when re-transplantation was performed within one year after graft loss (P = 0.033). Age adjusted patient survival rates at 1 and 5 years were 94.1% and 86.3% vs 83.1% and 75.4% group NE+ and NE-, respectively (P < 0.01). CONCLUSION: Transplant nephrectomy leads to a temporary increase in PRA levels that normalize before kidney re-transplantation. In patients without nephrectomy of a non-viable kidney graft timing of re-transplantation significantly influences graft survival after a second transplantation. Most importantly, transplant nephrectomy is associated with a significantly longer patient survival. PMID:25032103

International Approaches in Human Rights Education

NASA Astrophysics Data System (ADS)

Lohrenscheit, Claudia

2002-07-01

This paper was presented at a working group on Human Rights Education (HRE), organised by Volker Lenhart and Christel Adick, as part of the biennial conference of the German Society for Educational Research (DGfE), held in 2000 in Göttingen. In the spirit of the United Nations Decade for Human Rights Education (1995-2004) it contributes to the global discourse about HRE by summarising its foundations in international declarations and conventions, by discussing some examples for diverse approaches and conceptions of HRE and, finally by introducing some major obstacles or problems. The paper is part of the author's PhD project in the field of HRE and presents only an interim résumé of her recent work.

Glenoid bone grafting in primary reverse total shoulder arthroplasty.

PubMed

Ernstbrunner, Lukas; Werthel, Jean-David; Wagner, Eric; Hatta, Taku; Sperling, John W; Cofield, Robert H

2017-08-01

Severe glenoid bone loss remains a challenge in patients requiring shoulder arthroplasty and may necessitate glenoid bone grafting. The purpose of this study was to determine results, complications, and rates of failure of glenoid bone grafting in primary reverse shoulder arthroplasty. Forty-one shoulders that underwent primary reverse arthroplasty between 2006 and 2013 with a minimum follow-up of 2 years (mean, 2.8 years; range, 2-6 years) were reviewed. Thirty-four (83%) received corticocancellous grafts and 7 (17%) structural grafts. Active range of motion and pain levels were significantly improved (P < .001), with mean American Shoulder and Elbow Surgeons score of 77, Simple Shoulder Test score of 9, and patient satisfaction of 93% at the most recent follow-up. Preoperative severe glenoid erosion and increasing body mass index were significantly associated with worse American Shoulder and Elbow Surgeons scores (P = .04). On radiographic evaluation, 7 patients (18%) had grade 1 or grade 2 glenoid lucency. Glenoid bone graft incorporation was observed in 31 patients (78%). Twelve patients (30%) suffered from grade 1 or grade 2 scapular notching. All of the patients with structural grafts showed graft incorporation and no signs of glenoid lucency. Although glenoid lucency, glenoid graft resorption, and scapular notching were present at short-term to midterm follow-up, none of the patients needed revision surgery. Primary reverse shoulder arthroplasty with glenoid reconstruction using bone graft relieved pain and restored shoulder function and stability. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Establishing a Core Outcome Measure for Graft Health: a Standardized Outcomes in Nephrology - Kidney Transplantation (SONG-Tx) Consensus Workshop Report.

PubMed

Tong, Allison; Sautenet, Benedicte; Poggio, Emilio D; Lentine, Krista L; Oberbauer, Rainer; Mannon, Roslyn; Murphy, Barbara; Padilla, Benita; Chow, Kai Ming; Marson, Lorna; Chadban, Steve; Craig, Jonathan C; Ju, Angela; Manera, Karine E; Hanson, Camilla S; Josephson, Michelle A; Knoll, Greg

2018-02-22

Graft loss, a critically important outcome for transplant recipients, is variably defined and measured, and incompletely reported in trials. We convened a consensus workshop on establishing a core outcome measure for graft loss for all trials in kidney transplantation. Twenty-five kidney transplant recipients/caregivers and 33 health professionals from eight countries participated. Transcripts were analyzed thematically. Five themes were identified. "Graft loss as a continuum" conceptualizes graft loss as a process, but requiring an endpoint defined as a discrete event. In "defining an event with precision and accuracy," loss of graft function requiring chronic dialysis (minimum 90 days) provided an objective and practical definition; re-transplant would capture preemptive transplantation; relisting was readily measured but would overestimate graft loss; and allograft nephrectomy was redundant in being preceded by dialysis. However, the thresholds for renal replacement therapy varied. Conservative management was regarded as too ambiguous and complex to use routinely. "Distinguishing death-censored graft loss" would ensure clarity and meaningfulness in interpreting results. "Consistent reporting for decision-making" by specifying time points and metrics (ie time to event) was suggested. "Ease of ascertainment and data collection" of the outcome from registries could support use of registry data to efficiently extend follow-up of trial participants. A practical and meaningful core outcome measure for graft loss may be defined as chronic dialysis or re-transplant, and distinguished from loss due to death. Consistent reporting of graft loss using standardized metrics and time points may improve the contribution of trials to decision-making in kidney transplantation.

Islet and Stem Cell Encapsulation for Clinical Transplantation

PubMed Central

Krishnan, Rahul; Alexander, Michael; Robles, Lourdes; Foster 3rd, Clarence E.; Lakey, Jonathan R.T.

2014-01-01

Over the last decade, improvements in islet isolation techniques have made islet transplantation an option for a certain subset of patients with long-standing diabetes. Although islet transplants have shown improved graft function, adequate function beyond the second year has not yet been demonstrated, and patients still require immunosuppression to prevent rejection. Since allogeneic islet transplants have experienced some success, the next step is to improve graft function while eliminating the need for systemic immunosuppressive therapy. Biomaterial encapsulation offers a strategy to avoid the need for toxic immunosuppression while increasing the chances of graft function and survival. Encapsulation entails coating cells or tissue in a semipermeable biocompatible material that allows for the passage of nutrients, oxygen, and hormones while blocking immune cells and regulatory substances from recognizing and destroying the cell, thus avoiding the need for systemic immunosuppressive therapy. Despite advances in encapsulation technology, these developments have not yet been meaningfully translated into clinical islet transplantation, for which several factors are to blame, including graft hypoxia, host inflammatory response, fibrosis, improper choice of biomaterial type, lack of standard guidelines, and post-transplantation device failure. Several new approaches, such as the use of porcine islets, stem cells, development of prevascularized implants, islet nanocoating, and multilayer encapsulation, continue to generate intense scientific interest in this rapidly expanding field. This review provides a comprehensive update on islet and stem cell encapsulation as a treatment modality in type 1 diabetes, including a historical outlook as well as current and future research avenues. PMID:25148368

Embryonic kidney function in a chronic renal failure model in rodents.

PubMed

Fujimoto, Eisuke; Yamanaka, Shuichiro; Kurihara, Sho; Tajiri, Susumu; Izuhara, Luna; Katsuoka, Yuichi; Yokote, Shinya; Matsumoto, Kei; Kobayashi, Eiji; Okano, Hirotaka James; Chikaraishi, Tatsuya; Yokoo, Takashi

2017-08-01

Rapid advancements have been made in alternative treatments for renal diseases. Our goal for renal regeneration is to establish a kidney graft derived from human embryonic tissues. In this study, we investigated the effects of host renal failure on the structure and activity of transplanted embryonic kidney and bladder, and found that diuretics effectively induced urine production in the transplanted kidney. Uremic conditions were reproduced using a 5/6 renal infarction rat model. An embryonic kidney plus bladder (embryonic day 15) was isolated from a pregnant Lewis rat and transplanted into the para-aortic area of a 5/6 renal-infarcted Lewis rat. Following growth, the embryonic bladder was successfully anastomosed to the host ureter. We assessed graft function in terms of survival rates and found no differences between normal (n = 5) and renal failure (n = 8) groups (median survival: 70.5 vs 74.5 h; p = 0.331) in terms of survival, indicating that the grafts prolonged rat survival, even under renal failure conditions. Furosemide (n = 9) significantly increased urine volume compared with saline-treated controls (n = 7; p < 0.05), confirming that the grafts were functional. We also demonstrated the possibilities of an in vivo imaging system for determining the viability of transplanted embryonic kidney with bladder. The results of this study demonstrate that transplanted embryonic kidney and bladder can grow and function effectively, even under uremic conditions.

Urinary tract infection in renal transplant recipients: incidence, risk factors, and impact on graft function.

PubMed

Camargo, L F; Esteves, A B A; Ulisses, L R S; Rivelli, G G; Mazzali, M

2014-01-01

Urinary tract infection (UTI) is the most common infection posttransplant. However, the risk factors for and the impact of UTIs remain controversial. The aim of this study was to identify the incidence of posttransplant UTIs in a series of renal transplant recipients from deceased donors. Secondary objectives were to identify: (1) the most frequent infectious agents; (2) risk factors related to donor; (3) risk factors related to recipients; and (4) impact of UTI on graft function. This was a retrospective analysis of medical records from renal transplant patients from January to December 2010. Local ethics committee approved the protocol. The incidence of UTI in this series was 34.2%. Risk factors for UTI were older age, (independent of gender), biopsy-proven acute rejection episodes, and kidneys from deceased donors (United Network for Organ Sharing criteria). For female patients, the number of pretransplant pregnancies was an additional risk factor. Recurrent UTI was observed in 44% of patients from the UTI group. The most common infectious agents were Escherichia coli and Klebsiella pneumoniae, for both isolated and recurrent UTI. No difference in renal graft function or immunosuppressive therapy was observed between groups after the 1-year follow-up. In this series, older age, previous pregnancy, kidneys from expanded criteria donors, and biopsy-proven acute rejection episodes were risk factors for posttransplant UTI. Recurrence of UTI was observed in 44%, with no negative impact on graft function or survival. Copyright © 2014 Elsevier Inc. All rights reserved.

Controlling the burn and fueling the fire: defining the role for the alarmin interleukin-33 in alloimmunity.

PubMed

Liu, Quan; Turnquist, Heth R

2016-02-01

The purpose of this review is to provide a general update on recent developments in the immunobiology of IL-33 and IL-33-targeted immune cells. We also discuss emerging concepts regarding the potential role IL-33 appears to play in altering alloimmune responses mediating host-versus-graft and graft-versus-host alloresponses. Stromal cells and leukocytes display regulated expression of IL-33 and may actively or passively secrete this pleotropic cytokine. Type 2 innate lymphoid cells and a large proportion of tissue resident regulatory T cells (Treg) express membrane-bound suppressor of tumorigenicity 2 (ST2), the IL-33 receptor. Although Treg are appreciated suppressors of the inflammatory function of immune cells, both type 2 innate lymphoid cells and tissue resident Treg could play key roles in tissue repair and homeostasis. The functions of IL-33 in transplantation are poorly understood. However, like other disease models, the functions of IL-33 in alloimmunity appear to be quite pleiotropic. IL-33 is associated with immune regulation and graft protection in cardiac transplant settings. Yet, it is highly proinflammatory and stimulates lethal graft-versus-host disease through its capacity to stimulate type 1 immunity. Intensive studies on IL-33/ST2 signaling pathways and ST2 cell populations in solid organ and cell transplantation are warranted. A better understanding of this important pathway will provide promising therapeutic targets controlling pathogenic alloimmune responses, as well as potentially facilitating the function of regulatory and reparative immune cells posttransplantation.

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

PubMed

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

2012-01-01

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

Plasma-grafting polymerization on carbon fibers and its effect on their composite properties

NASA Astrophysics Data System (ADS)

Zhang, Huanxia; Li, Wei

2015-11-01

Interfacial adhesion between matrix and fibers plays a crucial role in controlling the performance of composites. Carbon fibers have the major constraint of chemical interness and hence have limited adhesion with the matrix. Surface treatment of fibers is the best solution to this problem. In this work, carbon fibers were activated by plasma and grafting polymerization. The grafting ratio of polymerization was obtained by acid-base titration. The chemical and physical changes induced by the treatments on carbon fiber surface was examined using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The interfacial adhesion of CF/EP (carbon fiber/epoxy) composites were analyzed by a single fiber composite (SFC) for filament fragmentation test. Experimental results show that the grafting rate was not only the function of the plasma-treat time but also the concentration of the grafting polymerization. The oxygen-containing groups (such as Csbnd O, Cdbnd O, and Osbnd Cdbnd O) and the interfacial shear strength (IFSS) of the plasma-grafting carbon fiber increased more significantly than the carbon fiber without plasma treatment grafted with MAH. This demonstrates that the surfaces of the carbon fiber samples are more active, hydrophilic, and rough after plasma-grafting treatments using a DBD operating in ambient argon mixture with oxygen. With DBD (dielectric barrier discharges) operating in ambient argon mixture with oxygen, the more active, hydrophilic, and rough surface was obtained by the plasma-grafting treatments.

Post-transplant HLA class II antibodies and high soluble CD30 levels are independently associated with poor kidney graft survival.

PubMed

Langan, L L; Park, L P; Hughes, T L; Irish, A; Luxton, G; Witt, C S; Christiansen, F T

2007-04-01

HLA-specific antibodies (HSA) and soluble CD30 (sCD30) were measured in 208 renal transplant recipients with functioning grafts at least 1 year after transplantation (median 8.2 years) to investigate the predictive value of HSA and sCD30 on subsequent graft outcome. HSA (class I and class II) were detected by both ELISA LAT-M and Luminex LabScreen assays. Data on graft outcome was collected with a median follow-up time of 3.5 years after antibody and sCD30 measurement. Recipients with post-transplant HLA class II antibodies had particularly poor graft outcome with a hazard ratio (HR) of 7.8 (p < 0.0001) when detected by ELISA, and a HR of 6.0 (p < 0.0001) when detected by Luminex. A high post-transplant sCD30 level >or=100 U/mL was associated with increased risk of subsequent graft failure (HR 2.7, p = 0.03). sCD30 and HSA had an independent and additive association with graft outcome. Recipients with HLA class II antibody and high sCD30 had the highest risk of subsequent graft failure (HR 43.4, p < 0.0001 and HR 18.1, p = 0.0008 for ELISA and Luminex, respectively). These data show that detection of HSA and serum sCD30 measured at least 1-year post-transplant provides valuable and predictive information regarding subsequent graft outcome.

Polymer on Top: Current Limits and Future Perspectives of Quantitatively Evaluating Surface Grafting.

PubMed

Michalek, Lukas; Barner, Leonie; Barner-Kowollik, Christopher

2018-03-07

Well-defined polymer strands covalently tethered onto solid substrates determine the properties of the resulting functional interface. Herein, the current approaches to determine quantitative grafting densities are assessed. Based on a brief introduction into the key theories describing polymer brush regimes, a user's guide is provided to estimating maximum chain coverage and-importantly-examine the most frequently employed approaches for determining grafting densities, i.e., dry thickness measurements, gravimetric assessment, and swelling experiments. An estimation of the reliability of these determination methods is provided via carefully evaluating their assumptions and assessing the stability of the underpinning equations. A practical access guide for comparatively and quantitatively evaluating the reliability of a given approach is thus provided, enabling the field to critically judge experimentally determined grafting densities and to avoid the reporting of grafting densities that fall outside the physically realistic parameter space. The assessment is concluded with a perspective on the development of advanced approaches for determination of grafting density, in particular, on single-chain methodologies. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An in vitro assessment of titanium functionalized with polysaccharides conjugated with vascular endothelial growth factor for enhanced osseointegration and inhibition of bacterial adhesion.

PubMed

Hu, Xuefeng; Neoh, Koon-Gee; Shi, Zhilong; Kang, En-Tang; Poh, Chyekhoon; Wang, Wilson

2010-12-01

The long-term success of orthopedic implants may be compromised by defective osseointegration and bacterial infection. An effective approach to minimize implant failure would be to modify the surface of the implant to make it habitable for bone-forming cells and anti-infective at the same time. In this in vitro study, the surfaces of titanium (Ti) substrates were functionalized by first covalently grafting either dopamine followed by carboxymethyl chitosan (CMCS) or hyaluronic acid-catechol (HAC). Vascular endothelial growth factor (VEGF) was then conjugated to the polysaccharide-grafted surface. Antibacterial assay with Staphylococcus aureus (S. aureus) showed that the polysaccharide-modified substrates significantly decrease bacterial adhesion. The CMCS-functionalized Ti demonstrated better antibacterial property than the HAC-functionalized Ti since CMCS is bactericidal while HA only inhibits the adhesion of bacteria without killing them. Osteoblast attachment, as well as alkaline phosphatase (ALP) activity and calcium deposition were enhanced by the immobilized VEGF on the polysaccharide-grafted Ti. Thus, Ti substrates modified with polysaccharides conjugated with VEGF can promote osteoblast functions and concurrently reduce bacterial adhesion. Since VEGF is also known to enhance angiogenesis, the VEGF-polysaccharide functionalized substrates will have promising applications in the orthopedic field. Copyright © 2010 Elsevier Ltd. All rights reserved.

Pancreas Transplant Venous Thrombosis: Role of Endovascular Interventions for Graft Salvage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stockland, Andrew H.; Willingham, Darrin L.; Paz-Fumagalli, Ricardo

2009-03-15

Venous thrombosis of pancreas transplant allografts often leads to graft loss. We evaluated the efficacy of emergent endovascular techniques to salvage thrombosed pancreatic allografts in a series of six patients. Of the 76 pancreas transplants performed between 2002 and 2006, six patients were diagnosed with venous thrombosis on MRI between 2 and 28 days posttransplant (mean, 9 days). Five patients were systemic-enteric (donor portal vein anastomosis to recipient iliac vein) and one patient was portal-enteric (donor portal vein anastomosis to recipient superior mesenteric vein). Conventional venography confirmed the diagnosis of venous thrombosis in all patients. One patient was treated withmore » catheter-directed venous thrombolysis and balloon thrombectomy. Another patient was treated with rheolytic thrombectomy alone. The remaining four patients were treated with a combination of these mechanical and thrombolytic techniques. Completion venography revealed >50% clot reduction and resumption of venous drainage in all patients. One patient required additional intervention 16 days later for recurrent thrombosis. Two patients required metal stent placement for anastomotic stenoses or kinks. One patient required pancreatectomy 36 h after attempted salvage secondary to a major hemorrhage and graft necrosis. Two patients recovered pancreatic function initially but lost graft function at 8 and 14 months, respectively, from severe chronic rejection. Patient survival was 100%, long-term graft survival was 50%, rethrombosis rate was 16.6%, and graft loss from rejection was 33%. In conclusion, early recognition and treatment of venous thrombosis after pancreas transplantation has acceptable morbidity and no mortality using short-term endovascular pharmacomechanical therapy.« less

Inhaled hydrogen gas therapy for prevention of lung transplant-induced ischemia/reperfusion injury in rats.

PubMed

Kawamura, Tomohiro; Huang, Chien-Sheng; Tochigi, Naobumi; Lee, Sungsoo; Shigemura, Norihisa; Billiar, Timothy R; Okumura, Meinoshin; Nakao, Atsunori; Toyoda, Yoshiya

2010-12-27

Successful abrogation of ischemia/reperfusion (I/R) injury of lung grafts could significantly improve short- and long-term outcomes for lung transplant (LTx) recipients. Hydrogen gas has potent antioxidant and antiapoptotic properties and has been recently used in number of experimental and clinical studies. The purpose of this research was to investigate whether inhaled hydrogen gas could reduce graft I/R injury during lung transplantation. Orthotopic left LTxs were performed in syngenic Lewis rats. Grafts were perfused with and stored in low potassium dextran solution at 4°C for 6 hr. The recipients received 100% O2 or 98% O2 with 2% N2, 2% He, or 2% H2 during surgery and 1 hr after reperfusion. The effects of hydrogen were assessed by functional, pathologic, and molecular analysis. Gas exchange was markedly impaired in animals exposed to 100% O2, 2% N2, or 2% He. Hydrogen inhalation attenuated graft injury as indicated by significantly improved gas exchange 2 hr after reperfusion. Graft lipid peroxidation was significantly reduced in the presence of hydrogen, demonstrating antioxidant effects of hydrogen in the transplanted lungs. Lung cold I/R injury causes the rapid production and release of several proinflammatory mediators and epithelial apoptosis. Exposure to 2% H2 significantly blocked the production of several proinflammatory mediators and reduced apoptosis with induction of the antiapoptotic molecules B-cell lymphoma-2 and B-cell lymphoma-extra large. Treatment of LTx recipients with inhaled hydrogen can prevent lung I/R injury and significantly improve the function of lung grafts after extended cold preservation, transplant, and reperfusion.

Two-stage liver transplantation using auxiliary laparoscopically harvested grafts in adults: Emphasizing the concept of "hypersmall graft nursing".

PubMed

Scatton, Olivier; Cauchy, François; Conti, Filomena; Perdigao, Fabiano; Massault, Pierre Philippe; Goumard, Claire; Soubrane, Olivier

2016-11-01

Living donor liver transplantation is limited by the donor's risk in case of right liver donation and by the risk of small-for-size syndrome on the recipient in case of left lobe transplantation. This study aimed at evaluating the feasibility and results of two-stage liver transplantation using auxiliary hyper small grafts harvested laparoscopically and discussing relevant technical insights and issues that still need to be overcome. Retrospective analysis involving two patients operated at a tertiary referral center. The recipients underwent left lateral sectionectomy and then auxillary liver transplantation using laparoscopically harvested left lateral section. The native right liver was transiently left in place to sustain the initially small functional graft functional during its hypertrophy. No donor experienced postoperative complication. After 7days, the hypertrophy rate was 112% (105-120). Doppler assessments during the first two postoperative weeks showed progressive portal vein inflow decrease in the right native livers and portal vein inflow increase in the grafts. Liver biopsies on postoperative day 7 showed no lesion of overperfusion. No recipient experienced liver failure or small-for-size syndrome. Second stage hepatectomy of the native liver was undertaken in one patient. In the other patient, biliary stenosis on postoperative day 30 precluded second stage hepatectomy. This patient required retransplantation after one year. The current strategy increases donor safety and may allow increasing the pool of available grafts. Refinements in the management of the native right liver are however required to improve the feasibility rate of this strategy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Methods for attaching polymerizable ceragenins to water treatment membranes using amine and amide linkages

DOEpatents

Hibbs, Michael; Altman, Susan J.; Jones, Howland D.T.; Savage, Paul B.

2013-10-15

This invention relates to methods for chemically grafting and attaching ceragenin molecules to polymer substrates; methods for synthesizing ceragenin-containing copolymers; methods for making ceragenin-modified water treatment membranes and spacers; and methods of treating contaminated water using ceragenin-modified treatment membranes and spacers. Ceragenins are synthetically produced antimicrobial peptide mimics that display broad-spectrum bactericidal activity. Alkene-functionalized ceragenins (e.g., acrylamide-functionalized ceragenins) can be attached to polyamide reverse osmosis membranes using amine-linking, amide-linking, UV-grafting, or silane-coating methods. In addition, silane-functionalized ceragenins can be directly attached to polymer surfaces that have free hydroxyls.

Methods for attaching polymerizable ceragenins to water treatment membranes using silane linkages

DOEpatents

Hibbs, Michael; Altman, Susan J.; Jones, Howland D. T.; Savage, Paul B.

2013-09-10

This invention relates to methods for chemically grafting and attaching ceragenin molecules to polymer substrates; methods for synthesizing ceragenin-containing copolymers; methods for making ceragenin-modified water treatment membranes and spacers; and methods of treating contaminated water using ceragenin-modified treatment membranes and spacers. Ceragenins are synthetically produced antimicrobial peptide mimics that display broad-spectrum bactericidal activity. Alkene-functionalized ceragenins (e.g., acrylamide-functionalized ceragenins) can be attached to polyamide reverse osmosis membranes using amine-linking, amide-linking, UV-grafting, or silane-coating methods. In addition, silane-functionalized ceragenins can be directly attached to polymer surfaces that have free hydroxyls.

Quantification of texture match of the skin graft: function and morphology of the stratum corneum.

PubMed

Inoue, K; Matsumoto, K

1986-01-01

In an attempt to analyze the "texture match" of grafted skin, functional and morphological aspects of the stratum corneum were studied using the Skin Surface Hydrometer (IBS Inc.) and the scanning electron microscope. The results showed that hygroscopicity and water holding capacity of the stratum corneum played a crucial role in making the skin surface soft and smooth. Morphologically there were regional differences in the surface pattern and the mean area of corneocytes, suggesting that these differences affect skin texture. It is suggested that the present functional and morphological studies of the stratum corneum can provide a quantitative measure of the "texture match".

Vγ4 γδ T Cells Provide an Early Source of IL-17A and Accelerate Skin Graft Rejection.

PubMed

Li, Yashu; Huang, Zhenggen; Yan, Rongshuai; Liu, Meixi; Bai, Yang; Liang, Guangping; Zhang, Xiaorong; Hu, Xiaohong; Chen, Jian; Huang, Chibing; Liu, Baoyi; Luo, Gaoxing; Wu, Jun; He, Weifeng

2017-12-01

Activated γδ T cells have been shown to accelerate allograft rejection. However, the precise role of skin-resident γδ T cells and their subsets-Vγ5 (epidermis), Vγ1, and Vγ4 (dermis)-in skin graft rejection have not been identified. Here, using a male to female skin transplantation model, we demonstrated that Vγ4 T cells, rather than Vγ1 or Vγ5 T cells, accelerated skin graft rejection and that IL-17A was essential for Vγ4 T-cell-mediated skin graft rejection. Moreover, we found that Vγ4 T cells were required for early IL-17A production in the transplanted area, both in skin grafts and in the host epidermis around grafts. Additionally, the chemokine (C-C motif) ligand 20-chemokine receptor 6 pathway was essential for recruitment of Vγ4 T cells to the transplantation area, whereas both IL-1β and IL-23 induced IL-17A production from infiltrating cells. Lastly, Vγ4 T-cell-derived IL-17A promoted the accumulation of mature dendritic cells in draining lymph nodes to subsequently regulate αβ T-cell function after skin graft transplantation. Taken together, our data reveal that Vγ4 T cells accelerate skin graft rejection by providing an early source of IL-17A. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Left Lobe Auxiliary Liver Transplantation for End-stage Hepatitis B Liver Cirrhosis.

PubMed

Wang, S-F; Chen, X-P; Chen, Z-S; Wei, L; Dong, S-L; Guo, H; Jiang, J-P; Teng, W-H; Huang, Z-Y; Zhang, W-G

2017-06-01

Auxiliary liver transplantation (ALT) for hepatitis B virus (HBV)-related liver cirrhosis previously showed poor results, because the native liver was a significant source of HBV recurrence and the graft could be rapidly destroyed by HBV infection in an immunosuppressive condition. Four patients with HBV-related liver cirrhosis were unable to undergo orthotopic liver transplantation because the only available grafts of left lobe were too small. Under entecavir-based anti-HBV treatment, they underwent ALT in which the recipient left liver was removed and the small left lobe graft was implanted in the corresponding space. The mean graft weight/recipient weight was 0.49% (range, 0.38%-0.55%). One year after transplantation, the graft sizes were increased to 273% and the remnant livers were decreased to 44%. Serum HBV DNA was persistently undetectable. Periodic graft biopsy showed no signs of tissue injury and negative immunostaining for hepatitis B surface antigen and hepatitis B core antigen. After a mean follow-up period of 21 months, all patients live well with normal graft function. Our study suggests that ALT for HBV-related liver cirrhosis is feasible under entecavir-based anti-HBV treatment. Successful application of small left livers in end-stage liver cirrhosis may significantly increase the pool of left liver grafts for adult patients. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

Reversal of Diabetes by Islet Transplantation: Vulnerability of the Established Allograft

NASA Astrophysics Data System (ADS)

Bowen, K. M.; Prowse, S. J.; Lafferty, K. J.

1981-09-01

Nonspecific stimulation of the immune system of CBA mice carrying a functional BALB/c islet allograft failed to trigger graft rejection. Only three of six animals rejected their graft when injected intravenously with 105, 106, and 107 peritoneal cells of BALB/c origin over a 3-month period commencing 100 days after transplantation.

Ankle arthrodesis with bone graft after distal tibia resection for bone tumors.

PubMed

Campanacci, Domenico Andrea; Scoccianti, Guido; Beltrami, Giovanni; Mugnaini, Marco; Capanna, Rodolfo

2008-10-01

Treatment of distal tibial tumors is challenging due to the scarce soft tissue coverage of this area. Ankle arthrodesis has proven to be an effective treatment in primary and post-traumatic joint arthritis, but few papers have addressed the feasibility and techniques of ankle arthrodesis in tumor surgery after long bone resections. Resection of the distal tibia and reconstruction by ankle fusion using non-vascularized structural bone grafts was performed in 8 patients affected by malignant (5 patients) or aggressive benign (3 patients) tumors. Resection length of the tibia ranged from 5 to 21 cm. Bone defects were reconstructed with cortical structural autografts (from contralateral tibia) or allografts or both, plus autologous bone chips. Fixation was accomplished by antegrade nailing (6 cases) or plating (2~cases). All the arthrodesis successfully healed. At followup ranging from 23 to 113 months (average 53.5), all patients were alive. One local recurrence was observed with concomitant deep infection (a below-knee amputation was performed). Mean functional MSTS score of the seven available patients was 80.4% (range, 53 to 93). Resection of the distal tibia and arthrodesis of the ankle with non-vascularized structural bone grafts, combined with autologous bone chips, can be an effective procedure in bone tumor surgery with durable and satisfactory functional results. In shorter resections, autologous cortical structural grafts can be used; in longer resections, allograft structural bone grafts are needed.