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Sample records for delayed graft function

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

    PubMed Central

    Schulz, Tim; Pries, Alexandra; Kapischke, Matthias

    2016-01-01

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

  2. 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.

  3. Ultrasonic imaging characteristics of transplanted kidneys with delayed graft function.

    PubMed

    Liang, W X; Cai, M J; Jiang, L; Xie, Y Q; Yuan, W L; Zhang, H

    2014-08-29

    We investigated the ultrasonic imaging characteristics of transplanted kidneys with delayed graft function (DGF). Ultrasonography was performed in 44 patients after kidney transplantation, and a time-intensity analysis was performed to compare the differences between patients with normal graft function (NGF) and those with DGF. Compared with the NGF group, the DGF group had earlier arrival time, shorter time to peak, and higher arrival intensity and peak intensity (P < 0.05). The variation-of-intensity parameters in different renal cortices increased, whereas the variation-of-time parameter decreased, in those with DGF (P < 0.05). In conclusion, compared with the NGF group, the microcirculation perfusion of transplanted kidneys in the DGF group showed higher perfusion with earlier arrival time, shorter time to peak, and higher arrival intensity and peak intensity. In addition, the intensity variations of contrast agent in different renal cortices from patients with DGF were greater, whereas the variations in perfusion time were smaller than those in patients with NGF.

  4. Vasodilatation vs. immunotherapy to prevent delayed graft function: delayed graft function as an indication of immune activation.

    PubMed

    McCune, Thomas R; Wombolt, Duane G; Whelan, Thomas V; Thacker, Leroy R; Colonna, John O

    2005-01-01

    Delayed renal allograft function (DGF) is a factor for acute rejection and chronic allograft nephropathy. Cold ischemia time (CIT) is associated with an increased in DGF. Twenty patients receiving allografts with CIT>12 were enrolled in a double-blinded, randomized (1:1), placebo-controlled study to assess vasodilatation with fenoldopam (Abbott; dopamine-1 receptor agonist) on DGF. Fenoldopam infusion began at arterial anastomosis at 0.025 microg/kg/min and titrated to 0.1 microg/kg/min continued for 48 h postop (PO). Immunosuppression included steriods, MMF, and calcinurin inhibitors begun 36 h PO. Antibody induction (AI) using antithymocyte globulin (rabbit) (AT-G(r); Sangstat) was added halfway through the study to African-Americans and for PRA>40%. The need for dialysis, cumulative urine output (UOP), and creatinine (Cr) at PO day 7, 14, and 30 were compared. Eighteen patients completed the study drug infusion. Demographics of groups were not different. There was no difference between fenoldopam and controls for dialysis, UOP at 48 and 72 h, or Cr at 7, 14, or 30 days. There was a difference in UOP when AI (n=7) was compared to non-AI (n=11). At 48 h non-AI UOP 4796+/-3284 ml compared to AI UOP 8960+/-5130 ml (p=0.050). At 72 h, non-AI patients had UOP of 6824+/-4547 ml compared to AI patients with UOP of 12196+/-5868 ml (p=0.044). There was a trend to a lower Cr at day 7 for AI 2.7+/-2.1mg/dl compared to 4.9+/-3.0 mg/dl in non-AI (p=0.11). There was no difference in dialysis or Cr at day 14 and 30 between the AI and non-AI patients. AI with AT-G(r) significantly increases UOP in allografts with CIT>12 h, whereas vasodilatation did not. Therapy for DGF may include AT-G(r) AI.

  5. Effects of early versus delayed excision and grafting on the return of the burned hand function

    PubMed Central

    Salehi, Seyed Hamid; Fatemi, Mohammad Javad; Sedghi, Maryam; Niazi, Mitra

    2016-01-01

    Background: Despite a general consensus regarding the impacts of early excision and grafting (EE and G) of burned hand on the reducing of treatment cost and hospital stay, there are some controversial issues about its effect on the outcome of hand function. This study conducted to compare the results of the EE and G and delayed skin grafting in deep hand burns regarding the hand functional outcome. Materials and Methods: This study was conducted from April 2012 to November 2013 in sixty patients with deep thermal burns of the dorsal hand with total body surface area (TBSA) <20% who were admitted to special burn hospital. After standard primary burn care and resuscitation, necessary procedures (EE and G or more conservative treatment) were performed based on the patients’ conditions. The patients were placed into early excision (No. =30) and delayed excision group (No. =30). Total active motion (TAM) of fingers, grip strength of the hand and the assessment of disabilities of the arm, shoulder and hand questionnaire, were measured in all patients 6 months after grafting. Results: The average percentage of TBSA in the EE and G group was more than the delayed excision group (17.34% ±5.12% vs. 15.64% ±5.83%), this difference was not significant (P = 0.23). After 6 months, the average of the TAM and grip strength in the EE and G group was significantly more than that of the delayed group (P < 0.0001 and P = 0.019). Conclusion: The present study showed that EE and G with proper physical therapy and rehabilitation management provides a higher functional outcome in dorsal deep burned hand. PMID:28250786

  6. Intraoperative administration of inhaled carbon monoxide reduces delayed graft function in kidney allografts in Swine.

    PubMed

    Hanto, D W; Maki, T; Yoon, M H; Csizmadia, E; Chin, B Y; Gallo, D; Konduru, B; Kuramitsu, K; Smith, N R; Berssenbrugge, A; Attanasio, C; Thomas, M; Wegiel, B; Otterbein, L E

    2010-11-01

    Ischemia/reperfusion injury and delayed graft function (DGF) following organ transplantation adversely affect graft function and survival. A large animal model has not been characterized. We developed a pig kidney allograft model of DGF and evaluated the cytoprotective effects of inhaled carbon monoxide (CO). We demonstrate that donor warm ischemia time is a critical determinant of DGF as evidenced by a transient (4-6 days) increase in serum creatinine and blood urea nitrogen following transplantation before returning to baseline. CO administered to recipients intraoperatively for 1 h restored kidney function more rapidly versus air-treated controls. CO reduced acute tubular necrosis, apoptosis, tissue factor expression and P-selectin expression and enhanced proliferative repair as measured by phosphorylation of retinol binding protein and histone H3. Gene microarray analyses with confirmatory PCR of biopsy specimens showed that CO blocked proinflammatory gene expression of MCP-1 and heat shock proteins. In vitro in pig renal epithelial cells, CO blocks anoxia-reoxygenation-induced cell death while promoting proliferation. This large animal model of DGF can be utilized for testing therapeutic strategies to reduce or prevent DGF in humans. The efficacy of CO on improving graft function posttransplant validates the model and offers a potentially important therapeutic strategy to improve transplant outcomes.

  7. The transcriptome of the implant biopsy identifies donor kidneys at increased risk of delayed graft function.

    PubMed

    Mueller, T F; Reeve, J; Jhangri, G S; Mengel, M; Jacaj, Z; Cairo, L; Obeidat, M; Todd, G; Moore, R; Famulski, K S; Cruz, J; Wishart, D; Meng, C; Sis, B; Solez, K; Kaplan, B; Halloran, P F

    2008-01-01

    Improved assessment of donor organ quality at time of transplantation would help in management of potentially usable organs. The transcriptome might correlate with risk of delayed graft function (DGF) better than conventional risk factors. Microarray results of 87 consecutive implantation biopsies taken postreperfusion in 42 deceased (DD) and 45 living (LD) donor kidneys were compared to clinical and histopathology-based scores. Unsupervised analysis separated the 87 kidneys into three groups: LD, DD1 and DD2. Kidneys in DD2 had a greater incidence of DGF (38.1 vs. 9.5%, p < 0.05) than those in DD1. Clinical and histopathological risk scores did not discriminate DD1 from DD2. A total of 1051 transcripts were differentially expressed between DD1 and DD2, but no transcripts separated DGF from immediate graft function (adjusted p < 0.01). Principal components analysis revealed a continuum from LD to DD1 to DD2, i.e. from best to poorest functioning kidneys. Within DD kidneys, the odds ratio for DGF was significantly increased with a transcriptome-based score and recipient age (p < 0.03) but not with clinical or histopathologic scores. The transcriptome reflects kidney quality and susceptibility to DGF better than available clinical and histopathological scoring systems.

  8. Biomarkers of delayed graft function as a form of acute kidney injury in kidney transplantation

    PubMed Central

    Malyszko, Jolanta; Lukaszyk, Ewelina; Glowinska, Irena; Durlik, Magdalena

    2015-01-01

    Renal transplantation ensures distinct advantages for patients with end-stage kidney disease. However, in some cases early complications can lead to allograft dysfunction and consequently graft loss. One of the most common early complications after kidney transplantation is delayed graft function (DGF). Unfortunately there is no effective treatment for DGF, however early diagnosis of DGF and therapeutic intervention (eg modification of immunosuppression) may improve outcome. Therefore, markers of acute kidney injury are required. Creatinine is a poor biomarker for kidney injury due principally to its inability to help diagnose early acute renal failure and complete inability to help differentiate among its various causes. Different urinary and serum proteins have been intensively investigated as possible biomarkers in this setting. There are promising candidate biomarkers with the ability to detect DGF. We focused on emerging biomarkers of DGF with NGAL is being the most studied followed by KIM-1, L-FABP, IL-18, and others. However, large randomized studies are needed to establish the value of new, promising biomarkers, in DGF diagnosis, prognosis and its cost-effectiveness. PMID:26175216

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

    PubMed

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

    2011-01-01

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

  10. Karyopherins: potential biological elements involved in the delayed graft function in renal transplant recipients

    PubMed Central

    2014-01-01

    Background Immediately after renal transplantation, patients experience rapid and significant improvement of their clinical conditions and undergo considerable systemic and cellular modifications. However, some patients present a slow recovery of the renal function commonly defined as delayed graft function (DGF). Although clinically well characterized, the molecular mechanisms underlying this condition are not totally defined, thus, we are currently missing specific clinical markers to predict and to make early diagnosis of this event. Methods We investigated, using a pathway analysis approach, the transcriptomic profile of peripheral blood mononuclear cells (PBMC) from renal transplant recipients with DGF and with early graft function (EGF), before (T0) and 24 hours (T24) after transplantation. Results Bioinformatics/statistical analysis showed that 15 pathways (8 up-regulated and 7 down-regulated) and 11 pathways (5 up-regulated and 6 down-regulated) were able to identify DGF patients at T0 and T24, respectively. Interestingly, the most up-regulated pathway at both time points was NLS-bearing substrate import into nucleus, which includes genes encoding for several subtypes of karyopherins, a group of proteins involved in nucleocytoplasmic transport. Signal transducers and activators of transcription (STAT) utilize karyopherins-alpha (KPNA) for their passage from cytoplasm into the nucleus. In vitro functional analysis demonstrated that in PBMCs of DGF patients, there was a significant KPNA-mediated nuclear translocation of the phosphorylated form of STAT3 (pSTAT3) after short-time stimulation (2 and 5 minutes) with interleukin-6. Conclusions Our study suggests the involvement, immediately before transplantation, of karyopherin-mediated nuclear transport in the onset and development of DGF. Additionally, it reveals that karyopherins could be good candidates as potential DGF predictive clinical biomarkers and targets for pharmacological interventions in renal

  11. Predictive model for delayed graft function based on easily available pre-renal transplant variables.

    PubMed

    Zaza, Gianluigi; Ferraro, Pietro Manuel; Tessari, Gianpaolo; Sandrini, Silvio; Scolari, Maria Piera; Capelli, Irene; Minetti, Enrico; Gesualdo, Loreto; Girolomoni, Giampiero; Gambaro, Giovanni; Lupo, Antonio; Boschiero, Luigino

    2015-03-01

    Identification of pre-transplant factors influencing delayed graft function (DGF) could have an important clinical impact. This could allow clinicians to early identify dialyzed chronic kidney disease (CKD) patients eligible for special transplant programs, preventive therapeutic strategies and specific post-transplant immunosuppressive treatments. To achieve these objectives, we retrospectively analyzed main demographic and clinical features, follow-up events and outcomes registered in a large dedicated dataset including 2,755 patients compiled collaboratively by four Italian renal/transplant units. The years of transplant ranged from 1984 to 2012. Statistical analysis clearly demonstrated that some recipients' characteristics at the time of transplantation (age and body weight) and dialysis-related variables (modality and duration) were significantly associated with DGF development (p ≤ 0.001). The area under the receiver-operating characteristic (ROC) curve of the final model based on the four identified variables predicting DGF was 0.63 (95 % CI 0.61, 0.65). Additionally, deciles of the score were significantly associated with the incidence of DGF (p value for trend <0.001). Therefore, in conclusion, in our study we identified a pre-operative predictive model for DGF, based on inexpensive and easily available variables, potentially useful in routine clinical practice in most of the Italian and European dialysis units.

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

    PubMed Central

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

    2016-01-01

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

  13. Prediction of delayed graft function by means of a novel web-based calculator: a single-center experience.

    PubMed

    Rodrigo, E; Miñambres, E; Ruiz, J C; Ballesteros, A; Piñera, C; Quintanar, J; Fernández-Fresnedo, G; Palomar, R; Gómez-Alamillo, C; Arias, M

    2012-01-01

    Renal failure persisting after renal transplant is known as delayed graft function (DGF). DGF predisposes the graft to acute rejection and increases the risk of graft loss. In 2010, Irish et al. developed a new model designed to predict DGF risk. This model was used to program a web-based DGF risk calculator, which can be accessed via http://www.transplantcalculator.com . The predictive performance of this score has not been tested in a different population. We analyzed 342 deceased-donor adult renal transplants performed in our hospital. Individual and population DGF risk was assessed using the web-based calculator. The area under the ROC curve to predict DGF was 0.710 (95% CI 0.653-0.767, p < 0.001). The "goodness-of-fit" test demonstrates that the DGF risk was well calibrated (p = 0.309). Graft survival was significantly better for patients with a lower DGF risk (5-year survival 71.1% vs. 60.1%, log rank p = 0.036). The model performed well with good discrimination ability and good calibration to predict DGF in a single transplant center. Using the web-based DGF calculator, we can predict the risk of developing DGF with a moderate to high degree of certainty only by using information available at the time of transplantation.

  14. Associations of Perfusate Biomarkers and Pump Parameters With Delayed Graft Function and Deceased Donor Kidney Allograft Function.

    PubMed

    Parikh, C R; Hall, I E; Bhangoo, R S; Ficek, J; Abt, P L; Thiessen-Philbrook, H; Lin, H; Bimali, M; Murray, P T; Rao, V; Schröppel, B; Doshi, M D; Weng, F L; Reese, P P

    2016-05-01

    Hypothermic machine perfusion (HMP) is increasingly used in deceased donor kidney transplantation, but controversy exists regarding the value of perfusion biomarkers and pump parameters for assessing organ quality. We prospectively determined associations between perfusate biomarkers (neutrophil gelatinase-associated lipocalin [NGAL], kidney injury molecule 1, IL-18 and liver-type fatty acid-binding protein [L-FABP]) and pump parameters (resistance and flow) with outcomes of delayed graft function (DGF) and 6-mo estimated GFR (eGFR). DGF occurred in 230 of 671 (34%) recipients. Only 1-h flow was inversely associated with DGF. Higher NGAL or L-FABP concentrations and increased resistance were inversely associated with 6-mo eGFR, whereas higher flow was associated with higher adjusted 6-mo eGFR. Discarded kidneys had consistently higher median resistance and lower median flow than transplanted kidneys, but median perfusate biomarker concentrations were either lower or not significantly different in discarded compared with transplanted kidneys. Notably, most recipients of transplanted kidneys with isolated "undesirable" biomarker levels or HMP parameters experienced acceptable 6-mo allograft function, suggesting these characteristics should not be used in isolation for discard decisions. Additional studies must confirm the utility of combining HMP measurements with other characteristics to assess kidney quality.

  15. Risk factors and outcomes of delayed graft function in renal transplant recipients receiving a steroid sparing immunosuppression protocol

    PubMed Central

    Willicombe, Michelle; Rizzello, Anna; Goodall, Dawn; Papalois, Vassilios; McLean, Adam G; Taube, David

    2017-01-01

    AIM To analyse the risk factors and outcomes of delayed graft function (DGF) in patients receiving a steroid sparing protocol. METHODS Four hundred and twenty-seven recipients of deceased donor kidney transplants were studied of which 135 (31.6%) experienced DGF. All patients received monoclonal antibody induction with a tacrolimus based, steroid sparing immunosuppression protocol. RESULTS Five year patient survival was 87.2% and 94.9% in the DGF and primary graft function (PGF) group respectively, P = 0.047. Allograft survival was 77.9% and 90.2% in the DGF and PGF group respectively, P < 0.001. Overall rejection free survival was no different between the DGF and PGF groups with a 1 and 5 year rejection free survival in the DGF group of 77.7% and 67.8% compared with 81.3% and 75.3% in the PGF group, P = 0.19. Patients with DGF who received IL2 receptor antibody induction were at significantly higher risk of rejection in the early post-transplant period than the group with DGF who received alemtuzumab induction. On multivariate analysis, risk factors for DGF were male recipients, recipients of black ethnicity, circulatory death donation, preformed DSA, increasing cold ischaemic time, older donor age and dialysis vintage. CONCLUSION Alemtuzumab induction may be of benefit in preventing early rejection episodes associated with DGF. Prospective trials are required to determine optimal immunotherapy protocols for patients at high risk of DGF. PMID:28280693

  16. The impact of meeting donor management goals on the development of delayed graft function in kidney transplant recipients.

    PubMed

    Malinoski, D J; Patel, M S; Ahmed, O; Daly, M C; Mooney, S; Graybill, C O; Foster, C E; Salim, A

    2013-04-01

    Many organ procurement organizations (OPOs) utilize preset critical care endpoints as donor management goals (DMGs) in order to standardize care and improve outcomes. The objective of this study was to determine the impact of meeting DMGs on delayed graft function (DGF) in renal transplant recipients. All eight OPOs of the United Network for Organ Sharing Region 5 prospectively implemented nine DMGs in every donor after neurologic determination of death (DNDD). "DMGs met" was defined a priori as achieving any seven of the nine DMGs and this was recorded at the time of consent for donation to reflect donor hospital ICU management, 12-18 h later, and prior to organ recovery. Multivariable analyses were performed to identify independent predictors of DGF (dialysis in the first week after transplantation) with a p<0.05. A total of 722 transplanted kidneys from 492 DNDDs were included. A total of 28% developed DGF. DMGs were met at consent in 14%, 12-18 h in 32% and prior to recovery in 38%. DGF was less common when DMGs were met at consent (17% vs. 30%, p=0.007). Independent predictors of DGF were age, Cr and cold ischemia time, while meeting DMGs at consent was significantly protective. The management of potential organ donors prior to consent affects outcomes and should remain a priority in the intensive care unit.

  17. 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.

  18. A randomized trial of basiliximab with three different patterns of cyclosporin A initiation in renal transplant from expanded criteria donors and at high risk of delayed graft function.

    PubMed

    Andrés, Amado; Marcén, Roberto; Valdés, Francisco; Plumed, Jaime Sánchez; Solà, Ricard; Errasti, Pedro; Lauzurica, Ricardo; Pallardó, Luis; Bustamante, Jesús; Amenábar, Juan José; Plaza, Juan José; Gómez, Ernesto; Grinyó, Josep Maria; Rengel, Manuel; Puig, Josep Maria; Sanz, Aurelio; Asensio, Concepción; Andrés, Inés

    2009-01-01

    This study assays therapy with basiliximab and different patterns of cyclosporin A (CsA) initiation in renal transplant (RT) recipients from expanded criteria donors (ECD) and at high risk of delayed graft function (DGF). A multicentre six-month open-label randomized trial with three parallel groups treated with basiliximab plus steroids, mycophenolate mofetil and different patterns of CsA initiation: early within 24 h post-RT at 3 mg/kg/d (Group 1; n = 38), and at 5 mg/kg/d (Group 2; n = 40), or delayed after 7-10 d at 5 mg/kg/d (Group 3; n = 36). There were no differences among groups in six months GFR (43.1 +/- 12, 48.0 +/- 14 and 47.2 +/- 17 mL/min, respectively), DGF (Group 1: 31%, Group 2: 37%, Group 3: 42%), nor biopsy-proven acute rejection, although clinically treated and biopsy-proven acute rejection was significantly higher in Group 3 (25%) vs. Group 1 (5.3%, p < 0.05). At six months no differences were observed in death-censored graft survival or patient survival. Induction therapy with basiliximab and three CsA-ME initiation patterns in RT recipients from ECD and at high risk of DGF presented good renal function and graft survival at six months. Late onset group did not achieve improvement in DGF rate and showed a higher incidence of clinically treated and biopsy-proven acute rejection.

  19. Incidence and factors associated with delayed graft function in renal transplantation at Carlos Van Buren Hospital, January 2000 to June 2008.

    PubMed

    Sáinz, M M; Toro, J C; Poblete, H B; Perez, L F; Nicovani, V H; Carrera, M G

    2009-01-01

    Delayed graft function (DGF) is defined as the need for dialysis within the first week after renal transplantation, and slow graft function as persistence of serum creatinine concentration of at least 3 mg/dL on day 5 after the procedure. In the present study, we analyzed the incidence and risk factors for DGF at our center. This retrospective study included 106 patients who underwent renal transplantation between January 2000 and June 2008. Of these, 11 patients were excluded. Two of the remaining 95 patients received organs from living donors, and 93 received cadaver organs. Variables analyzed included donor age, cause of death, cause of chronic renal failure, recipient age, method and time of long-term renal replacement therapy, residual diuresis, panel of reactive antibodies (PRA), HLA mismatch, sex compatibility, cold and warm ischemia times, biopsy-confirmed episodes of acute rejection, urine output in the operating room and in the first 24 hours after the procedure, and intraoperative induction therapy. Data were analyzed using the chi(2) and Fisher exact tests and analysis of variance, and are given as mean (SD) and frequency. Variables associated with DGF at univariate analysis (P < .05) were divided between risk factors and predictors of DGF for inclusion in logistic regression models. The incidence of DGF was 32.6%; slow graft function, 16.8%; and immediate graft function, 50.5%. Cold ischemia time longer than 20 hours (P = .02) and donor age (P = .008) were directly associated with DGF. Twenty-four-hour urine output was a strong predictor of DGF. Patients with DGF demonstrated a 25% incidence of an episode of acute rejection before discharge from the hospital. No difference in DGF was observed for use of intraoperative induction therapy.

  20. FTY720 and everolimus in de novo renal transplant patients at risk for delayed graft function: results of an exploratory one-yr multicenter study.

    PubMed

    Tedesco-Silva, H; Lorber, M I; Foster, C E; Sollinger, H W; Mendez, R; Carvalho, D B; Shapiro, R; Rajagopalan, P R; Mayer, H; Slade, J; Kahan, B D

    2009-01-01

    This exploratory, multicenter, open-label study evaluated the efficacy and safety of FTY720, as a part of an immunosuppressive regimen, in combination with everolimus and steroids in de novo renal transplant recipients at increased risk of delayed graft function (DGF). Patients received FTY720 (5 mg) and everolimus (4 mg) 2-12 h pre-transplantation, followed by 2.5 mg/d FTY720 and concentration-controlled everolimus (4-8 ng/mL) post-transplant for 12 months. Induction therapy was prohibited. After enrollment of 56 of the planned 200 patients between 2000 and 2002, the recruitment was terminated. The primary endpoint, rate of graft loss, or death at three months was 15.4% and the biopsy-confirmed acute rejection was 42.3%. Death or graft loss at 12 months in the DGF and non-DGF arms was 36.0% and 25.9%, respectively. The mean estimated creatinine clearance at three months was 63 and 55 mL/min in the non-DGF and DGF groups, respectively, while at 12 months it was 56 mL/min in both the groups. Although there was no comparator arm, the results from this exploratory study (compared with data from other phases II and III trials) indicated no apparent benefits of FTY720-based regimens for prevention of acute rejection and preservation of renal function in renal transplant recipients at high risk of DGF.

  1. Spreader Grafts in Functional Rhinoplasty.

    PubMed

    Kim, Leslie; Papel, Ira D

    2016-02-01

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

  2. Treatment of delayed/nonunion of scaphoid waist with Synthes cannulated scaphoid screw and bone graft.

    PubMed

    Inaparthy, P K; Nicholl, J E

    2008-12-01

    Fracture of the scaphoid bone is the most common fracture of the carpus, and frequently, diagnosis is delayed. The unique anatomy and blood supply of the scaphoid itself predisposes to delayed union or nonunion. The Synthes scaphoid screw is a cannulated headed screw, which provides superior compression compared with some other devices used to internally fix scaphoid nonunions. Our aim was to conduct a retrospective study looking at the union rate, time to union, and complications and correlating the outcome of treatment against the delay between injury and surgery and location of the fracture within the bone. This study is a review of a cohort of 30 patients treated with a cannulated Synthes scaphoid screw and corticocancellous bone grafting for scaphoid waist delayed union and nonunion at our center. We achieved 86% overall union rate. The patients with delayed union achieved a 100% union rate. Three out of four patients with persistent nonunion after surgery reported no pain and improved function. The failure rate was 75% in patients who had sustained their fracture more than 5 years previously. Our study demonstrates that delayed union of scaphoid waist fractures and scaphoid waist nonunions present for less than 5 years can be successfully treated by fracture compression and bone grafting.

  3. Treatment of Delayed/Nonunion of Scaphoid Waist with Synthes Cannulated Scaphoid Screw and Bone Graft

    PubMed Central

    Nicholl, J. E.

    2008-01-01

    Fracture of the scaphoid bone is the most common fracture of the carpus, and frequently, diagnosis is delayed. The unique anatomy and blood supply of the scaphoid itself predisposes to delayed union or nonunion. The Synthes scaphoid screw is a cannulated headed screw, which provides superior compression compared with some other devices used to internally fix scaphoid nonunions. Our aim was to conduct a retrospective study looking at the union rate, time to union, and complications and correlating the outcome of treatment against the delay between injury and surgery and location of the fracture within the bone. This study is a review of a cohort of 30 patients treated with a cannulated Synthes scaphoid screw and corticocancellous bone grafting for scaphoid waist delayed union and nonunion at our center. We achieved 86% overall union rate. The patients with delayed union achieved a 100% union rate. Three out of four patients with persistent nonunion after surgery reported no pain and improved function. The failure rate was 75% in patients who had sustained their fracture more than 5 years previously. Our study demonstrates that delayed union of scaphoid waist fractures and scaphoid waist nonunions present for less than 5 years can be successfully treated by fracture compression and bone grafting. PMID:18780015

  4. A Delay between Motor Cortex Lesions and Neuronal Transplantation Enhances Graft Integration and Improves Repair and Recovery.

    PubMed

    Péron, Sophie; Droguerre, Marine; Debarbieux, Franck; Ballout, Nissrine; Benoit-Marand, Marianne; Francheteau, Maureen; Brot, Sébastien; Rougon, Geneviève; Jaber, Mohamed; Gaillard, Afsaneh

    2017-02-15

    We previously reported that embryonic motor cortical neurons transplanted immediately after lesions in the adult mouse motor cortex restored damaged motor cortical pathways. A critical barrier hindering the application of transplantation strategies for a wide range of traumatic injuries is the determination of a suitable time window for therapeutic intervention. Here, we report that a 1 week delay between the lesion and transplantation significantly enhances graft vascularization, survival, and proliferation of grafted cells. More importantly, the delay dramatically increases the density of projections developed by grafted neurons and improves functional repair and recovery as assessed by intravital dynamic imaging and behavioral tests. These findings open new avenues in cell transplantation strategies as they indicate successful brain repair may occur following delayed transplantation.SIGNIFICANCE STATEMENT Cell transplantation represents a promising therapy for cortical trauma. We previously reported that embryonic motor cortical neurons transplanted immediately after lesions in the adult mouse motor cortex restored damaged cortical pathways. A critical barrier hindering the application of transplantation strategies for a wide range of traumatic injuries is the determination of a suitable time window for therapeutic intervention. We demonstrate that a 1 week delay between the lesion and transplantation significantly enhances graft vascularization, survival, proliferation, and the density of the projections developed by grafted neurons. More importantly, the delay has a beneficial impact on functional repair and recovery. These results impact the effectiveness of transplantation strategies in a wide range of traumatic injuries for which therapeutic intervention is not immediately feasible.

  5. Endovascular Management of Delayed Complete Graft Thrombosis After Endovascular Aneurysm Repair

    SciTech Connect

    Thurley, Peter D.; Glasby, Michael J.; Pollock, John G.; Bungay, Peter; Nunzio, Mario De; El-Tahir, Amin M.; Quarmby, John W.

    2010-08-15

    Graft thrombosis rates after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms vary widely in published series. When thrombosis does occur, it usually involves a single limb and occurs within 3 months of stent-graft insertion. If the entire endoprosthesis is thrombosed, treatment may be challenging because femoro-femoral crossover graft insertion is not an option and a greater volume of thrombus is present, thus making thrombolysis more difficult. We present two cases of delayed thrombosis after EVAR involving the entire stent-graft. These were successfully treated by a combined surgical and endovascular technique, and patency has been maintained in both cases to date.

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

    PubMed

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

    2006-09-01

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

  7. Grafting functional antioxidants on highly crosslinked polyethylene

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  8. Comparative Analysis of Early Excision and Grafting vs Delayed Grafting in Burn Patients in a Developing Country.

    PubMed

    Puri, Vinita; Khare, Nishant A; Chandramouli, M V; Shende, Nilesh; Bharadwaj, Sumit

    2016-01-01

    The present study attempts to compare how the patients who undergo early excision and grafting behave as compared with patients who are treated along usual conservative lines of management in centers where the resources are less than optimal. The data of 20 female patients were analyzed. Age of the patients ranged between 20 and 30 years, percentage area burn ranged between 20 and 40%, and percentage area resurfaced by skin grafting 5 to 10%. The patients were divided into two groups of 10 patients each. Group I included those patients who underwent early excision and grafting within 5 days of burn injury. Group II included those patients who were treated conservatively and the residual raw area was grafted 3 weeks or more after sustaining the burn. The two groups were compared for the amount of blood loss, transfusion requirement, graft take, and the total hospital stay. Statistical significance was tested by the application of Mann-Whitney U test. The mean percentage area burn was 29.1 ± 5.6% in group I and 24.7 ± 4.9% in group II. Mean percentage area resurfaced by skin grafting in group I was 9.4 ± 2.3% and 8.1 ± 1.6% in group II. Graft take in group I was 90 ± 7.8%, whereas that in group II was 95 ± 6.7%. Mean blood loss in group I and group II was 346 ± 17.6 ml and 241 ± 14.7 ml respectively. (P = .001). Mean transfusion requirement in the perioperative period was 1.6 pints in group I and 1.1 pints in group II. The mean hospital stay in the patients who underwent early excision and grafting was 15.1 ± 4.1 days, whereas that in the patients who underwent delayed grafting was 36.2 ± 6.3 days (P = .001). Early excision and grafting decreases the hospital stay of burn patients. The present study suggests that it has a definite applicability even in places where the resources might be less than optimal.

  9. Split skin graft application over an integrating, biodegradable temporizing polymer matrix: immediate and delayed.

    PubMed

    Greenwood, John Edward; Dearman, Bronwyn Louise

    2012-01-01

    The objective of this study is to further investigate the NovoSorb™ biodegradable polyurethane in generating dermal scaffolds; to perform a pilot study comparing the previously used spun mat against a recently developed NovoSorb™ foam, ascertaining the optimum structure of the matrix; and to evaluate the successful matrix as an immediate adjunct to split skin grafting and as a temporizing matrix in a prospective six-pig study. A pilot study comparing a previously investigated form of the polymer (spun mat) against a new structural form, a foam, was performed. This was followed by a six-pig study of the foam matrix with three treatment arms-autologous split skin graft alone, polymer foam with immediate engraftment, and polymer foam with delayed engraftment. The foams allowed less wound contraction than the spun mats. The foam structure is less dense (cheaper to produce and having less degradation products). The material remained in situ despite clinical wound infection. Proof of concept was achieved in both treatment modalities in the main study. Split skin graft applied immediately over the polymer foam was able to engraft successfully. The result was "thicker" to pinch and "flush" with the skin surrounding the wound. There was no significant difference in the degree of wound contraction between the graft alone and the polymer plus immediate graft groups. Split skin graft also "took" when applied to the surface of a polymer that had been applied to a wound 11 days earlier, again with a thicker result, flush with the surrounding skin. Split skin grafts alone left a persisting depression. However, a significant degree of wound contraction (compared with the other two groups) was observed in the polymer plus delayed graft group. This has prompted further investigation into "sealing" the polymer foam with a membrane, to prevent evaporative water loss, when the foam is to be used as a biodegradable temporizing matrix. The studies indicate that the Novo

  10. Delayed Union of a Sacral Fracture: Percutaneous Navigated Autologous Cancellous Bone Grafting and Screw Fixation

    SciTech Connect

    Huegli, R. W. Messmer, P.; Jacob, A. L.; Regazzoni, P.; Styger, S.; Gross, T.

    2003-09-15

    Delayed or non-union of a sacral fracture is a serious clinical condition that may include chronic pain, sitting discomfort, gait disturbances, neurological problems, and inability to work. It is also a difficult reconstruction problem. Late correction of the deformity is technically more demanding than the primary treatment of acute pelvic injuries. Open reduction, internal fixation (ORIF), excision of scar tissue, and bone grafting often in a multi-step approach are considered to be the treatment of choice in delayed unions of the pelvic ring. This procedure implies the risk of neurological and vascular injuries, infection, repeated failure of union, incomplete correction of the deformity, and incomplete pain relief as the most important complications. We report a new approach for minimally invasive treatment of a delayed union of the sacrum without vertical displacement. A patient who suffered a Malgaigne fracture (Tile C1.3) was initially treated with closed reduction and percutaneous screw fixation (CRPF) of the posterior pelvic ring under CT navigation and plating of the anterior pelvic ring. Three months after surgery he presented with increasing hip pain caused by a delayed union of the sacral fracture. The lesion was successfully treated percutaneously in a single step procedure using CT navigation for drilling of the delayed union, autologous bone grafting, and screw fixation.

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

    SciTech Connect

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

    2011-01-01

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

  12. Functional characterization of linear delay Langevin equations

    NASA Astrophysics Data System (ADS)

    Budini, Adrián A.; Cáceres, Manuel O.

    2004-10-01

    We present an exact functional characterization of linear delay Langevin equations driven by any noise structure defined through its characteristic functional. This method relies on the possibility of finding an explicitly analytical expression for each realization of the delayed stochastic process in terms of those of the driving noise. General properties of the transient dissipative dynamics are analyzed. The corresponding interplay with a color Gaussian noise is presented. As a full application of our functional method we study a model for population growth with non-Gaussian fluctuations: the Gompertz model driven by multiplicative white shot noise.

  13. Alveolar ridge preservation with deproteinized bovine bone graft and collagen membrane and delayed implants.

    PubMed

    Pang, Chaoyuan; Ding, Yuxiang; Zhou, Hongzhi; Qin, Ruifeng; Hou, Rui; Zhang, Guoliang; Hu, Kaijin

    2014-09-01

    To evaluate clinically and radiographically an alveolar ridge, preservation technique with deproteinized bovine bone graft and absorbable collagen membrane and then restoration with delayed implants were done. The study included 30 patients. The trial group's sockets were filled with deproteinized bovine bone graft (Bio-Oss) and covered with absorbable collagen membrane (Bio-Gide). The control group's sockets healed without any treatment. Panoramic radiograph and computed tomography were taken immediately after graft and 3 and 6 months later to evaluate the height, width, and volume change of the alveolar ridge bone. Dental implants were inserted in all sockets at 6 months, and osseointegration condition was evaluated in the following 12 months. All sockets healed uneventfully. In the trial group, the mean (SD) height reduction of the alveolar ridge bone was 1.05 (0.24) mm at 3 months and 1.54 (0.25) mm at 6 months. The width reduction was 1.11 (0.13) mm at 3 months and 1.84 (0.35) mm at 6 months. Bone volume reduction was 193.79 (21.47) mm at 3 months and 262.06 (33.08) mm at 6 months. At the same trend, in the control group, the bone height reduction was 2.12 (0.15) mm at 3 months and 3.26 (0.29) mm at 6 months. The width reduction was 2.72 (0.19) mm at 3 months and 3.56 (0.28) mm at 6 months. Bone volume reduction was 252.19 (37.21) mm at 3 months and 342.32 (36.41) mm at 6 months. There was a significant difference in alveolar ridge bone height, width, and volume reduction in the 2 groups. The osseointegration condition had no significant difference between the 2 groups. This study suggested that the deproteinized bovine bone graft and absorbable collagen membrane were beneficial to preserve the alveolar ridge bone and had no influence on the osseointegration of delayed implant.

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

    PubMed

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

    2016-03-01

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

  15. A continuous infusion of a minor histocompatibility antigen-immunodominant peptide induces a delay of male skin graft rejection.

    PubMed

    Sireci, Guido; Barera, Annalisa; Macaluso, Pasquale; Di Sano, Caterina; Bonanno, Cesira T; Pio La Manna, Marco; Di Liberto, Diana; Dieli, Francesco; Salerno, Alfredo

    2009-01-01

    We previously reported that an inhibition of antigen-specific Interferon-gamma release and cytotoxicity occurs after a continuous infusion of an HY immunodominant peptide although this treatment is not able to cause a significant delay of male skin grafts rejection. In vivo administration of high doses of an HY peptide, through mini-osmotic pumps, in naïve female mice was used to study the effects on the male skin grafts rejection. A continuous infusion of 1mg of an HY peptide induces a significant delay of male skin graft rejection. In vitro HY-specific Interferon-gamma release was inhibited adding peptide-specific suppressor cells: the ability to inhibit Interferon-gamma release was evident when two HY peptides were present on the same dendritic cells indicating that the suppressor cells exert "linked-suppression". The phenotype of the suppressor cells is CD8(+)CD28(-) and these cells express more CD62 ligand and FOXP3 than controls. Suppressor cells were able to cause a significant delay of rejection of male skin grafts when injected in naive female mice. The inhibitory effects of these suppressor cells seem to be due to the impairment of antigen presentation; down-regulation of B7 molecules on dendritic cells occurred. Taken all together, our data demonstrate that a continuous infusion of an immunodominant HY peptide induces a T CD8 suppressor subset able to inhibit immune responses to male tissues and cells.

  16. Facilitating tolerance of delayed reinforcement during functional communication training.

    PubMed

    Fisher, W W; Thompson, R H; Hagopian, L P; Bowman, L G; Krug, A

    2000-01-01

    Few clinical investigations have addressed the problem of delayed reinforcement. In this investigation, three individuals whose destructive behavior was maintained by positive reinforcement were treated using functional communication training (FCT) with extinction (EXT). Next, procedures used in the basic literature on delayed reinforcement and self-control (reinforcer delay fading, punishment of impulsive responding, and provision of an alternative activity during reinforcer delay) were used to teach participants to tolerate delayed reinforcement. With the first case, reinforcer delay fading alone was effective at maintaining low rates of destructive behavior while introducing delayed reinforcement. In the second case, the addition of a punishment component reduced destructive behavior to near-zero levels and facilitated reinforcer delay fading. With the third case, reinforcer delay fading was associated with increases in masturbation and head rolling, but prompting and praising the individual for completing work during the delay interval reduced all problem behaviors and facilitated reinforcer delay fading.

  17. Durable Nanolayer Graft Polymerization of Functional Finishes Using Atmospheric Plasma

    NASA Astrophysics Data System (ADS)

    Mazloumpour, Maryam

    Various applications of atmospheric pressure plasma were investigated in conjunction with different chemistries on nonwoven materials including spunbond polyester (PET) and spunbod polypropylene for fuel separation and antimicrobial functionalities. Hydrophobic/Oleophobic properties were conferred on nonwoven polyester (PET) via plasma-induced graft polymerization of different hydrophobic non-C8 perfluorocarbon chemistry including perfluorohexylethylmethacrylate, perfluorohexylethylacrylate, allylpentafluorobenzene, pentafluorostyrene, or 1,3-divinyltetramethyldisiloxane in the vapor form using both in-situ and down-stream plasma configurations. Different nanolayers of the grafted polymer were furnished on nonwovens to generate surfaces with different level of wettabilities for medical applications and water/fuel separation. The effect of various hydrophobic chemistry, different plasma conditions, and plasma device parameters including plasma power and plasma exposure time were studied and the performance was characterized by measuring the contact angle and the wettability rating against liquids with broad range of surface tensions. Vapor deposition of 2-(perfluorohexyl)ethyl methacrylate and pentafluorostyrene on nonwoven PET followed by plasma-induced graft polymerization was investigated for possible use in water/fuel separation. Different nanolayer thicknesses (80-180nm) of the grafted polymer were achieved to generate surfaces with different wettabilities for water/fuel separation of different fuel compositions. The effect of different plasma conditions and device parameters including the flow rate of monomers, power of the device, and time of plasma exposure on the separation of different fuels was studied and characterized by measuring the surface energy of the treated substrates. The surface chemistry and morphology of the treated samples were characterized using XPS, SEM and TOF-SIMS techniques which confirmed the grafting of monomer onto the substrate

  18. Calcification of Cryopreserved Arterial Graft Causing Delayed Obstruction of Portal Vein Flow After Liver Transplant.

    PubMed

    Cimsit, Bayindir; Yankol, Yucel; Mecit, Nesimi; Kanmaz, Turan; Acarli, Koray; Kalayoglu, Munci

    2015-10-01

    In patients with biliary atresia, portal vein problems may cause challenges for liver transplant. Interposition grafts have been used for vascular anastomoses in transplant recipients with varied success. A cryopreserved iliac artery graft was used for the reconstruction of the portal vein in a 29-month-old infant with biliary atresia. At 17 months after transplant, she developed upper gastrointestinal bleeding that was caused by portal vein occlusion because of vascular calcifications in the graft. Upper gastrointestinal endoscopy showed esophageal varices with fresh bleeding, and the varices were band ligated. At 3 months after the bleeding episode, the patient was asymptomatic and biochemical tests were normal. In summary, liver transplant with cryopreserved iliac artery graft may be complicated by calcifications and portal vein occlusion, and caution is advised in using this graft material for portal vein anastomoses.

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

    PubMed

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

    2017-04-01

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

  20. Value of thallium-201 reinjection after delayed SPECT imaging for predicting reversible ischemia after coronary artery bypass grafting

    SciTech Connect

    Ohtani, H.; Tamaki, N.; Yonekura, Y.; Mohiuddin, I.H.; Hirata, K.; Ban, T.; Konishi, J. )

    1990-08-15

    The reinjection of a small dose (40 MBq) of thallium-201 after stress and delayed imaging often shows new redistribution in the regions with persistent defect. To assess whether these segments may represent reversible ischemia, reinjection thallium-201 single-photon emission computed tomography (SPECT) was performed after stress and 3-hour delayed imaging in 24 patients before coronary artery bypass grafting (CABG). The left ventricular myocardium was divided into 5 myocardial segments and regional wall motion was scored on a scale from 0 (normal) to 4 (dyskinesia). Thallium-201 findings were compared with improvement in regional perfusion and wall motion 1 to 2 months after CABG. The reinjection imaging identified new redistribution in 15 of 32 persistent defects (47%) on the 3-hour delayed images. In the study of stress and delayed SPECT imaging, the improvement in perfusion was observed in 34 of 43 segments (79%) exhibiting redistribution and 15 of 32 (47%) segments without redistribution (p less than 0.01). The reinjection SPECT identified new redistribution in 12 of the 15 improved segments that were not detected on the delayed images. Similarly, the improvement in wall motion was observed in 23 of 31 segments (74%) exhibiting redistribution and 14 of 30 segments (47%) without redistribution on the delayed images (p less than 0.05). The reinjection identified new redistribution in 10 of the 14 improved segments that were undetected on the delayed images. The predictive values for improvement in perfusion and wall motion by the reinjection imaging were significantly higher (92 and 89%) than those by the delayed imaging (69 and 62%, respectively, p less than 0.05 each).

  1. Analysis of Functions of Delayed Echolalia in Autistic Children.

    ERIC Educational Resources Information Center

    Prizant, Barry M.; Rydell, Patrick J.

    1984-01-01

    Fourteen functional categories of delayed echolalia in three autistic children (4-14 years old) were derived from videotape analyses. Individual differences in functional usage were apparent across Ss. Delayed echolalia varied along the dimensions of interactiveness, comprehension of the utterance produced, and relevance to linguistic or…

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  3. Analysis of functions of delayed echolalia in autistic children.

    PubMed

    Prizant, B M; Rydell, P J

    1984-06-01

    This study was a preliminary attempt to determine how autistic children used delayed echolalia in naturalistic interactions with familiar people. Fourteen functional categories of delayed echolalia were derived based on videotape analyses of linguistic, extralinguistic, and paralinguistic features. Individual differences in functional usage were apparent across the three subjects. Delayed echolalia was found to vary along the dimensions of interactiveness, comprehension of the utterance produced, and relevance to linguistic or situational context. The diversity of delayed echolalic behavior is discussed in reference to its conventionality, the presence or absence of communicative intent, and its status as symbolic communicative activity.

  4. Anti-Donor HLA Antibody Response After Pancreatic Islet Grafting: Characteristics, Risk Factors, and Impact on Graft Function.

    PubMed

    Pouliquen, E; Baltzinger, P; Lemle, A; Chen, C-C; Parissiadis, A; Borot, S; Frimat, L; Girerd, S; Berney, T; Lablanche, S; Benhamou, P Y; Morelon, E; Badet, L; Dubois, V; Kessler, L; Thaunat, O

    2017-02-01

    Pancreatic islet grafting restores endogenous insulin production in type 1 diabetic patients, but long-term outcomes remain disappointing as a result of immunological destruction of allogeneic islets. In solid organ transplantation, donor-specific anti-HLA antibodies (DSA) are the first cause of organ failure. This retrospective multicentric study aimed at providing in-depth characterization of DSA response after pancreatic islet grafting, identifying the risk factor for DSA generation and determining the impact of DSA on graft function. Forty-two pancreatic islet graft recipients from the Groupe Rhin-Rhône-Alpes-Genève pour la Greffe d'Ilots de Langerhans consortium were enrolled. Pre- and postgrafting sera were screened for the presence of DSA and their ability to activate complement. Prevalence of DSA was 25% at 3 years postgrafting. The risk of sensitization increased steeply after immunosuppressive drug withdrawal. DSA repertoire diversity correlated with the number of HLA and eplet mismatches. DSA titer was significantly lower from that observed in solid organ transplantation. No detected DSA bound the complement fraction C3d. Finally, in contrast with solid organ transplantation, DSA did not seem to negatively affect pancreatic islet graft survival. This might be due to the low DSA titers, specific features of IgG limiting their ability to activate the complement and/or the lack of allogenic endothelial targets in pancreatic islet grafts.

  5. Enhanced Performance & Functionality of Tunable Delay Lines

    DTIC Science & Technology

    2012-08-01

    Multiplexer MZM Mach-Zehnder modulator ODL Optical delay line OFDM Orthogonal frequency division multiplexing OOK On-off keying OSNR Optical ...1565 nm in steps of 2 nm. A pulse width of ~1.2 ps was obtained for each channel . Shown in Figure 72 (b) is the optical spectrum after the XPM- based ...200 GHz channels . Optical sampling enables multicasting via supercontinuum from an NRZ signal (at a variable wavelength) and pulse compression further

  6. Thyroid gland function during the systemic graft versus host reaction

    SciTech Connect

    Kozlova, T.D.; Fedorov, G.N.; Molotkov, O.V.

    1986-04-01

    The aims of the present investigation were as follows: to determine the level of thyroid hormones and thyrotrophin (TSH) at various times after induction of graft versus host reaction (GVHR); to study the degree of /sup 125/ I uptake by thyroid gland tissue at the same times of the GVHR, and to determine correlation between the hormone levels and weight of the gland in the animals and also the body weight of the recipients. Serum levels of tri-iodothyronine (T/sub 3/), thyroxine (T/sub 4/), and TSH were determined by radioimmunoassay. /sup 125/ /SUB I/ was injected intraperitoneally in a dose of 3-4 microCi/100 g body weight. During the development of a systemic GVHR marked inhibition of thyroid function was discovered.

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

    PubMed Central

    Gassner, Holger G.

    2011-01-01

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

  8. The Therapeutic Effectiveness of Delayed Fetal Spinal Cord Tissue Transplantation on Respiratory Function Following Mid-Cervical Spinal Cord Injury.

    PubMed

    Lin, Chia-Ching; Lai, Sih-Rong; Shao, Yu-Han; Chen, Chun-Lin; Lee, Kun-Ze

    2017-01-17

    Respiratory impairment due to damage of the spinal respiratory motoneurons and interruption of the descending drives from brainstem premotor neurons to spinal respiratory motoneurons is the leading cause of morbidity and mortality following cervical spinal cord injury. The present study was designed to evaluate the therapeutic effectiveness of delayed transplantation of fetal spinal cord (FSC) tissue on respiratory function in rats with mid-cervical spinal cord injury. Embryonic day-14 rat FSC tissue was transplanted into a C4 spinal cord hemilesion cavity in adult male rats at 1 week postinjury. The histological results showed that FSC-derived grafts can survive, fill the lesion cavity, and differentiate into neurons and astrocytes at 8 weeks post-transplantation. Some FSC-derived graft neurons exhibited specific neurochemical markers of neurotransmitter (e.g., serotonin, noradrenalin, or acetylcholine). Moreover, a robust expression of glutamatergic and γ-aminobutyric acid-ergic fibers was observed within FSC-derived grafts. Retrograde tracing results indicated that there was a connection between FSC-derived grafts and host phrenic nucleus. Neurophysiological recording of the phrenic nerve demonstrated that phrenic burst amplitude ipsilateral to the lesion was significantly greater in injured animals that received FSC transplantation than in those that received buffer transplantation under high respiratory drives. These results suggest that delayed FSC transplantation may have the potential to repair the injured spinal cord and promote respiratory functional recovery after mid-cervical spinal cord injury.

  9. Modeling of GPS tropospheric delay wet Neill mapping function (NMF)

    NASA Astrophysics Data System (ADS)

    Sakidin, Hamzah; Ahmad, Asmala; Bugis, Ismadi

    2014-10-01

    The modeling of the GPS tropospheric delay mapping function should be revised by modifying or simplify its mathematical model. Some current mapping functions models are separated into hydrostatic and the wet part. The current tropospheric delay models use mapping functions in the form of continued fractions. This model is quite complex and need to be simplified. By using regression method, the wet mapping function models has been selected to be simplified. There are eleven operations for wet mapping function component of Neill Mapping Function (NMF), to be carried out before getting the mapping function scale factor. So, there is a need to simplify the mapping function models to allow faster calculation and also better understanding of the models.

  10. Generating functionals and Gaussian approximations for interruptible delay reactions

    NASA Astrophysics Data System (ADS)

    Brett, Tobias; Galla, Tobias

    2015-10-01

    We develop a generating functional description of the dynamics of non-Markovian individual-based systems in which delay reactions can be terminated before completion. This generalizes previous work in which a path-integral approach was applied to dynamics in which delay reactions complete with certainty. We construct a more widely applicable theory, and from it we derive Gaussian approximations of the dynamics, valid in the limit of large, but finite, population sizes. As an application of our theory we study predator-prey models with delay dynamics due to gestation or lag periods to reach the reproductive age. In particular, we focus on the effects of delay on noise-induced cycles.

  11. Delay in admission for elective coronary-artery bypass grafting is associated with increased in-hospital mortality

    PubMed Central

    Sobolev, Boris G; Fradet, Guy; Hayden, Robert; Kuramoto, Lisa; Levy, Adrian R; FitzGerald, Mark J

    2008-01-01

    Background Many health care systems now use priority wait lists for scheduling elective coronary artery bypass grafting (CABG) surgery, but there have not yet been any direct estimates of reductions in in-hospital mortality rate afforded by ensuring that the operation is performed within recommended time periods. Methods We used a population-based registry to identify patients with established coronary artery disease who underwent isolated CABG in British Columbia, Canada. We studied whether postoperative survival during hospital admission for CABG differed significantly among patients who waited for surgery longer than the recommended time, 6 weeks for patients needing semi-urgent surgery and 12 weeks for those needing non-urgent surgery. Results Among 7316 patients who underwent CABG, 97 died during the same hospital admission, for a province-wide death rate at discharge of 1.3%. The observed proportion of patients who died during the same admission was 1.0% (27 deaths among 2675 patients) for patients treated within the recommended time and 1.5% (70 among 4641) for whom CABG was delayed. After adjustment for age, sex, anatomy, comorbidity, calendar period, hospital, and mode of admission, patients with early CABG were only 2/3 as likely as those for whom CABG was delayed to experience in-hospital death (odds ratio 0.61; 95% confidence interval [CI] 0.39 to 0.96). There was a linear trend of 5% increase in the odds of in-hospital death for every additional month of delay before surgery, adjusted OR = 1.05 (95% CI 1.00 to 1.11). Conclusion We found a significant survival benefit from performing surgical revascularization within the time deemed acceptable to consultant surgeons for patients requiring the treatment on a semi-urgent or non-urgent basis. PMID:18803823

  12. Surface-grafting of phosphates onto a polymer for potential biomimetic functionalization of biomaterials

    PubMed Central

    Ko, Young Gun; Ma, Peter X.

    2009-01-01

    In the human body, phosphate groups play important roles in signaling and the biological functions of proteins and peptides. Despite the importance of phosphate groups, polymer surfaces have not been directly grafted with phosphate groups by chemical reactions because the usual organic solvents used to graft phosphate groups can dissolve or swell polymers. We focused this study on grafting phosphate groups onto a poly(ethylene-co-acrylic acid) (PEAA) surface in an aqueous solution. O-phospho L-serine and O-phosphoethanolamine were grafted on PEAA surfaces to introduce phosphate groups by activating carboxylic acid groups of PEAA using N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) in an aqueous environment. X-ray photoelectron spectroscopy (XPS) was used to elucidate the process by which surface grafting occurs and the process that the phosphate group is cleaved into a phosphate ion and a hydrolyzed molecule at high pH. It was found that under appropriate reaction conditions the phosphate groups could be successfully grafted on the polymer surfaces. The phosphate-grafted polymer surfaces showed lower water contact angles than the initial polymer surfaces likely due to their highly mobile and hydrophilic phosphate-chains. This work demonstrates a technique to successfully graft phosphate groups onto organic polymer surfaces in a biocompatible aqueous environment, which may open new avenues to functionalizing synthetic polymeric and natural macromolecule derived biomaterials. PMID:18977490

  13. Facilitating Tolerance of Delayed Reinforcement during Functional Communication Training.

    ERIC Educational Resources Information Center

    Fisher, Wayne W.; Thompson, Rachel H.; Hagopian, Louis P.; Bowman, Lynn G.; Krug, Amy

    2000-01-01

    Three individuals with severe behavior disorders and mental retardation, whose destructive behaviors were being maintained by positive reinforcement, were treated using functional communication training with extinction. The case studies investigated techniques used to increase effectiveness of delayed reinforcement and to teach individuals with…

  14. Effects of variable training, signaled and unsignaled delays, and d-amphetamine on delay-discounting functions.

    PubMed

    Slezak, Jonathan M; Anderson, Karen G

    2009-09-01

    One common procedure for obtaining delay-discounting functions consists of a choice between a larger reinforcer that is presented after an increasing delay and a smaller reinforcer that is always presented immediately within session. Repeating the same context of delay presentation (e.g. ascending delay order) in a discrete-choice paradigm, however, may lead to a perseverative response pattern when rats are used as subjects. The purpose of this study was to increase the variability in delay presentation (i.e. ascending and descending delays) in an attempt to reduce a perseverative response pattern and gain tighter control over choice by reinforcer amount and delay. For one group of rats (n = 8), delays to reinforcer presentation were differentially signaled by a flashing houselight and for one group of rats (n = 8) the delays were unsignaled. Effects of delay signal and d-amphetamine on choice were evaluated in both groups. Similar rates of delay discounting and area under the curve (AUC) were observed with both ascending and descending delay presentations and with signaled and unsignaled delays to reinforcement. Increasing the variability in delay order resulted in differences in the choice pattern during 0-s probe sessions. d-Amphetamine had little or no effect on AUC at low doses, but decreased AUC at the highest doses tested, that is, 1.0 and 1.7 mg/kg. Some of the changes in AUC after d-amphetamine administration may have been because of disruption in discrimination of the different food amounts.

  15. Surface modification of ultrafiltration membranes by grafting glycine-functionalized PVA based on polydopamine coatings

    NASA Astrophysics Data System (ADS)

    Li, Fang; Ye, Jianfeng; Yang, Linming; Deng, Chunhua; Tian, Qing; Yang, Bo

    2015-08-01

    Due to the ease of processing and stability during filtration, polydopamine (PD) coatings with grafted hydrophilic polymers have recently received significant attention. In this study, glycine-functionalized PVA was synthesized and grafted to a PD-coated ultrafiltration (UF) membrane to improve its performance during wastewater filtration. The membranes were modified by grafting PD with glycine-functionalized PVA (PD-g-PVA), and the resultant materials were characterized using surface morphology analyses, contact angle measurements, flux, oil/water emulsion separation tests, and grafted layer stability tests. The performance of the PD-g-PVA membrane was compared to that of the membrane modified with PD-g-polyethylene glycol (PEG). After grafting the PD-g-PVA, the surface roughness of the membranes decreased significantly. The grafted PVA layer, which was stable under acidic and alkaline conditions, protected the PD layer. The filtration experiments with an oil/water emulsion indicated that modifying the glycine-functionalized PVA by grafting can significantly improve the antifouling ability of membranes.

  16. 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.

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

    PubMed Central

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

    2016-01-01

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

  18. 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

  19. Delayed Development of Brain Abscesses Following Stent-Graft Placement in a Head and Neck Cancer Patient Presenting with Carotid Blowout Syndrome

    SciTech Connect

    Oweis, Yaseen; Gemmete, Joseph J. Chaudhary, Neeraj; Pandey, Aditya; Ansari, Sameer

    2011-02-15

    We describe the delayed development of intracranial abscesses following emergent treatment with a covered stent-graft for carotid blowout syndrome (CBS) in a patient with head and neck cancer. The patient presented with hemoptysis and frank arterial bleeding through the tracheostomy site. A self-expandable stent-graft was deployed across a small pseudoaneurysm arising from the right common carotid artery (RCCA) and resulted in immediate hemostasis. Three months later, the patient suffered a recurrent hemorrhage. CT of the neck demonstrated periluminal fluid around the caudal aspect of the stent-graft with intraluminal thrombus and a small pseudoaneurysm. Subsequently, the patient underwent a balloon test occlusion study and endovascular sacrifice of the RCCA and right internal carotid artery. MRI of the brain demonstrated at least four ring-enhancing lesions within the right cerebral hemisphere consistent with intracranial abscesses that resolved with broad-spectrum antibiotic coverage.

  20. A novel control design for delayed teleoperation based on delay-scheduled Lyapunov-Krasovskii functionals

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Kruszewski, Alexandre; Richard, Jean-Pierre

    2014-08-01

    This paper addresses the controller design problem for bilateral teleoperation over unreliable networks. The stability and tracking performance analyses are presented for a novel force-reflecting emulator control scheme. The performance (stability, synchronisation, transparency) is guaranteed by H∞ control theory and delay-scheduled Lyapunov-Krasovskii functionals (LKF), which could improve the existing stability criterion. The design is achieved by using linear matrix inequality optimisation. For the simulation, first, numerical examples are given to demonstrate the effectiveness and benefits of the delay-scheduled LKF-based stability results; second, the proposed controller design solution is illustrated by various simulations and compared with other recent approaches under different working conditions, e.g. abrupt tracking motion and wall contact.

  1. Influence of phosphate-buffered sucrose solution on early graft function in feline renal autotransplantation.

    PubMed

    Katayama, Masaaki; Okamura, Yasuhiko; Shimamura, Shunsuke; Katayama, Rieko; Kamishina, Hiroaki; Uzuka, Yuji

    2014-10-01

    Graft perfusion with cold heparinized saline has known to induce ischemia and reperfusion injury in feline kidney transplantation. In this study, the effects of phosphate-buffered sucrose solution and heparinized saline solution on early kidney graft function were compared in feline kidney autotransplantation. Perfusion of grafts with or without hypothermic storage with chilled phosphate-buffered sucrose solution prevented ischemia and reperfusion injury despite a very short ischemic time. The results of our study suggest that phosphate-buffered sucrose perfusion and storage solution should be effective to reduce ischemia and reperfusion injury despite a very short ischemic time in feline kidney transplantation.

  2. Posttransplantation quality of life: more than graft function.

    PubMed

    Habwe, Violet Q

    2006-04-01

    Whereas newer immunosuppressive therapies have increased patient and graft survival, long-term treatment with these drugs has been linked to medical and physical complications that may impact on posttransplantation quality of life. Immunosuppression-related physical side effects that can alter appearance--including hirsutism, gingival hyperplasia, weight gain, cushingoid facies, hand tremors, alopecia, and skin disorders--are among the most bothersome to patients and may have serious psychosocial implications. In addition, physical side effects may influence patient adherence to their prescribed treatment regimens and result in more serious complications, such as acute rejection, graft loss, rehospitalization, and even mortality. Therefore, strategies for minimizing side effects of immunosuppressive therapy and improving medication adherence are integral to better long-term transplant recipient management.

  3. Controller design for TS models using delayed nonquadratic Lyapunov functions.

    PubMed

    Lendek, Zsofia; Guerra, Thierry-Marie; Lauber, Jimmy

    2015-03-01

    In the last few years, nonquadratic Lyapunov functions have been more and more frequently used in the analysis and controller design for Takagi-Sugeno fuzzy models. In this paper, we developed relaxed conditions for controller design using nonquadratic Lyapunov functions and delayed controllers and give a general framework for the use of such Lyapunov functions. The two controller design methods developed in this framework outperform and generalize current state-of-the-art methods. The proposed methods are extended to robust and H∞ control and α -sample variation.

  4. Hydrophobic surface functionalization of lignocellulosic jute fabrics by enzymatic grafting of octadecylamine.

    PubMed

    Dong, Aixue; Fan, Xuerong; Wang, Qiang; Yu, Yuanyuan; Cavaco-Paulo, Artur

    2015-08-01

    Enzymatic grafting of synthetic molecules onto lignins provides a mild and eco-friendly alternative for the functionalization of lignocellulosic materials. In this study, laccase-mediated grafting of octadecylamine (OA) onto lignin-rich jute fabrics was investigated for enhancing the surface hydrophobicity. First, the lignins in jute fabrics were isolated and analyzed in the macromolecular level by MALDI-TOF MS, (1)H NMR, (13)C NMR, and HSQC-NMR. Then, the surface of jute fabrics was characterized by FT-IR, XPS, and SEM. Subsequently, the nitrogen content of jute fabrics was determined by the micro-Kjeldahl method, and the grafting percentage (Gp) and grafting efficiency (GE) of the enzymatic reaction were calculated. Finally, the surface hydrophobicity of the jute fabrics was estimated by contact angle and wetting time measurements. The results indicate that the OA monomers were successfully grafted onto the lignin moieties on the jute fiber surface by laccase with Gp and GE values of 0.712% and 10.571%, respectively. Moreover, the modified jute fabrics via OA-grafting showed an increased wetting time of 18.5 min and a contact angle of 116.72°, indicating that the surface hydrophobicity of the jute fabrics increased after the enzymatic grafting modification with hydrophobic OA molecules.

  5. Impact of HLA mismatch at first kidney transplant on lifetime with graft function in young recipients.

    PubMed

    Foster, B J; Dahhou, M; Zhang, X; Platt, R W; Smith, J M; Hanley, J A

    2014-04-01

    As HLA matching has been progressively de-emphasized in the American deceased donor (DD) kidney allocation algorithm, concerns have been raised that poor matching at first transplant may lead to greater sensitization and more difficulty finding an acceptable donor for a second transplant should the first transplant fail. We compared proportion of total observed lifetime with graft function after first transplant, and waiting times for a second transplant between individuals with different levels of HLA mismatch (MM) at first transplant. We studied patients recorded in the United States Renal Data System (1988-2009) who received a first DD transplant at age ≤21 years (n = 8433), and the subgroup who were listed for a second DD transplant following first graft failure (n = 2498). Compared with recipients of 2-3 MM first grafts, 4-6 MM graft recipients spent 12% less of their time and 0-1 MM recipients 15% more time with a functioning graft after the first transplant (both p < 0.0001); 4-6 MM recipients were significantly less likely (hazard ratio [HR] 0.87 [95% confidence interval 0.76, 0.98]; p = 0.03), and 0-1 MM recipients more likely (HR 1.26 [0.99, 1.60]; p = 0.06) to receive a second transplant after listing. The benefits of better HLA matching at first transplant on lifetime with graft function are significant, but relatively small.

  6. 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.

  7. Replicator dynamics with alternate growth functions, delay, and quasiperiodic forcing

    NASA Astrophysics Data System (ADS)

    Wesson, Elizabeth Nicholas

    Evolutionary dynamics combines game theory and nonlinear dynamics to model competition in biological and social situations. The replicator equation is a standard paradigm in evolutionary dynamics. The growth rate of each strategy is its excess fitness: the deviation of its fitness from the average. The gametheoretic aspect of the model lies in the choice of fitness function, which is determined by a payoff matrix. Two well-known replicator systems are the threestrategy Rock-Paper-Scissors game and the two-strategy Hawk-Dove game. In this work, we analyze the dynamics of replicator systems with three different types of modifications. The first generalization of the replicator model is given by considering alternate growth functions. We find that in the Rock-Paper-Scissors game with a logistic growth function, there are several fixed points that do not exist in the standard replicator model. The system exhibits both periodic motion and convergence to attractors. We also analyze replicator systems with delayed interactions between strategies. We consider a symmetric delay model, in which the fitness of each strategy is its expected payoff delayed by a time interval; and an asymmetric model, in which same-strategy terms appearing in the fitness of a given strategy are not delayed. In both cases, limit cycles arise that cannot occur in the usual replicator model. Finally, we examine Rock-Paper-Scissors systems with quasiperiodic forcing of the payoff coefficients. This model may represent systems in which the competition is affected by cyclical processes on different time-scales. We find that the stability of the equilibrium state depends sensitively on the two forcing frequencies; in fact, the region of stability has fractal boundary.

  8. Impaired mitochondrial functions in organophosphate induced delayed neuropathy in rats.

    PubMed

    Masoud, Anwar; Kiran, Ravi; Sandhir, Rajat

    2009-12-01

    Acute exposure to organophosphates induces a delayed neurodegenerative condition known as organophosphate-induced delayed neuropathy (OPIDN). The mechanism of OPIDN has not been fully understood as it does not involve cholinergic crisis. The present study has been designed to evaluate the role of mitochondrial dysfunctions in the development of OPIDN. OPIDN was induced in rats by administering acute dose of monocrotophos (MCP, 20 mg/kg body weight, orally) or dichlorvos (DDVP, 200 mg/kg body weight, subcutaneously), 15-20 min after treatment with antidotes [atropine (20 mg/kg body weight) and 2-PAM (100 mg/kg body weight) intraperitoneally]. MDA levels were observed to be higher and thiol content was lower in mitochondria from brain regions of OP exposed animals. This was accompanied by decreased activities of the mitochondrial enzymes; NADH dehydrogenase, succinate dehydrogenase, and cytochrome oxidase. In addition, mitochondrial functions assessed by MTT reduction also confirmed mitochondrial dysfunctions following development of OPIDN. The spatial long-term memory evaluated using elevated plus-maze test was observed to be deficit in OPIDN. The results suggest impaired mitochondrial functions as a mechanism involved in the development of organophosphate induced delayed neuropathy.

  9. Neutrophil Gelatinase-Associated Lipocalin in Kidney Transplantation Is an Early Marker of Graft Dysfunction and Is Associated with One-Year Renal Function

    PubMed Central

    Fonseca, Isabel; Oliveira, José Carlos; Almeida, Manuela; Cruz, Madalena; Malho, Anabela; Martins, La Salete; Dias, Leonídio; Santos, Josefina; Lobato, Luísa; Castro Henriques, António; Mendonça, Denisa

    2013-01-01

    Urinary neutrophil gelatinase-associated lipocalin (uNGAL) has been suggested as potential early marker of delayed graft function (DGF) following kidney transplantation (KTx). We conducted a prospective study in 40 consecutive KTx recipients to evaluate serial changes of uNGAL within the first week after KTx and assess its performance in predicting DGF (dialysis requirement during initial posttransplant week) and graft function throughout first year. Urine samples were collected on post-KTx days 0, 1, 2, 4, and 7. Linear mixed and multivariable regression models, receiver-operating characteristic (ROC), and areas under ROC curves were used. At all-time points, mean uNGAL levels were significantly higher in patients developing DGF (n = 18). Shortly after KTx (3–6 h), uNGAL values were higher in DGF recipients (on average +242 ng/mL, considering mean dialysis time of 4.1 years) and rose further in following days, contrasting with prompt function recipients. Day-1 uNGAL levels accurately predicted DGF (AUC-ROC = 0.93), with a performance higher than serum creatinine (AUC-ROC = 0.76), and similar to cystatin C (AUC-ROC = 0.95). Multivariable analyses revealed that uNGAL levels at days 4 and 7 were strongly associated with one-year serum creatinine. Urinary NGAL is an early marker of graft injury and is independently associated with dialysis requirement within one week after KTx and one-year graft function. PMID:24288591

  10. Versatile Functionalization of Polysaccharides via Polymer Grafts: From Design to Biomedical Applications.

    PubMed

    Hu, Yang; Li, Yang; Xu, Fu-Jian

    2017-02-21

    Because of their biocompatibility, biodegradability, and unique bioactive properties, polysaccharides have been recognized and directly applied as excellent candidates for various biomedical applications. In order to introduce more functionalities onto polysaccharides, various modification methods were applied to improve the physical-chemical and biochemical properties. Grafting polysaccharides with functional polymers with limited reaction sites maximizes the structural integrity. To the best of our knowledge, great efforts have been made by scientists across the world, including our research group, to explore different strategies for the synthesis and design of controllable polymer-grafted polysaccharides. By the application of some reasonable strategies, a series of polymer-grafted polysaccharides with satisfactory biocharacteristics were obtained. The first strategy involves facile modification of polysaccharides with living radical polymerization (LRP). Functionalized polysaccharides with diverse grafts can be flexibly and effectively achieved. The introduced grafts include cationic components for nuclei acid delivery, PEGylated and zwitterionic moieties for shielding effects, and functional species for bioimaging applications as well as bioresponsive drug release applications. The second synthetic model refers to biodegradable polymer-grafted polysaccharides prepared by ring-opening polymerization (ROP). Inspired by pathways to introduce initiation sites onto polysaccharides, the use of amine-functionalized polysaccharides was explored in-depth to trigger ROP of amino acids. A series of poly(amino acid)-grafted polysaccharides with advanced structures (including linear, star-shaped, and comb-shaped copolymers) were developed to study and optimize the structural effects. In addition, biodegradable polyester-grafted polysaccharides were prepared and utilized for drug delivery. Another emerging strategy was to design polysaccharide-based assemblies with

  11. Correlation between von Willebrand factor levels and early graft function in clinical liver transplantation.

    PubMed

    Basile, J; Busuttil, A; Sheiner, P A; Emre, S; Guy, S; Schwartz, M E; Boros, P; Miller, C M

    1999-02-01

    Cold preservation/reperfusion leads to sinusoidal endothelial cell (SEC) activation and damage in nearly every liver transplantation; the extent of these changes influences early graft function. Upon reperfusion, activated SEC show increased expression of adhesion molecules, including von Willebrand factor (vWF) which is released into the circulation. This study was designed to evaluate the levels of vWF measured in the caval effluent and correlate these findings with known markers of SEC damage and early graft function. Data were obtained from 35 patients undergoing orthotopic liver transplantation (LTx). Two samples were taken from each patient for measurement of vWF: a) from the portal vein immediately prior to reperfusion; and b) from the first 50 ml of the caval effluent. Commercial assays were used to measure vWF, as well as hyaluronic acid (HA), thrombomodulin (TM), IL-1 beta, IL-6, IL-8 and TNF-alpha. Patients were divided into two groups based on early graft function. Poor early graft function (PEGF) was defined as a peak aspartate transaminase (AST) or alanine transaminase (ALT) level > 2500 U/L during the first three postoperative days (POD) and a prothrombin time (PT) > 16 s on POD 2 (n = 8). The remaining 27 patients had good early graft function (GEGF). In patients with GEGF, vWF levels dropped significantly between the two time points. This change was not observed in those with PEGF. A positive linear correlation was observed in the PEGF group between vWF and HA and IL-6. The different pattern of change in vWF between the two groups, as well as the positive correlation between HA, IL-6 and vWF in PEGF, suggest that vWF may be a useful marker of early graft function.

  12. Grafting in confined spaces: Functionalization of nanochannels of track-etched membranes

    NASA Astrophysics Data System (ADS)

    Barsbay, Murat; Güven, Olgun

    2014-12-01

    Developments in the field of membrane science and specialty applications have given rise to track-etched membranes with nanochannels having broad ranges of functionality and versatile opportunities. This review is a compilation of the recent progress in methods and applications of grafting inside confined spaces in nanoscale. The emphasis has been made on functionalization of nanochannels of track-etched membranes. Selected current literature on track-etched membranes having nanochannels grafted with various polymers has been reviewed in terms of potential applications of the resulting membrane in the fields of biotechnology, energy and environment.

  13. Modular Small Diameter Vascular Grafts with Bioactive Functionalities

    PubMed Central

    Neufurth, Meik; Wang, Xiaohong; Tolba, Emad; Dorweiler, Bernhard; Schröder, Heinz C.; Link, Thorben; Diehl-Seifert, Bärbel; Müller, Werner E. G.

    2015-01-01

    We report the fabrication of a novel type of artificial small diameter blood vessels, termed biomimetic tissue-engineered blood vessels (bTEBV), with a modular composition. They are composed of a hydrogel scaffold consisting of two negatively charged natural polymers, alginate and a modified chitosan, N,O-carboxymethyl chitosan (N,O-CMC). Into this biologically inert scaffold two biofunctionally active biopolymers are embedded, inorganic polyphosphate (polyP) and silica, as well as gelatin which exposes the cell recognition signal, Arg-Gly-Asp (RGD). These materials can be hardened by exposure to Ca2+ through formation of Ca2+ bridges between the polyanions, alginate, N,O-CMC, and polyP (alginate-Ca2+-N,O-CMC-polyP). The bTEBV are formed by pressing the hydrogel through an extruder into a hardening solution, containing Ca2+. In this universal scaffold of the bTEBV biomaterial, polycations such as poly(l-Lys), poly(d-Lys) or a His/Gly-tagged RGD peptide (three RGD units) were incorporated, which promote the adhesion of endothelial cells to the vessel surface. The mechanical properties of the biopolymer material (alginate-Ca2+-N,O-CMC-polyP-silica) revealed a hardness (elastic modulus) of 475 kPa even after a short incubation period in CaCl2 solution. The material of the artificial vascular grafts (bTEBVs with an outer size 6 mm and 1.8 mm, and an inner diameter 4 mm and 0.8 mm, respectively) turned out to be durable in 4-week pulsatile flow experiments at an alternating pressure between 25 and 100 mbar (18.7 and 75.0 mm Hg). The burst pressure of the larger (smaller) vessels was 850 mbar (145 mbar). Incorporation of polycationic poly(l-Lys), poly(d-Lys), and especially the His/Gly-tagged RGD peptide, markedly increased the adhesion of human, umbilical vein/vascular endothelial cells, EA.HY926 cells, to the surface of the hydrogel. No significant effect of the polyP samples on the clotting of human plasma is measured. We propose that the metabolically degradable

  14. Using logistic regression to estimate delay-discounting functions.

    PubMed

    Wileyto, E Paul; Audrain-McGovern, Janet; Epstein, Leonard H; Lerman, Caryn

    2004-02-01

    The monetary choice questionnaire (MCQ) and similar computer tasks ask preference questions in order to ascertain indifference, the perceived equivalence of immediate versus larger delayed rewards. Indifference data are then fitted with a hyperbolic function, summarizing the decline in perceived value with delay time. We present a fitting method that estimates the hyperbolic parameter k directly from survey responses. Binary preferences are modeled as a function of time (X2) and a transformed reward ratio (X1), yielding logistic regression coefficients beta 2 and beta 1. The hyperbolic parameter emerges as k = beta 2/beta 1, where the logistic predicted p = .5 (the definition of indifference). The MCQ was administered to 1,073 adolescents and was scored using both standard and logistic methods. The means for In(k) were similar (standard, -4.53; logistic, -4.51), and the results were highly correlated (rho = .973). Simulated MCQ data showed that k was unbiased, except where beta 1 > or = -1, indicating a vague survey response. Jackknife standard errors provided excellent coverage.

  15. Functional and Aesthetic Recovery of Congenital Muscular Torticollis with Intramuscular Stromal Vascular Fraction Enriched Fat Grafting

    PubMed Central

    2017-01-01

    Congenital muscular torticollis is a well-known pathological condition caused by the contracture and shortening of the sternocleidomastoid muscle. This condition is manifested by a neck postural deformity often accompanied by some kind of facial asymmetry. Once diagnosed, treatment by early physiotherapy is generally successful in a high percentage of patients if performed during the first year of life. Later, especially after the fourth year, conservative treatment is usually far less effective, and surgical techniques remain the only way to improve neck contour and function. The author reports two cases of adult patients affected by this condition and successfully treated with a novel therapeutic approach consisting of percutaneous myotomies and intramuscular cell-assisted fat grafting. Two cases of adult patients diagnosed with congenital muscular torticollis were analyzed after treatment with percutaneous myotomies and intramuscular fat grafting. The first patient had a history of unsuccessful treatment in infancy with bipolar release of the sternocleidomastoid muscle and was treated with two sessions of fat grafting. The second patient had a history of neglected torticollis and was treated with a single session of cell-assisted fat grafting. In both cases, facial asymmetries were simultaneously treated with the same fat grafting protocol used to treat the muscle. Improvements in muscle function and in face and neck contours were extremely good and stable in both patients. The postoperative course for both patients was uneventful and with a very short and easy recovery when compared with the techniques described to date. Neglected congenital muscular torticollis in adults, or in patients who have not responded adequately to surgical treatment, has been treated safely with percutaneous myotomies and intramuscular fat grafting. The benefit is a scarless technique that provides simultaneous recovery of neck aesthetics and muscle function together with a very

  16. Functional and Aesthetic Recovery of Congenital Muscular Torticollis with Intramuscular Stromal Vascular Fraction Enriched Fat Grafting.

    PubMed

    Monreal, Juan

    2017-01-12

    Congenital muscular torticollis is a well-known pathological condition caused by the contracture and shortening of the sternocleidomastoid muscle. This condition is manifested by a neck postural deformity often accompanied by some kind of facial asymmetry. Once diagnosed, treatment by early physiotherapy is generally successful in a high percentage of patients if performed during the first year of life. Later, especially after the fourth year, conservative treatment is usually far less effective, and surgical techniques remain the only way to improve neck contour and function. The author reports two cases of adult patients affected by this condition and successfully treated with a novel therapeutic approach consisting of percutaneous myotomies and intramuscular cell-assisted fat grafting. Two cases of adult patients diagnosed with congenital muscular torticollis were analyzed after treatment with percutaneous myotomies and intramuscular fat grafting. The first patient had a history of unsuccessful treatment in infancy with bipolar release of the sternocleidomastoid muscle and was treated with two sessions of fat grafting. The second patient had a history of neglected torticollis and was treated with a single session of cell-assisted fat grafting. In both cases, facial asymmetries were simultaneously treated with the same fat grafting protocol used to treat the muscle. Improvements in muscle function and in face and neck contours were extremely good and stable in both patients. The postoperative course for both patients was uneventful and with a very short and easy recovery when compared with the techniques described to date. Neglected congenital muscular torticollis in adults, or in patients who have not responded adequately to surgical treatment, has been treated safely with percutaneous myotomies and intramuscular fat grafting. The benefit is a scarless technique that provides simultaneous recovery of neck aesthetics and muscle function together with a very

  17. Facile one-step catalytic grafting of N-hydroxysuccinimidyl-ester-functionalized methallylsilane onto silica for enzyme immobilization.

    PubMed

    Jung, Un-Young; Park, Jung-Woo; Han, Eun-Hee; Kang, Sin-Gun; Lee, Sera; Jun, Chul-Ho

    2011-02-01

    A one-step grafting method of NHS-ester group is described for the immobilization of enzymes onto a silica surface at room temperature. Pure NHS-ester functionalized methallylsilane was prepared as a grafting reagent and showed remarkable grafting efficiency with acid catalysts at room temperature. As a result, mesoporous silica balls bearing a covalently immobilized enzyme could be obtained with a high loading rate compared to conventional multistep grafting methods. This one-step procedure offers the advantages of precise measurement of the high loading efficiency of the NHS-ester group, and the exclusive formation of only the NHS-ester group, which reduces the presence of unreacted functionalities.

  18. Amine functionalization of cellulose surface grafted with glycidyl methacrylate by γ-initiated RAFT polymerization

    NASA Astrophysics Data System (ADS)

    Barsbay, Murat; Güven, Olgun; Kodama, Yasko

    2016-07-01

    This study presents the functionalization of poly(glycidyl methacrylate) (PGMA) grafted cellulose filter paper by a model compound, ethylenediamine (EDA), through the epoxy groups of PGMA. Cellulose based copolymers were prepared via the radiation-induced and RAFT-mediated graft polymerization. The samples were characterized by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis, contact angle measurements and scanning electron microscopy (SEM). An efficient modification density of around 1 mmol EDA/mg copolymer was attained within ca. 8 h, indicating that chemical composition of well-defined copolymers may further be tuned by appropriately selecting the reactive agents for use in many emerging fields.

  19. A density functional study on dielectric properties of acrylic acid grafted polypropylene.

    PubMed

    Ruuska, Henna; Arola, Eero; Kortelainen, Tommi; Rantala, Tapio T; Kannus, Kari; Valkealahti, Seppo

    2011-04-07

    Influence of acrylic acid grafting of isotactic polypropylene on the dielectric properties of the polymer is investigated using density functional theory (DFT) calculations, both in the molecular modeling and three-dimensional (3D) bulk periodic system frameworks. In our molecular modeling calculations, polarizability volume, and polarizability volume per mass which reflects the permittivity of the polymer, as well as the HOMO-LUMO gap, one of the important measures indicating the electrical breakdown voltage strength, were examined for oligomers with various chain lengths and carboxyl mixture ratios. When a polypropylene oligomer is grafted with carboxyl groups (cf. acrylic acid), our calculations show that the increase of the polarizability volume α' of the oligomer is proportional to the increase of its mass m, while the ratio α'/m decreases from the value of a pure polymer when increasing the mixture ratio. The decreasing ratio of α'/m under carboxyl grafting indicates that the material permittivity might also decrease if the mass density of the material remains constant. Furthermore, our calculations show that the HOMO-LUMO gap energy decreases by only about 15% in grafting, but this decrease seems to be independent on the mixture ratio of carboxyl. This indicates that by doping polymers with additives better dielectric properties can be tailored. Finally, using the first-principles molecular DFT results for polarizability volume per mass in connection with the classical Clausius-Mossotti relation, we have estimated static permittivity for acrylic acid grafted polypropylene, assuming the structural density keeping constant under grafting. The computed permittivity values are in a qualitative agreement with the recent experiments, showing increasing tendency of the permittivity as a function of the grafting composition. In order to validate our molecular DFT based approach, we have also carried out extensive three-dimensional bulk periodic first

  20. Click chemistry grafting of poly(ethylene glycol) brushes to alkyne-functionalized pseudobrushes.

    PubMed

    Ostaci, Roxana-Viorela; Damiron, Denis; Grohens, Yves; Léger, Liliane; Drockenmuller, Eric

    2010-01-19

    A versatile method for the grafting of azide-terminated polymer chains to alkyne-functionalized pseudobrushes by the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition has been developed. First, poly[(propargyl methacrylate)-r-(glycidyl methacrylate)-r-(methyl methacrylate)] random copolymers with monomer ratios of respectively 27/27/46, 41/31/28, and 45/55/0 were synthesized by RAFT polymerization. Then, dense alkyne-functionalized pseudobrushes were grafted in melt by thermal ring-opening of the glycidyl groups by the silanols from the silicon substrate. Finally, the grafting of tailor-made alpha-methoxy-omega-azido-poly(ethylene glycol)s (M(w) approximately 5000, 20,000, and 50,000 g/mol) by Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition was performed in sealed reactors at 60 degrees C for 72 h using a polymer weight fraction of 10% in tetrahydrofuran and Cu(PPh(3))(3)Br/DIPEA as the catalytic system. Alkyne-functionalized pseudobrushes and poly(ethylene glycol) brushes were characterized by ellipsometry, scanning probe microscopy, and water contact angle measurements. This "grafting-to" approach represents a fast and versatile method to provide thick and homogeneous polymer brushes with a high surface coverage. A major benefit of this strategy is the tunable and versatile tethering of alkyne functionalities to silicon substrates using a straightforward spin-coating procedure.

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

    PubMed

    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.

  2. 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

  3. The VLBI time delay function for synchronous orbits

    NASA Technical Reports Server (NTRS)

    Rosenbaum, B.

    1972-01-01

    The VLBI is a satellite tracking technique that to date was applied largely to the tracking of synchronous orbits. These orbits are favorable for VLBI in that the remote satellite range allows continuous viewing from widely separated stations. The primary observable, geometric time delay is the time difference for signal propagation between satellite and baseline terminals. Extraordinary accuracy in angular position data on the satellite can be obtained by observation from baselines of continental dimensions. In satellite tracking though the common objective is to derive orbital elements. A question arises as to how the baseline vector bears on the accuracy of determining the elements. Our approach to this question is to derive an analytic expression for the time delay function in terms of Kepler elements and station coordinates. The analysis, which is for simplicity based on elliptic motion, shows that the resolution for the inclination of the orbital plane depends on the magnitude of the baseline polar component and the resolution for in-plane elements depends on the magnitude of a projected equatorial baseline component.

  4. Ketoprofen combined with artery graft entubulization improves functional recovery of transected peripheral nerves.

    PubMed

    Mohammadi, Rahim; Mehrtash, Moein; Nikonam, Nima; Mehrtash, Moied; Amini, Keyvan

    2014-12-01

    The objective was to assess the local effect of ketoprofen on sciatic nerve regeneration and functional recovery. Eighty healthy male white Wistar rats were randomized into four experimental groups of 20 animals each: In the transected group (TC), the left sciatic nerve was transected and nerve cut ends were fixed in the adjacent muscle. In the treatment group the defect was bridged using an artery graft (AG/Keto) filled with 10 microliter ketoprofen (0.1 mg/kg). In the artery graft group (AG), the graft was filled with phosphated-buffer saline alone. In the sham-operated group (SHAM), the sciatic nerve was exposed and manipulated. Each group was subdivided into four subgroups of five animals each and regenerated nerve fibres were studied at 4, 8, 12 and 16 weeks post operation. Behavioural testing, sciatic nerve functional study, gastrocnemius muscle mass and morphometric indices showed earlier regeneration of axons in AG/Keto than in AG group (p < 0.05). Immunohistochemical study clearly showed more positive location of reactions to S-100 in AG/Keto than in AG group. When loaded in an artery graft, ketoprofen improved functional recovery and morphometric indices of the sciatic nerve. Local usage of this easily accessible therapeutic medicine is cost saving and avoids the problems associated with systemic administration.

  5. Modified function projective synchronization between two different complex networks with delayed couplings and delayed nodes of different dimensions

    NASA Astrophysics Data System (ADS)

    Han, Min; Zhang, Yamei; Zhang, Meng

    2016-05-01

    In this paper, to deal with the problem of modified function projective synchronization (MFPS) between two different networks with delayed couplings and delayed nodes of different dimensions, a hybrid control scheme combining adaptive control and nonlinear control is proposed. First, a more realistic drive-response complex network model is constructed by introducing double delays. Then, we design hybrid feedback controllers to synchronize up the drive and response networks of different dimensions to a scaling function matrix. Based on Lyapunov stability theory and the linear matrix inequality (LMI), we rigorously prove that the MFPS between the proposed drive-response networks can be achieved and meanwhile some sufficient conditions are derived by adopting an appropriate Lyapunov-Krasovskii energy function. Noteably, many existing synchronization settings can be regarded as special cases of the present synchronization framework. Numerical simulation experiments are employed to verify the correctness and the effectiveness of the proposed method.

  6. 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.

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

    SciTech Connect

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

    1986-04-01

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

  8. COGNITIVE FUNCTIONING AND TOLERANCE FOR DELAY OF GRATIFICATION.

    ERIC Educational Resources Information Center

    ZIMILES, HERBERT

    TWO EXPERIMENTS WERE CONDUCTED TO STUDY THE RELATIONSHIP BETWEEN A CHILD'S TOLERANCE FOR DELAY OF GRATIFICATION AND HIS ABILITY TO CONSERVE NUMBER AND PICTURES. OTHER MEASURES OF COGNITION ALSO WERE USED. TOLERANCE FOR DELAY OF GRATIFICATION WAS MEASURED BY THE CHILD'S DECISION TO RECEIVE A PACK OF CANDY AND A TOY ON THE DAY OF TESTING OR TO…

  9. In vivo circulation, clearance, and biodistribution of polyglycerol grafted functional red blood cells.

    PubMed

    Chapanian, Rafi; Constantinescu, Iren; Brooks, Donald E; Scott, Mark D; Kizhakkedathu, Jayachandran N

    2012-04-01

    The in vivo circulation of hyperbranched polyglycerol (HPG) grafted red blood cells (RBCs) was investigated in mice. The number of HPG molecules grafted per RBC was measured using tritium labeled HPGs ((3)H-HPG) of different molecular weights; the values ranged from 1 × 10(5) to 2 × 10(6) molecules per RBC. HPG-grafted RBCs were characterized in vitro by measuring the electrophoretic mobility, complement mediated lysis, and osmotic fragility. Our results show that RBCs grafted with 1.5 × 10(5) HPG molecules per RBC having molecular weights 20 and 60 kDa have similar characteristics as that of control RBCs. The in vivo circulation of HPG-grafted RBCs was measured by a tail vain injection of (3)H-HPG60K-RBC in mice. The radioactivity of isolated RBCs, whole blood, plasma, different organs, urine and feces was evaluated at different time intervals. The portion of (3)H-HPG60K-RBC that survived the first day in mice (52%) remained in circulation for 50 days. Minimal accumulation radioactivity in organs other than liver and spleen was observed suggesting the normal clearance mechanism of modified RBCs. Animals gained normal weights and no abnormalities observed in necropsy analysis. The stability of the ester-amide linker between the RBC and HPG was evaluated by comparing the clearance rate of (3)H-HPG60K-RBC and PKH-26 lipid fluorescent membrane marker labeled HPG60K-RBCs. HPG modified RBCs combine the many advantages of a dendritic polymer and RBCs, and hold great promise in systemic drug delivery and other applications of functional RBC.

  10. Absolute exponential stability of recurrent neural networks with Lipschitz-continuous activation functions and time delays.

    PubMed

    Cao, Jinde; Wang, Jun

    2004-04-01

    This paper investigates the absolute exponential stability of a general class of delayed neural networks, which require the activation functions to be partially Lipschitz continuous and monotone nondecreasing only, but not necessarily differentiable or bounded. Three new sufficient conditions are derived to ascertain whether or not the equilibrium points of the delayed neural networks with additively diagonally stable interconnection matrices are absolutely exponentially stable by using delay Halanay-type inequality and Lyapunov function. The stability criteria are also suitable for delayed optimization neural networks and delayed cellular neural networks whose activation functions are often nondifferentiable or unbounded. The results herein answer a question: if a neural network without any delay is absolutely exponentially stable, then under what additional conditions, the neural networks with delay is also absolutely exponentially stable.

  11. Improvement of left ventricular exercise hemodynamic function after aorta-coronary artery bypass grafting.

    PubMed

    Vlietstra, R E; Chesebro, J H; Frye, R L; Wallace, R B

    1981-01-01

    In 39 patients with coronary artery disease and angina pectoris, exercise hemodynamic evaluation, left ventriculography, and coronary arteriography were performed both before and 3 to 36 months (mean 17 months) after aorta-coronary artery bypass grafting. Of the 32 patients with abnormal exercise hemodynamic responses before operation, 11 returned to normal at the postoperative study (Group N) and 21 remained abnormal (Group A). Preoperative characteristics (mean age, functional class, prior myocardial infarction, left ventriculographic appearance, mean ejection fraction, and mean number of vessels diseased) were similar in the two groups. Of the perioperative and postoperative characteristics examined (mean number of grafts, operative myocardial infarction, postoperative functional class, treadmill test result, and adequacy of left coronary artery revascularization), only the adequacy of left coronary artery revascularization differed between Groups N and A. Eight of 11 Group N and only three of 20 Group A patients had complete revascularization, with patent grafts, of the left coronary artery. We conclude that improved exercise hemodynamic function does occur in some patients after aorta-coronary artery bypass operations. Such improvement is most likely when all major lesions of the left coronary artery are completely revascularized.

  12. Gene transfer of manganese superoxide dismutase extends islet graft function in a mouse model of autoimmune diabetes.

    PubMed

    Bertera, Suzanne; Crawford, Megan L; Alexander, Angela M; Papworth, Glenn D; Watkins, Simon C; Robbins, Paul D; Trucco, Massimo

    2003-02-01

    Islet transplantation is a promising cure for diabetes. However, inflammation, allorejection, and recurrent autoimmune damage all may contribute to early graft loss. Pancreatic islets express lower levels of antioxidant genes than most other tissues of the body, and beta-cells in particular are sensitive to oxidative damage. Therefore, damage from oxidative stress may pose a major obstacle to islet replacement therapy in that both the islet isolation and transplantation processes generate oxygen radicals. To determine whether antioxidant gene overexpression in isolated pancreatic islets can prevent oxidative damage and prolong islet function after transplantation, we used the NOD mouse model to study oxidative stress encountered during both transplantation and autoimmune attack. We transferred an antioxidant gene, manganese superoxide dismutase (MnSOD), by adenoviral infection into isolated islets that were transplanted into streptozotocin-treated NODscid recipient mice. Functioning islet grafts were subsequently exposed to diabetogenic spleen cells and monitored until graft failure. The results show that islet grafts overexpressing MnSOD functioned approximately 50% longer than control grafts. This significant prolongation of graft function suggests that the antioxidant activity of MnSOD is beneficial to transplanted islet survival and may be used in combination with other strategies aimed at islet graft protection.

  13. Real Time Immunophenotyping of Leukocyte Subsets Early after Double Cord Blood Transplantation Predicts Graft Function.

    PubMed

    Li, Jianqiang; Nicoud, Ian; Blake, Joseph; Oliver, David; Cox, Emily; Heimfeld, Shelly; Milano, Filippo; Imren, Suzan; Delaney, Colleen

    2017-03-01

    Cord blood transplantation (CBT) recipients are at increased risk for delayed engraftment and primary graft failure, complications that are often indistinguishable early post-transplantation. Current assays fail to accurately identify recipients with slow hematopoietic recovery and distinguish them from those with pending graft failure. To address this, we prospectively examined the kinetics of immune cell subset recovery in the peripheral blood of 39 patients on days +7 and +14 after double-unit CBT (dCBT) by multiparametric flow cytometry analysis, which we term real-time immunophenotyping (RTIP). RTIP analysis at day +14 revealed distinctive patterns of reconstitution and, importantly, identified patients with slow hematopoietic recovery who went on to engraft. Strikingly, higher absolute numbers of circulating monocytes and natural killer cells at day +14 were predictive of engraftment, but only the absolute number of circulating monocytes was significantly correlated with time to engraftment. This is the first evidence that RTIP on patient peripheral blood mononuclear cells early after dCBT is technically feasible and can be used as a "signature" for predicting the kinetics of hematopoietic recovery. Furthermore, RTIP is a time- and cost-efficient methodology that has the potential to become a clinically feasible diagnostic tool to guide therapeutic interventions in high-risk patients; therefore, its utility should be evaluated in a large cohort of patients.

  14. Nogo-A Neutralization Improves Graft Function in a Rat Model of Parkinson’s Disease

    PubMed Central

    Seiler, Stefanie; Di Santo, Stefano; Widmer, Hans Rudolf

    2016-01-01

    Transplantation of fetal human ventral mesencephalic (VM) dopaminergic neurons into the striatum is a promising strategy to compensate for the characteristic dopamine deficit observed in Parkinson’s disease (PD). This therapeutic approach, however, is currently limited by the high number of fetuses needed for transplantation and the poor survival and functional integration of grafted dopaminergic neurons into the host brain. Accumulating evidence indicates that contrasting inhibitory signals endowed in the central nervous system (CNS) might support neuronal regeneration. Hence, in the present study we aimed at improving survival and integration of grafted cells in the host brain by neutralizing Nogo-A, one of the most potent neurite growth inhibitors in the CNS. For that purpose, VM tissue cultures were transplanted into rats with a partial 6-hydroxydopamine (6-OHDA) lesion causing a hemi-PD model and concomitantly treated for 2 weeks with intra-ventricular infusion of neutralizing anti-Nogo-A antibodies. Motor behavior using the cylinder test was assessed prior to and after transplantation as functional outcome. At the end of the experimental period the number of dopaminergic fibers growing into the host brain, the number of surviving dopaminergic neurons in the grafts as well as graft size was examined. We found that anti-Nogo-A antibody infusion significantly improved the asymmetrical forelimb use observed after lesions as compared to controls. Importantly, a significantly three-fold higher dopaminergic fiber outgrowth from the transplants was detected in the Nogo-A antibody treated group as compared to controls. Furthermore, Nogo-A neutralization showed a tendency for increased survival of dopaminergic neurons (by two-fold) in the grafts. No significant differences were observed for graft volume and the number of dopaminergic neurons co-expressing G-protein-coupled inward rectifier potassium channel subunit two between groups. In sum, our findings support the

  15. Preparation and biocompatibility of grafted functional β-cyclodextrin copolymers from the surface of PET films.

    PubMed

    Jiang, Yan; Liang, Yuan; Zhang, Hongwen; Zhang, Weiwei; Tu, Shanshan

    2014-08-01

    The hydrophobic inert surface of poly(ethylene terephthalate) (PET) film has limited its practical bioapplications, in which case, better biocompatibility should be achieved by surface modification. In this work, the copolymer of functional β-cyclodextrin derivatives and styrene grafted surfaces was prepared via surface-initiated atom transfer radical polymerization (SI-ATRP) on initiator-immobilized PET. The structures, composition, properties, and surface morphology of the modified PET films were characterized by fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), contact angle measurement, and scanning electronic microscopy (SEM). The results show that the surface of PET films was covered by a thick targeted copolymer layer, and the hydrophobic surface of PET was changed into an amphiphilic surface. The copolymer-grafted surfaces were also shown good biocompatibility on which SGC-7901 A549 and A549/DDP cells readily attached and proliferated, demonstrating that the functional copolymer-grafted PET films could be a promising alternative to biomaterials especially for tissue engineering.

  16. 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.

  17. Providing alternative reinforcers to facilitate tolerance to delayed reinforcement following functional communication training.

    PubMed

    Austin, Jillian E; Tiger, Jeffrey H

    2015-09-01

    The earliest stages of functional communication training (FCT) involve providing immediate and continuous reinforcement for a communicative response (FCR) that is functionally equivalent to the targeted problem behavior. However, maintaining immediate reinforcement is not practical, and the introduction of delays is associated with increased problem behavior. The present study evaluated the effects of providing alternative reinforcers during delays to reinforcement with a 13-year-old boy with an intellectual disability. Problem behavior was less likely when alternative reinforcers were available during delays.

  18. Estimation of Delays and Other Parameters in Nonlinear Functional Differential Equations.

    DTIC Science & Technology

    1981-12-01

    FSTIMATION OF DELAYS AND OTHER PARAMETERS IN NONLINEAR FUNCTIONAL DIFFERENTIAL EQUATIONS by K. T. Banks and P. L. Daniel December 1981 LCDS Report #82...ESTIMATION OF DELAYS AND OTHER PARAMETERS IN NONLINEAR FUNCTIONAL DIFFERENTIAL EQUATIONS H. T. Banks and P. L. Daniel ABSTRACT We discuss a spline...based approximation scheme for nonlinear nonautonomous delay differential equations . Convergence results (using dissipative type estimates on the

  19. Multiple-region directed functional connectivity based on phase delays.

    PubMed

    Goelman, Gadi; Dan, Rotem

    2017-03-01

    Network analysis is increasingly advancing the field of neuroimaging. Neural networks are generally constructed from pairwise interactions with an assumption of linear relations between them. Here, a high-order statistical framework to calculate directed functional connectivity among multiple regions, using wavelet analysis and spectral coherence has been presented. The mathematical expression for 4 regions was derived and used to characterize a quartet of regions as a linear, combined (nonlinear), or disconnected network. Phase delays between regions were used to obtain network's temporal hierarchy and directionality. The validity of the mathematical derivation along with the effects of coupling strength and noise on its outcomes were studied by computer simulations of the Kuramoto model. The simulations demonstrated correct directionality for a large range of coupling strength and low sensitivity to Gaussian noise compared with pairwise coherences. The analysis was applied to resting-state fMRI data of 40 healthy young subjects to characterize the ventral visual system, motor system and default mode network (DMN). It was shown that the ventral visual system was predominantly composed of linear networks while the motor system and the DMN were composed of combined (nonlinear) networks. The ventral visual system exhibits its known temporal hierarchy, the motor system exhibits center ↔ out hierarchy and the DMN has dorsal ↔ ventral and anterior ↔ posterior organizations. The analysis can be applied in different disciplines such as seismology, or economy and in a variety of brain data including stimulus-driven fMRI, electrophysiology, EEG, and MEG, thus open new horizons in brain research. Hum Brain Mapp 38:1374-1386, 2017. © 2016 Wiley Periodicals, Inc.

  20. 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".

  1. Renewable and functional wood materials by grafting polymerization within cell walls.

    PubMed

    Cabane, Etienne; Keplinger, Tobias; Merk, Vivian; Hass, Philipp; Burgert, Ingo

    2014-04-01

    A "grafting-from" polymerization approach within and at the complex and heterogeneous macromolecular assembly of wood cell walls is shown. The approach allows for the implementation of novel functionalities in renewable and functional wood-based materials. The native wood structure is retained and used as a hierarchical multiscale framework for a modular two-step polymerization process. The versatility and potential of the approach is shown by a polymerization of either hydrophobic or hydrophilic and pH-responsive monomers in the wood structure. Characterization of the modified wood reveals the presence of polymer in the cell wall, and the new properties of these wood materials are discussed.

  2. Surface functionalization of fluorine-doped tin oxide samples through electrochemical grafting.

    PubMed

    Lamberti, F; Agnoli, S; Brigo, L; Granozzi, G; Giomo, M; Elvassore, N

    2013-12-26

    Transparent conductive oxides are emerging materials in several fields, such as photovoltaics, photoelectrochemistry, and optical biosensing. Their high chemical inertia, which ensured long-term stability on one side, makes challenging the surface modification of transparent conductive oxides; long-term robust modification, high yields, and selective surface modifications are essential prerequisite for any further developments. In this work, we aim at inducing chemical functionality on fluorine-doped tin oxide surfaces (one of the most inexpensive transparent conductive oxide) by means of electrochemical grafting of aryl diazonium cations. The grafted layers are fully characterized by photoemission spectroscopy, cyclic voltammetry, and atomic force microscopy showing linear correlation between surface coverage and degree of modification. The electrochemical barrier effect of modified surfaces was studied at different pH to characterize the chemical nature of the coating. We showed immuno recognition of biotin complex built onto grafted fluorine-doped tin oxides, which opens the perspective of integrating FTO samples with biological-based devices.

  3. Rapid Functional Decline of Activated and Memory Graft-versus-Host-Reactive T Cells Encountering Host Antigens in the Absence of Inflammation.

    PubMed

    Li, Hao Wei; Andreola, Giovanna; Carlson, Alicia L; Shao, Steven; Lin, Charles P; Zhao, Guiling; Sykes, Megan

    2015-08-01

    Inflammation in the priming host environment has critical effects on the graft-versus-host (GVH) responses mediated by naive donor T cells. However, it is unclear how a quiescent or inflammatory environment impacts the activity of GVH-reactive primed T and memory cells. We show in this article that GVH-reactive primed donor T cells generated in irradiated recipients had diminished ability compared with naive T cells to increase donor chimerism when transferred to quiescent mixed allogeneic chimeras. GVH-reactive primed T cells showed marked loss of cytotoxic function and activation, and delayed but not decreased proliferation or accumulation in lymphoid tissues when transferred to quiescent mixed chimeras compared with freshly irradiated secondary recipients. Primed CD4 and CD8 T cells provided mutual help to sustain these functions in both subsets. CD8 help for CD4 cells was largely IFN-γ dependent. TLR stimulation after transfer of GVH-reactive primed T cells to mixed chimeras restored their cytotoxic effector function and permitted the generation of more effective T cell memory in association with reduced PD-1 expression on CD4 memory cells. Our data indicate that an inflammatory host environment is required for the maintenance of GVH-reactive primed T cell functions and the generation of memory T cells that can rapidly acquire effector functions. These findings have important implications for graft-versus-host disease and T cell-mediated immunotherapies.

  4. Delayed motor function and results of vestibular function tests in children with inner ear anomalies.

    PubMed

    Tsuzuku, T; Kaga, K

    1992-05-01

    The relation between the results of vestibular function tests and gross motor development was examined in 4 children with inner ear anomalies. CT scans demonstrated the absence of lateral semicircular canals in both ears in all 4 cases. None responded to caloric stimulation using 40 ml of icewater. In contrast, the damped rotation test elicited per-rotatory nystagmus in all cases. Per-rotatory nystagmus was provoked in only two cases by the Bárány rotation test. Development of gross motor function, especially independent walking, was more delayed in the two children in whom the Bárány rotation test failed to elicit per-rotatory nystagmus.

  5. Delayed onset of gastrointestinal disease in the recipients of bone marrow transplants: a variant graft-versus-host reaction

    SciTech Connect

    Serota, F.T.; Rosenberg, H.K.; Rosen, J.; Koch, P.A.; August, C.S.

    1982-07-01

    The report describes a subacute syndrome consisting of anorexia, mouth ulcers, abdominal pain, and diarrhea which occurred in three allogenic transplant recipients which appears to be distinct from the usual patterns of acute or chronic graft-versus-host disease (GVHD). The patient with myelomonocytic leukemia was treated with cyclophosphamide (60 mg/kg) i.v. 4 and 3 days before and total body X irradiation to 800 rad 1 day before transplantation. The radiation was administered from a 6-Mev source at least 3.5 m from the patient via opposing lateral fields. The patients were maintained in the protected environment until their absolute neutrophil counts (ANC) became greater than 1000/mm/sup 3/. All blood products were irradiated (1500 rad) prior to transfusion. Methotrexate was administered weekly for 100 days to prevent GVHD. (JMT)

  6. α-Melanocyte stimulating hormone treatment in pigs does not improve early graft function in kidney transplants from brain dead donors.

    PubMed

    van Rijt, Willem G; Secher, Niels; Keller, Anna K; Møldrup, Ulla; Chynau, Yahor; Ploeg, Rutger J; van Goor, Harry; Nørregaard, Rikke; Birn, Henrik; Frøkiaer, Jørgen; Nielsen, Søren; Leuvenink, Henri G D; Jespersen, Bente

    2014-01-01

    Delayed graft function and primary non-function are serious complications following transplantation of kidneys derived from deceased brain dead (DBD) donors. α-melanocyte stimulating hormone (α-MSH) is a pleiotropic neuropeptide and its renoprotective effects have been demonstrated in models of acute kidney injury. We hypothesized that α-MSH treatment of the recipient improves early graft function and reduces inflammation following DBD kidney transplantation. Eight Danish landrace pigs served as DBD donors. After four hours of brain death both kidneys were removed and stored for 18 hours at 4°C in Custodiol preservation solution. Sixteen recipients were randomized in a paired design into two treatment groups, transplanted simultaneously. α-MSH or a vehicle was administered at start of surgery, during reperfusion and two hours post-reperfusion. The recipients were observed for ten hours following reperfusion. Blood, urine and kidney tissue samples were collected during and at the end of follow-up. α-MSH treatment reduced urine flow and impaired recovery of glomerular filtration rate (GFR) compared to controls. After each dose of α-MSH, a trend towards reduced mean arterial blood pressure and increased heart rate was observed. α-MSH did not affect expression of inflammatory markers. Surprisingly, α-MSH impaired recovery of renal function in the first ten hours following DBD kidney transplantation possibly due to hemodynamic changes. Thus, in a porcine experimental model α-MSH did not reduce renal inflammation and did not improve short-term graft function following DBD kidney transplantation.

  7. Femoral Aperture Fixation Improves Anterior Cruciate Ligament Graft Function When Added to Cortical Suspensory Fixation

    PubMed Central

    Porter, Mark D.; Shadbolt, Bruce

    2016-01-01

    Background: Recommendations for bone tunnel placement during anterior cruciate ligament (ACL) reconstruction have become more precise. However, these recommendations differ neither with the choice of graft nor with the method of fixation used. The influence of the method of femoral fixation used on the biomechanical function of a soft tissue ACL graft remains unknown. Hypothesis: Our null hypothesis was that adding femoral aperture fixation to femoral cortical fixation, using the same bone tunnels, will not alter the control of anterior translation (AT) and internal rotation (IR) during ACL reconstruction using a hamstring graft. Study Design: Controlled laboratory study. Methods: A total of 22 patients with an acute isolated ACL rupture underwent reconstruction using a single-bundle autologous hamstring graft. Computer navigation was used intraoperatively to plot the AT and IR during the pivot-shift test before reconstruction, after ACL reconstruction using cortical suspensory fixation, and after the addition of femoral aperture fixation. Statistical analysis (analysis of variance) was used to compare the AT and IR during the pivot shift at each stage in the procedure. Results: Before ACL reconstruction, the mean (±SD) AT was 14.2 ± 7.3 mm and mean IR was 17.2° ± 5.5°. After reconstruction using femoral cortical suspension, these figures were significantly reduced to 6.2 ± 3.5 mm and 12.5° ± 3.20°, respectively (P < .001). The addition of the aperture fixation was associated with a further significant reduction to 4.6 ± 3.2 mm and 10.4° ± 2.7°, respectively (P < .001). Conclusion: The addition of femoral aperture fixation to suspensory fixation results in a significant reduction in both the AT and IR that occurs during the pivot-shift assessment immediately after ACL reconstruction using autologous hamstring graft. Clinical Relevance: The most precise positioning of bone tunnels during soft tissue ACL reconstruction needs to take into consideration

  8. Influence of donor–recipient gender mismatch on graft function and survival following lung transplantation†

    PubMed Central

    Alvarez, Antonio; Moreno, Paula; Illana, Jennifer; Espinosa, Dionisio; Baamonde, Carlos; Arango, Elisabet; Algar, Francisco Javier; Salvatierra, Angel

    2013-01-01

    OBJECTIVES In current practice, donors and recipients are not matched for gender in lung transplantation. However, some data have suggested a possible effect of gender combinations on lung transplant outcomes. We examined whether donor–recipient (D/R) gender mismatch is related to adverse outcomes after lung transplantation in terms of early and long-term graft function and survival. METHODS We reviewed 256 donors and lung transplant recipients over a 14-year period. Patients were distributed into four groups: Group A (D/R: female/female), Group B (D/R: male/male), Group C (D/R: female/male), Group D (D/R: male/female). Donor and recipient variables were compared among groups, including early graft function, 30-day mortality, freedom from bronchiolitis obliterans syndrome (BOS), and long-term survival. RESULTS Group A: 57 (22%), Group B: 99 (39%), Group C: 62 (24%), Group D: 38 (15%) transplants (P = 0.001). Donor age was 29 ± 14, 27 ± 12, 33 ± 13 and 23 ± 12 years for Groups A, B, C and D, respectively (P = 0.004). Recipient age was 31 ± 15, 44 ± 17, 42 ± 16 and 30 ± 16 years for Groups A, B, C and D, respectively (P = 0.000). PaO2/FiO2 (mmHg) 24 h post-transplant was: Group A: 276 ± 144, Group B: 297 ± 131, Group C: 344 ± 133 and Group D: 238 ± 138 (P = 0.015). Primary graft dysfunction developed in 23, 14, 17 and 21% of recipients from Groups A, B, C and D, respectively (P = 0.45). Operative mortality was 4.4, 6.5, 5.2 and 2%, for recipients from Groups A, B, C and D, respectively (P = 0.66). Freedom from BOS was 73, 59 and 36% for gender-matched transplants vs 76, 67 and 40% for gender-mismatched transplants at 3, 5 and 10 years, respectively (P = 0.618), without differences among groups. A non-significant survival benefit was observed for female recipients, irrespective of the donor gender. CONCLUSIONS Donor–recipient gender mismatch does not have a negative impact on early graft function and mortality following lung transplantation. There is a

  9. A nonlinear correlation function for selecting the delay time in dynamical reconstructions

    NASA Astrophysics Data System (ADS)

    Aguirre, Luis Antonio

    1995-02-01

    Numerical results discussed in this paper suggest that a function which detects nonlinear correlations in time series usually indicates shorter correlation times than the linear autocorrelation function which is often used for this purpose. The nonlinear correlation function can also detect changes in the data which cannot be distinguished by the linear counterpart. This affects a number of approaches for the selection of the delay time used in the reconstruction of nonlinear dynamics from a single time series based on time delay coordinates.

  10. Preserved Renal Function in Kidney Transplantation over a Thrombosed Aortobifemoral Bypass Graft: The Role of Retrograde Flow and Early Thrombolysis

    PubMed Central

    Jiménez-Alvaro, Sara; Fernández-Rodríguez, Ana; Rivera-Gorrín, Maite; Sánchez, Juan; Chinchilla, Antonio; Marcén, Roberto

    2016-01-01

    Aortobifemoral bypass (ABFB) thrombosis is not uncommon, and when the artery of a renal graft is implanted on a bypass the risk of graft loss is high. We report the case of a 48-year-old woman with a previous history of ABFB under antiplatelet therapy and a kidney allograft implanted on the vascular prosthesis, who presented with acute limb ischemia and severe renal impairment. Imaging techniques revealed a complete thrombosis of the proximal left arm of the ABFB. However, a faint retrograde flow over the graft was observed thanks to the recanalization of distal left bypass by collateral native arteries. This unusual situation not previously reported in a kidney transplant setting, together with an early diagnosis, allowed graft survival until an early local thrombolysis resolved the problem. Two years later, renal function remains normal. PMID:27579209

  11. Examining relationships between executive functioning and delay aversion in attention deficit hyperactivity disorder.

    PubMed

    Karalunas, Sarah L; Huang-Pollock, Cynthia L

    2011-01-01

    Although motivation and cognition are often examined separately, recent theory suggests that a delay-averse motivational style may negatively impact development of executive functions (EFs), such as working memory (WM) and response inhibition (RI) for children with Attention Deficit Hyperactivity Disorder (ADHD; Sonuga-Barke, 2002 ). This model predicts that performance on delay aversion and EF tasks should be correlated for school-age children with ADHD. However, tests of these relationships remain sparse. Forty-five children ages 8 to 12 with ADHD and 46 non-ADHD controls completed tasks measuring EFs and delay aversion. Children with ADHD had poorer WM and RI than non-ADHD controls, as well as nonsignificantly worse delay aversion. Consistent with previous research, RI was not related to delay aversion. However, delay aversion did predict WM scores for children with and without ADHD. Implications for the dual-pathway hypothesis and future research on cognitive and motivational processing in ADHD are discussed.

  12. Estimation of time- and state-dependent delays and other parameters in functional differential equations

    NASA Technical Reports Server (NTRS)

    Murphy, K. A.

    1988-01-01

    A parameter estimation algorithm is developed which can be used to estimate unknown time- or state-dependent delays and other parameters (e.g., initial condition) appearing within a nonlinear nonautonomous functional differential equation. The original infinite dimensional differential equation is approximated using linear splines, which are allowed to move with the variable delay. The variable delays are approximated using linear splines as well. The approximation scheme produces a system of ordinary differential equations with nice computational properties. The unknown parameters are estimated within the approximating systems by minimizing a least-squares fit-to-data criterion. Convergence theorems are proved for time-dependent delays and state-dependent delays within two classes, which say essentially that fitting the data by using approximations will, in the limit, provide a fit to the data using the original system. Numerical test examples are presented which illustrate the method for all types of delay.

  13. Estimation of time- and state-dependent delays and other parameters in functional differential equations

    NASA Technical Reports Server (NTRS)

    Murphy, K. A.

    1990-01-01

    A parameter estimation algorithm is developed which can be used to estimate unknown time- or state-dependent delays and other parameters (e.g., initial condition) appearing within a nonlinear nonautonomous functional differential equation. The original infinite dimensional differential equation is approximated using linear splines, which are allowed to move with the variable delay. The variable delays are approximated using linear splines as well. The approximation scheme produces a system of ordinary differential equations with nice computational properties. The unknown parameters are estimated within the approximating systems by minimizing a least-squares fit-to-data criterion. Convergence theorems are proved for time-dependent delays and state-dependent delays within two classes, which say essentially that fitting the data by using approximations will, in the limit, provide a fit to the data using the original system. Numerical test examples are presented which illustrate the method for all types of delay.

  14. 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.

  15. Serum liver-type fatty acid-binding protein predicts recovery of graft function after kidney transplantation from donors after cardiac death.

    PubMed

    Kawai, Akihiro; Kusaka, Mamoru; Kitagawa, Fumihiko; Ishii, Junichi; Fukami, Naohiko; Maruyama, Takahiro; Sasaki, Hitomi; Shiroki, Ryoichi; Kurahashi, Hiroki; Hoshinaga, Kiyotaka

    2014-06-01

    Kidneys procured by donation after cardiac death (DCD) may increase the donor pool but are associated with high incidence of delayed graft function (DGF). Urinary liver-type fatty acid-binding protein (L-FABP) level is an early biomarker of renal injury after kidney transplantation (KTx); however, its utility is limited in DGF cases owing to urine sample unavailability. We examined whether serum L-FABP level predicts functional recovery of transplanted DCD kidneys. Consecutive patients undergoing KTx from living related donors (LD), brain-dead donors (BD), or DCD were retrospectively enrolled. Serum L-FABP levels were measured from samples collected before and after KTx. Serum L-FABP decreased rapidly in patients with immediate function, slowly in DGF patients, and somewhat increased in DGF patients requiring hemodialysis (HD) for >1 wk. Receiver-operating characteristic curve analysis demonstrated that DGF was predicted with 84% sensitivity (SE) and 86% specificity (SP) at cutoff of 9.0 ng/mL on post-operative day (POD) 1 and 68% SE and 90% SP at 6.0 on POD 2. DGF >7 d was predicted with 83% SE and 78% SP at 11.0 on POD 1 and 67% SE and 78% SP at 6.5 on POD 2. Serum L-FABP levels may predict graft recovery and need for HD after DCD KTx.

  16. Polydopamine-mediated immobilization of multiple bioactive molecules for the development of functional vascular graft materials.

    PubMed

    Lee, Yu Bin; Shin, Young Min; Lee, Ji-Hye; Jun, Indong; Kang, Jae Kyeong; Park, Jong-Chul; Shin, Heungsoo

    2012-11-01

    In this study, we introduced a simple method for polydopamine-mediated immobilization of dual bioactive factors for the preparation of functionalized vascular graft materials. Polydopamine was deposited on elastic and biodegradable poly(lactic acid-co-ɛ-caprolactone) (PLCL) films, and a cell adhesive RGD-containing peptide and basic fibroblast growth factor were subsequently immobilized by simple dipping. We used an enzyme-linked immunosorbent assay and fluorescamine assay to confirm that we had stably immobilized bioactive molecules on the polydopamine-coated PLCL film in a reaction time-dependent manner. When human umbilical vein endothelial cells (HUVEC) were cultured on the prepared substrates, the number of adherent cells and proliferation of HUVEC for up to 14 days were greatest on the film immobilized with dual factors. On the other hand, the film immobilized with RGD peptide exhibited the highest migration speed compared to the other groups. The expression of cluster of differentiation 31 and von Willebrand factor, which indicates maturation of endothelial cells, was highly stimulated in the dual factor-immobilized group, and passively adsorbed factors showed a negligible effect. The immobilization of bioactive molecules inspired by polydopamine was successful, and adhesion, migration, proliferation and differentiation of HUVEC were synergistically accelerated by the presence of multiple signaling factors. Collectively, our results have demonstrated that a simple coating with polydopamine enables the immobilization of multiple bioactive molecules for preparation of polymeric functionalized vascular graft materials.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Cochlear Delay and Medial Olivocochlear Functioning in Children with Suspected Auditory Processing Disorder

    PubMed Central

    Boothalingam, Sriram; Allan, Chris; Allen, Prudence; Purcell, David

    2015-01-01

    Behavioral manifestations of processing deficits associated with auditory processing disorder (APD) have been well documented. However, little is known about their anatomical underpinnings, especially cochlear processing. Cochlear delays, a proxy for cochlear tuning, measured using stimulus frequency otoacoustic emission (SFOAE) group delay, and the influence of the medial olivocochlear (MOC) system activation at the auditory periphery was studied in 23 children suspected with APD (sAPD) and 22 typically developing (TD) children. Results suggest that children suspected with APD have longer SFOAE group delays (possibly due to sharper cochlear tuning) and reduced MOC function compared to TD children. Other differences between the groups include correlation between MOC function and SFOAE delay in quiet in the TD group, and lack thereof in the sAPD group. MOC-mediated changes in SFOAE delay were in opposite directions between groups: increase in delay in TD vs. reduction in delay in the sAPD group. Longer SFOAE group delays in the sAPD group may lead to longer cochlear filter ringing, and potential increase in forward masking. These results indicate differences in cochlear and MOC function between sAPD and TD groups. Further studies are warranted to explore the possibility of cochlea as a potential site for processing deficits in APD. PMID:26317850

  20. Recovery of erectile function comparing autologous nerve grafts, unseeded conduits, Schwann-cell-seeded guidance tubes and GDNF-overexpressing Schwann cell grafts

    PubMed Central

    Buchner, Alexander; Matiasek, Kaspar; Schlenker, Boris; Stief, Christian; Weidner, Norbert

    2016-01-01

    ABSTRACT Dissection of the cavernous nerves during radical prostatectomy for prostate cancer eliminates spontaneous erections. Using the rat as an experimental model, we compared the regenerative capacity of autologous nerve grafts and Schwann-cell-seeded nerve guides. After bilateral excision of cavernous nerve segments, cavernous nerves were reconstructed using unseeded silicon tubes, nerve autografts and silicon tubes seeded with either Glial-cell-line-derived (GDNF)-overexpressing or green fluorescent protein (GFP)-expressing Schwann cells (SCs) (16 study nerves per group). Control groups underwent either a sham operation or bilateral excision of cavernous nerve segments without repair. After 12 weeks erectile function was assessed by neurostimulation and intracavernous pressure (ICP) measurement. The reconstructed nerve segments were excised and histologically analyzed. We demonstrated an intact erectile response upon neurostimulation in 25% (4/16) of autologous nerve grafts, in 50% (8/16) of unseeded tubes, in 75% (12/16) of the Schwann-cell–GFP group and in 93.75% (15/16) of the GDNF group. ICP was significantly increased when comparing the Schwann-cell–GFP group with nerve autografts, unseeded conduits and negative controls (P<0.005). In conclusion, Schwann-cell-seeded scaffolds combined with neurotrophic factors are superior to unseeded tubes and autologous nerve grafts. They present a promising therapeutic approach for the repair of erectile nerve gaps. PMID:27874834

  1. Facile functionalization of multilayer fullerenes (carbon nano-onions) by nitrene chemistry and "grafting from" strategy.

    PubMed

    Zhou, Li; Gao, Chao; Zhu, Dandan; Xu, Weijian; Chen, Fanqing Frank; Palkar, Amit; Echegoyen, Luis; Kong, Eric Siu-Wai

    2009-01-01

    Facile functionalization of multilayer fullerenes (carbon nano-onions, CNOs) was carried out by [2+1] cycloaddition of nitrenes. The products were further derivatized by using the "grafting from" strategy of in situ ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Using one-step nitrene chemistry with high-energy reagents, such as azidoethanol and azidoethyl 2-bromo-2-methyl propanoate, in N-methyl-2-pyrrolidone at 160 degrees C for 16 h, hydroxyl and bromide functionalities were introduced onto the surfaces of CNOs. These hydroxyl CNOs (CNO-OH) and bromic CNOs (CNO-Br) were extensively characterized by various techniques such as thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), Raman spectroscopy and X-ray photo electron spectroscopy (XPS). TGA measurements indicated that the surface hydroxyl and bromide group density reached 1.49 and 0.49 mmol g(-1), respectively. The as-functionalized CNOs showed much better solubility in solvents than pristine CNOs. The CNO-OH were also observed to fluoresce at lambda = 453 nm in water. The CNO-OH and CNO-Br can be conveniently utilized as macroinitiators to conduct surface-initiated in-situ polymerizations. Poly(epsilon-caprolactone) (PCL, 45 wt%) and polystyrene (PS, 60 wt%) were then grafted from surfaces of CNOs through the ROP of epsilon-caprolactone with the macroinitiator CNO-OH and the ATRP of styrene with the macroinitiator CNO-Br, respectively. The structures and morphology of the resulting products were characterized by (1)H NMR, scanning electron microscopy (SEM), TEM, and atomic force microscopy (AFM). The polymer functionalized CNOs have good solubility/dispersibility in common organic solvents. The facile and scalable functionalization approaches can pave the way for the comprehensive investigation of chemistry of CNOs and fabrication of novel CNO-based nanomaterials and nanodevices.

  2. Differential Characteristics of Kidney Transplant Recipients According to 1-Year Chronic Kidney Disease Stage 3a and Stage 3b Graft Function.

    PubMed

    Baek, Chung Hee; Kim, Hyosang; Yang, Won Seok; Han, Duck Jong; Park, Su-Kil

    2017-04-01

    The outcomes of transplantation have improved, but more than 50% of kidney transplantation (KT) recipients are still reported to have renal function of chronic kidney disease (CKD) stage 3 at 1 year after KT. We reviewed all 1235 patients who received a KT in our institution between 2008 and 2012. Among these recipients, 77 and 289 cases were included in the estimated glomerular filtration rate (eGFR) at 1 year after KT 30-44 (CKD stage 3b) group and eGFR 45-59 (CKD stage 3a) group, respectively. Longer duration of dialysis (odds ratio [OR] = 1.007, 95% confidence interval [CI], 1.000-1.014, P = 0.047), older donors (OR = 1.064, 95% CI, 1.031-1.098, P < 0.001), delayed graft function (OR = 3.601, 95% CI, 1.031-1.098, P < 0.001), BK virus infection (OR = 2.567, 95% CI, 1.242-5.305, P = 0.011), and pneumonia (OR = 4.451, 95% CI, 1.388-14.279, P = 0.012) were contributing factors to eGFR 30-44 mL/min. Especially, ureteral stricture occurred more frequently in eGFR 30-44 group of deceased donor KT. However, acute rejection was not a significant risk factor of lower eGFR. Graft survival was better in the eGFR 45-59 group. However, this difference was smaller in deceased donor KT. Infections and urologic complications are also important contributing factors of lower graft function in CKD stage 3. In addition, dividing CKD stage 3 into subgroups might be more useful in living donor kidney transplantation.

  3. 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.

  4. Bilayered vascular graft derived from human induced pluripotent stem cells with biomimetic structure and function

    PubMed Central

    Nakayama, Karina H; Joshi, Prajakta A; Lai, Edwina S; Gujar, Prachi; Joubert, Lydia-M; Chen, Bertha; Huang, Ngan F

    2015-01-01

    Background: We developed an aligned bi-layered vascular graft derived from human induced pluripotent stem cells (iPSCs) that recapitulates the cellular composition, orientation, and anti-inflammatory function of blood vessels. Materials & methods: The luminal layer consisted of longitudinal-aligned nanofibrillar collagen containing primary endothelial cells (ECs) or iPSC-derived ECs (iPSC-ECs). The outer layer contained circumferentially oriented nanofibrillar collagen with primary smooth muscle cells (SMCs) or iPSC-derived SMCs(iPSC-SMCs). Results: On the aligned scaffolds, cells organized F-actin assembly within 8º from the direction of nanofibrils. When compared to randomly-oriented scaffolds, EC-seeded aligned scaffolds had significant reduced inflammatory response, based on adhesivity to monocytes. Conclusion: This study highlights the importance of anisotropic scaffolds in directing cell form and function, and has therapeutic significance as physiologically relevant blood vessels. PMID:26440211

  5. Lysozyme immobilization via adsorption process using sulphonic acid functionalized silane grafted copolymer.

    PubMed

    Anirudhan, T S; Rauf, Tharun A

    2013-07-01

    A unique silane based adsorbent material, [stearyl alcohol (SA)-grafted-epichlorohydrin (E)]-grafted-aminoproypyl silanetriol (APST) was synthesized and functionalized with sulphonyl groups via sulphonation process [(SA-g-E)-g-APST/SO3H]. The adsorbent material characterization was done by FTIR, XRD, and TGA analysis. Immobilization of protein Lysozyme (LYZ) using batch adsorption process was carried out for studying the protein-particle interaction. The most suitable pH for maximum adsorption was found to be 7.0. Pseudo-second-order kinetic model was found to be the best fit and the adsorption equilibrium was attained within 3h. Studies on diffusion parameters explained that the adsorption mechanism was controlled by film diffusion mode. The adsorption process was then evaluated using the various isotherm models and the Sips isotherm model proved to be the best fit with a maximum adsorption capacity of 37.68 mg/g. The isotherm favorability of the adsorption process was calculated by calculating the separation factor (R(L)) and the values confirmed the favorability of the adsorption process. Studies on adsorption percentage with respect to temperature and thermodynamic studies revealed that adsorption process is exothermic, spontaneous with maximum entropy. Batch adsorption/desorption studies in acidic medium, for over six cycles showed the repeatability and regeneration capability of the adsorbent material (SA-g-E)-g-APST/SO3H.

  6. Antigens protected functional red blood cells by the membrane grafting of compact hyperbranched polyglycerols.

    PubMed

    Chapanian, Rafi; Constantinescu, Iren; Brooks, Donald E; Scott, Mark D; Kizhakkedathu, Jayachandran

    2013-01-02

    Red blood cell (RBC) transfusion is vital for the treatment of a number of acute and chronic medical problems such as thalassemia major and sickle cell anemia. Due to the presence of multitude of antigens on the RBC surface (~308 known antigens), patients in the chronic blood transfusion therapy develop alloantibodies due to the miss match of minor antigens on transfused RBCs. Grafting of hydrophilic polymers such as polyethylene glycol (PEG) and hyperbranched polyglycerol (HPG) forms an exclusion layer on RBC membrane that prevents the interaction of antibodies with surface antigens without affecting the passage of small molecules such as oxygen, glucose, and ions. At present no method is available for the generation of universal red blood donor cells in part because of the daunting challenge presented by the presence of large number of antigens (protein and carbohydrate based) on the RBC surface and the development of such methods will significantly improve transfusion safety, and dramatically improve the availability and use of RBCs. In this report, the experiments that are used to develop antigen protected functional RBCs by the membrane grafting of HPG and their characterization are presented. HPGs are highly biocompatible compact polymers, and are expected to be located within the cell glycocalyx that surrounds the lipid membrane and mask RBC surface antigens.

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

    PubMed Central

    Tscherter, Anne; Heidemann, Martina; Kleinlogel, Sonja; Streit, Jürg

    2016-01-01

    Presently there exists no cure for spinal cord injury (SCI). However, transplantation of embryonic tissue into spinal cord (SC) lesions resulted in axon outgrowth across the lesion site and some functional recovery, fostering hope for future stem cell therapies. Although in vivo evidence for functional recovery is given, the exact cellular mechanism of the graft support remains elusive: either the grafted cells provide a permissive environment for the host tissue to regenerate itself or the grafts actually integrate functionally into the host neuronal network reconnecting the separated SC circuits. We tested the two hypotheses in an in vitro SC lesion model that is based on propagation of activity between two rat organotypic SC slices in culture. Transplantation of dissociated cells from E14 rat SC or forebrain (FB) re-established the relay of activity over the lesion site and thus, provoked functional regeneration. Combining patch-clamp recordings from transplanted cells with network activity measurements from the host tissue on multi-electrode arrays (MEAs) we here show that neurons differentiate from the grafted cells and integrate into the host circuits. Optogenetic silencing of neurons developed from transplanted embryonic mouse FB cells provides clear evidence that they replace the lost neuronal connections to relay and synchronize activity between the separated SC circuits. In contrast, transplantation of neurospheres (NS) induced neither the differentiation of mature neurons from the grafts nor an improvement of functional regeneration. Together these findings suggest, that the formation of neuronal relays from grafted embryonic cells is essential to re-connect segregated SC circuits. PMID:27708562

  8. Amine functionalized radiation-induced grafted water hyacinth fibers for Pb2+, Cu2+ and Cr3+ uptake

    NASA Astrophysics Data System (ADS)

    Madrid, Jordan F.; Nuesca, Guillermo M.; Abad, Lucille V.

    2014-04-01

    An amine group containing fibrous adsorbent was prepared by reaction of grafted water hyacinth fibers with ethylenediamine. Glycidyl methacrylate (GMA) was grafted onto water hyacinth fibers using gamma radiation induced graft polymerization through simultaneous grafting technique and this was used as base material for producing the amine type adsorbents. The conversion of the epoxy group from GMA into amine group was investigated. The concentration of ethylenediamine solution that gave the highest amine functional group density was 50% by volume in 2-propanol. The amine functionalized water hyacinth fibers were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), and Energy Dispersive X-ray Spectroscopy (EDX). Information derived from these analyses confirms the successful conversion of the epoxy group. The amine-type adsorbent was evaluated for its uptake of Pb2+, Cu2+ and Cr3+ from aqueous solutions. The initial concentration of the metal ions and pH of the solutions were found to influence the amount of metal ions adsorbed by the amine-type adsorbent. The kinetics of adsorption was observed to follow Lagergren's first order equation. Results of ion sorption studies indicate that gamma radiation-induced grafting and subsequent chemical modification improved the ion sorption behaviour of water hyacinth fibers.

  9. Adsorption characteristics of cadmium(II) onto functionalized poly(hydroxyethylmethacrylate)-grafted coconut coir pith.

    PubMed

    Anirudhan, Thayyath Sreenivasan; Divya, Lekshmi; Rijith, Sreenivasan

    2010-07-01

    This study explored the feasibility of utilizing a novel adsorbent, poly(hydroxyethylmethacrylate)-grafted coconut coir pith with carboxyl functionality (PGCP-COOH) for the removal of cadmium(II) from water and wastewater. Maximum removal of 99.9% was observed for an initial concentration of 25 mg/L at pH 6.0 and adsorbent dose of 2.0 g/L. The first-order reversible kinetic model and Langmuir isotherm model were resulted in high correlation coefficients and described well the adsorption of Cd(II) onto PGCP-COOH. The complete removal of 22.4 mg/L Cd(II) from fertilizer industry wastewater was achieved by 2.0 g/L PGCP-COOH. The reusability of the PGCP-COOH for several cycles was demonstrated using 0.1 M HCl solution.

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

    SciTech Connect

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

    1986-10-01

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

  11. Impact of Intensive Physiotherapy on Cognitive Function after Coronary Artery Bypass Graft Surgery

    PubMed Central

    Cavalcante, Elder dos Santos; Magario, Rosmeiri; Conforti, César Augusto; Cipriano Júnior, Gerson; Arena, Ross; Carvalho, Antonio Carlos C.; Buffolo, Enio; Luna Filho, Bráulio

    2014-01-01

    Background Coronary artery bypass graft (CABG) is a standard surgical option for patients with diffuse and significant arterial plaque. This procedure, however, is not free of postoperative complications, especially pulmonary and cognitive disorders. Objective This study aimed at comparing the impact of two different physiotherapy treatment approaches on pulmonary and cognitive function of patients undergoing CABG. Methods Neuropsychological and pulmonary function tests were applied, prior to and following CABG, to 39 patients randomized into two groups as follows: Group 1 (control) – 20 patients underwent one physiotherapy session daily; and Group 2 (intensive physiotherapy) – 19 patients underwent three physiotherapy sessions daily during the recovery phase at the hospital. Non-paired and paired Student t tests were used to compare continuous variables. Variables without normal distribution were compared between groups by using Mann-Whitney test, and, within the same group at different times, by using Wilcoxon test. The chi-square test assessed differences of categorical variables. Statistical tests with a p value ≤ 0.05 were considered significant. Results Changes in pulmonary function were not significantly different between the groups. However, while Group 2 patients showed no decline in their neurocognitive function, Group 1 patients showed a decline in their cognitive functions (P ≤ 0.01). Conclusion Those results highlight the importance of physiotherapy after CABG and support the implementation of multiple sessions per day, providing patients with better psychosocial conditions and less morbidity. PMID:25352459

  12. Predictors of cognitive function in candidates for coronary artery bypass graft surgery.

    PubMed

    Ernest, Christine S; Elliott, Peter C; Murphy, Barbara M; Le Grande, Michael R; Goble, Alan J; Higgins, Rosemary O; Worcester, Marian U C; Tatoulis, James

    2007-03-01

    Candidates for coronary artery bypass graft surgery have been found to exhibit reduced cognitive function prior to surgery. However, little is known regarding the factors that are associated with pre-bypass cognitive function. A battery of neuropsychological tests was administered to a group of patients listed for bypass surgery (n = 109). Medical, sociodemographic and emotional predictors of cognitive function were investigated using structural equation modeling. Medical factors, namely history of hypertension and low ejection fraction, significantly predicted reduced cognitive function, as did several sociodemographic characteristics, namely older age, less education, non-English speaking background, manual occupation, and male gender. One emotional variable, confusion and bewilderment, was also a significant predictor whereas anxiety and depression were not. When significant predictors from the three sets of variables were included in a combined model, three of the five sociodemographic characteristics, namely age, non-English speaking background and occupation, and the two medical factors remained significant. Apart from sociodemographic characteristics, medical factors such as a history of hypertension and low ejection fraction significantly predicted reduced cognitive function in bypass candidates prior to surgery.

  13. Molecular pathways involved in loss of kidney graft function with tubular atrophy and interstitial fibrosis.

    PubMed

    Maluf, Daniel G; Mas, Valeria R; Archer, Kellie J; Yanek, Kenneth; Gibney, Eric M; King, Anne L; Cotterell, Adrian; Fisher, Robert A; Posner, Marc P

    2008-01-01

    Loss of kidney graft function with tubular atrophy (TA) and interstitial fibrosis (IF) causes most kidney allograft losses. We aimed to identify the molecular pathways involved in IF/TA progression. Kidney biopsies from normal kidneys (n = 24), normal allografts (n = 6), and allografts with IF/TA (n = 17) were analyzed using high-density oligonucleotide microarray. Probe set level tests of hypotheses tests were conducted to identify genes with a significant trend in gene expression across the three groups using Jonckheere-Terpstra test for trend. Interaction networks and functional analysis were used. An unsupervised hierarchical clustering analysis showed that all the IF/TA samples were associated with high correlation. Gene ontology classified the differentially expressed genes as related to immune response, inflammation, and matrix deposition. Chemokines (CX), CX receptor (for example, CCL5 and CXCR4), interleukin, and interleukin receptor (for example, IL-8 and IL10RA) genes were overexpressed in IF/TA samples compared with normal allografts and normal kidneys. Genes involved in apoptosis (for example, CASP4 and CASP5) were importantly overexpressed in IF/TA. Genes related to angiogenesis (for example, ANGPTL3, ANGPT2, and VEGF) were downregulated in IF/TA. Genes related to matrix production-deposition were upregulated in IF/TA. A distinctive gene expression pattern was observed in IF/TA samples compared with normal allografts and normal kidneys. We were able to establish a trend in gene expression for genes involved in different pathways among the studied groups. The top-scored networks were related to immune response, inflammation, and cell-to-cell interaction, showing the importance of chronic inflammation in progressive graft deterioration.

  14. Sexual function in women after rectocele repair with acellular porcine dermis graft vs site-specific rectovaginal fascia repair.

    PubMed

    Novi, Joseph M; Bradley, Catherine S; Mahmoud, Najjia N; Morgan, Mark A; Arya, Lily A

    2007-10-01

    The objective of the study was to compare preoperative and postoperative sexual function between women undergoing rectocele repair with porcine dermis graft and women undergoing site-specific repair of rectovaginal fascia. A standardized, validated questionnaire (Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire [PISQ]) was used to collect preoperative sexual function data from 100 patients with rectocele pelvic organ prolapse quantification stage 2 or greater. Fifty women underwent rectocele repair utilizing porcine dermis graft (group 1) and 50 women underwent a site-specific repair of the rectovaginal fascia (group 2). The same questionnaire was administered to all subjects 6 months after surgery. The two groups were similar in age, race, parity, prior hysterectomy, and postmenopausal hormone use. Preoperative sexual function scores were similar in the two groups (group 1 81.4+/-7.3 and group 2: 83.6+/-8.2, p=1.0). Six months after surgery, PISQ scores in group 1 significantly increased (score increase 19.9+/-2.2, p=0.01). The mean increase in PISQ scores for group 2 was 6.9+/-3.1 (p=0.08). When compared with group 2, subjects undergoing rectocele repair with porcine dermis graft scored significantly higher on the PISQ 6 months after surgery (group 1 101.3+/-6.4 and group 2 89.7+/-7.1, p=0.01). We conclude that rectocele repair using porcine dermis graft is associated with improved sexual functioning when compared with site-specific rectovaginal fascia repair.

  15. Stability Analysis of Uncertain Switched Delay Systems: A Time-Varying Lyapunov Function Approach

    NASA Astrophysics Data System (ADS)

    Huang, Ganji; Luo, Shixian; Chen, Wu-Hua

    Exponential stability for switched systems with uncertain parameters and time-varying delay is considered in this paper. The parametric uncertainties are assumed to be time-varying and norm-bounded. By introducing a novel piecewise time-varying Lyapunov function and using Razumikhin techniques, some linear matrix inequalities (LMIs) stability criteria are derived to guarantee the exponential stability of the switched delay systems. A numerical example is presented to demonstrate the effectiveness of the proposed method.

  16. Arteriolar hyalinization in implantation kidney biopsies as a predictor of graft function.

    PubMed

    Wazna, E; Pazik, J; Perkowska-Ptasińska, A; Lewandowski, Z; Nazarewski, S; Chmura, A; Durlik, M

    2009-10-01

    The shortage of organs suitable for transplantation has caused a constant evolution of donor acceptance criteria, making an implantation biopsy a valuable tool to predict kidney allograft survival. Preimplantation vascular changes may be divided into sclerosis or intimal fibrous thickening or arteriolar hyalinization. Increasing evidence has indicated their impact on graft function. The aim of this study was to evaluate the significance of preimplantation arteriolar hyalinization for the stability of kidney allograft function. Among a prospective cohort study of 53 kidney recipients (implantation: 2006-2007) who showed serum creatinine values between 1 and 2 mg/dL at 3 months after engraftment, the mean observation time was 24 +/- 8.7 months. At the end of the observation, kidney function as defined by the estimated glomerular filtration rate by the Cockcroft-Gault formula (eGFR C-G) was significantly diminished in individuals with preimplantation evidences of arteriolar hyalinization (mean values: 51.2 +/- 14.8 and 62.0 +/- 16.7, respectively; P < .03) or serum creatinine concentrations (1.76 +/- 0.36 vs 1.51 +/- 0.48 mg/dL; P < .09). The negative influence of arteriolar hyalinosis on allograft function was time-dependent; an early satisfactory filtration rate did not preclude progressive kidney dysfunction.

  17. Functionalization of lignin through ATRP grafting of poly(2-dimethylaminoethyl methacrylate) for gene delivery.

    PubMed

    Liu, Xiaohong; Yin, Hui; Zhang, Zhongxing; Diao, Bishuo; Li, Jun

    2015-01-01

    The biomass kraft lignin was modified into lignin-based macroinitiators (LnMI) through esterification of the alcohol and phenol functional groups on lignin backbone with 2-bromo-isobutyric bromide under mild condition. Then a series of cationic amphiphilic lignin-based graft copolymers were synthesized by atom transfer radical polymerization (ATRP) of 2-(dimethylamino)ethyl methacrylate (DMAEMA) starting from the lignin-based macroinitiators. These copolymers, denoted as LnPDMAEMA, had a hyperbranched structure with a hydrophobic backbone of lignin and multiple cationic hydrophilic arms of PDMAEMA. The LnPDMAEMA copolymers were characterized by (1)H NMR and elemental analysis (EA), and studied in terms of their DNA binding capability, formation of nanoparticles with plasmid DNA (pDNA), cytotoxicity, and gene transfection in cultured cells. It was found that all the copolymers could efficiently compact pDNA into nanoparticles with sizes ranging from 100 to 200 nm at N/P ratios of 5 or higher. The cytotoxicity of these copolymers depends greatly on the chain length of PDMAEMA arms, the longer the PAMAEMA chain the higher the cytotoxicity. Luciferase assay was used to study the in vitro gene transfection for the LnPDMAEMA copolymers in different cell lines. The gene transfection efficiency of these copolymers was dependent on the grafted PDMAEMA chain length and N/P ratio. Generally, the transfection efficiency decreased with the increase of PAMAEMA length at N/P ratio of 20 or higher. It is very interesting that one of the LnPDMAEMA copolymers with very short arm length (degree of average DMAEMA units=5.5) showed excellent in vitro transfection efficiency that was comparable or even higher than that of branched PEI (25K). These novel biomass-based LnPDMAEMA hyperbranched copolymers can be a promising nonviral gene vectors for future gene delivery application.

  18. Impact of recovery of renal function on long-term mortality after coronary artery bypass grafting.

    PubMed

    Mehta, Rajendra H; Honeycutt, Emily; Patel, Uptal D; Lopes, Renato D; Shaw, Linda K; Glower, Donald D; Harrington, Robert A; Califf, Robert M; Sketch, Michael H

    2010-12-15

    Whether prognosis differs in acute renal failure (ARF) after coronary artery bypass grafting (CABG) in patients with and without recovery of renal function is not known. We studied patients who had CABG at Duke University Medical Center (1995 to 2008). ARF was defined as an increase in peak creatinine ≥50% after CABG or ≥0.7 mg/dl above baseline or need for new dialysis. Patients were categorized into 3 groups: (1) no ARF after CABG, (2) ARF after CABG and completely recovered renal function at day 7 (return of creatinine to no higher than baseline and no dialysis), or (3) ARF after CABG with no recovery of renal function at day 7 (creatinine no higher than baseline or new dialysis). Main outcome measurement was risk-adjusted long-term mortality (excluding death ≤7 days). ARF after CABG occurred in 2,083 of 10,415 patients (20%) and completely recovered in 703 (33.7%). Risk-adjusted mortality was highest in patients with ARF without recovery of renal function (hazard ratios 1.47, 95% confidence interval 1.34 to 1.62) and intermediate in those with ARF but completely recovered renal function (hazard ratios 1.21, 95% confidence interval 1.07 to 1.37, referent no-ARF group). Mortality was lower in patients with ARF compared to those without complete recovery of renal function (p = 0.0083). In conclusion, in patients with ARF after CABG, complete recovery of renal function was associated with significantly lower long-term mortality compared to those without such recovery, although this was significantly higher than in those without ARF. Thus, major emphasis should be on prevention of ARF in patients undergoing CABG.

  19. Providing Alternative Reinforcers to Facilitate Tolerance to Delayed Reinforcement Following Functional Communication Training

    ERIC Educational Resources Information Center

    Austin, Jillian E.; Tiger, Jeffrey H.

    2015-01-01

    The earliest stages of functional communication training (FCT) involve providing immediate and continuous reinforcement for a communicative response (FCR) that is functionally equivalent to the targeted problem behavior. However, maintaining immediate reinforcement is not practical, and the introduction of delays is associated with increased…

  20. EEG functional connectivity, axon delays and white matter disease

    PubMed Central

    Nunez, Paul L.; Srinivasan, Ramesh; Fields, R. Douglas

    2016-01-01

    Objective Both structural and functional brain connectivities are closely linked to white matter disease. We discuss several such links of potential interest to neurologists, neurosurgeons, radiologists, and non-clinical neuroscientists. Methods Treatment of brains as genuine complex systems suggests major emphasis on the multi-scale nature of brain connectivity and dynamic behavior. Cross-scale interactions of local, regional, and global networks are apparently responsible for much of EEG's oscillatory behaviors. Finite axon propagation speed, often assumed to be infinite in local network models, is central to our conceptual framework. Results Myelin controls axon speed, and the synchrony of impulse traffic between distant cortical regions appears to be critical for optimal mental performance and learning. Results Several experiments suggest that axon conduction speed is plastic, thereby altering the regional and global white matter connections that facilitate binding of remote local networks. Conclusions Combined EEG and high resolution EEG can provide distinct multi-scale estimates of functional connectivity in both healthy and diseased brains with measures like frequency and phase spectra, covariance, and coherence. Significance White matter disease may profoundly disrupt normal EEG coherence patterns, but currently these kinds of studies are rare in scientific labs and essentially missing from clinical environments. PMID:24815984

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

    SciTech Connect

    Peregrin, J. H.; 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 graft 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.

  2. Functions of delay-period activity in the prefrontal cortex and mnemonic scotomas revisited

    PubMed Central

    Funahashi, Shintaro

    2015-01-01

    Working memory (WM) is one of key concepts to understand functions of the prefrontal cortex. Delay-period activity is an important neural correlate to understand the role of WM in prefrontal functions. The importance of delay-period activity is that this activity can encode not only visuospatial information but also a variety of information including non-spatial visual features, auditory and tactile stimuli, task rules, expected reward, and numerical quantity. This activity also participates in a variety of information processing including sensory-to-motor information transformation. These mnemonic features of delay-period activity enable to perform various important operations that the prefrontal cortex participates in, such as executive controls, and therefore, support the notion that WM is an important function to understand prefrontal functions. On the other hand, although experiments using manual versions of the delayed-response task had revealed many important findings, an oculomotor version of this task enabled us to use multiple cue positions, exclude postural orientation during the delay period, and further prove the importance of mnemonic functions of the prefrontal cortex. In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. This result indicates that memories for visuospatial coordinates in each hemifield are processed primarily in the contralateral prefrontal cortex. This result further strengthened the idea of mnemonic functions of the prefrontal cortex. Thus, the mnemonic functions of the prefrontal cortex and delay-period activity may not need to be reconsidered, but should be emphasized. PMID:25698942

  3. Functions of delay-period activity in the prefrontal cortex and mnemonic scotomas revisited.

    PubMed

    Funahashi, Shintaro

    2015-01-01

    Working memory (WM) is one of key concepts to understand functions of the prefrontal cortex. Delay-period activity is an important neural correlate to understand the role of WM in prefrontal functions. The importance of delay-period activity is that this activity can encode not only visuospatial information but also a variety of information including non-spatial visual features, auditory and tactile stimuli, task rules, expected reward, and numerical quantity. This activity also participates in a variety of information processing including sensory-to-motor information transformation. These mnemonic features of delay-period activity enable to perform various important operations that the prefrontal cortex participates in, such as executive controls, and therefore, support the notion that WM is an important function to understand prefrontal functions. On the other hand, although experiments using manual versions of the delayed-response task had revealed many important findings, an oculomotor version of this task enabled us to use multiple cue positions, exclude postural orientation during the delay period, and further prove the importance of mnemonic functions of the prefrontal cortex. In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. This result indicates that memories for visuospatial coordinates in each hemifield are processed primarily in the contralateral prefrontal cortex. This result further strengthened the idea of mnemonic functions of the prefrontal cortex. Thus, the mnemonic functions of the prefrontal cortex and delay-period activity may not need to be reconsidered, but should be emphasized.

  4. A functional analysis of verbal delay in preschool children: Implications for prevention and total recovery

    PubMed Central

    Drash, Philip W.; Tudor, Roger M.

    1993-01-01

    Delays in acquiring age-appropriate verbal repertoires in preschool children with no known organic etiology may be explained by defective or absent behavior-environmental contingencies. This paper presents six possible behavioral paradigms that describe verbal episodes between parents and their preschool children and how these interactions may inhibit or prevent the acquisition of verbal behavior. These paradigms are contrasted with parent-child interactions that typically result in age-appropriate verbal repertoires. Identifying the reinforcement contingencies that produce delays in acquisition of verbal behavior could lead to the development of more effective behavioral programs for remediating nonorganic language delay. Recommendations for prevention, treatment and total recovery from functional verbal delay and associated mental retardation are presented. The relation between contingency-shaped and rule-governed behavior in the shaping of verbal behavior is discussed. PMID:22477077

  5. The first case of atrial fibrillation-related graft kidney infarction following acute pyelonephritis.

    PubMed

    Tsai, Shang-Feng

    2014-01-01

    Native renal infarction is uncommon in patients with atrial fibrillation (AF)-related thromboembolism. Graft infarction is also rare, with such cases mostly occurring in the main graft artery postoperatively. To date, there have been no studies of AF-related graft kidney infarction. We herein describe the first case of AF-related graft kidney infarction. The clinical manifestations of this condition mimic and follow those of acute pyelonephritis; therefore, these diseases should be differentially diagnosed as early as possible using lactic dehydrogenase testing and computed tomography. Aggressive treatment with intravascular thrombolysis should be administered, even when the diagnosis is delayed, in order to restore a viable renal function.

  6. Metabolic risk factors and long-term graft function after paediatric renal transplantation.

    PubMed

    Tainio, Juuso; Qvist, Erik; Hölttä, Tuula; Pakarinen, Mikko; Jahnukainen, Timo; Jalanko, Hannu

    2014-06-01

    The aim of this study was to evaluate metabolic risk factors and their impact on long-term allograft function in paediatric renal transplant (RTx) patients. We reviewed the medical records of 210 RTx patients who underwent transplantation at a median age of 4.5 years (range 0.7-18.2) and a median follow-up of 7.0 years (range 1.5-18.0). Data on lipid and glucose metabolism, uric acid levels, weight and blood pressure were collected up to 13 years post-RTx, and the findings were correlated with the measured glomerular filtration rate (GFR). Beyond the first year, GFR showed gradual deterioration with a mean decline of 2.4 ml/min/1.73 m(2)/year. Metabolic syndrome, overweight, hypertension and type 2 diabetes were diagnosed in 14-19%, 20-23%, 62-87% and 3-5% of the patients, respectively. These entities showed only mild association with the concomitant or long-term GFR values. Dyslipidaemia was common and hypertriglyceridaemia associated with a lower GFR at 1.5 and 5 years post-RTx (P = 0.008 and P = 0.017, respectively). Similarly, hyperuricaemia was frequent and associated significantly with GFR (P < 0.001). Except for hyperuricaemia and hypertriglyceridaemia, metabolic risk factors beyond the first postoperative year associated modestly with the long-term kidney graft function in paediatric RTx patients.

  7. Adsorption of Co(II) by a carboxylate-functionalized polyacrylamide grafted lignocellulosics.

    PubMed

    Shibi, I G; Anirudhan, T S

    2005-02-01

    A new adsorbent (PGBS-COOH) having carboxylate functional group at the chain end was synthesized by graft copolymerization of acrylamide onto banana stalk, BS (Musa Paradisiaca) using ferrous ammonium sulphate/H2O2 redox initiator system. The efficiency of the adsorbent in the removal of cobalt [Co(II)] from water was investigated using batch adsorption technique. The adsorbent exhibits very high adsorption potential for Co(II) and under optimum conditions more than 99% removal was achieved. The maximum adsorption capacity was observed at the pH range 6.5-9.0. The equilibrium isotherm data were analysed using three isotherm models, Langmuir, Freundlich and Scatchard, to determine the best fit equation for the sorption of Co(II) on the PGBS-COOH. A comparative study with a commercial cation exchanger, Ceralite IRC-50, having carboxylate functional group showed that PGBS-COOH is 2.8 times more effective compared to Ceralite IRC-50 at 30 degrees C. Synthetic nuclear power plant coolant water samples were also treated by the adsorbent to demonstrate its efficiency in removing Co(II) from water in the presence of other metal ions. Acid regeneration was tried for several cycles to recover the adsorbed metal ions and also to restore the sorbent to its original state.

  8. Statistics of time delay and scattering correlation functions in chaotic systems. I. Random matrix theory

    SciTech Connect

    Novaes, Marcel

    2015-06-15

    We consider the statistics of time delay in a chaotic cavity having M open channels, in the absence of time-reversal invariance. In the random matrix theory approach, we compute the average value of polynomial functions of the time delay matrix Q = − iħS{sup †}dS/dE, where S is the scattering matrix. Our results do not assume M to be large. In a companion paper, we develop a semiclassical approximation to S-matrix correlation functions, from which the statistics of Q can also be derived. Together, these papers contribute to establishing the conjectured equivalence between the random matrix and the semiclassical approaches.

  9. Delayed Liver Function Impairment Secondary to Interferon β-1a Use in Multiple Sclerosis

    PubMed Central

    Liao, Ming-Feng; Yen, Su-Chen; Chun-Yen, Lin; Rong-Kuo, Lyu

    2013-01-01

    Interferon β-1a is a widely used immunomodulation treatment for multiple sclerosis. Liver function impairment is a common side effect and usually develops in the first 6 months after interferon use. Here, we describe 2 multiple sclerosis patients who developed delayed liver function impairment 5 years after receiving interferon β-1a treatment. Their liver function recovered after discontinuing interferon use, and further detailed hepatological evaluations excluded other etiologies of liver function impairment. Our case reports illustrate that liver function impairment induced by interferon β-1a can be delayed for 5 years after starting treatment and, probably, this is an idiosyncratic reaction. Regular liver function monitoring in multiple sclerosis patients who receive interferon β is necessary even after the first 6 months of treatment, especially in those patients with concomitant use of other liver-toxic medications. PMID:23904853

  10. Rapid Functional Decline of Activated and Memory Graft-vs-Host-Reactive T Cells Encountering Host Antigens in the Absence of Inflammation

    PubMed Central

    Li, Hao Wei; Andreola, Giovanna; Carlson, Alicia; Shao, Steven; Lin, Charles; Zhao, Guiling; Sykes, Megan

    2015-01-01

    Inflammation in the priming host environment has critical effects on the graft-vs-host (GVH) responses mediated by naïve donor T cells. However, it is unclear how a quiescent or inflammatory environment impacts the activity of GVH-reactive primed T and memory cells. We show here that GVH-reactive primed donor T cells generated in irradiated recipients had diminished ability compared to naïve T cells to increase donor chimerism when transferred to quiescent mixed allogeneic chimeras. GVH-reactive primed T cells showed marked loss of cytotoxic function and activation and delayed but not decreased proliferation or accumulation in lymphoid tissues when transferred to quiescent mixed chimeras compared to freshly irradiated secondary recipients. Primed CD4 and CD8 T cells provided mutual help to sustain these functions in both subsets. CD8 help for CD4 cells was largely IFN-γ-dependent. Toll-like receptor (TLR) stimulation following transfer of GVH-reactive primed T cells to mixed chimeras restored their cytotoxic effector function and permitted the generation of more effective T cell memory in association with reduced PD-1 expression on CD4 memory cells. Our data indicate that an inflammatory host environment is required for the maintenance of GVH-reactive primed T cell functions and the generation of memory T cells that can rapidly acquire effector functions. These findings have important implications for GVHD and T cell-mediated immunotherapies. PMID:26085679

  11. 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

  12. Effect of coronary artery bypass graft surgery on left ventricular systolic function

    PubMed Central

    Koene, Ryan J.; Kealhofer, Jessica V.; Adabag, Selcuk; Vakil, Kairav

    2017-01-01

    Background Changes in left ventricular (LV) systolic function in response to coronary artery bypass grafting (CABG) have not been fully assessed. Methods Between January 2001 and December 2014, 2,838 consecutive patients underwent isolated CABG at the Minneapolis Veterans Affairs Health Care System. Of these, 375 had echocardiographic assessment of LV function before (within 6 months) and after (3 to 24 months) CABG and were included in this analysis. Results While the mean LV ejection fraction (LVEF) did not change following CABG [(49±13)% vs. (49±12)%, P=0.51], LVEF decreased in the subgroup with normal (≥50%) pre-operative LVEF [from (59±5)% to (56±9)%, P<0.001] and improved in those with decreased (<50%) pre-operative LVEF [from (36±9)% to (41±12)%, P<0.001]. There was a significant reduction in LV internal diameter during end-diastole (LVIDd) (5.4±0.8 vs. 5.3±0.9, P=0.002) and an increase in left atrial diameter (LAD) (4.4±0.7 vs. 4.6±0.7, P<0.001). There were no perioperative changes in LV internal diameter during end-systole, LV mass, posterior wall thickness, or septal wall thickness. LVEF improved by >5% in 24% of the study population, did not change (+/− 5%) in 55%, and worsened by >5% in 21%. Patients with improved EF were less often diabetic and had lower pre-operative LVEF, and greater LV dimensions at baseline. Conclusions After CABG, there was a decrease in LVIDd and an increase in LAD. Also, a decrease in LV systolic function with CABG was observed in patients with normal pre-operative LVEF and an improvement in LV systolic function was observed in patients with decreased pre-operative LVEF. PMID:28275473

  13. Adaptive modified function projective synchronization of multiple time-delayed chaotic Rossler system

    NASA Astrophysics Data System (ADS)

    Sudheer, K. Sebastian; Sabir, M.

    2011-02-01

    In this Letter we consider modified function projective synchronization of unidirectionally coupled multiple time-delayed Rossler chaotic systems using adaptive controls. Recently, delay differential equations have attracted much attention in the field of nonlinear dynamics. The high complexity of the multiple time-delayed systems can provide a new architecture for enhancing message security in chaos based encryption systems. Adaptive control can be used for synchronization when the parameters of the system are unknown. Based on Lyapunov stability theory, the adaptive control law and the parameter update law are derived to make the state of two chaotic systems are function projective synchronized. Numerical simulations are presented to demonstrate the effectiveness of the proposed adaptive controllers.

  14. Biocompatibility and functional performance of a polyethylene glycol acid-grafted cellulosic membrane for hemodialysis.

    PubMed

    Sirolli, V; Di Stante, S; Stuard, S; Di Liberato, L; Amoroso, L; Cappelli, P; Bonomini, M

    2000-06-01

    In order to improve the biochemical reactivity of the cellulose polymer, which is mainly attributed to the presence of surface hydroxyl groups, derivatized cellulosic membranes have been engineered replacing or masking some or all of the hydroxyl groups in the manufacturing process of the membrane. The present study was set up to analyze both biocompatibility and functional performance of two different derivatized cellulosic membranes (cellulose diacetate; polyethylene glycol, PEG, acid-grafted cellulose) as compared to a synthetic membrane (polymethylmethacrylate, PMMA). Cellulose diacetate is prepared by substituting hydroxyl groups with acetyl groups; PEG cellulose is obtained by grafting PEG chains onto the cellulosic polymer with a smaller amount of substitution than cellulose diacetate. While the three dialyzers provided similar urea and creatinine removal, the dialyzer containing cellulose diacetate showed a reduced ability to remove 32-microglobulin compared to that containing PEG cellulose or PMMA. A transient reduction in leukocyte count was observed for both derivatized cellulosic membranes. The neutrophil and monocyte counts throughout the entire dialysis session showed a closer parallelism with the cellular expression of the adhesive receptor CD 15s (sialyl-Lewis x molecule) than with CD11b/CD18 expression. Platelet activation, as indicated by the percentage of cells expressing the activation markers CD62P (P-selectin) and CD63 (gp53), occurred with all membranes at 15 min of dialysis and also with PMMA at 30 min. An increased formation of platelet-neutrophil and platelet-monocyte coaggregates was found at 15 and 30 min during dialysis with cellulose diacetate and PMMA but not with PEG cellulose. Generally in concomitance with the increase in platelet-neutrophil coaggregates, an increased hydrogen peroxide production by neutrophils occurred. Our results indicate that derivatizing cellulose may represent a useful approach to improve the biocompatibility

  15. Emergency coronary bypass grafting for evolving myocardial infarction. Effects on infarct size and left ventricular function

    SciTech Connect

    Flameng, W.; Sergeant, P.; Vanhaecke, J.; Suy, R.

    1987-07-01

    Emergency aorta-coronary bypass grafting was performed early in the course of evolving myocardial infarction in 48 patients. The time interval between the onset of symptoms and reperfusion was 169 +/- 80 minutes. Quantitative assessment of postoperative thallium 201 myocardial scans in 19 patients revealed a significant salvage of myocardium after surgical reperfusion: The size of the residual infarction was less than 50% of that in a matched, medically treated, prospective control group (n = 39) (p less than 0.05). Postoperative equilibrium-gated radionuclide blood pool studies (technetium 99m) showed an enhanced recovery of regional and global ejection fraction after operation as compared to after medical treatment (p less than 0.05). Ultrastructural evaluation of biopsy specimens obtained during the operation delineated subendocardial necrosis in the majority of cases (72%), but subepicardial necrosis was found in only 6% of instances. Q-wave abnormalities were observed on the postoperative electrocardiogram in 50% of cases. Operative mortality was 0% in low-risk patients (i.e., hemodynamically stable condition, n = 26) and 18% in high-risk patients (i.e., cardiogenic shock including total electromechanical dysfunction, n = 22). Survival rate at 18 months was 92% +/- 4%, and 95% +/- 4% of the survivors were event free. It is concluded that early surgical reperfusion of evolving myocardial infarction limits infarct size significantly, enhances functional recovery, and may be a lifesaving operation in patients having cardiogenic shock associated with unsuccessful resuscitation.

  16. Examining Relationships between Executive Functioning and Delay Aversion in Attention Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Karalunas, Sarah L.; Huang-Pollock, Cynthia L.

    2011-01-01

    Although motivation and cognition are often examined separately, recent theory suggests that a delay-averse motivational style may negatively impact development of executive functions (EFs), such as working memory (WM) and response inhibition (RI) for children with Attention Deficit Hyperactivity Disorder (ADHD; Sonuga-Barke, 2002). This model…

  17. Effects of Methylphenidate and Morphine on Delay-Discount Functions Obtained within Sessions

    ERIC Educational Resources Information Center

    Pitts, Raymond C.; McKinney, A. Patrick

    2005-01-01

    Four rats responded under a "self-control" procedure designed to obtain delay- discount functions within sessions. Each session consisted of seven blocks, with seven trials within each block. Each block consisted of two initial forced- choice trials followed by five free-choice trials. On choice trials, the rats could press either of two…

  18. Urinary CD133+ Extracellular Vesicles Are Decreased in Kidney Transplanted Patients with Slow Graft Function and Vascular Damage

    PubMed Central

    Dimuccio, Veronica; Ranghino, Andrea; Praticò Barbato, Loredana; Fop, Fabrizio; Biancone, Luigi; Camussi, Giovanni; Bussolati, Benedetta

    2014-01-01

    Extracellular vesicles (EVs) present in the urine are mainly released from cells of the nephron and can therefore provide information on kidney function. We here evaluated the presence of vesicles expressing the progenitor marker CD133 in the urine of normal subjects and of patients undergoing renal transplant. We found that EV expressing CD133 were present in the urine of normal subjects, but not of patients with end stage renal disease. The first day after transplant, urinary CD133+ EVs were present at low levels, to increase thereafter (at day 7). Urinary CD133+ EVs significantly increased in patients with slow graft function in respect to those with early graft function. In patients with a severe pre-transplant vascular damage of the graft, CD133+ EVs did not increase at day 7. At variance, the levels of EVs expressing the renal exosomal marker CD24 did not vary in the urine of patients with end stage renal disease or in transplanted patients in respect to controls. Sorted CD133+ EVs were found to express glomerular and proximal tubular markers. These data indicate that urinary CD133+ EVs are continuously released during the homeostatic turnover of the nephron and may provide information on its function or regenerative potential. PMID:25100147

  19. Improvement of islet graft function using liraglutide is correlated with its anti‐inflammatory properties

    PubMed Central

    Langlois, A; Dal, S; Vivot, K; Mura, C; Seyfritz, E; Bietiger, W; Dollinger, C; Peronet, C; Maillard, E; Pinget, M; Jeandidier, N

    2016-01-01

    Background and Purpose Liraglutide improves the metabolic control of diabetic animals after islet transplantation. However, the mechanisms underlying this effect remain unknown. The objective of this study was to evaluate the anti‐inflammatory and anti‐oxidative properties of liraglutide on rat pancreatic islets in vitro and in vivo. Experimental Approach In vitro, rat islets were incubated with 10 μmol·L−1 liraglutide for 12 and 24 h. Islet viability functionality was assessed. The anti‐inflammatory properties of liraglutide were evaluated by measuring CCL2, IL‐6 and IL‐10 secretion and macrophage chemotaxis. The anti‐oxidative effect of liraglutide was evaluated by measuring intracellular ROS and the total anti‐oxidative capacity. In vivo, 1000 islets were cultured for 24 h with or without liraglutide and then transplanted into the liver of streptozotocin‐induced diabetic Lewis rats with or without injections of liraglutide. Effects of liraglutide on metabolic control were evaluated for 1 month. Key Results Islet viability and function were preserved and enhanced with liraglutide treatment. Liraglutide decreased CCL2 and IL‐6 secretion and macrophage activation after 12 h of culture, while IL‐10 secretion was unchanged. However, intracellular levels of ROS were increased with liraglutide treatment at 12 h. This result was correlated with an increase of anti‐oxidative capacity. In vivo, liraglutide decreased macrophage infiltration and reduced fasting blood glucose in transplanted rats. Conclusions and Implications The beneficial effects of liraglutide on pancreatic islets appear to be linked to its anti‐inflammatory and anti‐oxidative properties. These findings indicated that analogues of glucagon‐like peptide‐1 could be used to improve graft survival. PMID:27515367

  20. Bone graft

    MedlinePlus

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

  1. Exponential stability of delayed and impulsive cellular neural networks with partially Lipschitz continuous activation functions.

    PubMed

    Song, Xueli; Xin, Xing; Huang, Wenpo

    2012-05-01

    The paper discusses exponential stability of distributed delayed and impulsive cellular neural networks with partially Lipschitz continuous activation functions. By relative nonlinear measure method, some novel criteria are obtained for the uniqueness and exponential stability of the equilibrium point. Our method abandons usual assumptions on global Lipschitz continuity, boundedness and monotonicity of activation functions. Our results are generalization and improvement of some existing ones. Finally, two examples and their simulations are presented to illustrate the correctness of our analysis.

  2. Global asymptotical stability of continuous-time delayed neural networks without global Lipschitz activation functions

    NASA Astrophysics Data System (ADS)

    Tan, Yong; Tan, Mingjia

    2009-11-01

    This paper investigates the global asymptotic stability of equilibrium for a class of continuous-time neural networks with delays. Based on suitable Lyapunov functionals and the homeomorphism theory, some sufficient conditions for the existence and uniqueness of the equilibrium point are derived. These results extend the previously works without assuming boundedness and Lipschitz conditions of the activation functions and any symmetry of interconnections. A numerical example is also given to show the improvements of the paper.

  3. Bifurcation and Stability in a Delayed Predator-Prey Model with Mixed Functional Responses

    NASA Astrophysics Data System (ADS)

    Yafia, R.; Aziz-Alaoui, M. A.; Merdan, H.; Tewa, J. J.

    2015-06-01

    The model analyzed in this paper is based on the model set forth by Aziz Alaoui et al. [Aziz Alaoui & Daher Okiye, 2003; Nindjin et al., 2006] with time delay, which describes the competition between the predator and prey. This model incorporates a modified version of the Leslie-Gower functional response as well as that of Beddington-DeAngelis. In this paper, we consider the model with one delay consisting of a unique nontrivial equilibrium E* and three others which are trivial. Their dynamics are studied in terms of local and global stabilities and of the description of Hopf bifurcation at E*. At the third trivial equilibrium, the existence of the Hopf bifurcation is proven as the delay (taken as a parameter of bifurcation) that crosses some critical values.

  4. The graft-versus-host reaction and immune function. I. T helper cell immunodeficiency associated with graft-versus-host-induced thymic epithelial cell damage

    SciTech Connect

    Seddik, M.; Seemayer, T.A.; Lapp, W.S.

    1984-03-01

    The injection of parental A strain lymphoid cells into adrenalectomized CBAxA F1 (BAF1) mice induced a chronic graft-versus-host (GVH) reaction resulting in T cell and B cell immunosuppression as well as thymic epithelial cell injury, but not stress-related thymic involution. Thymocytes from BAF1 mice undergoing a GVH reaction were studied for their ability to reconstitute T helper cell (TH) function and phytohemagglutinin (PHA) and concanavalin A (Con A) mitogen responses in thymectomized, irradiated, BAF1 mice reconstituted with normal syngeneic bone marrow (ATxBM). Thymocytes from BAF1 mice early after the induction of a GVH reaction (days 10-12) were as effective as normal thymocytes in reconstituting TH and mitogen responses. Thymocytes from BAF1 mice 40 or more days after the induction of a GVH reaction did not reconstitute either the TH function or PHA and Con A responses in ATxBM mice. The inability to reconstitute ATxBM mice was not due to the presence of suppressor cells contained in the thymocyte inoculum. It is proposed that GVH-induced thymic epithelial cell injury blocks or arrests normal T cell differentiation, resulting in a population of thymocytes that lack the potential to become competent T helper cells or mitogen-responsive cells when transferred into ATxBM mice. This thymic functional defect results in a permanent TH immunodeficiency in mice experiencing a chronic GVH reaction.

  5. An effective non-covalent grafting approach to functionalize individually dispersed reduced graphene oxide sheets with high grafting density, solubility and electrical conductivity

    NASA Astrophysics Data System (ADS)

    Wang, Hao; Bi, Shu-Guang; Ye, Yun-Sheng; Xue, Yang; Xie, Xiao-Lin; Mai, Yiu-Wing

    2015-02-01

    Polymer-functionalized reduced graphene oxide (polymer-FG), produced as individually dispersed graphene sheets, offers new possibilities for the production of nanomaterials that are useful for a broad range of potential applications. Although non-covalent functionalization has produced graphene with good dispersibility and a relatively complete conjugated network, there are few reports related to the effective functionalization of reduced graphene oxide (RGO) using a simple, general method. Herein, we report a facile and effective approach for the preparation of polymer-FG from a non-covalently functionalized pyrene-terminal polymer in benzoyl alcohol (BnOH). This aromatic alcohol (BnOH) was used as the liquid medium for the dispersion of graphene oxide (GO) with a pyrene-terminal polymer, and as an effective reductant; this makes the synthesis procedure convenient and the production of polymer-FG easily scalable because the conversion of GO to RGO and the non-covalent functionalization proceed simultaneously. The resulting polymer-FG sheets show organo-dispersibility, high electrical conductivity and good processability, and have a similar grafting density comparable to covalently made materials, thus making them promising candidates for applications such as electrochemical devices, nanomaterials and polymer nanocomposites. Hence, this work provides a general methodology for preparing individually dispersed graphene sheets with desirable properties.Polymer-functionalized reduced graphene oxide (polymer-FG), produced as individually dispersed graphene sheets, offers new possibilities for the production of nanomaterials that are useful for a broad range of potential applications. Although non-covalent functionalization has produced graphene with good dispersibility and a relatively complete conjugated network, there are few reports related to the effective functionalization of reduced graphene oxide (RGO) using a simple, general method. Herein, we report a facile

  6. Monitoring the Intracellular Tacrolimus Concentration in Kidney Transplant Recipients with Stable Graft Function.

    PubMed

    Han, Seung Seok; Yang, Seung Hee; Kim, Min Chang; Cho, Joo-Youn; Min, Sang-Il; Lee, Jung Pyo; Kim, Dong Ki; Ha, Jongwon; Kim, Yon Su

    2016-01-01

    Although monitoring the intracellular concentration of immunosuppressive agents may be a promising approach to individualizing the therapy after organ transplantation, additional studies on this issue are needed prior to its clinical approval. We investigated the relationship between intracellular and whole blood concentrations of tacrolimus (IC-TAC and WB-TAC, respectively), the factors affecting this relationship, and the risk of rejection based upon IC-TAC in stable kidney recipients. Both IC-TAC and WB-TAC were measured simultaneously in 213 kidney recipients with stable graft function using LC-MS/MS. The tacrolimus ratio was defined as IC-TAC per WB-TAC. The genetic polymorphism of ABCB1 gene and flow cytometric analyses were conducted to probe the correlation between tacrolimus concentrations and the immunoreactivity status as a potential risk of rejection, respectively. The correlation between IC-TAC and WB-TAC was relatively linear (r = 0.67; P<0.001). The factors affecting the tacrolimus ratio were sex, hematocrit, and the transplant duration, as follows: a high tacrolimus ratio was noted in female patients, patients with a low hematocrit, and patients with a short transplant period. However, the tacrolimus ratio did not reflect the prior clinical outcomes (e.g., rejection) or the genetic polymorphism of ABCB1. After stimulation with phorbol-12-myristate 13-acetate and ionomycin, the proportion of T cells producing interferon-gamma or interleukin-2 was higher in the low-IC-TAC group than in the high-IC-TAC group. Further studies are required to evaluate the value of the intracellular tacrolimus concentrations in several clinical settings, such as rejection, infection, and drug toxicity.

  7. Metallic Fixation of Mandibular Segmental Defects: Graft Immobilization and Orofacial Functional Maintenance

    PubMed Central

    Shayesteh Moghaddam, Narges; Jahadakbar, Ahmadreza; Amerinatanzi, Amirhesam; Elahinia, Mohammad; Miller, Michael

    2016-01-01

    Background: The aim of this study is to investigate the behavior of the healthy mandible under maximum molar bite force to demonstrate the problems associated with the current standard of care procedures for mandibular segmental defect reconstruction (ie, use of Ti–6Al–4V hardware and either a single- or double-barrel fibular graft). With current Ti–6Al–4V mandibular reconstruction hardware, there is a significant stiffness mismatch among the hardware, graft, and the remaining host anatomy. How the distribution of mechanical forces through the mandible is altered after a segmental bone loss and reconstruction is incompletely understood. Methods: We studied a healthy adult mandible for stress, strain, and reaction force distribution during normal mastication. Stress distribution of this model was then used to study problems encountered after mandibular segmental defect reconstructive surgery. We model the use of both single- and double-barrel fibular grafts to repair the loss of the left M1–3 containing segment of the mandible. These simulations were done using 2 sets of plates with different thicknesses. Results: We found that the stiffness mismatching between the fixation hardware and the graft and host bone causes stress shielding of that bone and stress concentrations in the fixation hardware and screws. These effects are expected, especially during the bone healing period. However, long term, this abnormal stress–strain distribution may lead to either the hardware’s failure due to stress concentration or graft failure due to bone resorption as a result of stress shielding. We found that the stress–strain distribution is more normal with a double-barrel fibular graft. Additionally, we found that thinner fixation plates can reduce stress shielding. Conclusion: The proposed model can be used to evaluate the performance and optimization of the fixation device. PMID:27757323

  8. Adaptive Function in Preschoolers in Relation to Developmental Delay and Diagnosis of Autism Spectrum Disorders: Insights from a Clinical Sample

    ERIC Educational Resources Information Center

    Milne, Susan L.; McDonald, Jenny L.; Comino, Elizabeth J.

    2013-01-01

    This study aims to explore the relationship between developmental ability, autism and adaptive skills in preschoolers. Adaptive function was assessed in 152 preschoolers with autism, with and without developmental delay, and without autism, with and without developmental delay. Their overall adaptive function, measured by the general adaptive…

  9. Chemical reactions in dense monolayers: in situ thermal cleavage of grafted esters for preparation of solid surfaces functionalized with carboxylic acids.

    PubMed

    Dugas, Vincent; Chevalier, Yves

    2011-12-06

    The thermodynamics of a chemical reaction confined at a solid surface was investigated through kinetic measurements of a model unimolecular reaction. The thermal cleavage of ester groups grafted at the surface of solid silica was investigated together with complementary physicochemical characterization of the grafted species. The ester molecules were chemically grafted to the silica surface and subsequently cleaved into the carboxylic acids. A grafting process of a reproducible monolayer was designed using the reaction of monofunctional organosilane from its gas phase. The thermal deprotection step of the ester end-group was investigated. The thermal deprotection reaction behaves in quite a specific manner when it is conducted at a surface in a grafted layer. Different organosilane molecules terminated by methyl, isopropyl and tert-butyl ester groups were grafted to silica surface; such functionalized materials were characterized by elemental analysis, IR and NMR spectroscopy, and thermogravimetric analysis, and the thermodynamic parameters of the thermal elimination reaction at the surface were measured. The limiting factor of such thermal ester cleavage reaction is the thermal stability of grafted ester group according to the temperature order: tert-butyl < i-propyl < methyl. Methyl ester groups were not selectively cleaved by temperature. The thermal deprotection of i-propyl ester groups took place at a temperature close to the thermal degradation of the organofunctional tail of the silane. The low thermolysis temperature of the grafted tert-butyl esters allowed their selective cleavage. There is a definite influence of the surface on the reaction. The enthalpy of activation is lower than in the gas phase because of the polarity of the reaction site. The major contribution is entropic; the negative entropy of activation comes from lateral interactions with the neighbor grafted molecules because of the high grafting density. Such reaction is an original strategy

  10. Bone Graft Substitution and Augmentation.

    PubMed

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

    2015-12-01

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

  11. Oscillations for a delayed predator-prey model with Hassell-Varley-type functional response.

    PubMed

    Xu, Changjin; Li, Peiluan

    2015-04-01

    In this paper, a delayed predator-prey model with Hassell-Varley-type functional response is investigated. By choosing the delay as a bifurcation parameter and analyzing the locations on the complex plane of the roots of the associated characteristic equation, the existence of a bifurcation parameter point is determined. It is found that a Hopf bifurcation occurs when the parameter τ passes through a series of critical values. The direction and the stability of Hopf bifurcation periodic solutions are determined by using the normal form theory and the center manifold theorem due to Faria and Maglhalaes (1995). In addition, using a global Hopf bifurcation result of Wu (1998) for functional differential equations, we show the global existence of periodic solutions. Some numerical simulations are presented to substantiate the analytical results. Finally, some biological explanations and the main conclusions are included.

  12. Spontaneous Rupture of Superficial Femoral Artery Repaired with Endovascular Stent-Grafting with use of Rendez-Vous Technique, Followed by Delayed Infection

    SciTech Connect

    Fanelli, Fabrizio Cannavale, Alessandro; Gazzetti, Marianna; Fantozzi, Cristiano; Taurino, Maurizio; Speziale, Francesco

    2013-02-15

    This is the case of a 72-year-old man with lower limb ischemia due to spontaneous rupture of nonaneurysmal superficial femoral artery that developed into thigh hematoma. After failure of a Fogarty revascularization, an emergency endovascular procedure was performed to restore the arterial continuity. A rendezvous procedure was performed with a double femoral and popliteal approach and two covered stent-grafts were deployed. Patient's clinical conditions immediately improved, but 4 months later the stent-grafts were surgically removed for infection and exteriorization. A femoropopliteal bypass was performed. After 1 year follow-up, the patient is in good clinical condition.

  13. Loss of B cell regulatory function is associated with delayed healing in patients with tibia fracture.

    PubMed

    Yang, Shufeng; Ding, Wei; Feng, Dapeng; Gong, Haiyang; Zhu, Dongmei; Chen, Bin; Chen, Jianmin

    2015-11-01

    The process of bone regeneration after fracture is a complex and well-orchestrated process usually requiring 3-12 weeks. A subset of patients, however, exhibit delayed healing time and even incomplete restoration of the normal bone structure. Although the precise mechanism is unknown, studies have shown that smurf1 may play a role during the process. Here, we sought to determine the involvement of the immune system in impaired bone healing. We found that immediately after fracture, the B-cell composition was shifted toward increased frequency of plasmablasts and decreased frequency of naïve B cells, reflecting higher inflammatory status. The percentage of CD19(+) CD24(+) CD38(+) regulatory B cells was also upregulated in response to bone fracture. The production of IL-10, a pivotal cytokine in regulatory B-cell function, was upregulated in all patients. Interestingly, the increase in IL-10 production was only sustained throughout the healing course in normal healing patients but not in delayed healing patients. Rather, delayed healing patients downregulated B-cell IL-10 secretion early and had reduced level of regulatory B-cell activity. Together, these data revealed a role of regulatory B cells in the endogenous bone regeneration process and an alternation in B-cell-mediated regulation in delayed healing patients.

  14. Sweet graphene I: toward hydrophilic graphene nanosheets via click grafting alkyne-saccharides onto azide-functionalized graphene oxide.

    PubMed

    Namvari, Mina; Namazi, Hassan

    2014-09-19

    Water-soluble graphene nanosheets (GNS) were fabricated via functionalization of graphene oxide (GO) with mono and disaccharides on the basal plane and edges using Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of azides and terminal alkynes (Click chemistry). To graft saccharides onto the plane of GO, it was reacted with sodium azide to introduce azide groups on the plane. Then, it was treated with alkyne-modified glucose, mannose, galactose, and maltose. In the next approach, we attached 1,3-diazideoprop-2-ol onto the edges of GO and it was subsequently clicked with alkyne-glucose. The products were analyzed by Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy, thermogravimetric analysis (TGA), and X-ray diffraction spectrometry. FTIR and TGA results showed both sugar-grafted GO sheets were reduced by sodium ascorbate during click-coupling reaction which is an advantage for this reaction. Besides, glycoside-grafted GNS were easily dispersed in water and stable for two weeks.

  15. Impact of Intensive Physiotherapy on Cognitive Function after Coronary Artery Bypass Graft Surgery.

    PubMed

    Cavalcante, Elder Dos Santos; Magario, Rosmeiri; Conforti, César Augusto; Cipriano Júnior, Gerson; Arena, Ross; Carvalho, Antonio Carlos C; Buffolo, Enio; Luna Filho, Bráulio

    2014-11-01

    Background: Coronary artery bypass graft (CABG) is a standard surgical option for patients with diffuse and significant arterial plaque. This procedure, however, is not free of postoperative complications, especially pulmonary and cognitive disorders. Objective: This study aimed at comparing the impact of two different physiotherapy treatment approaches on pulmonary and cognitive function of patients undergoing CABG. Methods: Neuropsychological and pulmonary function tests were applied, prior to and following CABG, to 39 patients randomized into two groups as follows: Group 1 (control) - 20 patients underwent one physiotherapy session daily; and Group 2 (intensive physiotherapy) - 19 patients underwent three physiotherapy sessions daily during the recovery phase at the hospital. Non-paired and paired Student t tests were used to compare continuous variables. Variables without normal distribution were compared between groups by using Mann-Whitney test, and, within the same group at different times, by using Wilcoxon test. The chi-square test assessed differences of categorical variables. Statistical tests with a p value ≤ 0.05 were considered significant. Results: Changes in pulmonary function were not significantly different between the groups. However, while Group 2 patients showed no decline in their neurocognitive function, Group 1 patients showed a decline in their cognitive functions (P ≤ 0.01). Conclusion: Those results highlight the importance of physiotherapy after CABG and support the implementation of multiple sessions per day, providing patients with better psychosocial conditions and less morbidity.Fundamento: A cirurgia de revascularização miocárdica (CRM) é a opção cirúrgica padrão para pacientes com placas arteriais difusas e significativas. Tal procedimento, no entanto, não é desprovido de complicações pós-operatórias, especialmente distúrbios pulmonares e cognitivos. Objetivo: Comparar o impacto de duas abordagens fisioterap

  16. Use of meixner functions in estimation of Volterra kernels of nonlinear systems with delay.

    PubMed

    Asyali, Musa H; Juusola, Mikko

    2005-02-01

    Volterra series representation of nonlinear systems is a mathematical analysis tool that has been successfully applied in many areas of biological sciences, especially in the area of modeling of hemodynamic response. In this study, we explored the possibility of using discrete time Meixner basis functions (MBFs) in estimating Volterra kernels of nonlinear systems. The problem of estimation of Volterra kernels can be formulated as a multiple regression problem and solved using least squares estimation. By expanding system kernels with some suitable basis functions, it is possible to reduce the number of parameters to be estimated and obtain better kernel estimates. Thus far, Laguerre basis functions have been widely used in this framework. However, research in signal processing indicates that when the kernels have a slow initial onset or delay, Meixner functions, which can be made to have a slow start, are more suitable in terms of providing a more accurate approximation to the kernels. We, therefore, compared the performance of Meixner functions, in kernel estimation, to that of Laguerre functions in some test cases that we constructed and in a real experimental case where we studied photoreceptor responses of photoreceptor cells of adult fruitflies (Drosophila melanogaster). Our results indicate that when there is a slow initial onset or delay, MBF expansion provides better kernel estimates.

  17. Delayed administration IL-1β neutralizing antibody improves cognitive function after transient global ischemia in rats.

    PubMed

    Zhao, Bei; Zou, Chang-Jiang; Zhou, Ping

    2016-04-15

    In order to study the protective effects on motor and cognitive function by inhibiting IL-1β as delayed as 24h after global ischemia, we designed behavioral testing protocol and histology detection after 10 min transient global ischemia followed by IL-1β or its antibody intracerebroventricular injection. We found benefit of IL-1β antibody treatment 24h after ischemia in cognitive function recovery. But no obvious amelioration in motor function was found. Further we detected cell morphology and survival by histology staining and proved IL-1β antibody could reduce ischemia induced cell morphological changes and cell loss in hippocampus, which related with cognitive function. Present results indicate intervening IL-1β pathway could be helpful in cognitive function recovery even as late as 24h after ischemia happens.

  18. Remember the Future II: Meta-analyses and Functional Overlap of Working Memory and Delay Discounting

    PubMed Central

    Wesley, Michael J.; Bickel, Warren K.

    2013-01-01

    Background Previously we showed that working memory training decreased the discounting of future rewards in stimulant addicts without affecting a Go/NoGo task. While a relationship between delay discounting and working memory is consistent with other studies, the unique brain regions of plausible causality between these two abilities have yet to be determined. Methods Activation likelihood estimation (ALE) meta-analyses were performed on foci from studies of delay discounting (DD = 449), working memory (WM = 452), finger tapping (FT = 450), and response inhibition (RI = 450). Activity maps from relatively less (FT) and more (RI) demanding executive tasks were contrasted with maps of DD and WM. Overlap analysis identified unique functional coincidence between DD and WM. Results The anterior cingulate cortex was engaged by all tasks. FT largely engaged motor-related brain areas. In addition to motor-related areas, RI engaged frontal brain regions. The right lateral prefrontal cortex was engaged by RI, DD and WM and was contrasted out of overlap maps. A functional cluster in the posterior portion of the left lateral prefrontal cortex emerged as the largest location of unique overlap between DD and WM. Conclusions A portion of the left lateral prefrontal cortex is a unique location where delay discounting and working memory processes overlap in the brain. This area, therefore, represents a therapeutic target for improving behaviors that rely on the integration of the recent past with the foreseeable future. PMID:24041504

  19. Delayed video self-recognition in children with high functioning autism and Asperger's disorder.

    PubMed

    Dissanayake, Cheryl; Shembrey, Joh; Suddendorf, Thomas

    2010-09-01

    Two studies are reported which investigate delayed video self-recognition (DSR) in children with autistic disorder and Asperger's disorder relative to one another and to their typically developing peers. A secondary aim was to establish whether DSR ability is dependent on metarepresentational ability. Children's verbal and affective responses to their image were also measured. Three groups of male children between 5 and 9 years, comprising 15 with high-functioning autistic disorder (HFA), 12 with Asperger's disorder (AspD), and 15 typically developing (TD) children, participated in Study 1. Study 2 included two groups of younger children (18 HFA; 18 TD) aged 4 to 7 years. Participant groups in each study were equally able to recognize themselves using delayed video feedback, and responded to their marked image with positive affect. This was so even amongst children with HFA who were impaired in their performance on false belief tasks, casting doubt on a metarepresentational basis of DSR.

  20. Grafts of fetal dopamine neurons survive and improve motor function in Parkinson's disease

    SciTech Connect

    Lindvall, O.; Brundin, P.; Widner, H.; Rehncrona, S.; Gustavii, B.; Frackowiak, R.; Leenders, K.L.; Sawle, G.; Rothwell, J.C.; Marsden, C.D. )

    1990-02-02

    Neural transplantation can restore striatal dopaminergic neurotransmission in animal models of Parkinson's disease. It has now been shown that mesencephalic dopamine neurons, obtained from human fetuses of 8 to 9 weeks gestational age, can survive in the human brain and produce marked and sustained symptomatic relief in a patient severely affected with idiopathic Parkinson's disease. The grafts, which were implanted unilaterally into the putamen by stereotactic surgery, restored dopamine synthesis and storage in the grafted area, as assessed by positron emission tomography with 6-L-({sup 18}F)fluorodopa. This neurochemical change was accompanied by a therapeutically significant reduction in the patient's severe rigidity and bradykinesia and a marked diminuation of the fluctuations in the patient's condition during optimum medication (the on-off phenomenon). The clinical improvement was most marked on the side contralateral to the transplant.

  1. Delayed Imatinib Treatment for Acute Spinal Cord Injury: Functional Recovery and Serum Biomarkers

    PubMed Central

    Finn, Anja; Hao, Jingxia; Wellfelt, Katrin; Josephson, Anna; Svensson, Camilla I.; Wiesenfeld-Hallin, Zsuzsanna; Eriksson, Ulf; Abrams, Mathew

    2015-01-01

    Abstract With no currently available drug treatment for spinal cord injury, there is a need for additional therapeutic candidates. We took the approach of repositioning existing pharmacological agents to serve as acute treatments for spinal cord injury and previously found imatinib to have positive effects on locomotor and bladder function in experimental spinal cord injury when administered immediately after the injury. However, for imatinib to have translational value, it needs to have sustained beneficial effects with delayed initiation of treatment, as well. Here, we show that imatinib improves hind limb locomotion and bladder recovery when initiation of treatment was delayed until 4 h after injury and that bladder function was improved with a delay of up to 24 h. The treatment did not induce hypersensitivity. Instead, imatinib-treated animals were generally less hypersensitive to either thermal or mechanical stimuli, compared with controls. In an effort to provide potential biomarkers, we found serum levels of three cytokines/chemokines—monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-3α, and keratinocyte chemoattractant/growth-regulated oncogene (interleukin 8)—to increase over time with imatinib treatment and to be significantly higher in injured imatinib-treated animals than in controls during the early treatment period. This correlated to macrophage activation and autofluorescence in lymphoid organs. At the site of injury in the spinal cord, macrophage activation was instead reduced by imatinib treatment. Our data strengthen the case for clinical trials of imatinib by showing that initiation of treatment can be delayed and by identifying serum cytokines that may serve as candidate markers of effective imatinib doses. PMID:25914996

  2. Novel stability analysis for recurrent neural networks with multiple delays via line integral-type L-K functional.

    PubMed

    Liu, Zhenwei; Zhang, Huaguang; Zhang, Qingling

    2010-11-01

    This paper studies the stability problem of a class of recurrent neural networks (RNNs) with multiple delays. By using an augmented matrix-vector transformation for delays and a novel line integral-type Lyapunov-Krasovskii functional, a less conservative delay-dependent global asymptotical stability criterion is first proposed for RNNs with multiple delays. The obtained stability result is easy to check and improve upon the existing ones. Then, two numerical examples are given to verify the effectiveness of the proposed criterion.

  3. High interfacial activity of polymers "grafted through" functionalized iron oxide nanoparticle clusters.

    PubMed

    Foster, Lynn M; Worthen, Andrew J; Foster, Edward L; Dong, Jiannan; Roach, Clarissa M; Metaxas, Athena E; Hardy, Clifford D; Larsen, Eric S; Bollinger, Jonathan A; Truskett, Thomas M; Bielawski, Christopher W; Johnston, Keith P

    2014-09-02

    The mechanism by which polymers, when grafted to inorganic nanoparticles, lower the interfacial tension at the oil-water interface is not well understood, despite the great interest in particle stabilized emulsions and foams. A simple and highly versatile free radical "grafting through" technique was used to bond high organic fractions (by weight) of poly(oligo(ethylene oxide) monomethyl ether methacrylate) onto iron oxide clusters, without the need for catalysts. In the resulting ∼1 μm hybrid particles, the inorganic cores and grafting architecture contribute to the high local concentration of grafted polymer chains to the dodecane/water interface to produce low interfacial tensions of only 0.003 w/v % (polymer and particle core). This "critical particle concentration" (CPC) for these hybrid inorganic/polymer amphiphilic particles to lower the interfacial tension by 36 mN/m was over 30-fold lower than the critical micelle concentration of the free polymer (without inorganic cores) to produce nearly the same interfacial tension. The low CPC is favored by the high adsorption energy (∼10(6) kBT) for the large ∼1 μm hybrid particles, the high local polymer concentration on the particles surfaces, and the ability of the deformable hybrid nanocluster cores as well as the polymer chains to conform to the interface. The nanocluster cores also increased the entanglement of the polymer chains in bulk DI water or synthetic seawater, producing a viscosity up to 35,000 cP at 0.01 s(-1), in contrast with only 600 cP for the free polymer. As a consequence of these interfacial and rheological properties, the hybrid particles stabilized oil-in-water emulsions at concentrations as low as 0.01 w/v %, with average drop sizes down to 30 μm. In contrast, the bulk viscosity was low for the free polymer, and it did not stabilize the emulsions. The ability to influence the interfacial activity and rheology of polymers upon grafting them to inorganic particles, including clusters

  4. Solvability of some partial functional integrodifferential equations with finite delay and optimal controls in Banach spaces.

    PubMed

    Ezzinbi, Khalil; Ndambomve, Patrice

    2016-01-01

    In this work, we consider the control system governed by some partial functional integrodifferential equations with finite delay in Banach spaces. We assume that the undelayed part admits a resolvent operator in the sense of Grimmer. Firstly, some suitable conditions are established to guarantee the existence and uniqueness of mild solutions for a broad class of partial functional integrodifferential infinite dimensional control systems. Secondly, it is proved that, under generally mild conditions of cost functional, the associated Lagrange problem has an optimal solution, and that for each optimal solution there is a minimizing sequence of the problem that converges to the optimal solution with respect to the trajectory, the control, and the functional in appropriate topologies. Our results extend and complement many other important results in the literature. Finally, a concrete example of application is given to illustrate the effectiveness of our main results.

  5. Time-series analysis in the medical domain: a study of Tacrolimus administration and influence on kidney graft function.

    PubMed

    Kurbalija, Vladimir; Radovanović, Miloš; Ivanović, Mirjana; Schmidt, Danilo; von Trzebiatowski, Gabriela Lindemann; Burkhard, Hans-Dieter; Hinrichs, Carl

    2014-07-01

    There exists a major concern regarding toxic effects of immunosuppressive medication on the kidney graft during post-transplant care, with observed variation in individual susceptibility to adverse drug effects amongst patients. To date, there has been no possibility to identify susceptible patients prospectively. This study analyzes medical data which includes time series of measures of renal function and trough levels of immunosuppressive drug Tacrolimus, with the main aim of identifying patients susceptible to drug toxicity. We evaluate a plethora of time-series distance measures, determining their appropriateness to the domain based on two criteria: (1) preserving the expected correlations between distances, and (2) ability to detect the expected patterns of interaction between immunosuppressive drug levels and renal function. Besides identifying the most suitable time-series distance measures, we observed that the majority of patients do not exhibit an association between impaired graft function and higher Tacrolimus dosing. On the other hand, the minority of patients determined most sensitive to varying Tacrolimus levels showed a strong tendency to prefer low Tacrolimus dosing.

  6. Functional MRI of Delayed Chronic Lithium Treatment in Rat Focal Cerebral Ischemia

    PubMed Central

    Kim, Young R.; van Meer, Maurits P.A.; Tejima, Emiri; Murata, Yoshi; Mandeville, Joseph B.; Dai, George; Chuang, De-Maw; Rosen, Bruce R.; Lo, Eng H.

    2013-01-01

    Background and Purpose The use of lithium as a neuroprotective agent has been demonstrated using various models in which improvements in infarct size, DNA damage, and neurological function were reported. We further investigated neurohemodynamic aspects of the treatment-associated recovery by assessing the therapeutic efficacy of delayed chronic lithium treatment using functional MRI. Methods Ipsilesional functional MRI activations in the somatosensory cortex, acquired 2 weeks after the 90-minute transient middle cerebral artery occlusion, were compared between lithium- and saline-treated rats. Specifically, MRI signal changes based on blood oxygenation level dependence and functional cerebral blood volume responses were examined using electrical stimulation of forelimbs. Additional immunohistochemical assays were performed. Results The ratio of ipsilesional to contralesional blood oxygenation level dependence response magnitudes significantly improved with lithium treatments. In contrast, the increase of the functional cerebral blood volume response magnitude ratio was not statistically significant. Nonetheless, the lithium treatment induced significant enhancements of total functional MRI activation (defined as a product of activation volume and response magnitude) for both blood oxygenation level dependence and functional cerebral blood volume methods. Increased cerebral blood volume in periinfarct tissues suggests a possible stroke-induced vascular transformation in both saline- and lithium-treated rats; however, other MRI-derived vascular parameters (vascular size index and microvascular volume) and immunohistochemical staining (CD31, glia fibrillary-associated protein, and matrix metalloproteinase-9) may imply that the neoformation of vasculature was differently affected by the lithium treatment. Conclusions The delayed chronic lithium treatment enhanced the blood oxygenation level dependence functional MRI response magnitude in the absence of neurological

  7. Time-Delayed Mutual Information of the Phase as a Measure of Functional Connectivity

    PubMed Central

    Wilmer, Andreas; de Lussanet, Marc; Lappe, Markus

    2012-01-01

    We propose a time-delayed mutual information of the phase for detecting nonlinear synchronization in electrophysiological data such as MEG. Palus already introduced the mutual information as a measure of synchronization [1]. To obtain estimates on small data-sets as reliably as possible, we adopt the numerical implementation as proposed by Kraskov and colleagues [2]. An embedding with a parametric time-delay allows a reconstruction of arbitrary nonstationary connective structures – so-called connectivity patterns – in a wide class of systems such as coupled oscillatory or even purely stochastic driven processes [3]. By using this method we do not need to make any assumptions about coupling directions, delay times, temporal dynamics, nonlinearities or underlying mechanisms. For verifying and refining the methods we generate synthetic data-sets by a mutual amplitude coupled network of Rössler oscillators with an a-priori known connective structure. This network is modified in such a way, that the power-spectrum forms a power law, which is also observed in electrophysiological recordings. The functional connectivity measure is tested on robustness to additive uncorrelated noise and in discrimination of linear mixed input data. For the latter issue a suitable de-correlation technique is applied. Furthermore, the compatibility to inverse methods for a source reconstruction in MEG such as beamforming techniques is controlled by dedicated dipole simulations. Finally, the method is applied on an experimental MEG recording. PMID:23028571

  8. Endomorphins delay constitutive apoptosis and alter the innate host defense functions of neutrophils.

    PubMed

    Azuma, Yasutaka; Ohura, Kiyoshi; Wang, Pao-Li; Shinohara, Mitsuko

    2002-04-01

    Recent studies have shown that opioid peptides are released from cells of the immune system during inflammation and stress, and are associated with altered immune responses. Moreover, concentrations of opioid peptides are increased in peripheral blood and at the sites of inflammatory reactions. The aim of this study was to evaluate immunological effects of opioid peptides endomorphins 1 and 2 on constitutive apoptosis, superoxide anion production, hydrogen peroxide production, adhesion, phagocytosis, and chemotaxis of neutrophils. Neutrophils were isolated by peritoneal lavage from rats. Endomorphins 1 and 2 significantly delayed constitutive neutrophil apoptosis. The delay of neutrophil apoptosis was markedly attenuated by LY294002, a phosphoinositide 3-kinase inhibitor. Moreover, endomorphins 1 and 2 activated the phosphoinositide 3-kinase pathway as determined by phosphorylation of BAD. In contrast, endomorphins 1 and 2 blocked the production of superoxide anion and hydrogen peroxide by PMA-stimulated neutrophils. In addition, endomorphins 1 and 2 inhibited neutrophil adhesion to fibronectin. Moreover, endomorphins 1 and 2 potentiated neutrophil chemotaxis toward zymosan-activated serum and IL-8, respectively. However, endomorphins 1 and 2 did not alter phagocytosis of Escherichia coli by neutrophils. These results suggest that endomorphins 1 and 2 may act to delay neutrophil apoptosis and alter the natural immune functions of neutrophils.

  9. [Cognitive functions in elderly high-risk patients after off-pump coronary artery bypass grafting versus conventional bypass grafting - a randomised study - Secondary publication].

    PubMed

    Jensen, Birte Østergaard; Hughest, Pia; Rasmussen, Lars S; Pedersen, Preben U; Steinbrüchel, Daniel A

    2006-10-30

    It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting (OPCAB) than with conventional coronary artery bypass grafting (CCAB). The study is a part of the Best Bypass Surgery Trial. A total of 120 elderly patients underwent psychometric testing with a neuropsychological test battery before as well as 3 months after surgery. Cognitive dysfunction was identified in 7.4% of the patients in the OPCAB group and 9.8% in the CCAB group. We found no significant difference after either OPCAB or CCAB.

  10. Design of wide-area time-delay supplementary controller for interconnected Network based on Hamilton function method

    NASA Astrophysics Data System (ADS)

    Hailati, G.; Hu, Z. H.

    2016-08-01

    The transient stability of interconnected network with supplementary time-delay controller for generator excitations and static var compensator (SVC) has been investigated in this paper. Firstly, a delay-dependent stability criterion based on Hamilton function method is derived, and the criterion is in term of matrix inequalities. Secondly, a nonlinear time-delay Hamilton function model of interconnected network with SVCs is constructed. Thirdly, the wide-area time-delay supplementary controller (WATSC) for the interconnected network is designed and converted into the form of Hamiltonian system. The delay-dependent stability of the closed-loop power system is analysed. The gains of the WATSC are determined by using the theoretical analysis results. It is effective for the designed WATSC installed in the 16- machine, 68-bus power system for damping the inter-area modes. Then simulation results show that the method of the controller is effective.

  11. The rate, luminosity function and time delay of non-Collapsar short GRBs

    NASA Astrophysics Data System (ADS)

    Wanderman, David; Piran, Tsvi

    2015-04-01

    We estimate the rate and the luminosity function of short (hard) Gamma-Ray Bursts (sGRBs) that are non-Collapsars, using the peak fluxes and redshifts of BATSE, Swift and Fermi GRBs. Following Bromberg et al., we select a sub-sample of Swift bursts which are most likely non-Collapsars. We find that these sGRBs are delayed relative to the global star formation rate (SFR) with a typical delay time of a 3-4 Gyr (depending on the SFR model). However, if two or three sGRB at high redshifts have been missed because of selection effects, a distribution of delay times of ∝ 1/t would be also compatible. The current event rate of these non-Collapsar sGRBs with Liso > 5 × 1049 erg s-1 is 4.1_{-1.9}^{+2.3} Gpc^{-3} yr^{-1}. The rate was significantly larger around z ˜ 1 and it declines since that time. The luminosity function we find is a broken power law with a break at 2.0_{-0.4}^{+1.4} × 10^{52} erg s^{-1} and power-law indices 0.95_{-0.1 2}^{+0.12} and 2.0_{-0.8}^{+1.0}. When considering the whole Swift sGRB sample we find that it is composed of two populations: one group (≈60-80 per cent of Swift sGRBs) with the above rate and time delay and a second group (≈20-40 per cent of Swift sGRBs) of potential `impostors' that follow the SFR with no delay. These two populations are in very good agreement with the division of sGRBs to non-Collapsars and Collapsars suggested recently by Bromberg et al. If non-Collapsar sGRBs arise from neutron star merger this rate suggest a detection rate of 3-100 yr-1 by a future gravitational wave detectors (e.g. Advanced Ligo/Virgo with detection horizon on 300 Mpc), and a co-detection with Fermi (Swift ) rate of 0.1-1 yr-1 (0.02-0.14 yr-1). We estimate that about 4 × 10^5 (f_b^{-1}/30) mergers took place in the Milky Way. If 0.025M⊙ were ejected in each event this would have been sufficient to produce all the heavy r-process material in the Galaxy.

  12. Update on the slow delayed rectifier potassium current (I(Ks)): role in modulating cardiac function.

    PubMed

    Liu, Zhenzhen; Du, Lupei; Li, Minyong

    2012-01-01

    The slow delayed rectifier current (I(Ks)) is the slow component of cardiac delayed rectifier current and is critical for the late phase repolarization of cardiac action potential. This current is also an important target for Sympathetic Nervous System (SNS) to regulate the cardiac electivity to accommodate to heart rate alterations in response to exercise or emotional stress and can be up-regulated by β- adrenergic or other signal molecules. I(Ks) channel is originated by the co-assembly of pore-forming KCNQ1 α-subunit and accessory KCNE1 β-subunit. Mutations in any subunit can bring about severe long QT syndrome (LQT-1, LQT-5) as characterized by deliquium, seizures and sudden death. This review summarizes the normal physiological functions and molecular basis of I(Ks) channels, as well as illustrates up-to-date development on its blockers and activators. Therefore, the current extensive survey should generate fundamental understanding of the role of I(Ks) channel in modulating cardiac function and donate some instructions to the progression of I(Ks) blockers and activators as potential antiarrhythmic agents or pharmacological tools to determine the physiological and pathological function of I(Ks).

  13. Lipase-catalyzed synthesis of azido-functionalized aliphatic polyesters towards acid-degradable amphiphilic graft copolymers.

    PubMed

    Wu, Wan-Xia; Wang, Na; Liu, Bei-Yu; Deng, Qing-Feng; Yu, Xiao-Qi

    2014-02-28

    A series of novel aliphatic polyesters with azido functional groups were synthesized via the direct lipase-catalyzed polycondensation of dialkyl diester, diol and 2-azido-1,3-propanediol (azido glycerol) using immobilized lipase B from Candida antarctica (CALB). The effects of polymerization conditions including reaction time, temperature, enzyme amount, substrates and monomer feed ratio on the molecular weights of the products were studied. The polyesters with pendant azido groups were characterized by (1)H NMR, (13)C NMR, 2D NMR, FTIR, GPC and DSC. Alkyne end-functionalized poly(ethylene glycol) containing a cleavable acetal group was then grafted onto the polyester backbone by copper-catalyzed azide-alkyne cycloaddition (CuAAC, click chemistry). Using fluorescence spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM), these amphiphilic graft copolymers were found to readily self-assemble into nanosized micelles in aqueous solution with critical micelle concentrations between 0.70 and 1.97 mg L(-1), and micelle sizes from 20-70 nm. The degradation of these polymers under acidic conditions was investigated by GPC and (1)H NMR spectroscopy. Cell cytotoxicity tests indicated that the micelles had no apparent cytotoxicity to Bel-7402 cells, suggesting their potential as carriers for controlled drug delivery.

  14. Ligand-functionalized degradable polyplexes formed by cationic poly(aspartic acid)-grafted chitosan-cyclodextrin conjugates.

    PubMed

    Song, Hai-Qing; Li, Rui-Quan; Duan, Shun; Yu, Bingran; Zhao, Hong; Chen, Da-Fu; Xu, Fu-Jian

    2015-03-19

    Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE-FA/pDNA, and ternary CCPE-FA/CCPE/pDNA (prepared by layer-by-layer assembly) polyplexes were investigated in detail using different cell lines. The CCPE-based polyplexes displayed much higher transfection efficiencies than the CS-based polyplexes reported earlier by us. The ternary polyplexes of CCPE-FA/CCPE/pDNA produced excellent gene transfection abilities in the folate receptor (FR)-positive tumor cells. This work would provide a promising means to produce highly efficient polyplexes for future gene therapy applications.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. Early post-transplant urinary IP-10 expression after kidney transplantation is predictive of short- and long-term graft function.

    PubMed

    Matz, M; Beyer, J; Wunsch, D; Mashreghi, M-F; Seiler, M; Pratschke, J; Babel, N; Volk, H-D; Reinke, P; Kotsch, K

    2006-05-01

    The early identification of renal transplant recipients at enhanced risk of developing acute and subclinical rejection would allow individualized adjustment of immunosuppression before functional graft injury occurs and would exclude these patients from drug-weaning studies. Protein and reverse transcriptase-polymerase chain reaction-based analyses of candidate markers in urine open the opportunity to closely monitor kidney-transplanted patients non-invasively. The chemokine interferon-inducible protein 10 (IP-10; CXCL10) might be an interesting candidate to uncover ongoing immune processes within the graft. Urine samples from kidney-transplanted recipients were retrospectively analyzed for IP-10 mRNA and protein expression. IP-10 levels were correlated with the incidence of acute rejection episodes proven by histology and long-term graft function assessed by the glomerular filtration rate 6 months post transplantation. IP-10 expression in urine identified patients with ongoing acute rejection episodes several days before a biopsy was indicated by rising serum creatinine levels. Most importantly, elevated levels of urinary IP-10 protein within the first four postoperative weeks were predictive of graft function at 6 months even in the absence of acute rejection. These data reveal a correlation between elevated IP-10 expression in urine at early time points post-transplantation and intragraft immune activation that leads to acute rejection and compromised long-term graft function.

  17. Grafts in "closed" rhinoplasty.

    PubMed

    Scattolin, A; D'Ascanio, L

    2013-06-01

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

  18. PIGEONS' DELAY DISCOUNTING FUNCTIONS ESTABLISHED USING A CONCURRENT-CHAINS PROCEDURE

    PubMed Central

    Oliveira, Luís; Green, Leonard; Myerson, Joel

    2014-01-01

    Several studies have examined discounting by pigeons and rats using concurrent-chains procedures, but the results have been inconsistent. None of these studies, however, has established that discounting functions derived from estimates of indifference points can be obtained with a concurrent-chains procedure, so their validity remains in doubt. The present study used a concurrent-chains procedure within sessions combined with an adjusting-amount procedure across sessions to determine the present, subjective values of food reinforcers to be obtained after a delay. Discounting was well described by the hyperbolic discounting function, suggesting that the concurrent-chains procedure and the more typical adjusting-amount procedure are measuring the same process. Consistent with previous studies with rats and pigeons using adjusting-amount procedures, no significant effect of the amount of the delayed reinforcer on the degree of discounting was observed, suggesting that the amount effect may be unique to humans although consistent with the view that animals' choices are controlled by the relative, rather than the absolute, value of reinforcers. PMID:25044322

  19. Statistics of time delay and scattering correlation functions in chaotic systems. II. Semiclassical approximation

    SciTech Connect

    Novaes, Marcel

    2015-06-15

    We consider S-matrix correlation functions for a chaotic cavity having M open channels, in the absence of time-reversal invariance. Relying on a semiclassical approximation, we compute the average over E of the quantities Tr[S{sup †}(E − ϵ) S(E + ϵ)]{sup n}, for general positive integer n. Our result is an infinite series in ϵ, whose coefficients are rational functions of M. From this, we extract moments of the time delay matrix Q = − iħS{sup †}dS/dE and check that the first 8 of them agree with the random matrix theory prediction from our previous paper [M. Novaes, J. Math. Phys. 56, 062110 (2015)].

  20. Surface modification of aramid fibers by bio-inspired poly(dopamine) and epoxy functionalized silane grafting.

    PubMed

    Sa, Rina; Yan, Yan; Wei, Zhenhai; Zhang, Liqun; Wang, Wencai; Tian, Ming

    2014-12-10

    A novel biomimetic surface modification method for meta-aramid (MPIA) fibers and the improvement on adhesion with rubber matrix was demonstrated. Inspired by the composition of adhesive proteins in mussels, we used dopamine (DOPA) self-polymerization to form thin, surface-adherent poly(dopamine) (PDA) films onto the surface of MPIA fibers simply by immersing MPIA fibers in a dopamine solution at room temperature. An epoxy functionalized silane (KH560) grafting was then carried out on the surface of the poly(dopamine)-coated MPIA, either by a "one-step" or "two-step" method, to introduce an epoxy group onto the MPIA fiber surface. The surface composition and microstructure of the modified MPIA was characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results indicated successful grafting of KH560 on the PDA-coated MPIA surface. A single-fiber pull-out test was applied to evaluate the adhesion of MPIA fibers with the rubber matrix. Compared with the untreated MPIA fibers, the adhesion strength between the modified MPIA fibers by "one step" method with rubber matrix has an increase of 62.5%.

  1. Functional characterization of the apple MhGAI1 gene through ectopic expression and grafting experiments in tomatoes.

    PubMed

    Wang, Shuang-Shuang; Liu, Ze-Zhou; Sun, Chao; Shi, Qing-Hua; Yao, Yu-Xin; You, Chun-Xiang; Hao, Yu-Jin

    2012-02-15

    DELLA proteins are essential components of GA signal transduction. MhGAI1 was isolated from the tea crabapple (Malus hupehensis Redh. var. pingyiensis), and it was found to encode a DELLA protein. Mhgai1 is a GA-insensitive allele that was artificially generated via a bridge-PCR approach. Ectopic expression of Mhgai1 reduced plant stature, decreased spontaneous fruit-set-ratio and enhanced drought-tolerance in transgenic tomatoes. In addition, we examined the long-distance movement of Mhgai1 mRNAs by grafting experiments and SqRT-PCR analysis. It was found that the wild-type scions accumulated Mhgai1 transcripts trafficked from the transgenic rootstocks and therefore exhibited dwarf phenotypes. Furthermore, transgenic tomato plants produced more soluble solids, sugars and organic acids compared to wild-type tomatoes, suggesting an involvement of GA signaling in the regulation of fruit quality. Despite noticeable accumulation in the leaves and stems of WT scions, Mhgai1 transcripts were undetectable in flowers and fruit. Therefore, fruit quality was less influenced by the grafting of WT scions onto transgenic rootstocks than they were by the ectopic expression of Mhgai1 in transgenic rootstocks. Taken together, MhGAI1, which functions as a repressor in the GA signaling pathway, and its GA-insensitive allele, Mhgai1, could turn out to be useful targets for the genetic improvement of dwarfing rootstocks in apples.

  2. [Delayed puberty].

    PubMed

    Edouard, T; Tauber, M

    2010-02-01

    Delayed puberty is defined in girls by the absence of breast development beyond 13 years old and in boys by the absence of testicular enlargement (< 4 ml) beyond 14 years old. Simple investigations lead to the diagnosis of central or peripheral hypogonadism and constitutional delay of puberty. In girls, delayed puberty is rare and often organic, and then Turner syndrome should be systematically suspected. In boys, delayed puberty is often constitutional and functional. Treatment is etiologic when possible, hormonal replacement therapy (oestrogen in girls and testosterone in boys) and psychological management.

  3. The frenectomy combined with a laterally positioned pedicle graft. Functional and esthetic considerations.

    PubMed

    Miller, P D

    1985-02-01

    In many cases it is necessary to perform a frenectomy to prevent reopening of a midline diastema following closure by orthodontic therapy. Often the loss of the interdental papilla between the maxillary incisors during the classic frenectomy creates an unacceptable esthetic result. A surgical technique combining a frenectomy with a laterally positioned pedicle graft is presented. The interdental papilla is left surgically undisturbed if it is of physiologic size. If it is enlarged, gingivoplasty is performed to reduce it to an appropriate size. Closure across the midline by laterally positioning gingiva and healing by primary intention results in attached gingiva across the midline. This attached gingiva may have a bracing effect and thus aid in preventing orthodontic relapse (reopening of the diastema). Twenty-seven cases were treated. No relapse was found in 24 cases and in 3 cases only minimal relapse was noted (less than 1 mm). The esthetic result is superior to that obtained with the classic frenectomy technique.

  4. Octacalcium phosphate ceramics combined with gingiva-derived stromal cells for engineered functional bone grafts.

    PubMed

    Zorin, Vadim L; Komlev, Vladimir S; Zorina, Alla I; Khromova, Natalia V; Solovieva, Elena V; Fedotov, Alexander Yu; Eremin, Ilya I; Kopnin, Pavel B

    2014-08-28

    Biocompatible ceramic fillers are capable of sustaining bone formation in the proper environment. The major drawback of these scaffolding materials is the absence of osteoinductivity. To overcome this limitation, bioengineered scaffolds combine osteoconductive components (biomaterials) with osteogenic features such as cells and growth factors. The bone marrow mesenchymal stromal cells (BMMSCs) and the β-tricalcium phosphate (β-TCP) are well-known and characterized in this regard. The present study was conducted to compare the properties of novel octacalcium phosphate ceramic (OCP) granules with β-TCP (Cerasorb(®)), gingiva-derived mesenchymal stromal cells (GMSCs) properties with the BMMSCs and osteogenic and angiogenic properties of a bioengineered composite based on OCP granules and the GMSCs. This study demonstrates that GMSCs and BMMSСs have a similar osteogenic capacity. The usage of OCP ceramic granules in combination with BMMSCs/GMSCs significantly affects the osteo- and angiogenesis in bone grafts of ectopic models.

  5. Communication via gap junctions underlies early functional and beneficial interactions between grafted neural stem cells and the host.

    PubMed

    Jäderstad, Johan; Jäderstad, Linda M; Li, Jianxue; Chintawar, Satyan; Salto, Carmen; Pandolfo, Massimo; Ourednik, Vaclav; Teng, Yang D; Sidman, Richard L; Arenas, Ernest; Snyder, Evan Y; Herlenius, Eric

    2010-03-16

    How grafted neural stem cells (NSCs) and their progeny integrate into recipient brain tissue and functionally interact with host cells is as yet unanswered. We report that, in organotypic slice cultures analyzed by ratiometric time-lapse calcium imaging, current-clamp recordings, and dye-coupling methods, an early and essential way in which grafted murine or human NSCs integrate functionally into host neural circuitry and affect host cells is via gap-junctional coupling, even before electrophysiologically mature neuronal differentiation. The gap junctions, which are established rapidly, permit exogenous NSCs to influence directly host network activity, including synchronized calcium transients with host cells in fluctuating networks. The exogenous NSCs also protect host neurons from death and reduce such signs of secondary injury as reactive astrogliosis. To determine whether gap junctions between NSCs and host cells may also mediate neuroprotection in vivo, we examined NSC transplantation in two murine models characterized by degeneration of the same cell type (Purkinje neurons) from different etiologies, namely, the nervous and SCA1 mutants. In both, gap junctions (containing connexin 43) formed between NSCs and host cells at risk, and were associated with rescue of neurons and behavior (when implantation was performed before overt neuron loss). Both in vitro and in vivo beneficial NSC effects were abrogated when gap junction formation or function was suppressed by pharmacologic and/or RNA-inhibition strategies, supporting the pivotal mediation by gap-junctional coupling of some modulatory, homeostatic, and protective actions on host systems as well as establishing a template for the subsequent development of electrochemical synaptic intercellular communication.

  6. Communication via gap junctions underlies early functional and beneficial interactions between grafted neural stem cells and the host

    PubMed Central

    Jäderstad, Johan; Jäderstad, Linda M.; Li, Jianxue; Chintawar, Satyan; Salto, Carmen; Pandolfo, Massimo; Ourednik, Vaclav; Teng, Yang D.; Sidman, Richard L.; Arenas, Ernest; Snyder, Evan Y.; Herlenius, Eric

    2010-01-01

    How grafted neural stem cells (NSCs) and their progeny integrate into recipient brain tissue and functionally interact with host cells is as yet unanswered. We report that, in organotypic slice cultures analyzed by ratiometric time-lapse calcium imaging, current-clamp recordings, and dye-coupling methods, an early and essential way in which grafted murine or human NSCs integrate functionally into host neural circuitry and affect host cells is via gap-junctional coupling, even before electrophysiologically mature neuronal differentiation. The gap junctions, which are established rapidly, permit exogenous NSCs to influence directly host network activity, including synchronized calcium transients with host cells in fluctuating networks. The exogenous NSCs also protect host neurons from death and reduce such signs of secondary injury as reactive astrogliosis. To determine whether gap junctions between NSCs and host cells may also mediate neuroprotection in vivo, we examined NSC transplantation in two murine models characterized by degeneration of the same cell type (Purkinje neurons) from different etiologies, namely, the nervous and SCA1 mutants. In both, gap junctions (containing connexin 43) formed between NSCs and host cells at risk, and were associated with rescue of neurons and behavior (when implantation was performed before overt neuron loss). Both in vitro and in vivo beneficial NSC effects were abrogated when gap junction formation or function was suppressed by pharmacologic and/or RNA-inhibition strategies, supporting the pivotal mediation by gap-junctional coupling of some modulatory, homeostatic, and protective actions on host systems as well as establishing a template for the subsequent development of electrochemical synaptic intercellular communication. PMID:20147621

  7. Stochastic functional differential equations with infinite delay: Existence and uniqueness of solutions, solution maps, Markov properties, and ergodicity

    NASA Astrophysics Data System (ADS)

    Wu, Fuke; Yin, George; Mei, Hongwei

    2017-02-01

    This work is devoted to stochastic functional differential equations (SFDEs) with infinite delay. First, existence and uniqueness of the solutions of such equations are examined. Because the solutions of the delay equations are not Markov, a viable alternative for studying further asymptotic properties is to use solution maps or segment processes. By examining solution maps, this work investigates the Markov properties as well as the strong Markov properties. Also obtained are adaptivity and continuity, mean-square boundedness, and convergence of solution maps from different initial data. This paper then examines the ergodicity of underlying processes and establishes existence of the invariant measure for SFDEs with infinite delay under suitable conditions.

  8. Characterization and functional consequences of delayed rectifier current transient in ventricular repolarization.

    PubMed

    Gintant, G A

    2000-03-01

    Although inactivation of the rapidly activating delayed rectifier current (I(Kr)) limits outward current on depolarization, the role of I(Kr) (and recovery from inactivation) during repolarization is uncertain. To characterize I(Kr) during ventricular repolarization (and compare with the inward rectifier current, I(K1)), voltage-clamp waveforms simulating the action potential were applied to canine ventricular, atrial, and Purkinje myocytes. In ventricular myocytes, I(Kr) was minimal at plateau potentials but transiently increased during repolarizing ramps. The I(Kr) transient was unaffected by repolarization rate and maximal after 150-ms depolarizations (+25 mV). Action potential clamps revealed the I(Kr) transient terminating the plateau. Although peak I(Kr) transient density was relatively uniform among myocytes, potentials characterizing the peak transients were widely dispersed. In contrast, peak inward rectifier current (I(K1)) density during repolarization was dispersed, whereas potentials characterizing I(K1) defined a narrower (more negative) voltage range. In summary, rapidly activating I(Kr) provides a delayed voltage-dependent (and functionally time-independent) outward transient during ventricular repolarization, consistent with rapid recovery from inactivation. The heterogeneous voltage dependence of I(Kr) provides a novel means for modulating the contribution of this current during repolarization.

  9. Δ9-Tetrahydrocannabinol attenuates allogeneic host-versus-graft response and delays skin graft rejection through activation of cannabinoid receptor 1 and induction of myeloid-derived suppressor cells

    PubMed Central

    Sido, Jessica M.; Nagarkatti, Prakash S.; Nagarkatti, Mitzi

    2015-01-01

    Immune cells have been shown to express cannabinoid receptors and to produce endogenous ligands. Moreover, activation of cannabinoid receptors on immune cells has been shown to trigger potent immunosuppression. Despite such studies, the role of cannabinoids in transplantation, specifically to prevent allograft rejection, has not, to our knowledge, been investigated previously. In the current study, we tested the effect of THC on the suppression of HvGD as well as rejection of skin allografts. To this end, we studied HvGD by injecting H-2k splenocytes into H-2b mice and analyzing the immune response in the draining ingLNs. THC treatment significantly reduced T cell proliferation and activation in draining LNs of the recipient mice and decreased early stage rejection-indicator cytokines, including IL-2 and IFN-γ. THC treatment also increased the allogeneic skin graft survival. THC treatment in HvGD mice led to induction of MDSCs. Using MDSC depletion studies as well as adoptive transfer experiments, we found that THC-induced MDSCs were necessary for attenuation of HvGD. Additionally, using pharmacological inhibitors of CB1 and CB2 receptors and CB1 and CB2 knockout mice, we found that THC was working preferentially through CB1. Together, our research shows, for the first time to our knowledge, that targeting cannabinoid receptors may provide a novel treatment modality to attenuate HvGD and prevent allograft rejection. PMID:26034207

  10. Δ⁹-Tetrahydrocannabinol attenuates allogeneic host-versus-graft response and delays skin graft rejection through activation of cannabinoid receptor 1 and induction of myeloid-derived suppressor cells.

    PubMed

    Sido, Jessica M; Nagarkatti, Prakash S; Nagarkatti, Mitzi

    2015-09-01

    Immune cells have been shown to express cannabinoid receptors and to produce endogenous ligands. Moreover, activation of cannabinoid receptors on immune cells has been shown to trigger potent immunosuppression. Despite such studies, the role of cannabinoids in transplantation, specifically to prevent allograft rejection, has not, to our knowledge, been investigated previously. In the current study, we tested the effect of THC on the suppression of HvGD as well as rejection of skin allografts. To this end, we studied HvGD by injecting H-2(k) splenocytes into H-2(b) mice and analyzing the immune response in the draining ingLNs. THC treatment significantly reduced T cell proliferation and activation in draining LNs of the recipient mice and decreased early stage rejection-indicator cytokines, including IL-2 and IFN-γ. THC treatment also increased the allogeneic skin graft survival. THC treatment in HvGD mice led to induction of MDSCs. Using MDSC depletion studies as well as adoptive transfer experiments, we found that THC-induced MDSCs were necessary for attenuation of HvGD. Additionally, using pharmacological inhibitors of CB1 and CB2 receptors and CB1 and CB2 knockout mice, we found that THC was working preferentially through CB1. Together, our research shows, for the first time to our knowledge, that targeting cannabinoid receptors may provide a novel treatment modality to attenuate HvGD and prevent allograft rejection.

  11. Synthesis of an end-group functionalized polyethylene glycol-lipid conjugate for preparation of polymer-grafted liposomes.

    PubMed

    Zalipsky, S

    1993-01-01

    Synthesis of a distearoylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG) conjugate, bearing a hydrazide group at the unattached end of the polymer chain, was achieved using a new heterobifunctional polymeric reagent. The heterobifunctional PEG derivative carrying on one end a reactive succinimidyl carbonate (SC) group and at the other terminal a tert-butyloxycarbonyl (Boc) protected hydrazide group was prepared by an efficient four step process from readily available PEG-2000. The SC-end group of the polymer reacted readily with the amino group of DSPE forming a stable urethane attachment between lipid and PEG. Acidolytic removal of the Boc group yielded a hydrazide-PEG-lipid conjugate suitable for preparation of polymer-grafted liposomes. Taking advantage of the well-documented chemical versatility of hydrazide groups, various biologically relevant ligands can be linked to this type of functionalized liposomes.

  12. Ligand-functionalized degradable polyplexes formed by cationic poly(aspartic acid)-grafted chitosan-cyclodextrin conjugates

    NASA Astrophysics Data System (ADS)

    Song, Hai-Qing; Li, Rui-Quan; Duan, Shun; Yu, Bingran; Zhao, Hong; Chen, Da-Fu; Xu, Fu-Jian

    2015-03-01

    Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE-FA/pDNA, and ternary CCPE-FA/CCPE/pDNA (prepared by layer-by-layer assembly) polyplexes were investigated in detail using different cell lines. The CCPE-based polyplexes displayed much higher transfection efficiencies than the CS-based polyplexes reported earlier by us. The ternary polyplexes of CCPE-FA/CCPE/pDNA produced excellent gene transfection abilities in the folate receptor (FR)-positive tumor cells. This work would provide a promising means to produce highly efficient polyplexes for future gene therapy applications.Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE

  13. Bone grafts.

    PubMed

    Hubble, Matthew J W

    2002-09-01

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

  14. Analytic Root Locus and Lambert W Function in Control of a Process with Time Delay

    NASA Astrophysics Data System (ADS)

    Cogan, Brian; de Paor, Annraoi M.

    2011-11-01

    Recently, the Lambert W function has arisen in the analysis of many systems including a restricted class of time-delay systems. An alternative approach to this analysis, based on the well-established root locus method, is shown here to contain the Lambert W function as a special case. As a purely illustrative example of the equivalence between the Lambert W function and analytic root locus a system comprising a Proportional controller with a time-delay process is analysed. Controller designs based on rightmost eigenvalue location and the dominant eigenvalue method are described.

  15. Dichoptic Metacontrast Masking Functions to Infer Transmission Delay in Optic Neuritis

    PubMed Central

    Bruchmann, Maximilian; Korsukewitz, Catharina; Krämer, Julia; Wiendl, Heinz; Meuth, Sven G.

    2016-01-01

    Optic neuritis (ON) has detrimental effects on the transmission of neuronal signals generated at the earliest stages of visual information processing. The amount, as well as the speed of transmitted visual signals is impaired. Measurements of visual evoked potentials (VEP) are often implemented in clinical routine. However, the specificity of VEPs is limited because multiple cortical areas are involved in the generation of P1 potentials, including feedback signals from higher cortical areas. Here, we show that dichoptic metacontrast masking can be used to estimate the temporal delay caused by ON. A group of 15 patients with unilateral ON, nine of which had sufficient visual acuity and volunteered to participate, and a group of healthy control subjects (N = 8) were presented with flashes of gray disks to one eye and flashes of gray annuli to the corresponding retinal location of the other eye. By asking subjects to report the subjective visibility of the target (i.e. the disk) while varying the stimulus onset asynchrony (SOA) between disk and annulus, we obtained typical U-shaped masking functions. From these functions we inferred the critical SOAmax at which the mask (i.e. the annulus) optimally suppressed the visibility of the target. ON-associated transmission delay was estimated by comparing the SOAmax between conditions in which the disk had been presented to the affected and the mask to the other eye, and vice versa. SOAmax differed on average by 28 ms, suggesting a reduction in transmission speed in the affected eye. Compared to previously reported methods assessing perceptual consequences of altered neuronal transmission speed the presented method is more accurate as it is not limited by the observers’ ability to judge subtle variations in perceived synchrony. PMID:27711139

  16. Teaching a Child with Autism and Severe Language Delays to Reject: Direct and Indirect Effects of Functional Communication Training

    ERIC Educational Resources Information Center

    Martin, Christian A.; Drasgow, Erik; Halle, James W.; Brucker, Jennifer M.

    2005-01-01

    We used functional communication training to teach Bob, a 10-year-old student with autism and severe language delays, to reject items by touching an icon. Our initial assessment revealed that Bob's behaviours serving a rejecting function consisted of pushing away, yelling, bear hugging-grabbing, and leaving. We used prompting, differential…

  17. Graft-versus-host reaction and immune function. III. Functional pre-T cells in the bone marrow of graft-versus-host-reactive mice displaying T cell immunodeficiency

    SciTech Connect

    Seddik, M.; Seemayer, T.A.; Lapp, W.S.

    1986-02-01

    Studies were performed to determine whether pre-T cells develop normally in the bone marrow of mice displaying thymic dysplasia and T cell immunodeficiency as a consequence of a graft-versus-host (GVH) reaction. GVH reactions were induced in CBAxAF1 mice by the injection of A strain lymphoid cells. To test for the presence of pre-T cells in GVH-reactive mice, bone marrow from GVH-reactive mice (GVHBM) was injected into irradiated syngeneic F1 mice and 30-40 days later thymic morphology and function were studied. Morphology studies showed nearly normal thymic architectural restoration; moreover, such glands contained normal numbers of Thy-1-positive cells. Functional pre-T cells were evaluated by transferring thymocytes from the irradiated GVHBM-reconstituted mice into T-cell-deprived mice. These thymocytes reconstituted allograft reactivity, T helper cell function and Con A and PHA mitogen responses of T-cell-deprived mice. These results suggest that the pre-T cell population in the bone marrow is not affected by the GVH reaction. Therefore, the T cell immunodeficiency associated with the GVH reaction is not due to a deficiency of pre-T cells in the bone marrow but is more likely associated with GVH-induced thymic dysplasia.

  18. An application of higher order connection to inverse function delayed network

    NASA Astrophysics Data System (ADS)

    Sota, Takahiro; Hayakawa, Yoshihiro; Sato, Shigeo; Nakajima, Koji

    The Inverse function Delayed model (ID model) is a neuron model with negative resistance dynamics. The negative resistance can destabilize local minimum states, which are undesirable network responses. The ID network can remove these states. Actually, we have demonstrated that the ID network can perfectly remove all local minima with N-Queen problems or 4-Color problems, where stationary stable states always give correct answers. However this method cannot apply to Traveling Salesman Problems (TSPs) or Quadratic Assignment Problems (QAPs). Meanwhile, it is proposed that the TSPs are able to be represented in terms of the quartic form energy function. In this representation, the global minimum states that represent correct answers and the local minimum states are separable clearly, thus if it is applied to the ID network, it ensures that only the local minimum states are destabilized by the negative resistance. In this paper, we aim to introduce higher order connections to the ID network to apply the quartic form energy function. We apply the ID network with higher order connections to the TSPs or QAPs, and show that the higher order connection ID network can destabilize only the local minimum states by the negative resistance effect, so that it obtains only correct answers found at stationary stable states. Moreover, we obtain minimum parameter region analytically to destabilize every local minimum state.

  19. Spatiotemporal Dynamics and Hopf Bifurcation in a Delayed Diffusive Intraguild Predation Model with Holling II Functional Response

    NASA Astrophysics Data System (ADS)

    Han, Renji; Dai, Binxiang

    We propose a kind of delayed diffusive intraguild predation model with Holling II functional response in this paper. By analyzing the eigenvalue spectrum, it is found that the stability or instability of equilibria can be induced by delay. By utilizing the local bifurcation theory of partial functional differential equations, Hopf bifurcation of the proposed system with time delay as bifurcation parameter is investigated. It reveals that the time delay has a destabilizing effect in the intraguild predation model dynamics and a phenomenon of Hopf bifurcation occurs when the delay increases through a certain threshold. Then we give the explicit formulas to determine the direction, stability of Hopf bifurcation by utilizing the normal form method and center manifold reduction for PFDEs. Numerical simulations are performed to illustrate our theoretical results and show that delay and diffusion can induce the system into chaos and even trigger the emergence of different types of spatial patterns, including spiral wave pattern and chaotic wave pattern, which are induced by Hopf instability.

  20. Delayed convergence between brain network structure and function in rolandic epilepsy

    PubMed Central

    Besseling, René M. H.; Jansen, Jacobus F. A.; Overvliet, Geke M.; van der Kruijs, Sylvie J. M.; Ebus, Saskia C. M.; de Louw, Anton J. A.; Hofman, Paul A. M.; Aldenkamp, Albert P.; Backes, Walter H.

    2014-01-01

    Introduction: Rolandic epilepsy (RE) manifests during a critical phase of brain development, and has been associated with language impairments. Concordant abnormalities in structural and functional connectivity (SC and FC) have been described before. As SC and FC are under mutual influence, the current study investigates abnormalities in the SC-FC synergy in RE. Methods: Twenty-two children with RE (age, mean ± SD: 11.3 ± 2.0 y) and 22 healthy controls (age 10.5 ± 1.6 y) underwent structural, diffusion weighted, and resting-state functional magnetic resonance imaging (MRI) at 3T. The probabilistic anatomical landmarks atlas was used to parcellate the (sub)cortical gray matter. Constrained spherical deconvolution tractography and correlation of time series were used to assess SC and FC, respectively. The SC-FC correlation was assessed as a function of age for the non-zero structural connections over a range of sparsity values (0.01–0.75). A modularity analysis was performed on the mean SC network of the controls to localize potential global effects to subnetworks. SC and FC were also assessed separately using graph analysis. Results: The SC-FC correlation was significantly reduced in children with RE compared to healthy controls, especially for the youngest participants. This effect was most pronounced in a left and a right centro-temporal network, as well as in a medial parietal network. Graph analysis revealed no prominent abnormalities in SC or FC network organization. Conclusion: Since SC and FC converge during normal maturation, our finding of reduced SC-FC correlation illustrates impaired synergy between brain structure and function. More specifically, since this effect was most pronounced in the youngest participants, RE may represent a developmental disorder of delayed brain network maturation. The observed effects seem especially attributable to medial parietal connections, which forms an intermediate between bilateral centro-temporal modules of

  1. Hemodynamic Functions of Fenestrated Stent Graft under Resting, Hypertension, and Exercise Conditions

    PubMed Central

    Kandail, Harkamaljot Singh; Hamady, Mohamad; Xu, Xiao Yun

    2016-01-01

    The aim of this study was to assess the hemodynamic performance of a patient-specific fenestrated stent graft (FSG) under different physiological conditions, including normal resting, hypertension, and hypertension with moderate lower limb exercise. A patient-specific FSG model was constructed from computed tomography images and was discretized into a fine unstructured mesh comprising tetrahedral and prism elements. Blood flow was simulated using Navier–Stokes equations, and physiologically realistic boundary conditions were utilized to yield clinically relevant results. For a given cycle-averaged inflow of 2.08 L/min at normal resting and hypertension conditions, approximately 25% of flow was channeled into each renal artery. When hypertension was combined with exercise, the cycle-averaged inflow increased to 6.39 L/min but only 6.29% of this was channeled into each renal artery, which led to a 438.46% increase in the iliac flow. For all the simulated scenarios and throughout the cardiac cycle, the instantaneous flow streamlines in the FSG were well organized without any notable flow recirculation. This well-organized flow led to low values of endothelial cell activation potential, which is a hemodynamic metric used to identify regions at risk of thrombosis. The displacement forces acting on the FSG varied with the physiological conditions, and the cycle-averaged displacement force at normal rest, hypertension, and hypertension with exercise was 6.46, 8.77, and 8.99 N, respectively. The numerical results from this study suggest that the analyzed FSG can maintain sufficient blood perfusion to the end organs at all the simulated conditions. Even though the FSG was found to have a low risk of thrombosis at rest and hypertension, this risk can be reduced even further with moderate lower limb exercise. PMID:27379242

  2. Anatomical and functional graft survival, 10 years after epikeratoplasty in keratoconus

    PubMed Central

    Panda, Anita; Gupta, Anoop K; Sharma, Namrata; Nindrakrishna, Sasikala; Vajpayee, Rasik

    2013-01-01

    Purpose: To report outcomes of epikeratoplasty in keratoconus (KC), utilizing manually-prepared plano donor lenticules in terms of flattening of the cone, reduction in astigmatism and improvement in the visual acuity. Materials and Methods: Patients with KC, having visual acuity <20/200, astigmatism >12 diopters (D) but without corneal opacity underwent epikeratoplasty, using manually prepared plano donor lenticules from fresh or M.K preserved corneas, between 1990 - 2000 and followed for 10 years, were included in this report. Visual acuity slit-lamp-biomicroscopy, keratometry, and refraction were performed at 8 weeks, 12 weeks, and 6 months for all 59 patients. The same were carried out at 1 year, 5 years, and 10 years depending upon the availability of the patient for that period. Results: Of the 59 patients, only 26 were available for follow-up after 10 years. At 3 months, 1 year and 5 years, best corrected visual acuity of (BCVA) ≥20/60 were achieved in 84.7%, 84.4% and 80.3% of eyes, respectively. BCVA was 73% at 10-year follow- up, which was due to the presence of posterior subcapsular cataract (PSC). The average keratometric astigmatism and average flattening in diopters stabilized at the end of 3 months, which remained constant at 1, 5, and 10-year follow-up. The average diopter of myopia was stabilized by 1 year, which was almost same at 10 year. Graft was clear in all but 1 eye at 10 year follow-up. Conclusion: Epikeratoplasty is a useful technique for keratoconic eyes without apical scarring who fail or unable to use contact lenses. PMID:23275216

  3. Acute effects of ginger extract on biochemical and functional symptoms of delayed onset muscle soreness

    PubMed Central

    Hoseinzadeh, Khadijeh; Daryanoosh, Farhad; Baghdasar, Parvin Javad; Alizadeh, Hamid

    2015-01-01

    Background: Inflammation and pain induced by delayed onset muscle soreness (DOMS) as a result of eccentric exercise (EE) or unaccustomed activity cause some difficulties in exercise for athletes. The purpose of this study was to survey the effect of ginger extract on biochemical and functional symptom of delayed onset muscle soreness. Methods: In a quasi-experimental study, 36 healthy female subjects, who were recruited by intra dormitory calls, randomly divided into 3 groups, including: ginger intake 1 hour before exercise (GIBE), ginger intake immediately after exercise (GIAE) and placebo group (PL). Subjects consumed capsules contain 60 mg of ginger extract (equivalent of 2 g dried ginger powder) or placebo before and after exercise. The exercise protocol consisted of a 20 minute step test using a 46cm step at a rate of 15 steps per minute. The blood samples were taken before, 1, 24 and 48 hour after exercise to assay creatine kinase (CK) and interleukin-6 (IL-6). Muscle pain scores, isometric strength and circumference of thigh muscle, and hip range of motion were recorded at mentioned times. The analysis of variance (ANOVA) with repeated measure was used to determine the differences between groups. Results: The results showed a significant reduction of pain in GIBE compared to GIAE after 24 and 48h of EE and GIAE compared to PL (p<0.05). IL-6 changed significantly in GIBE compared to PL (p<0.05) after 1, 24, and 48h after EE. The other factors didn’t change meaningfully. Conclusion: The finding of this study suggests that 2 grams of ginger may have anti-inflammation and analgesic effect on DOMS. PMID:26793652

  4. DIRECT MEASUREMENT OF THE X-RAY TIME-DELAY TRANSFER FUNCTION IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Legg, E.; Miller, L.; Turner, T. J.; Giustini, M.; Reeves, J. N.; Kraemer, S. B.

    2012-11-20

    The origin of the observed time lags, in nearby active galactic nuclei (AGNs), between hard and soft X-ray photons is investigated using new XMM-Newton data for the narrow-line Seyfert I galaxy Ark 564 and existing data for 1H 0707-495 and NGC 4051. These AGNs have highly variable X-ray light curves that contain frequent, high peaks of emission. The averaged light curve of the peaks is directly measured from the time series, and it is shown that (1) peaks occur at the same time, within the measurement uncertainties, at all X-ray energies, and (2) there exists a substantial tail of excess emission at hard X-ray energies, which is delayed with respect to the time of the main peak, and is particularly prominent in Ark 564. Observation (1) rules out that the observed lags are caused by Comptonization time delays and disfavors a simple model of propagating fluctuations on the accretion disk. Observation (2) is consistent with time lags caused by Compton-scattering reverberation from material a few thousand light-seconds from the primary X-ray source. The power spectral density and the frequency-dependent phase lags of the peak light curves are consistent with those of the full time series. There is evidence for non-stationarity in the Ark 564 time series in both the Fourier and peaks analyses. A sharp 'negative' lag (variations at hard photon energies lead soft photon energies) observed in Ark 564 appears to be generated by the shape of the hard-band transfer function and does not arise from soft-band reflection of X-rays. These results reinforce the evidence for the existence of X-ray reverberation in type I AGN, which requires that these AGNs are significantly affected by scattering from circumnuclear material a few tens or hundreds of gravitational radii in extent.

  5. Functional delay and sum beamforming for three-dimensional acoustic source identification with solid spherical arrays

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Chu, Zhigang; Shen, Linbang; Xu, Zhongming

    2016-07-01

    Solid spherical arrays have become particularly attractive tools for doing acoustic sources identification in cabin environments. Spherical harmonics beamforming (SHB) is the popular conventional algorithm. Regrettably, its results suffer from severe sidelobe contaminations and the existing solutions are incapable of removing these contaminations both significantly and efficiently. This paper focuses on conquering these problems by creating a novel functional delay and sum (FDAS) algorithm. First and foremost, a new delay and sum (DAS) algorithm is established, and for which, the point spread function (PSF) is derived, the determination principle of the truncated upper limit of the spherical harmonics degree is explored, and the performance is examined as well as compared with that of SHB. Next, the FDAS algorithm is created by combining DAS and the functional beamforming (FB) approach initially suggested for planar arrays, and its merits are demonstrated. Additionally, performances of DAS and FDAS are probed into under the situation that the source is not at the focus point. Several interesting results have emerged: (1) the truncated upper limit of the spherical harmonics degree, capable of making DAS meet FB's requirement, exists and its minimum value depends only on the wave number and the array radius. (2) DAS can accurately locate and quantify the single source and the incoherent or coherent sources, and its comprehensive performance is not inferior to that of SHB. (3) For single source or incoherent sources, FDAS can not only accurately locate and quantify the source, but also significantly and efficiently attenuate sidelobes, effectively detect weak sources and acquire somewhat better spatial resolution. In contrast to that, for coherent sources, FDAS is not available. (4) DAS can invariably quantify the source accurately, irrespectively of the focus distance, whereas FDAS is burdened with a quantification deviation growing with the increase of the exponent

  6. Effects of Massage on Delayed-Onset Muscle Soreness, Swelling, and Recovery of Muscle Function

    PubMed Central

    Zainuddin, Zainal; Newton, Mike; Sacco, Paul; Nosaka, Kazunori

    2005-01-01

    Context: Delayed-onset muscle soreness (DOMS) describes muscle pain and tenderness that typically develop several hours postexercise and consist of predominantly eccentric muscle actions, especially if the exercise is unfamiliar. Although DOMS is likely a symptom of eccentric-exercise–induced muscle damage, it does not necessarily reflect muscle damage. Some prophylactic or therapeutic modalities may be effective only for alleviating DOMS, whereas others may enhance recovery of muscle function without affecting DOMS. Objective: To test the hypothesis that massage applied after eccentric exercise would effectively alleviate DOMS without affecting muscle function. Design: We used an arm-to-arm comparison model with 2 independent variables (control and massage) and 6 dependent variables (maximal isometric and isokinetic voluntary strength, range of motion, upper arm circumference, plasma creatine kinase activity, and muscle soreness). A 2-way repeated-measures analysis of variance and paired t tests were used to examine differences in changes of the dependent variable over time (before, immediately and 30 minutes after exercise, and 1, 2, 3, 4, 7, 10, and 14 days postexercise) between control and massage conditions. Setting: University laboratory. Patients or Other Participants: Ten healthy subjects (5 men and 5 women) with no history of upper arm injury and no experience in resistance training. Intervention(s): Subjects performed 10 sets of 6 maximal isokinetic (90°·s−1) eccentric actions of the elbow flexors with each arm on a dynamometer, separated by 2 weeks. One arm received 10 minutes of massage 3 hours after eccentric exercise; the contralateral arm received no treatment. Main Outcome Measure(s): Maximal voluntary isometric and isokinetic elbow flexor strength, range of motion, upper arm circumference, plasma creatine kinase activity, and muscle soreness. Results: Delayed-onset muscle soreness was significantly less for the massage condition for peak

  7. The Effect of Osmotherapy and Tight Control of Acidosis on Early Graft Function among Deceased-Donor Kidney Transplant Recipients: A Randomized Controlled Trial

    PubMed Central

    Etezadi, F.; Najafi Abrandabadi, A. H.; Motaharinia, J.; Mojtahedzadeh, M.; Pourfakhr, P.; Khajavi, M. R.; Gooran, S.; Shariat Moharari, R.; Dehghani, S.

    2017-01-01

    Background: Reperfusion injury and the acid-base status of the transplant are important factors affecting post-transplantation graft function. Objective: We hypothesized that infusing hypertonic saline (HS) or tight control of acid-base status of the blood rushing through renal graft using sodium bicarbonate may have beneficial effects on early graft function. Methods: Candidates for deceased-donor kidney transplant were randomized into three groups. HS group (n=33) received 50 mL/kg normal saline (NS) titrated during operation plus 4 mL/kg of 5% HS just within graft reperfusion phase; bicarbonate group (n=37) was administered 60 mL/kg NS while their metabolic acidosis (base excess ≤5 mEq/L) was tightly corrected every 30 min with sodium bicarbonate; and a control group (n=36) that received 60 mL/kg normal saline while they were administered sodium bicarbonate only, if they encountered severe metabolic acidosis (base excess ≤15 mEq/L). The primary outcome was defined as early post-operative renal function evaluated based on serial serum creatinine levels. The study was registered in Iranian Registry of Clinical Trials (IRCT2013122815841N19). Results: Post-operative early graft function improved significantly during the first 3 days in the intervention groups (p<0.05). However, that beneficial effect no longer remained at the same level after the day four. Conclusion: Timely administration of HS or tight control of metabolic acidosis with sodium bicarbonate infusion improve early renal function during renal transplant surgery. PMID:28299023

  8. Surface functionalization of bioactive glasses with natural molecules of biological significance, part II: Grafting of polyphenols extracted from grape skin

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Ferraris, Sara; Prenesti, Enrico; Verné, Enrica

    2013-12-01

    Polyphenols, as one of the most important family of phytochemicals protective substances from grape fruit, possess various biological activities and health-promoting benefits, for example: inhibition of some degenerative diseases, cardiovascular diseases and certain types of cancers, reduction of plasma oxidative stress and slowing aging. The combination of polyphenols and biomaterials may have good potential to reach good bioavailability and controlled release, as well as to give biological signaling properties to the biomaterial surfaces. In this research, conventional solvent extraction was developed for obtaining polyphenols from dry grape skins. The Folin&Ciocalteu method was used to determine the amount of total polyphenols in the extracts. Surface functionalization of two bioactive glasses (SCNA and CEL2) was performed by grafting the extracted polyphenols on their surfaces. The effectiveness of the functionalization was tested by UV spectroscopy, which analyzes the amount of polyphenols in the uptake solution (before and after functionalization) and on solid samples, and XPS, which analyzes the presence of phenols on the material surface.

  9. Delayed Presentation of Ureteropelvic Junction Obstruction and Loss of Renal Function After Initially Mild (SFU Grade 1-2) Hydronephrosis.

    PubMed

    Bowen, Diana K; Yerkes, Elizabeth B; Lindgren, Bruce W; Gong, Edward M; Faasse, Mark A

    2015-07-01

    We report 4 pediatric cases of ureteropelvic junction obstruction involving delayed progression of initially mild postnatal hydronephrosis. All 4 children became symptomatic; however, 3 already had a substantial decrement of ipsilateral kidney function by the time of diagnosis. Two of these 3 patients had previous renal scintigraphy demonstrating normal differential function. We caution that counseling regarding hydronephrosis should emphasize the importance of prompt re-evaluation for any symptoms potentially referable to delayed presentation of ureteropelvic junction obstruction, irrespective of initial hydronephrosis grade. Future studies are needed to determine the optimal follow-up regimen for conservative management of hydronephrosis.

  10. Increasing MuSK activity delays denervation and improves motor function in ALS mice.

    PubMed

    Pérez-García, María J; Burden, Steven J

    2012-09-27

    Amyotrophic lateral sclerosis (ALS) is a devastating disease that progresses from detachment of motor nerve terminals to complete muscle paralysis and lethal respiratory failure within 5 years of diagnosis. Genetic studies have linked mutations in several genes to ALS, and mice bearing mutations in SOD1 recapitulate hallmark features of the disease. We investigated whether disease symptoms can be ameliorated by co-opting the retrograde signaling pathway that promotes attachment of nerve terminals to muscle. We crossed SOD1G93A mice with transgenic mice that express MuSK, a receptor tyrosine kinase that is required for retrograde signaling, and we used histological and behavioral assays to assess motor innervation and behavior. A 3-fold increase in MuSK expression delayed the onset and reduced the extent of muscle denervation, improving motor function for more than a month without altering survival. These findings suggest that increasing MuSK activity by pharmacological means has the potential to improve motor function in ALS.

  11. Design of the inverse function delayed neural network for solving combinatorial optimization problems.

    PubMed

    Hayakawa, Yoshihiro; Nakajima, Koji

    2010-02-01

    We have already proposed the inverse function delayed (ID) model as a novel neuron model. The ID model has a negative resistance similar to Bonhoeffer-van der Pol (BVP) model and the network has an energy function similar to Hopfield model. The neural network having an energy can converge on a solution of the combinatorial optimization problem and the computation is in parallel and hence fast. However, the existence of local minima is a serious problem. The negative resistance of the ID model can make the network state free from such local minima by selective destabilization. Hence, we expect that it has a potential to overcome the local minimum problems. In computer simulations, we have already shown that the ID network can be free from local minima and that it converges on the optimal solutions. However, the theoretical analysis has not been presented yet. In this paper, we redefine three types of constraints for the particular problems, then we analytically estimate the appropriate network parameters giving the global minimum states only. Moreover, we demonstrate the validity of estimated network parameters by computer simulations.

  12. Functional performance of school children diagnosed with developmental delay up to two years of age

    PubMed Central

    Dornelas, Lílian de Fátima; Magalhães, Lívia de Castro

    2016-01-01

    Abstract Objective: To compare the functional performance of students diagnosed with developmental delay (DD) up to two years of age with peers exhibiting typical development. Methods: Cross-sectional study with functional performance assessment of children diagnosed with DD up to two years of age compared to those with typical development at seven to eight years of age. Each group consisted of 45 children, selected by non-random sampling, evaluated for motor skills, quality of home environment, school participation and performance. ANOVA and the Binomial test for two proportions were used to assess differences between groups. Results: The group with DD had lower motor skills when compared to the typical group. While 66.7% of children in the typical group showed adequate school participation, receiving aid in cognitive and behavioral tasks similar to that offered to other children at the same level, only 22.2% of children with DD showed the same performance. Although 53.3% of the children with DD achieved an academic performance expected for the school level, there were limitations in some activities. Only two indicators of family environment, diversity and activities with parents at home, showed statistically significant difference between the groups, with advantage being shown for the typical group. Conclusions: Children with DD have persistent difficulties at school age, with motor deficit, restrictions in school activity performance and low participation in the school context, as well as significantly lower functional performance when compared to children without DD. A systematic monitoring of this population is recommended to identify needs and minimize future problems. PMID:26553573

  13. Photo-initiated grafting of gelatin/N-maleic acyl-chitosan to enhance endothelial cell adhesion, proliferation and function on PLA surface.

    PubMed

    Zhu, Aiping; Zhao, Feng; Ma, Teng

    2009-07-01

    Vascular graft surface properties significantly affect adhesion, growth and function of endothelial cells (ECs). The bulk degradation property of poly(lactic acid) (PLA) makes it possible for it to be replaced by cellular materials and PLA is desirable as a scaffold material for vascular grafts. However, PLA has an unfavorable surface property for EC adhesion and proliferation due to the lack of a selective cell adhesion motif. Photo-initiated surface-grafting polymerization is a promising method for immobilizing certain biomacromolecules on material surfaces without compromising bulk properties. N-Maleic acyl-chitosan (NMCS) is a novel biocompatible amphiphilic derivative of chitosan with double bonds and can be initiated by ultraviolet light. In this study, gelatin was complexed with NMCS via hydrophobic interaction, and gel/NMCS complex thus formed was then grafted on the PLA surface to improve EC biocompatibility. X-ray photoelectron and Fourier transform infrared spectroscopy, and water contact angle measurement confirmed immobilization of the gel/NMCS complex on PLA surface. Moreover, the gel/NMCS modified PLA enhanced human umbilical vein endothelial cell (HUVEC) spreading and flattening, and promoted the expression of more structured CD31 and vWF compared to unmodified PLA film. Compared to the unmodified PLA surface, the HUVECs on the modified PLA surface had elevated uptake of acetylated low-density lipoprotein, and maintained the ability to modulate metabolic activity upon exposure to shear stress at 5dyncm(-2) by up-regulating nitric oxide and prostacyclin production. Cell retention was 1.6 times higher on the gel/NMCS-PLA surface, demonstrating its improved potential for hemocompatibility. These results indicate that photo-initiated surface-grafting of the biomimetic gel/NMCS complex is an effective method to modify material surfaces as vascular grafts.

  14. Effect of cold storage on immediate graft function in an experimental model of renal transplantation in cats.

    PubMed

    Csomos, Rebecca A; Hardie, Robert J; Schmiedt, Chad W; Delaney, Fern A; McAnulty, Jonathan F

    2017-03-01

    OBJECTIVE To assess the effect of cold storage (CS) on immediate posttransplantation function of renal autografts in cats. ANIMALS 15 healthy 1-year-old cats. PROCEDURES Cats were assigned to 2 groups and underwent autotransplantation of the left kidney followed by nephrectomy of the right kidney. The left kidney was autotransplanted either immediately (IT group; n = 6) or after being flushed with a cold sucrose phosphate solution and stored on ice while the implant site was prepared (CS group; 9). Serum creatinine and BUN concentrations were monitored daily and autografts were ultrasonographically examined intermittently for 14 days after surgery. RESULTS Mean duration of CS was 24 minutes for the CS group. Posttransplantation serum creatinine and BUN concentrations for the CS group had lower peak values, returned to the respective reference ranges quicker, and were generally significantly lower than those for the IT group. Mean posttransplantation autograft size for the CS group was smaller than that for the IT group. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that immediate posttransplantation function of renal autografts following a short period of CS was better than that of renal autografts that did not undergo CS, which suggested CS protected grafts from ischemic injury and may decrease perioperative complications, speed recovery, and improve the long-term outcome for cats with renal transplants. IMPACT FOR HUMAN MEDICINE Cats metabolize immunosuppressive drugs in a manner similar to humans; therefore, renal transplantation in cats may serve as a desirable model for investigating the effects of renal transplantation in human patients.

  15. Early changes in scores of chronic damage on transplant kidney protocol biopsies reflect donor characteristics, but not future graft function.

    PubMed

    Caplin, Ben; Veighey, Kristin; Mahenderan, Arundathi; Manook, Miriam; Henry, Joanne; Nitsch, Dorothea; Harber, Mark; Dupont, Peter; Wheeler, David C; Jones, Gareth; Fernando, Bimbi; Howie, Alexander J; Veitch, Peter

    2013-01-01

    The amount of irreversible injury on renal allograft biopsy predicts function, but little is known about the early evolution of this damage. In a single-center cohort, we examined the relationship between donor-, recipient-, and transplantation-associated factors and change in a morphometric index of chronic damage (ICD) between protocol biopsies performed at implantation and at 2-3 months. We then investigated whether early delta ICD predicted subsequent biochemical outcomes. We found little evidence to support differences between the study group, who had undergone serial biopsies, and a contemporaneous control group, who had not. In allografts with serial biopsies (n = 162), there was an increase in ICD between implantation (median: 2%, IQR:0-8) and 2-3 months post-transplant (median 8% IQR:4-15; p < 0.0001). Donation from younger or live donors was independently associated with smaller early post-transplant increases in ICD. There was no evidence for a difference in delta ICD between donation after cardiac death vs. donation after brain death, nor association with length of cold ischemia. After adjustment for GFR at the time of the second biopsy, delta ICD after three months did not predict allograft function at one yr. These findings suggest that graft damage develops shortly after transplantation and reflects donor factors, but does not predict future biochemical outcomes.

  16. Inhibitory effects of merocyanine 540-mediated photodynamic therapy on cellular immune functions: A role in the prophylaxis of graft-versus-host disease?

    PubMed

    Traul, Donald L; Sieber, Fritz

    2015-12-01

    Merocyanine 540-mediated photodynamic therapy (MC540-PDT) has been used in clinical trials for the purging of autologous hematopoietic stem cell grafts. When the same combinations of dye and light were applied to human peripheral blood lymphocytes, a broad range of T- and B-cell functions were impaired, prompting speculations about a potential role of MC540-PDT in the prophylaxis of graft-versus-host disease (GVHD). We here report on the effects of MC540-PDT on in vitro functions of murine lymphocytes as well as a preliminary evaluation of MC540-PDT for the prevention of GVHD in murine models of allogeneic bone marrow transplantation. Mixed lymphocyte reactions, proliferative responses to lectins, interleukin-2 and lipopolysaccharide, T-cell-mediated lysis, and NK activity were all inhibited by moderate doses of MC540-PDT. Whether MC540-PDT reduced the incidence and/or the severity of GVHD in murine models of allogeneic hematopoietic stem cell transplantation depended on the composition of the mismatched grafts and the intensity of the preparative regimen. MC540-PDT was only beneficial (i.e. reduced the incidence and/or severity of GVHD) when the spleen cell content of grafts was low and/or the radiation dose of the preparative regimen was not myeloablative, and, therefore, may have encouraged mixed chimerism.

  17. Ethanol exposure induces a delay in the reacquisition of function during head regeneration in Schmidtea mediterranea.

    PubMed

    Lowe, Jesse R; Mahool, Tyler D; Staehle, Mary M

    2015-01-01

    Prenatal exposure to ethanol affects neurodevelopmental processes, leading to a variety of physical and cognitive impairments collectively termed Fetal Alcohol Spectrum Disorders (FASD). The molecular level ethanol-induced alterations that underlie FASD are poorly understood and are difficult to study in mammals. Ethanol exposure has been shown to affect regulation and differentiation of embryonic stem cells in vitro, suggesting that in vivo effects such as FASD could arise from similar alterations of stem cells. In this study, we hypothesize that ethanol exposure affects head regeneration and neuroregeneration in the Schmidtea mediterranea planarian. S. mediterranea freshwater flatworms have remarkable regenerative abilities arising from an abundant population of pluripotent adult somatic stem cells known as neoblasts. Here, we evaluated the mobility-normalized photophobic behavior of ethanol-exposed planaria as an indicator of cognitive function in intact and head-regenerating worms. Our studies show that exposure to 1% ethanol induces a delay in the reacquisition of behavior during head regeneration that cannot be attributed to the effect of ethanol on intact worms. This suggests that the S. mediterranea planarian could provide insight into conserved neurodevelopmental processes that are affected by ethanol and that lead to FASD in humans.

  18. Serial position functions following selective hippocampal lesions in monkeys: Effects of delays and interference✩

    PubMed Central

    Bachevalier, Jocelyne; Wright, Anthony A.; Katz, Jeffrey S.

    2013-01-01

    We examined the role of the hippocampus in list-memory processing. Three rhesus monkeys that had extensive experience in this task and had demonstrated full abstract-concept learning and excellent list memory performance (Katz et al., 2002; Wright et al., 2003) received bilateral neurotoxic hippocampal lesions and were re-tested in the serial list memory task. Effects of delays on memory performance were measured in all monkeys, whereas the effects of proactive interference were assessed in only one. Despite a slight change in performance of one of the three animals during re-learning of the same/different task, selective hippocampal damage had little or no effects on list memory accuracy. In addition, the hippocampal damage did not impact serial list position functions (SPFs) but slightly altered the dynamic of the SPF curves. Finally, even more remarkable was that accurate memory performance of one animal remained intact despite the use of small set size of 8 items that created high proactive interference across lists thereby eliminating any use of familiarity judgments to support performance. Together the findings indicate that, with short list items and extensive training in the task (i.e., reference memory), monkeys with selective hippocampal lesions may be able to use alternative memory processes (i.e., working memory) that are mediated by structures other than the hippocampus. PMID:23246643

  19. Delay differential equations via the matrix Lambert W function and bifurcation analysis: application to machine tool chatter.

    PubMed

    Yi, Sun; Nelson, Patrick W; Ulsoy, A Galip

    2007-04-01

    In a turning process modeled using delay differential equations (DDEs), we investigate the stability of the regenerative machine tool chatter problem. An approach using the matrix Lambert W function for the analytical solution to systems of delay differential equations is applied to this problem and compared with the result obtained using a bifurcation analysis. The Lambert W function, known to be useful for solving scalar first-order DDEs, has recently been extended to a matrix Lambert W function approach to solve systems of DDEs. The essential advantages of the matrix Lambert W approach are not only the similarity to the concept of the state transition matrix in lin ear ordinary differential equations, enabling its use for general classes of linear delay differential equations, but also the observation that we need only the principal branch among an infinite number of roots to determine the stability of a system of DDEs. The bifurcation method combined with Sturm sequences provides an algorithm for determining the stability of DDEs without restrictive geometric analysis. With this approach, one can obtain the critical values of delay, which determine the stability of a system and hence the preferred operating spindle speed without chatter. We apply both the matrix Lambert W function and the bifurcation analysis approach to the problem of chatter stability in turning, and compare the results obtained to existing methods. The two new approaches show excellent accuracy and certain other advantages, when compared to traditional graphical, computational and approximate methods.

  20. Permanence of a predator-prey discrete system with Holling-IV functional response and distributed delays.

    PubMed

    Zhang, X; Wu, Z; Zhou, T

    2016-01-01

    A predator-prey discrete-time model with Holling-IV functional response and distributed delays is investigated in this paper. By using the comparison theorem of the difference equation and some analysis technique, some sufficient conditions are obtained for the permanence of the discrete predator-prey system. Two examples are given to illustrate the feasibility of the obtained result.

  1. 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.

  2. 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

  3. Skin graft

    MedlinePlus

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

  4. Pulsatile cardiac tissue grafts using a novel three-dimensional cell sheet manipulation technique functionally integrates with the host heart, in vivo.

    PubMed

    Furuta, Akira; Miyoshi, Shunichiro; Itabashi, Yuji; Shimizu, Tatsuya; Kira, Shinichiro; Hayakawa, Keiko; Nishiyama, Nobuhiro; Tanimoto, Kojiro; Hagiwara, Yoko; Satoh, Toshiaki; Fukuda, Keiichi; Okano, Teruo; Ogawa, Satoshi

    2006-03-17

    We devised a method of fabricating easily transplantable scaffoldless 3D heart tissue, made with a novel cell-sheet (CS) technology from cultured cardiomyocytes using a fibrin polymer coated dish. In the present study, we tested in vivo electrical communication which is essential for improving heart function between the host heart and the grafted CS. The epicardial surface of the ventricle of an anesthetized open-chest nude rat was ablated by applying a heated metal. Bilayered CS was obtained from neonatal rat primary culture. CS was transplanted onto the injured myocardial surface (sMI) (sMI+sheet group). The rats were allowed to recover for 1 to 4 weeks, to stabilize the grafts. Action potentials (APs) from the excised perfused heart were monitored by the fluorescence signal of di-4ANEPPS with a high speed charge-coupled device camera. The APs were observed under epicardial pacing of the host heart or the CS grafts. The pacing threshold of the current output was measured in the sMI+sheet group and in the nongrafted sMI group at the center of the sMI and in the normal zone (Nz). Bidirectional AP propagation between the sMI and Nz was observed in the sMI+sheet group (n=14), but was blocked at the marginal area of the sMI in the sMI group (n=9). The ratio of the pacing threshold (sMI/Nz) was significantly lower in the sMI+sheet than in the sMI group (3.0+/-0.7, 19.0+/-6.1 respectively P<0.05). There were neither spontaneous nor pacing-induced arrhythmias in these two groups. Bidirectional smooth AP propagation between the host heart and the grafted CS was observed. This finding suggested functional integration of this CS graft with the host heart without serious arrhythmia.

  5. Remarks on the existence and uniqueness of the solutions to stochastic functional differential equations with infinite delay

    NASA Astrophysics Data System (ADS)

    Ren, Yong; Lu, Shiping; Xia, Ningmao

    2008-10-01

    In this paper, we obtain some results on the existence and uniqueness of solutions to stochastic functional differential equations with infinite delay at phase space BC((-[infinity],0];Rd) which denotes the family of bounded continuous Rd-value functions [phi] defined on (-[infinity],0] with norm under non-Lipschitz condition with Lipschitz condition being considered as a special case and a weakened linear growth condition. The solution is constructed by the successive approximation.

  6. Additives enhancing the catalytic properties of lipase from Burkholderia cepacia immobilized on mixed-function-grafted mesoporous silica gel.

    PubMed

    Abaházi, Emese; Boros, Zoltán; Poppe, László

    2014-07-08

    Effects of various additives on the lipase from Burkholderia cepacia (BcL) immobilized on mixed-function-grafted mesoporous silica gel support by hydrophobic adsorption and covalent attachment were investigated. Catalytic properties of the immobilized biocatalysts were characterized in kinetic resolution of racemic 1-phenylethanol (rac-1a) and 1-(thiophen-2-yl)ethan-1-ol (rac-1b). Screening of more than 40 additives showed significantly enhanced productivity of immobilized BcL with several additives such as PEGs, oleic acid and polyvinyl alcohol. Effects of substrate concentration and temperature between 0-100 °C on kinetic resolution of rac-1a were studied with the best adsorbed BcLs containing PEG 20 k or PVA 18-88 additives in continuous-flow packed-bed reactor. The optimum temperature of lipase activity for BcL co-immobilized with PEG 20k found at around 30 °C determined in the continuous-flow system increased remarkably to around 80 °C for BcL co-immobilized with PVA 18-88.

  7. Off-Pump versus On-Pump Coronary Artery Bypass Grafting Outcomes Stratified by Preoperative Renal Function

    PubMed Central

    Zhao, Yue; Lough, Fredrick C.; Schroeder, Elizabeth; Seneff, Michael G.; Brennan, J. Matthew

    2012-01-01

    Clinical trials of off-pump coronary artery bypass grafting (CABG) have largely excluded patients with CKD. Here, we sought to determine whether pump status affects outcomes in patients with CKD. Using a nonrandomized cohort of 742,909 non-emergent, isolated CABG cases, which included 158,561 off-pump cases, in the Society of Thoracic Surgery Database from 2004 through 2009, we evaluated the association between pump status (off-pump versus on-pump) and in-hospital death or incident renal replacement therapy (RRT) across strata of preoperative renal function. We used propensity methods to adjust patient- and center-level analyses for imbalances in baseline patient risk. Patients who received on-pump and off-pump CABG had similar mean age and distribution of preoperative estimated GFR (eGFR). In a propensity-weighted analysis, off-pump CABG was associated with a reduction in the composite in-hospital death or RRT, with patients having lower preoperative renal function exhibiting greater benefit, on average. The risk difference (on-pump minus off-pump) ranged from 0.05 (95% confidence interval, −0.06 to 0.16) per 100 patients for eGFR ≥90 ml/min per 1.73 m2 to 3.66 (95% confidence interval, 2.14–5.18) per 100 patients for eGFR 15–29 ml/min per 1.73 m2. Both component endpoints suggested the same trend. In summary, these data suggest that patients with CKD experience less death or incident RRT when treated with off-pump compared with on-pump CABG. The reduction in incident RRT, not death, drove this effect on the composite among patients with low eGFR. Prospective trials comparing these procedures in patients with impaired preoperative renal function are warranted. PMID:22595302

  8. An efficient approach to obtaining water-compatible and stimuli-responsive molecularly imprinted polymers by the facile surface-grafting of functional polymer brushes via RAFT polymerization.

    PubMed

    Pan, Guoqing; Zhang, Ying; Guo, Xianzhi; Li, Chenxi; Zhang, Huiqi

    2010-11-15

    A new and efficient approach to obtaining molecularly imprinted polymers (MIPs) with both pure water-compatible (i.e., applicable in the pure aqueous environments) and stimuli-responsive binding properties is described, whose proof-of-principle is demonstrated by the facile modification of the preformed MIP microspheres via surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization of N-isopropylacrylamide (NIPAAm). The presence of poly(NIPAAm) (PNIPAAm) brushes on the obtained MIP microspheres was confirmed by FT-IR as well as the water dispersion and static contact angle experiments, and some quantitative information including the molecular weights and polydispersities of the grafted polymer brushes, the thickness of the polymer brush layers, and their grafting densities was provided. In addition, the binding properties of the ungrafted and grafted MIPs/NIPs in both methanol/water (4/1, v/v) and pure water solutions were also investigated. The introduction of PNIPAAm brushes onto the MIP microspheres has proven to significantly improve their surface hydrophilicity and impart stimuli-responsive properties to them, leading to their pure water-compatible and thermo-responsive binding properties. The application of the facile surface-grafting approach, together with the versatility of RAFT polymerization and the availability of many different functional monomers, makes the present methodology a general and promising way to prepare water-compatible and stimuli-responsive MIPs for a wide range of templates.

  9. Improvement of graft function and animal survival by fat emulsion in liver transplant rats.

    PubMed

    Ma, Zheng-Wei; Liu, Li-Dong; Li, Kun; Zhang, Yu-Jun; Dong, Jia-Hong

    2007-01-15

    Nutritional supports are required for liver transplant patients. However, no systematical assessment has been made of the optimal composition of energy yielding substrates in these patients. This study is to evaluate whether mixed energy system consisting of carbohydrate and lipid emulsions is more advantageous over single energy source of glucose for nutritional support in liver transplant recipients and whether structured lipid emulsion (STG) is superior to medium-chain triglyceride/long-chain triglycerides (MCT/LCT) and long-chain triglycerides (LCT) using a total parenteral nutrition model. Liver transplant rats were randomly divided to four groups according to the energy source, i.e. glucose (GLU), MCT/LCT, STG and LCT groups. Sham operated rats served as control. Hepatic function and lipid profile were determined to investigate the roles of lipid emulsion in hepatic function and lipid metabolism. Morphological changes of liver were observed, and nitrogen balance was determined. The results showed that infusion of lipid emulsion was well tolerated. The 1-week survival rate in the lipid emulsion groups was significantly higher than in the GLU group (100% versus 50%, P<0.05); compared with the GLU group, hepatic function recovered quickly and returned to normal level, and morphological alterations were less severer in the lipid emulsion groups, especially in the STG group; the lipid emulsions groups had normal serum TG and TC levels, especially STG and MCT/LCT groups; the lipid emulsions groups achieved a positive nitrogen balance on day 7 compared with the GLU group, and the STG group had the highest nitrogen balance. In conclusion, lipid emulsion is beneficial in improving hepatic function and the recipients' survival and does not influence the lipid metabolism. Mixed energy system consisting of carbohydrate and lipid is more advantageous over single energy source of glucose after liver transplantation, and STG is superior to MCT/LCT and LCT.

  10. [Incomplete paraplegia after delayed diagnostics of motor function deficits. Severe malpractice?].

    PubMed

    Regauer, M; Neu, J

    2013-03-01

    A 72-year-old female patient was transferred to a rehabilitation centre after surgical stabilization of a subtrochanteric femoral fracture. However, adequate mobilization was not possible there and 5 days after transfer deficits in the motor function of both lower extremities were documented for the first time and an initial paraplegia was diagnosed the following day by a neurologist. Magnetic resonance imaging (MRI) revealed the suspicion of an unstable fracture of the seventh thoracic vertebral body 8 days after the initial symptoms, which was confirmed by computed tomography after another 3 days. Surgical decompression and stabilization were performed at a department for neurosurgery 4 days later but incomplete paraplegia persisted permanently. The patient complained about insufficient diagnostic measures at the rehabilitation centre. The expert opinion concluded that it would have been mandatory to investigate the matter of the newly occurring neurological symptoms immediately but this had only been performed after undue delay, which had to be interpreted as a case of medical malpractice. The expert pointed out that it was not possible to provide clear evidence that emergent diagnosis and surgery would have enabled a significantly better outcome.The arbitration board ascertained a lack of examination and argued that prompt and adequate diagnostic measures would have revealed the relevant pathological finding and thus surgery would have been performed immediately. According to the reversal of evidence in favor of the patient it could be assumed that no permanent neurological damage existed when the first neurological symptoms occurred and that emergent surgery at least had the potential to prevent permanent paraplegia. This opinion of the arbitration board is supported by numerous references in the literature.

  11. Dual responsive polymeric nanoparticles prepared by direct functionalization of polylactic acid-based polymers via graft-from ring opening metathesis polymerization.

    PubMed

    Veccharelli, Kate M; Tong, Venus K; Young, Jennifer L; Yang, Jerry; Gianneschi, Nathan C

    2016-01-11

    Polylactic acid (PLA) has found widespread use in plastics and in biomedical applications due to its biodegradability into natural benign products. However, PLA-based materials remain limited in usefulness due to difficulty of incorporating functional groups into the polymer backbone. In this paper, we report a strategy for PLA functionalization that establishes the preparation of highly derivatized materials in which ring opening metathesis polymerization (ROMP) is employed as a graft-from polymerization technique utilizing a norbornene-modified handle incorporated into the PLA backbone. As a demonstration of this new synthetic methodology, a PLA-derived nanoparticle bearing imidazole units protected with a photolabile group was prepared. The morphology of this material could be controllably altered in response to exposure of UV light or acidic pH as a stimulus. We anticipate that this graft-from approach to derivatization of PLA could find broad use in the development of modified, biodegradable PLA-based materials.

  12. Removal of Cd(II) and Pb(II) from wastewater by using triethylenetetramine functionalized grafted cellulose acetate-manganese dioxide composite.

    PubMed

    Yakout, Amr A; El-Sokkary, Ramadan H; Shreadah, Mohamed A; Abdel Hamid, Omnia G

    2016-09-05

    In this manuscript, we have studied the removal of Cd(II) and Pb(II) ions from aqueous solution by using triethylenetetramine functionalized cellulose acetate grafted with the copolymer-manganese dioxide composite. The novel sorbent cellulose was extracted from the mangrove trees (Avicennia marina) and it was then acetylated and grafted with acrylamide. The sorbent composite was designed to interact simultaneously with higher metal loading by complexation-adsorption process. FT-IR, SEM, EDAX and TGA techniques were employed to characterize the cellulose modified composite. Sorption equilibria were established after 30min and their data were described by Langmuir and Freundlich models. The functionalized hybrid cellulose composite showed maximum adsorption capacity 82.06 and 196.84mgg(-1) for Cd(II) and Pb(II), respectively. The studied metal ions were successfully recovered from real wastewater samples of different matrices.

  13. [Glycogen storage of the liver: a determining factor of initial function of the hepatic graft].

    PubMed

    Boudjema, K; Cinqualbre, J; Barguil, Y; Pattou, F; Kerr, J A; Wolf, P; Southard, J H; Jaeck, D

    1991-01-01

    In this study we have investigated the effects of hepatocytes glycogen storage on the quality of livers for transplantation. Rats were fed or fasted for 24 h and hepatocytes isolated and cold stored in UW solution for 24 and 48 hours. Viability of the cells was analyzed by LDH release after 2 hours incubation in L15 with O2. Also, rabbits were fed, fasted (48 h) or glucose fed (48 h) and livers cold stored for 6, 24 and 48 h in UW solution. Functions of the livers were analyzed by isolated perfusion for 2 hours. Hepatocytes from fasted rats released significantly more LDH than hepatocytes from fed rats after 24 and 48 h cold storage. In rabbit livers, fasting depleted glycogen by 85% but had no effect on ATP or glutathione concentration. Livers from fasted rabbits produced similar amount of bile, released similar concentrations of lactate dehydrogenase and aspartate transaminase into the perfusate, maintained similar concentrations of glutathione after 24 hours preservation when compared to fed animals. After 48 h preservation livers from fasted animals were less viable than livers from fed animals and the decrease of liver functions in livers from fasted animals preserved for 48 hours was prevented by feeding glucose. This study shows that liver glycogen storage in hepatocyte is an important metabolite for successful liver preservation. Glycogen may be a source for ATP and antioxydant synthesis during the early period of reperfusion.

  14. Deconvolution analyses with tent functions reveal delayed and long-sustained increases of BOLD signals with acupuncture stimulation.

    PubMed

    Murase, Tomokazu; Umeda, Masahiro; Fukunaga, Masaki; Tanaka, Chuzo; Higuchi, Toshihiro

    2013-01-01

    We used deconvolution analysis to examine temporal changes in brain activity after acupuncture stimulation and assess brain responses without expected reference functions. We also examined temporal changes in brain activity after sham acupuncture (noninsertive) and scrubbing stimulation. We divided 26 healthy right-handed adults into a group of 13 who received real acupuncture with manual manipulation and a group of 13 who received both tactical stimulations. Functional magnetic resonance imaging (fMRI) sequences consisted of four 15-s stimulation blocks (ON) interspersed between one 30-s and four 45-s rest blocks (OFF) for a total scanning time of 270 s. We analyzed data by using Statistical Parametric Mapping 8 (SPM8), MarsBaR, and Analysis of Functional NeuroImages (AFNI) software. For statistical analysis, we used 3dDeconvolve, part of the AFNI package, to extract the impulse response functions (IRFs) of the fMRI signals on a voxel-wise basis, and we tested the time courses of the extracted IRFs for the stimulations. We found stimulus-specific impulse responses of blood oxygen level-dependent (BOLD) signals in various brain regions. We observed significantly delayed and long-sustained increases of BOLD signals in several brain regions following real acupuncture compared to sham acupuncture and palm scrubbing, which we attribute to peripheral nocireceptors, flare responses, and processing of the central nervous system. Acupuncture stimulation induced continued activity that was stronger than activity after the other stimulations. We used tent function deconvolution to process fMRI data for acupuncture stimulation and found delayed increasing and delayed decreasing changes in BOLD signal in the somatosensory areas and areas related to pain perception. Deconvolution analyses with tent functions are expected to be useful in extracting complicated and associated brain activity that is delayed and sustained for a long period after various stimulations.

  15. Effect of discontinuing morning dose of antihypertensive for renal transplant surgery on haemodynamic and early graft functioning: A prospective, double-blind, randomised study

    PubMed Central

    Kumar, Vinod; Arya, Virendra Kumar; Sondekoppam, Rakesh V; Arora, Suman; Minz, Mukut; Garg, Rakesh; Gupta, Nishkarsh

    2017-01-01

    Background and Aims: Antihypertensive drugs are continued until the day of renal transplant surgery. These are associated with increased incidence of hypotension and bradycardia. Hence, this study was designed to evaluate perioperative haemodynamic and early graft functioning in renal recipients with discontinuation of antihypertensive drugs on the morning of surgery. Methods: This prospective, randomised, double-blind study recruited 120 patients. Group 1 patients received placebo tablet while Group 2 patients received usual antihypertensive drugs on the day of surgery. Perioperative haemodynamics and time for reinstitution of antihypertensives were the primary outcome measures. The secondary outcome measures were need for inotropic support and graft function. Perioperative haemodynamics were analysed using ANOVA and Student's t-tests with Bonferroni correction. Fischer's exact test was used for analysis. Results: Systolic blood pressure (SBP) declined, which was more in Group 2. Forty-one patients developed significant hypotension; a correlation was found between the maximum observed hypotension and number of antihypertensive medications (P = 0.003). Four cases had slow graft function (one in Group 1 and three in Group 2). Twenty-eight patients in Group 2 required mephentermine boluses to maintain their SBP compared to 13 patients in Group 1 (P < 0.001). Two patients in Group 2 required dopamine to maintain SBP above 90 mmHg after the establishment of reperfusion as compared to none in Group 1. Conclusion: Single dose of long-acting antihypertensive drugs can be omitted on the morning of surgery without any haemodynamic fluctuations and graft function in controlled hypertensive end-stage renal disease renal transplant patients receiving a combined epidural and general anaesthesia. PMID:28250484

  16. The effect of milrinone on the right ventricular function in patients with reduced right ventricular function undergoing off-pump coronary artery bypass graft surgery.

    PubMed

    Lee, Jong Hwa; Oh, Young Jun; Shim, Yon Hee; Hong, Yong Woo; Yi, Gijong; Kwak, Young Lan

    2006-10-01

    This investigation evaluated the effect of continuous milrinone infusion on right ventricular (RV) function during off-pump coronary artery bypass graft (OPCAB) surgery in patients with reduced RV function. Fifty patients scheduled for OPCAB, with thermodilution RV ejection fraction (RVEF) <35% after anesthesia induction, were randomly allocated to either milrinone (0.5 microg/kg/min) or control (saline) group. Hemodynamic variables and RV volumetric data measured by thermodilution method were collected as follows: after anesthesia induction (T1); 10 min after heart displacement for obtuse marginal artery anastomosis (T2); after pericardial closure (T3). Cardiac index and heart rate increased and systemic vascular resistance significantly decreased in milrinone group at T2. Initially lower RVEF of milrinone group was eventually comparable to control group after milrinone infusion. RVEF did not significantly change at T2 and T3 in both groups. RV end-diastolic volume in milrinone group consistently decreased from the baseline at T2 and T3. Continuous infusion of milrinone without a bolus demonstrated potentially beneficial effect on cardiac output and RV afterload in patients with reduced RV function during OPCAB. However, aggressive augmentation of intravascular volume seems to be necessary to maximize the effect of the milrinone in these patients.

  17. Enhanced equivalence class formation by the delay and relational functions of meaningful stimuli.

    PubMed

    Arntzen, Erik; Nartey, Richard K; Fields, Lanny

    2015-05-01

    Undergraduates in six groups of 10 attempted to form three 3-node 5-member equivalence classes (A → B → C → D → E) under the simultaneous protocol. In five of six groups, all stimuli were abstract shapes; in the PIC group, C stimuli were pictures with the remainder being abstract shapes. Before class formation, participants in the Identity-S and Identity-D groups were given preliminary training to form identity conditional discriminations with the C stimuli using simultaneous and 6 s delayed matching-to-sample procedures, respectively. In the Arbitrary-S and Arbitrary-D groups, before class formation, arbitrary conditional discriminations were formed between C and X stimuli using simultaneous and 6 s delayed matching-to-sample procedures, respectively. With no preliminary training, classes in the PIC and ABS groups were formed by 80% and 0% of participants, respectively. After preliminary training, class formation (yield) increased with delay, regardless of relational type. For each of the two delays, yield was slightly greater after forming arbitrary- instead of identity-relations. Yield was greatest, however, when a class contained a meaningful stimulus (PIC). During failed class formation, probes produced experimenter-defined relations, participant-defined relations, and unsystematic responding; delay, but not the relation type in preliminary training influenced relational and indeterminate responding. These results suggest how meaningful stimuli enhance equivalence class formation.

  18. Delayed puberty.

    PubMed

    Traggiai, Cristina; Stanhope, Richard

    2002-03-01

    Puberty is the acquisition of secondary sexual characteristics associated with a growth spurt and resulting in the attainment of reproductive function. Delayed puberty is diagnosed when there is no breast development by 13.4 years of age in a girl and no testicular enlargement by 14.0 years in a boy. The aetiologies are: (i) pubertal delay, either with constitutional delay of growth and puberty or secondary to chronic illness, and (ii) pubertal failure, with hypogonadotrophic (defect in the hypothalamo-pituitary region) or hypergonadotrophic (secondary to gonadal failure) hypogonadism, or both (secondary to radio/chemotherapy). The investigation includes: history, auxological data and pubertal development examination. Boys usually require treatment and, if they do not respond, investigation. In girls it is appropriate to measure the thyroid function and karyotype first and, if necessary, to offer treatment. If they present with dysmorphic features, or positive familial history, an assessment is required before treatment.

  19. Functional result relating to the positioning of the graft in anterior cruciate ligament reconstruction☆

    PubMed Central

    de Melo Silva Júnior, Otávio; do Nascimento Ohashi, Bruno; de Almeida, Murilo Oliveira; Reis Gonçalves, Murilo

    2015-01-01

    Objective To ascertain the coronal angles for the femoral and tibial tunnels that provide the best postoperative result from anterior cruciate ligament (ACL) reconstruction surgery, through assessing the variables of the IKDC and Lysholm–Tegner questionnaires and the hop test. Methods Sixteen patients with a single unilateral ACL injury who underwent this surgery between 24 and 36 months earlier were evaluated. They were divided into four groups in which the tibial and femoral tunnel angles were greater than or less than 65° in the coronal plane. Results The results demonstrated that a more vertical angle for the tibial tunnel (72°) and a more horizontal angle for the femoral tunnel (60°), with valgus alignment of 12° correlated with the best values for the variables studied. This may indicate that the long-term results from this surgery are excellent. Conclusion A more horizontal femoral angle and a more vertical tibial angle produced better assessments in the tests that were applied and in the functional results evaluated. PMID:26229897

  20. A density dependent delayed predator-prey model with Beddington-DeAngelis type function response incorporating a prey refuge

    NASA Astrophysics Data System (ADS)

    Tripathi, Jai Prakash; Abbas, Syed; Thakur, Manoj

    2015-05-01

    This paper describes a predator-prey model incorporating a prey refuge. The feeding rate of consumers (predators) per consumer (i.e. functional response) is considered to be of Beddington-DeAngelis type. The Beddington-DeAngelis functional response is similar to the Holling-type II functional response but contains an extra term describing mutual interference by predators. We investigate the role of prey refuge and degree of mutual interference among predators in the dynamics of system. The dynamics of the system is discussed mainly from the point of view of permanence and stability. We obtain conditions that affect the persistence of the system. Local and global asymptotic stability of various equilibrium solutions is explored to understand the dynamics of the model system. The global asymptotic stability of positive interior equilibrium solution is established using suitable Lyapunov functional. The dynamical behaviour of the delayed system is further analyzed through incorporating discrete type gestation delay of predator. It is found that Hopf bifurcation occurs when the delay parameter τ crosses some critical value. The analytical results found in the paper are illustrated with the help of numerical examples.

  1. Effect of film thickness on the antifouling performance of poly(hydroxy-functional methacrylates) grafted surfaces.

    PubMed

    Zhao, Chao; Li, Lingyan; Wang, Qiuming; Yu, Qiuming; Zheng, Jie

    2011-04-19

    The development of nonfouling biomaterials to prevent nonspecific protein adsorption and cell/bacterial adhesion is critical for many biomedical applications, such as antithrombogenic implants and biosensors. In this work, we polymerize two types of hydroxy-functional methacrylates monomers of 2-hydroxyethyl methacrylate (HEMA) and hydroxypropyl methacrylate (HPMA) into polymer brushes on the gold substrate via surface-initiated atom transfer radical polymerization (SI-ATRP). We systematically examine the effect of the film thickness of polyHEMA and polyHPMA brushes on their antifouling performance in a wide range of biological media including single-protein solution, both diluted and undiluted human blood serum and plasma, and bacteria culture. Surface plasmon resonance (SPR) results show a strong correlation between antifouling property and film thickness. Too thin or too thick polymer brushes lead to large protein adsorption. Surfaces with the appropriate film thickness of ∼25-45 nm for polyHPMA and ∼20-45 nm for polyHEMA can achieve almost zero protein adsorption (<0.3 ng/cm(2)) from single-protein solution and diluted human blood plasma and serum. For undiluted human blood serum and plasma, polyHEMA brushes at a film thickness of ∼20-30 nm adsorb only ∼3.0 and ∼3.5 ng/cm(2) proteins, respectively, while polyHPMA brushes at a film thickness of ∼30 nm adsorb more proteins of ∼13.5 and ∼50.0 ng/cm(2), respectively. Moreover, both polyHEMA and polyHPMA brushes with optimal film thickness exhibit very low bacteria adhesion. The excellent antifouling ability and long-term stability of polyHEMA and polyHPMA brushes make them, especially for polyHEMA, effective and stable antifouling materials for usage in blood-contacting devices.

  2. Nonlinear Time Delayed Feedback Control of Aeroelastic Systems: A Functional Approach

    NASA Technical Reports Server (NTRS)

    Marzocca, Piergiovanni; Librescu, Liviu; Silva, Walter A.

    2003-01-01

    In addition to its intrinsic practical importance, nonlinear time delayed feedback control applied to lifting surfaces can result in interesting aeroelastic behaviors. In this paper, nonlinear aeroelastic response to external time-dependent loads and stability boundary for actively controlled lifting surfaces, in an incompressible flow field, are considered. The structural model and the unsteady aerodynamics are considered linear. The implications of the presence of time delays in the linear/nonlinear feedback control and of geometrical parameters on the aeroelasticity of lifting surfaces are analyzed and conclusions on their implications are highlighted.

  3. Identification of in vitro parameters predictive of graft function: a study in an animal model of islet transplantation.

    PubMed

    Migliavacca, B; Nano, R; Antonioli, B; Marzorati, S; Davalli, A M; Di Carlo, V; Bertuzzi, F

    2004-04-01

    The quality of human islets is one of the factors decisive for the success of human islet transplantation. Several parameters have been proposed to characterize islet quality, but none of them has been able to predict the fate of a transplant. The aim of our study was to correlate a panel of in vitro parameters for islet viability with their in vivo function after transplantation in nude mice. Islets were obtained after enzymatic digestion of a human pancreas; they were purified from exocrine tissue using a continuous-density gradient. Two aliquots of islets (1000 and 2000 islets) were transplanted under the kidney capsule of diabetic nude mice. The animals were followed for 1 month with repeated measurements of blood glucose and body weight. One month after transplantation, mice were killed and their graft harvested for histologic analysis. In parallel we studied in vitro islet viability with propidium iodide and fura-2, their insulin content, their purity, and their insulin response to glucose upon static incubation. Ten islet preparations were transplanted: 3 out of 10 preparations did not restore normoglycemia; 4 out of 10 normalized glycemia only in mice receiving 2000 islets, and 3 out of 10 fully restore normoglycemia in all mice. The purity of preparations (R(2) = 0.63 and 0.85, respectively, with 1000 and 2000 islets) and the insulin content (R(2) = 0.75 with 2000 IE) correlated with transplant success. These data show that purity of islet preparations and their insulin content should be useful parameters for the selection of islet preparations for transplant purposes.

  4. Grafting in revision rhinoplasty.

    PubMed

    Bussi, M; Palonta, F; Toma, S

    2013-06-01

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

  5. The roles of predator maturation delay and functional response in determining the periodicity of predator-prey cycles.

    PubMed

    Wang, Hao; Nagy, John D; Gilg, Olivier; Kuang, Yang

    2009-09-01

    Population cycles in small mammals have attracted the attention of several generations of theoretical and experimental biologists and continue to generate controversy. Top-down and bottom-up trophic regulations are two recent competing hypotheses. The principal purpose of this paper is to explore the relative contributions of a variety of ecological factors to predator-prey population cycles. Here we suggest that for some species - collared lemmings, snowshoe hares and moose in particular - maturation delay of predators and the functional response of predation appear to be the primary determinants. Our study suggests that maturation delay alone almost completely determines the cycle period, whereas the functional response greatly affects its amplitude and even its existence. These results are obtained from sensitivity analysis of all parameters in a mathematical model of the lemming-stoat delayed system, which is an extension of Gilg's model. Our result may also explain why lemmings have a 4-year cycle whereas snowshoe hares have a 10-year cycle. Our parameterized model supports and extends May's assertion that time delay impacts cycle period and amplitude. Furthermore, if maturation periods of predators are too short or too long, or the functional response resembles Holling Type I, then population cycles do not appear; however, suitable intermediate predator maturation periods and suitable functional responses can generate population cycles for both prey and predators. These results seem to explain why some populations are cyclic whereas others are not. Finally, we find parameterizations of our model that generate a 38-year population cycle consistent with the putative cycles of the moose-wolf interactions on Isle Royale, Michigan.

  6. A note on the neutral stochastic functional differential equation with infinite delay and Poisson jumps in an abstract space

    NASA Astrophysics Data System (ADS)

    Ren, Yong; Chen, Li

    2009-08-01

    In this note, we prove the existence and uniqueness of the solution to neutral stochastic functional differential equation with infinite delay and Poisson jumps in the phase space B with non-Lipschitz coefficients. The known results that appeared in the studies by Ren and Xia [Appl. Math. Comput. 210, 72 (2009); Ren and XiaAppl. Math. Comput. 214, 457 (2009)] and Xu and Hu [Acta Appl. Math. (unpublished)] are generalized and improved. An example is provided to illustrate the theory.

  7. Delayed Video Self-Recognition in Children with High Vo Functioning Autism and Asperger's Disorder

    ERIC Educational Resources Information Center

    Dissanayake, Cheryl; Shembrey, Joh; Suddendorf, Thomas

    2010-01-01

    Two studies are reported which investigate delayed video self-recognition (DSR) in children with autistic disorder and Asperger's disorder relative to one another and to their typically developing peers. A secondary aim was to establish whether DSR ability is dependent on metarepresentational ability. Children's verbal and affective responses to…

  8. Trajectories of Developmental Functioning among Children of Adolescent Mothers: Factors Associated with Risk for Delay

    ERIC Educational Resources Information Center

    Jahromi, Laudan B.; Umaña-Taylor, Adriana J.; Updegraff, Kimberly A.; Zeiders, Katharine H.

    2016-01-01

    Children of adolescent mothers are at risk for developmental delays. Less is known about the heterogeneity in these children's developmental trajectories, and factors associated with different patterns of development. This longitudinal study used latent class growth analysis (LCGA) to identify distinct trajectories in children of Mexican-origin…

  9. Natural Killer Cell Subsets and IL-2, IL-15, and IL-18 Genes Expressions in Chronic Kidney Allograft Dysfunction and Graft Function in Kidney Allograft Recipients

    PubMed Central

    Assadiasl, S.; Sepanjnia, A.; Aghili, B.; Nafar, M.; Ahmadpoor, P.; Pourrezagholi, F.; Parvin, M.; Shahlaee, A.; Nicknam, M. H.; Amirzargar, A.

    2016-01-01

    Background: While acute rejection and early graft loss rates have decreased substantially over the past four decades, progressive chronic allograft dysfunction (CAD) still remains a common cause of late graft loss in kidney transplant recipients. Objective: This study was conducted to investigate the percentage of natural killer (NK) cell subsets and IL-2, 15 and 18 genes expression in two groups of CAD and well-function graft (WFG) recipients. Methods: 30 renal allograft recipients with biopsy-proven interstitial fibrosis/tubular atrophy (IF/TA) and impaired renal function, and 30 sex- and age-matched WFG patients were enrolled in this study. The percentage of NK cell subsets including NK CD56bright and NK CD56dim cells were determined by flowcytometry; IL-2, IL-15, and IL-18 genes expressions were assessed by real-time PCR. Results: Compared to WFG patients, there was a significant (p<0.05) increase in the percentage of NK CD56bright cells in CAD patients. However, the difference in percentage of NK CD56dim cells or CD56dim/CD56bright ratio between the studied groups was not significant. In addition, IL-2, 15 and 18 genes expressions were almost similar in CAD and WFG patients. Conclusion: We found higher percentages of NK CD56bright subset in kidney transplant recipients with CAD without considerable changes in related cytokines’ gene expression, suggesting a possible defect of NK cells maturation in these patients. PMID:28078060

  10. Self-monitoring bypass grafts enable early intervention

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  11. Interventions in Infrainguinal Bypass Grafts

    SciTech Connect

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

    2006-02-15

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

  12. Long-term facial nerve function following facial reanimation after translabyrinthine vestibular schwannoma surgery: A comparison between sural grafting and VII-XII anastomosis.

    PubMed

    Wang, Zhaoyan; Zhang, Zhihua; Huang, Qi; Yang, Jun; Wu, Hao

    2013-07-01

    The aim of this study was to compare the recovery of long-term facial nerve function between patients who received sural grafts and those who underwent hypoglossal-facial anastomosis techniques following translabyrinthine vestibular schwannoma surgery. This study included 25 patients with vestibular schwannomas treated with translabyrinthine tumor removal. All patients had large tumors with a mean tumor size of 3.12 cm. Of these patients, six had progressive tumor enlargement symptoms and had been treated previously with stereotactic irradiation. Preoperatively, all patients had normal facial functions, and total tumor removal with a translabyrinthine approach was achieved in all cases. During surgery, the facial nerve was interrupted in all 25 patients. Two types of facial reanimation were performed. Sural grafts were placed in 13 patients and hypoglossal-facial (VII-XII) anastomosis was performed in the other 12. Facial nerve function and surgical outcomes were observed upon discharge, in the short term (one year following surgery), and in the long term (three years following surgery). Total facial paresis was observed in all patients upon discharge. In the sural graft group, House-Brackmann grade III facial function was achieved in four patients upon short-term evaluation and in ten upon long-term evaluation, while House-Brackmann grade IV facial function was achieved in nine patients upon short-term evaluation and three in the long term. In the VII-XII anastomosis group, House-Brackmann grade III facial function was achieved in two patients in the short term and eight in the long term, and House-Brackmann grade IV facial function was achieved in ten patients in the short term and four in the long term. There was a statistically significant difference in the facial recovery results between the short- and long-term follow-up periods. The sural graft group exhibited a marked improvement in results compared with the VII-XII anastomosis group, but no statistically

  13. Delayed intervention with transplants and neurotrophic factors supports recovery of forelimb function after cervical spinal cord injury in adult rats.

    PubMed

    Lynskey, James V; Sandhu, Faheem A; Sandhu, Faheen A; Dai, Hai-Ning; Dai, Hail-Ning; McAtee, Marietta; Slotkin, Jonathan R; Slotkin, Jon R; MacArthur, Linda; Bregman, Barbara S

    2006-05-01

    The adult central nervous system is capable of considerable anatomical reorganization and functional recovery after injury. Functional outcomes, however, vary greatly, depending upon size and location of injury, type and timing of intervention, and type of recovery and plasticity evaluated. The present study was undertaken to assess the recovery of skilled and unskilled forelimb function in adult rats after a C5/C6 spinal cord over-hemisection and delayed intervention with fetal spinal cord transplants and neurotrophins. Recovery of forelimb function was evaluated during both target reaching (a skilled behavior) and vertical exploration (an unskilled behavior). Anatomical tracing and immunohistochemistry were used to assess the growth of descending raphespinal, corticospinal, and rubrospinal fibers at the injury site, tracts that normally confer forelimb function. Delayed intervention with transplants and either brain-derived neurotrophic factor (BDNF) or neurotrophin-3 (NT-3) restored skilled left forelimb reaching to pre-injury levels. Animals showed recovery of normal reaching movements rather than compensation with abnormal movements. Transplants and NT-3 also improved right forelimb use during an unskilled vertical exploration, but not skilled right reaching. Intervention with fetal transplant tissue supported the growth of descending serotonergic, corticospinal, and rubrospinal fibers into the transplant at the lesion site. The addition of neurotrophins, however, did not significantly increase axonal growth at the lesion site. These studies suggest that the recovery of skilled and unskilled forelimb use is possible after a large cervical spinal cord injury following delayed intervention with fetal spinal cord and neurotrophins. Plasticity of both spared and axotomized descending pathways likely contributes to the functional recovery observed.

  14. New Functionalities of PA6,6 Fabric Modified by Atmospheric Pressure Plasma and Grafted Glycidyl Methacrylate Derivatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative atmospheric pressure plasma was utilized to activate surface of PA 6,6 fabrics followed by graft copolymerization of glycidyl methacrylate (GMA) and further reacted with triethylene tetramine (TETA), quaternary ammonium chitosan (HTCC) or cyclodextrin (CD). The inner CD cavity was complexe...

  15. Short-term family-centered workshop for children with developmental delays enhances family functioning and satisfaction

    PubMed Central

    Hsieh, Ru-Lan; Hsieh, Wen-Huei; Lee, Wen-Chung

    2016-01-01

    Abstract We investigated the clinical efficacy on family functioning and parental satisfaction of a short-term family-centered workshop for children with developmental delays. A total of 32 children with developmental delays and their parents participated in 2-hour weekly group therapy sessions over 6 weeks. The workshop was conducted by rehabilitation professionals and teachers using a family-centered multidisciplinary approach. Both before and after the 6-week workshop, the parents were administered the Pediatric Quality of Life Inventory (PedsQL) Family Impact Module, the PedsQL Healthcare Satisfaction Module, the Hospital Anxiety and Depression Scale, and the World Health Organization Quality of Life brief assessment instrument. Overall satisfaction with the workshop was also evaluated. Significant improvements were noted in physical aspect (P = 0.03), communication (P = 0.002), and daily activities (P = 0.04) in the PedsQL Family Impact Module, and in communication (P = 0.03) and technical skills (P = 0.05) in the PedsQL Healthcare Satisfaction Module. Overall satisfaction with the workshop was rated as very high. There was no significant effect on psychological distress or quality of life. Short-term family-centered workshops for children with developmental delays improved family functioning and the parental perception of satisfaction, including health care satisfaction. PMID:27495025

  16. Chronic Alcohol Ingestion Delays T Cell Activation and Effector Function in Sepsis

    PubMed Central

    Margoles, Lindsay M.; Mittal, Rohit; Klingensmith, Nathan J.; Lyons, John D.; Liang, Zhe; Serbanescu, Mara A.; Wagener, Maylene E.

    2016-01-01

    Sepsis is the leading cause of death in intensive care units in the US, and it is known that chronic alcohol use is associated with higher incidence of sepsis, longer ICU stays, and higher mortality from sepsis. Both sepsis and chronic alcohol use are associated with immune deficits such as decreased lymphocyte numbers, impaired innate immunity, delayed-type hypersensitivity reactions, and susceptibility to infections; however, understanding of specific pathways of interaction or synergy between these two states of immune dysregulation is lacking. This study therefore sought to elucidate mechanisms underlying the immune dysregulation observed during sepsis in the setting of chronic alcohol exposure. Using a murine model of chronic ethanol ingestion followed by sepsis induction via cecal ligation and puncture, we determined that while CD4+ and CD8+ T cells isolated from alcohol fed mice eventually expressed the same cellular activation markers (CD44, CD69, and CD43) and effector molecules (IFN-γ, TNF) as their water fed counterparts, there was an overall delay in the acquisition of these phenotypes. This early lag in T cell activation was associated with significantly reduced IL-2 production at a later timepoint in both the CD4+ and CD8+ T cell compartments in alcohol sepsis, as well as with a reduced accumulation of CD8dim activated effectors. Taken together, these data suggest that delayed T cell activation may result in qualitative differences in the immune response to sepsis in the setting of chronic alcohol ingestion. PMID:27861506

  17. Delayed soil thawing affects root and shoot functioning and growth in Scots pine.

    PubMed

    Repo, Tapani; Lehto, Tarja; Finér, Leena

    2008-10-01

    In boreal regions, soil can remain frozen after the start of the growing season. We compared relationships between root characteristics and water relations in Scots pine (Pinus sylvestris L.) saplings subjected to soil frost treatments before and during the first week of the growing period in a controlled environment experiment. Delayed soil thawing delayed the onset of sap flow or totally blocked it if soil thawing lagged the start of the growing period by 7 days. This effect was reflected in the electrical impedance of needles and trunks and in the relative electrolyte leakage of needles. Prolonged soil frost reduced or completely inhibited root growth. In unfrozen soil, limited trunk sap flow was observed despite unfavorable aboveground growing conditions (low temperature, low irradiance, short photoperiod). Following the earliest soil thaw, sap flow varied during the growing season, depending on light and temperature conditions, phenological stage of the plant and the amount of live needles in the canopy. The results suggest that delayed soil thawing can reduce tree growth, and if prolonged, it can be lethal.

  18. Pretreatment dropout as a function of treatment delay and client variables.

    PubMed

    Festinger, D S; Lamb, R J; Kountz, M R; Kirby, K C; Marlowe, D

    1995-01-01

    Utilizing a retrospective analysis we examined factors correlated with preintake dropout in patients phoning to make intake appointments for cocaine treatment. Inquiries of 235 individuals calling our outpatient cocaine treatment program over a 7-month period were analyzed for relationships between patient age and gender; residence in the city where the program is located; marital status; referral source; reported problems with alcohol, marijuana, and heroin; reported last use of cocaine or other illicit stimulants; assigned counselor gender; person who made the appointment; days to the intake appointment; and attending the scheduled intake session. Only days to appointment was significantly (Wald = 12.4587, df = 1, p < .05 and chi 2 = 17.7, df = 8, p < .05) correlated with attending the scheduled intake session. Appointments scheduled the same day differed significantly (chi 2 = 4.3, n = 235, df = 1, p < .05) from appointments scheduled later. This suggests that client and situational variables are not significantly related to initial attendance and enhances the significance of systemic variables that are under a clinic's control, such as appointment delay. The results indicate that the longer the delay between the initial phone contact and the scheduled appointment, the less likely a client is to attend an appointment. Further, they suggest that the greatest decrease in initial attendance occurs in the first 24 hours following the phone inquiry. Taking a "microscopic" look at the appointment delay variable is valuable in understanding and addressing preintake dropout.

  19. Delayed evacuatory function due to specific smooth muscle reactivity in the gastrointestinal tracts of tacrine-treated rats.

    PubMed

    Krustev, A; Sirakov, V; Turiiski, V; Getova, D; Velkova, K; Prissadova, N

    2008-01-01

    Most of the side effects induced by tacrine are associated with the gastrointestinal (GI) tract. The aim of the study was to analyze the nature of radiographically registered, tacrine-induced changes in evacuatory function, as well as to find a possible correlation with the immediate in vitro action of the drug on smooth muscles from the GI tracts of rats. The tacrine dose we used reliably delayed GI passage: contrast matter was not fully evacuated, predominantly from the stomach and cecum. The delay resulted from changes in tone and peristaltic activity, specific for the various regions of the tract. These changes were associated with a superposing of the responses due to the anticholinesterase and noncholinergic action of tacrine.

  20. Atypical delayed auditory feedback effect and Lombard effect on speech production in high-functioning adults with autism spectrum disorder.

    PubMed

    Lin, I-Fan; Mochida, Takemi; Asada, Kosuke; Ayaya, Satsuki; Kumagaya, Shin-Ichiro; Kato, Masaharu

    2015-01-01

    Individuals with autism spectrum disorder (ASD) show impaired social interaction and communication, which may be related to their difficulties in speech production. To investigate the mechanisms of atypical speech production in this population, we examined feedback control by delaying the auditory feedback of their own speech, which degraded speech fluency. We also examined feedforward control by adding loud pink noise to the auditory feedback, which led to increased vocal effort in producing speech. The results of Japanese speakers show that, compared with neurotypical (NT) individuals, high-functioning adults with ASD (including Asperger's disorder, autistic disorder, and pervasive developmental disorder not otherwise specified) were more affected by delayed auditory feedback but less affected by external noise. These findings indicate that, in contrast to NT individuals, those with ASD relied more on feedback control than on feedforward control in speech production, which is consistent with the hypothesis that this population exhibits attenuated Bayesian priors.

  1. Improving the diagnostic criteria for primary liver graft non-function in adults utilizing standard and transportable laboratory parameters. An outcome based analysis.

    PubMed

    Al-Freah, Mohammad A B; McPhail, Mark J W; Dionigi, Elena; Foxton, Matthew R; Auzinger, Georg; Rela, Mohamed; Wendon, Julia A; O'Grady, John G; Heneghan, Michael A; Heaton, Nigel D; Bernal, William

    2017-02-15

    Current diagnostic criteria for primary non-function (PNF) of liver grafts are based on clinical experience rather than statistical methods. A retrospective, single centre study was conducted of all adults (n=1,286) who underwent primary liver transplant 2000-2008 in our centre. Laboratory variable during the first post-liver transplant week were analysed. Forty two patients (3.7%) had 2-week graft failure. Transplant albumin, day-1 AST, day-1 lactate, day-3 bilirubin, day-3 INR and day-7 AST were independently associated with PNF on multivariate logistic regression. PNF score =(0.000280*D1AST)+(0.361*D1 Lactate)+(0.00884*D3 Bilirubin)+(0.940*D 3 INR)+(0.00153*D7 AST)-(0.0972*TxAlbumin)-4.5503. ROC analysis showed the model AUROC of 0.912 (0.889 -0.932) was superior to the current United Kingdom (UK) PNF criteria of 0.669 (0.634-0.704, p<0.0001). When applied to a validation cohort (n=386, 34.4% patients) the model had AUROC of 0.831 (0.789 -0.867) compared to the UK EGD criteria of 0.674 (0.624-0.721). The new model performed well after exclusion of patients with marginal grafts and when modified to include variables from the first three post-LT days only (AUROC of 0.818, 0.776-0.856, p=0.001). This model is superior to the current UK PNF criteria and is based on statistical methods. The model is also applicable to recipients of all types of grafts (marginal and non-marginal). This article is protected by copyright. All rights reserved.

  2. Restricted primitive model for electrolyte solutions in slit-like pores with grafted chains: microscopic structure, thermodynamics of adsorption, and electric properties from a density functional approach.

    PubMed

    Pizio, Orest; Sokołowski, Stefan

    2013-05-28

    We apply a density functional theory to describe properties of a restricted primitive model of an ionic fluid in slit-like pores. The pore walls are modified by grafted chains. The chains are built of uncharged or charged segments. We study the influence of modification of the pore walls on the structure, adsorption, ion selectivity, and the electric double layer capacitance of ionic fluid under confinement. The brush built of uncharged segments acts as a collection of obstacles in the walls vicinity. Consequently, separation of charges requires higher voltages, in comparison to the models without brushes. At high grafting densities the formation of crowding-type structure is inhibited. The double layer structure becomes more complex in various aspects, if the brushes are built of charged segments. In particular, the evolution of the brush height with the bulk fluid density and with the charge on the walls depends on the length of the blocks of charged spheres as well as on the distribution of charged species along chains. We also investigated how the dependence of the double layer capacitance on the electrostatic potential (or on the charge on the walls) changes with grafting density, the chain length, distribution of charges along the chain, the bulk fluid density, and, finally, with the pore width. The shape of the electric double layer capacitance vs. voltage changes from a camel-like to bell-like shape, if the bulk fluid density changes from low to moderate and high. If the bulk density is appropriately chosen, it is possible to alter the shape of this curve from the double hump to single hump by changing the grafting density. Moreover, in narrow pores one can observe the capacitance curve with even three humps for a certain set of parameters describing brush. This behavior illustrates how strong the influence of brushes on the electric double layer properties can be, particularly for ionic fluids in narrow pores.

  3. Hot executive function following moderate-to-late preterm birth: altered delay discounting at 4 years of age.

    PubMed

    Hodel, Amanda S; Brumbaugh, Jane E; Morris, Alyssa R; Thomas, Kathleen M

    2016-03-01

    Interest in monitoring long-term neurodevelopmental outcomes of children born moderate-to-late preterm (32-36 weeks gestation) is increasing. Moderate-to-late preterm birth has a negative impact on academic achievement, which may relate to differential development of executive function (EF). Prior studies reporting deficits in EF in preterm children have almost exclusively assessed EF in affectively neutral contexts in high-risk preterm children (< 32 weeks gestation). Disrupted function in motivational or emotionally charged contexts (hot EF) following preterm birth remains uninvestigated, despite evidence that preterm children show differential development of neural circuitry subserving hot EF, including reduced orbitofrontal cortex volume. The present study is the first to examine whether low-risk, healthy children born moderate-to-late preterm exhibit impairments in the development of hot EF. Preterm children at age 4.5 years were less likely to choose larger, delayed rewards across all levels of reward magnitude on a delay discounting task using tangible rewards, but performed more similarly to their full-term peers on a delay aversion task involving abstract rewards and on measures of cool EF. The relationship between gestational age at birth and selection of delayed rewards extended across the entire gestational age range of the sample (32-42 weeks), and remained significant after controlling for intelligence and processing speed. Results imply that there is not a finite cut-off point at which children are spared from potential long-term neurodevelopmental effects of PT birth. Further investigation of reward processing and hot EF in individuals with a history of PT birth is warranted given the susceptibility of prefrontal cortex development to early environmental variations.

  4. Comparing Teacher-Directed and Computer-Assisted Constant Time Delay for Teaching Functional Sight Words to Students with Moderate Intellectual Disability

    ERIC Educational Resources Information Center

    Coleman, Mari Beth; Hurley, Kevin J.; Cihak, David F.

    2012-01-01

    The purpose of this study was to compare the effectiveness and efficiency of teacher-directed and computer-assisted constant time delay strategies for teaching three students with moderate intellectual disability to read functional sight words. Target words were those found in recipes and were taught via teacher-delivered constant time delay or…

  5. Loss of LORELEI function in the pistil delays initiation but does not affect embryo development in Arabidopsis thaliana.

    PubMed

    Tsukamoto, Tatsuya; Palanivelu, Ravishankar

    2010-11-01

    Double fertilization, uniquely observed in plants, requires successful sperm cell delivery by the pollen tube to the female gametophyte, followed by migration, recognition and fusion of the two sperm cells with two female gametic cells. The female gametophyte not only regulates these steps but also controls the subsequent initiation of seed development. Previously, we reported that loss of LORELEI, which encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein, in the female reproductive tissues causes a delay in initiation of seed development. From these studies, however, it was unclear if embryos derived from fertilization of lre-5 gametophytes continued to lag behind wild type during seed development. Additionally, it was not determined if the delay in initiation of seed development had any lingering effects during seed germination. Finally, it was not known if loss of LORELEI function affects seedling development given that LORELEI is expressed in eight-day-old seedlings. Here, we showed that despite a delay in initiation, lre-5/lre-5 embryos recover, becoming equivalent to the developing wild-type embryos beginning at 72 hours after pollination. Additionally, lre-5/lre-5 seed germination, and seedling and root development are indistinguishable from wild type indicating that loss of LORELEI is tolerated, at least under standard growth conditions, in vegetative tissues.

  6. Loss of LORELEI function in the pistil delays initiation but does not affect embryo development in Arabidopsis thaliana

    PubMed Central

    Tsukamoto, Tatsuya

    2010-01-01

    Double fertilization, uniquely observed in plants, requires successful sperm cell delivery by the pollen tube to the female gametophyte, followed by migration, recognition and fusion of the two sperm cells with two female gametic cells. The female gametophyte not only regulates these steps but also controls the subsequent initiation of seed development. Previously, we reported that loss of LORELEI, which encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein, in the female reproductive tissues causes a delay in initiation of seed development. From these studies, however, it was unclear if embryos derived from fertilization of lre-5 gametophytes continued to lag behind wild-type during seed development. Additionally, it was not determined if the delay in initiation of seed development had any lingering effects during seed germination. Finally, it was not known if loss of LORELEI function affects seedling development given that LORELEI is expressed in eight-day-old seedlings. Here, we showed that despite a delay in initiation, lre-5/lre-5 embryos recover, becoming equivalent to the developing wild-type embryos beginning at 72 hours after pollination. Additionally, lre-5/lre-5 seed germination, and seedling and root development are indistinguishable from wild-type indicating that loss of LORELEI is tolerated, at least under standard growth conditions, in vegetative tissues. PMID:21051955

  7. Radiation grafting on natural films

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  8. The graft-versus-host reaction and immune function. II. Recruitment of pre-T-cells in vivo by graft-versus-host-induced dysplastic thymuses following irradiation and bone marrow treatment

    SciTech Connect

    Seddik, M.; Seemayer, T.A.; Lapp, W.S.

    1984-03-01

    The graft-versus-host (GVH) reaction induces thymic dysplasia and an arrest in T cell differentiation. Studies were performed to test the effect of irradiation and reconstitution with bone marrow on GVH-induced thymic dysplasia and T cell differentiation. GVH reactions were induced in CBAxAF1 adult mice by the injection of A strain lymphoid cells. All GVH-reactive mice were immunosuppressed by day 7 after GVH induction and thymic dysplasia was evident by day 24. Forty days after the induction of the GVH reaction the mice were irradiated (850 rads) and repopulated with 10-15 X 10(6) syngeneic or parental bone marrow cells. Thirty days after irradiation and bone marrow reconstitution, GVH-reactive mice were used for histological and functional studies. These mice displayed near-normal thymus morphology with scattered epithelial cells in the medulla, and normal numbers of Thy-1-positive cells. Donor cells had totally repopulated thymuses of irradiated bone marrow reconstituted mice by day 19 after irradiation. T helper cell function did not recover in the reconstituted mice. These results suggest that (1) the process responsible for GVH-induced thymic dysplasia is radiosensitive, and (2) the thymus has the potential to regenerate a normal structure, but fails to regain normal function.

  9. Multiple periodic solutions of a delayed predator-prey model with non-monotonic functional response and stage structure.

    PubMed

    Liu, Yingyuan; Zhang, Xiaolan; Zhou, Tiejun

    2014-01-01

    The paper studies a periodic and delayed predator-prey system with non-monotonic functional responses and stage structure. In the system, both the predator and prey are divided into immature individuals and mature individuals by two fixed ages. It is assumed that the immature predators cannot attack preys, and the case of the mature predators attacking the immature preys is also ignored. Based on Mawhin's coincidence degree, sufficient conditions are obtained for the existence of two positive periodic solutions of the system. An example is presented to illustrate the feasibility of the main results.

  10. Multistability of neural networks with discontinuous non-monotonic piecewise linear activation functions and time-varying delays.

    PubMed

    Nie, Xiaobing; Zheng, Wei Xing

    2015-05-01

    This paper is concerned with the problem of coexistence and dynamical behaviors of multiple equilibrium points for neural networks with discontinuous non-monotonic piecewise linear activation functions and time-varying delays. The fixed point theorem and other analytical tools are used to develop certain sufficient conditions that ensure that the n-dimensional discontinuous neural networks with time-varying delays can have at least 5(n) equilibrium points, 3(n) of which are locally stable and the others are unstable. The importance of the derived results is that it reveals that the discontinuous neural networks can have greater storage capacity than the continuous ones. Moreover, different from the existing results on multistability of neural networks with discontinuous activation functions, the 3(n) locally stable equilibrium points obtained in this paper are located in not only saturated regions, but also unsaturated regions, due to the non-monotonic structure of discontinuous activation functions. A numerical simulation study is conducted to illustrate and support the derived theoretical results.

  11. Proximal Tibial Bone Graft

    MedlinePlus

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

  12. Verbal Control of Delay Behavior in Two-Year-Old Boys as a Function of Social Class

    ERIC Educational Resources Information Center

    Golden, Mark; And Others

    1977-01-01

    Attempted to determine (1) whether children's performance on Luria-type delay tasks is related to social class, IQ, and age; (2) whether performance is consistent or reliable on different delay tasks and at different ages; and (3) whether children's performance is related to the type of delay task and length of delay interval. (Author/SB)

  13. Surface functionalization of Cu-Ni alloys via grafting of a bactericidal polymer for inhibiting biocorrosion by Desulfovibrio desulfuricans in anaerobic seawater.

    PubMed

    Yuan, S J; Liu, C K; Pehkonen, S O; Bai, R B; Neoh, K G; Ting, Y P; Kang, E T

    2009-01-01

    A novel surface modification technique was developed to provide a copper nickel alloy (M) surface with bactericidal and anticorrosion properties for inhibiting biocorrosion. 4-(chloromethyl)-phenyl tricholorosilane (CTS) was first coupled to the hydroxylated alloy surface to form a compact silane layer, as well as to confer the surface with chloromethyl functional groups. The latter allowed the coupling of 4-vinylpyridine (4VP) to generate the M-CTS-4VP surface with biocidal functionality. Subsequent surface graft polymerization of 4VP, in the presence of benzoyl peroxide (BPO) initiator, from the M-CTS-4VP surface produced the poly(4-vinylpyridine) (P(4VP)) grafted surface, or the M-CTS-P(4VP) surface. The pyridine nitrogen moieties on the M-CTS-P(4VP) surface were quaternized with hexylbromide to produce a high concentration of quaternary ammonium groups. Each surface functionalization step was ascertained by X-ray photoelectron spectroscopy (XPS) and static water contact angle measurements. The alloy with surface-quaternized pyridinium cation groups (N+) exhibited good bactericidal efficiency in a Desulfovibrio desulfuricans-inoculated seawater-based modified Barr's medium, as indicated by viable cell counts and fluorescence microscopy (FM) images of the surface. The anticorrosion capability of the organic layers was verified by the polarization curve and electrochemical impedance spectroscopy (EIS) measurements. In comparison, the pristine (surface hydroxylated) Cu-Ni alloy was found to be readily susceptible to biocorrosion under the same environment.

  14. Early and Delayed Effect of Functional Endoscopic Sinus Surgery on Intraocular Pressure

    PubMed Central

    El-Anwar, Mohammad Waheed; Abdelhady, Mohammad; Amer, Hazem Saeed; Ghali, Manar A.

    2016-01-01

    Introduction Due to the close anatomical relationship between the paranasal sinuses and the orbit, involvement or injury of the orbit from paranasal sinuses procedures may occur. Objectives We aimed to study the early and delayed effect of endoscopic sinus surgery on intraocular pressure (IOP). Methods We included in the study 38 patients with chronic rhinosinusitis (CRS), undergoing FESS. We performed FESS with the standard anterior to posterior approach. We measured IOP at the same time one day before surgery as well as day 1 and 6 weeks after surgery. Results One day after surgery, mean IOP in the right eye was 14.176 ± 1.91 mm Hg and in the left eye was 13.79 ± 2.42 mm Hg with statistically non-significant difference from preoperative values. Six weeks postoperative, the mean IOP in the right eye was 15.14 ± 2.28 mm Hg. The difference between the mean preoperative and postoperative IOP values was found to be statistically significant (p = 0.0012). While in the left eye, mean postoperative IOP was 15.14 + 2.23mm Hg. The difference between the mean preoperative and postoperative IOP values was also found to be highly statistically significant (p = 0.0005). Conclusion Delayed significant increase in IOP can occur after FESS, Thus, special measures must be taken to reduce IOP to protect the patient́s eye from the risk of increased IOP, especially in patients with glaucoma. PMID:27746840

  15. A comparison of self-assembly and hydrogel encapsulation as a means to engineer functional cartilaginous grafts using culture expanded chondrocytes.

    PubMed

    Mesallati, Tariq; Buckley, Conor T; Kelly, Daniel J

    2014-01-01

    Despite an increased interest in the use of hydrogel encapsulation and cellular self-assembly (often termed "self-aggregating" or "scaffold-free" approaches) for tissue-engineering applications, to the best of our knowledge, no study to date has been undertaken to directly compare both approaches for generating functional cartilaginous grafts. The objective of this study was to directly compare self-assembly (SA) and agarose hydrogel encapsulation (AE) as a means to engineer such grafts using passaged chondrocytes. Agarose hydrogels (5 mm diameter × 1.5 mm thick) were seeded with chondrocytes at two cell seeding densities (900,000 cells or 4 million cells in total per hydrogel), while SA constructs were generated by adding the same number of cells to custom-made molds. Constructs were either supplemented with transforming growth factor (TGF)-β3 for 6 weeks, or only supplemented with TGF-β3 for the first 2 weeks of the 6 week culture period. The SA method was only capable of generating geometrically uniform cartilaginous tissues at high seeding densities (4 million cells). At these high seeding densities, we observed that total sulphated glycosaminoglycan (sGAG) and collagen synthesis was greater with AE than SA, with higher sGAG retention also observed in AE constructs. When normalized to wet weight, however, SA constructs exhibited significantly higher levels of collagen accumulation compared with agarose hydrogels. Furthermore, it was possible to engineer such functionality into these tissues in a shorter timeframe using the SA approach compared with AE. Therefore, while large numbers of chondrocytes are required to engineer cartilaginous grafts using the SA approach, it would appear to lead to the faster generation of a more hyaline-like tissue, with a tissue architecture and a ratio of collagen to sGAG content more closely resembling native articular cartilage.

  16. Siloxane-grafted membranes

    DOEpatents

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

    1989-10-31

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

  17. Siloxane-grafted membranes

    DOEpatents

    Friesen, Dwayne T.; Obligin, Alan S.

    1989-01-01

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

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

    PubMed

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

    2013-01-14

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

  19. Coronary Artery Bypass Grafting

    MedlinePlus

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

  20. Delayed administration of the GLP-1 receptor agonist liraglutide improves metabolic and functional recovery after cerebral ischemia in rats.

    PubMed

    Dong, Wenbin; Miao, Yunping; Chen, Aiying; Cheng, Min; Ye, Xiaodi; Song, Fahuan; Zheng, Gaoli

    2017-02-22

    Glucagon-like peptide 1 receptor (GLP-1R) agonists administered before or immediately after induction of experimental stroke have been shown to provide acute neuroprotection. Here, we determined whether delayed treatment with a GLP-1R agonist could improve metabolic and functional recovery after stroke. Rats were subjected to middle cerebral artery occlusion (MCAO) and given the well-established GLP-1R agonist liraglutide (50, 100, or 200μg/kg) or normal saline (NS) daily for 4 weeks, starting 1 day after MCAO. Cerebral glucose metabolism and neurological deficits were evaluated using (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) imaging and modified neurological severity score (mNSS) test. Levels of neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP), von Willebrand factor (vWF), and GLP-1R were assessed by immunohistochemical staining and Western blot analysis. PET imaging showed that animals treated with liraglutide had significantly higher (18)F-FDG accumulation in the cerebral infarction compared with animals treated with NS. Liraglutide significantly reduced the mNSS score. It also greatly increased the expression of NeuN, GFAP, vWF, and GLP-1R in the cerebral ischemic area at postoperative week 4. These results demonstrated metabolic and functional recovery after delayed treatment with liraglutide in a rat model of cerebral ischemia.

  1. Delayed effect of Kinesio Taping on neuromuscular performance, balance, and lower limb function in healthy individuals: a randomized controlled trial

    PubMed Central

    Lins, Caio A. A.; Borges, Daniel T.; Macedo, Liane B.; Costa, Karinna S. A.; Brasileiro, Jamilson S.

    2016-01-01

    ABSTRACT Background Kinesio Taping (KT) is an elastic bandage that aims to improve neuromuscular performance, although there is no consensus as to its benefits. Objective To analyze the immediate and delayed effects of KT on the neuromuscular performance of the femoral quadriceps, on balance, and lower limb function in healthy subjects. Method This is a randomized controlled trial. Thirty-six women with a mean age of 22.2±3.6 years and BMI of 22.5±2.3 Kg/m2 were divided into three groups: control, with ten minutes of rest (control, n=12), application of Kinesio Taping without tension (placebo, n=12) and with tension (KT, n=12) on the quadriceps. The primary outcome was isokinetic performance, while secondary outcomes were the single-hop test, one-footed static balance, and electromyographic activity. The evaluations were carried out in five stages: 1) before application of KT, 2) immediately after the application of KT, 3) after 24h, 4) after 48h, and 5) after 72h. Mixed ANOVA was used to determine differences between groups. Results There was no change in one-footed static balance, electromyographic activity of the VL in the lower limb function, nor in isokinetic performance between groups. Conclusion KT promotes neither immediate nor delayed changes in neuromuscular performance of the femoral quadriceps in healthy women. PMID:27437714

  2. Determinants of functional performance in long-term survivors of allogeneic hematopoietic stem cell transplantation with chronic graft-versus-host disease (cGVHD)

    PubMed Central

    Mitchell, SA; Leidy, N Kline; Mooney, KH; Dudley, WN; Beck, SL; LaStayo, PC; Cowen, EW; Palit, P; Comis, LE; Krumlauf, MC; Avila, DN; Atlam, N; Fowler, DH; Pavletic, SZ

    2009-01-01

    This study examined factors accounting for functional performance limitations in 100 long-term survivors of allogeneic hematopoietic stem cell transplantation with chronic graft-versus-host disease (cGVHD). Functional performance, measured by the SF-36 physical component summary score, was substantially lower (mean = 36.8±10.7) than the US population norm of 50 (P<0.001). The most severe decrements were in physical function (mean = 38.8±10.9) and physical role function (mean = 37.88±11.88); 68% of respondents exceeded the five-point threshold of minimum clinically important difference below the norm on these subscales. Controlling for age and gender, six variables explained 56% of the variance in functional performance: time since cGVHD diagnosis, cGVHD severity, intensity of immunosuppression, comorbidity, functional capacity (distance walked in 2 min, grip strength, and range of motion), and cGVHD symptom bother (F = 11.26; P<0.001). Significant independent predictors of impaired performance were intensive systemic immunosuppression, reduced capacity for ambulation, and greater cGVHD symptom bother (P<0.05). Symptom bother had a direct effect on functional performance, as well as an indirect effect partially mediated by functional capacity (Sobel test, P = 0.004). Results suggest two possible mechanisms underlying impaired functional performance in survivors with cGVHD and underscore the importance of testing interventions to enhance functional capacity and reduce symptom bother. PMID:19784078

  3. Grafting of Polyaniline onto the Surface of 4-Aminobenzoyl-Functionalized Multiwalled Carbon Nanotube and Its Electrochemical Properties

    DTIC Science & Technology

    2010-01-01

    Fig. 1(c)]. The resultant composite, PANi-grafted MWNT (PANi-g-MWNT), was prepared and it was expected to show improved solution and solid - state ...coating of PANi suppressed the MWNT influence at excited state . If MWNT and PANi were physically aggregated by intermolecu- lar p–p interaction in solid ...Trung, T. H.; Ha, C. S. Electro- chim Acta 2005, 51, 984–990. 31 Perloff, D. S. Solid State Electron 1977, 20, 681–687. 32 Wu, T. M.; Lin, Y. W.; Liao

  4. Esthetic and functional reconstruction of the posttumoral interrupted mandible with double-barrel fibular free flap graft: rationale for a microsurgical and prosthodontic approach.

    PubMed

    Paranque, Armand-Régis; Steve, Marc; Vazquez, Lydia; Bolleyn, Alain; Roze-Pellat, Marie-Andrée; Dohan Ehrenfest, David M

    2011-10-01

    Reconstruction after substantial osseous, cutaneous, and muscular tissue loss following a mandibular resection is a challenge. The use of a fibular free flap is an outstanding, but delicate, treatment option. These grafts, using the double-barrel technique, can achieve an almost complete reconstruction of the mandibular defect. The challenge posed by these treatments is to achieve an end result that is both functional and esthetically pleasing-an endeavor that requires a defined prosthetic plan prior to complete microsurgical reconstruction. Using a detailed clinical case, this article discusses the importance of planning the mandible reconstruction with double-barrel fibular graft in view of an implant-supported fixed partial denture. Immediate implant loading was even possible in this case. This approach allows improvement of the final esthetic and functional result of such a complex rehabilitation. Maxillofacial reconstructive surgery should seek to establish a near-as-normal anatomic situation that will allow a permanent implant rehabilitation that is both esthetic and durable.

  5. [Kidney grafts from elderly donors].

    PubMed

    Hiesse, Christian; Pessione, Fabienne; Cohen, Sophie

    2003-06-07

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

  6. Mutations that permit residual CFTR function delay acquisition of multiple respiratory pathogens in CF patients

    PubMed Central

    2010-01-01

    Background Lung infection by various organisms is a characteristic feature of cystic fibrosis (CF). CFTR genotype effects acquisition of Pseudomonas aeruginosa (Pa), however the effect on acquisition of other infectious organisms that frequently precede Pa is relatively unknown. Understanding the role of CFTR in the acquisition of organisms first detected in patients may help guide symptomatic and molecular-based treatment for CF. Methods Lung infection, defined as a single positive respiratory tract culture, was assessed for 13 organisms in 1,381 individuals with CF. Subjects were divided by predicted CFTR function: 'Residual': carrying at least one partial function CFTR mutation (class IV or V) and 'Minimal' those who do not carry a partial function mutation. Kaplan-Meier estimates were created to assess CFTR effect on age of acquisition for each organism. Cox proportional hazard models were performed to control for possible cofactors. A separate Cox regression was used to determine whether defining infection with Pa, mucoid Pa or Aspergillus (Asp) using alternative criteria affected the results. The influence of severity of lung disease at the time of acquisition was evaluated using stratified Cox regression methods by lung disease categories. Results Subjects with 'Minimal' CFTR function had a higher hazard than patients with 'Residual' function for acquisition of 9 of 13 organisms studied (HR ranging from 1.7 to 3.78 based on the organism studied). Subjects with minimal CFTR function acquired infection at a younger age than those with residual function for 12 of 13 organisms (p-values ranging: < 0.001 to 0.017). Minimal CFTR function also associated with younger age of infection when 3 alternative definitions of infection with Pa, mucoid Pa or Asp were employed. Risk of infection is correlated with CFTR function for 8 of 9 organisms in patients with good lung function (>90%ile) but only 1 of 9 organisms in those with poorer lung function (<50%ile). Conclusions

  7. Sphingolipids are required for mammalian epidermal barrier function. Inhibition of sphingolipid synthesis delays barrier recovery after acute perturbation.

    PubMed Central

    Holleran, W M; Man, M Q; Gao, W N; Menon, G K; Elias, P M; Feingold, K R

    1991-01-01

    Stratum corneum lipids comprise an approximately equimolar mixture of sphingolipids, cholesterol, and free fatty acids, arranged as intercellular membrane bilayers that are presumed to mediate the epidermal permeability barrier. Prior studies have shown that alterations in epidermal barrier function lead to a rapid increase in cholesterol and fatty acid synthesis which parallels the early stages of the repair process. Despite an abundance of indirect evidence for their role in the barrier, the importance of sphingolipids has yet to be demonstrated directly. Whereas sphingolipid synthesis also increases during barrier repair, this response is delayed in comparison to cholesterol and fatty acid synthesis (Holleran, W.M., et al. 1991. J. Lipid Res. 32:1151-1158). To further delineate the role of sphingolipids in barrier homeostasis, we assessed the impact of inhibition of sphingolipid synthesis on epidermal barrier recovery. A single topical application of beta-chloro-L-alanine (beta-CA), an irreversible inhibitor of serine-palmitoyl transferase (SPT), applied to acetone-treated skin of hairless mice resulted in: (a) greater than 75% inhibition of SPT activity at 30 min (P less than 0.001); (b) a global decrease in sphingolipid synthesis between 1 and 3 h (P less than 0.02); (c) reduction of epidermal sphingolipid content at 18 h (P less than 0.01); (d) delayed reaccumulation of histochemical staining for sphingolipids in the stratum corneum; and (e) reduced numbers and contents of lamellar bodies in the stratum granulosum. Finally, despite its immediate, marked diminution of sphingolipid synthesis, beta-CA slowed barrier recovery only at late time points (greater than 6 h) after acetone treatment. This inhibition was overridden by coapplications of ceramides (the distal SPT product), indicating that the delay in repair was not due to non-specific toxicity. These studies demonstrate a distinctive role for epidermal sphingolipids in permeability barrier homeostasis

  8. Delayed ejaculation

    MedlinePlus

    Ejaculatory incompetence; Sex - delayed ejaculation; Retarded ejaculation; Anejaculation; Infertility - delayed ejaculation ... include: Religious background that makes the person view sex as sinful Lack of attraction for a partner ...

  9. Robust and cost effective expansion of human regulatory T cells highly functional in a xenograft model of graft-versus-host disease.

    PubMed

    Chakraborty, Rikhia; Mahendravada, Aruna; Perna, Serena K; Rooney, Cliona M; Heslop, Helen E; Vera, Juan F; Savoldo, Barbara; Dotti, Gianpietro

    2013-04-01

    The low frequency of naturally occurring regulatory T cells (nTregs) in peripheral blood and the suboptimal protocols available for their ex vivo expansion limit the development of clinical trials based on the adoptive transfer of these cells. We have, therefore, generated a simplified, robust and cost-effective platform for the large-scale expansion of nTregs using a gas permeable static culture flask (G-Rex) in compliance with Good Manufacturing Practice. More than 10(9) putative Tregs co-expressing CD25 and CD4 molecules (92 ± 5%) and FoxP3 (69 ± 19%) were obtained within 21 days of culture. Expanded Tregs showed potent regulatory activity in vitro (80 ± 13% inhibition of CD8(+) cell division) and in vivo (suppression or delay of graft-versus-host disease in a xenograft mouse model) indicating that the cost-effective and simplified production of nTregs we propose will facilitate the implementation of clinical trials based on their adoptive transfer.

  10. Delayed closure of the hard palate: a comparison of speech in children with open and functionally closed residual clefts.

    PubMed

    Lohmander-Agerskov, A; Friede, H; Lilja, J; Söderpalm, E

    1996-06-01

    The speech of 20 children with cleft in the hard palate that had not yet been repaired was evaluated and analysed at 7 years of age. The cleft in the hard palate was open in 14 patients and functionally closed in six. All children were born with cleft lip and palate and treated surgically according to a routine that included delayed closure of the hard palate until age 8-10 years. The soft palate was repaired at approximately 6-8 months of age. Tape recordings were used for perceptual analysis of the speech. Maxillary casts were used to assess approximate age for functional closure of the residual cleft. Speech results showed only mild hypernasality for both groups of subjects which indicates acceptable velopharyngeal function in the whole group. Children with open residual clefts had significantly more nasal escape and a higher prevalence of compensatory retracted articulation than children with functionally closed clefts. The functional closure seems to have occurred at about the age of 18-36 months. Factors which appear to facilitate narrowing of the residual cleft include the original width of the cleft, the amount of tissue in the alveolar and palatal processes, and anterior placement of a vomer flap.

  11. Surface functionalization of graphene oxide with poly(2-hydroxyethyl methacrylate)- graft-poly(ɛ-caprolactone) and its electrospun nanofibers with gelatin

    NASA Astrophysics Data System (ADS)

    Massoumi, Bakhshali; Ghandomi, Fereshteh; Abbasian, Mojtaba; Eskandani, Morteza; Jaymand, Mehdi

    2016-12-01

    This article describes covalent functionalization of graphene oxide (GO) with poly(2-hydroxyethyl methacrylate)- graft-poly(ɛ-caprolactone) [P(HEMA- g-CL)] via `living' polymerization techniques and preparation of its electrospun nanofibers with gelatin. For this purpose, the GO was synthesized by oxidizing pristine graphite powder and then acetyl chloride was incorporated into the GO to afford an atom transfer radical polymerization (ATRP) macroinitiator (GO-Cl). The synthesized macroinitiator was employed for HEMA polymerization via ATRP technique to produce GO- g-PHEMA. Afterward, CL was graft copolymerized from the hydroxyl groups of the PHEMA via ring-opening polymerization approach to afford GO- g-[P(HEMA- g-CL)] nanocomposite. The solutions of the GO- g-[P(HEMA- g-CL)] and gelatin were electrospun to fabricate uniform, conductive, and biocompatible nanofibers. The morphology, in vitro degradability, biocompatibility, hydrophilicity, and conductivity of the GO- g-[P(HEMA- g-CL)]/gelatin electrospun nanofibers were investigated. It is expected that the prepared nanofibers find application as a scaffolding biomaterial for regenerative medicine, mainly due to their biocompatibility, degradability, and electrical conductivity.

  12. [Comparison of cross face nerve graft with masseteric nerve as donor nerves for free functional muscle transfers in facial reanimation surgery].

    PubMed

    Eisenhardt, S U; Thiele, J R; Stark, G B; Bannasch, H

    2013-08-01

    Several surgical techniques have been proposed for the reconstruction of the smile in facial paralysis. The 2-stage approach utilising a cross-facial nerve graft (CFNG) and subsequent free functional muscle transfer represents the "gold standard". A single-stage alternative is the use of the masseteric nerve as donor nerve. Here we have retrospectively analysed the outcome of 8 patients who were treated with either of these procedures (4 per treatment group). We compared the oral commisure excursion between the 2 groups. Use of the masseteric nerve led to reinnervation of the muscle graft within 3 months. The 2-stage procedure required more than 12 months from the first procedure until first muscle contractions could be observed. A spontaneous smile could not be achieved in all patients when the masseteric nerve was used. The oral commisure excursion was symmetrical when compared to the healthy side in both groups, however the excursion was significantly higher in the masseteric nerve group compared to the CFNG group of patients. Most patients with the masseteric nerve as a donor nerve underwent a secondary procedure, which involved thinning of the muscle flap. In conclusion, the use of the masseteric nerve as a donor nerve for facial reanimation surgery is a single-stage alternative to the use of a CFNG as donor nerve. It delivers reliable results with strong muscle contractions with limitations in regard to achieving a spontaneous smile.

  13. Environmentally Benign Pyrotechnic Delays

    DTIC Science & Technology

    2012-06-01

    jay.poret@us.army.mil † School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA ABSTRACT Pyrotechnic delays are used in...benign formulations are described. The delay time of the new system is easily tunable. These compositions will consistently function in aluminum ...tunable. These compositions will consistently function in aluminum housings which is generally difficult for delay compositions due to extreme thermal

  14. Effects of Delayed Enteral Nutrition on Inflammatory Responses and Immune Function Competence in Critically Ill Patients with Prolonged Fasting.

    PubMed

    Xi, Fengchan; Li, Ning; Geng, Yanxia; Gao, Tao; Zhang, Juanjuan; Jun, Tanshan; Lin, Zhiliang; Li, Weiqin; Zhu, Weiming; Yu, Wenkui; Li, Jieshou

    2014-05-01

    Although different studies suggest that early enteral nutrition (EEN) has benefits in reducing infectious complications, there is no data that addresses whether delayed enteral nutrition (EN) is detrimental and if it may have effects on inflammatory responses and immune function. Forty-five critically ill patients with long fasting were randomly allocated in two groups according to the type of nutritional support. The first group included patients assuming a standard enteral nutrition (EN, n = 22) and the second group assuming a parenteral nutrition (PN, n = 23). The daily nutritional amount was 25 kcal (105 kJ)/kg for all patients. The inflammatory markers white blood cells (WBC), C-reactive protein (CRP), TNF-α, IL-1-β, IL-6, IL-4, IL- 10 and the immune T-lymphocyte sub-populations CD3+, CD4+, CD8+, and HLA-DR+ were evaluated at day 1, and after 2, 3 and 7 days. IL-4, IL-10, CD3+, CD4+, CD8+ and the CD4+/CD8+ ratio were not statistically different between the two groups. WBC and TNF-α in EN patients were higher than those in PN after 3 and 7 days (P < 0.05). CRP and IL-6 levels were higher in EN patients than those assuming a PN after 2 and 3 days (P < 0.05). HLA-DR levels in patients assuming an EN were found higher than those in PN at day 7 (P < 0.05). Delayed EN for critically ill patients with long-term fasting increased systemic inflammatory responses, whereas EN could modify immune function, therefore reducing hospital stay and costs.

  15. Rectal Hyposensitivity Is Associated With a Defecatory Disorder But Not Delayed Colon Transit Time in a Functional Constipation Population.

    PubMed

    Yu, Ting; Qian, Dong; Zheng, Yongping; Jiang, Ya; Wu, Ping; Lin, Lin

    2016-05-01

    The physiological mechanism of functional constipation (FC) includes defecatory disorders and delayed colon transit. About 18% to 68% constipated patients may have rectal hyposensitivity (RH). We performed this study to investigate the association between RH and functional defecatory disorder (FDD) as well as that between RH and delayed colon transit in FC patients.A total of 218 FC patients were enrolled. The constipation severity instrument (CSI) was used to assess constipation symptoms. High-resolution anorectal manometry (HR-ARM), defecography, balloon expulsion tests, and colon transit studies were performed for each patient. RH was defined as 1 or more sensory threshold pressures raised beyond the normal range based on HR-ARM. We investigated the association between RH and constipation symptoms, and the occurrence of FDD and delayed CTT. Ninety FDD patients completed the initial phase of biofeedback treatment (BFT). We investigated the association between RH and the effect of BFT.Totally 122 (56.0%) patients had RH. The total CSI (49.82 ± 1.09 vs 41.25 ± 1.55, P = 0.023) and obstructive defecation subscale scores (23.19 ± 0.69 vs 17.07 ± 0.90, P < 0.001) were significantly higher in RH than in non-RH patients. No significant difference was observed in slow transit symptoms (21.77 ± 0.72 vs 19.90 ± 0.85, P = 0.121) or abdominal pain (6.85 ± 2.61 vs 5.00 ± 1.04, P = 0.380). The frequency of prolonged CTT was not significantly different between RH and non-RH groups (54.1% vs 58.3%, P = 0.403). RH patients rated more occurrence of FDD (72.1% vs 53.1%, P = 0.014) and dysynergic defecation (79.8% vs 50.2%, P = 0.004) than non-RH patients, whereas no differences were seen for inadequate defecatory propulsion (59.2% vs 55.0%, P = 0.589). After BFT, the proportion of "no effect" was significantly higher in the RH group than in the non-RH group (22.4% vs 9.4%, P = 0.010).RH is associated with

  16. Permanent Motor Function Loss by Delayed Treatment of Peroneal Intraneural Ganglion.

    PubMed

    Oshima, Yasushi; Fetto, Joseph F

    2016-11-01

    The low incidence of intraneural ganglion makes it difficult to diagnose and treat before it becomes serious nerve damage. This case describes a 69-year-old female, who suffered from the right drop foot and was diagnosed as a peroneal intraneural ganglion. Resection of the mass relieved the pain; however, motor function was not recovered. Early diagnosis and nerve decompression are essential for the peroneal intraneural ganglion before critical nerve symptoms.

  17. "Small axonless neurons": postnatally generated neocortical interneurons with delayed functional maturation.

    PubMed

    Le Magueresse, Corentin; Alfonso, Julieta; Khodosevich, Konstantin; Arroyo Martín, Angel A; Bark, Christine; Monyer, Hannah

    2011-11-16

    GABAergic interneurons of the mouse cortex are generated embryonically in the ventral telencephalon. Recent evidence, however, indicated that a subset of cortical cells expressing interneuronal markers originate in the neonatal subventricular zone. This has raised interest in the functional development and incorporation of these postnatally generated cells into cortical circuits. Here we demonstrate that these cells integrate in the cortex, and that they constitute two distinct GABAergic interneuronal classes. Whereas one class reflects the tail end of embryonic interneuron genesis, the other class comprises interneurons that are exclusively generated perinatally and postnatally. The latter constitute a novel subclass of interneurons. They are preferentially located in the deeper layers of the olfactory and orbital cortices, exhibit a unique firing pattern and slow functional maturation. Based on their distinct morphology we termed them "small axonless neurons" and indeed, unlike other cortical neurons, they communicate with their neuronal partners via dendrodendritic synapses. Finally, we provide evidence that the number of small axonless neurons is enhanced by odor enrichment, a further indication that they integrate into neural circuits and participate to olfactory processing.

  18. Conservative Pancreas Graft Preservation at the Extreme

    PubMed Central

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

    2016-01-01

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

  19. Fresh or Cryopreserved CD34(+)-Selected Mobilized Peripheral Blood Stem and Progenitor Cells for the Treatment of Poor Graft Function Following Allogeneic Hematopoietic Cell Transplantation.

    PubMed

    Ghobadi, Armin; Fiala, Mark A; Ramsingh, Giridharan; Gao, Feng; Abboud, Camille N; Stockerl-Goldstein, Keith; Uy, Geoffrey L; Grossman, Brenda J; Westervelt, Peter; DiPersio, John F

    2017-03-17

    CD34(+)-selected stem cell boost (SCB) without conditioning have recently been utilized for poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) with promising results. Unfortunately, many patients have been unable to receive the boost infusion as their donors were unwilling or unable to undergo an additional stem cell collection. Therefore, we conducted this study utilizing either fresh or cryopreserved peripheral blood stem cell products to create CD34(+)-selected boost infusions for the treatment of PGF. Additionally, to explore relationship of CD34(+) dose and response we included a cohort of donors mobilized with plerixafor in addition to the standard G-CSF. Twenty six patients with poor graft function were included in this study. Seventeen donor-recipient pairs were enrolled onto the prospective study; Additional 9 patients treated off-protocol were reviewed retrospectively. Three different donor products were used for CD34(+) selection: (1) fresh mobilized product using G-CSF only, (2) fresh mobilized products using G-CSF and plerixafor, and (3) cryopreserved cells mobilized with G-CSF. CD34(+) cell selection was performed using a CliniMACS. The infusion was not preceded by administration of any chemotherapy or conditioning regimen. Primary objective was hematologic response rate and secondary objectives included CD34(+) yields, incidence and severity of acute and chronic GVHD, overall survival (OS), and relapse-free survival (RFS). The median post-selection CD34(+) count per kg of recipient weight was 3.1x10(6), 10.9x10(6), and 1x10(6) for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. The median CD34(+) yields (defined as the number of CD34(+) cells after selection/CD34(+) cells prior to CD34(+) selection) was 69%, 66%, and 28% for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. Following SCB, 16 of the 26 recipients (62%) had a complete response including

  20. Infected aortoiliofemoral grafts: magnetic resonance imaging.

    PubMed

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

    1985-01-01

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

  1. Interventions to delay functional decline in people with dementia: a systematic review of systematic reviews

    PubMed Central

    Laver, Kate; Dyer, Suzanne; Whitehead, Craig; Clemson, Lindy; Crotty, Maria

    2016-01-01

    Objective To summarise existing systematic reviews that assess the effects of non-pharmacological, pharmacological and alternative therapies on activities of daily living (ADL) function in people with dementia. Design Overview of systematic reviews. Methods A systematic search in the Cochrane Database of Systematic Reviews, DARE, Medline, EMBASE and PsycInfo in April 2015. Systematic reviews of randomised controlled trials conducted in people with Alzheimer's disease or dementia measuring the impact on ADL function were included. Methodological quality of the systematic reviews was independently assessed by two authors using the AMSTAR tool. The quality of evidence of the primary studies for each intervention was assessed using GRADE. Results A total of 23 systematic reviews were included in the overview. The quality of the reviews varied; however most (65%) scored 8/11 or more on the AMSTAR tool, indicating high quality. Interventions that were reported to be effective in minimising decline in ADL function were: exercise (6 studies, 289 participants, standardised mean difference (SMD) 0.68, 95% CI 0.08 to 1.27; GRADE: low), dyadic interventions (8 studies, 988 participants, SMD 0.37, 95% CI 0.05 to 0.69; GRADE: low) acetylcholinesterase inhibitors and memantine (12 studies, 4661 participants, donepezil 10 mg SMD 0.18, 95% CI 0.03 to 0.32; GRADE: moderate), selegiline (7 studies, 810 participants, SMD 0.27, 95% CI 0.13 to 0.41; GRADE: low), huperzine A (2 studies, 70 participants, SMD 1.48, 95% CI 0.95 to 2.02; GRADE: very low) and Ginkgo biloba (7 studies, 2530 participants, SMD 0.36, 95% CI 0.28 to 0.44; GRADE: very low). Conclusions Healthcare professionals should ensure that people with dementia are encouraged to exercise and that primary carers are trained and supported to provide safe and effective care for the person with dementia. Acetylcholinesterase inhibitors or memantine should be trialled unless contraindicated. Trial registration number CRD

  2. Residual dizziness after the first BPPV episode: role of otolithic function and of a delayed diagnosis.

    PubMed

    Faralli, Mario; Lapenna, Ruggero; Giommetti, Giorgia; Pellegrino, Cristina; Ricci, Giampietro

    2016-10-01

    Residual dizziness (RD) following the resolution of a benign paroxysmal positional vertigo (BBPV) episode is frequently reported by patients. Possible causes are still under debate in the literature. This study discusses the possible role of otolithic function and of elapsed time from onset of symptoms to diagnosis in the genesis of RD. In total, 116 patients younger than 65 years with their first episode of BPPV and without any other comorbidities were enrolled in the study. Before a bedside examination, subjective visual vertical (SVV) was determined in the case of a history suggestive of BPPV. SVV was tested 1 week later in those patients with BPPV of the posterior semicircular canal, and in whom positioning maneuvers showed resolution of BPPV. At 1 week control, reported RD and Dizziness Handicap Inventory (DHI) were recorded. Diagnosis and treatment of BPPV occurred within 4 days in 43 patients (group A), between 5 and 8 days in 38 patients (group B) and in more than 9 days in 35 patients (group C). Higher values of reported RD and DHI were recorded in group C, while higher values of SVV deviation were recorded in group A with an inverse relationship between SVV and DHI. Initial peripheral vestibular function asymmetry due to BPPV can induce a new central adaptation. This adaptation becomes better established the longer otoconia remain floating in the endolymph. Because of these changes, the brain is unable to quickly readapt to the old pattern after resolution resulting in more persistent RD.

  3. Helios expression and Foxp3 TSDR methylation of IFNy+ and IFNy- Treg from kidney transplant recipients with good long-term graft function

    PubMed Central

    Trojan, Karina; Unterrainer, Christian; Weimer, Rolf; Bulut, Nuray; Morath, Christian; Aly, Mostafa; Zhu, Li; Opelz, Gerhard

    2017-01-01

    Background There is circumstantial evidence that IFNy+ Treg might have clinical relevance in transplantation. IFNy+ Treg express IFNy receptors and are induced by IFNy. In the present study we investigated in kidney transplant recipients with good long-term stable graft function the absolute cell counts of IFNy+ Treg subsets and whether their expression of Foxp3 is stable or transient. Method Helios expression determined by eight-color-fluorescence flow cytometry and methylation status of the Foxp3 Treg specific demethylation region (TSDR) served as indicators for stability of Foxp3 expression. Methylation status was investigated in enriched IFNy+ and IFNy- Treg preparations originating from peripheral blood using high resolution melt analysis. A total of 136 transplant recipients and 52 healthy controls were studied. Results Proportions of IFNy+ Treg were similar in patients and healthy controls (0.05% and 0.04% of all CD4+ lymphocytes; p = n.s.). Patients also had similar absolute counts of IFNy producing Helios+ and Helios- Treg (p = n.s.). Most of the IFNy+ and IFNy- Treg in transplant recipients had a methylated Foxp3 TSDR, however, there was a sizeable proportion of IFNy+ and IFNy- Treg with demethylated Foxp3 TSDR. Male and female patients showed more frequently methylated IFNy+ and IFNy- Treg than male and female controls (all p<0.05). Conclusions Kidney transplant recipients with good long-term stable graft function have similar levels of IFNy+ Treg as healthy controls. IFNy+ and IFNy- Treg subsets in patients consist of cells with stable and cells with transient Foxp3 expression; however, patients showed more frequently methylated IFNy+ and IFNy- Treg than controls. The data show increased levels of Treg subsets with stable as well as transient Foxp3 expression in patients with stable allograft acceptance compared to healthy controls. PMID:28296931

  4. Effect of pituitary graft-induced hyperprolactinemia on adrenal circadian rhythmicity.

    PubMed

    Villanúa, M A; Tresguerres, J A; Esquifino, A I

    1988-01-01

    Prolactin is involved in the regulation of several endocrine functions. In this study, the possible influence of hyperprolactinemia on circadian corticosterone secretion has been investigated. Pituitary grafted male and female rats exhibited increased plasma PRL levels at 1000 when compared to sham-operated controls. This increase was only maintained over the 24 h period in grafted female rats but not in males, thus suggesting a different sex dependent modification of the regulatory mechanisms of prolactin. The corticosterone secretion pattern in sham operated male and female rats was similar to those described earlier but was altered by hyperprolactinemia according to the sex of the animal. There was a significant decrease in the total amount of corticosterone secreted in a 24 h period in grafted males as compared to control animals, whereas no significant differences were observed in grafted female rats as compared to controls. Grafted females showed a 4 h delay in the 24 h secretion rhythm as compared to control animals. These data suggest that pituitary transplant induced hyperprolactinemia, directly or through modifications in catecholamine turnover, is able to modify adrenal rhythmicity.

  5. Sucrose delays senescence and preserves functional compounds in Asparagus officinalis L.

    PubMed

    Park, Me-Hea

    2016-11-11

    The high metabolic rate of harvested asparagus spears (Asparagus officinalis L.) causes rapid deterioration. To extend shelf life, we investigated the effect of sucrose treatment on asparagus during storage. Asparagus spears were treated with 3%, 5%, and 10% sucrose and stored at 2 °C for 20 h. Cellular respiration decreased, but other processes were unaltered by exogenous sucrose. The overall appearance of asparagus treated with 3% sucrose and stored at 2 °C for 18 days was rated as good and excellent, unlike that of untreated spears. Asparagus treated with sucrose maintained firmness for 15 days, while untreated spears lost firmness and showed increased water-soluble pectin content during storage. Carbohydrate levels were also higher in sucrose-treated than in control samples. Transcript levels of cell-wall-related genes, including xyloglucan endotransglycosylase (XET)1, XET2, and peroxidase (prx)1, prx2, and prx3 were upregulated by sucrose. Cyanidin 3-O-rutinoside and rutin levels immediately increased upon addition of sucrose and remained high relative to the control during storage. Thus, sucrose modulates asparagus cell wall components and maintains the functionality of important compounds during storage, thus effectively prolonging shelf life.

  6. 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.

  7. Functional study of dextran-graft-poly((2-dimethyl amino)ethyl methacrylate) gene delivery vector for tumor therapy.

    PubMed

    Li, Wen-Bin; Yuan, Wei; Xu, Fu-Jian; Zhao, Chen; Ma, Jie; Zhan, Qi-Min

    2013-07-01

    The obstacle of gene therapy is the shortage of efficient delivery system. The development of the gene delivery system with high transfection efficiency and low toxicity appears to be crucial. Recently, we reported that the dextran-graft-poly((2-dimethyl amino)ethyl methacrylate) (DPD) can be potentially used as efficient gene vector. Herein, DPD was systematically studied for its potential in tumor gene therapy. DPD was synthesized and characterized by agarose gel electrophoresis, particle size and zeta potential. The particle size and zeta potential of the DPD/enhanced green fluorescent protein (pEGFP-C1) plasmid complexes at various N/P ratios were 130-150 nm and about 40 mV, respectively. The results showed that DPD exhibit a higher transfection effect compared with Lipofectamine 2K (Lipo 2K), a commercialized vector. The possibility of DPD in gene therapy was evaluated using p53, a gene that has been wildly applied in the research of cancer gene therapy. DPD/pEGFP-C1-p53 complex was found to be able to inhibit tumor cell proliferation through cell cycle arrest and apoptosis. Moreover, the tumor growth was found to be restrained when DPD/pEGFP-C1-p53 complex was used in a xenograft MCF7 tumor model in vivo. These observations indicated that DPD/pEGFP-C1-p53 complex may be considered to be an efficient delivery system for tumor gene therapy.

  8. Functions of Exosomes and Microbial Extracellular Vesicles in Allergy and Contact and Delayed-Type Hypersensitivity.

    PubMed

    Nazimek, Katarzyna; Bryniarski, Krzysztof; Askenase, Philip W

    2016-01-01

    Extracellular vesicles, such as exosomes, are newly recognized intercellular conveyors of functional molecular mechanisms. Notably, they transfer RNAs and proteins between different cells that can then participate in the complex pathogenesis of allergic and related hypersensitivity responses and disease mechanisms, as described herein. This review highlights this important new appreciation of the in vivo participation of such extracellular vesicles in the interactions between allergy-mediating cells. We take into account paracrine epigenetic exchanges mediated by surrounding stromal cells and the endocrine receipt of exosomes from distant cells via the circulation. Exosomes are natural ancient nanoparticles of life. They are made by all cells and in some form by all species down to fungi and bacteria, and are present in all fluids. Besides a new focus on their role in the transmission of genetic regulation, exosome transfer of allergens was recently shown to induce allergic inflammation. Importantly, regulatory and tolerogenic exosomes can potently inhibit allergy and hypersensitivity responses, usually acting nonspecifically, but can also proceed in an antigen-specific manner due to the coating of the exosome surface with antibodies. Deep analysis of processes mediated by exosomes should result in the development of early diagnostic biomarkers, as well as allergen-specific, preventive and therapeutic strategies. These will likely significantly diminish the risks of current allergen-specific parenteral desensitization procedures, and of the use of systemic immunosuppressive drugs. Since extracellular vesicles are physiological, they can be fashioned for the specific delivery of therapeutic molecular instructions through easily tolerated, noninvasive routes, such as oral ingestion, nasal administration, and perhaps even inhalation.

  9. Linear functional observers with guaranteed ɛ-convergence for discrete time-delay systems with input/output disturbances

    NASA Astrophysics Data System (ADS)

    Nguyen, M. C.; Trinh, H.; Nam, P. T.

    2016-10-01

    The problem of designing linear functional observers for discrete time-delay systems with unknown-but-bounded disturbances in both the plant and the output is considered for the first time in this paper. A novel approach to design a minimum-order observer is proposed to guarantee that the observer error is ε-convergent, which means that the estimate converges robustly within an ε-bound of the true state. Conditions for the existence of this observer are first derived. Then, by utilising an extended Lyapunov-Krasovskii functional and the free-weighting matrix technique, a sufficient condition for ε-convergence of the observer error system is given. This condition is presented in terms of linear matrix inequalities with two parameters needed to be tuned, so that it can be efficiently solved by incorporating a two-dimensional search method into convex optimisation algorithms to obtain the smallest possible value for ε. Three numerical examples, including the well-known single-link flexible joint robotic system, are given to illustrate the feasibility and effectiveness of our results.

  10. Electrostrictive Graft Elastomers

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

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

    PubMed

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

    2013-12-05

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

  12. Viva Delay.

    PubMed

    Yahaghi, Hossein; Sorooshian, Shahryar; Yahaghi, Javad

    2016-06-28

    The time delay between submission of a thesis and Viva Voce is intolerable for students. This letter tries to draw the readers' attention to the effect of choosing the right examiner, in order to reduce the Viva Voce delay.

  13. Prevalence of abdominal aortic calcifications in older living renal donors and its effect on graft function and histology.

    PubMed

    Wu, En-Haw; Wojciechowski, David; Chandran, Sindhu; Yeh, Benjamin M; Park, Meyeon; Westphalen, Antonio; Wang, Zhen J

    2015-10-01

    We assessed the prevalence of abdominal aortic calcification (AAC) in older living kidney donors and its effect on recipient eGFR and graft histology. A total of 292 consecutive living pairs with donor age ≥50 from 2003 to 2013 were identified (mean age 56; range 50-78; F/M: 1.8). Donor AAC was determined by prenephrectomy unenhanced CT. Recipient eGFR and spot urine protein: creatinine ratios (UPCRs) were recorded. A total of 180 recipients had 6-month protocol biopsies. AAC was present in 40.7% of donors, and they were older (58.6 versus 54.7 years old, P < 0.0001) and more likely to be male (77.6% vs. 37.3%, P = 0.004). There was no significant difference in eGFR or spot UPCR up to 36 months in recipients of allografts from donors with versus without AAC. At 6-month biopsy, there was a higher percentage of allografts with vascular fibrous intimal thickening and arteriolar hyaline thickening from donors with versus without AAC (vascular fibrous intimal thickening: 38.8% vs. 7.1% and arteriolar hyaline thickening: 35.8% vs. 7.1%; P < 0.001 for both). The presence of donor AAC predicts the presence of vascular disease [vascular fibrous intimal thickening (OR: 7.2; CI:2.9-17.9) and arteriolar hyaline thickening (OR:5.7; CI:2.3-14.1)] in allografts at 6 months. Donor AAC is predictive of renal vascular disease and may help to improve the screening of potential donors and inform post-transplant management.

  14. Structural and Functional Aspects of Social Support for Mothers of Children with and without Cognitive Delays in Vietnam

    ERIC Educational Resources Information Center

    Park, So-Youn; Glidden, Laraine M.; Shin, Jin Y.

    2010-01-01

    Background: This study reports development of a social support scale appropriate to the Vietnamese culture and the impact of social support on mothers of children with cognitive delays by using the developing scale. Method: Interview surveys were conducted with 225 mothers of children with and without cognitive delays in Vietnam. The structural…

  15. Glial Restricted Precursor Cell Transplant with Cyclic Adenosine Monophosphate Improved Some Autonomic Functions but Resulted in a Reduced Graft Size after Spinal Cord Contusion Injury in Rats

    PubMed Central

    Nout, Yvette S.; Culp, Esther; Schmidt, Markus H.; Tovar, C. Amy; Pröschel, Christoph; Mayer-Pröschel, Margot; Noble, Mark D.; Beattie, Michael S.; Bresnahan, Jacqueline C.

    2010-01-01

    Transplantation of glial restricted precursor (GRP) cells has been shown to reduce glial scarring after spinal cord injury (SCI) and, in combination with neuronal restricted precursor (NRP) cells or enhanced expression of neurotrophins, to improve recovery of function after SCI. We hypothesized that combining GRP transplants with rolipram and cAMP would improve functional recovery, similar to that seen after combining Schwann cell transplants with increasing cAMP. A short term study, 1)uninjured control, 2)SCI+vehicle, and 3)SCI+cAMP, showed that spinal cord [cAMP] were increased 14 days after SCI. We used 51 male rats subjected to a thoracic SCI for a 12-week survival study: 1)SCI+vehicle, 2)SCI+GRP, 3)SCI+cAMP, 4)SCI+GRP+cAMP, and 5)uninjured endpoint age-matched control (AM). Rolipram was administered for 2 weeks after SCI. At 9 days after SCI, GRP transplantation and injection of dibutyryl-cAMP into the spinal cord were performed. GRP cells survived, differentiated, and formed extensive transplants that were well integrated with host tissue. Presence of GRP cells increased the amount of tissue in the lesion; however, cAMP reduced the graft size. White matter sparing at the lesion epicenter was not affected. Serotonergic input to the lumbosacral spinal cord was not affected by treatment, but the amount of serotonin immediately caudal to the lesion was reduced in the cAMP groups. Using telemetric monitoring of corpus spongiosum penis pressure we show that the cAMP groups regained the same number of micturitions per 24 hrs when compared to the AM group, however, the frequency of peak pressures was increased in these groups compared to the AM group. In contrast, the GRP groups had similar frequency of peak pressures compared to baseline and the AM group. Animals that received GRP cells regained the same number of erectile events per 24 hrs compared to baseline and the AM group. Since cAMP reduced the GRP transplant graft, and some modest positive effects were seen

  16. Glial restricted precursor cell transplant with cyclic adenosine monophosphate improved some autonomic functions but resulted in a reduced graft size after spinal cord contusion injury in rats.

    PubMed

    Nout, Yvette S; Culp, Esther; Schmidt, Markus H; Tovar, C Amy; Pröschel, Christoph; Mayer-Pröschel, Margot; Noble, Mark D; Beattie, Michael S; Bresnahan, Jacqueline C

    2011-01-01

    Transplantation of glial restricted precursor (GRP) cells has been shown to reduce glial scarring after spinal cord injury (SCI) and, in combination with neuronal restricted precursor (NRP) cells or enhanced expression of neurotrophins, to improve recovery of function after SCI. We hypothesized that combining GRP transplants with rolipram and cAMP would improve functional recovery, similar to that seen after combining Schwann cell transplants with increasing cAMP. A short term study, (1) uninjured control, (2) SCI+vehicle, and (3) SCI+cAMP, showed that spinal cord [cAMP] was increased 14days after SCI. We used 51 male rats subjected to a thoracic SCI for a 12-week survival study: (1) SCI+vehicle, (2) SCI+GRP, (3) SCI+cAMP, (4) SCI+GRP+cAMP, and (5) uninjured endpoint age-matched control (AM). Rolipram was administered for 2weeks after SCI. At 9days after SCI, GRP transplantation and injection of dibutyryl-cAMP into the spinal cord were performed. GRP cells survived, differentiated, and formed extensive transplants that were well integrated with host tissue. Presence of GRP cells increased the amount of tissue in the lesion; however, cAMP reduced the graft size. White matter sparing at the lesion epicenter was not affected. Serotonergic input to the lumbosacral spinal cord was not affected by treatment, but the amount of serotonin immediately caudal to the lesion was reduced in the cAMP groups. Using telemetric monitoring of corpus spongiosum penis pressure we show that the cAMP groups regained the same number of micturitions per 24hours when compared to the AM group, however, the frequency of peak pressures was increased in these groups compared to the AM group. In contrast, the GRP groups had similar frequency of peak pressures compared to baseline and the AM group. Animals that received GRP cells regained the same number of erectile events per 24hours compared to baseline and the AM group. Since cAMP reduced the GRP transplant graft, and some modest positive

  17. Surface functionalization of a poly(butylene terephthalate) (PBT) melt-blown filtration membrane by wet chemistry and photo-grafting.

    PubMed

    Salvagnini, Claudio; Roback, Alexandre; Momtaz, Maryam; Pourcelle, Vincent; Marchand-Brynaert, Jacqueline

    2007-01-01

    The surface functionalization of PBT melt-blown membrane, making up a whole filter of blood components, was achieved via two methods. Hydroxyl chain-end activation by tosylation (method A), followed by coupling of F- and (3)H-tagged molecules (probes), led to 1% of surface derivatization (XPS) and 290 pmol/cm(2) of lysine fixation (LSC). Deposition of O-succinimidyl 4-(p-azido-phenyl)butanoate ("molecular clip") and 2 h irradiation at 254 nm led to the implanting of activated ester functions, randomly on the polymer surface (method B). Further coupling of F- and (3)H-probes by wet chemistry gave highly functionalized surface (4% by XPS and 1000 pmol/cm(2) by LSC). However, control experiments showed that about 80% of the surface derivatization resulted from the UV treatment alone. Thus, the effect of UV irradiation on PBT membrane was systematically studied and analyzed by XPS, contact angle measurements, GPC and surface reactivity assays. The optimized conditions of "molecular clip" photo-grafting (negligible polymer photo-oxidation/photo-degradation) led to the covalent fixation of 45 pmol/cm(2) of (3)H-probe. Throughout our study, the behaviour of PBT melt-blown membrane was compared to PBT film and PET track-etched membrane similarly treated. Lastly, the method B was applied to couple GRGDS peptide on the PBT membrane; this material showed improved properties of leukocyte depletion in buffy coat filtration experiments.

  18. Human acellular dermal matrix grafts for rhinoplasty.

    PubMed

    Sherris, David A; Oriel, Brad S

    2011-09-01

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

  19. 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

  20. DELAY OF 2 OR 6 WEEKS ADVERSELY AFFECTS THE FUNCTIONAL OUTCOME OF AUGMENTED PRIMARY REPAIR OF THE PORCINE ANTERIOR CRUCIATE LIGAMENT

    PubMed Central

    Magarian, Elise M.; Fleming, Braden C.; Harrison, Sophia L.; Mastrangelo, Ashley N.; Badger, Gary J.; Murray, Martha M.

    2010-01-01

    BACKGROUND Enhanced primary ACL repair, in which suture repair is performed in conjunction with a collagen-platelet composite to stimulate healing, is a potential new treatment option for ACL injuries. Previous studies have evaluated this approach at the time of ACL disruption. HYPOTHESIS In this study, we hypothesized that delaying surgery by 2 or 6 weeks would have a significant effect on the functional outcome of the repair. STUDY DESIGN Controlled Laboratory Study METHODS Sixteen female Yorkshire pigs underwent staged, bilateral surgical ACL transections. ACL transection was initially performed on one knee and the knee closed. Two or six weeks later, enhanced primary repair was performed in that knee while the contralateral knee had an ACL transection and immediate repair. Biomechanical parameters were measured after 15 weeks in vivo to determine the effect of delay time relative to immediate repair on the healing response. RESULTS Yield load of the repairs at 15 weeks was decreased by 40% and 60% in the groups where repair was delayed for 2 and 6 weeks respectively (p=0.01). Maximum load showed similar results (55% and 60% decrease in the 2 and 6 week delay groups respectively, p=0.011). Linear stiffness also was adversely affected by delay (50% decrease compared to immediate repair after either a 2 or 6 week delay, p=0.011). AP laxity after 15 weeks of healing was 40% higher in knees repaired after a 2 week delay, and 10% higher in those repaired after a six week delay (p=0.012) when tested at 30 degrees of flexion, but was not significantly affected by delay when tested at 60 or 90 degrees (p=0.21). CONCLUSIONS A delay between ACL injury and enhanced primary repair has a significant negative effect on the functional performance of the repair. CLINICAL RELEVANCE As future investigations assess new techniques of ACL repair, the timing of the repair should be considered in the design and the interpretation of experimental studies. PMID:20855556

  1. Autologous Bone Graft in Foot and Ankle Surgery.

    PubMed

    Miller, Christopher P; Chiodo, Christopher P

    2016-12-01

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

  2. Comparison of Obese Adults with Poor versus Good Sleep Quality during a Functional Neuroimaging Delay Discounting Task: A Pilot Study

    PubMed Central

    Martin, Laura E.; Pollack, Lauren; McCune, Ashley; Schulte, Erica; Savage, Cary R.; Lundgren, Jennifer D.

    2015-01-01

    This study aimed to determine if obese adults with poor versus good sleep quality demonstrate reduced self-regulatory capacity and different patterns of neural activation when making impulsive monetary choices. Six obese, good quality sleepers (M age = 44.7 years, M BMI = 83.1 kg/m2) were compared to 13 obese, poor quality sleepers (M age = 42.6, M BMI = 39.2 kg/m2) on sleep and eating behavior and brain activation in prefrontal and insular regions while engaging in a delay discounting task during functional magnetic resonance imaging (fMRI). Poor quality sleepers demonstrated significantly lower brain activation in the right inferior frontal gyrus, right middle frontal gyrus, and bilateral insula when making immediate and smaller (impulsive) monetary choices compared to the baseline condition. Behaviorally, poor compared to good quality sleepers reported higher scores in the night eating questionnaire. Obese adults with poor sleep quality demonstrate decreased brain activation in multiple regions that regulate cognitive control and interceptive awareness, possibly reducing self-regulatory capacity when making immediately gratifying decisions. PMID:26358975

  3. Anterior Cruciate Ligament Graft Choices

    PubMed Central

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

    2012-01-01

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

  4. Graft-versus-host reaction and immune function. IV. B cell functional defect associated with a depletion of splenic colony-forming units in marrow of graft-versus-host-reactive mice

    SciTech Connect

    Seddik, M.; Seemayer, T.A.; Lapp, W.S.

    1986-02-01

    Studies were conducted to determine whether a functional B cell defect occurred in the bone marrow of mice experiencing a GVH reaction (GVHBM). GVH reactions were induced in AxCBA F1 adult mice by an injection of A strain lymphoid cells. The GVH reaction was confirmed by immunosuppression and thymus histology. At various intervals after GVH induction, GVHBM was tested for its ability to restore B cell function in adult thymectomized irradiated mice reconstituted with normal thymocytes. GVHBM cells obtained seven days after GVH induction restored but slightly the plaque forming cell (PFC) response to sheep erythrocytes and the mitogen response to lipopolysaccharide (LPS). GVHBM cells obtained 10 days or later failed to reconstitute the PFC or LPS responses. GVHBM cells suppressed neither the T or B cell function of normal spleen cells nor the LPS mitogen response of normal bone marrow cells. In addition, the splenic colony-forming units (CFU-s) in GVHBM were slightly decreased by day 10 after GVH induction and markedly depressed by day 22 after GVH induction. These results suggest that the GVH reaction may affect two different events in B cell differentiation. The early decrease in functional B cells that occurs before there is any change in the CFU-s population suggests a direct effect on B cell production, whereas the later absence of functional B cells could be due to the marked decline in stem cell production (CFU-s).

  5. Mean-square exponential input-to-state stability of delayed Cohen-Grossberg neural networks with Markovian switching based on vector Lyapunov functions.

    PubMed

    Li, Zhihong; Liu, Lei; Zhu, Quanxin

    2016-12-01

    This paper studies the mean-square exponential input-to-state stability of delayed Cohen-Grossberg neural networks with Markovian switching. By using the vector Lyapunov function and property of M-matrix, two generalized Halanay inequalities are established. By means of the generalized Halanay inequalities, sufficient conditions are also obtained, which can ensure the exponential input-to-state stability of delayed Cohen-Grossberg neural networks with Markovian switching. Two numerical examples are given to illustrate the efficiency of the derived results.

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

    SciTech Connect

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

    1991-06-01

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

  7. Surface functionalization of copper via oxidative graft polymerization of 2,2'-bithiophene and immobilization of silver nanoparticles for combating biocorrosion.

    PubMed

    Wan, Dong; Yuan, Shaojun; Neoh, K G; Kang, E T

    2010-06-01

    An environmentally benign approach to surface modification was developed to impart copper surface with enhanced resistance to corrosion, bacterial adhesion and biocorrosion. Oxidative graft polymerization of 2,2'-bithiophene from the copper surface with self-assembled 2,2'-bithiophene monolayer, and subsequent reduction of silver ions to silver nanoparticles (Ag NPs) on the surface, give rise to a homogeneous bithiophene polymer (PBT) film with densely coupled Ag NPs on the copper surface (Cu-g-PBT-Ag NP surface). The immobilized Ag NPs were found to significantly inhibit bacterial adhesion and enhance the antibacterial properties of the PBT modified copper surface. The corrosion inhibition performance of the functionalized copper substrates was evaluated by Tafel polarization curves and electrochemical impedance spectroscopy. Arising from the chemical affinity of thiols for the noble and coinage metals, the copper surface functionalized with both PBT brushes and Ag NPs also exhibits long-term stability, and is thus potentially useful for combating the combined problems of corrosion and biocorrosion in harsh marine and aquatic environments.

  8. Fine-Tuning of the Carbon Dioxide Capture Capability of Diamine-Grafted Metal-Organic Framework Adsorbents Through Amine Functionalization.

    PubMed

    Jo, Hyuna; Lee, Woo Ram; Kim, Nam Woo; Jung, Hyun; Lim, Kwang Soo; Kim, Jeong Eun; Kang, Dong Won; Lee, Hanyeong; Hiremath, Vishwanath; Seo, Jeong Gil; Jin, Hailian; Moon, Dohyun; Han, Sang Soo; Hong, Chang Seop

    2017-02-08

    A combined sonication and microwave irradiation procedure provides the most effective functionalization of ethylenediamine (en) and branched primary diamines of 1-methylethylenediamine (men) and 1,1-dimethylethylenediamine (den) onto the open metal sites of Mg2 (dobpdc) (1). The CO2 capacities of the advanced adsorbents 1-en and 1-men under simulated flue gas conditions are 19 wt % and 17.4 wt %, respectively, which are the highest values reported among amine-functionalized metal-organic frameworks (MOFs) to date. Moreover, 1-den exhibits both a significant working capacity (12.2 wt %) and superb CO2 uptake (11 wt %) at 3 % CO2 . Additionally, this framework showcases the superior recyclability; ultrahigh stability after exposure to O2 , moisture, and SO2 ; and exceptional CO2 adsorption capacity under humid conditions, which are unprecedented among MOFs. We also elucidate that the performance of CO2 adsorption can be controlled by the structure of the diamine ligands grafted such as the number of amine end groups or the presence of side groups, which provides the first systematic and comprehensive demonstration of fine-tuning of CO2 uptake capability using different amines.

  9. Design of a surface-immobilized 4-nitrophenol molecularly imprinted polymer via pre-grafting amino functional materials on magnetic nanoparticles.

    PubMed

    Mehdinia, Ali; Dadkhah, Sahar; Baradaran Kayyal, Tohid; Jabbari, Ali

    2014-10-17

    In order to resolve the low adsorption capacity of the surface molecularly imprinting methods, an approach was developed for the preparation of magnetic imprinted polymers by pre-grafting the amino functional material, 3-aminopropyltriethoxysilane (APTES), on the surface of the silica coated magnetic substrate. APTES was used for amino functionalization of the silica coated Fe3O4 nanoparticles. Amino groups were used for immobilization of the template molecules on the magnetic surface and additionally to react with the terminal vinyl groups of cross-linker, ethylene glycol dimethacrylate (EGDMA), by the Michael addition reaction. In this way, the imprinting sites of the analytes formed on the substrate were increased. The sorbent was synthesized in the presence of 4-nitrophenol (4-NP) and EGDMA as the template and cross-linker, respectively. Different parameters affecting the adsorption, such as pH, desorption solvent type and adsorption time were evaluated and optimized. The prepared magnetic molecularly imprinted polymer (MMIP) showed high adsorption capacity and proper selectivity for the template molecule. The kinetic adsorption curve indicated that 90 min was sufficient to achieve the adsorption equilibrium for MMIP. The maximum adsorption capacity was 129.1 mg g(-1). The experiments exhibited a linear range of 10-3000 μg L(-1) for 4-NP with the correlation coefficient (R(2)) of 0.997. The results of the real sample analysis confirmed the applicability of the proposed MMIP for quantitative analysis of 4-NP in the aqueous samples.

  10. The Role of E-Cadherin in Maintaining the Barrier Function of Corneal Epithelium after Treatment with Cultured Autologous Oral Mucosa Epithelial Cell Sheet Grafts for Limbal Stem Deficiency

    PubMed Central

    Hoft, Richard H.; Wood, Andrew; Oliva, Joan; Niihara, Hope; Makalinao, Andrew; Thropay, Jacquelyn; Pan, Derek; Tiger, Kumar; Garcia, Julio; Laporte, Amanda; French, Samuel W.; Niihara, Yutaka

    2016-01-01

    The role of E-cadherin in epithelial barrier function of cultured autologous oral mucosa epithelial cell sheet (CAOMECS) grafts was examined. CAOMECS were cultured on a temperature-responsive surface and grafted onto rabbit corneas with Limbal Stem Cell Deficiency (LSCD). E-cadherin levels were significantly higher in CAOMECS compared to normal and LSCD epithelium. Beta-catenin colocalized with E-cadherin in CAOMECS cell membranes while phosphorylated beta-catenin was significantly increased. ZO-1, occludin, and Cnx43 were also strongly expressed in CAOMECS. E-cadherin and beta-catenin localization at the cell membrane was reduced in LSCD corneas, while CAOMECS-grafted corneas showed a restoration of E-cadherin and beta-catenin expression. LSCD corneas did not show continuous staining for ZO-1 or for Cnx43, while CAOMECS-grafted corneas showed a positive expression of ZO-1 and Cnx43. Cascade Blue® hydrazide did not pass through CAOMECS. Because E-cadherin interactions are calcium-dependent, EGTA was used to chelate calcium and disrupt cell adhesion. EGTA-treated CAOMECS completely detached from cell culture surface, and E-cadherin levels were significantly decreased. In conclusion, E cadherin high expression contributed to CAOMECS tight and gap junction protein recruitment at the cell membrane, thus promoting cellular adhesion and a functional barrier to protect the ocular surface. PMID:27777792

  11. Delayed recovery of right ventricular systolic function after repair of long-standing tricuspid regurgitation associated with severe right ventricular failure.

    PubMed

    Kim, Jong Hun; Kim, Kyung Hwa; Choi, Jong Bum; Kuh, Ja Hong

    2016-03-01

    After tricuspid valve surgery for long-standing tricuspid regurgitation associated with right ventricular failure, reverse remodelling of the enlarged right ventricle, including recovery of right ventricular systolic function, is unpredictable. We present the case of a 31-year old man with early reduction of dilated right ventricular dimensions and delayed recovery of impaired right ventricular systolic function after valve repair for traumatic tricuspid regurgitation lasting 16 years.

  12. 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.

  13. Nanocomposite Prepared from In Situ Grafting of Polypyrrole to Aminobenzoyl-Functionalized Multiwalled Carbon Nanotube and Its Electrochemical Properties

    DTIC Science & Technology

    2011-01-01

    the functionalization of multiwalled car- bon nanotube (MWCNT) with 4-aminobenzoic acid by a ‘‘direct’’ Friedel – Crafts acylation reaction in a mild...functionalization of multiwalled carbon nanotube (MWCNT) with 4-aminobenzoic acid by a ??direct?? Friedel ? Crafts acylation reaction in a mild polyphosphoric...chemical modification of various CNMs by ‘‘direct’’ Friedel – Crafts acylation reaction in a mild polyphosphoric acid (PPA)/ phosphorous pentoxide (P2O5

  14. Reconsidering the importance of the past in predator-prey models: both numerical and functional responses depend on delayed prey densities.

    PubMed

    Li, Jiqiu; Fenton, Andy; Kettley, Lee; Roberts, Phillip; Montagnes, David J S

    2013-10-07

    We propose that delayed predator-prey models may provide superficially acceptable predictions for spurious reasons. Through experimentation and modelling, we offer a new approach: using a model experimental predator-prey system (the ciliates Didinium and Paramecium), we determine the influence of past-prey abundance at a fixed delay (approx. one generation) on both functional and numerical responses (i.e. the influence of present : past-prey abundance on ingestion and growth, respectively). We reveal a nonlinear influence of past-prey abundance on both responses, with the two responding differently. Including these responses in a model indicated that delay in the numerical response drives population oscillations, supporting the accepted (but untested) notion that reproduction, not feeding, is highly dependent on the past. We next indicate how delays impact short- and long-term population dynamics. Critically, we show that although superficially the standard (parsimonious) approach to modelling can reasonably fit independently obtained time-series data, it does so by relying on biologically unrealistic parameter values. By contrast, including our fully parametrized delayed density dependence provides a better fit, offering insights into underlying mechanisms. We therefore present a new approach to explore time-series data and a revised framework for further theoretical studies.

  15. 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).

  16. Functional significance of parasitism-induced suppression of juvenile hormone esterase activity in developmentally delayed Choristoneura fumiferana larvae.

    PubMed

    Cusson, M; Laforge, M; Miller, D; Cloutier, C; Stoltz, D

    2000-03-01

    The parasitic wasp Tranosema rostrale transmits a polydnavirus (PDV) to its host, Choristoneura fumiferana, during oviposition. Last-instar C. fumiferana larvae parasitized by T. rostrale early in the stadium fail to undergo metamorphosis, and injection of the wasp's calyx fluid (CxF; contains PDV) into healthy caterpillars induces a dose-dependent delay in initiation of metamorphosis (D. Doucet and M. Cusson, 1996, Entomol. Exp. Appl. 81, 21-30). In the present work, parasitization and injection of CxF (0.5 female equivalent) on the first day of the last stadium both prevented the rise in hemolymph 20-hydroxyecdysone (20HE) titer observed between day 4 and day 7 in control and saline-injected larvae. Similarly, juvenile hormone esterase (JHE) activity was depressed following parasitization or CxF injection, whereas control larvae displayed a peak on day 4. However, neither parasitism nor injection of CxF on day 1 prevented the JH-producing glands from turning off during the first half of the last stadium. Likewise, low but clearly detectable JH titers were observed in the first hours following the molt but very low titers, at or near the detection limit of our radioimmunoassay, were seen in both control and parasitized larvae on day 4. Prothoracic glands showed no apparent sign of degeneration 4 days after injection of CxF but had significantly smaller cells than saline-injected larvae 7 days postinjection. It is not clear whether this was a direct effect of T. rostrale PDV. Thus, disruption of spruce budworm metamorphosis by T. rostrale CxF involves depression of 20HE titers but is not associated with a measurable increase in the level of JH, as shown for some other host-parasitoid systems. In view of the latter observation, we put forward three hypotheses regarding the functional significance of the observed suppression of JHE activity in developmentally arrested C. fumiferana larvae.

  17. Continuous ACL graft, results

    PubMed Central

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

    2017-01-01

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

  18. Polypeptide Grafted Hyaluronan: Synthesis and Characterization

    PubMed Central

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

    2010-01-01

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

  19. Mitral valve repair is not always needed in patients with functional mitral regurgitation undergoing coronary artery bypass grafting and/or aortic valve replacement

    PubMed Central

    Lindeboom, J.E.; Jaarsma, W.; Kelder, J.C.; Morshuis, W.J.; Visser, C.A.

    2005-01-01

    Background and aim Functional mitral regurgitation (FMR) is defined as mitral regurgitation in the absence of intrinsic valvular abnormalities. We prospectively evaluated the effect of coronary artery bypass grafting (CABG) and/or aortic valve replacement (AVR), without additional mitral valve repair, on the degree of moderate or severe FMR. Study design and methods From a cohort of 2829 patients undergoing CABG and/or AVR in the St. Antonius Hospital, 67 patients were identified with moderate or severe FMR by transthoracic and transoesophageal Doppler echocardiography. Results Two out of the 67 patients (3%) died perioperatively. During follow-up (3-18 months) mitral regurgitation decreased by one grade in 29 patients, by two grades in 28, by three grades in five patients and remained unchanged in one patient (p=0.0001). Of all patients, 85% had grade I mitral regurgitation or less. Grade II mitral regurgitation remained in nine patients with a previous large myocardial infarction and/or annular calcifications. NYHA class improved from 3.1+0.5 to 1.4+0.4 (p=0.0001). Ejection fraction increased from 46 to 55% (p=0.0001). Overall, left atrial and left ventricular end-diastolic dimensions decreased significantly. In contrast, no decrease in dimensions was seen in patients with postoperative grade II mitral regurgitation. Conclusion FMR may improve significantly following CABG and/or AVR, although a previous large myocardial infarction and/or annular calcifications may affect outcome. PMID:25696484

  20. The bone marrow microenvironment is similarly impaired in allogeneic hematopoietic stem cell transplantation patients with early and late poor graft function.

    PubMed

    Kong, Y; Wang, Y-T; Hu, Y; Han, W; Chang, Y-J; Zhang, X-H; Jiang, Z-F; Huang, X-J

    2016-02-01

    Poor graft function (PGF), including early and late PGF, is a serious complication following allotransplant. We recently reported that bone marrow microenvironment abnormalities may occur in cases of late PGF. Whether these abnormalities occur in early PGF remains unknown. To answer this question, we performed a nested case-control study comparing cellular elements of the bone marrow microenvironment in 10 subjects with early PGF, 30 subjects with late PGF and 40 subjects without PGF. Bone marrow endosteal cells, perivascular cells and endothelial cells were analyzed by flow cytometry and by hematoxylin-eosin and immunohistochemical staining in situ. Subjects with early and late PGF had similar abnormalities in these cell types compared with transplant recipients without PGF. However, none of the aforementioned elements of the bone marrow microenvironment were significantly different between early and late PGF patients. Our data suggest that similar abnormalities in the bone marrow microenvironment may occur in early and late PGF post allotransplant. Cellular approaches, such as the administration of mesenchymal stem cells, promise to be beneficial therapeutic strategies in patients with early or late PGF.

  1. Algisyl-LVR™ with coronary artery bypass grafting reduces left ventricular wall stress and improves function in the failing human heart☆,☆☆

    PubMed Central

    Lee, Lik Chuan; Wall, Samuel T.; Klepach, Doron; Ge, Liang; Zhang, Zhihong; Lee, Randall J.; Hinson, Andy; Gorman, Joseph H.; Gorman, Robert C.; Guccione, Julius M.

    2013-01-01

    Background Left ventricular (LV) wall stress reduction is a cornerstone in treating heart failure. Large animal models and computer simulations indicate that adding non-contractile material to the damaged LV wall can potentially reduce myofiber stress. We sought to quantify the effects of a novel implantable hydrogel (Algisyl-LVR™) treatment in combination with coronary artery bypass grafting (i.e. Algisyl-LVR™+CABG) on both LV function and wall stress in heart failure patients. Methods and results Magnetic resonance images obtained before treatment (n=3), and at 3 months (n=3) and 6 months (n=2) afterwards were used to reconstruct the LV geometry. Cardiac function was quantified using end-diastolic volume (EDV), end-systolic volume (ESV), regional wall thickness, sphericity index and regional myofiber stress computed using validated mathematical modeling. The LV became more ellipsoidal after treatment, and both EDV and ESV decreased substantially 3 months after treatment in all patients; EDV decreased from 264±91 ml to 146±86 ml and ESV decreased from 184±85 ml to 86±76 ml. Ejection fraction increased from 32±8% to 47±18% during that period. Volumetric-averaged wall thickness increased in all patients, from 1.06±0.21 cm (baseline) to 1.3±0.26 cm (3 months). These changes were accompanied by about a 35% decrease in myofiber stress at end-of-diastole and at end-of-systole. Post-treatment myofiber stress became more uniform in the LV. Conclusions These results support the novel concept that Algisyl-LVR™+CABG treatment leads to decreased myofiber stress, restored LV geometry and improved function. PMID:23394895

  2. Serial discrimination reversal learning in pigeons as a function of signal properties during the delay of reinforcement.

    PubMed

    Ploog, Bertram O; Williams, Ben A

    2013-09-01

    Pigeons learned a series of reversals of a simultaneous red-green discrimination with a 6-s delay of reinforcement. The signal properties during the 6-s reinforcement delay were varied across blocks of reversals, such that the delay was either unsignaled (intertrial interval conditions during the delay) or signaled by illumination of the center key. Four different signal conditions were presented: (1) signals only after S+ responses, (2) signals only after S- responses, (3) differential signals after S+ versus S- responding, and (4) the same nondifferential signals after S+ and S- responses. (A zero-delay control condition was also included.) Learning was at a high level in the S+ -only and differential-signal conditions, and learning was at a low level during the unsignaled, nondifferentially signaled, and S- signal conditions. Thus, a differential stimulus contingent on correct choices was necessary for proficient learning-to-learn, even though within-reversal learning occurred in all conditions. During the S+ and differential-signal conditions, improvement in learning continued to occur even after more than 240 reversals (more than 38,000 trials).

  3. Pentafluorophenyl ester-functionalized phosphorylcholine polymers: preparation of linear, two-arm, and grafted polymer-protein conjugates.

    PubMed

    McRae, Samantha; Chen, Xiangji; Kratz, Katrina; Samanta, Debasis; Henchey, Elizabeth; Schneider, Sallie; Emrick, Todd

    2012-07-09

    Novel pentafluorophenyl (PFP)-ester-functionalized phosphorylcholine (PC) polymers of different architectures were prepared and conjugated to lysozyme as a model protein. Linear and two-arm poly(2-methacryloyloxyethyl phosphorylcholine) (polyMPC) structures containing PFP functionality at the chain-end were prepared by atom transfer radical polymerization (ATRP) from novel initiators. Additional conjugates were prepared from phosphorylcholine-substituted cyclooctene (PC-COE) polymers containing PFP-ester bearing comonomers. The polymer-protein conjugates were characterized by HPLC, FPLC, and DLS and were seen to retain most (~80% or greater) of their native enzymatic activity. Pharmacokinetic profiles of the polymer-protein conjugates were studied in mice and found to increase the circulation half-life compared with lysozyme alone.

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

    PubMed

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

    2010-02-09

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

  5. Diagnosis of arterial prosthetic graft infection by /sup 111/In oxine white blood cell scans

    SciTech Connect

    McKeown, P.P.; Miller, D.C.; Jamieson, S.W.; Mitchell, R.S.; Reitz, B.A.; Olcott, C.; Mehigan, J.T.; Silberstein, R.J.; McDougall, I.R.

    1982-08-01

    Early and accurate diagnosis of infected prosthetic arterial grafts is difficult, despite the application of diverse diagnostic modalities. Delay in making the diagnosis is largely responsible for the high amputation and mortality rates associated with this complication. In nine patients with suspected graft infections, /sup 111/In white blood cell scanning was useful and accurate. Graft infection was proved in five cases and ruled out in three. One false-positive scan was due to a sigmoid diverticular abscess overlying the graft. /sup 111/In white blood cell scans may improve the accuracy of diagnosing infected prosthetic grafts, which may result in better limb and patient salvage rates.

  6. Digital time delay

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

  7. Effectively Improving Extinction Coefficient of Benzodithiophene and Benzodithiophenedione-based Photovoltaic Polymer by Grafting Alkylthio Functional Groups.

    PubMed

    Wang, Qi; Zhang, Shaoqing; Xu, Bowei; Ye, Long; Yao, Huifeng; Cui, Yong; Zhang, Hao; Yuan, Wenxia; Hou, Jianhui

    2016-10-06

    Alkylthio groups have received much attention in the polymer community for their molecular design applications in polymer solar cells. In this work, alkylthio substitution on the conjugated thiophene side chains in benzodithiophene (BDT) and benzodithiophenedione (BDD)-based photovoltaic polymer was used to improve the extinction coefficient. The introduction of alkylthio groups into the polymer increased its extinction coefficient while the HOMO levels, bandgaps, and absorption bands remained the same. Thus, the short circuit current density (Jsc ) and the efficiency of the device were much better than those of the control device. Thus, introducing the alkylthio functional group in polymer is an effective method to tune the extinction coefficient of photovoltaic polymer. This provides a new path to improve photovoltaic performance without increasing active layer thickness, which will be very helpful to design advanced photovoltaic materials for high photovoltaic performance.

  8. Sustained activation of GABAA receptors in the suprachiasmatic nucleus mediates light-induced phase delays of the circadian clock: a novel function of ionotropic receptors

    PubMed Central

    Hummer, Daniel L.; Ehlen, Christopher; Larkin, Tony E.; McNeill, John K.; Pamplin, John R.; Walker, Colton A.; Walker, Phillip V.; Dhanraj, Daryl R.; Albers, H. Elliott

    2015-01-01

    The suprachiasmatic nucleus (SCN) contains a circadian clock that generates endogenous rhythmicity and entrains that rhythmicity with the day-night cycle. The neurochemical events that transduce photic input within the SCN and mediate entrainment by resetting the molecular clock have yet to be defined. Because GABA is contained in nearly all SCN neurons we tested the hypothesis that GABA serves as this signal in studies employing Syrian hamsters (Mesocricetus auratus). Activation of GABAA receptors was found to be necessary and sufficient for light to induce phase delays of the clock. Remarkably, the sustained activation of GABAA receptors for more than three consecutive hours was necessary to phase delay the clock. The duration of GABAA receptor activation required to induce phase delays would not have been predicted by either the prevalent theory of circadian entrainment or by expectations regarding the duration of ionotropic receptor activation necessary to produce functional responses. Taken together, these data identify a novel neurochemical mechanism essential for phase delaying the “master” circadian clock within the SCN as well as identifying an unprecedented action of an amino acid neurotransmitter involving the sustained activation of ionotropic receptors. PMID:25865743

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

    PubMed

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

    2016-08-01

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

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

    SciTech Connect

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

    2010-02-15

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

  11. Polymer brushes containing thermosensitive and functional groups grafted onto magnetic nano-particles for interaction and extraction of famotidine in biological samples.

    PubMed

    Ahmad Panahi, Homayon; Nasrollahi, Sara

    2014-12-10

    This study introduces a new method for grafting poly[N-isopropylacrylamide-co-allyl glycidyl/iminodiacetic] onto iron oxide nano-particles modified using 3-mercaptopropyltrimethoxysilane. The grafted nano-polymer was characterized by Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy. The parameters of pH, contact time and temperature of the grafted nano-polymer were investigated. The determination and extraction of famotidine in human biological fluids was evaluated for high accessibility to active sites on the grafted sorbent. The equilibrium adsorption data were analyzed using the Langmuir and Freundlich models. The sorption capacity of the nano-sorbent was 116 mg g(-1) at an optimum pH of 7. About 73% of famotidine was released into simulated gastric fluid by 1 h and 70% was released into simulated intestinal fluids by 30 h at 37 °C. These results show that this new magnetic grafted nano-polymer is suitable for enteric drug delivery.

  12. Ciguatoxin reduces regenerative capacity of axotomized peripheral neurons and delays functional recovery in pre-exposed mice after peripheral nerve injury

    PubMed Central

    Au, Ngan Pan Bennett; Kumar, Gajendra; Asthana, Pallavi; Tin, Chung; Mak, Yim Ling; Chan, Leo Lai; Lam, Paul Kwan Sing; Ma, Chi Him Eddie

    2016-01-01

    Ciguatera fish poisoning (CFP) results from consumption of tropical reef fish containing ciguatoxins (CTXs). Pacific (P)-CTX-1 is among the most potent known CTXs and the predominant source of CFP in the endemic region responsible for the majority of neurological symptoms in patients. Chronic and persistent neurological symptoms occur in some CFP patients, which often result in incomplete functional recovery for years. However, the direct effects of exposure to CTXs remain largely unknown. In present study, we exposed mice to CTX purified from ciguatera fish sourced from the Pacific region. P-CTX-1 was detected in peripheral nerves within hours and persisted for two months after exposure. P-CTX-1 inhibited axonal regrowth from axotomized peripheral neurons in culture. P-CTX-1 exposure reduced motor function in mice within the first two weeks of exposure before returning to baseline levels. These pre-exposed animals exhibited delayed sensory and motor functional recovery, and irreversible motor deficits after peripheral nerve injury in which formation of functional synapses was impaired. These findings are consistent with reduced muscle function, as assessed by electromyography recordings. Our study provides strong evidence that the persistence of P-CTX-1 in peripheral nerves reduces the intrinsic growth capacity of peripheral neurons, resulting in delayed functional recovery after injury. PMID:27229176

  13. Ciguatoxin reduces regenerative capacity of axotomized peripheral neurons and delays functional recovery in pre-exposed mice after peripheral nerve injury.

    PubMed

    Au, Ngan Pan Bennett; Kumar, Gajendra; Asthana, Pallavi; Tin, Chung; Mak, Yim Ling; Chan, Leo Lai; Lam, Paul Kwan Sing; Ma, Chi Him Eddie

    2016-05-27

    Ciguatera fish poisoning (CFP) results from consumption of tropical reef fish containing ciguatoxins (CTXs). Pacific (P)-CTX-1 is among the most potent known CTXs and the predominant source of CFP in the endemic region responsible for the majority of neurological symptoms in patients. Chronic and persistent neurological symptoms occur in some CFP patients, which often result in incomplete functional recovery for years. However, the direct effects of exposure to CTXs remain largely unknown. In present study, we exposed mice to CTX purified from ciguatera fish sourced from the Pacific region. P-CTX-1 was detected in peripheral nerves within hours and persisted for two months after exposure. P-CTX-1 inhibited axonal regrowth from axotomized peripheral neurons in culture. P-CTX-1 exposure reduced motor function in mice within the first two weeks of exposure before returning to baseline levels. These pre-exposed animals exhibited delayed sensory and motor functional recovery, and irreversible motor deficits after peripheral nerve injury in which formation of functional synapses was impaired. These findings are consistent with reduced muscle function, as assessed by electromyography recordings. Our study provides strong evidence that the persistence of P-CTX-1 in peripheral nerves reduces the intrinsic growth capacity of peripheral neurons, resulting in delayed functional recovery after injury.

  14. The lung function score and its components as predictors of overall survival and chronic graft-vs-host disease after allogeneic stem cell transplantation

    PubMed Central

    Ditz, Diana; Rabanus, Robert; Schulz, Christian; Wolff, Daniel; Holler, Barbara; Holler, Ernst; Hildebrandt, Gerhard Carl

    2016-01-01

    Aim To retrospectively assess if the modified lung function score (LFS) and/or its components, forced expiratory volume within the first second (FEV1) and diffusion capacity for carbon monoxide corrected for hemoglobin level (cDLCO), predict overall survival (OS) and chronic graft-vs-host-disease (cGvHD). Methods We evaluated 241 patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the University of Regensburg Transplant Center between June 1998 and July 2005 in relation to their LFS, FEV1 and cDLCO, before and after HSCT. Results Decreased OS after allo-HSCT was related to decreased pre-transplantation values of FEV1<60% (P = 0.040), cDLCO<50% of predicted value (P = 0.025), and LFS≥III (P = 0.037). It was also related to decreased FEV1 at 3 and 12 months after HSCT (P < 0.001 and P = 0.001, respectively) and increased LFS at 3 and 12 months after HSCT (P = 0.028 and P = 0.002, respectively), but not to changes of cDLCO. A higher incidence of cGvHD was related to decreased FEV1 at 6, 12, and 18 months (P = 0.069, P = 0.054, and P = 0.009, respectively) and increased LFS at 12 months (P = 0.002), but not to changes in cDLCO. Conclusions OS was related to both LFS and FEV1, but cGvHD had a stronger relation to FEV1 than to cDLCO or LFS. FEV1 alone offered more information on the outcome after allo-HSCT than LFS or cDLCO, suggesting limited value of LFS for the patients’ assessment after allo-HSCT. PMID:26935611

  15. Lipid-colloid dressing shows improved reepithelialization, pain relief, and corneal barrier function in split-thickness skin-graft donor wound healing.

    PubMed

    Tanaka, Katsuya; Akita, Sadanori; Yoshimoto, Hiroshi; Houbara, Seiji; Hirano, Akiyoshi

    2014-09-01

    Donor-site wound healing was tested with a nonadherent petrolatum- and hydrocolloid-impregnated polyester, a lipid-colloid dressing, and a nonadherent polyester dressing, supplemented with petrolatum manually by a physician onsite. Ten patients, 1 woman and 9 men (22 to 79 years old; average 58.4 ± 17.54 years), were enrolled in this prospective comparison study. The split-thickness skin graft was 14.5 ± 7.49 cm long × 8.2 ± 4.07 cm wide (5.5-27 cm long and 4.0-14.0 wide) and 14/1000 inches (0.356 mm) deep. The degree of reepithelialization in lipid-colloid dressing was significantly better than that in polyester mesh dressing, with 1.7 ± 1.00 and 2.8 ± 0.83 for the lipid-colloid dressing and polyester mesh dressing, respectively (P < .05), and degree of pain was significantly lower in lipid-colloid dressing than that in polyester dressing, 1.7 ± 1.11 and 2.9 ± 1.12 for the lipid-colloid dressing and polyester mesh dressing, respectively (P < .01). In moisture meter analyses, the values of effective contact coefficient and corneal thickness in lipid-colloid at wound healing was significantly smaller than those in polyester mesh (effective contact coefficient: 11.7 ± 1.87% and 15.6 ± 3.09% for lipid-colloid and polyester mesh, respectively, P < .05; corneal thickness: 31.1 ± 6.65 µm and 40.7 ± 8.69 µm for lipid-colloid and polyester mesh, respectively, P < .05). No significant difference was observed at 1 month after healing. The nonadherent lipid-colloid polyester dressing has superior wound healing and pain relief and demonstrates better corneal barrier function delineated by effective contact coefficient and corneal thickness at healing in split-thickness donors.

  16. Effect of mTORC1/mTORC2 inhibition on T cell function: potential role in graft-versus-host disease control.

    PubMed

    Herrero-Sánchez, Ma Carmen; Rodríguez-Serrano, Concepción; Almeida, Julia; San-Segundo, Laura; Inogés, Susana; Santos-Briz, Ángel; García-Briñón, Jesús; SanMiguel, Jesús F; Del Cañizo, Consuelo; Blanco, Belén

    2016-06-01

    The mechanistic target of rapamycin (mTOR) pathway is crucial for the activation and function of T cells, which play an essential role in the development of graft-versus-host disease (GvHD). Despite its partial ability to block mTOR pathway, the mTORC1 inhibitor rapamycin has shown encouraging results in the control of GvHD. Therefore, we considered that simultaneous targeting of both mTORC1 and mTORC2 complexes could exert a more potent inhibition of T cell activation and, thus, could have utility in GvHD control. To assess this assumption, we have used the dual mTORC1/mTORC2 inhibitors CC214-1 and CC214-2. In vitro studies confirmed the superior ability of CC214-1 versus rapamycin to block mTORC1 and mTORC2 activity and to reduce T cell proliferation. Both drugs induced a similar decrease in Th1/Th2 cytokine secretion, but CC214-1 was more efficient in inhibiting naïve T cell activation and the expression of T-cell activation markers. In addition, CC214-1 induced specific tolerance against alloantigens, while preserving anti-cytomegalovirus response. Finally, in a mouse model of GvHD, the administration of CC214-2 significantly improved mice survival and decreased GvHD-induced damages. In conclusion, the current study shows, for the first time, the immunosuppressive ability of CC214-1 on T lymphocytes and illustrates the role of CC214-2 in the allogeneic transplantation setting as a possible GvHD prophylaxis agent.

  17. Triple-functional core-shell structured upconversion luminescent nanoparticles covalently grafted with photosensitizer for luminescent, magnetic resonance imaging and photodynamic therapy in vitro.

    PubMed

    Qiao, Xiao-Fei; Zhou, Jia-Cai; Xiao, Jia-Wen; Wang, Ye-Fu; Sun, Ling-Dong; Yan, Chun-Hua

    2012-08-07

    Upconversion luminescent nanoparticles (UCNPs) have been widely used in many biochemical fields, due to their characteristic large anti-Stokes shifts, narrow emission bands, deep tissue penetration and minimal background interference. UCNPs-derived multifunctional materials that integrate the merits of UCNPs and other functional entities have also attracted extensive attention. Here in this paper we present a core-shell structured nanomaterial, namely, NaGdF(4):Yb,Er@CaF(2)@SiO(2)-PS, which is multifunctional in the fields of photodynamic therapy (PDT), magnetic resonance imaging (MRI) and fluorescence/luminescence imaging. The NaGdF(4):Yb,Er@CaF(2) nanophosphors (10 nm in diameter) were prepared via sequential thermolysis, and mesoporous silica was coated as shell layer, in which photosensitizer (PS, hematoporphyrin and silicon phthalocyanine dihydroxide) was covalently grafted. The silica shell improved the dispersibility of hydrophobic PS molecules in aqueous environments, and the covalent linkage stably anchored the PS molecules in the silica shell. Under excitation at 980 nm, the as-fabricated nanomaterial gave luminescence bands at 550 nm and 660 nm. One luminescent peak could be used for fluorescence imaging and the other was suitable for the absorption of PS to generate singlet oxygen for killing cancer cells. The PDT performance was investigated using a singlet oxygen indicator, and was investigated in vitro in HeLa cells using a fluorescent probe. Meanwhile, the nanomaterial displayed low dark cytotoxicity and near-infrared (NIR) image in HeLa cells. Further, benefiting from the paramagnetic Gd(3+) ions in the core, the nanomaterial could be used as a contrast agent for magnetic resonance imaging (MRI). Compared with the clinical commercial contrast agent Gd-DTPA, the as-fabricated nanomaterial showed a comparable longitudinal relaxivities value (r(1)) and similar imaging effect.

  18. On the stability and multi-stability of a TCP/RED congestion control model with state-dependent delay and discontinuous marking function

    NASA Astrophysics Data System (ADS)

    Zhang, Shu; Xu, Jian; Chung, Kwok-wai

    2015-05-01

    Random early detection (RED) is an effective algorithm to control the Internet congestion. However, researches on RED parameters are difficult since there are state-dependent delay and discontinuous terms on the right-hand side of the model. We smooth the model by hyperbolic tangent function and reformulate it by a switch function to keep state variables positive. Numerical simulations on the original system validates the reformulated model. The multi-stability phenomenon is observed and some suggestions on the selection of RED parameters are given to enhance the global stability of the model by numerical bifurcation continuation on the reformulated model.

  19. Polypeptide Grafted Hyaluronan: Synthesis and Characterization

    SciTech Connect

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

    2010-01-01

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

  20. Calcar bone graft

    SciTech Connect

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

    1986-01-01

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

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

    PubMed Central

    Shimizu, Yusuke; Ihara, Jyun; Kishi, Kazuo

    2016-01-01

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

  2. The Effects of Levosimendan and Sodium Nitroprusside Combination on Left Ventricular Functions After Surgical Ventricular Reconstruction in Coronary Artery Bypass Grafting Patients

    PubMed Central

    Temizturk, Zeki; Azboy, Davut; Atalay, Atakan; Atalay, Hakan; Dogan, Omer Faruk

    2016-01-01

    Objective: The aim of our study was to research the effects of levosimendan (LS) and sodium nitroprusside (SNP) combination on systolic and diastolic ventricular function after coronary artery bypass grafting (CABG) who required endoventricular patch repair (EVPR). Patients and Methods: We studied 70 patients with ischemic dilated cardiomyopathy. LS and SNP combination was administered in 35 patients (study group, SG). In the remaining patients, normal saline solution was given (placebo group, PG). Levosimendan (10µgr/kg) started 4 h prior to operation and we stopped LS before the initiation of extracorporeal circulation (ECC). During the rewarming period, we started again levosimendan (10µgr/kg) in combination with SNP (0.1-0.2 µgr/kg/min). If mean blood pressure decreased by more than 25% compared with pre-infusion values, for corrected of mean arterial pressure, the volume loading was performed using a 500 ml ringer lactate. Hemodynamic variables, inotrophyc requirement, and laboratory values were recorded. Results: Five patients died (7.14%) post-surgery (one from SG and 4 from PG) due to low cardiac out-put syndrome (LOS). At the postoperative period, cardiac output and stroke volume index was higher in SG (mean±sd;29.1±6.3 vs. 18.4±4.9 mL/min−1/m−2 (P<0.0001)). Stroke volume index (SVI) decreased from 29±10mL/m2 preoperatively to 22±14mL/m2 in the early postoperative period in group 1. This difference was statistically significant (P=0.002). Cardiac index was higher in SG (320.7±37.5 vs. 283.0±83.9 mL/min−1/m−2 (P=0.009)). The postoperative inotrophyc requirement was less in SG (5.6±2.7 vs. 10.4±2.0 mg/kg, P< 0.008), and postoperative cardiac enzyme levels were less in SG (P< 0.01). Ten patients (28.5%) in SG and 21 patients (60%) in PG required inotrophyc support (P<0.001). We used IABP in eight patients (22.8%) in SG and 17 patients (48.5%) in CG (P=0.0001). Conclusion: This study showed that LS and SNP combination impressive increase in

  3. Different regulatory and cytotoxic CD4+ T lymphocyte profiles in renal transplants with antibody-mediated chronic rejection or long-term good graft function.

    PubMed

    Giaretta, Fulvia; Bussolino, Stefania; Beltramo, Silvia; Fop, Fabrizio; Rossetti, Maura; Messina, Maria; Cantaluppi, Vincenzo; Ranghino, Andrea; Basso, Elisa; Camussi, Giovanni; Segoloni, Giuseppe Paolo; Biancone, Luigi

    2013-01-01

    Comparative analysis of the different subsets of CD4(+) T-lymphocytes may provide hints on the immunologic mechanisms operating in the long-term fate of a kidney transplant. We analyzed peripheral regulatory CD4(+) T cells (Tregs) and CD4(+) cytotoxic T lymphocytes (CTLs) in antibody-mediated chronic rejection (AMCR), in middle-term kidney transplants (2-4 years, MTKT) with good graft function and rejection-free history, in long-term kidney transplants (>15 years, LTKT) and in normal healthy subjects (NHS). Transplant groups with good prognosis (MTKT and LTKT) displayed a significant lower amount of CD4(+)CD25(high) T lymphocytes than NHS, with a trend of a higher percentage in AMCR than in MTKT and LTKT. However, CD4(+)CD25(high) Foxp3(+) cells were significantly higher in LTKT and MTKT than AMCR. Characterization of CD4(+)CD25(high) T cells showed a marked increase of intracellular CTLA-4 in the AMCR group in respect to the other transplant groups, while the expression of the surface molecule seemed to follow a reverse trend. In addition, CD27, a costimulatory receptor involved in long-term T cell survival and prevention of immune tolerance, is significantly reduced in CD4(+)CD25(high) and CD4(+)Foxp3(+) T cells in the LTKT in respect to the other transplant groups. CD4(+)CD25(high)CD45RO(+) and CD4(+)Foxp3(+)CD45RO(+) regulatory T cells with memory function were increased in LTKT compared to NHS and for the latter also in AMCR group. Finally, CD4(+)CTLs that were quantified on the basis of granzyme A expression, were more represented in AMCR patients in comparison to the other groups. Strikingly, CD27 in the CD4(+)CTLs was suppressed in LTKT and MTKT and markedly expressed in AMCR group. No significant differences in the expression of CD28 were observed among different groups. In conclusion, different profiles of Tregs and CD4(+)CTL populations correlate with different long-term conditions of kidney-transplanted patients, suggesting their role in the development

  4. Secondary oxalosis due to excess vitamin C intake: a cause of graft loss in a renal transplant recipient.

    PubMed

    Yaich, S; Chaabouni, Y; Charfeddine, K; Zaghdane, S; Kharrat, M; Kammoun, K; Makni, S; Boudawara, T; Hachicha, J

    2014-01-01

    Renal oxalate deposition can be seen with primary hyperoxaluria, malabsorptive states, ethylene glycol toxicity and, rarely, with excessive vitamin C ingestion. We report a case of secondary hyperoxaluria in which the diagnosis was not considered initially because there was no past history of urinary calculi and no evidence of nephrocalcinosis on plain X-ray of the abdomen and ultrasonography. The disease was detected and diagnosed only after kidney transplantation. Secondary oxalosis can cause graft loss or delayed graft function. Biopsy of the allograft should be carefully examined for oxalate deposits even in the absence of a family history. When oxalosis is diagnosed, intensifying hemodialysis (HD) to eliminate calcium oxalate can help in the recovery of renal function in some cases. Systematic vitamin C supplementation in HD patients should be avoided as it can be a cause of secondary oxalosis.

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

    PubMed

    Mahmoodian, Hossein; Moradi, Omid; Shariatzadeh, Behnam

    2014-02-01

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

  6. Multistability of memristive Cohen-Grossberg neural networks with non-monotonic piecewise linear activation functions and time-varying delays.

    PubMed

    Nie, Xiaobing; Zheng, Wei Xing; Cao, Jinde

    2015-11-01

    The problem of coexistence and dynamical behaviors of multiple equilibrium points is addressed for a class of memristive Cohen-Grossberg neural networks with non-monotonic piecewise linear activation functions and time-varying delays. By virtue of the fixed point theorem, nonsmooth analysis theory and other analytical tools, some sufficient conditions are established to guarantee that such n-dimensional memristive Cohen-Grossberg neural networks can have 5(n) equilibrium points, among which 3(n) equilibrium points are locally exponentially stable. It is shown that greater storage capacity can be achieved by neural networks with the non-monotonic activation functions introduced herein than the ones with Mexican-hat-type activation function. In addition, unlike most existing multistability results of neural networks with monotonic activation functions, those obtained 3(n) locally stable equilibrium points are located both in saturated regions and unsaturated regions. The theoretical findings are verified by an illustrative example with computer simulations.

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

    PubMed

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

    2014-07-01

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

  8. A Functional Polymorphism in PIN1 that Prevents its Suppression by AP4 Is Associated with Delayed Onset of Alzheimer’s disease

    PubMed Central

    Ma, Suk Ling; Tang, Nelson Leung Sang; Tam, Cindy Woon Chi; Lui, Victor Wing Cheong; Lam, Linda Chiu Wa; Chiu, Helen Fung Kum; Driver, Jane Ann; Pastorino, Lucia; Lu, Kun Ping

    2010-01-01

    Alzheimer’s disease (AD), the most common form of dementia, is characterized by the presence of neurofibrillary tangles composed of tau and senile plaques of amyloid-beta peptides (Aβ) derived from amyloid precursor protein (APP). Pin1 is a unique prolyl isomerase that has been shown to protect against age-dependent neurodegeneration by acting on phosphorylated tau and APP to suppress tangle formation and amyloidogenic APP processing. Here we report a functional polymorphism, rs2287839, in the Pin1 promoter that is significantly associated with a 3-year delay in the average age-at-onset (AAO) of late-onset AD in a Chinese population. More significantly, the Pin1 polymorphism rs2287839 is located within the consensus binding motif for the brain-selective transcription factor, AP4 (CAGCTG) and almost completely abolishes the ability of AP4 to bind and suppress the Pin1 promoter, as shown by chromatin immunoprecipitation, electrophoretic mobility shift assay and promoter luciferase assay. Moreover, overexpression or knockdown of AP4 resulted in an 80% reduction or two-fold increase in endogenous Pin1 levels, respectively. Thus, AP4 is a novel transcriptional repressor of Pin1 expression and the Pin1 promoter SNP identified in this study that prevents such suppression is associated with delayed onset of AD. These results indicate that regulation of Pin1 by AP4 plays a critical role in determining AAO of AD and might be a novel therapeutic target to delay the onset of AD. PMID:20580132

  9. Global Metabolic Profiling of Arabidopsis Polyamine Oxidase 4 (AtPAO4) Loss-of-Function Mutants Exhibiting Delayed Dark-Induced Senescence

    PubMed Central

    Sequera-Mutiozabal, Miren I.; Erban, Alexander; Kopka, Joachim; Atanasov, Kostadin E.; Bastida, Jaume; Fotopoulos, Vasileios; Alcázar, Rubén; Tiburcio, Antonio F.

    2016-01-01

    Early and more recent studies have suggested that some polyamines (PAs), and particularly spermine (Spm), exhibit anti-senescence properties in plants. In this work, we have investigated the role of Arabidopsis Polyamine Oxidase 4 (PAO4), encoding a PA back-conversion oxidase, during dark-induced senescence. Two independent PAO4 (pao4-1 and pao4-2) loss-of-function mutants have been found that accumulate 10-fold higher Spm, and this associated with delayed entry into senescence under dark conditions. Mechanisms underlying pao4 delayed senescence have been studied using global metabolic profiling by GC-TOF/MS. pao4 mutants exhibit constitutively higher levels of important metabolites involved in redox regulation, central metabolism and signaling that support a priming status against oxidative stress. During senescence, interactions between PAs and oxidative, sugar and nitrogen metabolism have been detected that additively contribute to delayed entry into senescence. Our results indicate the occurrence of metabolic interactions between PAs, particularly Spm, with cell oxidative balance and transport/biosynthesis of amino acids as a strategy to cope with oxidative damage produced during senescence. PMID:26925084

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

    Zdrahala, R J

    1996-04-01

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

  12. Bone marrow transplantation from mutant lpr/lpr mice. Functional abnormalities rather than alloantigenic differences appear to determine the development of a graft-vs.-host-like syndrome.

    PubMed

    Allen, R D; Marshall, J D; Roths, J B; Sidman, C L

    1990-09-01

    Transfer of bone marrow (BM) from autoimmunity-prone mice homozygous for the lymphoproliferation (lpr) mutation to irradiated congenic +/+ recipients has previously been shown to result in a syndrome similar to chronic graft-vs.-host (GVH) disease. It has been suggested that this syndrome may be due to an antigenic difference caused by the lpr mutation itself or to antigenic differences at loci closely linked to the lpr locus (Theofilopoulos, A. N. et al., J. Exp. Med. 1985. 162:1; Mosbach-Ozmen, L. and Loor, F., Thymus 1987. 9:197). However, the results presented here indicate that alloantigenic differences do not play a role in this syndrome. Instead, the chronic disease observed in lpr/lpr----(+/+) BM chimeras appears to develop as a result of a functional defect associated with the lpr mutation which is expressed shortly after transfer of lpr/lpr BM to irradiated recipients. This defect causes an increase in the levels of serum IgG1 and IgG2, which peak at 4-5 weeks post-transfer and then decline to normal levels by 9-10 weeks post-transfer. Inflammation similar to that observed in classic GVH reactions accompanies excess IgG production in congenic +/+ recipients but not in lpr/lpr recipients of lpr/lpr BM. We demonstrate that the GVH-like response occurring in lpr/lpr----(+/+) chimeras is dependent on mature T cells, but that either lpr/lpr or (+/+) T cells can support this reaction. These results suggest that transfer of lpr/lpr BM to normal mice causes immunoregulatory disturbances which lead to nonspecific activation of T cells. We speculate that lpr/lpr BM causes a GVH-like reaction in +/+ recipients but a systemic lupus erythematosus-like syndrome in lpr/lpr recipients because of intrinsic differences in the +/+ and lpr/lpr host environments. Considering these findings, the lpr/lpr----+/+ GVH model may be useful for analysis of factors capable of inducing undesirable reactions in clinical BM transplantation between nominally histocompatible donors and

  13. Delayed puberty.

    PubMed

    Fenichel, Patrick

    2012-01-01

    Since puberty is a long ongoing developmental process with significant individual and population differences in timing, the definition of delayed puberty for a given individual needs to rest on simple, though arbitrary criteria based on epidemiological data. Although several genes involved in the hypothalamic-pituitary-gonadal maturation cascade have been characterized recently from familial or sporadic cases of primitive isolated hypogonadotropic hypogonadism, many genes regulating puberty onset remain undetermined. In case of delayed puberty and/or primary amenorrhea, a complete clinical examination including a detailed past history will evaluate the development of secondary sex characteristics, verify the association with a growth delay and look for specific indicative features pertaining to the etiological diagnosis. This clinical check-up completed if necessary with biological, ultrasonographic, radiological and genetic investigations will try to determine which girls will have a permanent sexual infantilism of gonadal, hypophyseal or hypothalamic origin, which girls will undergo spontaneous but delayed puberty and which girls have primary amenorrhea with developed secondary sex characteristics. Therapeutic attitude will have to integrate etiological factors, statural prognosis, bone mass preservation and psychological factors.

  14. Delayed Obstruction With Asymptomatic Loss of Renal Function After Dextranomer/Hyaluronic Acid Copolymer (Deflux) Injection for Vesicoureteral Reflux: A Close Look at a Disturbing Outcome.

    PubMed

    Papagiannopoulos, Dimitri; Rosoklija, Ilina; Cheng, Earl; Yerkes, Elizabeth

    2017-03-01

    Dextranomer/hyaluronic acid copolymer (Deflux) first received Food and Drug Administration approval in 2001 for endoscopic injection in children with grade II-IV vesicoureteral reflux VUR. As experience has grown, Deflux has been used more liberally with encouraging results. We report 3 cases where Deflux was used in off-label fashion, resulting in delayed ureteral obstruction and loss of renal function (range 18-52 months postoperatively). We now place increased emphasis on the need for long-term follow-up after Deflux in both routine and complex cases, particularly in situations of off-label use.

  15. Does the end-to-end venous anastomosis offer a functional advantage over the end-to-side venous anastomosis in high-output arteriovenous grafts?

    PubMed

    Fillinger, M F; Kerns, D B; Bruch, D; Reinitz, E R; Schwartz, R A

    1990-12-01

    This study explores the hemodynamics, mechanics, and biologic response of end-to-end versus end-to-side venous anastomoses in a canine arteriovenous graft model. Femoral polytetrafluoroethylene grafts were implanted bilaterally in a paired fashion (n = 22). Detailed local hemodynamic measurements were made by use of color Doppler ultrasound imaging at 1, 4, 8, and 12 weeks after implant. Measurements included volumetric flow rate and Doppler-derived spectral window (percent window) as a measure of turbulence. Amplitude and velocity of vessel wall movement were also measured. Volume of perivascular tissue vibration quantitated kinetic energy transfer through the vessel wall. Volumetric flow rate (end to end, 1013 +/- 70 ml/min; end to side, 1015 +/- 72 ml/min), percent window (end to end, 6.6% +/- 0.6%, end to side, 5.6% +/- 0.4%) and volume of perivascular tissue vibration (end to end, 19.6 +/- 1.2 ml, end to side, 16.3 +/- 1.8 ml) were statistically equivalent in the two graft types (end to end vs end to side p greater than 0.05). Both graft types developed venous intimal-medial thickening of a similar magnitude: end to end, 0.35 +/- 0.05 mm, end to side, 0.43 +/- 0.09 mm, normal vein 0.070 +/- 0.004 mm (analysis of variance [ANOVA] p less than 0.001, p less than 0.01 for end to end or end to side vs control, end to end vs end to side p greater than 0.05 by Student-Newman-Keuls test). The best correlations with venous intimal-medial thickening were obtained from inverse percent window (r = 0.84, p less than 0.001) and volume of perivascular tissue vibration (r = 0.68, p less than 0.001). In the end to end configuration the relative amplitude of venous wall movement decreased, and the relative velocity of wall motion increased over time. We conclude that in the circumstances of this high flow arteriovenous graft model the end-to-end venous anastomosis does not significantly differ from the end-to-side venous anastomosis in terms of flow stability, turbulence, or

  16. Coexistence and local μ-stability of multiple equilibrium points for memristive neural networks with nonmonotonic piecewise linear activation functions and unbounded time-varying delays.

    PubMed

    Nie, Xiaobing; Zheng, Wei Xing; Cao, Jinde

    2016-12-01

    In this paper, the coexistence and dynamical behaviors of multiple equilibrium points are discussed for a class of memristive neural networks (MNNs) with unbounded time-varying delays and nonmonotonic piecewise linear activation functions. By means of the fixed point theorem, nonsmooth analysis theory and rigorous mathematical analysis, it is proven that under some conditions, such n-neuron MNNs can have 5(n) equilibrium points located in ℜ(n), and 3(n) of them are locally μ-stable. As a direct application, some criteria are also obtained on the multiple exponential stability, multiple power stability, multiple log-stability and multiple log-log-stability. All these results reveal that the addressed neural networks with activation functions introduced in this paper can generate greater storage capacity than the ones with Mexican-hat-type activation function. Numerical simulations are presented to substantiate the theoretical results.

  17. Bone graft substitutes.

    PubMed

    Bhatt, Reena A; Rozental, Tamara D

    2012-11-01

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

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

    PubMed Central

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

    1987-01-01

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

  19. Triple-functional core-shell structured upconversion luminescent nanoparticles covalently grafted with photosensitizer for luminescent, magnetic resonance imaging and photodynamic therapy in vitro

    NASA Astrophysics Data System (ADS)

    Qiao, Xiao-Fei; Zhou, Jia-Cai; Xiao, Jia-Wen; Wang, Ye-Fu; Sun, Ling-Dong; Yan, Chun-Hua

    2012-07-01

    Upconversion luminescent nanoparticles (UCNPs) have been widely used in many biochemical fields, due to their characteristic large anti-Stokes shifts, narrow emission bands, deep tissue penetration and minimal background interference. UCNPs-derived multifunctional materials that integrate the merits of UCNPs and other functional entities have also attracted extensive attention. Here in this paper we present a core-shell structured nanomaterial, namely, NaGdF4:Yb,Er@CaF2@SiO2-PS, which is multifunctional in the fields of photodynamic therapy (PDT), magnetic resonance imaging (MRI) and fluorescence/luminescence imaging. The NaGdF4:Yb,Er@CaF2 nanophosphors (10 nm in diameter) were prepared via sequential thermolysis, and mesoporous silica was coated as shell layer, in which photosensitizer (PS, hematoporphyrin and silicon phthalocyanine dihydroxide) was covalently grafted. The silica shell improved the dispersibility of hydrophobic PS molecules in aqueous environments, and the covalent linkage stably anchored the PS molecules in the silica shell. Under excitation at 980 nm, the as-fabricated nanomaterial gave luminescence bands at 550 nm and 660 nm. One luminescent peak could be used for fluorescence imaging and the other was suitable for the absorption of PS to generate singlet oxygen for killing cancer cells. The PDT performance was investigated using a singlet oxygen indicator, and was investigated in vitro in HeLa cells using a fluorescent probe. Meanwhile, the nanomaterial displayed low dark cytotoxicity and near-infrared (NIR) image in HeLa cells. Further, benefiting from the paramagnetic Gd3+ ions in the core, the nanomaterial could be used as a contrast agent for magnetic resonance imaging (MRI). Compared with the clinical commercial contrast agent Gd-DTPA, the as-fabricated nanomaterial showed a comparable longitudinal relaxivities value (r1) and similar imaging effect.Upconversion luminescent nanoparticles (UCNPs) have been widely used in many biochemical

  20. Click Grafting of Alkyne-containing Vinyl Polymers onto Biosynthesized Extracellular Matrix Protein Containing Azide Functionality and Adhesion Control of Human Umbilical Vein Endothelial Cells

    PubMed Central

    Yamada, Tomoki

    2015-01-01

    In vivo incorporation of a phenylalanine (Phe) analogue, p-azidophenylalanine (p-N3Phe) into an artificial extracellular matrix protein (aECM-CS5-ELF) was accomplished using a bacterial expression host that harbors the mutant phenylalanyl-tRNA synthetase (PheRS) with an enlarged binding pocket, in which the Ala294Gly/Thr251Gly mutant PheRS (PheRS**) was expressed under the control of T7 promoters. In this study, biosynthesized aECM-CS5-ELF containing p-N3Phe (aECM-CS5-ELF-N3) was coupled with alkyne-containing vinyl polymers prepared via controlled radical polymerization of three vinyl monomers, (styrene, acrylamide, and N-isopropylacrylamide) using a trithiocarbonate as the RAFT agent. Grafting of the vinyl polymers onto the aECM was accomplished via a copper-catalyzed alkyne-azide click reaction. The lower critical transition temperature (LCST) was evaluated, as well as the solubility in aqueous and organic media, which are dependent on the incorporation ratio of p-N3Phe and species of graft chains, in which the LCST behavior was altered remarkably when poly(N-isopropylacrylamide) moieties were attached as side chains. Circular dichroism measurements indicate conformational change was not induced by the grafting. Specific adhesion of human umbilical vein endothelial cells (HUVECs) onto the aECM-CS5-ELF-N3-graft-poly(N-isopropylacrylamide) composite surface and subsequent temperature-sensitive detachment were also demonstrated. PMID:26294960

  1. A gain-of-function mutation in oma-1, a C. elegans gene required for oocyte maturation, results in delayed degradation of maternal proteins and embryonic lethality.

    PubMed

    Lin, Rueyling

    2003-06-01

    In vertebrates, oocytes undergo maturation, arrest in metaphase II, and can then be fertilized by sperm. Fertilization initiates molecular events that lead to the activation of early embryonic development. In Caenorhabditis elegans, where no delay between oocyte maturation and fertilization is apparent, oocyte maturation and fertilization must be tightly coordinated. It is not clear what coordinates the transition from an oocyte to an embryo in C. elegans, but regulated turnover of oocyte-specific proteins contributes to the process. We describe here a gain-of-function mutation (zu405) in a gene that is essential for oocyte maturation, oma-1. In wild type animals, OMA-1 protein is expressed at a high level exclusively in oocytes and newly fertilized embryos and is degraded rapidly after the first mitotic division. The zu405 mutation results in improper degradation of the OMA-1 protein in embryos. In oma-1(zu405) embryos, the C blastomere is transformed to the EMS blastomere fate, resulting in embryonic lethality. We show that degradation of several maternally supplied cell fate determinants, including SKN-1, PIE-1, MEX-3, and MEX-5, is delayed in oma-1(zu405) mutant embryos. In wild type embryos, SKN-1 functions in EMS for EMS blastomere fate specification. A decreased level of maternal SKN-1 protein in the C blastomere relative to EMS is believed to be responsible for this cell expressing the C, instead of the EMS, fate. Delayed degradation of maternal SKN-1 protein in oma-1(zu405) embryos and resultant elevated levels in C blastomere is likely responsible for the observed C-to-EMS blastomere fate transformation. These observations suggest that oma-1, in addition to its role in oocyte maturation, contributes to early embryonic development by regulating the temporal degradation of maternal proteins in early C. elegans embryos.

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

    NASA Astrophysics Data System (ADS)

    Çankaya, Nevin

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

  3. Delayed puberty.

    PubMed

    Reiter, Edward O; Lee, Peter A

    2002-02-01

    Normal puberty is a time of life and a process of development that results in full adult maturity of growth, sexual development, and psychosocial achievement. Delayed puberty describes the clinical condition in which the pubertal events start late (usually > +2.5 SD later than the mean) or are attenuated in progression. The differential diagnosis includes syndromes of low gonadotropin production, usually constitutional delay of growth and maturation associated with chronic disease, but also an array of gene-mediated disorders, and syndromes of primary gonadal dysfunction with hypergonadotropic hypogonadism, including Turner and Klinefelter syndromes, and a group of acquired and genetic abnormalities. Diagnostic assessment and varied therapeutic modalities are discussed. The issues of androgen or estrogen therapy are important to assess, and growth hormone treatment remains a difficult dilemma.

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

    PubMed

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

    2015-10-01

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

  5. Optimization and reliability of multiple postlabeling delay pseudo-continuous arterial spin labeling during rest and stimulus-induced functional task activation

    PubMed Central

    Mezue, Melvin; Segerdahl, Andrew R; Okell, Thomas W; Chappell, Michael A; Kelly, Michael E; Tracey, Irene

    2014-01-01

    Arterial spin labeling (ASL) sequences that incorporate multiple postlabeling delay (PLD) times allow estimation of when arterial blood signal arrives within a region of interest. Sequences that account for such variability may improve the reliability of ASL and therefore make the technique well suited for future clinical and experimental investigations of cerebral perfusion. This study assessed the within- and between-session reproducibility of an optimized pseudo-continuous ASL (pCASL) functional magnetic resonance imaging (FMRI) sequence that incorporates multiple postlabeling delays (multi-PLD pCASL). Healthy subjects underwent four identical scans separated by 30 minutes, 1 week, and 1 month using multi-PLD pCASL to image absolute perfusion (cerebral blood flow (CBF) and arterial arrival time (AAT)) during both rest and a visual-cued motor task. We show good test-retest reliability, with strong consistency across subjects and sessions during rest (inter-session within-subject coefficient of variation: gray matter (GM) CBF=6.44% GM AAT=2.20%). We also report high sensitivity and reproducibility during the functional task, where we show robust task-related decreases in AAT corresponding with regions of increased CBF. Importantly, these results give insight into optimal PLD selection for future investigations using single-PLD ASL to image different brain regions, and highlight the necessity of multi-PLD ASL when imaging perfusion in the whole brain. PMID:25269517

  6. Stability and Hopf Bifurcation of a Delayed Density-Dependent Predator-Prey System with Beddington-DeAngelis Functional Response

    NASA Astrophysics Data System (ADS)

    Li, Haiyin; Meng, Gang; She, Zhikun

    In this paper, we investigate the stability and Hopf bifurcation of a delayed density-dependent predator-prey system with Beddington-DeAngelis functional response, where not only the prey density dependence but also the predator density dependence are considered such that the studied predator-prey system conforms to the realistically biological environment. We start with the geometric criterion introduced by Beretta and Kuang [2002] and then investigate the stability of the positive equilibrium and the stability switches of the system with respect to the delay parameter τ. Especially, we generalize the geometric criterion in [Beretta & Kuang, 2002] by introducing the condition (i‧) which can be assured by the condition (H2‧), and adopting the technique of lifting to define the function S˜n(τ) for alternatively determining stability switches at the zeroes of S˜n(τ)s. Afterwards, by the Poincaré normal form for Hopf bifurcation in [Kuznetsov, 1998] and the bifurcation formulae in [Hassard et al., 1981], we qualitatively analyze the properties for the occurring Hopf bifurcations of the system (3). Finally, an example with numerical simulations is given to illustrate the obtained results.

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

    PubMed

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

    2013-12-01

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

  8. R&D for graft adsorbents by radiation processing

    NASA Astrophysics Data System (ADS)

    Seko, Noriaki; Tamada, Masao

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

  9. Cyclic hydrostatic pressure promotes a stable cartilage phenotype and enhances the functional development of cartilaginous grafts engineered using multipotent stromal cells isolated from bone marrow and infrapatellar fat pad.

    PubMed

    Carroll, S F; Buckley, C T; Kelly, D J

    2014-06-27

    The objective of this study was to investigate how joint specific biomechanical loading influences the functional development and phenotypic stability of cartilage grafts engineered in vitro using stem/progenitor cells isolated from different source tissues. Porcine bone marrow derived multipotent stromal cells (BMSCs) and infrapatellar fat pad derived multipotent stromal cells (FPSCs) were seeded in agarose hydrogels and cultured in chondrogenic medium, while simultaneously subjected to 10MPa of cyclic hydrostatic pressure (HP). To mimic the endochondral phenotype observed in vivo with cartilaginous tissues engineered using BMSCs, the culture media was additionally supplemented with hypertrophic factors, while the loss of phenotype observed in vivo with FPSCs was induced by withdrawing transforming growth factor (TGF)-β3 from the media. The application of HP was found to enhance the functional development of cartilaginous tissues engineered using both BMSCs and FPSCs. In addition, HP was found to suppress calcification of tissues engineered using BMSCs cultured in chondrogenic conditions and acted to maintain a chondrogenic phenotype in cartilaginous grafts engineered using FPSCs. The results of this study point to the importance of in vivo specific mechanical cues for determining the terminal phenotype of chondrogenically primed multipotent stromal cells. Furthermore, demonstrating that stem or progenitor cells will appropriately differentiate in response to such biophysical cues might also be considered as an additional functional assay for evaluating their therapeutic potential.

  10. Rapid Memory T-cell Reconstitution Recapitulating CD45RA-depleted Haploidentical Transplant Graft Content in Patients with Hematologic Malignancies

    PubMed Central

    Triplett, Brandon M; Shook, David R; Eldridge, Paul; Li, Ying; Kang, Guolian; Dallas, Mari; Hartford, Christine; Srinivasan, Ashok; Chan, Wing Keung; Suwannasaen, Duangchan; Inaba, Hiroto; Pui, Ching-Hon; Leung, Wing

    2015-01-01

    T-cell depletion of an HLA-haploidentical graft is often used to prevent graft-vs.-host disease (GvHD), but the procedure may lead to increased graft failure, relapse, and infections due to delayed immune recovery. We hypothesized that selective depletion of the CD45RA+ subset can effectively reduce GvHD through removal of naïve T cells, while providing improved donor immune reconstitution through adoptive transfer of CD45RA– memory T cells. Herein, we present results from the first 17 patients with poor-prognosis hematologic malignancy who received haploidentical donor transplantation with CD45RA-depleted progenitor cell grafts following a novel reduced intensity conditioning regimen without total body irradiation or serotherapy. Extensive depletion of CD45RA+ T cells and B cells, with preservation of abundant memory T cells, was consistently achieved in all 17 products. Neutrophil engraftment (median day +10) and full donor chimerism (median day +11) was rapidly achieved post-transplantation. Early T-cell reconstitution directly correlated with the CD45RA-depleted graft content. T-cell function recovered rapidly with broad TCR Vβ spectra. There was no infection-related mortality in this heavily pretreated population, and no patient developed acute GvHD despite infusion of a median of >100 million per kilogram haploidentical T cells. PMID:25665048

  11. The role of "indirect" recognition in initiating rejection of skin grafts from major histocompatibility complex class II-deficient mice.

    PubMed Central

    Auchincloss, H; Lee, R; Shea, S; Markowitz, J S; Grusby, M J; Glimcher, L H

    1993-01-01

    In vitro studies have revealed several pathways by which T cells can respond to alloantigens, including CD4+ direct responses to allogeneic class II antigens, CD8+ direct responses to allogeneic class I antigens, and CD4+ "indirect" responses to peptides of alloantigens presented in association with responder class II molecules. In vivo studies of skin graft rejection, however, have so far provided clear evidence for the contribution of only the two direct pathways and not for indirect recognition. We have used major histocompatibility complex class II-deficient mice as donors to test the role of indirect recognition in rejection of skin grafts. Class II-deficient skin was always rejected without delay by normal recipients. Removal of recipient CD8+ cells (to leave the animals dependent on CD4+ function) or depletion of recipient CD4+ cells revealed that CD4+ cells were usually involved and sometimes absolutely required in this rapid rejection. Since the donor grafts lacked class II antigens, the CD4+ cells must have recognized donor antigens presented in association with recipient class II molecules. These results therefore indicate that indirect recognition can initiate rapid skin graft rejection. PMID:8475083

  12. Using an end-to-side interposed sural nerve graft for facial nerve reinforcement after vestibular schwannoma resection. Technical note.

    PubMed

    Samii, Madjid; Koerbel, Andrei; Safavi-Abbasi, Sam; Di Rocco, Federico; Samii, Amir; Gharabaghi, Alireza

    2006-12-01

    Increasing rates of facial and cochlear nerve preservation after vestibular schwannoma surgery have been achieved in the last 30 years. However, the management of a partially or completely damaged facial nerve remains an important issue. In such a case, several immediate or delayed repair techniques have been used. On the basis of recent studies of successful end-to-side neurorrhaphy, the authors applied this technique in a patient with an anatomically preserved but partially injured facial nerve during vestibular schwannoma surgery. The authors interposed a sural nerve graft to reinforce the facial nerve whose partial anatomical continuity had been preserved. On follow-up examinations 18 months after surgery, satisfactory cosmetic results for facial nerve function were observed. The end-to-side interposed nerve graft appears to be a reasonable alternative in cases of partial facial nerve injury, and might be a future therapeutic option for other cranial nerve injuries.

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

    SciTech Connect

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

    1982-04-01

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

  14. Variability of the Tropospheric-Delay Temporal Structure Function of Radio Signals from the Global Navigation Satellite Systems Versus Tropospheric Surface Layer Parameters

    NASA Astrophysics Data System (ADS)

    Khutorov, V. E.; Teptin, G. M.; Zhuravlev, A. A.; Khutorova, O. G.

    2016-11-01

    We present the results of a four-year (2009-2012) study of the decimeter radio wave propagation using signals from the global navigation satellite system (GNSS) and simultaneous measurements of the tropospheric surface layer parameters in the city of Kazan. Inter- and intra-annual variabilities of the temporal structure functions of the zenith tropospheric delay (ZTD) of decimeter radio waves are analyzed. It has been found that the contribution of irregularities with time scales of up to 24 h to the ZTD fluctuation variance varies, depending on the surface weather parameters (temperature and pressure). Correlation coefficient between the approximation exponents of the ZTD temporal structure function of decimeter radio waves and surface temperature reaches 0.77 for fluctuations with time scales of up to 8 h. It has been established that synoptic processes and the underlying surface affect the formation of mesoscale fluctuations on the phase path of radio signals from the navigation satellite systems.

  15. Noninvasive blood glucose sensing using near infra-red spectroscopy and artificial neural networks based on inverse delayed function model of neuron.

    PubMed

    Ramasahayam, Swathi; Koppuravuri, Sri Haindavi; Arora, Lavanya; Chowdhury, Shubhajit Roy

    2015-01-01

    In this paper, a non-invasive blood glucose sensing system is presented using near infra-red(NIR) spectroscopy. The signal from the NIR optodes is processed using artificial neural networks (ANN) to estimate the glucose level in blood. In order to obtain accurate values of the synaptic weights of the ANN, inverse delayed (ID) function model of neuron has been used. The ANN model has been implemented on field programmable gate array (FPGA). Error in estimating glucose levels using ANN based on ID function model of neuron implemented on FPGA, came out to be 1.02 mg/dl using 15 hidden neurons in the hidden layer as against 5.48 mg/dl using ANN based on conventional neuron model.

  16. Endovascular Aortic Aneurysm Repair with Chimney and Snorkel Grafts: Indications, Techniques and Results

    SciTech Connect

    Patel, Rakesh P.; Katsargyris, Athanasios Verhoeven, Eric L. G.; Adam, Donald J.; Hardman, John A.

    2013-12-15

    The chimney technique in endovascular aortic aneurysm repair (Ch-EVAR) involves placement of a stent or stent-graft parallel to the main aortic stent-graft to extend the proximal or distal sealing zone while maintaining side branch patency. Ch-EVAR can facilitate endovascular repair of juxtarenal and aortic arch pathology using available standard aortic stent-grafts, therefore, eliminating the manufacturing delays required for customised fenestrated and branched stent-grafts. Several case series have demonstrated the feasibility of Ch-EVAR both in acute and elective cases with good early results. This review discusses indications, technique, and the current available clinical data on Ch-EVAR.

  17. Engineering anatomically shaped human bone grafts.

    PubMed

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

    2010-02-23

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

  18. COMPOUNDING PHARMACIES' POTENTIAL TO CREATE Graft Storage Solutions for Bypass Surgeries.

    PubMed

    Guth, Michael A S

    2015-01-01

    Several studies have addressed the optimal storage conditions for vascular grafts during bypass surgery. These studies have repeatedly shown that placing vascular graft conduits in isotonic saline solutions, and to a lesser extent in heparinized autologous blood, leads to a profound decline in endothelial cell viability. Endothelial damage to vein grafts can occur at multiple points during a coronary artery bypass graft surgery procedure: graft harvesting, handling, flushing, storage, anastomosis, and arterialization (e.g., damage caused by exposure to arterial blood pressure). This damage to endothelial cells causes the release of pro-inflammatory chemical signals that trigger thrombosis, intimal hyperplasia, and accelerated graft atherosclerosis, all of which ultimately contribute to graft failure. Cardiothoracic surgeons performing coronary artery bypass graft surgery and vascular surgeons performing peripheral artery bypass graft surgery have attempted to overcome the damage to the vascular grafts by using buffers to maintain the physiological pH of the storage solution. However, the endothelial layers in the grafts would benefit from having proper oxygenation and antioxidants added to the storage solution. Compounding pharmacies can perform a vital role in ensuring the patency of the vascular grafts by creating compounded flushing and storage solutions that have an optimal mix of nitric oxide substrates, antioxidants, and other nutrients for the endothelium. Maintaining structural and functional viability of the endothelia in grafts by using an appropriate vessel storage medium would lead to improved long-term graft patency.

  19. Impaired exercise capacity after lung transplantation is related to delayed recovery of muscle strength.

    PubMed

    Walsh, James R; Chambers, Daniel C; Davis, Rebecca J; Morris, Norman R; Seale, Helen E; Yerkovich, Stephanie T; Hopkins, Peter M A

    2013-01-01

    Lung transplant recipients report reduced exercise capacity despite satisfactory graft function. We analysed changes in lung function, six-min walk distance (6MWD), and quadriceps strength in the first 26-wk post-transplant and examined what factors predict 6MWD recovery. All lung transplant recipients at a single institution between June 2007 and January 2011 were considered for inclusion. Lung function, 6MWD, and quadriceps strength corrected for body weight (QS%) were recorded pre- and two-, six-, 13-, and 26-wk post-transplant. Fifty recipients, of mean (± SD) age 42 (± 13) yr, were studied. Mean FEV1 % and 6MWD improved from 26.4% to 88.9% and from 397 to 549 m at 26 wk, respectively (both p < 0.001). QS% declined in the first two wk but had improved to above pre-transplant levels by 26 wk (p = 0.027). On multivariate analysis (n = 35), lower pre-transplant exercise capacity and greater recovery in muscle strength explained most of the improvement in exercise capacity. Delayed recovery of exercise capacity after lung transplantation is unrelated to delay in improvement in graft function, but occurs secondary to the slow recovery of muscle strength. Our findings show that additional controlled trials are needed to better understand the influence of exercise rehabilitation on improvement in exercise capacity post-transplantation.

  20. α2δ-1 Gene Deletion Affects Somatosensory Neuron Function and Delays Mechanical Hypersensitivity in Response to Peripheral Nerve Damage

    PubMed Central

    Patel, Ryan; Bauer, Claudia S.; Nieto-Rostro, Manuela; Margas, Wojciech; Ferron, Laurent; Chaggar, Kanchan; Crews, Kasumi; Ramirez, Juan D.; Bennett, David L. H.; Schwartz, Arnold; Dickenson, Anthony H.

    2013-01-01

    The α2δ-1 subunit of voltage-gated calcium channels is upregulated after sensory nerve injury and is also the therapeutic target of gabapentinoid drugs. It is therefore likely to play a key role in the development of neuropathic pain. In this study, we have examined mice in which α2δ-1 gene expression is disrupted, to determine whether α2δ-1 is involved in various modalities of nociception, and for the development of behavioral hypersensitivity after partial sciatic nerve ligation (PSNL). We find that naive α2δ-1−/− mice show a marked behavioral deficit in mechanical and cold sensitivity, but no change in thermal nociception threshold. The lower mechanical sensitivity is mirrored by a reduced in vivo electrophysiological response of dorsal horn wide dynamic range neurons. The CaV2.2 level is reduced in brain and spinal cord synaptosomes from α2δ-1−/− mice, and α2δ-1−/− DRG neurons exhibit lower calcium channel current density. Furthermore, a significantly smaller number of DRG neurons respond to the TRPM8 agonist menthol. After PSNL, α2δ-1−/− mice show delayed mechanical hypersensitivity, which only develops at 11 d after surgery, whereas in wild-type littermates it is maximal at the earliest time point measured (3 d). There is no compensatory upregulation of α2δ-2 or α2δ-3 after PSNL in α2δ-1−/− mice, and other transcripts, including neuropeptide Y and activating transcription factor-3, are upregulated normally. Furthermore, the ability of pregabalin to alleviate mechanical hypersensitivity is lost in PSNL α2δ-1−/− mice. Thus, α2δ-1 is essential for rapid development of mechanical hypersensitivity in a nerve injury model of neuropathic pain. PMID:24133248

  1. α2δ-1 gene deletion affects somatosensory neuron function and delays mechanical hypersensitivity in response to peripheral nerve damage.

    PubMed

    Patel, Ryan; Bauer, Claudia S; Nieto-Rostro, Manuela; Margas, Wojciech; Ferron, Laurent; Chaggar, Kanchan; Crews, Kasumi; Ramirez, Juan D; Bennett, David L H; Schwartz, Arnold; Dickenson, Anthony H; Dolphin, Annette C

    2013-10-16

    The α2δ-1 subunit of voltage-gated calcium channels is upregulated after sensory nerve injury and is also the therapeutic target of gabapentinoid drugs. It is therefore likely to play a key role in the development of neuropathic pain. In this study, we have examined mice in which α2δ-1 gene expression is disrupted, to determine whether α2δ-1 is involved in various modalities of nociception, and for the development of behavioral hypersensitivity after partial sciatic nerve ligation (PSNL). We find that naive α2δ-1(-/-) mice show a marked behavioral deficit in mechanical and cold sensitivity, but no change in thermal nociception threshold. The lower mechanical sensitivity is mirrored by a reduced in vivo electrophysiological response of dorsal horn wide dynamic range neurons. The CaV2.2 level is reduced in brain and spinal cord synaptosomes from α2δ-1(-/-) mice, and α2δ-1(-/-) DRG neurons exhibit lower calcium channel current density. Furthermore, a significantly smaller number of DRG neurons respond to the TRPM8 agonist menthol. After PSNL, α2δ-1(-/-) mice show delayed mechanical hypersensitivity, which only develops at 11 d after surgery, whereas in wild-type littermates it is maximal at the earliest time point measured (3 d). There is no compensatory upregulation of α2δ-2 or α2δ-3 after PSNL in α2δ-1(-/-) mice, and other transcripts, including neuropeptide Y and activating transcription factor-3, are upregulated normally. Furthermore, the ability of pregabalin to alleviate mechanical hypersensitivity is lost in PSNL α2δ-1(-/-) mice. Thus, α2δ-1 is essential for rapid development of mechanical hypersensitivity in a nerve injury model of neuropathic pain.

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

    SciTech Connect

    Daley, J.P.; Nakamura, I.

    1984-04-01

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

  3. Symptoms of ADHD in children with high-functioning autism are related to impaired verbal working memory and verbal delayed recall.

    PubMed

    Andersen, Per Normann; Hovik, Kjell Tore; Skogli, Erik Winther; Egeland, Jens; Oie, Merete

    2013-01-01

    Symptoms similar to those found in Attention-Deficit/Hyperactivity Disorder (ADHD) often occur in children with Autism Spectrum Disorders (ASD). The objective of the current study was to compare verbal working memory, acquisition and delayed recall in children with High-Functioning Autism (HFA) to children with ADHD and typically developing children (TDC). Thirty-eight children with HFA, 79 with ADHD and 50 TDC (age 8-17) were assessed with a letter/number sequencing task and a verbal list-learning task. To investigate the possible influence of attention problems in children with HFA, we divided the HFA group into children with (HFA+) or without (HFA-) "attention problems" according to the Child Behaviour Checklist 6-18. The children with HFA+ displayed significant impairment compared to TDC on all three neurocognitive measures, while the children with HFA- were significantly impaired compared to TDC only on the working memory and acquisition measures. In addition, the HFA+ group scored significantly below the HFA- group and the ADHD group on the verbal working memory and delayed recall measures. The results support the proposition that children with HFA+, HFA-, and ADHD differ not only on a clinical level but also on a neurocognitive level which may have implications for treatment.

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

    SciTech Connect

    Jansen, B.; Ellinghorst, G.

    1985-11-01

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

  5. Lymphocyte dysfunction in chronic graft-versus-host disease

    SciTech Connect

    Saxon, A.; McIntyre, R.E.; Stevens, R.H.; Gale, R.P.

    1981-10-01

    Three recipients of HLA-identical bone marrow transplants developed chronic graft-versus-host disease (cGVHD) and hypergammaglobulinemia. All three had evidence of abnormal B-lymphocyte function, including a polyclonal increase in immunoglobulins (Ig), antinuclear antibodies, rheumatoid factor, lymphocytotoxins, and increased immune complexes. T-lymphocyte function was also abnormal, including decreased mitogen reactivity and delayed cutaneous hypersensitivity. The cellular basis of these immune abnormalities was studied in an in vitro system in which we analyzed spontaneous pokeweed mitogen (PWM) driven Ig synthesis. Multiple defects in both T- and B-lymphocyte function were detected. In contrast to normal B cells, circulating B cells from all three patients with cGVHD spontaneously synthesized in vitro greater than 200 ng of IgG and in two of the three greater than 175 ng of IgM. This increase in spontaneous Ig synthesis was not due to a deficiency of regulatory cells, since T cells from the three patients suppressed spontaneous Ig synthesis in a normal fashion. In contrast to this increased spontaneous Ig synthesis, the response of the patients' B cells to PWM-driven Ig synthesis was normal. Using the PWM system we demonstrated several defects in these patients' T cells, including increased suppressor activity and decreased helper cell activity. These data indicate that some patients with cGVHD have multiple defects in both T- and B-cell function that may contribute to their profound immune deficiency.

  6. Autologous Fat Grafting for Treating Blepharoplasty-induced Lower Eyelid Retraction

    PubMed Central

    Bernardini, Francesco P.; Fezza, John; Hartstein, Morris E.

    2016-01-01

    Summary: Autologous fat grafting for blepharoplasty-induced lower eyelid retraction offers potential for a long-term solution while avoiding the morbidity associated with posterior lamellar spacer grafts. By combining traditional methods of lifting the retracted lower eyelid with autologous fat grafting, both functional and aesthetic concerns can be successfully addressed in these patients. PMID:28293531

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

    PubMed

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

    2012-09-01

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

  8. Giant venous aneurysm jeopardising internal mammary arterial graft patency

    PubMed Central

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

    2012-01-01

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

  9. Gas-phase and liquid-phase pre-irradiation grafting of AAc onto LDPE and HDPE films for pervaporation membranes

    NASA Astrophysics Data System (ADS)

    Zhigong, Rao; Guixiang, Li; Sugo, Takanobu; Okamoto, Jiro

    A study has been made on gas-phase and liquid-phase pre-irradiation grafting of acrylic acid onto LDPE and HDPE films for pervaporation membranes of ethanol-water mixtures. It was found that the degree of grafting, percent volume change of grafted membranes and length of grafting chains depend on the methods of grafting, crystal state of substrate films and diffusion rate of the monomer in the films. The pervaporation characteristics of grafted membranes is influenced directly by the surface hydrophilicity of grafted membranes, temperature of the feed, degree of grafting, crosslinking of grafted chains and alkaline metal ions in the functional groups. The potassium ion exchange membrane of HDPE synthesized by gas-phase grafting has better pervaporation efficiency. At 80 wt% ethanol in the feed, 25°C feed temperature and 70% degree of grafting a grafted membrane has a 0.65 kg/m 2h flux and a separation factor of 20.

  10. Hot Executive Function Following Moderate-to-Late Preterm Birth: Altered Delay Discounting at 4 Years of Age

    ERIC Educational Resources Information Center

    Hodel, Amanda S.; Brumbaugh, Jane E.; Morris, Alyssa R.; Thomas, Kathleen M.

    2016-01-01

    Interest in monitoring long-term neurodevelopmental outcomes of children born moderate-to-late preterm (32-36 weeks gestation) is increasing. Moderate-to-late preterm birth has a negative impact on academic achievement, which may relate to differential development of executive function (EF). Prior studies reporting deficits in EF in preterm…

  11. Cannabinoid CB2 receptor (CB2R) stimulation delays rubrospinal mitochondrial-dependent degeneration and improves functional recovery after spinal cord hemisection by ERK1/2 inactivation.

    PubMed

    Latini, L; Bisicchia, E; Sasso, V; Chiurchiù, V; Cavallucci, V; Molinari, M; Maccarrone, M; Viscomi, M T

    2014-09-04

    Spinal cord injury (SCI) is a devastating condition of CNS that often results in severe functional impairments for which there are no restorative therapies. As in other CNS injuries, in addition to the effects that are related to the primary site of damage, these impairments are caused by degeneration of distal regions that are connected functionally to the primary lesion site. Modulation of the endocannabinoid system (ECS) counteracts this neurodegeneration, and pharmacological modulation of type-2 cannabinoid receptor (CB2R) is a promising therapeutic target for several CNS pathologies, including SCI. This study examined the effects of CB2R modulation on the fate of axotomized rubrospinal neurons (RSNs) and functional recovery in a model of spinal cord dorsal hemisection (SCH) at the cervical level in rats. SCH induced CB2R expression, severe atrophy, and cell death in contralateral RSNs. Furthermore, SCH affected molecular changes in the apoptotic cascade in RSNs - increased cytochrome c release, apoptosome formation, and caspase-3 activity. CB2R stimulation by its selective agonist JWH-015 significantly increased the bcl-2/bax ratio, reduced cytochrome c release, delayed atrophy and degeneration, and improved spontaneous functional recovery through ERK1/2 inactivation. These findings implicate the ECS, particularly CB2R, as part of the endogenous neuroprotective response that is triggered after SCI. Thus, CB2R modulation might represent a promising therapeutic target that lacks psychotropic effects and can be used to exploit ECS-based approaches to counteract neuronal degeneration.

  12. Grafts for Ridge Preservation

    PubMed Central

    Jamjoom, Amal; Cohen, Robert E.

    2015-01-01

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

  13. Poly(2-hydroxyethyl methacrylate) (PHEMA) grafted polyethylene/polypropylene (PE/PP) nonwoven fabric by γ-initiation: Synthesis, characterization and benefits of RAFT mediation

    NASA Astrophysics Data System (ADS)

    Kodama, Yasko; Barsbay, Murat; Güven, Olgun

    2014-12-01

    Polyethylene/polypropylene (PE/PP) nonwoven fabrics were functionalized by γ-initiated RAFT mediated grafting of 2-hydroxyethyl methacrylate (HEMA), and the characterization of the grafted samples was carried out using various techniques. FTIR and XPS analysis showed an increase in the oxygenated content till a certain degree of grafting. The results implied a grafting process following the concept of ‘front mechanism’. The initial grafting occurred on the topmost surface layer, and then moved further into the bulk of the polymer matrix. Reversible addition-fragmentation chain transfer (RAFT) mediated grafting yielded a better controlled grafting when compared to those obtained in conventional grafting.

  14. Activation of liver X receptor delayed the retinal degeneration of rd1 mice through modulation of the immunological function of glia.

    PubMed

    He, Xiao; Sun, Dayu; Chen, Siyu; Xu, Haiwei

    2017-03-29

    Retinal degeneration (RD), including retinitis pigmentosa (RP), is an inherited eye disease characterized by progressive degeneration of photoreceptors. Recently, immune cells, including microglia, Müller cells and astrocytes, in degenerative retina are demonstrated to play key roles in the development of RD and can be used as potential therapeutic targets. Liver X receptors (LXRs) are important immuno-inflammatory response transcription factors that have been reported to be a new potential therapeutic drug target for neurodegenerative diseases. However, the potential therapeutic utility of LXRs for RP has not been evaluated. In the present study, Pde6β (rd1) mice received intraperitoneal injections of T0901317 (T0, 50 mg/kg/d) or vehicle (2% DMSO) for 7 days with age-matched C57/BL6 mice as controls. The effect of T0 was examined by quantitating photoreceptor apoptosis, microglial density and the expression of inflammatory mediators; the underlying mechanisms were then explored with a microarray assay. T0 markedly delayed apoptosis of the photoreceptors, partially through suppressing the activation of microglia and the gliosis of Müller cells, and decreased the expression levels of IL-6, iNOS, COX-2 and ENG in rd1 mice; as a result, the visual function of T0-treated rd1 mice measured with electroretinograms (ERG) was preserved for a longer time than that of vehicle-treated rd1 mice. The microarray assay showed that the Janus kinase/Signal Transducer and Activator of Transcription (JAK-STAT) signaling pathway was significantly affected in the retina of rd1 mice with T0 treatment. Our data suggested that T0 modulated the immunologic function of glia cells in the degenerative retina through the JAK3/STAT pathway and delayed the apoptosis of photoreceptors.

  15. Graft-versus-host disease

    MedlinePlus

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

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

    PubMed

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

    2016-05-24

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

  17. EARLY REGENERATION DETERMINES LONG‐TERM GRAFT SITE MORPHOLOGY AND FUNCTION AFTER RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT WITH SEMITENDINOSUS‐GRACILIS AUTOGRAFT: A CASE SERIES

    PubMed Central

    Snyder‐Mackler, Lynn; Axe, Michael J.; Buchanan, Thomas S.

    2013-01-01

    Purpose/Background: The semitendinosus‐gracilis tendon autograft is often used to reconstruct the anterior cruciate ligament. Tendon regeneration appears to occur for most individuals in the short term, but little is known about the long‐term effects of graft harvest. The purpose of this study was to describe the effect of semitendinosis‐gracilis tendon graft harvest on muscle and tendon morphology at least five years following reconstruction in a case series. Methods: Magnetic resonance images were taken of the knees of three subjects at least five years following anterior cruciate ligament reconstruction. These subjects represented the different regeneration patterns at the time of return‐to‐sport. Muscle and tendon morphology were analyzed by calculating the volume, peak cross‐sectional area, and length of the knee flexors. Muscle and tendon morphological changes were analyzed individually, and then in combination as defined as a knee flexor group. Results: Muscle and tendon regeneration continued in those tendons that had begun regeneration at the time of return‐to‐sports in two subjects. There was significant additional muscle degeneration in those muscles whose tendons had not regenerated at the time of return‐to‐sports, in the remaining subject. Compensatory hypertrophy of the remaining knee flexors restored the knee flexor group to near preoperative peak cross‐sectional area and volume across the each of the three case subjects. Conclusions: Knee flexor morphology at the time of return‐to‐sports foreshadowed the long‐term outcome in the three studied subjects. Preservation of the tendon sheath in situ may play a role in tendon regeneration. When tendon regeneration did not occur, fatty infiltration of the muscle may be a worst‐case outcome. Semitendinosus‐gracilis muscle synergists demonstrated hypertrophy, perhaps in an effort to compensate for knee flexor group morphology deficits that existed after Semitendinosus gracilis

  18. Social Competence in Children with Borderline Intellectual Functioning: Delayed Development of Theory of Mind Across All Complexity Levels

    PubMed Central

    Baglio, Gisella; Blasi, Valeria; Sangiuliano Intra, Francesca; Castelli, Ilaria; Massaro, Davide; Baglio, Francesca; Valle, Annalisa; Zanette, Michela; Marchetti, Antonella

    2016-01-01

    Borderline intellectual functioning (BIF) is characterized by heterogeneous cognitive difficulties, with an intelligence quotient (IQ) between 70 and 85 points, and a failure to meet the developmental and sociocultural standards for personal independence and social responsibility required in daily life. The fact that this population still remain a marginal clinical category, with no ad hoc diagnostic and therapeutic approaches, has stimulated the present research. Our goal was to study children with BIF investigating the development of Theory of Mind (ToM) as a pillar of social competence. Children with BIF (N = 28, 16 male/12 female, and mean age 9.46 ± 1.26 years) and children with typical development (TD; N = 31, 17 male/14 female; mean age 8.94 years ± 0.99) underwent a neurocognitive assessment and a ToM assessment. Children with BIF showed a significant lower performance across all the levels of ToM development investigated compared to the control group, and a correlation between executive functions and the advanced levels of ToM reasoning. These results constitute a first step in the direction of defining the clinical profile of children with BIF concerning ToM development, opening the way to future interventions in order to support the developmental evolution of this population in an adaptive direction. PMID:27818637

  19. Social Competence in Children with Borderline Intellectual Functioning: Delayed Development of Theory of Mind Across All Complexity Levels.

    PubMed

    Baglio, Gisella; Blasi, Valeria; Sangiuliano Intra, Francesca; Castelli, Ilaria; Massaro, Davide; Baglio, Francesca; Valle, Annalisa; Zanette, Michela; Marchetti, Antonella

    2016-01-01

    Borderline intellectual functioning (BIF) is characterized by heterogeneous cognitive difficulties, with an intelligence quotient (IQ) between 70 and 85 points, and a failure to meet the developmental and sociocultural standards for personal independence and social responsibility required in daily life. The fact that this population still remain a marginal clinical category, with no ad hoc diagnostic and therapeutic approaches, has stimulated the present research. Our goal was to study children with BIF investigating the development of Theory of Mind (ToM) as a pillar of social competence. Children with BIF (N = 28, 16 male/12 female, and mean age 9.46 ± 1.26 years) and children with typical development (TD; N = 31, 17 male/14 female; mean age 8.94 years ± 0.99) underwent a neurocognitive assessment and a ToM assessment. Children with BIF showed a significant lower performance across all the levels of ToM development investigated compared to the control group, and a correlation between executive functions and the advanced levels of ToM reasoning. These results constitute a first step in the direction of defining the clinical profile of children with BIF concerning ToM development, opening the way to future interventions in order to support the developmental evolution of this population in an adaptive direction.

  20. Bone Grafts in Craniofacial Surgery

    PubMed Central

    Elsalanty, Mohammed E.; Genecov, David G.

    2009-01-01

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

  1. Grafting effects on vegetable quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Hemodynamic Responses to Two Different Anesthesia Regimens in Compromised Left Ventricular Function Patients Undergoing Coronary Artery Bypass Graft Surgery: Etomidate-Midazolam Versus Propofol-Ketamine

    PubMed Central

    Aghdaii, Nahid; Ziyaeifard, Mohsen; Faritus, Seyedeh Zahra; Azarfarin, Rasoul

    2015-01-01

    Background: Various methods have been suggested to prevent hemodynamic instability caused by propofol and adverse effects caused by etomidate induction. The current study evaluated hemodynamic effects of propofol-ketamine mixture in comparison to etomidate-midazolam mixture during anesthesia induction. Objectives: The aim of this study was to evaluate the hemodynamic effects of etomidate-midazolam by comparing it with propofol-ketamine for the induction of anesthesia in patients with left ventricular dysfunction undergoing coronary artery bypass graft surgery. Patients and Methods: One-hundred patients aged between 40 and 65 with coronary artery disease and low ejection fraction scheduled for elective coronary artery bypass surgery participated in this study. The patients were randomly allotted to one of the two groups to receive either propofol-ketamine or etomidate-midazolam combination. Two groups were compared for pain on injection and myoclonus, Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), Cardiac Index (CI) and Systemic Vascular Resistance (SVR), before and one minute after induction of anesthesia, and one, three and five minutes after intubation. Results: Incidence of pain on injection (2 - 4%) and myoclonus (10%) was less in both groups. The hemodynamic response was similar in the two groups for all variables over the time interval, except for CI at one and three minutes after intubation (P = 0.024 and P = 0.048, respectively), and SVR in five minutes after intubation (P = 0.009), with differences being statistically significant. Conclusions: Both anesthetic regimens were acceptable for induction in patients with coronary artery disease and left ventricular dysfunction undergoing coronary artery bypass graft surgery. PMID:26161330

  3. Impaired neuronal KCC2 function by biallelic SLC12A5 mutations in migrating focal seizures and severe developmental delay

    PubMed Central

    Saitsu, Hirotomo; Watanabe, Miho; Akita, Tenpei; Ohba, Chihiro; Sugai, Kenji; Ong, Winnie Peitee; Shiraishi, Hideaki; Yuasa, Shota; Matsumoto, Hiroshi; Beng, Khoo Teik; Saitoh, Shinji; Miyatake, Satoko; Nakashima, Mitsuko; Miyake, Noriko; Kato, Mitsuhiro; Fukuda, Atsuo; Matsumoto, Naomichi

    2016-01-01

    Epilepsy of infancy with migrating focal seizures (EIMFS) is one of the early-onset epileptic syndromes characterized by migrating polymorphous focal seizures. Whole exome sequencing (WES) in ten sporadic and one familial case of EIMFS revealed compound heterozygous SLC12A5 (encoding the neuronal K+-Cl− co-transporter KCC2) mutations in two families: c.279 + 1G > C causing skipping of exon 3 in the transcript (p.E50_Q93del) and c.572 C >T (p.A191V) in individuals 1 and 2, and c.967T > C (p.S323P) and c.1243 A > G (p.M415V) in individual 3. Another patient (individual 4) with migrating multifocal seizures and compound heterozygous mutations [c.953G > C (p.W318S) and c.2242_2244del (p.S748del)] was identified by searching WES data from 526 patients and SLC12A5-targeted resequencing data from 141 patients with infantile epilepsy. Gramicidin-perforated patch-clamp analysis demonstrated strongly suppressed Cl− extrusion function of E50_Q93del and M415V mutants, with mildly impaired function of A191V and S323P mutants. Cell surface expression levels of these KCC2 mutants were similar to wildtype KCC2. Heterologous expression of two KCC2 mutants, mimicking the patient status, produced a significantly greater intracellular Cl− level than with wildtype KCC2, but less than without KCC2. These data clearly demonstrated that partially disrupted neuronal Cl− extrusion, mediated by two types of differentially impaired KCC2 mutant in an individual, causes EIMFS. PMID:27436767

  4. Delayed Reconstruction by Total Calcaneal Allograft following Calcanectomy: Is It an Option?

    PubMed Central

    Degeorge, Benjamin; Forget, David; Gaillard, Florent; Canovas, François

    2016-01-01

    Many options are available in literature for the management of delayed reconstruction following calcanectomy. In cases of low-grade tumor lesions, conservative surgery can be considered. We describe a case of delayed reconstruction by calcaneal allograft after calcanectomy for low-grade chondrosarcoma. At 12-month follow-up, the patient had no pain; MSTS score and AOFAS score were satisfactory. Subtalar nonunion was observed with no secondary displacement or graft necrosis. The aim of conservative treatment for this patient was to restore normal gait with plantigrade locomotion and function of the Achilles tendon. Calcaneal reconstruction by total allograft is an alternative approach following calcanectomy for calcaneal tumors. We also discussed other options of calcaneal reconstruction. PMID:27990308

  5. Polyacrylamide grafting of modified graphene oxides by in situ free radical polymerization

    SciTech Connect

    Tang, Mingyi; Xu, Xiaoyang; Wu, Tao; Zhang, Sai; Li, Xianxian; Li, Yi

    2014-12-15

    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-ray 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.

  6. Skin graft - slideshow

    MedlinePlus

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

  7. Acrylonitrile grafted to PVDF

    SciTech Connect

    Yang, Jin; Eitouni, Hany Basam

    2015-03-31

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

  8. Grafting for disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Grafting for disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Application of cerium nitrate-silver sulphadiazine allows for postponement of excision and grafting.

    PubMed

    Vehmeyer-Heeman, M; Tondu, T; Van den Kerckhove, E; Boeckx, W

    2006-02-01

    Early excision and grafting cannot always be performed due to patient's medical status, and the lack of adequate donor sites. The use of cerium nitrate-silver sulphadiazine cream, which causes the formation of a leather-like eschar with excellent resistance to infection, is an alternative method. In order to postpone operations by using cerium nitrate-silver sulphadiazine, we compared the differences in contamination of the grafted areas between early and delayed excision. Eighteen patients underwent excision and grafting within 5 days post burn and nineteen patients were surgically treated after 5 days. Twelve months later the grafted areas were evaluated. Contamination of the grafted area occurred in 17 patients. No differences in contamination occurred between the early and delayed excision group, 8 versus 9. Also no differences in type of organism cultured and follow-up results were found between the early and delayed excision group. Cerium nitrate-silver sulphadiazine allows surgical treatment to be delayed without an increase of contamination of the grafted area and does not adversely affect the long-term outcome.

  11. Contingencies promote delay tolerance.

    PubMed

    Ghaemmaghami, Mahshid; Hanley, Gregory P; Jessel, Joshua

    2016-09-01

    The effectiveness of functional communication training as treatment for problem behavior depends on the extent to which treatment can be extended to typical environments that include unavoidable and unpredictable reinforcement delays. Time-based progressive delay (TBPD) often results in the loss of acquired communication responses and the resurgence of problem behavior, whereas contingency-based progressive delay (CBPD) appears to be effective for increasing tolerance for delayed reinforcement. No direct comparison of TBPD and CBPD has, however, been conducted. We used single-subject designs to compare the relative efficacy of TBPD and CBPD. Four individuals who engaged in problem behavior (e.g., aggression, vocal and motor disruptions, self-injury) participated. Results were consistent across all participants, and showed lower rates of problem behavior and collateral responses during CBPD than during TBPD. The generality of CBPD treatment effects, including optimal rates of communication and compliance with demands, was demonstrated across a small but heterogeneous group of participants, reinforcement contingencies, and contexts.

  12. Delayed administration of the nucleic acid analog 2Cl-C.OXT-A attenuates brain damage and enhances functional recovery after ischemic stroke.

    PubMed

    Okabe, Naohiko; Nakamura, Emi; Himi, Naoyuki; Narita, Kazuhiko; Tsukamoto, Ikuko; Maruyama, Tokumi; Sakakibara, Norikazu; Nakamura, Takehiro; Itano, Toshifumi; Miyamoto, Osamu

    2013-04-19

    2Cl-C.OXT-A (COA-Cl) is a novel nucleic acid analog that enhances angiogenesis through extracellular signal-regulated kinase 1 or 2 (ERK1/2) activation. ERK1/2 is a well-known kinase that regulates cell survival, proliferation and differentiation in the central nervous system. We performed in vitro and in vivo experiments to investigate whether COA-Cl can attenuate neuronal damage and enhance recovery after brain ischemia. In primary cortical neuron cultures, COA-Cl prevented neuronal injury after 2h of oxygen-glucose deprivation. COA-Cl increased phospho-ERK levels in a dose-dependent manner and COA-Cl-induced neuroprotection and ERK1/2 activation was inhibited by suramin or PD98059. The effect of COA-Cl was evaluated in vivo with 60min of middle cerebral artery occlusion combined with bilateral common carotid artery occlusion. COA-Cl or saline was injected intracerebroventricularly 5min after reperfusion. COA-Cl significantly reduced infarct volume and improved neurological deficits upon injection of 15 or 30μg/kg COA-Cl. Moreover, COA-Cl reduced the number of TUNEL positive cells in ischemic boundary, while rCBF was not significantly changed by COA-Cl administration. We also evaluated the effect of delayed COA-Cl administration on recovery from brain ischemia by continuous administration of COA-Cl from 1 to 8 days after reperfusion. Delayed continuous COA-Cl administration also reduced infarct volume. Furthermore, COA-Cl enhanced peri-infarct angiogenesis and synaptogenesis, resulting in improved motor function recovery. Our findings demonstrate that COA-Cl exerts both neuroprotective and neurorestorative effects over a broad therapeutic time window, suggesting COA-Cl might be a novel and potent therapeutic agent for ischemic stroke.

  13. [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.

  14. Contingency Tracking during Unsignaled Delayed Reinforcement

    ERIC Educational Resources Information Center

    Keely, Josue; Feola, Tyler; Lattal, Kennon A.

    2007-01-01

    Three experiments were conducted with rats in which responses on one lever (labeled the functional lever) produced reinforcers after an unsignaled delay period that reset with each response during the delay. Responses on a second, nonfunctional, lever did not initiate delays, but, in the first and third experiments, such responses during the last…

  15. UAVs and Control Delays

    DTIC Science & Technology

    2005-09-01

    Transport Delay itI tl2 s2+(tl +t2tI2)s+ 1 Delay Figure 17 A Matlab Simulink model used to compare a simple delayed system , in this case an integrator...23 3 Control of tim e-delay system s...discuss the various sources of delays, leading to an assessment of typical delays to be expected in a few example systems . Sources of delay that will

  16. The versatile autogenous rib graft in septorhinoplasty.

    PubMed

    Sherris, D A; Kern, E B

    1998-01-01

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

  17. 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

  18. [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.

  19. Electrostrictive Graft Elastomers and Applications

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  20. Effect of FTY720 (fingolimod) on graft survival in renal transplant recipients: a systematic review protocol

    PubMed Central

    Gholamnezhadjafari, Reza; Falak, Reza; Aflatoonian, Reza; Ali Keshtkar, Abbas; Rezaei, Abbas

    2016-01-01

    Introduction Studies have shown that FTY720 has inconsistent effects in kidney transplant recipients. Several review articles on FTY720 have been published, but most have focused on the mechanism of action of FTY720. Therefore, this review aims to evaluate and determine the beneficial and harmful effects of FTY720 therapy in kidney transplant recipients. Methods and analysis We electronically searched the following databases: PubMed, Scopus, the Web of Sciences, EMBASE, Cochrane databases and the Cochrane Central Registry of Controlled Trials. Any clinical, randomised controlled trials relating to FTY720 for treating kidney transplant recipients were included without publication status or language restriction. Study selection, data extraction and assessment of study quality were performed independently by two researchers. Data were synthesised by either the fixed effects or the random effects model according to a heterogeneity test. If the extracted data were suitable for meta-analysis, STATA software was used to combine the relative risks for dichotomous outcomes, and the mean differences for continuous outcomes with 95% CIs were measured. Death, loss of function and incidence of acute kidney rejection were assessed as the primary outcomes. Renal graft function, malignancy, delayed graft function and infection were evaluated as secondary outcomes. Ethics/dissemination This review does not require formal ethics approval because the data are not individualised. The resulting review article will be submitted for publication in a peer-reviewed journal. Trial registration number CRD42015024648. PMID:27126975

  1. A randomized controlled trial with bright light and melatonin for the treatment of delayed sleep phase disorder: effects on subjective and objective sleepiness and cognitive function.

    PubMed

    Wilhelmsen-Langeland, Ane; Saxvig, Ingvild W; Pallesen, Ståle; Nordhus, Inger-Hilde; Vedaa, Øystein; Lundervold, Astri J; Bjorvatn, Bjørn

    2013-10-01

    Delayed sleep phase disorder (DSPD) is a circadian rhythm sleep disorder. Patients with DSPD have problems initiating sleep if they go to bed at a conventional time, and they often have problems waking at desired times. If they rise early in the morning, they usually experience severe sleepiness during morning hours. In the present study, we investigated the short- and long-term effects on measures of subjective and objective sleepiness and cognitive function of bright light and melatonin treatment alongside gradually advanced rise times in adolescents and young adults. Four treatment conditions were used in the short-term intervention (2 weeks): dim light (placebo) + placebo capsule, bright light + placebo capsule, dim light (placebo) + melatonin capsule, and bright light + melatonin capsule. This was followed by a long-term intervention (3 months) including 2 conditions: no treatment and combined bright light + melatonin treatment. Effects of treatment on sleepiness and fatigue were the primary outcome measures, and effects on cognitive function were secondary outcome measures. On a gradual advancement of the rise time schedule, all treatment conditions (bright light, melatonin, combination, and placebo) were almost equally effective in improving subjective daytime sleepiness, fatigue, and cognitive function in the 2-week study. The 2-week intervention showed no effect on objective sleepiness. Long-term treatment increased some of the positive effects seen after 2 weeks. The combined bright light and melatonin treatment improved subjective daytime sleepiness, fatigue, and cognitive function in the 3-month study. The no-treatment group returned to baseline values on most variables. In conclusion, a gradual advancement of rise times seems to produce positive effects on subjective sleepiness, fatigue, and cognitive performance during short-term treatment of patients with DSPD. However, the benefits from gradually advanced rise times seem to wear off, suggesting that

  2. Functional outcome of en bloc resection of a giant cell tumour of the distal radius and arthrodesis of the wrist and distal ulna using an ipsilateral double barrel segmental ulna bone graft combined with a modified Sauve-Kapandji procedure.

    PubMed

    Zhang, W; Zhong, J; Li, D; Sun, C; Zhao, H; Gao, Y

    2016-08-25

    Giant cell tumour of the distal radius is a locally aggressive lesion. In this study, we performed a wrist arthrodesis reconstruction with an ipsilateral double barrel segmental ulnar bone graft combined with a modified Sauve-Kapandji procedure for a giant cell tumour of the distal radius. From January 2007 to September 2013, we followed eight patients for a mean duration of 36 months. One patient developed a recurrence and was treated by amputation; the other seven patients achieved radiological union in about 8 months. There was no wrist instability, deformation or dislocation; the mean range of motion of the forearm achieved 75° of supination and 70° of pronation. The patients could recover reasonable grip strength. This new operative procedure can excise the tumour with a low rate of recurrence, fewer functional deficits and fewer complications than reported for other procedures.

  3. Wada property in systems with delay

    NASA Astrophysics Data System (ADS)

    Daza, Alvar; Wagemakers, Alexandre; Sanjuán, Miguel A. F.

    2017-02-01

    Delay differential equations take into account the transmission time of the information. These delayed signals may turn a predictable system into chaotic, with the usual fractalization of the phase space. In this work, we study the connection between delay and unpredictability, in particular we focus on the Wada property in systems with delay. This topological property gives rise to dramatic changes in the final state for small changes in the history functions.

  4. Delayed redo pyeloplasty fails to recover lost renal function after failed pyeloplasty: Early sonographic changes that correlate with a loss of differential renal function

    PubMed Central

    Chung, Doo Yong; Hong, Chang Hee; Im, Young Jae; Lee, Yong Seung; Kim, Sang Woon

    2015-01-01

    Purpose To evaluate changes in differential renal function (DRF), as a functional outcome, in children who underwent redo pyeloplasty for management of failed pyeloplasty and to examine the factors that affect functional outcomes. Materials and Methods Between January 2002 and November 2010, a total of 18 patients who underwent redo pyeloplasty for persistent ureteropelvic junction obstruction after failed pyeloplasty were enrolled in this study. We assessed perioperative factors and evaluated changes in renal cortical thickness (RCT), renal function, and hydronephrosis by use of serial ultrasound and diuretic renography. Results The mean follow-up period was 44.83±28.86 months. After redo pyeloplasty, prevention of further functional deterioration was observed in only 12 of the 18 patients. After dividing the patients according to this observation, we discovered significant differences in both change in DRF (dDRF) and change in RCT (dRCT) (difference between before and after initial pyeloplasty) between the two groups (p<0.001). Additionally, we noted a significant positive correlation between dRCT and dDRF. All patients showed improvements in hydronephrosis grade and relief of symptoms compared with before redo pyeloplasty. Conclusions Redo pyeloplasty should be considered in cases of failed pyeloplasty to preserve renal function and obtain relief from symptoms. If patients show severe deterioration of DRF or a decrease in RCT after initial pyeloplasty, preservation of DRF in these patients after redo pyeloplasty could be difficult. Therefore, redo pyeloplasty should be performed before severe deterioration of DRF or decrease in RCT. PMID:25685304

  5. Delayed fluorescence in photosynthesis.

    PubMed

    Goltsev, Vasilij; Zaharieva, Ivelina; Chernev, Petko; Strasser, Reto J

    2009-01-01

    Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

  6. High resolution digital delay timer

    DOEpatents

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  7. Composite vascular grafts with high cell infiltration by co-electrospinning.

    PubMed

    Tan, Zhikai; Wang, Hongjie; Gao, Xiangkai; Liu, Tong; Tan, Yongjun

    2016-10-01

    There is an increasing demand for functional small-diameter vascular grafts (diameter<6mm) to be used in clinical arterial replacement. An ideal vascular graft should have appropriate biomechanical properties and be biocompatible. Electrospinning has become a popular polymer processing technique for vascular tissue engineering, but the grafts fabricated by electrospinning often have relatively small pores and low porosity, which limit cell infiltration into scaffolds and hinder the regeneration and remodeling of grafts. In the present study, we aimed to develop an efficient method to prepare electrospun composite vascular grafts comprising natural and synthetic materials. We fabricated grafts made of polycaprolactone, gelatin, and polyvinyl alcohol (PVA) by co-electrospinning, and the scaffolds were further functionalized by immobilizing heparin on them. The PVA fibers degraded rapidly in vivo and generated electrospun scaffolds with high porosity, which significantly enhanced cell proliferation and infiltration. The mechanical properties of the grafts are suitable for use in artery replacement. Heparin functionalization of the grafts yielded a good antithrombogenic effect, which was demonstrated in platelet adhesion tests. Moreover, in vitro and in vivo results demonstrated that the heparin release from the grafts enhanced the growth of endothelial cells, which is important for the endothelium of implanted grafts. The results of this study indicate that our method is effective and controllable for the fabrication of vascular grafts that meet the clinical requirements for blood vessel transplantation.

  8. Genome-wide identification and comparative analysis of grafting-responsive mRNA in watermelon grafted onto bottle gourd and squash rootstocks by high-throughput sequencing.

    PubMed

    Liu, Na; Yang, Jinghua; Fu, Xinxing; Zhang, Li; Tang, Kai; Guy, Kateta Malangisha; Hu, Zhongyuan; Guo, Shaogui; Xu, Yong; Zhang, Mingfang

    2016-04-01

    Grafting is an important agricultural technique widely used to improve plant growth, yield, and adaptation to either biotic or abiotic stresses. However, the molecular mechanisms underlying grafting-induced physiological processes remain unclear. Watermelon (Citrullus lanatus L.) is an important horticultural crop worldwide. Grafting technique is commonly used in watermelon production for improving its tolerance to stresses, especially to the soil-borne fusarium wilt disease. In the present study, we used high-throughput sequencing to perform a genome-wide transcript analysis of scions from watermelon grafted onto bottle gourd and squash rootstocks. Our transcriptome and digital gene expression (DGE) profiling data provided insights into the molecular aspects of gene regulation in grafted watermelon. Compared with self-grafted watermelon, there were 787 and 3485 genes differentially expressed in watermelon grafted onto bottle gourd and squash rootstocks, respectively. These genes were associated with primary and secondary metabolism, hormone signaling, transcription factors, transporters, and response to stimuli. Grafting led to changes in expression of these genes, suggesting that they may play important roles in mediating the physiological processes of grafted seedlings. The potential roles of the grafting-responsive mRNAs in diverse biological and metabolic processes were discussed. Obviously, the data obtained in this study provide an excellent resource for unraveling the mechanisms of candidate genes function in diverse biological processes and in environmental adaptation in a graft system.

  9. β-cyclodextrin functionalized poly (5-amidoisophthalicacid) grafted Fe3O4 magnetic nanoparticles: A novel biocompatible nanocomposite for targeted docetaxel delivery

    NASA Astrophysics Data System (ADS)

    Tarasi, Roghayeh; Khoobi, Mehdi; Niknejad, Hassan; Ramazani, Ali; Ma'mani, Leila; Bahadorikhalili, Saeed; Shafiee, Abbas

    2016-11-01

    Thiol-lactam initiated radical polymerization (TLIRP) was successfully employed to prepare poly-N-5-acrylamidoisophthalicacid grafted onto Fe3O4 magnetic nanoparticles (MNPs@PAIP). β-Cyclodextrin (CD) was then conjugated to the carboxylic groups of the prepared MNPs via carbodiimide activation. Subsequently, tumor-targeting folic acid (FA) was attached to the hydroxyl groups of CD on the surface of the latter MNPs to increase the site-specific intracellular delivery. The prepared MNPs were fully characterized by FTIR, VSM, TGA, XRD, FE-SEM and TEM. Docetaxel (DTX) as hydrophobic anticancer drug was loaded via host-guest inclusion complexation with CD and the release profile of the system was studied at different pH. The effect of MNPs on the cell viability was evaluated for the human embryonic kidney normal cell line (HEK293) as well as HeLa and MDA-MB-231 cancerous cell lines and the results did not show any apparent cytotoxic effect. In comparison, DTX loaded MNPs reduced the growth of HeLa and MDA-MB-231 cells more than free DTX. Intracellular uptake ability of DTX loaded MNPs was also studied using fluorescent microscopy and showed cellular uptake about 90% after 4 h treatment.

  10. A Radio-telemetric System to Monitor Cardiovascular Function in Rats with Spinal Cord Transection and Embryonic Neural Stem Cell Grafts

    PubMed Central

    Hou, Shaoping; Blesch, Armin; Lu, Paul

    2014-01-01

    High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter connected to a radio transmitter into the femoral artery of rats that underwent a T4 spinal cord transection with or without grafting of embryonic brainstem-derived neural stem cells expressing green fluorescent protein. Compared to other methods such as cannula insertion or tail-cuff, telemetry is advantageous to continuously monitor blood pressure and heart rate in freely moving animals. It is also capable of long term multiple data acquisitions. In spinal cord injured rats, basal cardiovascular data under unrestrained condition and autonomic dysreflexia in response to colorectal distension were successfully recorded. In addition, cardiovascular parameters before and after SCI can be compared in the same rat if a transmitter is implanted before a spinal cord transection. One limitation of the described telemetry procedure is that implantation in the femoral artery may influence the blood supply to the ipsilateral hindlimb. PMID:25350486

  11. Quality of Life is Improved and Kidney Function Preserved in Patients with Nephropathic Cystinosis Treated for 2 Years with Delayed-Release Cysteamine Bitartrate

    PubMed Central

    Langman, Craig B.; Greenbaum, Larry A.; Grimm, Paul; Sarwal, Minnie; Niaudet, Patrick; Deschenes, Georges; Cornelissen, Elisabeth A. M.; Morin, Denis; Cochat, Pierre; Elenberg, Ewa; Hanna, Christian; Gaillard, Segolene; Bagger, Mary Jo; Rioux, Patrice

    2014-01-01

    Objectives To determine the long-term effects of delayed-release cysteamine bitartrate (DR-CYS) based on our previous work that established the short-term noninferiority of DR-CYS every 12 hours compared with immediate-release cysteamine bitartrate every 6 hours. Study design We conducted a prospective, controlled, open label, single-arm study of DR-CYS for 2 years in 40 patients to assess efficacy in depletion of cystine in peripheral white blood cells, to assess the dose required to maintain white blood cell content of cystine <1 nmol ½ cystine/mg protein, to measure quality of life using the Pediatric Quality of Life Inventory, change in estimated glomerular filtration rate, and change in height Z-score. Results Through 24 months of study, the mean white blood cell content of cystine was always <1 nmol ½ cystine/mg protein, and the dose of DR-CYS decreased from 43.5-40.1 mg/kg/d (P = .05), and the significant improvement in social function, school function, and in total function scores on the Pediatric Quality of Life Inventory remained. The estimated glomerular filtration rate was maintained and growth velocity was maintained at 24 months compared with the baseline height Z-score. Conclusions The use of a DR-CYS administered every 12 hours to patients with cystinosis is of great benefit to their quality of life and to important biomarkers of disease control, when studied in a prospective, controlled fashion. We suggest that DR-CYS should be considered for substrate depletion in patients with cystinosis. PMID:24948347

  12. [Diagnosis of delayed puberty].

    PubMed

    Busiah, K; Belien, V; Dallot, N; Fila, M; Guilbert, J; Harroche, A; Leger, J

    2007-09-01

    Puberty is the phenomenon that conducts once to reproductive maturation. Delayed puberty (DP) is defined by the absence of testicular development in boys beyond 14 years old (or a testicular volume lower than 4 ml) and by the absence of breast development in girls beyond 13 years old. DP occurs in approximatively 3% of cases. Most cases are functional DP, with a large amount of constitutional delay of puberty. Others etiologies are hypogonadotrophic hypogonadism like Kallmann syndrome, or hypergonadotrophic hypogonadism. Turner syndrome is a diagnostic one should not forget by its frequency. Treatment is hormonal replacement therapy and of the etiology. During the last decade, many genes have been identified and elucidated the etiological diagnosis of some hypogonadotrophic hypogonadism syndrome. Further studies are required in collaboration with molecular biologists to better understand the mechanism of hypothalamic pituitary gonadal axis abnormalities and of the neuroendocrine physiology of the onset of puberty.