WorldWideScience

Sample records for end-to-side side-to-side grafting

  1. Flow and wall shear stress in end-to-side and side-to-side anastomosis of venous coronary artery bypass grafts

    Poulikakos Dimos

    2007-09-01

    Full Text Available Abstract Purpose Coronary artery bypass graft (CABG surgery represents the standard treatment of advanced coronary artery disease. Two major types of anastomosis exist to connect the graft to the coronary artery, i.e., by using an end-to-side or a side-to-side anastomosis. There is still controversy because of the differences in the patency rates of the two types of anastomosis. The purpose of this paper is to non-invasively quantify hemodynamic parameters, such as mass flow and wall shear stress (WSS, in end-to-side and side-to-side anastomoses of patients with CABG using computational fluid dynamics (CFD. Methods One patient with saphenous CABG and end-to-side anastomosis and one patient with saphenous CABG and side-to-side anastomosis underwent 16-detector row computed tomography (CT. Geometric models of coronary arteries and bypasses were reconstructed for CFD analysis. Blood flow was considered pulsatile, laminar, incompressible and Newtonian. Peri-anastomotic mass flow and WSS were quantified and flow patterns visualized. Results CFD analysis based on in-vivo CT coronary angiography data was feasible in both patients. For both types of CABG, flow patterns were characterized by a retrograde flow into the native coronary artery. WSS variations were found in both anastomoses types, with highest WSS values at the heel and lowest WSS values at the floor of the end-to-side anastomosis. In contrast, the highest WSS values of the side-to-side anastomosis configuration were found in stenotic vessel segments and not in the close vicinity of the anastomosis. Flow stagnation zones were found in end-to-side but not in side-to-side anastomosis, the latter also demonstrating a smoother stream division throughout the cardiac cycle. Conclusion CFD analysis of venous CABG based on in-vivo CT datasets in patients was feasible producing qualitative and quantitative information on mass flow and WSS. Differences were found between the two types of anastomosis

  2. Long-term follow-up of treatment of erectile dysfunction after radical prostatectomy using nerve grafts and end-to-side somatic-autonomic neurorraphy: a new technique.

    Souza Trindade, José Carlos; Viterbo, Fausto; Petean Trindade, André; Fávaro, Wagner José; Trindade-Filho, José Carlos Souza

    2017-06-01

    To study a novel penile reinnervation technique using four sural nerve grafts and end-to-side neurorraphies connecting bilaterally the femoral nerve and the cavernous corpus and the femoral nerve and the dorsal penile nerves. Ten patients (mean [± sd; range] age 60.3 [± 4.8; 54-68] years), who had undergone radical prostatectomy (RP) at least 2 years previously, underwent penile reinnervation in the present study. Four patients had undergone radiotherapy after RP. All patients reported satisfactory sexual activity prior to RP. The surgery involved bridging of the femoral nerve to the dorsal nerve of the penis and the inner part of the corpus cavernosum with sural nerve grafts and end-to-side neurorraphies. Patients were evaluated using the International Index of Erectile Function (IIEF) questionnaire and pharmaco-penile Doppler ultrasonography (PPDU) preoperatively and at 6, 12 and 18 months postoperatively, and using a Clinical Evolution of Erectile Function (CEEF) questionnaire, administered after 36 months. The IIEF scores showed improvements with regard to erectile dysfunction (ED), satisfaction with intercourse and general satisfaction. Evaluation of PPDU velocities did not reveal any difference between the right and left sides or among the different time points. The introduction of nerve grafts neither caused fibrosis of the corpus cavernosum, nor reduced penile vascular flow. CEEF results showed that sexual intercourse began after a mean of 13.7 months with frequency of sexual intercourse varying from once daily to once monthly. Acute complications were minimal. The study was limited by the small number of cases. A total of 60% of patients were able to achieve full penetration, on average, 13 months after reinnervation surgery. Patients previously submitted to radiotherapy had slower return of erectile function. We conclude that penile reinnervation surgery is a viable technique, with effective results, and could offer a new treatment method for ED after

  3. The side-to-side fashion for individual distal coronary anastomosis using venous conduit.

    Kato, Takayoshi; Tsunekawa, Tomohiro; Motoji, Yusuke; Hirakawa, Akihiro; Okawa, Yasuhide; Tomita, Shinji

    2017-04-01

    Regarding to coronary artery bypass grafting (CABG), the end-to-side anastomosis (ESA) has been performed as a gold standard. Recently, the effectiveness of the distal side-to-side anastomosis (SSA) in CABG using internal mammary artery has been reported. The benefit of SSA comparing to ESA also has been disclosed by computing simulation. However, use of SSA by venous conduit for individual CABG has not been reported. In this study, we investigated feasibility of SSA. From January 2013 to October 2014, we conducted 114 CABGs. There were 92 venous distal anastomoses without sequential anastomotic site (61 SSA and 31 ESA). The anastomosis was evaluated before discharge and at 1 year after the procedure by angiography or multi-detector row computed tomographic coronary angiography. The median values for time to anastomosis were 13 min in the two group (p = 0.89). There was no revision of anastomosis in both groups. Additional stitches for hemostasis were required significantly less in SSA than ESA (18.0 vs 45.2 %, respectively, p fashion is easy to perform and maybe beneficial in blood flow pattern.

  4. Side-to-side sutureless vascular anastomosis with magnets.

    Erdmann, Detlev; Sweis, Ranya; Heitmann, Christoph; Yasui, Koji; Olbrich, Kevin C; Levin, L Scott; Sharkawy, A Adam; Klitzman, Bruce

    2004-09-01

    Abbe and Payr introduced vascular techniques and devices to facilitate vessel anastomosis over a century ago. Obora published the idea of a sutureless vascular anastomosis with use of magnetic rings in 1978. The purpose of this study was to assess the performance of a new magnetic device to perform a side-to-side arteriovenous anastomosis in a dog model. Male fox hounds (25 kg) were treated preoperatively and daily postoperatively with clopidogrel bisulfate (Plavix) and aspirin. The femoral artery and vein were exposed unilaterally in 3 dogs and bilaterally in 4 dogs (n = 11 anastomoses). A 4-mm arteriotomy was performed, and 1 oval magnet 0.5 mm thick was inserted into the lumen of the artery and a second magnet was applied external to the artery, compressing and stabilizing the arterial wall to create a magnetic port. An identical venous magnetic port was created with another pair of oval magnets. When the 2 ports were allowed to approach each other, they self-aligned and magnetically coupled to complete the arteriovenous anastomosis. Patency was assessed for the first hour with direct observation, again after 9 weeks with duplex ultrasound scanning, and at 10 weeks under direct open observation. The anastomoses were explanted after 10 weeks. Hydrodynamic resistance was measured ex vivo on the final 8 anastomoses by measuring the pressure drop across an anastomosis with a known flow rate. After implantation, very high flow created visible turbulence and palpable vibration. All 11 anastomoses were patent under direct observation and palpation. Ten of 11 anastomoses were clearly patent on duplex scans, and patency of 1 anastomosis was questionable. Hydrodynamic resistance averaged 0.73 +/- 0.33 mm Hg min/mL (mean +/- SEM). Vascular anastomoses performed with magnets demonstrated feasibility; exhibited 100% patency after 10 weeks in a dog arteriovenous shunt model; lacked apparent aneurysm or other potentially catastrophic failure; demonstrated remodeling of the

  5. Muscle reinnervation in one or two stages?: experimental study in rats with end-to-side nerve graft Reinervação muscular em um ou dois estágios?: estudo experimental em ratos com enxerto de nervo término-lateral

    Joseli Assem Bersaneti

    2012-12-01

    Full Text Available PURPOSE: To compare muscle reinnervation in one and two surgical stages using end-to-side neurorrhaphy (ESN without donor nerve injury. METHODS: The experiment was performed on four groups of 20 rats. Group 1 (G1, one stage, received the graft which was sutured to the tibial nerve, with ESN, and its free stump was sutured end-to-end to the distal stump of the sectioned peroneal nerve (PN, all in the same operation. In Group 2 (G2, two stages, the nerve graft was sutured to the tibial nerve, with ESN. Two months later the PN was sectioned and its distal stump connected to the distal stump of the graft as in G1. Normal control group (Gn received the graft only sutured to the tibial nerve, with ESN. Denervated control group (Gd, as well received the graft and had the PN sectioned and its two stumps buried in adjacent musculature, with the aim of denervating the cranial tibial muscle (CTM, the target of this study. The parameters used to evaluate CTM reinnervation were muscle mass, muscle fiber's minimum diameter and area. RESULTS: The mean CTM mass, the average of the muscular fibers areas and the average of the muscular fiber minimum diameters was higher (all pOBJETIVO: Comparar a reinervação muscular com enxerto de nervo em um e dois tempos operatórios, utilizando a neurorrafia término-lateral (NTL sem lesão do nervo doador. MÉTODOS: Vinte ratos foram distribuídos em quatro grupos. O grupo 1 (G1, um estágio, recebeu o enxerto que foi suturado ao nervo tibial (NT, por meio de NTL, e seu coto livre foi suturado por NTL ao coto distal do nervo peroneal (NP, seccionado a um centímetro do NT, na mesma cirurgia. O grupo 2 (G2, dois estágios, recebeu o enxerto de nervo na primeira cirurgia, como já descrito. Dois meses depois, na segunda cirurgia, o NP foi seccionado e seu coto distal ligado ao coto distal do enxerto como em G1. O grupo controle de normalidade (Gn recebeu o enxerto da mesma forma, apenas. E o grupo controle de denerva

  6. [Treatment of painful neuromas via end-to-side neurorraphy].

    Aszmann, O C; Moser, V; Frey, M

    2010-08-01

    Management of the painful neuroma has been subject to controversy since the earliest descriptions of this disabling problem. Today, treatment is limited to resection of the neuroma and implantation of the nerve in a muscle at a location where it is safe from irritation and trauma. This however is not attainable in many cases and it is our clinical experience, that nerves without a target remain a source of constant discomfort and pain. Recently we reported of the feasibility of neuroma prevention through end-to-side neurorraphy into adjacent sensory and/or motor nerves to provide a target for axons deprived of their endorgan. Here we report of our first clinical experience with this method in sixteen patients with longstanding upper and lower extremity neuromas. 16 patients were included in this study. All had neuromas of different sensory nerves of both the upper and lower extremity. 11 were of iatrogenic origin, 5 were caused by different traumas. 8 had previous attempts to surgically treat the neuroma. Finally, all were treated by end-to-side neurorraphy into adjacent nerves. Postoperatively quantitative sensorymotor testing was performed to evaluate possible changes of nerve function of the recipient nerves. Pain was evaluated by visual analogue score and changes in pain medication. In no patient a sensory or motor deficit or painful sensations were induced in the target area of the recipient nerve. Some had dysaesthesias for about 6 months, which finally subsided. All but 1 patient improved in their symptoms at a follow-up of more than 2 years. Previous experimental work and present clinical results suggest that axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented without inducing sensory or motor dysfunctions in the recipient nerve. Georg Thieme Verlag KG Stuttgart New York.

  7. Computational fluid dynamic evaluation of the side-to-side anastomosis for arteriovenous fistula.

    Hull, Jeffrey E; Balakin, Boris V; Kellerman, Brad M; Wrolstad, David K

    2013-07-01

    The goal of this research was to compare side-to-side (STS) and end-to-side (ETS) anastomoses in a computer model of the arteriovenous fistula with computational fluid dynamic analysis. A matrix of 17 computer arteriovenous fistula models (SolidWorks, Dassault Systèmes, France) of artery-vein pairs (3-mm-diameter artery + 3-mm-diameter vein and 4-mm-diameter artery +6-mm-diameter vein elliptical anastomoses) in STS, 45° ETS, and 90° ETS configurations with cross-sectional areas (CSAs) of 3.5 to 18.8 mm(2) were evaluated with computational fluid dynamic software (STAR-CCM+; CD-adapco, Melville, NY) in simulations at defined flow rates from 600 to 1200 mL/min and mean arterial pressures of 50 to 140 mm Hg. Models and configurations were evaluated for pressure drop across the anastomosis, arterial inflow, venous outflow, arterial outflow, velocity vector, and wall shear stress (WSS) profile. Pressure drop across the anastomosis was inversely proportional to anastomotic CSA and to venous outflow and was proportional to arterial inflow. Pressure drop was greater in 3 + 3 models than in 4 + 6 STS models; 90° ETS configurations had the lowest pressure drops and were nearly identical, whereas 45° ETS configurations had the highest pressure drops. Venous outflow in the 4 + 6 model in STS configurations, evaluated at 100 mm Hg arterial inflow pressure, was 390, 592, 610, and 886 mL/min in anastomotic CSAs of 3.5, 5.3, 7.1, and 18.8 mm(2), respectively, and was similar in 90° ETS (609 and 908 mL/min) and lower in 45° ETS (534 and 562 mL/min) configurations at CSAs of 5.3 and 18.8 mm(2). The mean increase in venous outflow was 69 mL/min (range, -59 to 134) between 3 + 3 and 4 + 6 models at 100 mm Hg arterial inflow. The most uniform WSS profile occurs in STS anastomoses followed by 45° ETS and then 90° ETS anastomoses. The STS and 90° ETS anastomoses have high venous outflow and a tendency toward reversed arterial outflow. The 45° ETS anastomosis has reduced venous

  8. End-to-side neurorrhaphy with and without perineurium

    Fausto Viterbo

    Full Text Available OBJECTIVE: We compared end-to-side neurorraphy with and without the perineural sheath. METHOD: Twenty rats were used. The peroneal nerve was sectioned and the distal end was sutured to the lateral face of the tibial nerve. We removed the perineural sheath only on the right side, but not on the left side. The proximal end of the peroneal nerve was curved back approximately at a 100° angle and implanted into the adductor muscle. Six months later, the 14 surviving animals were submitted to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. RESULTS: On the right side, the muscles that had positive response needed an average of 258.89 mV (±92.31 of electric stimulus and on the left side 298.34 mV (±139.32. The average weight of the tibial cranial muscles of the right side was 0.47 g (0.18 and for the left side 0.45 g (0.15. The distal end of the peroneal nerve showed averages of 310.29 (±191.34 nerve fibers on the right side and 287.71 (±183.60 on the left side. The tibial nerve above the neurorraphy showed averages of 939.46 (±223.51 nerve fibers on the right side and 959.46 (±327.48 on the left side. The tibial nerve below the neurorraphy showed averages of 935.17 (±298.65 nerve fibers on the right side and 755.31 (±323.26 on the left side. The average areas of the right tibial cranial muscles were 0.0162 m2 (±0.008, after 230 magnification, and 0.0152 m2 (0.0064 for the left tibial cranial muscles. The histological features of the tibial cranial muscles, taking normal as 100%, were 78.21 (±20.75 on the right side and 82.14 (±15.89 on the left side. The statistical analysis (Student's t test did not reveal any difference (p>0.05 among right and left sides for all variables. CONCLUSION: The authors concluded that the two neurorraphies (with and without perineurium did not show any difference regarding morphological and electrophysiological features studied.

  9. End-to-side neurorrhaphy with and without perineurium.

    Viterbo, F; Teixeira, E; Hoshino, K; Padovani, C R

    1998-01-01

    We compared end-to-side neurorraphy with and without the perineural sheath. Twenty rats were used. The peroneal nerve was sectioned and the distal end was sutured to the lateral face of the tibial nerve. We removed the perineural sheath only on the right side, but not on the left side. The proximal end of the peroneal nerve was curved back approximately at a 100 degrees angle and implanted into the adductor muscle. Six months later, the 14 surviving animals were submitted to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. On the right side, the muscles that had positive response needed an average of 258.89 mV (+/- 92.31) of electric stimulus and on the left side 298.34 mV (+/- 139.32). The average weight of the tibial cranial muscles of the right side was 0.47 g (0.18) and for the left side 0.45 g (0.15). The distal end of the peroneal nerve showed averages of 310.29 (+/- 191.34) nerve fibers on the right side and 287.71 (+/- 183.60) on the left side. The tibial nerve above the neurorraphy showed averages of 939.46 (+/- 223.51) nerve fibers on the right side and 959.46 (+/- 327.48) on the left side. The tibial nerve below the neurorraphy showed averages of 935.17 (+/- 298.65) nerve fibers on the right side and 755.31 (+/- 323.26) on the left side. The average areas of the right tibial cranial muscles were 0.0162 m2 (+/- 0.008), after 230 magnification, and 0.0152 m2 (0.0064) for the left tibial cranial muscles. The histological features of the tibial cranial muscles, taking normal as 100%, were 78.21 (+/- 20.75) on the right side and 82.14 (+/- 15.89) on the left side. The statistical analysis (Student's t test) did not reveal any difference (p > 0.05) among right and left sides for all variables. The authors concluded that the two neurorraphies (with and without perineurium) did not show any difference regarding morphological and electrophysiological features studied.

  10. Experimental research on end-to-side anastomosis of peripheral nerves and effect of FK506 on end-to-side anastomosis.

    Yang, L M; Wu, Y X; Zhang, X P; Li, X H

    2014-01-01

    To study the effects of end-to-side anastomosis of initially-denatured nerves at different times. 60 male Wistar albino rats were used to fabricate animal models for the experiment on end-to-side anastomosis of peripheral nerves and 50 female Wistar albino rats were used to fabricate animal models for the experiment on the effect of FK506 on end-to-side anastomosis. Bilateral common peroneal nerve, tibialis anterior muscle electrophysiological and histological examinations, tibialis anterior muscle wet muscle weight determination, and motor end plate examination were performed 3 months after operation. All recovery rates of action potential, single muscle contraction force and tetanic contraction force of the FK506 experimental group are significantly higher than those of the control group and the sectional area of muscle fiber is also higher than that of the control group of normal saline. The best time for end-to-side anastomosis of nerves should be controlled within 2 weeks and the effect of end-to-side anastomosis of nerves will gradually become unsatisfactory. FK506 plays a role in promoting functional rehabilitation following nerve end-to-side anastomosis (Tab. 7, Fig. 4, Ref. 31).

  11. Laparoscopic side-to-side pancreaticojejunostomy for chronic pancreatitis in children

    Kyoichi Deie

    2016-01-01

    Full Text Available Surgical pancreatic duct (PD drainage for chronic pancreatitis in children is relatively rare. It is indicated in cases of recurrent pancreatitis and PD dilatation that have not responded to medical therapy and therapeutic endoscopy. We performed laparoscopic side-to-side pancreaticojejunostomy for two paediatric patients with chronic pancreatitis. The main PD was opened easily by electrocautery after locating the dilated PD by intraoperative ultrasonography. The dilated PD was split longitudinally from the pancreatic tail to the pancreatic head by laparoscopic coagulation shears or electrocautery after pancreatography. A laparoscopic side-to-side pancreaticojejunostomy was performed by a one-layered technique using continuous 4-0 polydioxanone (PDS sutures from the pancreatic tail to the pancreatic head. There were no intraoperative or postoperative complications or recurrences. This procedure has cosmetic advantages compared with open surgery for chronic pancreatitis. Laparoscopic side-to-side pancreaticojejunostomy in children is feasible and effective for the treatment of chronic pancreatitis.

  12. Better long-term outcomes with hilar ductoplasty and a side-to-side Roux-en-Y hepaticojejunostomy.

    Xia, Hong-Tian; Liu, Yang; Yang, Tao; Liang, Bin; Wang, Jing; Dong, Jia-Hong

    2017-07-01

    Whether a wide hilar hepaticojejunostomy after bile duct cyst (BDC) excision can prevent the development of postoperative complications remains an unanswered question. We compared our outcomes after a minimum of 2-y follow-up in patients with Todani type Ia choledochal cyst treated with hilar ductoplasty followed by a side-to-side Roux-en-Y hepaticojejunostomy (ductoplasty group) or radical cyst resection with an end-to-side Roux-en-Y hepaticojejunostomy (conventional group). We retrospectively reviewed the records of patients with Todani type Ia choledochal cyst who received radical cyst excision from January 1997 to December 2012, and we compared the groups' postoperative complications and surgical outcomes. The groups' baseline demographics were similar, except for age. The gender distribution and preoperative presenting symptoms were comparable in the ductoplasty (n = 72) and conventional (n = 53) groups (all P > 0.05). Average age was 37.0 y for the ductoplasty group and 41.8 y for the conventional group (P = 0.024). The short-term complication rate of the groups was not significantly different (conventional group, 13.2% [7/53]; ductoplasty group, 8.3% [6/72]; all P > 0.05). A significant between-group difference was found in the long-term complication rate of biliary-enteric anastomotic strictures (9.4% in the conventional group and 0% in the ductoplasty group, P = 0.012). The rates of satisfactory surgical outcomes were 91.1% and 77.1% in the ductoplasty and conventional groups, respectively (P = 0.036). The application of hilar ductoplasty with a side-to-side Roux-en-Y hepaticojejunostomy as the primary surgery for bile duct cyst excision significantly reduced the postoperative complication of biliary-enteric anastomotic stricture and greatly improved our patients' prognosis with regard to biliary function. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Hypoglossal-facial nerve "side"-to-side neurorrhaphy for facial paralysis resulting from closed temporal bone fractures.

    Su, Diya; Li, Dezhi; Wang, Shiwei; Qiao, Hui; Li, Ping; Wang, Binbin; Wan, Hong; Schumacher, Michael; Liu, Song

    2018-06-06

    Closed temporal bone fractures due to cranial trauma often result in facial nerve injury, frequently inducing incomplete facial paralysis. Conventional hypoglossal-facial nerve end-to-end neurorrhaphy may not be suitable for these injuries because sacrifice of the lesioned facial nerve for neurorrhaphy destroys the remnant axons and/or potential spontaneous innervation. we modified the classical method by hypoglossal-facial nerve "side"-to-side neurorrhaphy using an interpositional predegenerated nerve graft to treat these injuries. Five patients who experienced facial paralysis resulting from closed temporal bone fractures due to cranial trauma were treated with the "side"-to-side neurorrhaphy. An additional 4 patients did not receive the neurorrhaphy and served as controls. Before treatment, all patients had suffered House-Brackmann (H-B) grade V or VI facial paralysis for a mean of 5 months. During the 12-30 months of follow-up period, no further detectable deficits were observed, but an improvement in facial nerve function was evidenced over time in the 5 neurorrhaphy-treated patients. At the end of follow-up, the improved facial function reached H-B grade II in 3, grade III in 1 and grade IV in 1 of the 5 patients, consistent with the electrophysiological examinations. In the control group, two patients showed slightly spontaneous innervation with facial function improved from H-B grade VI to V, and the other patients remained unchanged at H-B grade V or VI. We concluded that the hypoglossal-facial nerve "side"-to-side neurorrhaphy can preserve the injured facial nerve and is suitable for treating significant incomplete facial paralysis resulting from closed temporal bone fractures, providing an evident beneficial effect. Moreover, this treatment may be performed earlier after the onset of facial paralysis in order to reduce the unfavorable changes to the injured facial nerve and atrophy of its target muscles due to long-term denervation and allow axonal

  14. End-to-side neurorrhaphy repairs peripheral nerve injury: sensory nerve induces motor nerve regeneration.

    Yu, Qing; Zhang, She-Hong; Wang, Tao; Peng, Feng; Han, Dong; Gu, Yu-Dong

    2017-10-01

    End-to-side neurorrhaphy is an option in the treatment of the long segment defects of a nerve. It involves suturing the distal stump of the disconnected nerve (recipient nerve) to the side of the intimate adjacent nerve (donor nerve). However, the motor-sensory specificity after end-to-side neurorrhaphy remains unclear. This study sought to evaluate whether cutaneous sensory nerve regeneration induces motor nerves after end-to-side neurorrhaphy. Thirty rats were randomized into three groups: (1) end-to-side neurorrhaphy using the ulnar nerve (mixed sensory and motor) as the donor nerve and the cutaneous antebrachii medialis nerve as the recipient nerve; (2) the sham group: ulnar nerve and cutaneous antebrachii medialis nerve were just exposed; and (3) the transected nerve group: cutaneous antebrachii medialis nerve was transected and the stumps were turned over and tied. At 5 months, acetylcholinesterase staining results showed that 34% ± 16% of the myelinated axons were stained in the end-to-side group, and none of the myelinated axons were stained in either the sham or transected nerve groups. Retrograde fluorescent tracing of spinal motor neurons and dorsal root ganglion showed the proportion of motor neurons from the cutaneous antebrachii medialis nerve of the end-to-side group was 21% ± 5%. In contrast, no motor neurons from the cutaneous antebrachii medialis nerve of the sham group and transected nerve group were found in the spinal cord segment. These results confirmed that motor neuron regeneration occurred after cutaneous nerve end-to-side neurorrhaphy.

  15. Side-To-Side Nerve Bridges Support Donor Axon Regeneration Into Chronically Denervated Nerves and Are Associated With Characteristic Changes in Schwann Cell Phenotype.

    Hendry, J Michael; Alvarez-Veronesi, M Cecilia; Snyder-Warwick, Alison; Gordon, Tessa; Borschel, Gregory H

    2015-11-01

    Chronic denervation resulting from long nerve regeneration times and distances contributes greatly to suboptimal outcomes following nerve injuries. Recent studies showed that multiple nerve grafts inserted between an intact donor nerve and a denervated distal recipient nerve stump (termed "side-to-side nerve bridges") enhanced regeneration after delayed nerve repair. To examine the cellular aspects of axon growth across these bridges to explore the "protective" mechanism of donor axons on chronically denervated Schwann cells. In Sprague Dawley rats, 3 side-to-side nerve bridges were placed over a 10-mm distance between an intact donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) distal nerve stump. Green fluorescent protein-expressing TIB axons grew across the bridges and were counted in cross section after 4 weeks. Immunofluorescent axons and Schwann cells were imaged over a 4-month period. Denervated Schwann cells dedifferentiated to a proliferative, nonmyelinating phenotype within the bridges and the recipient denervated CP nerve stump. As donor TIB axons grew across the 3 side-to-side nerve bridges and into the denervated CP nerve, the Schwann cells redifferentiated to the myelinating phenotype. Bridge placement led to an increased mass of hind limb anterior compartment muscles after 4 months of denervation compared with muscles whose CP nerve was not "protected" by bridges. This study describes patterns of donor axon regeneration and myelination in the denervated recipient nerve stump and supports a mechanism where these donor axons sustain a proregenerative state to prevent deterioration in the face of chronic denervation.

  16. End-to-side and end-to-end anastomoses give similar results in cervical oesophagogastrostomy.

    Pierie, J P; De Graaf, P W; Poen, H; Van Der Tweel, I; Obertop, H

    1995-12-01

    To find out if there were any differences in healing between end-to-end and end-to-side anastomoses for oesophagogastrostomy. Open study with historical controls. University hospital, The Netherlands. 28 patients with end-to-end and 90 patients with end-to-side anastomoses after transhiatal oesophagectomy and partial gastrectomy for cancer of the oesophagus or oesophagogastric junction, with gastric tube reconstruction and cervical anastomosis. Leak and stricture rates, and the number of dilatations needed to relieve dysphagia. There were no significant differences in leak rates (end-to-end 4/28, 14%, and end-to-side 13/90, 14%) or anastomotic strictures (end-to-end 9/28, 32%, and end-to-side 26/90, 29%). The median number of dilatations needed to relieve dysphagia was 7 (1-33) after end-to-end and 9 (1-113) after end-to-side oesophagogastrostomy. There were no differences between the two methods of suture of cervical oesophagogastrostomy when leakage, stricture, and number of dilatations were used as criteria of good healing.

  17. Neuroma prevention by end-to-side neurorraphy: an experimental study in rats.

    Aszmann, Oskar C; Korak, Klaus J; Rab, Matthias; Grünbeck, Matthias; Lassmann, Hans; Frey, Manfred

    2003-11-01

    The successful treatment of painful neuromas remains a difficult goal to attain. In this report we explore the feasibility of neuroma prevention by insertion of the proximal end of a nerve through an end-to-side neurorraphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. Experiments were performed on a total of twenty 250-g Sprague-Dawley rats. Two groups of 10 animals were prepared. Group A served as an anatomic control. In group B the right saphenous nerve was transected and implanted end-to-side through an epineurial window into the tibial nerve distal to the trifurcation of the sciatic nerve. After 12 weeks the corresponding sensory neurons were identified by retrograde labeling techniques and histomorphometric analysis of the proximal and distal tibial nerve segments, and regular histology of the end-to-side site were performed. The results of the retrograde labeling of the corresponding sensory neuron pool of the saphenus nerve showed extensive labelling of the L1 to L3 spinal ganglions after intracutaneous tracer application of the planta pedis. The morphology of the end-to-side coaptation site and histomorphologic analysis prove that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwann cell tubes toward their targets. Axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented. Whether these axons will lead to disturbing sensations such as paresthesia or dysesthesia in the newly found environment or remain silent codwellers, this experiment cannot answer. Long-term results of future clinical work will have to decide whether the prevention of the neuroma through end-to-side coaptation will be an appropriate therapy for this difficult problem.

  18. Wrist and Hand Ultrasound: Reliability of Side-to-Side Comparisons of Very Small (Structures.

    Rossi, Federica; Romano, Nicola; Muda, Alessandro; Martinoli, Carlo; Tagliafico, Alberto

    2018-04-24

    In ultrasound (US) examinations of clinically relevant very small structures of the wrist and hand, the healthy contralateral side can be used as a reference to identify subtle abnormalities. Intraindividual side-to-side variability must be minimal. The aim of this study was to assess the reliability of side-to-side US evaluations of very small structures of the wrist and hand. Forty-one healthy volunteers were prospectively studied. Small structures of the wrist and hand were evaluated bilaterally by 2 musculoskeletal radiologists in separate sessions. The first annular pulleys of the second finger and the thumb, sagittal band of the third finger, extensor and flexor retinacula, ulnar collateral ligament of the thumb, radial collateral ligament of the second finger, and palmar cutaneous branches of the median and ulnar nerves were considered. To assess intra- and inter-reader agreement, 10 of 41 (24%) examinations were repeated. Nonparametric statistics were used. Data were not normally distributed (P > .001). Intra-reader agreement was κ = 0.674 (95% confidence interval [CI], 0.57-0.78), and inter-reader agreement was κ = 0.935 (95% CI, 0.92-0.95). The mean value ± SD for all of the structures was 0.78 ± 0.44 mm. The overall coefficient of variation was 9.8% ± 0.07%. The intraclass correlation coefficient was 0.97 (95% CI, 0.96-0.98). In clinical practice, the healthy contralateral side can be used as a reference during a real-time musculoskeletal US evaluation of small (structures. © 2018 by the American Institute of Ultrasound in Medicine.

  19. A gastrocnemius heterotopical transplant model with end-to-side neurorraphy.

    Jaeger, Marcos Ricardo de Oliveira; Silva, Jefferson Luis Braga; Bain, James; Ely, Pedro Bins; Pires, Jefferson André; Ferreira, Lydia Masako

    2014-01-01

    To present an animal model to assess the effects of end-to-side innervation in the heterotopically transplanted model with reduced chances of neural contamination. The medial portion of the gastrocnemius muscle in wistar male rats was isolated and its pedicle dissected and performed a flap in the abdominal portion. To prevent neural contamination in the abdominal region, the muscle was wrapped with a Goretex(r) sheet. The specimens were divided into 2 groups (G). In G1 was performed an end-to-end suture between tibial nerve of the gastrocnemius and femoral motor nerve and between the saphenous sensory nerve and the motor nerve. In G2 was performed a end-to-side suture between the tibial nerve and the motor femoral and between the tibial nerve and saphenous motor nerve. The specimens were evaluated 60 days later to check the structure of the neurorraphy. Sections were obtained proximal and distal to the coaptation site. The medial gastrocnemius muscle had the advantage of maintaining visible mass after 60 days. No disruption of the coaptation site was found. No major injury to the donor nerve was seen in group 2. The proposed model is simple, reproduciple and prevent the neural contamination in the flap in end-to-side suture.

  20. The study of CD side to side error in line/space pattern caused by post-exposure bake effect

    Huang, Jin; Guo, Eric; Ge, Haiming; Lu, Max; Wu, Yijun; Tian, Mingjing; Yan, Shichuan; Wang, Ran

    2016-10-01

    In semiconductor manufacturing, as the design rule has decreased, the ITRS roadmap requires crucial tighter critical dimension (CD) control. CD uniformity is one of the necessary parameters to assure good performance and reliable functionality of any integrated circuit (IC) [1] [2], and towards the advanced technology nodes, it is a challenge to control CD uniformity well. The study of corresponding CD Uniformity by tuning Post-Exposure bake (PEB) and develop process has some significant progress[3], but CD side to side error happening to some line/space pattern are still found in practical application, and the error has approached to over the uniformity tolerance. After details analysis, even though use several developer types, the CD side to side error has not been found significant relationship to the developing. In addition, it is impossible to correct the CD side to side error by electron beam correction as such error does not appear in all Line/Space pattern masks. In this paper the root cause of CD side to side error is analyzed and the PEB module process are optimized as a main factor for improvement of CD side to side error.

  1. Double muscle innervation using end-to-side neurorrhaphy in rats

    Elisangela Jeronymo Stipp-Brambilla

    Full Text Available CONTEXT AND OBJECTIVE: One of the techniques used for treating facial paralysis is double muscle innervation using end-to-end neurorrhaphy with sectioning of healthy nerves. The aim of this study was to evaluate whether double muscle innervation by means of end-to-side neurorrhaphy could occur, with maintenance of muscle innervation. DESIGN AND SETTING: Experimental study developed at the Experimental Research Center, Faculdade de Medicina de Botucatu, Unesp. METHODS: One hundred rats were allocated to five groups as follows: G1, control group; G2, the peroneal nerve was sectioned; G3, the tibial nerve was transected and the proximal stump was end-to-side sutured to the intact peroneal nerve; G4, 120 days after the G3 surgery, the peroneal nerve was sectioned proximally to the neurorrhaphy; G5, 120 days after the G3 surgery, the peroneal and tibial nerves were sectioned proximally to the neurorrhaphy. RESULTS: One hundred and fifty days after the surgery, G3 did not show any change in tibial muscle weight or muscle fiber diameter, but the axonal fiber diameter in the peroneal nerve distal to the neurorrhaphy had decreased. Although G4 showed atrophy of the cranial tibial muscle 30 days after sectioning the peroneal nerve, the electrophysiological test results and axonal diameter measurement confirmed that muscle reinnervation had occurred. CONCLUSION: These findings suggest that double muscle innervation did not occur through end-to-side neurorrhaphy; the tibial nerve was not able to maintain muscle innervation after the peroneal nerve had been sectioned, although muscle reinnervation was found to have occurred, 30 days after the peroneal nerve had been sectioned.

  2. A gastrocnemius heterotopical transplant model with end-to-side neurorraphy

    Jaeger, Marcos Ricardo de Oliveira; Braga Silva, Jefferson [UNIFESP; Bain, James; Ely, Pedro Bins; Pires, Jefferson André; Ferreira, Lydia Masako [UNIFESP

    2014-01-01

    PURPOSE:To present an animal model to assess the effects of end-to-side innervation in the heterotopically transplanted model with reduced chances of neural contamination.METHODS: The medial portion of the gastrocnemius muscle in wistar male rats was isolated and its pedicle dissected and performed a flap in the abdominal portion. To prevent neural contamination in the abdominal region, the muscle was wrapped with a Goretex(r) sheet. The specimens were divided into 2 groups (G). In G1 was per...

  3. [Preliminary investigation of treatment of ulnar nerve defect by end-to-side neurorrhaphy].

    Luo, Y; Wang, T; Fang, H

    1997-11-01

    In the repair of the defect of peripheral nerve, it was necessary to find an operative method with excellent therapeutic effect but simple technique. Based on the experimental study, one case of old injury of the ulnar nerve was treated by end-to-side neurorraphy with the intact median nerve. In this case the nerve defect was over 3 cm and unable to be sutured directly. The patient was followed up for fourteen months after the operation. The recovery of the sensation and the myodynamia was evaluated. The results showed that: the sensation and the motor function innervated by ulnar nerve were recovered. The function of the hand was almost recovered to be normal. It was proved that the end-to-side neurorraphy between the distal stump with the intact median nerve to repair the defect of the ulnar nerve was a new operative procedure for nerve repair. Clinically it had good effect with little operative difficulty. This would give a bright prospect to repair of peripheral nerve defect in the future.

  4. End-to-side nerve neurorrhaphy: critical appraisal of experimental and clinical data.

    Fernandez, E; Lauretti, L; Tufo, T; D'Ercole, M; Ciampini, A; Doglietto, F

    2007-01-01

    End-to-side neurorrhaphy (ESN) or terminolateral neurorraphy consists of connecting the distal stump of a transected nerve, named the recipient nerve, to the side of an intact adjacent nerve, named the donor nerve, "in which only an epineurial window is performed". This procedure was reintroduced in 1994 by Viterbo, who presented a report on an experimental study in rats. Several experimental and clinical studies followed this report with various and sometimes conflicting results. In this paper we present a review of the pertinent literature. Our personal experience using a sort of end-to-side nerve anastomosis, in which the donor nerve is partially transected, is also presented and compared with ESN as defined above. When the proximal nerve stump of a transected nerve is not available, ESN, which is claimed to permit anatomic and functional preservation of the donor nerve, seems an attractive technique, though yet not proven to be effective. Deliberate axotomy of the donor nerve yields results that are proportional to the entity of axotomy, but such technique, though resembling ESN, is an end-to-end neurorrhaphy. Neither experimental or clinical evidence support liberalizing the clinical use of ESN, a procedure with only an epineurial window in the donor nerve and without deliberate axotomy. Much more experimental investigation needs to be done to explain the ability of normal, intact nerves to sprout laterally. Such procedure appears justified only in an investigational setting.

  5. Testing the effectiveness and the contribution of experimental supercharge (reversed) end-to-side nerve transfer.

    Nadi, Mustafa; Ramachandran, Sudheesh; Islam, Abir; Forden, Joanne; Guo, Gui Fang; Midha, Rajiv

    2018-05-18

    OBJECTIVE Supercharge end-to-side (SETS) transfer, also referred to as reverse end-to-side transfer, distal to severe nerve compression neuropathy or in-continuity nerve injury is gaining clinical popularity despite questions about its effectiveness. Here, the authors examined SETS distal to experimental neuroma in-continuity (NIC) injuries for efficacy in enhancing neuronal regeneration and functional outcome, and, for the first time, they definitively evaluated the degree of contribution of the native and donor motor neuron pools. METHODS This study was conducted in 2 phases. In phase I, rats (n = 35) were assigned to one of 5 groups for unilateral sciatic nerve surgeries: group 1, tibial NIC with distal peroneal-tibial SETS; group 2, tibial NIC without SETS; group 3, intact tibial and severed peroneal nerves; group 4, tibial transection with SETS; and group 5, severed tibial and peroneal nerves. Recovery was evaluated biweekly using electrophysiology and locomotion tasks. At the phase I end point, after retrograde labeling, the spinal cords were analyzed to assess the degree of neuronal regeneration. In phase II, 20 new animals underwent primary retrograde labeling of the tibial nerve, following which they were assigned to one of the following 3 groups: group 1, group 2, and group 4. Then, secondary retrograde labeling from the tibial nerve was performed at the study end point to quantify the native versus donor regenerated neuronal pool. RESULTS In phase I studies, a significantly increased neuronal regeneration in group 1 (SETS) compared with all other groups was observed, but with modest (nonsignificant) improvement in electrophysiological and behavioral outcomes. In phase II experiments, the authors discovered that secondary labeling in group 1 was predominantly contributed from the donor (peroneal) pool. Double-labeling counts were dramatically higher in group 2 than in group 1, suggestive of hampered regeneration from the native tibial motor neuron pool

  6. Influence of suture technique and suture material selection on the mechanics of end-to-end and end-to-side anastomoses.

    Baumgartner, N; Dobrin, P B; Morasch, M; Dong, Q S; Mrkvicka, R

    1996-05-01

    Experiments were performed in dogs to evaluate the mechanics of 26 end-to-end and 42 end-to-side artery-vein graft anastomoses constructed with continuous polypropylene sutures (Surgilene; Davis & Geck, Division of American Cyanamid Co., Danbury, Conn.), continuous polybutester sutures (Novafil; Davis & Geck), and interrupted stitches with either suture material. After construction, the grafts and adjoining arteries were excised, mounted in vitro at in situ length, filled with a dilute barium sulfate suspension, and pressurized in 25 mm Hg steps up to 200 mm Hg. Radiographs were obtained at each pressure. The computed cross-sectional areas of the anastomoses were compared with those of the native arteries at corresponding pressures. Results showed that for the end-to-end anastomoses at 100 mm Hg the cross-sectional areas of the continuous Surgilene anastomoses were 70% of the native artery cross-sectional areas, the cross-sectional areas of the continuous Novafil anastomoses were 90% of the native artery cross-sectional areas, and the cross-sectional areas of the interrupted anastomoses were 107% of the native artery cross-sectional areas (p anastomoses demonstrated no differences in cross-sectional areas or compliance for the three suture techniques. This suggests that, unlike with end-to-end anastomoses, when constructing an end-to-side anastomosis in patients any of the three suture techniques may be acceptable.

  7. Geometric Three-Dimensional End-to-Side Microvascular Anastomosis: A Simple and Reproducible Technique.

    Ooi, Adrian S H; Butz, Daniel R; Fisher, Sean M; Collier, Zachary J; Gottlieb, Lawrence J

    2018-05-01

    End-to-side (ETS) anastomoses are useful when preservation of distal vascularity is critical. The ideal ETS microanastomosis should maintain a wide aperture and have a smooth take-off point to minimize turbulence, vessel spasm, and thrombogenicity of the suture line. We have developed a unique, dependable, and reproducible geometric technique for ETS anastomoses, and analyze its efficacy in our series of patients.  The geometric ETS technique involves creating a three-dimensional (3D) diamond-shaped defect on the recipient vessel wall, followed by a slit incision of the donor vessel to create a "spatula" fitting this defect. This technique removes sutures from the point of most turbulent blood flow while holding the recipient vessel open with a patch vesselplasty effect. We perform a retrospective review of a single surgeon's experience using this technique.  The geometric 3D ETS technique was used in 87 free flaps with a total of 102 ETS anastomoses in a wide range of cases including head and neck, trunk and genitourinary, and extremity reconstruction. Overall, free flap success rates were 98%.  The geometric 3D ETS technique creates a wide anastomosis, minimizes turbulence-inducing thrombogenicity, and mechanically holds the recipient vessel open. It is reliable and reproducible, and when performed properly has been shown to have high rates of success in a large group of free tissue transfer patients. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  8. Modified temporary end-to-side portocaval shunt in liver and small bowel transplantation.

    Molmenti, E P; Marsh, J W; Molmenti, H; Reyes, J; Fung, J J

    2001-10-01

    Piggyback orthotopic liver transplantation (LTx) has permitted the elimination of extra-corporeal venovenous bypass. In some instances, an internal temporary portocaval shunt has to be constructed in order to prevent hemodynamic instability. We describe a technique in which a donor iliac vein graft is used to bridge the distance between the portal vein and vena cava in cases where a direct shunt cannot be constructed. This technique can be applied to liver Tx as well as to liver and small bowel Tx.

  9. PIV-validated numerical modeling of pulsatile flows in distal coronary end-to-side anastomoses.

    Xiong, F L; Chong, C K

    2007-01-01

    This study employed particle image velocimetry (PIV) to validate a numerical model in a complementary approach to quantify hemodynamic factors in distal coronary anastomoses and to gain more insights on their relationship with anastomotic geometry. Instantaneous flow fields and wall shear stresses (WSS) were obtained from PIV measurement in a modified life-size silastic anastomosis model adapted from a conventional geometry by incorporating a smooth graft-artery transition. The results were compared with those predicted by a concurrent numerical model. The numerical method was then used to calculate cycle-averaged WSS (WSS(cyc)) and spatial wall shear stress gradient (SWSSG), two critical hemodynamic factors in the pathogenesis of intimal thickening (IT), to compare the conventional and modified geometries. Excellent qualitative agreement and satisfactory quantitative agreement with averaged normalized error in WSS between 0.8% and 8.9% were achieved between the PIV experiment and numerical model. Compared to the conventional geometry, the modified geometry produces a more uniform WSS(cyc) distribution eliminating both high and low WSS(cyc) around the toe, critical in avoiding IT. Peak SWSSG on the artery floor of the modified model is less than one-half that in the conventional case, and high SWSSG at the toe is eliminated. The validated numerical model is useful for modeling unsteady coronary anastomotic flows and elucidating the significance of geometry regulated hemodynamics. The results suggest the clinical relevance of constructing smooth graft-artery transition in distal coronary anastomoses to improve their hemodynamic performance.

  10. End-to-side neurorraphy: a long-term study of neural regeneration in a rat model.

    Tarasidis, G; Watanabe, O; Mackinnon, S E; Strasberg, S R; Haughey, B H; Hunter, D A

    1998-10-01

    This study evaluated long-term reinnervation of an end-to-side neurorraphy and the resultant functional recovery in a rat model. The divided distal posterior tibial nerve was repaired to the side of an intact peroneal nerve. Control groups included a cut-and-repair of the posterior tibial nerve and an end-to-end repair of the peroneal nerve to the posterior tibial nerve. Evaluations included walking-track analysis, nerve conduction studies, muscle mass measurements, retrograde nerve tracing, and histologic evaluation. Walking tracks indicated poor recovery of posterior tibial nerve function in the experimental group. No significant difference in nerve conduction velocities was seen between the experimental and control groups. Gastrocnemius muscle mass measurements revealed no functional recovery in the experimental group. Similarly, retrograde nerve tracing revealed minimal motor neuron staining in the experimental group. However, some sensory staining was seen within the dorsal root ganglia of the end-to-side group. Histologic study revealed minimal myelinated axonal regeneration in the experimental group as compared with findings in the other groups. These results suggest that predominantly sensory regeneration occurs in an end-to-side neurorraphy at an end point of 6 months.

  11. Comparing outcomes between side-to-side anastomosis and other anastomotic configurations after intestinal resection for patients with Crohn's disease: a meta-analysis.

    Guo, Zhen; Li, Yi; Zhu, Weiming; Gong, Jianfeng; Li, Ning; Li, Jieshou

    2013-04-01

    Anastomotic configurations may be a predictor of postoperative recurrence for Crohn's disease. One previous meta-analysis showed side-to-side anastomosis was associated with fewer anastomotic leaks but did not reduce postoperative recurrence rates. After 2007, more articles that found distinct results were published. We aimed to update the meta-analysis comparing outcomes between side-to-side anastomosis and other anastomotic configurations after intestinal resection for patients with Crohn's disease. A literature search that included PubMed, EMBASE, the Science Citation Index, and the Cochrane Library was conducted to identify studies up to May 2012. Trials comparing side-to-side anastomosis with other anastomotic configurations for Crohn's disease were analyzed. Sensitivity analysis and heterogeneity assessment were also performed. Eleven trials compared side-to-side with other anastomotic configurations were included. Overall, results showed a significant reduction in the overall postoperative complications [n = 777; odds ratio (OR) = 0.60; P = 0.01], but side-to-side anastomosis did not reduce the anastomotic leak rate (n = 879; OR = 0.48; P = 0.07), complications other than anastomotic leak (n = 777; OR = 0.72; P = 0.13), endoscopic recurrence rates [hazard ratio (HR) = 0.73; P = 0.07], symptomatic recurrence rates (HR = 0.74; P = 0.20), and reoperation rates for recurrence (HR = 0.37; P = 0.06). Sensitivity analysis including two randomized controlled trials found no significant differences in short-term complications between the two groups. Sensitivity analysis including nine trials comparing only stapled side-to-side anastomosis with other anastomotic configurations showed stapled side-to-side anastomosis could reduce reoperation rates (HR = 0.38; P = 0.01). Side-to-side anastomosis did not reduce short-term complications and postoperative recurrence for Crohn's disease. Stapled side-to-side anastomosis may lead to fewer reoperations needed for recurrence

  12. Side-to-side differences in lower extremity biomechanics during multi-directional jump landing in volleyball athletes.

    Sinsurin, Komsak; Srisangboriboon, Sarun; Vachalathiti, Roongtiwa

    2017-07-01

    Side-to-side differences of lower extremities may influence the likelihood of injury. Moreover, adding the complexity of jump-landing direction would help to explain lower extremity control during sport activities. The aim was to determine the effects of limb dominance and jump-landing direction on lower extremity biomechanics. Nineteen female volleyball athletes participated. Both dominant limbs (DLs) and non-dominant limbs (NLs) were examined in single-leg jump-landing tests in four directions, including forward (0°), diagonal (30° and 60°), and lateral (90°) directions. Kinematic marker trajectories and ground reaction forces were collected using a 10 camera Vicon system and an AMTI force plate. Repeated measures ANOVA (2 × 4, limb × direction) was used to analyse. The finding showed that, at peak vertical GRF, a significant interaction of limb dominance and direction effects was found in the hip flexion angle and lower extremity joint kinetics (p < .05). NLs and DLs exhibited significantly different strategies while landing in various directions. Significantly higher increase of ankle dorsiflexion angle was observed in lateral direction compared to other directions for both DLs and NLs (p < .05). Increasingly using ankle dorsiflexion was observed from the forward to the lateral direction for both DLs and NLs. However, NLs and DLs preferentially used different strategies of joint moment organization to respond to similar VGRFs in various directions. The response pattern of DLs might not be effective and may expose DLs to a higher injury risk, especially with regard to landing with awkward posture compared with NLs.

  13. Use of end-to-side arterial and venous anastomosis techniques for renal transplantation in two dogs.

    Phillips, Heidi; Aronson, Lillian R

    2012-02-01

    A sexually intact male Old English Sheepdog and a sexually intact female Bull Terrier were evaluated for renal dysplasia and chronic renal failure, respectively. Both dogs were anemic and had high serum concentrations of urea nitrogen and creatinine. Electrolyte abnormalities (calcium and phosphorus) were also evident. The decision was made to pursue renal transplantation, and donor dogs were identified. End-to-side anastomosis of the renal artery and vein of each donor's left kidney to the recipient's ipsilateral external iliac artery and vein, respectively, was performed. The left caudal abdominal musculature was scarified by making an incision, and nephropexy to that musculature was performed with a simple interrupted pattern of polypropylene sutures. No intraoperative or postoperative complications associated with the vascular anastomoses were encountered. Azotemia, anemia, and electrolyte imbalances resolved after transplantation. The end-to-side anastomosis technique described here, which is a preferred method in human medicine, was successful, providing an alternative to other renal transplantation techniques in dogs. Additional studies are needed to determine whether any vascular anastomosis technique is preferable for use in dogs requiring renal transplantation.

  14. Longitudinal forces acting at side-to-end and end-to-side anastomoses when a knitted polyester arterial prosthesis is implanted in the dog.

    Dadgar, L; Downs, A R; Deng, X; Marois, Y; King, M W; Martin, L; Guidoin, R

    1995-01-01

    In a previous study, which investigated the tensions at the proximal and distal end-to-end anastomoses of a vascular prosthesis, no significant differences were found in the longitudinal forces between the two anastomotic sites after different periods of implantation. The present follow-up study was devised to study the longitudinal forces at a proximal side-to-end and a distal end-to-side anastomosis using a warp knitted polyester prosthesis implanted as a canine thorocoabdominal bypass. The external surface of the prosthesis contained a specially printed "tension indicator" design, which enabled changes in length to be assessed photographically at the two anastomoses at the time of implantation and at sacrifice. The longitudinal force at each site was then calculated using a relationship obtained experimentally between the total longitudinal force and the changes in length of the virgin graft in vitro. The in vitro measurements on the prosthesis were performed using a computer-controlled laser calibration system. Although the results showed a tendency toward a gradual loss in longitudinal force at both anastomoses over 7 months in situ, statistical analysis showed no significant difference in the longitudinal force at the two anastomotic sites after any period of implantation. Histopathological and textile analysis also showed that the characteristics of the prostheses were similar at both anastomotic sites. This does not mean, however, that the intramural stress concentrations experienced by the two sites were the same. While comparing the level of the longitudinal forces measured in this study with those observed in the previous thoracic aorta study using end-to-end anastomoses, no significant differences were observed due to the different types of anastomoses. It would appear that the longitudinal force is not one of the main etiological factors that cause the formation and localization of anastomotic failure.

  15. Numerical investigations of the unsteady blood flow in the end-to-side arteriovenous fistula for hemodialysis.

    Jodko, Daniel; Obidowski, Damian; Reorowicz, Piotr; Jóźwik, Krzysztof

    2016-01-01

    The aim of this study was to investigate the blood flow in the end-to-side arteriovenous (a-v) fistula, taking into account its pulsating nature and the patient-specific geometry of blood vessels. Computational Fluid Dynamics (CFD) methods were used for this analysis. DICOM images of the fistula, obtained from the angio-computed tomography, were a source of the data applied to develop a 3D geometrical model of the fistula. The model was meshed, then the ANSYS CFX v. 15.0 code was used to perform simulations of the flow in the vessels under analysis. Mesh independence tests were conducted. The non-Newtonian rheological model of blood and the Shear Stress Transport model of turbulence were employed. Blood vessel walls were assumed to be rigid. Flow patterns, velocity fields, the volume flow rate, the wall shear stress (WSS) propagation on particular blood vessel walls were shown versus time. The maximal value of the blood velocity was identified in the anastomosis - the place where the artery is connected to the vein. The flow rate was calculated for all veins receiving blood. The blood flow in the geometrically complicated a-v fistula was simulated. The values and oscillations of the WSS are the largest in the anastomosis, much lower in the artery and the lowest in the cephalic vein. A strong influence of the mesh on the results concerning the maximal and area-averaged WSS was shown. The relation between simulations of the pulsating and stationary flow under time-averaged flow conditions was presented.

  16. End-to-side neurotization with the phrenic nerve in restoring the function of toe extension: an experimental study in a rat model.

    Jia, Xiaotian; Chen, Chao; Yang, Jianyun; Yu, Cong

    2018-06-01

    The phrenic nerve being transferred to the posterior division of the lower trunk with end-to-end neurorrhaphy is reported to be effective in restoring the function of digit extension in literature. However, the phrenic nerve is extremely important in respiration. We designed an animal experiment to discover whether the phrenic nerve being transferred to the posterior division of the lower trunk with end-to-side neurotization was feasible and provided the theoretical basis. A sum of 36 Sprague-Dawley rats was randomly assigned to one of two groups. In Group A, the phrenic nerve was transferred to the posterior division of the lower trunk with end-to-side neurotization. In Group B, the posterior division of the lower trunk was directly sutured. The results of behavioral assessment, electrophysiology, histology and nerve fiber count and muscle weight at 12 weeks postoperatively were recorded. In Group A, none of the rats experienced tachypnea. The motion of slight toe extension was observed. The results of electrophysiology, histology and nerve fiber count and muscle weight in Group A were not as well as those of Group B, but gradually improved with time. The phrenic nerve being transferred to the posterior division of lower trunk with end-to-side neurotization can partially restore the function of toe extension in a rat model. Whether the function of digit extension can be restored by the phrenic nerve with end-to-side neurotization in humans still needs more practice in clinic.

  17. SIDE TO SIDE DIFFERENCES BETWEEN DOMINANT AND NON-DOMINANT ARM'S BONE DENSITY AND ISOMETRIC HANDGRIP STRENGTH IN MALES AND FEMALES AGED 40-65 YEARS OLD.

    Krasniqi, Ermira; Koni, Mynyr; Kabashi, Antigona; Bahtiri, Abedin; Gjeli, Selda; Boshnjaku, Arben

    2016-10-01

    This observational, cross-sectional study, investigates and compares the differences of BMD, T-score, Z-score and isometric strength between dominant (D) versus non-dominant (ND) arms of 162 subjects aged 40-65 in a developing, low income country (Kosova). Bone Mineral Density (BMD), T-score and Z-score at distal forearm regions of both arms (measured by DXA scan), together with the Handgrip Isometric Strength (HIS) (by handgrip) were evaluated in a total subjects (53 Males and 109 Females). Additionally, General Healthcare Status Questionnaire together with self-administrated International Physical Activity Questionnaire (IPAQ) were filled. Significant differences (p0.05) were observed in Males BMD comparing to significantly higher results (p0.05) in males. When comparing the total subject's BMD, T-score, Z-score and Handgrip based on the PA levels (1 to 3 according to IPAQ scoring) no significant differences (p>0.05) were found between PA1, as well as PA3 whereas significantly differences (p<0.05) were found in D arms of PA2 level. The study analyses side-to-side differences in bone density and muscular force between D and ND arms amongst a population which is frequently exposed to diagnostic screenings for age related osteomuscular conditions (aged 40-60), and demonstrates that these differences should be in consideration amongst clinicians, but not in the way it is done right now.

  18. Stapled side-to-side anastomosis might be better than handsewn end-to-end anastomosis in ileocolic resection for Crohn's disease: a meta-analysis.

    He, Xiaosheng; Chen, Zexian; Huang, Juanni; Lian, Lei; Rouniyar, Santosh; Wu, Xiaojian; Lan, Ping

    2014-07-01

    Ileocolic anastomosis is an essential step in the treatment to restore continuity of the gastrointestinal tract following ileocolic resection in patients with Crohn's disease (CD). However, the association between anastomotic type and surgical outcome is controversial. The aim of this meta-analysis is to compare surgical outcomes between stapled side-to-side anastomosis (SSSA) and handsewn end-to-end anastomosis (HEEA) after ileocolic resection in patients with CD. Studies comparing SSSA with HEEA after ileocolic resection in patients with CD were identified in PubMed and EMBASE. Outcomes such as complication, recurrence, and re-operation were evaluated. Eight studies (three randomized controlled trials, one prospective non-randomized trial, and four non-randomized retrospective trials) comparing SSSA (396 cases) and HEEA (425 cases) were included. As compared with HEEA, SSSA was superior in terms of overall postoperative complications [odds ratio (OR), 0.54; 95 % confidence interval (CI) 0.32-0.93], anastomotic leak (OR 0.45; 95 % CI 0.20-1.00), recurrence (OR 0.20; 95 % CI 0.07-0.55), and re-operation for recurrence (OR 0.18; 95 % CI 0.07-0.45). Postoperative hospital stay, mortality, and complications other than anastomotic leak were comparable. Based on the results of our meta-analysis, SSSA would appear to be the preferred procedure after ileocolic resection for CD, with reduced overall postoperative complications, especially anastomotic leak, and a decreased recurrence and re-operation rate.

  19. Neurotization of the biceps muscle by end-to-side neurorraphy between ulnar and musculocutaneous nerves. A series of five cases.

    Franciosi, L F; Modestti, C; Mueller, S F

    1998-01-01

    Three patients with avulsed C5, C6, and C7 roots and two patients with avulsed C5 and C6 roots after trauma of the brachial plexus, were treated by neurotization of the biceps using nerve fibers derived from the ulnar nerve and obtained by end-to-side neurorraphy between the ulnar and musculocutaneous nerves. The age of patients ranged from 19 to 45. The interval between the accident and surgery was 2 to 13 months. Return of biceps contraction was observed 4 to 6 months after surgery. Four patients recovered grade 4 elbow flexion. One 45-year-old patient did not obtain any biceps contraction after 9 months.

  20. Stapled side-to-side anastomosis might be benefit in intestinal resection for Crohn's disease: A systematic review and network meta-analysis.

    Feng, Jin-Shan; Li, Jin-Yu; Yang, Zheng; Chen, Xiu-Yan; Mo, Jia-Jie; Li, Shang-Hai

    2018-04-01

    Intestinal anastomosis is an essential step in the intestinal resection in patients with Crohn's disease (CD). Anastomotic configuration such as handsewn end-to-end anastomosis (HEEA), stapled side-to-side anastomosis (SSSA) and so on may be a predictor of prognosis for postoperative CD patients. However, the association between anastomotic types and surgical outcomes are controversial. The aim of this review is to identify the optimal anastomosis for intestinal resection in patients with CD. Clinical trials comparing anastomosis after intestinal resection in patients with CD were searched in the database of MEDLINE, EMBASE, and the Cochrane Library. Outcomes such as postoperative hospital stay, complications, mortality, recurrence, and reoperation were evaluated. Pairwise treatment effects were estimated through a random-effects network meta-analysis based on the frequency framework by using the STATA software and reported as the estimated summary effect for each comparison between the 2 treatments in the network with a 95% credible interval. A total of 1113 patients in 11 trials were included. In pair-wise comparisons between groups, for overall postoperative complications, SSSA showed a more probability of superiority to HEEA; for complications other than anastomotic leak, anastomotic leak, wound infection, postoperative hospital stay and mortality, there were no significant difference between groups; for clinical recurrence, SSSA showed a more probability of superiority to HEEA; for reoperation, SSSA showed a more probability of superiority to HEEA. The number of eligible randomized controlled trails (RCTs) was small, and more than half of the included trials were retrospective studies; selection bias may lead to a less power in this assessment; follow-up time between different groups was different, which may possibly have affected the interpretation of the analysis of long-term outcome. By comprehensive analyzing all the postoperative outcomes, SSSA appeared

  1. The in situ side-to-side bypass technique: a comprehensive review of the technical characteristics, current anastomosis approaches and surgical experience.

    Wang, Long; Cai, Li; Qian, Hai; Lawton, Michael T; Shi, Xiang'en

    2018-05-02

    In situ side-to-side (STS) revascularization is an intracranial-intracranial (IC-IC) bypass technique that is increasingly used to treat complex aneurysms and cerebral ischemia. This sophisticated technique involves connecting two proximal parallel vessels to create an artificial conduit for blood flow. This study aims to provide a detailed description of the configuration of the STS bypass technique and extensive information regarding its technical characteristics, current anastomosis approaches and surgical significance. A literature search was performed using the PubMed, Medline, ScienceDirect, Embase, Wiley Online Library, Cambridge Journals, SAGE Journals, Oxford Journals, Research Gate, and Google Scholar databases. The terms "intracranial-intracranial bypass", "in situ bypass", "communicating bypass" and "STS anastomosis" were searched to identify pertinent articles. Articles involving in situ STS anastomosis combined with other bypass methods were excluded. Computer tablet-drawn illustrations of this technique are provided to enhance comprehension. In total, seventy articles that met our search and inclusion criteria were identified. Overall, the radiographical and clinical outcomes of one-hundred and thirty-two (125 aneurysm and 7 cerebral ischemia) patients who underwent in situ STS revascularization were analyzed. IC-IC bypass in the STS fashion can be a safe and effective strategy for the management of complex intracranial aneurysms and cerebral ischemia and is particularly attractive in rescue, anticipated and troubleshooting cases. Despite its extreme rarity, a de novo aneurysm may be observed following STS anastomosis; thus, long-term follow-up is mandatory. Vascular neurosurgeons should consider including this procedure in their treatment armamentarium. Copyright © 2018. Published by Elsevier Inc.

  2. Grafting

    Garnett, J L [New South Wales Univ., Kensington (Australia). School of Chemistry

    1979-01-01

    The unique value of ionizing radiation for the initiation of grafting to backbone polymers is discussed. The principles of the technique are briefly reviewed. The conditions under which free radicals and ions participate in these reactions are examined. Examples of representative grafting processes are considered to illustrate where the technique can be of potential commercial value to a wide range of industries. The general principles of these grafting reactions are shown to be applicable to radiation induced rapid cure technology such as is provided by electron beam processing facilities. Grafting reactions initiated by UV are also treated and shown to be of importance because of the many similarities in properties of the ionizing radiation and UV systems, also the rapid industrial exploitation of EB and sensitized UV processing technology. Possible future trends in radiation grafting are outlined.

  3. The effects of FK1706 on nerve regeneration and bladder function recovery following an end-to-side neurorrhaphy in rats.

    Gao, Wansheng; He, Xiangfei; Li, Yunlong; Wen, Jianguo

    2017-11-07

    Immunophilin ligands are neuroregenerative agents binding to FK506 binding proteins, by which stimulate recovery of neurons in a variety of injury nerves. FK1706 is a novel immunophilin ligand which has neuroprotective and neuroregenerative effects but without immunosuppressive activity. At present, most reports about FK1706 in ameliorating nerve injury and functional recovery are limited to cavernous nerve injury and erectile function recovery. This study aimed to demonstrate the effects of FK1706 on nerve regeneration and bladder function recovery following an end-to-side neurorrhaphy in rat models. The numbers of regenerated myelinated axons of the pelvic parasympathetic nerve (PPN) in the three groups' rats (FK1706 + ETS, ETS and control groups) were evaluated. Their intravesical pressure (IVP), S100β and growth associated protein 43 (GAP43) expressions were also compared. In FK1706 + ETS group, 90% the rats showed that the frequency of FG labeled neurons was larger than the 3.5 cutoff value, 100% the rats showed that the frequency of FG-FB double-labeled neurons was larger than the 5.5 cutoff value. The average maximum of IVP in FK1706 + ETS group reached 76.3% of the value in control group. Their average number of myelinated axons of regenerated PPN reached 80% of the amount in control group. The nerve regeneration-associated markers data indicated that the expression level of S100β and GAP43 in FK1706 + ETS group was approximately 2-fold higher than that of ETS group (P side neurorrhaphy, FK1706 effectively enhanced the nerve regeneration and bladder function recovery.

  4. Double muscle innervation using end-to-side neurorrhaphy in rats Dupla inervação muscular com neurorrafia término-lateral em ratos

    Elisangela Jeronymo Stipp-Brambilla

    2012-01-01

    Full Text Available CONTEXT AND OBJECTIVE: One of the techniques used for treating facial paralysis is double muscle innervation using end-to-end neurorrhaphy with sectioning of healthy nerves. The aim of this study was to evaluate whether double muscle innervation by means of end-to-side neurorrhaphy could occur, with maintenance of muscle innervation. DESIGN AND SETTING: Experimental study developed at the Experimental Research Center, Faculdade de Medicina de Botucatu, Unesp. METHODS: One hundred rats were allocated to five groups as follows: G1, control group; G2, the peroneal nerve was sectioned; G3, the tibial nerve was transected and the proximal stump was end-to-side sutured to the intact peroneal nerve; G4, 120 days after the G3 surgery, the peroneal nerve was sectioned proximally to the neurorrhaphy; G5, 120 days after the G3 surgery, the peroneal and tibial nerves were sectioned proximally to the neurorrhaphy. RESULTS: One hundred and fifty days after the surgery, G3 did not show any change in tibial muscle weight or muscle fiber diameter, but the axonal fiber diameter in the peroneal nerve distal to the neurorrhaphy had decreased. Although G4 showed atrophy of the cranial tibial muscle 30 days after sectioning the peroneal nerve, the electrophysiological test results and axonal diameter measurement confirmed that muscle reinnervation had occurred. CONCLUSION: These findings suggest that double muscle innervation did not occur through end-to-side neurorrhaphy; the tibial nerve was not able to maintain muscle innervation after the peroneal nerve had been sectioned, although muscle reinnervation was found to have occurred, 30 days after the peroneal nerve had been sectioned.CONTEXTO E OBJETIVO: Uma das técnicas utilizadas para tratamento da paralisia facial é a dupla inervação muscular com neurorrafia término-terminal, seccionando-se nervos sadios. O objetivo deste trabalho foi avaliar a ocorrência de dupla inervação muscular através de

  5. SIDE TO SIDE DIFFERENCES BETWEEN DOMINANT AND NON-DOMINANT ARM’S BONE DENSITY AND ISOMETRIC HANDGRIP STRENGTH IN MALES AND FEMALES AGED 40-65 YEARS OLD

    Krasniqi, Ermira; Koni, Mynyr; Kabashi, Antigona; Bahtiri, Abedin; Gjeli, Selda; Boshnjaku, Arben

    2016-01-01

    Objective: This observational, cross-sectional study, investigates and compares the differences of BMD, T-score, Z-score and isometric strength between dominant (D) versus non-dominant (ND) arms of 162 subjects aged 40-65 in a developing, low income country (Kosova). Material and Methods: Bone Mineral Density (BMD), T-score and Z-score at distal forearm regions of both arms (measured by DXA scan), together with the Handgrip Isometric Strength (HIS) (by handgrip) were evaluated in a total subjects (53 Males and 109 Females). Additionally, General Healthcare Status Questionnaire together with self-administrated International Physical Activity Questionnaire (IPAQ) were filled. Results: Significant differences (p0.05) were observed in Males BMD comparing to significantly higher results (p0.05) in males. When comparing the total subject’s BMD, T-score, Z-score and Handgrip based on the PA levels (1 to 3 according to IPAQ scoring) no significant differences (p>0.05) were found between PA1, as well as PA3 whereas significantly differences (p<0.05) were found in D arms of PA2 level. Conclusion: The study analyses side-to-side differences in bone density and muscular force between D and ND arms amongst a population which is frequently exposed to diagnostic screenings for age related osteomuscular conditions (aged 40-60), and demonstrates that these differences should be in consideration amongst clinicians, but not in the way it is done right now. PMID:27999479

  6. Skin graft

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

  7. Skin Graft

    Shimizu, Ruka; Kishi, Kazuo

    2012-01-01

    Skin graft is one of the most indispensable techniques in plastic surgery and dermatology. Skin grafts are used in a variety of clinical situations, such as traumatic wounds, defects after oncologic resection, burn reconstruction, scar contracture release, congenital skin deficiencies, hair restoration, vitiligo, and nipple-areola reconstruction. Skin grafts are generally avoided in the management of more complex wounds. Conditions with deep spaces and exposed bones normally require the use o...

  8. Pancreas grafts

    Hahn, D.; Buell, U.; Land, W.; Unertl, K.

    1981-01-01

    Perfusion studies with sup(99m)Tc-DTPA, which has hitherto been used routinely to investigate renal grafts, have also proved useful for monitoring the perfusion of pancreas grafts. A total perfusion failure is equally reliably demonstrable as in renal grafts. Quantitatively smaller perfusion alterations can be demonstrated by monitoring the course. It seems possible to differentiate the salivary edema of a rejection reaction, well known from animal experiments, with the help of other paramters (e.g. creatinine). Further clinical studies are however necessary to confirm these results. (orig.) [de

  9. Assessment of rotatory instability after anterior cruciate ligament reconstruction with a bone-patellar tendon-bone graft

    Tashiro, Yasutaka; Okazaki, Ken; Miura, Hiromasa

    2010-01-01

    Anatomically oriented anterior cruciate ligament (ACL) reconstruction has been advocated recently, but its effect on rotatory instability remains to be cleared objectively. The purpose of this study was to quantitatively evaluate rotatory instability in ACL reconstructed knees with a bone-patellar tendon-bone (BTB) graft using an open MRI system. Eighteen subjects underwent arthroscopic ACL reconstruction with a BTB graft. The tibial tunnel was placed in the center of the ACL footprint. The femoral tunnel was drilled transtibially at the 10:00 to 10:30-o'clock position for the right knees. Subjects were examined using a Slocum anterolateral rotatory instability test in open MRI. Anterior tibial translation was measured at the medial and lateral compartments by evaluating sagittal images. Anterior knee stability was evaluated using the KT-2000 arthrometer. The clinical knee function was assessed with the Lysholm and Tegner scoring scales before and after the surgery. Side-to-side differences of anterolateral tibial translation was 0.1 mm. Side-to-side difference on KT-2000 arthrometer measurement was 1.8 mm. The Lysholm score improved to 96 and the latest Tegner score reached substantially the preinjury level. ACL reconstruction with a BTB graft was successful in restoring rotatory stability as well as anterior stability and knee function. (author)

  10. Hypoglossal-facial-jump-anastomosis without an interposition nerve graft.

    Beutner, Dirk; Luers, Jan C; Grosheva, Maria

    2013-10-01

    The hypoglossal-facial-anastomosis is the most often applied procedure for the reanimation of a long lasting peripheral facial nerve paralysis. The use of an interposition graft and its end-to-side anastomosis to the hypoglossal nerve allows the preservation of the tongue function and also requires two anastomosis sites and a free second donor nerve. We describe the modified technique of the hypoglossal-facial-jump-anastomosis without an interposition and present the first results. Retrospective case study. We performed the facial nerve reconstruction in five patients. The indication for the surgery was a long-standing facial paralysis with preserved portion distal to geniculate ganglion, absent voluntary activity in the needle facial electromyography, and an intact bilateral hypoglossal nerve. Following mastoidectomy, the facial nerve was mobilized in the fallopian canal down to its bifurcation in the parotid gland and cut in its tympanic portion distal to the lesion. Then, a tensionless end-to-side suture to the hypoglossal nerve was performed. The facial function was monitored up to 16 months postoperatively. The reconstruction technique succeeded in all patients: The facial function improved within the average time period of 10 months to the House-Brackmann score 3. This modified technique of the hypoglossal-facial reanimation is a valid method with good clinical results, especially in cases of a preserved intramastoidal facial nerve. Level 4. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  11. Stent graft placement for dysfunctional arteriovenous grafts

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

    2015-07-15

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

  12. From Side to Side: Symmetry in Handaxes in the British Lower and Middle Palaeolithic

    McNabb, John; Cole, James; Hoggard, Christian Steven

    2018-01-01

    on a large body of British Acheulean handaxes. Our second aim is to present a relatively simple and low tech methodology for the analysis of handaxes and their symmetry that is widely available and does not require expensive equipment or specialist software/technical knowledge. It works from orthogonal...

  13. Side-to-side asymmetry in absolute and relative muscle thickness

    The abdominal musculature plays a protective role against lower-back injury. ... the effects of training could be evaluated. ... done at rest, during an abdominal drawing-in manoeuvre (ADIM) and the active ... Ferreira et al.[3] found .... medium pace bowlers aged 18 - 26 years participated in the study ..... without low back pain.

  14. Bone Graft Alternatives

    ... Spine Treatment Spondylolisthesis BLOG FIND A SPECIALIST Treatments Bone Graft Alternatives Patient Education Committee Patient Education Committee ... procedure such as spinal fusion. What Types of Bone Grafts are There? Bone grafts that are transplanted ...

  15. Bone grafting: An overview

    D. O. Joshi

    2010-08-01

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

  16. End-to-side nerve suture – a technique to repair peripheral nerve ...

    Lateral sprouting from an intact nerve into an attached nerve does occur, and functional recovery (sensory and motor) has been demonstrated. We have demonstrated conclusively that ETSNS in the human is a viable option in treating peripheral nerve injuries, including injuries to the brachial plexus. Among the many ...

  17. Downstream anastomotic hyperplasia. A mechanism of failure in Dacron arterial grafts.

    LoGerfo, F W; Quist, W C; Nowak, M D; Crawshaw, H M; Haudenschild, C C

    1983-01-01

    The precise location and progression of anastomotic hyperplasia and its possible relationship to flow disturbances was investigated in femoro-femoral Dacron grafts in 28 dogs. In 13 grafts, the outflow from the end-to-side downstream anastomosis was bidirectional (BDO), and in 15 it was unidirectional (UDO) (distally). Grafts were electively removed at intervals of two to 196 days or at the time of thrombosis. Each anastomosis and adjacent artery was perfusion-fixed and sectioned sagittally. The mean sagittal section was projected onto a digitized pad, and the total area of hyperplasia internal to the arterial internal elastic lamina and within the adjacent graft was integrated by computer. The location of the hyperplasia was compared with previously established sites of flow separation and stagnation. The observation was made that hyperplasia is significantly greater at the downstream, as compared with the upstream, anastomosis in both groups (BDO = p less than 0.001 and UDO = p less than 0.001) (analysis of variance for independent groups). Furthermore, this downstream hyperplasia was progressive with time (BDO p less than 0.01) (UDO p less than 0.01); Spearman Rank Correlation. There was no significant increase in the extent of downstream hyperplasia where flow separation was known to be greater (BDO). Five grafts failed (three BDO, two UDO), as a result of complete occlusion of the downstream anastomosis by fibrous hyperplasia. Transmission electron microscopy showed the hyperplasia to consist of collagen-producing smooth muscle cells. Anastomotic hyperplasia is significantly greater at the downstream anastomosis, is progressive with time, and is the primary cause of failure of Dacron arterial grafts in this model. Quantitative analysis of downstream anastomotic hyperplasia may be a valuable measure of the biocompatibility of Dacron grafts. Images Fig. 2. Fig. 3. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:6219641

  18. Grafting and curing

    Garnett, J.L.; Loo-Teck Ng; Visay Viengkhou

    1998-01-01

    Progress in radiation grafting and curing is briefly reviewed. The two processes are shown to be mechanistically related. The parameters influencing yields are examined particularly for grafting. For ionising radiation grafting systems (EB and gamma ray) these include solvents, substrate and monomer structure, dose and dose-rate, temperature and more recently role of additives. In addition, for UV grafting, the significance of photoinitiators is discussed. Current applications of radiation grafting and curing are outlined. The recent development of photoinitiator free grafting and curing is examined as well as the potential for the new excimer laser sources. The future application of both grafting and curing is considered, especially the significance of the occurrence of concurrent grafting during cure and its relevance in environmental considerations

  19. Skin graft - slideshow

    ... this page: //medlineplus.gov/ency/presentations/100100.htm Skin graft - series—Normal anatomy To use the sharing features ... entire body, and acts as a protective barrier. Skin grafts may be recommended for: Extensive wounds Burns Specific ...

  20. Bone grafts in dentistry

    Prasanna Kumar

    2013-01-01

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

  1. Immunohistochemical study of jejunal graft mucosa cell populations during the initial adaptation phase in the host body in rats.

    Tóth, Stefan; Jonecová, Zuzana; Varga, Ján; Staško, Pavel; Kovalčinová, Barbora; Maretta, Milan; Leško, Dušan; Veselá, Jarmila

    2013-10-01

    The character of the changes in cell populations within the jejunal graft mucosa during the initial adaptation phase in the host body was investigated. 24 adult male Wistar rats underwent intestinal heterotopic allotransplantation. Aorto-aortal and porto-caval anastomoses were performed using the end-to-side microsurgery technique. Graft tissues were compared to the intestinal tissues of the recipients. This study demonstrates that: (1) Distinct injury to the graft mucosa 1h after transplantation was accompanied by significant reduction in numbers of epithelial secretory cell populations. The injury was more intense in the mesenteric portion. Six hours after transplantation the graft mucosa was covered by a continuous epithelium, but the number of goblet and Paneth cells was found to be less than 30% of that in the recipient epithelium. (2) In comparison with recipients, myeloperoxidase-positive cell numbers increased significantly in the graft mucosa 1 h after transplantation. In the epithelial layer, denudation and destruction of villi was associated with a significant reduction in intraepithelial lymphocyte numbers. A significant decrease in mucosal mast cell numbers was detected 6 h after transplantation. They attained only 10% of the number found in the recipients. (3) Time-dependent changes in the graft mucosa revealed that CD163-positive cells increased significantly in the graft mucosa during 6 h after transplantation and reached the level found in the recipients. In contrast, the myeloperoxidase-positive cell population significantly decreased in the graft mucosa within the initial 6 h. Copyright © 2013 Elsevier GmbH. All rights reserved.

  2. Osseous scintigraphy and auxiliary graft

    Khelifa, F.; Siles, S.; Puech, B.

    1992-01-01

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

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

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

    2015-01-01

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

  4. Advances in radiation grafting

    Hegazy, El-Sayed A.; AbdEl-Rehim, H.A.; Kamal, H.; Kandeel, K.A.

    2001-01-01

    Graft copolymerization is an attractive means for modifying base polymers because grafting frequently results in the superposition of properties relating to the backbone and pendent chains. Among the various methods for initiating the grafting reaction, ionizing radiation is the cleanest and most versatile method of grafting available. Ion-exchange membranes play an important role in modern technology, especially in separation and purification of materials. The search for improved membrane composition has considered almost every available polymeric material because of its great practical importance. Grafting of polymers with a mixture of monomers is important since different types of chains containing different functional groups are included. A great deal is focused on the waste treatment of heavy and toxic metals from wastewater because of the severe problems of environmental pollution. Functionalized polymers suitable for metal adsorption with their reactive functional groups such as carboxylic and pyridine groups suitable for waste treatment were prepared by radiation grafting method. More reactive chelating groups were further introduced to the grafted copolymer through its functional groups by chemical treatments with suitable reagents. The advances of radiation grafting and possible uses are briefly discussed

  5. Bone graft revascularization strategies

    Willems, W.F.

    2014-01-01

    Reconstruction of avascular necrotic bone by pedicled bone grafting is a well-known treatment with little basic research supporting its application. A new canine model was used to simulate carpal bone avascular necrosis. Pedicled bone grafting proved to increase bone remodeling and bone blood flow,

  6. Graft-Sparing Strategy for Thoracic Prosthetic Graft Infection.

    Uchino, Gaku; Yoshida, Takeshi; Kakii, Bunpachi; Furui, Masato

    2018-04-01

     Thoracic prosthetic graft infection is a rare but serious complication with no standard management. We reported our surgical experience on graft-sparing strategy for thoracic prosthetic graft infection.  This study included patients who underwent graft-sparing surgery for thoracic prosthetic graft infection at Matsubara Tokushukai Hospital in Japan from January 2000 to October 2017.  There were 17 patients included in the analyses, with a mean age at surgery of 71.0 ± 10.5 years; 11 were men. In-hospital mortality was observed in five patients (29.4%).  Graft-sparing surgery for thoracic prosthetic graft infection is an alternative option particularly for early graft infection after hemiarch replacement. Georg Thieme Verlag KG Stuttgart · New York.

  7. Anterior versus posterior approach in reconstruction of infected nonunion of the tibia using the vascularized fibular graft: potentialities and limitations.

    Amr, Sherif M; El-Mofty, Aly O; Amin, Sherif N

    2002-01-01

    The potentialities, limitations, and technical pitfalls of the vascularized fibular grafting in infected nonunions of the tibia are outlined on the basis of 14 patients approached anteriorly or posteriorly. An infected nonunion of the tibia together with a large exposed area over the shin of the tibia is better approached anteriorly. The anastomosis is placed in an end-to-end or end-to-side fashion onto the anterior tibial vessels. To locate the site of the nonunion, the tibialis anterior muscle should be retracted laterally and the proximal and distal ends of the site of the nonunion debrided up to healthy bleeding bone. All the scarred skin over the anterior tibia should be excised, because it becomes devitalized as a result of the exposure. To cover the exposed area, the fibula has to be harvested with a large skin paddle, incorporating the first septocutaneous branch originating from the peroneal vessels before they gain the upper end of the flexor hallucis longus muscle. A disadvantage of harvesting the free fibula together with a skin paddle is that its pedicle is short. The skin paddle lies at the antimesenteric border of the graft, the site of incising and stripping the periosteum. In addition, it has to be sutured to the skin at the recipient site, so the soft tissues (together with the peroneal vessels), cannot be stripped off the graft to prolong its pedicle. Vein grafts should be resorted to, if the pedicle does not reach a healthy segment of the anterior tibial vessels. Defects with limited exposed areas of skin, especially in questionable patency of the vessels of the leg, require primarily a fibula with a long pedicle that could easily reach the popliteal vessels and are thus better approached posteriorly. In this approach, the site of the nonunion is exposed medial to the flexor digitorum muscle and the proximal and distal ends of the site of the nonunion debrided up to healthy bleeding bone. No attempt should be made to strip the scarred skin off

  8. Arteriovenous shunt graft ulceration with sinus and graft epithelialization

    Pooja Singhal

    2015-03-01

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

  9. Haemodynamics in axillobifemoral bypass grafts

    C.H. Wittens

    1992-01-01

    textabstractThis thesis is based on four publications on the subject of graft configuration and haemodynamics in axillobifemoral bypass grafts: 1. A clinical evaluation of 17 patients with axillobifemoral bypass graft operations, performed for various indications. Two important observations were

  10. Primary renal graft thrombosis

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

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

  11. Aortic Graft Infection Secondary to Iatrogenic Transcolonic Graft Malposition.

    Blank, Jacqueline J; Rothstein, Abby E; Lee, Cheong Jun; Malinowski, Michael J; Lewis, Brian D; Ridolfi, Timothy J; Otterson, Mary F

    2018-01-01

    Aortic graft infections are a rare but devastating complication of aortic revascularization. Often infections occur due to contamination at the time of surgery. Iatrogenic misplacement of the limbs of an aortobifemoral graft is exceedingly rare, and principles of evaluation and treatment are not well defined. We report 2 cases of aortobifemoral bypass graft malposition through the colon. Case 1 is a 54-year-old male who underwent aortobifemoral bypass grafting for acute limb ischemia. He had previously undergone a partial sigmoid colectomy for diverticulitis. Approximately 6 months after vascular surgery, he presented with an occult graft infection. Preoperative imaging and intraoperative findings were consistent with graft placement through the sigmoid colon. Case 2 is a 60-year-old male who underwent aortobifemoral bypass grafting due to a nonhealing wound after toe amputation. His postoperative course was complicated by pneumonia, bacteremia thought to be secondary to the pneumonia, general malaise, and persistent fevers. Approximately 10 weeks after the vascular surgery, he presented with imaging and intraoperative findings of graft malposition through the cecum. Aortic graft infection is usually caused by surgical contamination and presents as an indolent infection. Case 1 presented as such; Case 2 presented more acutely. Both grafts were iatrogenically misplaced through the colon at the index operation. The patients underwent extra-anatomic bypass and graft explantation and subsequently recovered.

  12. Modified end-to-side double-layer open pancreaticogastrostomy after Whipple procedure: surgical tips for a safe anastomosis.

    Dalla Valle, Raffaele; Rossini, Matteo; Lamecchi, Laura; Iaria, Maurizio

    2018-03-01

    Pancreatic fistula (PF) remains the Achilles' heel of pancreaticoduodenectomy (PD). Pancreaticogastrostomy (PG) appears to be associated with a lower risk of postoperative leak according to recent evidence. We started to fashion PG, especially in soft pancreas, modifying the original technique described by Bassi. At our institution, 105 PD procedures were carried out from January 2011 to December 2016; pancreatic-enteric continuity was restored by PG in 35 cases. Superior mesenteric/portal vein resection/reconstruction was necessary in three patients. A total of 34/35 patients underwent PG with an open anterior gastrostomy approach. Briefly, our double-layer PG anastomosis (illustrated by a video) starts with a posterior row of interrupted absorbable 4/0 monofilament sutures including the gastric serosa and the pancreatic capsule. It is essential to mobilize the left pancreas for 4-5 cm and to shape the posterior gastrostomy shorter than the pancreatic stump. After a wide anterior auxiliary gastrostomy the pancreas is invaginated into the stomach and an interrupted row of sutures between the posterior gastric wall (full-thickness) and the body of the pancreatic stump is fashioned. The anterior gastrostomy is closed with an absorbable running suture. Finally, a further layer of sutures is applied over the posterior suture line between the gastric serosa and the pancreatic capsule. The 90-day postoperative mortality was nihil. No biliary leakage was detected and the overall PF rate was 11.4% (4/35) according to the ISGPF study group. Only one patient suffered a grade B PF (in this case, PG was carried out only through a posterior gastrostomy), whereas three patients had a minor (grade A) PF. Our modified PG proved to be safe and easy to perform, while it carried excellent outcomes even in the setting of soft pancreas. Despite the limited number of cases, such modified PG appears promising, particularly for pancreatic remnants at higher risk of PF.

  13. Vein grafting in fingertip replantations.

    Yan, Hede; Jackson, William D; Songcharoen, Somjade; Akdemir, Ovunc; Li, Zhijie; Chen, Xinglong; Jiang, Liangfu; Gao, Weiyang

    2009-01-01

    In this retrospective study, the survival rates of fingertip replantation with and without vein grafting were evaluated along with their postoperative functional and cosmetic results. One hundred twenty-one-fingertip amputations were performed in 103 patients between September 2002 and July 2007. Thirty-four amputated fingertips were replanted without vein grafting, while 87 amputated fingertips were replanted with vein grafting for arterial and/or venous repairs. The overall survival rates of the replantations with and without vein grafting were 90% (78/87) and 85% (29/34), respectively. The survival rates were 88% (36/41) with venous repair, 93% (25/27) with arterial repair, and 89% (17/19) with both. Nineteen patients without vein grafting and 48 patients with vein grafting had a follow-up period of more than one year. Good cosmetic and functional outcomes were observed in both groups of patients. The results show that vein grafting is a reliable technique in fingertip replantations, showing no significant difference (P > 0.05) in survival between those with and without vein grafting. Furthermore, no significant difference (P > 0.05) in survival was found between cases with vein grafts for arterial and/or venous repairs. In fingertip replantations with vein grafting, favorable functional and esthetic results can be achieved without sacrificing replantation survival. (c) 2009 Wiley-Liss, Inc.

  14. Vascular graft infections with Mycoplasma

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

    1995-01-01

    laboratory techniques, the percentage of culture-negative yet grossly infected vascular grafts seems to be increasing and is not adequately explained by the prior use of antibiotics. We have recently reported the first case of aortic graft infection with Mycoplasma. We therefore suggest the hypothesis...... that the large number of culture-negative yet grossly infected vascular grafts may be due to Mycoplasma infection not detected with conventional laboratory technique....

  15. Environmental application of radiation grafting

    Tamada, Masao

    2007-01-01

    Adsorbent having high selectivity against a certain metal ion was synthesized by means of radiation-induced graft polymerization for the purpose of environmental application. The resulting adsorbents were utilized for the removal of toxic metal from scallop waste and the collection of uranium from seawater. As a novel application of grafting, the biodegradability of poly-hydroxybutylate was controlled by grafting. The biodegradability could be depressed by the graft chain and then recovered by external stimuli such as thermal and chemical treatments. (author)

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

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

    2014-12-01

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

  17. Coronary artery bypass grafting without cardiopulmonary bypass and without interruption of native coronary flow using a novel anastomosis site restraining device ("Octopus").

    Borst, C; Jansen, E W; Tulleken, C A; Gründeman, P F; Mansvelt Beck, H J; van Dongen, J W; Hodde, K C; Bredée, J J

    1996-05-01

    This study assessed the feasibility of coronary artery bypass grafting on the beating heart without interruption of native coronary blood flow using a novel anastomosis site restraining device. Recently, an end-to-side bypass technique was described that does not require interruption of flow in the recipient artery. By means of a suction device ("Octopus"), in 31 pigs the epicardium was grasped and immobilized through an arm contraption fixed to the operating table. In the first 15 consecutive pigs (study I), the two-dimensional motion of an epicardial beacon was monitored. In 16 subsequent pigs (study II), an internal mammary artery was grafted under the microscope in two steps to a proximal coronary artery segment, without cardiopulmonary bypass. First, the internal mammary artery was sutured end-to-side to the outside of the coronary artery. Secondly, an orifice was punched in the partitioning coronary wall by an excimer laser catheter introduced through a temporary side-branch of the internal mammary artery. Study II: During 43 suction periods in four anastomosis areas, immobilization was achieved for 15 to 169 min (>30 h in total) in 13 open- and 9 closed-chest procedures without hemodynamic deterioration. The area circumscribed by the edges of the beacon trajectory (area in which the anastomosis is to be tracked) was reduced from 73.0 +/- 43.0 mm(2) (mean +/- SD) to 1.3 +/- 0.5 mm(2) (p<0.001) in the open-chest and to 0.2 +/- 0.2 mm(2) in the closed-chest procedure. At 6 weeks, no myocardial or coronary suction lesions were found. Study II: Nonocclusive anastomosis surgery required 25 +/- 3 min. No leakage, serious arrhythmias, graft closure or hemodynamic deterioration occurred during the procedure or for 2 h after ligating the coronary artery proximally. At 6 weeks, all seven grafts were patent. Coronary bypass on the beating heart without interruption of coronary flow is feasible. In both open- and in closed-chest procedures, the "Octopus" reduced

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

    2012-01-01

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

  19. SOME TECHNIQUES IN CORNEAL GRAFTING

    1971-04-10

    Apr 10, 1971 ... current herpes corneae. The visual acuity was less than. 6/60. The left eye had had a central nebula since child- hood and was deemed amblyopic. Six weeks after a 7 x 0·3 mm lamellar graft in the right eye was placed, ulceration occurred in the graft junction. A total thin conjunctival flap was sutured over.

  20. Polyether/Polyester Graft Copolymers

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

    1986-01-01

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

  1. Radiation grafting on natural films

    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.

  2. [Reconstruction of the hypopharynx and cervical esophagus using a free jejunal graft].

    Pesko, P; Bumbasirević, M; Knezević, J; Dunjić, M; Djukić, V; Simić, A; Stojakov, D; Sabljak, P; Bjelović, M; Janković, Z; Micev, M; Saranović, D

    2000-01-01

    Extensive malignant tumors of the hypopharynx and cervical esophagus continue to challenge surgeons in respect to both type and extent of resection as well as type of reconstruction. In the period between November 1st, 1996 and November 1st, 1998, at our Department, five patients have been operated due to squamocellular carcinoma of the hypopharynx using a free jejunal graft reconstruction method. The first free jejunal graft operation due to hypopharyngeal carcinoma, at the same time the first operation of this kind ever done in our Country, was performed on November 13th, 1998. There were 4 female and one male patient, average age 47.75 years. Disfagia for solid foods was a leading symptom in all patients (mean duration of 3.5 months) and was always accompanied with weight loss (average of 8 kg for two months). In all patients barium swallow, endoscopy, CT as well as intraoperative endoscopy was performed. Radical surgical procedure was always accompanied with the bilateral modified lympf node neck dissection. As a arterial donor vessel superior thyroid artery was used in all patients. As a venous drainage in three patients a external jugular vein was used and in two facial vein. Reconstruction using a free jejunal graft of approximately 25 cm long was performed in all patients creating upper, oropharingeal, anastomosis end to side and distal, esophageal, end to end (in only one patients side to end) using 3/0 apsorbable sutures. Mean duration of the operation was six hours. The postoperative course in all patients was uneventful. On the 9th postoperative day gastrografin and three days later barium swallow radiography was performed as a standard control study. Regular check ups were done on three, six, nine months, year and two years. On all controls all patients were symptom free and feeling well. It is our opinion that in the patients with isolated carcinoma of the hypopharynx due to low morbidity and mortality rate, free jejunal graft method is the surgical

  3. Graft intolerance syndrome requiring graft nephrectomy after late kidney graft failure: can it be predicted? A retrospective cohort study.

    Bunthof, Kim L W; Verhoeks, Carmen M; van den Brand, Jan A J G; Hilbrands, Luuk B

    2018-02-01

    Graft nephrectomy is recommended in case of early graft failure. When the graft fails more than 3-6 months after transplantation, it is current practice to follow a wait-and-see policy. A common indication for graft removal is the graft intolerance syndrome. We aimed to create a risk prediction model for the occurrence of graft intolerance resulting in graft nephrectomy. We collected data of kidney transplantations performed in our center between 1980 and 2010 that failed at least 6 months after transplantation. We evaluated the association between baseline characteristics and the occurrence of graft nephrectomy because of graft intolerance using a competing risk regression model. Prognostic factors were included in a multivariate prediction model. In- and exclusion criteria were met in 288 cases. In 48 patients, the graft was removed because of graft intolerance. Donor age, the number of rejections, and shorter graft survival were predictive factors for graft nephrectomy because of the graft intolerance syndrome. These factors were included in a prediction rule. Using donor age, graft survival, and the number of rejections, clinicians can predict the need for graft nephrectomy with a reasonable accuracy. © 2017 Steunstichting ESOT.

  4. Cartilage grafting in nasal reconstruction.

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

    2011-02-01

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

  5. Inheritance of graft compatibility in Douglas fir.

    D.L. Copes

    1973-01-01

    Graft compatibility of genetically related and unrelated rootstock-scion combinations was compared. Scion clones were 75% compatible when grafted on half-related rootstocks but only 56% compatible when grafted on unrelated rootstocks. Most variance associated with graft incompatibility in Douglas-fir appears to be caused by multiple genes.

  6. Graft union formation in Douglas-fir.

    D.L. Copes

    1969-01-01

    Greenhouse-grown Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) graft unions were examined between 2 and 84 days after grafting. Room temperature was maintained at 60-70 F throughout the growing season. In most respects grafts of Douglas-fir followed development patterns previously reported for spruce and pine grafts, but specific differences...

  7. Fat Grafting for Facial Filling and Regeneration.

    Coleman, Sydney R; Katzel, Evan B

    2015-07-01

    Plastic surgeons have come to realize that fat grafting can rejuvenate an aging face by restoring or creating fullness. However, fat grafting does much more than simply add volume. Grafted fat can transform or repair the tissues into which it is placed. Historically, surgeons have hesitated to embrace the rejuvenating potential of fat grafting because of poor graft take, fat necrosis, and inconsistent outcomes. This article describes fat grafting techniques and practices to assist readers in successful harvesting, processing, and placement of fat for optimal graft retention and facial esthetic outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Design of a Sapling Branch Grafting Robot

    Qun Sun

    2014-01-01

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

  9. Hydrophilic/hydrophobic character of grafted cellulose

    Takacs, E., E-mail: takacs@iki.kfki.h [Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary); Wojnarovits, L. [Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary); Borsa, J. [Budapest University of Technology and Economics (Hungary); Racz, I. [Bay Zoltan Institute for Materials Science and Technology, Budapest (Hungary)

    2010-04-15

    Vinyl monomers with long paraffin chains were grafted onto two kinds of cellulose (cotton and cotton linter) by direct irradiation grafting technique. The effect of dose, monomer structure and concentration, as well as homopolymer suppressor (styrene) concentration on the grafting yield was studied and the optimal grafting conditions were established. Grafting decreased the swelling of the samples in water and increased their polymer compatibility in polypropylene matrix.

  10. Bioresorbable pins and interference screws for fixation of hamstring tendon grafts in anterior cruciate ligament reconstruction surgery: a randomized controlled trial.

    Stengel, Dirk; Casper, Dirk; Bauwens, Kai; Ekkernkamp, Axel; Wich, Michael

    2009-09-01

    Biodegradable cross-pins have been shown to provide higher failure loads than do screws for fixation of hamstring tendons under laboratory conditions. To compare the clinical results of biodegradable pins (RigidFix) and interference screws (BioCryl) for fixation of hamstring grafts in arthroscopically assisted anterior cruciate ligament reconstruction. Study Design Randomized controlled trial; Level of evidence, 1. To test the hypothesis of a difference of 1.0 +/- 1.2 mm in anterior knee laxity between the two fixation options, 54 patients were randomly assigned to groups via a block randomization scheme and sealed envelopes. All patients underwent standardized hamstring graft reconstruction and had similar postoperative aftercare by an accelerated rehabilitation protocol. Measures assessed at baseline and after 1 and 2 years of follow-up included (1) the side-to-side difference in anterior laxity (KT-1000 arthrometer), (2) Short Form 36 physical and mental component scores, and (3) the International Knee Documentation Committee form scores. After 1 and 2 years, 26 and 21 patients in the BioCryl group and 28 and 24 patients in the RigidFix group were available for follow-up examination. No significant difference was noted in instrumented anterior translation between BioCryl and RigidFix fixation: 1 year, 0.11 (95% CI, -0.60 to 0.82; P = .7537); 2 years, 0.33 (95% CI, -0.43 to 1.08 mm; P = .3849). Also, there were no significant differences in the mean physical and mental component scores and International Knee Documentation Committee form scores and in overall complication and surgical revision rates. A pin dislocation was classified as the sole procedure-specific serious adverse event. Bioresorbable pins do not provide better clinical results than do resorbable interference screws for hamstring graft fixation in anterior cruciate ligament reconstruction surgery.

  11. Air Pump-Assisted Graft Centration, Graft Edge Unfolding, and Graft Uncreasing in Young Donor Graft Pre-Descemet Endothelial Keratoplasty.

    Jacob, Soosan; Narasimhan, Smita; Agarwal, Amar; Agarwal, Athiya; A I, Saijimol

    2017-08-01

    To assess an air pump-assisted technique for graft centration, graft edge unfolding, and graft uncreasing while performing pre-Descemet endothelial keratoplasty (PDEK) using young donor grafts. Continuous pressurized air infusion was used for graft centration, graft edge unfolding, and graft unwrinkling. Ten eyes of 10 patients underwent PDEK with donors aged below 40 years. In all eyes, the donor scrolled into tight scrolls. In all cases, the air pump-assisted technique was effective in positioning and centering the graft accurately and in straightening infolded graft edges and smoothing out graft creases and wrinkles. Endothelial cell loss was 38.6%. Postoperative best-corrected visual acuity at 6 months was 0.66 ± 0.25 in decimal equivalent. Continuous pressurized air infusion acted as a third hand providing a continuous pressure head that supported the graft and prevented graft dislocation as well as anterior chamber collapse during intraocular maneuvering. Adequate maneuvering space was available in all cases, and bleeding, if any, was tamponaded successfully in all cases. Although very young donor grafts may be used for PDEK, they are difficult to center and unroll completely before floating against host stroma. An air pump-assisted technique using continuous pressurized air infusion allows successful final graft positioning even with very young donor corneas. It thus makes surgery easier as several key steps are made easier to handle. It additionally helps in tamponading hemorrhage during peripheral iridectomy, increasing surgical space, preventing fluctuations in the anterior chamber depth, and promoting graft adherence.

  12. FAS grafted superhydrophobic ceramic membrane

    Lu Jun [School of Material Science and Engineering, Jingdezhen Ceramic Institute, 333001 Jingdezhen (China); Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, CAS, 1295 DingXi Road, Shanghai 200050 (China); Yu Yun, E-mail: yunyush@mail.sic.ac.cn [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, CAS, 1295 DingXi Road, Shanghai 200050 (China); Zhou Jianer [School of Material Science and Engineering, Jingdezhen Ceramic Institute, 333001 Jingdezhen (China); Song Lixin; Hu Xingfang [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, CAS, 1295 DingXi Road, Shanghai 200050 (China); Larbot, Andre [Institut Europeen des Membranes, UMR 5635-CNRS, ENSCM, UMII, 1919 Route de Mende 34293, Montpellier Cedex 5 (France)

    2009-08-30

    The hydrophobic properties of {gamma}-Al{sub 2}O{sub 3} membrane have been obtained by grafting fluoroalkylsilane (FAS) on the surface of the membrane. The following grafting parameters were studied: the eroding time of the original membrane, the grafting time, the concentration of FAS solution and the multiplicity of grafting. Hydrophobicity of the membranes was characterized by contact angle (CA) measurement. The thermogravimetric analysis (TGA) was used to investigate the weight loss process (25-800 deg. C) of the fluoroalkylsilane grafted on Al{sub 2}O{sub 3} powders under different grafting conditions. The morphologies of the membranes modified under different parameters were examined by field emission scanning electron microscopy (FE-SEM) and the surface roughness (Ra) was measured using white light interferometers. A needle-like structure was observed on the membrane surface after modification, which causes the change of Ra. On the results above, we speculated a model to describe the reaction between FAS and {gamma}-Al{sub 2}O{sub 3} membrane surface as well as the formed surface morphology.

  13. FAS grafted superhydrophobic ceramic membrane

    Lu, Jun; Yu, Yun; Zhou, Jianer; Song, Lixin; Hu, Xingfang; Larbot, Andre

    2009-08-01

    The hydrophobic properties of γ-Al 2O 3 membrane have been obtained by grafting fluoroalkylsilane (FAS) on the surface of the membrane. The following grafting parameters were studied: the eroding time of the original membrane, the grafting time, the concentration of FAS solution and the multiplicity of grafting. Hydrophobicity of the membranes was characterized by contact angle (CA) measurement. The thermogravimetric analysis (TGA) was used to investigate the weight loss process (25-800 °C) of the fluoroalkylsilane grafted on Al 2O 3 powders under different grafting conditions. The morphologies of the membranes modified under different parameters were examined by field emission scanning electron microscopy (FE-SEM) and the surface roughness (Ra) was measured using white light interferometers. A needle-like structure was observed on the membrane surface after modification, which causes the change of Ra. On the results above, we speculated a model to describe the reaction between FAS and γ-Al 2O 3 membrane surface as well as the formed surface morphology.

  14. Interventions in Infrainguinal Bypass Grafts

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

    2006-01-01

    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

  15. Radiation grafting on natural films

    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. - Highlights: • Irradiation of zein

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

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

    2017-09-01

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

  17. Kinetics of vein graft hyperplasia

    Zwolak, R.M.; Adams, M.C.; Clowes, A.W.

    1986-01-01

    Human aortocoronary vein grafts fail due to accelerated occlusive disease. The possibility that this is related to cellular hyperplasia was investigated in a rabbit model where kinetics of vein graft thickening, endothelial (EC) repair, and smooth muscle cell (SMC) proliferation were measured from 2 days to 24 weeks after implanting jugular vein segments in the carotid artery. Immediately after graft placement focal EC denudation was observed. These defects were repaired within 1 week and did not recur. By 4 weeks intimal area had increased 30 fold from 0.028 +/- 0.004 to 0.705 +/- 0.021 mm 2 , and a 24 weeks was 0.93 +/- 0.21 mm 2 . This response did not produce a reduction in graft lumen area. EC and SMC thymidine-labeling index were measured by en face and cross-section autoradiography after injection of 3 H-thymidine and perfusion fixation. Despite rapid EC surface repair EC labeling index remained elevated and only returned to normal levels at 12 weeks; SMC labeling was 10 fold greater than baseline even at 24 weeks (0.22% vs 0.02%). SMC mass demonstrated morphometrically increased between 2 and 12 weeks. Intimal thickening in vein grafts is due to SMC proliferation and develops after the EC layer has been restored. In contrast, intimal SMC proliferate in damaged arteries when the EC layer is absent and cease when the EC layer is regenerated

  18. Vascularized osseous graft for scaphoid

    Mendez Daza, Carlos Hernan; Mathoulin, Cristophe

    2004-01-01

    The most commonly used technique for treatment of pseudo-arthrosis of the scaphoid is osteo-synthesis with Kirschnet wires and cortical sponge grafts. Results reported by different teams using this procedure show no more than 90% osseous consolidation, especially in cases where vascularisation of the proximal fragment of the scaphoid is compromised. Here we present a series of ten cases of pseudo-arthrosis of the scaphoid, treated using a new surgical technique involving a vascularized osseous graft of the distal radius. Using this procedure we obtained 100% consolidation, with no complications either during the procedure or immediately post-operatively. Patients returned to work in week 15 on average. In 4 cases we observed discomfort in the area of the scar, which was successfully treated using local cortisone injection. The results obtained are very similar to those seen in the literature on the different techniques for vascularized osseous grafts for pseudo-arthrosis of the scaphoid

  19. Grafted SiC nanocrystals

    Saini, Isha; Sharma, Annu; Dhiman, Rajnish

    2017-01-01

    ), raman spectroscopy and X-ray diffraction (XRD) measurements. UV–Visible absorption spectroscopy was used to study optical properties such as optical energy gap (Eg), Urbach's energy (Eu), refractive index (n), real (ε1) and imaginary (ε2) parts of dielectric constant of PVA as well as PVA......Polyvinyl alcohol (PVA) grafted SiC (PVA-g-SiC)/PVA nanocomposite was synthesized by incorporating PVA grafted silicon carbide (SiC) nanocrystals inside PVA matrix. In-depth structural characterization of resulting nanocomposite was carried out using fourier transform infrared spectroscopy (FTIR...

  20. Oral mucosa grafts for urethral reconstruction

    reports reveal that split and full thickness skin grafts from the scrotum, penis, extragenital sites (ureter, saphenous .... Table 1: Summary of the history of oral mucosa grafts for urethroplasty .... advised that care should be taken when suturing the.

  1. Postoperative radiographic evaluation of vascularized fibular grafts

    Manaster, B.J.; Coleman, D.A.; Bell, D.A.

    1989-01-01

    This paper reports on thirty-five patients with free vascularized fibular grafts examined postoperatively with plain radiography. Early graft incorporation is seen as a fuzziness of the cortex at the site of its insertion into the host bone. Causes of failure in grafting for bone defects include graft fracture, hardware failure, and infection. A high percentage of complications or at least delayed unions occurred when vascularized fibular grafts were used to fill defects in the lower extremity. Conversely, upper extremity defects bridged by vascularized grafts heal quickly and hypertrophy. Vascularized grafts placed in the femoral head and neck for a vascular necrosis incorporate early on their superior aspect. The osseous tunnel in which they are placed is normally wider than the graft and often becomes sclerotic; this appearance does not represent nonunion

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

    Gao, H; Sandermann, J; Prag, J

    2010-01-01

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

  3. Evaluation of Replacement Grafts and Punch Grafts in the Treatment of Vitiligo

    Singh Ajit Kumar

    1980-01-01

    Full Text Available Thirtycasesof vitiligo eachwithminimum of two lesions undent replacement graft and multiple punch grafts in one lesion each. Complications observed at the recipient site like infection and raised nigosed surface were significantly more in replacement grafts. Hypopigmentation of the graft was significantly more when the disease was progressive.

  4. Graft infections after surgical aortic reconstructions

    Berger, P.

    2015-01-01

    Prosthetic vascular grafts are frequently used to reconstruct (part) of the aorta. Every surgical procedure caries a certain risk for infection and when a prosthetic aortic graft is implanted, this may lead to an aortic graft infection (AGI). Endovascular techniques have gradually replaced open

  5. Side-to-side 3D coverage path planning approach for agricultural robots to minimize skip/overlap areas between swaths

    Hameed, Ibrahim; la Cour-Harbo, Anders; Osen, O. L.

    2016-01-01

    Automated path planning is important for the automation and optimization of field operations. It can provide the waypoints required for guidance, navigation and control of agricultural robots and autonomous tractors throughout the execution of these field operations. In agriculture, field...... operations are usually repeated in the same field and from year to year as well, therefore, it should be carried out in a manner that minimizes environmental impact and cost taking into account the topographic land features. Current 3D terrain field coverage path planning algorithms are simply 2D coverage...

  6. The caudal septum replacement graft.

    Foda, Hossam M T

    2008-01-01

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

  7. ACL Graft Healing and Biologics

    Muller, Bart; Bowman, Karl F.; Bedi, Asheesh

    2013-01-01

    Operative reconstruction of a torn anterior cruciate ligament (ACL) has become the most broadly accepted treatment. An important, but underreported, outcome of ACL reconstruction is graft failure, which poses a challenge for the orthopedic surgeon. An understanding of the tendon-bone healing and the

  8. Polyether-polyester graft copolymer

    Bell, Vernon L. (Inventor)

    1987-01-01

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

  9. Homogeneous cation exchange membrane by radiation grafting

    Kolhe, Shailesh M.; G, Agathian; Ashok Kumar

    2001-01-01

    Preparation of a strong cation exchange membrane by radiation grafting of styrene on to polyethylene (LDPE) film by mutual irradiation technique in the presence of air followed by sulfonation is described. The grafting has been carried out in the presence of air and without any additive. Low dose rate has been seen to facilitate the grafting. Further higher the grafting percentage more is the exchange capacity. The addition of a swelling agent during the sulfonation helped in achieving the high exchange capacity. The TGA-MASS analysis confirmed the grafting and the sulfonation. (author)

  10. Studies on radiation-induced graft polymerization

    Omichi, Hideki

    1978-09-01

    Radiation-induced graft polymerization is used extensively to improve physical properties of polymers, but few processes are now commercialized. The reason for this is partly inadequate basic research on the reaction and partly the difficulty in developing the grafting process with large radiation source. Firstly, new techniques are proposed of studying kinetics of the graft polymerization in heterogeneous system. Based on the grafting yield, the molecular weight of graft chains, and the amount of radicals given by ESR and activation analysis, kinetic parameters are obtained and the reaction mechanism of grafting process is discussed. Secondly, the development of grafting process of poly (vinyl chloride)-butadiene is described. By study of the reaction, process design, construction and operation of the pilot plant, and economic analysis of the process, this process with 60 Co gamma ray sources is shown to be industrially promising. (author)

  11. Dynamics of bone graft healing around implants

    Narayan Venkataraman

    2015-01-01

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

  12. Septal graft in laryngeal reconstruction

    Bahannan, Abdulrahman; Slavicek, A.; Taudy, M.; Chovanec, M.

    2006-01-01

    A 62-year-old woman presented with symptoms of dyspnea. Ultrasonography and computed tomography examinations revealed mass extending from the cricoid cartilage to the left lobe of thyroid gland and thyroid cartilage. Cytology revealed possibility of cartilaginous origin, which was proven to be chondrosarcoma (Grade 1) from the biopsy specimen obtained during panendosopy. She underwent one stage radical resection and immediate reconstruction of laryngeal skeleton defect by mucocartilaginous graft from the nasal septum. Her postoperative course was optimal with preservation of the laryngeal functions. Twenty-eight months postoperatively, she had to undergo total laryngectomy as a salvage procedure for the advanced local recurrence. We report on the relatively easy technique for functional reconstruction of the large laryngeal defect with the employment cartilage graft from the nasal septum. (author)

  13. Determining the degree of grafting for poly (vinylidene fluoride) graft-copolymers using fluorine elemental analysis

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

    2011-01-01

    Acrylic acid (AAc) and styrene (St) were grafted onto poly (vinylidene fluoride) (PVDF) powder or membrane samples by pre-irradiation graft copolymerization. The grafted chains were proved by FT-IR spectroscopy analysis. The degree of grafting (DG) of the grafted PVDF was determined by fluorine elemental analysis (FEA) method, and was compared with the DGs determined by weighing method, acid-base back titration method and quantitative FT-IR method. The results show that the FEA method is accurate, convenient and universal, especially for the grafted polymer powders. (authors)

  14. [Autologous fat grafting in children].

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

    2016-10-01

    Lipofilling or fat grafting transfer is defined as a technique of filling soft tissue by autologous fat grafting. The basic principle of lipofilling is based on a harvest of adipose tissue, followed by a reinjection after treatment. Lipofilling main objective is a volume defect filling, but also improving cutaneous trophicity. Lipofilling specificities among children is mainly based on these indications. Complications of autologous fat grafting among children are the same as those in adults: we distinguish short-term complications (intraoperative and perioperative) and the medium and long-term complications. The harvesting of fat tissue is the main limiting factor of the technique, due to low percentage of body fat of children. Indications of lipofilling among children may be specific or similar to those in adults. There are two types of indications: cosmetic, in which the aim of lipofilling is correcting a defect density, acquired (iatrogenic, post-traumatic scar) or malformation (otomandibular dysplasia, craniosynostosis, Parry Romberg syndrom, Poland syndrom, pectus excavatum…). The aim of functional indications is correcting a velar insufficiency or lagophthalmos. In the paediatric sector, lipofilling has become an alternative to the conventional techniques, by its reliability, safety, reproducibility, and good results. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Bypass grafting to the anterior tibial artery.

    Armour, R H

    1976-01-01

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

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

    Raissi Kamal

    2009-12-01

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

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

    Ong, J C Y

    2012-06-01

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

  18. Current status of grafts and implants in rhinoplasty: Part II. Homologous grafts and allogenic implants.

    Sajjadian, Ali; Naghshineh, Nima; Rubinstein, Roee

    2010-03-01

    After reading this article, the participant should be able to: 1. Understand the challenges in restoring volume and structural integrity in rhinoplasty. 2. Identify the appropriate uses of various homologous grafts and allogenic implants in reconstruction, including: (a) freeze-dried acellular allogenic cadaveric dermis grafts, (b) irradiated cartilage grafts, (c) hydroxyapatite mineral matrix, (d) silicone implants, (e) high-density polyethylene implants, (f) polytetrafluoroethylene implants, and (g) injectable filler materials. 3. Identify the advantages and disadvantages of each of these biomaterials. 4. Understand the specific techniques that may aid in the use these grafts or implants. This review specifically addresses the use of homologous grafts and allogenic implants in rhinoplasty. It is important to stress that autologous materials remain the preferred graft material for use in rhinoplasty, owing to their high biocompatibility and low risk of infection and extrusion. However, concerns of donor-site morbidity, graft availability, and graft resorption have motivated the development and use of homologous and allogenic implants.

  19. Multiple arterial grafts in coronary artery bypass grafting, Sohag University Hospital's initial experience

    A.A.A. Elsayed

    2017-12-01

    Conclusions: Using multiple arterial grafts did not add a significant risk or time to the classic CABG. With accumulating evidence about better patency rate in arterial grafts, MAR is recommended especially in younger patients undergoing CABG.

  20. Graft infections after surgical aortic reconstructions

    Berger, P.

    2015-01-01

    Prosthetic vascular grafts are frequently used to reconstruct (part) of the aorta. Every surgical procedure caries a certain risk for infection and when a prosthetic aortic graft is implanted, this may lead to an aortic graft infection (AGI). Endovascular techniques have gradually replaced open surgical reconstructions as first line of treatment for aorto-iliac diseases. Nowadays, open reconstructions are primarily reserved for patients unsuitable for endovascular reconstructions or for redo ...

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

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

    2015-08-15

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

  2. The autologus graft of epithelial tissue culture

    Minaee B

    1999-08-01

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

  3. Nuclear accidents and bone marrow graft

    Bernard, J.

    1988-01-01

    In case of serious contamination, the only efficacious treatment is the bone marrow grafts. The graft types and conditions have been explained. To restrict the nuclear accidents consequences, it is recommended to: - take osseous medulla of the personnel exposed to radiations and preserve it , that permits to carry out rapidly the auto-graft in case of accidents; - determine, beforehand, the HLA group of the personnel; - to register the voluntary donors names and addresses, and their HLA group, that permits to find easily a compatible donar in case of allo-graft. (author)

  4. Lipoplex gene transfer of inducible nitric oxide synthase inhibits the reactive intimal hyperplasia after expanded polytetrafluoroethylene bypass grafting.

    Pfeiffer, Tomas; Wallich, Martina; Sandmann, Wilhelm; Schrader, Jürgen; Gödecke, Axel

    2006-05-01

    Intimal hyperplasia (IH) is most commonly the cause of graft occlusion in infrainguinal bypass grafting for arterial occlusive disease. We investigated the influence of nitric oxide on the IH of the arterial vessel wall at the region of prosthetic bypass anastomoses. Experiments were performed in 10 Foxhound dogs. We used a technique of inducible nitric oxide synthase (iNOS) overexpression by a non-virus-mediated, liposome-based iNOS gene transfer. The plasmid pSCMV-iNOS, which drives the expression of iNOS under control of the cytomegalovirus promoter, was complexed with cationic liposomes (lipoplexes). Segments of both carotid arteries were pretreated by intramural injection of a lipoplex solution by using an infiltrator balloon catheter (Infiltrator Drug Delivery Balloon System). In each dog, iNOS was administered at one side, and a control vector (pSCMV2) was administered at the contralateral side. Carotid arteries were ligated, and bypass grafts (expanded polytetrafluoroethylene, 6-mm, ring enforced) were implanted on both sides. The proximal and distal anastomoses (end-to-side fashion; running nonabsorbable sutures) were placed in the pretreated regions. After 6 months, the prostheses were excised, and the intimal thicknesses of 50 cross sections (orcein staining) of each anastomosis were measured planimetrically. The average reduction of the neointima thickness of the iNOS side in proximal anastomoses at the prosthetic wall, suture region, and arterial wall was 43%, 52%, and 81%, respectively. In distal anastomoses, the average reduction was 40%, 47%, and 52%, respectively. All differences of neointima thickness between the iNOS and control sides were statistically significant (Wilcoxon test; P < or = .05). Inducible NOS expression is an efficient approach for inhibition of IH. In contrast to earlier studies, which investigated the efficacy of gene therapeutic NOS expression at 3 to 4 weeks after intervention, the novelty of our findings is that a single

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

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

    2013-12-15

    In order to develop a non-chemical method such as grafting effective against well-known artichoke soil borne diseases, an anatomical study of union formation in artichoke grafted onto selected wild and cultivated cardoon rootstocks, both resistant to Verticillium wilt, was performed. The cardoon accessions Belgio (cultivated cardoon) and Sardo (wild cardoon) were selected as rootstocks for grafting combinations with the artichoke cv. Romolo. Grafting experiments were carried out in the autumn and spring. The anatomical investigation of grafting union formation was conducted by scanning electron microscopy (SEM) on the grafting portions at the 3rd, 6th, 10th, 12th day after grafting. For the autumn experiment only, SEM analysis was also performed at 30 d after grafting. A high affinity between artichoke scion and cardoon rootstocks was observed, with some genotype differences in healing time between the two bionts. SEM images of scion/rootstock longitudinal sections revealed the appearance of many interconnecting structures between the two grafting components just 3d after grafting, followed by a vascular rearrangement and a callus development during graft union formation. De novo formation of many plasmodesmata between scion and rootstock confirmed their high compatibility, particularly in the globe artichoke/wild cardoon combination. Moreover, the duration of the early-stage grafting process could be influenced not only by the scion/rootstock compatibility, but also by the seasonal conditions, being favored by lower temperatures and a reduced light/dark photoperiod. Copyright © 2013 Elsevier GmbH. All rights reserved.

  6. Lymphoid Tissue Grafts in Man

    Kay, H. E.M. [Royal Marsden Hospital, Institute of Cancer Research, London (United Kingdom)

    1969-07-15

    Grafts of lymphoid tissue or of lymphoid stem cells may be appropriate in the treatment of some congenital immune deficiency disorders. The reasons for preferring tissues of foetal origin are discussed and the evidence for foetal immunocompetence is briefly summarized. Methods of storing foetal liver cells and cells or fragments of thymus are mentioned, and the organization of the Foetal Tissue Bank of the Royal Marsden Hospital is described. Clinical data from transplantation of lymphoid cells in various immune deficiency disorders are briefly presented. (author)

  7. Development of sodium alginate and konkoli gum- grafted ...

    STORAGESEVER

    2008-05-02

    May 2, 2008 ... grafted-polyacrylamide blend membrane: optimization of grafting conditions .... medium and reduce rate of termination by the coupling of the growing ... Effect of time. The time conversion curve of the graft copolymerization ...

  8. Industrial application of electron beams for grafting and vulcanization

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1994-12-31

    The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber.

  9. Industrial application of electron beams for grafting and vulcanization

    Keizo Makuuchi

    1994-01-01

    The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber

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

    Nair, Nitish; Wentzel, Nathaniel; Jayaraman, Arthi

    2011-05-21

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

  11. Improvement of polymer stability by radiation grafting

    Ranogajec, F.; Mlinac-Misak, M.

    1999-01-01

    Losses of the stabilizer due to extractability or volatility immediately affect ultimate performance of polymer product. A new approach to increase the persistence of the stabilizer in the final product is to chemically bind it to the polymer backbone. Radiation grafting or crosslinking could be an efficient method for this, when the stabilizer is polymerizable. By a mutual gamma irradiation method, photoprotector 2-hydroxy-4-(3-methacryloxy-2- hydroxy-propoxy) benzophenone (HMB) has been readily grafted to low density polyethylene (LDPE) in benzene, tetrahydrofuran and methanol solution, respectively. Surface grafting occurs in a methanol solution of stabilizer, while in benzene and tetrahydrofuran solutions of stabilizer, grafting proceeds more or less in the inner parts of the polymeric film as well. The grafted LDPE film in methanol and tetrahydrofuran (containing 1 w/w % of grafted HMB), 1 w/w % blended HMB with LDPE and nongrafted LDPE film, were all exposed to accelerated aging and natural weathering and their spectral changes, expressed by the carbonyl index, were then compared. The change of elongation at break and tensile strength were measured in the course of aging. UV stability tests on aged films and change in mechanical properties indicate a pronounced protective effect achieved by grafted stabilizer. Grafting in methanol solution appears to be an efficient photostabilization treatment and the most economical with respect to the consumption of monomer, the grafting yield being less than 0.5%. Surface grafting is an efficient photostabilization method since grafted stabilizer is chemically bound to a polymeric surface and in this way the problem of evaporation of blended stabilizers during the prolonged use of polymeric materials is eliminated. (author)

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

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

    2007-06-01

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

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

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

    2007-01-01

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

  14. Nanofat grafting under a split-thickness skin graft for problematic wound management.

    Kemaloğlu, Cemal Alper

    2016-01-01

    Obesity and certain medical disorders make the reconstruction of skin defects challenging. Different kind of procedure can be used for these defect, besides, skin grafting is one of the most common and simplest procedure. Fat grafting and stem cells which are located in the adipose tissue have been commonly used in plastic surgery for regeneration and rejuvenation purposes. To decrease graft failure rate we performed nanofat grafting under an autologous split-thickness skin graft in our patient who had a problematic wound. The case of a 35-year-old female patient with a traumatic skin defect on her left anterior crural region is described herein. After subsequent flap reconstruction, the result was disappointing and the defect size was widened. The defect was treated with combined grafting (nanofat grafting under an autologous split-thickness skin graft). At the 6 months follow-up assessment after combined grafting, the integrity of the skin graft was good with excellent pliability. Combined grafting for problematic wounds seems to be a useful technique for cases requiring reconstruction. The potential existence of stem cells may be responsible for the successful result in our patient.

  15. Emerging concepts in liver graft preservation

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

    2015-01-01

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

  16. Dynamics of solvent-free grafted nanoparticles

    Chremos, Alexandros; Panagiotopoulos, Athanassios Z.; Koch, Donald L.

    2012-01-01

    as well as grafted nanoparticles in a melt were compared to a reference system of bare (ungrafted) particles in a melt. Whereas longer chains lead to a larger hydrodynamic radius and lower relative diffusivity for grafted particles in a melt, bulk solvent

  17. The effect of monomer molecular weight on grafting reaction

    Wu Minghong; Ding Zhongli; Ma Zueteh

    1995-01-01

    In this paper, some condensed ethylene glycol acrylate monomers with different molecular weight being grafted to the PE film by means of pre-irradiation is reported. The effect of molecular weight of monomer on grafting reaction and the hydrophilicity of grafting sample have been discussed. The experimental results show: molar degrees of grafting decreased non-linearly with the increasement of molecular weight of monomer, the grafting reaction of polymer is greater effected by the swelling degree of PE film, the greater the swelling degree of grafting material, the higher the grating degree grafting is, the initial rate of grafting reaction decreased with the increasement of molecular weight of monomer. (author)

  18. Cadaveric aorta implantation for aortic graft infection.

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

    2016-01-01

    This case report describes a 73-year-old gentleman who underwent explantation of an infected prosthetic aorto-iliac graft and replacement with a cryopreserved thoracic and aorto-iliac allograft. The patient has been followed up a for more than a year after surgery and remains well. After elective tube graft repair of his abdominal aortic aneurysm (AAA) in 2003, he presented to our unit in 2012 in cardiac arrest as a result of a rupture of the distal graft suture line due to infection. After resuscitation he underwent aorto-bifemoral grafting using a cuff of the original aortic graft proximally. Distally the new graft was anastomosed to his common femoral arteries, with gentamicin beads left in situ. Post discharge the patient was kept under close surveillance with serial investigations including nuclear scanning, however it became apparent that his new graft was infected and that he would require aortic graft replacement, an operation with a mortality of at least 50%. The patient underwent the operation and findings confirmed a synthetic graft infection. This tube graft was explanted and a cryopreserved aorta was used to the refashion the abdominal aorta and its bifurcation. The operation required a return to theatre day one post operatively for a bleeding side branch, which was repaired. The patient went on to make a full recovery stepping down from the intensive therapy unit day 6 post operatively and went on to be discharged 32 days after his cryopreserved aorta implantation. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  19. Imaging features of anterior cruciate ligament reconstruction graft insufficiency

    Shang Yao; Zhang Yue; Tian Chunyan; Zheng Zhuozhao

    2011-01-01

    Objective: To investigate the imaging features of anterior cruciate ligament (ACL) graft insufficiency. Methods: X-Ray and MR imaging examinations in 24 consecutive patients who had ACL reconstructive graft insufficiency were retrospectively evaluated for tunnel position, osteoarthrosis and its related complications. Follow-up arthroscopy showed 16 graft tears and 8 graft laxities. Fisher exact test was used to compare tunnel malpositions, the proportion of graft tear on MRI and osteoarthrosis between graft tear group and graft laxity group. Results: Two malpositions of tibial tunnel and 3 malpositions of femoral tunnel were seen in graft tear group. Three-malpositions of tibial tunnel and 4 malpositions of femoral tunnel were seen in graft laxity group. The proportion of tibial or femoral malposition showed no significant difference between the two groups (P=0.289, P=0.167). In graft tear group, 15 complete graft tears were diagnosed correctly, 1 partial tear was misdiagnosed as normal on MRI. In graft laxity group, 4 grafts were diagnosed as normal and 4 were considered as graft tear on MRI. A significant difference was seen between the two groups (P=0.028) in the proportion of graft tear diagnosed on MRI. Fourteen osteoarthrosis were seen in graft tear group and 5 in graft laxity group. No significant difference was seen between the two groups (P= 0.289) in the proportion of osteoarthrosis. Conclusion: The proportions of tunnel malposition and osteoarthrosis showed no significant difference between the graft tear group and graft Laxity group. Most graft tears can be diagnosed accurately on MRI, but some cases of graft laxity may be misdiagnosed for graft tear. (authors)

  20. Chloroanthraquinone as a grafted probe molecule to investigate grafting yield on carbon powder

    Le Comte, Annaïg; Brousse, Thierry; Bélanger, Daniel

    2016-01-01

    Spontaneous grafting of chloroanthraquinone (ClAQ) groups on Black Pearls carbon by reduction of the corresponding in-situ generated diazonium cations was successfully achieved. The presence of an halogen atom on the quinone molecule allowed the use of different spectroscopic characterization techniques to determine the accurate quinone content of the modified carbon. Electrochemical characterization highlighted that the presence of chlorine atom on the grafted molecule did not affect the electrochemical response or the grafting reaction efficiency. The amount of ClAQ molecules at the carbon surface after grafting was determined by cyclic voltammetry, together with thermogravimetric analysis coupled mass spectroscopy, X-ray photoelectron spectroscopy and elemental analysis. The ClAQ mass loadings estimated from the four techniques are in very good agreement and confirm that the grafted moieties are all electrochemically active and accessible. Finally, the grafting of quinone-type molecule using the reduction of diazonium cations does not affect the electroactivity of the grafted groups and cyclic voltammetry can be considered as a reliable technique to evaluate the mass loading of grafted quinone groups on porous carbon. Thus ClAQ can be used as a grafted probe molecule to investigate grafting yield on carbon powder, and this approach can be extended to functionalized electrodes used in an increasing number of electrochemical energy storage devices.

  1. Evaluation of synthetic vascular grafts in a mouse carotid grafting model.

    Alex H P Chan

    Full Text Available Current animal models for the evaluation of synthetic grafts are lacking many of the molecular tools and transgenic studies available to other branches of biology. A mouse model of vascular grafting would allow for the study of molecular mechanisms of graft failure, including in the context of clinically relevant disease states. In this study, we comprehensively characterise a sutureless grafting model which facilitates the evaluation of synthetic grafts in the mouse carotid artery. Using conduits electrospun from polycaprolactone (PCL we show the gradual development of a significant neointima within 28 days, found to be greatest at the anastomoses. Histological analysis showed temporal increases in smooth muscle cell and collagen content within the neointima, demonstrating its maturation. Endothelialisation of the PCL grafts, assessed by scanning electron microscopy (SEM analysis and CD31 staining, was near complete within 28 days, together replicating two critical aspects of graft performance. To further demonstrate the potential of this mouse model, we used longitudinal non-invasive tracking of bone-marrow mononuclear cells from a transgenic mouse strain with a dual reporter construct encoding both luciferase and green fluorescent protein (GFP. This enabled characterisation of mononuclear cell homing and engraftment to PCL using bioluminescence imaging and histological staining over time (7, 14 and 28 days. We observed peak luminescence at 7 days post-graft implantation that persisted until sacrifice at 28 days. Collectively, we have established and characterised a high-throughput model of grafting that allows for the evaluation of key clinical drivers of graft performance.

  2. Evaluation of synthetic vascular grafts in a mouse carotid grafting model.

    Chan, Alex H P; Tan, Richard P; Michael, Praveesuda L; Lee, Bob S L; Vanags, Laura Z; Ng, Martin K C; Bursill, Christina A; Wise, Steven G

    2017-01-01

    Current animal models for the evaluation of synthetic grafts are lacking many of the molecular tools and transgenic studies available to other branches of biology. A mouse model of vascular grafting would allow for the study of molecular mechanisms of graft failure, including in the context of clinically relevant disease states. In this study, we comprehensively characterise a sutureless grafting model which facilitates the evaluation of synthetic grafts in the mouse carotid artery. Using conduits electrospun from polycaprolactone (PCL) we show the gradual development of a significant neointima within 28 days, found to be greatest at the anastomoses. Histological analysis showed temporal increases in smooth muscle cell and collagen content within the neointima, demonstrating its maturation. Endothelialisation of the PCL grafts, assessed by scanning electron microscopy (SEM) analysis and CD31 staining, was near complete within 28 days, together replicating two critical aspects of graft performance. To further demonstrate the potential of this mouse model, we used longitudinal non-invasive tracking of bone-marrow mononuclear cells from a transgenic mouse strain with a dual reporter construct encoding both luciferase and green fluorescent protein (GFP). This enabled characterisation of mononuclear cell homing and engraftment to PCL using bioluminescence imaging and histological staining over time (7, 14 and 28 days). We observed peak luminescence at 7 days post-graft implantation that persisted until sacrifice at 28 days. Collectively, we have established and characterised a high-throughput model of grafting that allows for the evaluation of key clinical drivers of graft performance.

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

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

    1986-01-01

    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

  4. Adaptive significance of root grafting in trees

    Loehle, C.; Jones, R.

    1988-12-31

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

  5. Autologous patch graft in tube shunt surgery.

    Aslanides, I M; Spaeth, G L; Schmidt, C M; Lanzl, I M; Gandham, S B

    1999-10-01

    To evaluate an alternate method of covering the subconjunctival portion of the tube in aqueous shunt surgery. Evidence of tube erosion, graft-related infection, graft melting, or other associated intraocular complications were evaluated. A retrospective study of 16 patients (17 eyes) who underwent tube shunt surgery at Wills Eye Hospital between July 1991 and October 1996 was conducted. An autologous either "free" or "rotating" scleral lamellar graft was created to cover the subconjunctival portion of the tube shunt. All patients were evaluated for at least 6 months, with a mean follow-up of 14.8 months (range 6-62 months). All eyes tolerated the autologous graft well, with no clinical evidence of tube erosion, or graft-related or intraocular complications. Autologous patch graft in tube shunt surgery appears--in selected cases--to be an effective, safe and inexpensive surgical alternative to allogenic graft materials. It also offers ease of availability, and eliminates the risk of transmitting infectious disease.

  6. Radiation induced graft copolymerization of jute fibre

    Al-Siddique, F.R.; Khan, A.U.; Sheikh, R.A.

    1983-01-01

    Graft copolymerized jute fibres (GCJF) were prepared by γ-ray induced graft copolymerization of various monomers onto bleached and de-waxed jute samples. The effect of γ-ray dose on the tendency of various monomers to form graft co-polymer was studied. It was found that the tendency decreases as follows: methylmethacrylate (MMA)>acrylonitrile (AN)>styrene (STY)>vinylacetate (VA). When the effect of monomer concentration on the formation of graft co-polymer was studied, it was found that a mixture of AN and STY gave a higher amount of grafting than what was observed for STY or AN alone, when used at a comparable concentration. A study on the effect of concentration of methyl alcohol (a swelling agent for jute) on the tendency of the monomers to form graft co-polymer showed that although there is no effect when only AN is used, an appreciable effect is observed if AN is mixed with STY. In the later case the tendency of graft co-polymerization increases with the increase of CH 3 OH concentration. It was further observed that the increase of CH 3 OH also has a positive influence on MMA to form graft co-polymer in the range of 40-90% CH 3 OH. The affinity of GCJF towards moisture has been found to decrease with the increase of polymer loading onto jute. The presence of swelling agents during graft copolymer formation was also found to decrease the affinity of GCJF towards moisture. (author)

  7. Acrylique acid grafted polyolefines. Thermoadhesive applications

    Guimon, Claude

    1979-01-01

    Radiochemical grafting of polyolefines by peroxidation has been industrialized in France for about 10 years by irradiation of these polymers with an electron accelerator and then treated by acrylic acid. Products obtained show a high adhesivity on metallic surfaces above their melting point. The main application of acrylic acid grafted high density polyethylene is composite film with aluminum foil for thermosealing of plastic bottle caps of sterilized milk. Acrylic acid grafted polypropylene is used in suspension in a volatile liquid for aluminum foil coating satisfying food packaging regulations [fr

  8. Grafting heterogeneous catalyst with gamma radiation

    Garnett, J.L.; Long, M.A.; Levot, R.G.

    1984-01-01

    A process for the production of a heterogeneous catalyst comprises the steps of: irradiating an organic macromolecular substrate or a metal substrate with ionising or ultra violet radiation in the presence of a monomer selected from the group consisting of o-, m-, or p- styryl diphenyl phosphine and o-, m- or p- phenyl acrylyl diphenyl phosphine, to graft the monomer to the substrate; and reacting the graft copolymer with a homogeneous catalyst selected from the group consisting of catalytic metal salts and catalytic organometallic complexes such that the graft copolymer conjugate becomes a ligand of the catalyst

  9. Bone Graft Substitutes : Developed for Trauma and Orthopaedic Surgery

    J. van der Stok (Johan)

    2015-01-01

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

  10. Vascularised Fibular Graft for a Radial Defect following Tumour ...

    HP

    The mass was located on the radial aspect of the distal right ... modification, internal or external fixation with bone grafting, structural grafts of ... Our index case report demonstrates that free vascularized fibular graft transfer is a feasible option ... structural support, the potential for graft hypertrophy, relative resistance to ...

  11. Hot callusing for propagation of American beech by grafting

    David W. Carey; Mary E. Mason; Paul Bloese; Jennifer L. Koch

    2013-01-01

    To increase grafting success rate, a hot callus grafting system was designed and implemented as part of a multiagency collaborative project to manage beech bark disease (BBD) through the establishment of regional BBD-resistant grafted seed orchards. Five years of data from over 2000 hot callus graft attempts were analyzed using a logistic regression model to determine...

  12. Bridging Graft in Irreparable Massive Rotator Cuff Tears: Autogenic Biceps Graft versus Allogenic Dermal Patch Graft.

    Rhee, Sung Min; Oh, Joo Han

    2017-12-01

    Few comparative studies have reported on the use of biologic grafts for irreparable massive rotator cuff tears. The purpose of this study was to assess the results of arthroscopic bridging graft in irreparable massive rotator cuff tears using an autogenic long head of biceps tendon (LHBT) or an allogenic dermal patch (ADP). We retrospectively reviewed 24 patients treated using the LHBT (group I) and eight patients with complete rupture of the LHBT treated using an ADP (group II) since 2011. Preoperative Goutallier's fatty degeneration, range of motion (ROM), visual analogue scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES) score, and Quick Disabilities of the Arm, Shoulder, and Hand (DASH) score were assessed and healing failure was evaluated at 1 year after surgery by ultrasonography or magnetic resonance imaging. The mean fatty degeneration in groups I and II was 3.9 and 3.6 for the supraspinatus ( p = 0.288), 2.7 and 2.9 for the infraspinatus ( p = 0.685), 0.9 and 1.3 for the subscapularis ( p = 0.314), and 1.3 and 3.0 for the teres minor ( p = 0.005), respectively. Subscapularis tears were found in 8 patients (33.3%) in group I and in 7 patients (87.5%) in group II ( p = 0.023). Mean ROMs and functional scores improved significantly in group I (forward flexion: 121.7° to 153.3°, p = 0.010; external rotation: 32.7° to 52.7°, p = 0.001; external rotation at 90°: 63.3° to 74.5°, p = 0.031; internal rotation: T10.5 to T9.3, p = 0.045; VAS: 7.0 to 1.1, p rotator cuff tears, especially in patients with severe fatty degeneration in the teres minor or combined biceps and subscapularis tears.

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

    Jung Dug Yang

    2016-09-01

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

  14. Delayed grafting for banked skin graft in lymph node flap transfer.

    Ciudad, Pedro; Date, Shivprasad; Orfaniotis, Georgios; Dower, Rory; Nicoli, Fabio; Maruccia, Michele; Lin, Shu-Ping; Chuang, Chu-Yi; Chuang, Tsan-Yu; Wang, Gou-Jen; Chen, Hung-Chi

    2017-02-01

    Over the last decade, lymph node flap (LNF) transfer has turned out to be an effective method in the management of lymphoedema of extremities. Most of the time, the pockets created for LNF cannot be closed primarily and need to be resurfaced with split thickness skin grafts. Partial graft loss was frequently noted in these cases. The need to prevent graft loss on these iatrogenic wounds made us explore the possibility of attempting delayed skin grafting. We have herein reported our experience with delayed grafting with autologous banked split skin grafts in cases of LNF transfer for lymphoedema of the extremities. Ten patients with International Society of Lymphology stage II-III lymphoedema of upper or lower extremity were included in this study over an 8-month period. All patients were thoroughly evaluated and subjected to lymph node flap transfer. The split skin graft was harvested and banked at the donor site, avoiding immediate resurfacing over the flap. The same was carried out in an aseptic manner as a bedside procedure after confirming flap viability and allowing flap swelling to subside. Patients were followed up to evaluate long-term outcomes. Flap survival was 100%. Successful delayed skin grafting was done between the 4th and 6th post-operative day as a bedside procedure under local anaesthesia. The split thickness skin grafts (STSG) takes more than 97%. One patient needed additional medications during the bedside procedure. All patients had minimal post-operative pain and skin graft requirement. The patients were also reported to be satisfied with the final aesthetic results. There were no complications related to either the skin grafts or donor sites during the entire period of follow-up. Delayed split skin grafting is a reliable method of resurfacing lymph node flaps and has been shown to reduce the possibility of flap complications as well as the operative time and costs. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  15. Preparation of poly(vinylbenzyl chloride)-grafted PFA film by a simultaneous irradiation grafting method

    Fei, Geng; Shin, Jun Hwa; Nho, Young Chang; Lee, Youn Sik

    2009-01-01

    In this study, PFA-g-PVBC films were prepared by a radiation grafting of vinylbenzyl chloride (VBC) monomer onto poly(tetrafluoroethylene-co-perfluoro propyl vinyl ether) (PFA) films by simultaneous irradiation method. IR, TGA, and SEM-EDX instruments were utilized to confirm the successful preparation of the grafted film. The effects of several irradiation conditions, including the dose, VBC concentration, and film thickness on the degree of grafting of PFA-g-PVBC film were investigated

  16. Determination of the distribution of graft yields following a radiation-induced graft copolymerization

    Schipschack, K.; Wagner, H.; Sawtschenko, L.

    1976-01-01

    In the radiation-induced graft copolymerization on solid initial polymers a distribution of graft yields takes place along the cross-sections of samples. Methods for determining this distribution, which are described in the literature, are reviewed. In our own investigations boards made of ethylene-vinyl acetate copolymers and grafted with vinyl chloride were used. Distributions of the grafted component obtained by infrared analysis of microtome cuts parallel to the surface are partly rather inhomogeneous, and are interpreted as dependent on the experimental parameters. (author)

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

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

    2013-01-01

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

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

    Ying Guan

    2016-08-01

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

  19. An Introduction to the Septal Extension Graft

    Myung-Hoon Kim

    2014-01-01

    Full Text Available The septal extension graft is a very useful method of controlling nasal lengthening and tip projection, rotation, and shape by fixing a graft to the septum, which leads to a strong supporting structure. Enhancing graft stability is important for better long-term outcomes and minimizing complications or relapse, and even more efficient application of these methods is needed for East Asians who lack enough cartilage to be harvested in addition to possessing a weak cartilage framework. In this paper, the methods for overcoming the drawbacks of the septal extension graft, such as instability, a fixed tip, and insufficiency of cartilage, are presented, and the applications of each method for greater satisfaction with surgical outcomes are also discussed.

  20. Radiation-induced grafting onto wool

    Muller-Schulte, D.

    1979-10-01

    Radiation-induced grafting tests were done on single wool fibres. Different vinyl monomers were used for this purpose and they were grafted in twenty different solvents which were selected for their swelling effiency and solvent parameters. The tests were done once with and once without the addition of water. The presence of water causes the polymer uptake to increase considerably. Formic acid/methanol and methanol were found to be the most suitable solvent systems, as they have the highest hydrogen-bond interaction effiency. The moisture uptake of wool depends on the hydrophily and hydrophoby of the grafted polymers. The single-fibre tests serve as a basis for analogous grafting tests on wool fabrics. The permanent- press was improved by graftng with hydrophoric polymers and polymers with a high glass-transition temperature [af

  1. Pinch grafting for chronic venous leg ulcers in general practice

    Steele, Keith

    1985-01-01

    Twenty-five patients with chronic venous leg ulcers were treated in general practice by pinch grafting. Fifteen of the ulcers (60%) were completely healed one year after grafting. Prior to grafting 19 patients (76%) complained of daily pain in the ulcer. These patients experienced complete relief from pain after grafting. Pinch grafting is a simple, safe and effective therapy when applied in a domiciliary environment.

  2. Strategies to improve macroencapsulated islet graft survival

    Sörenby, Anne

    2007-01-01

    Chronic immunosuppressive therapy may have severe side-effects. In cell transplantation, the graft can be encapsulated within a membrane chamber, providing a physical barrier against the immune system. The cell graft then becomes dependent on the diffusion of nutrients and oxygen from the surrounding microcirculation. A major drawback has been the formation of avascular fibrotic tissue around the chamber. The immunoprotective device studied (TheraCyte ) has an outer membrane...

  3. Local graft irradiation in renal transplant rejection

    Kawamura, Masashi; Kataoka, Masaaki; Itoh, Hisao

    1990-01-01

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

  4. Graft-copolymerization onto carbon black

    Nakase, Yoshiaki; Nishii, Masanobu; Kijima, Toshiyuki; Kato, Hiroshi.

    1988-07-01

    Radiation-induced graft copolymerization of vinyl monomer onto carbon black was performed. During the γ-ray- and electron beam-induced polymerization (In-source), or the electron beam post-polymerization, the graft-copolymerization behavior was affected by the kinds of both carbon blacks and monomers, i.e. the smaller the size of carbon black particles, the higher the apparent grafted fraction. Homopolymer in the grafted carbon black samples was washed out by the solvent of the polymer, and the extracted polymer seemed to be dimer or trimer of the used monomer. In the case of the post-polymerization with the pre-irradiation doses of 50 Mrad, homopolymer was hardly observed. The polymer sheets of plastics or rubbers with grafted carbon black had an electrical conductivity unalterable considerably by the heating cycles. The particles of grafted carbon black in the sheet might be kept much more at the surface layer within 100 nm depth than at the inner layer. (author)

  5. Photoacoustic detection of neovascularities in skin graft

    Yamazaki, Mutsuo; Sato, Shunichi; Saitoh, Daizo; Ishihara, Miya; Okada, Yoshiaki; Ashida, Hiroshi; Obara, Minoru

    2005-04-01

    We previously proposed a new method for monitoring adhesion of skin graft by measuring photoacoustic (PA) signal originated from the neovascularities. In this study, immunohistochemical staining (IHC) with CD31 antibody was performed for grafted skin tissue to observe neovascularity, and the results were compared with PA signals. We also used a laser Doppler imaging (LDI) to observe blood flow in the grafted skin, and sensitivity of PA measurement and that of LDI were compared. In rat autograft models, PA signals were measured for the grafted skin at postgrafting times of 0-48 h. At 6 h postgrafting, PA signal was observed in the skin depth region of 500-600 mm, while the results of IHC showed that angiogenesis occurred at the depth of about 600 mm. Depths at which PA signal and angiogenesis were observed decreased with postgrafting time. These indicate that the PA signal observed at 6 h postgrafting originated from the neovascularities in the skin graft. Results of LDI showed no blood-originated signal before 48 h postgrafting. These findings suggest that PA measurement is effective in monitoring the adhesion of skin graft in early stage after transplantation.

  6. Additive effects in radiation grafting and curing

    Viengkhou, V.; Ng, L.

    1996-01-01

    Full text: Detailed studies on the accelerative effect of novel additives in radiation grafting and curing using acrylated monomer/oligomer systems have been performed in the presence of ionising radiation and UV as sources. Methyl methacrylate (MMA) is used as typical monomer for these grafting studies in the presence of the additives with model backbone polymers, cellulose and propropylene. Additives which have been found to accelerate these grafting processes are: mineral acid, occlusion compounds like urea, thermal initiators and photoinitiators as well as multifunctional monomers such as multifunctional acrylates. The results from irradiation with gamma rays have also been compared with irradiation from a 90W UV lamp. The role of the above additives in accelerating the analogous process of radiation curing has been investigated. Acrylated urethanes, epoxies and polyesters are used as oligomers together with acrylated monomers in this work with uv lamps of 300 watts/inch as radiation source. In the UV curing process bonding between film and substrate is usually due to physical forces. In the present work the presence of additives are shown to influence the occurrence of concurrent grafting during cure thus affecting the nature of the bonding of the cured film. The conditions under which concurrent grafting with UV can occur will be examined. A mechanism for accelerative effect of these additives in both grafting and curing processes has been proposed involving radiation effects and partitioning phenomena

  7. Isotopic scintigraphy in kidney grafting

    Renfro, Richard.

    1976-01-01

    Isotopic explorations of kidney transplants were performed on sixty-six patients. Three scintigraphic techniques were used: labelled ferrous ascorbate scintigraphy, sequential 99m technetium DTPA scintigraphy and the 131 I hippuran nephrogram. The aim of this study is to analyse the results obtained under different pathological circumstances affecting the transplant, to discuss the advantages of the techniques and to propose a working procedure. The most reliable and accurate technique is the 131 I hippuran nephrogram combined with sequential 99mTc DTPA, by which renal vascularisation may be judged labelled ferrous ascorbate on the other hand is too insensitive. Although the information supplied is mostly contained in the scintigraphic images, the nephrographic curves and the blood radioactivity decay time and rad V/rad R ratio measurements are very helpful in the early diagnosis and differential diagnosis of complications affecting the transplant. The proper use of isotopic scintigraphy in kidney grafting should provide optimum conditions for better survival of the transplant at minimum risk to the patient [fr

  8. Role of graft oversizing in the fixation strength of barbed endovascular grafts.

    Kratzberg, Jarin A; Golzarian, Jafar; Raghavan, Madhavan L

    2009-06-01

    The role of endovascular graft oversizing on risk of distal graft migration following endovascular aneurysm repair for abdominal aortic aneurysm is poorly understood. A controlled in vitro investigation of the role of oversizing in graft-aorta attachment strength for endovascular grafts (EVGs) with barbs was performed. Barbed stent grafts (N = 20) with controlled graft oversizing varying from 4-45% were fabricated while maintaining other design variables unchanged. A flow loop with physiological flow characteristics and a biosynthetic aortic aneurysm phantom (synthetic aneurysm model with a bovine aortic neck) were developed. The stent grafts were deployed into the aortic neck of the bio-synthetic aortic aneurysm phantom under realistic flow conditions. Computed tomography imaging of the graft-aorta complex was used to document attachment characteristics such as graft apposition, number of barbs penetrated, and penetration depth and angle. The strength of graft attachment to the aortic neck was assessed using mechanical pullout testing. Stent grafts were categorized into four groups based on oversizing: 4-10%; 11-20%; 21-30%; and greater than 30% oversizing. Pullout force, a measure of post-deployment fixation strength was not different between 4-10% (6.23 +/- 1.90 N), 11-20% (6.25 +/- 1.84 N) and 20-30% (5.85 +/- 1.89 N) groups, but significantly lower for the group with greater than 30% oversizing (3.67 +/- 1.41 N). Increasing oversizing caused a proportional decrease in the number of barbs penetrating the aortic wall (correlation = -0.83). Of the 14 barbs available in the stent graft, 89% of the barbs (12.5 of 14 on average) penetrated the aortic wall in the 4-10% oversizing group while only 38% (5.25 of 14) did for the greater than 30% group (P barb penetration were found to be positively correlated to pullout force. Greater than 30% graft oversizing affects both barb penetration and graft apposition adversely resulting in a low pullout force in this in vitro

  9. Depth of the graft bed influences split-skin graft contraction.

    Mensik, I.; Lamme, E.N.; Brychta, P.

    2003-01-01

    Contraction of a split-thickness skin graft used for coverage of large defects remains a great problem in plastic, burn and reconstructive surgery. In this study we evaluated healing of split-thickness skin grafts transplanted in wounds on the subcutaneous fat and muscle fascia in pigs. Four young

  10. Physical properties of agave cellulose graft polymethyl methacrylate

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

    2013-11-27

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  11. Study on grafting glycidyl methacrylate onto HDPE membranes by pre-irradiation graft copolymerization

    Tong Long; Zu Jianhua; Liu Xinwen; Sun Guisheng; Yu Chunhui

    2006-01-01

    Glycidyl methacrylate (GMA) was grafted onto HDPE membranes by pre-irradiation method with 1.8 MeV E-beam and a kind of membranes having reactive epoxy groups was successfully synthesized. Effects of monomer concentration, reaction temperature and time and irradiation dose on the grafting yield were studied. Composition, thermo-property and surface morphology of the grafted membranes were studied by FTIR, DSC and Tapping-mode AFM, respectively. The FTIR measurements proved the synthesized copolymer is HDPE-g-GMA. The DSC results indicated the grafted HDPE's melting temperature (T m ) and heat of fusion (ΔH f ( HDPE) ) which was reduced with increasing grafting yield. The AFM images indicated that surface of the HDPE-g-GMA membranes was rougher than the virgin HDPE. (authors)

  12. Development of Highly Efficient Grafting Technique and Synthesis of Natural Polymer-Based Graft Adsorbent

    Ueki, Y; Seko, N; Tamada, M [Japan Atomic Energy Agency, Quantum Beam Science Directorate, Takasaki (Japan)

    2012-09-15

    In the framework of the CRP, Japan has focused on the development of fibrous adsorbents for removal of toxic metal ions and recovery of significant metal ions from industrial wastewater and streaming water. Graft polymerization was carried out by using gamma irradiation facility and electron beam accelerator. Emulsion grafting is a novel topic for synthesis of metal ion adsorbents which are prepared from fibrous trunk polymers such as polyethylene fibre and biodegradable nonwoven fabrics. The emulsion grafting, where monomer micelles are dispersed in water in the presence of surfactant, is a highly efficient and economic grafting technique as compared to general organic solvent system. The resultant cotton-based adsorbent has high adsorption efficiency and high adsorption capacity for Hg, besides, it is biodegradable. Polylactic acid can also be used as a trunk material for the grafting. (author)

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

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

    2015-01-01

    BACKGROUND: Harvesting techniques can affect cellular parameters of autogenous bone grafts in vitro. Whether these differences translate to in vivo bone formation, however, remains unknown. OBJECTIVE: The purpose of this study was to assess the impact of different harvesting techniques on bone fo......: Transplantation of autogenous bone particles harvested with four techniques in the present model resulted in moderate differences in terms of bone formation and graft resorption.......BACKGROUND: Harvesting techniques can affect cellular parameters of autogenous bone grafts in vitro. Whether these differences translate to in vivo bone formation, however, remains unknown. OBJECTIVE: The purpose of this study was to assess the impact of different harvesting techniques on bone...... formation and graft resorption in vivo. MATERIAL AND METHODS: Four harvesting techniques were used: (i) corticocancellous blocks particulated by a bone mill; (ii) bone scraper; (iii) piezosurgery; and (iv) bone slurry collected from a filter device upon drilling. The grafts were placed into bone defects...

  14. Adolescent External Iliac Artery Trauma: Recurrent Aneurysmal Dilatation of an Iliofemoral Saphenous Vein Graft Treated by Stent-Grafting

    Lenton, James; Davies, John; Homer-Vanniasinkam, S.; McPherson, Simon

    2008-01-01

    An adolescent male sustained a severe penetrating injury to the external iliac artery. Emergency surgical revascularization was with a reversed long saphenous vein interposition graft. The primary graft and the subsequent revision graft both became aneurysmal. The second graft aneurysm was successfully excluded by endovascular stent-grafts with medium-term primary patency. A venous graft was used initially rather than a synthetic graft to reduce the risk of infection and the potential problems from future growth. Aneurysmal dilatation of venous grafts in children and adolescents is a rare but recognized complication. To the best of our knowledge, exclusion of these aneurysms with stent-grafts has not been previously reported in the adolescent population.

  15. Corneal graft reversal: Histopathologic report of two cases.

    Qahtani, Abdullah A; Alkatan, Hind M

    2014-10-01

    Graft reversal is a rare cause for failed PKP. In this case report we are presenting 2 graft failure cases in which the corneal grafts were reversed unintentionally. The onset of signs of graft failure, however was variable. We have included their clinical course and the histopathologic findings of the removed corneal grafts. A total of 6 cases including ours have been reported so far. The aim of this report is to attract the attention of corneal surgeons to an additional rare cause for failed penetrating keratoplasty (PKP) which is donor graft reversal.

  16. Grafting of acrylamide onto synthetic co polyamide by gamma irradiation

    Hamoud, M R; Qamhieyh, E A [Chemistry Dept., College of Ibn Al-Haitham Baghdad university-Adhamiyah-Baghdad- (Iraq)

    1995-10-01

    Grafted copolymer was prepared by using gamma irradiation to graft acrylamide onto polymeric molecule prepared by interfacial condensation between two diamine molecules like 1,2 diamino propane and 1,6 diamino-hexane in aqueous layer with sebacoyl chloride in organic layer. The resulted co polyamide was grafted with acrylamide using gamma irradiation. The optimum conditions of grafting reaction were found, also various factors such as the effect of solvents, redox systems and the role water on the radiochemical grafting were studied. Many techniques were used in the characterization of the copolymer before and after grafting. 8 figs.,.

  17. Characterization and Some Properties of Functionalized Graft Copolymer

    Hegazy El-Sayed, A.; Kamal, H.; Mahmoud, Gh.A.; Khalifa, N.A.

    2000-01-01

    The study involved the investigation and characterization of membranes prepared by graft copolymerization of acrylonitrile (AN) and vinyl acetate (VAc) binary monomers onto low density polyethylene (LDPE) and isotactic polypropylene (IPP). The mutual gamma-irradiation method was used as a grafting technique. The effects of grafting and chemical treatments on the thermal properties and crystallinity of prepared graft copolymer have been investigated using DSC, TGA and XRD. IR spectra recorded before and after grafting and also for the chemically treated membranes to elucidate the structural changes occurred due to grafting and chemical treatments

  18. Corneal Graft Rejection: Incidence and Risk Factors

    Alireza Baradaran-Rafii

    2008-12-01

    Full Text Available

    PURPOSE: To determine the incidence and risk factors of late corneal graft rejection after penetrating keratoplasty (PKP. METHODS: Records of all patients who had undergone PKP from 2002 to 2004 without immunosuppressive therapy other than systemic steroids and with at least one year of follow up were reviewed. The role of possible risk factors such as demographic factors, other host factors, donor factors, indications for PKP as well as type of rejection were evaluated. RESULTS: During the study period, 295 PKPs were performed on 286 patients (176 male, 110 female. Mean age at the time of keratoplasty was 38±20 (range, 40 days to 90 years and mean follow up period was 20±10 (range 12-43 months. Graft rejection occurred in 94 eyes (31.8% at an average of 7.3±6 months (range, 20 days to 39 months after PKP. The most common type of rejection was endothelial (20.7%. Corneal vascularization, regrafting, anterior synechiae, irritating sutures, active inflammation, additional anterior segment procedures, history of trauma, uncontrolled glaucoma, prior graft rejection, recurrence of herpetic infection and eccentric grafting increased the rate of rejection. Patient age, donor size and bilateral transplantation had no significant influence on graft rejection. CONCLUSION: Significant risk factors for corneal graft rejection include

  19. Prediction of coronary artery bypass graft flow

    Tamiya, Eiji; Hada, Yoshiyuki; Asano, Ken-ichi; Iio, Masahiro.

    1991-01-01

    To predict the coronary artery bypass graft (CABG) flow based on the time density curve (TDC) obtained from the digital subtraction aortograms (DSA), we developed a pulsatile CABG model (perfusion pressure 60,130 mmHg, pulse rate 53,126/min, cardiac output 3-7 l/min, diameter of the graft 2.1∼6.0 mm). After positioning the regions of interest (ROI), we injected contrast medium(5∼40 ml/sec, 5∼40 ml) into the outlet conduit. Concerning the TDCs, we calculated appearance time (Ta), peak densities (Dp), peak time (Tp), disappearance time (Td), integral of TDC, ΔTp (difference of Tp between two ROI) and ΔTa (difference of Ta between two ROI). Perfusion pressure, graft flow and output curve were similar to those of patients with CABG. Ta, Tp, Td, and ΔTp were affected by both the injection rate and the volume of the contrast medium; while Dp and the TDC integral were only affected by the latter parameter. Under the same conditions of contrast medium injection, the TDC depended strongly on graft flow, diameter of the graft, output and pulse rate. 21.6+0.92π·d 2 /4·Δ1/ΔTp·60 provided the most accurate estimation of CABG flow (r=0.865, p<0.01). We conclude that densitometric analysis of DSA may be useful in the prediction of CABG flow. (author)

  20. Long-term results of PTFE grafts.

    Hedin, Ulf

    2015-01-01

    Vascular surgeons are essential in "lifeline" creation for hemodialysis patients and should be the central player in any multidisciplinary access service together with nephrologists, dialysis staff and interventional radiology. In this position, access surgeons are involved in complicated clinical decision making regarding primary and secondary access selection, which throughout the last decade has been largely aided, and influenced, by national and international guidelines as well as other initiatives. These recommendations, unanimously and appropriately, advocate the placement of native fistulas over synthetic grafts (the majority grafts from expanded polytetrafluoroethylene, ePTFE, herein referred to as PTFE) based on the superiority of fistulas with respect to complications such as infections and thrombosis. Nevertheless, the use of PTFE grafts for hemodialysis access is an accepted and firmly established alternative to native fistulas where data today reveal unwanted consequences to overinterpretation of established guidelines such as increased catheter use. This information highlights a need for an adjustment of access selection strategies based on patient-centered algorithms. Here, available results on PTFE graft performance in hemodialysis access is recapitulated, with respect to both conventional grafts and technical modifications, and conclude with a modified approach to primary access selection.

  1. Frenuloplasty with a splitthicknes skin graft

    Mohammadi, G.; Nnaderpour, M.

    2006-01-01

    The purpose of this study was to investigate the severity of presenting symptomatology in patients with ankyloglossia and to assess the surgical results of patients undergoing frenuloplasty with split thickness skin graft. During a 4 year period from September 1998 through September 2002, 19 patients of ankyloglosia underwent frenuloplasty with a split thickness skin graft. All skin grafts were taken from arm. There were 11 males and 8 females. The average length of the lingual frenulum was 3.5 mm. Twelve children were over 4 years old and were primarily operated with this technique. In the 7 patients, Z plasty had been performed previously but failed and cicatrisation caused ankyloglosia. There were two minor postoperative complications, one hematoma, and other graft dehiscence with cicatrisation. The mobility of the tongue after one year was excellent. There were no complications in donor site. Frenuloplasty with split thickness skin graft is the best and easy procedure with good results for children over 4 years and those who fail primary closure. (author)

  2. Radiographic analysis of pasteurized autologous bone graft

    Ahmed, Adel Refaat; Manabe, Jun; Kawaguchi, Noriyoshi; Matsumoto, Seiichi; Matsushita, Yasushi

    2003-01-01

    Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors. (orig.)

  3. Aortic reconstruction with bovine pericardial grafts

    Silveira Lindemberg Mota

    2003-01-01

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

  4. Radiographic analysis of pasteurized autologous bone graft

    Ahmed, Adel Refaat [Department of Orthopedic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Kamiikebukuro 1-37-1, Toshima-ku, 170-0012, Tokyo (Japan); Department of Orthopedic Surgery, Alexandria University, Alexandria (Egypt); Manabe, Jun; Kawaguchi, Noriyoshi; Matsumoto, Seiichi; Matsushita, Yasushi [Department of Orthopedic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Kamiikebukuro 1-37-1, Toshima-ku, 170-0012, Tokyo (Japan)

    2003-08-01

    Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors. (orig.)

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

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

    2017-03-01

    Penile inversion vaginoplasty is considered to be the gold standard for gender reassignment surgery in transgender women. The use of additional full-thickness skin graft as neovaginal lining is controversial. Some believe that having extra penile skin for the vulva gives better aesthetic results. Others believe that it gives inferior functional results because of insensitivity and skin graft contraction. Transgender women undergoing penile inversion vaginoplasty were studied prospectively. The option to add full-thickness skin graft is offered in patients where the penile skin length lies between 7 and 12 cm. Neovaginal depth was measured at surgery and during follow-up (3, 13, 26, and 52 weeks postoperatively). Satisfaction with the aesthetic result, neovaginal depth, and dilation regimen during follow-up were recorded. Satisfaction, sexual function, and genital self-image were assessed using questionnaires. A total of 100 patients were included (32 with and 68 without additional full-thickness skin graft). Patient-reported aesthetic outcome, overall satisfaction with the neovagina, sexual function, and genital self-image were not significantly associated with surgical technique. The mean intraoperative neovaginal depth was 13.8 ± 1.4 cm. After 1 year, this was 11.5 ± 2.5 cm. The largest decline (-15 percent) in depth is observed in the first 3 postoperative weeks (p skin graft use, in penile inversion vaginoplasty. The additional use of full-thickness skin graft does not influence neovaginal shrinkage, nor does it affect the patient- and physician-reported aesthetic or functional outcome. Therapeutic, IV.

  6. A COMPARATIVE STUDY OF TYMPANOPLASTY USING SLICED CARTILAGE GRAFT VS. TEMPORALIS FASCIA GRAFT

    Rahul Ashok Telang

    2018-02-01

    Full Text Available BACKGROUND The objective of the study was to compare the hearing improvement after using sliced cartilage graft with that of temporalis fascia and to compare the graft take-up between the two graft materials. MATERIALS AND METHODS A prospective clinical study including 60 patients with chronic mucosal otitis media, who were selected randomly from the outpatient department, after obtaining their consent were divided into 2 groups of 30 each, and evaluated according the study protocol. Their pre-operative audiometry was recorded and both groups of patients underwent surgery with one of the graft materials- temporalis fascia or sliced tragal cartilage with a thickness of 0.5 mm. All patients were regularly followed up and post-operative audiometry was done at 3 months. The hearing improvement in the form of closure of air-bone-gap and graft take-up was analysed statistically. RESULTS The temporalis fascia graft group had a pre-operative ABG of 22.33 ± 6.24 dB and post-operative ABG of 12.33 ± 4.72 dB with hearing improvement of 10.00 dB. The sliced cartilage graft group had a pre-operative ABG of 20.77 ± 5.75 dB and postoperative ABG of 10.50 ± 4.46 dB with hearing improvement of 10.27 dB. In the temporalis fascia group, 28 (93.3% patients had good graft take-up and in the sliced cartilage group 29 (96.7% had good graft take-up. There was statistically significant hearing improvement in both of our study groups but there was no statistically significant difference between the two groups. There was no statistically significant difference in graft take-up also. CONCLUSION Sliced cartilage graft is a good auto-graft material in tympanoplasty, which can give good hearing improvement and has good graft take-up, which is comparable with that of temporalis fascia.

  7. Over-the-top ACL Reconstruction Plus Extra-articular Lateral Tenodesis With Hamstring Tendon Grafts: Prospective Evaluation With 20-Year Minimum Follow-up.

    Zaffagnini, Stefano; Marcheggiani Muccioli, Giulio Maria; Grassi, Alberto; Roberti di Sarsina, Tommaso; Raggi, Federico; Signorelli, Cecilia; Urrizola, Francisco; Spinnato, Paolo; Rimondi, Eugenio; Marcacci, Maurilio

    2017-12-01

    There are few published studies with very long-term follow-up of combined intra- and extra-articular anterior cruciate ligament (ACL) reconstruction. To analyze clinical and radiographic outcomes of over-the-top ACL reconstruction plus extra-articular lateral tenodesis with autologous hamstrings at minimum 20-year follow-up. Case series; Level of evidence, 4. Of 60 originally eligible patients who underwent over-the-top ACL reconstruction with double-stranded hamstring tendon (leaving intact graft tibial insertions) and extra-articular lateral plasty (performed with the remnant part of tendons), 52 were prospectively evaluated at a minimum 20-year follow-up (mean follow-up, 24 years; 41 men, 11 women; mean age at time of surgery, 25.5 ± 7.6 years). Twenty-nine patients were available for prospective evaluations: clinical (Lysholm, Tegner, and objective International Knee Documentation Committee [IKDC]), instrumented (KT-2000), and radiographic (standard, long-standing, and Merchant views). Subjective KOOS (Knee injury and Osteoarthritis Outcome Score) and objective inertial sensor pivot-shift analysis (KiRA) were carried out at final follow-up. Twenty-three patients were investigated by phone interview for subjective Tegner score and documented complications, rerupture, or revision surgery. At final follow-up, mean Lysholm score was 85.7 ± 14.6; median Tegner score, 4 (range, 3-5); sport activity resumption, 86.2%; and objective IKDC score, good or excellent in 86% of patients (31%, A; 55%, B). Only 3 of 26 patients (12%) had >5-mm manual maximum KT-2000 side-to-side difference. KiRA system documented positive pivot-shift (>0.9-m/s 2 tibial acceleration side-to-side difference) in these 3 of 26 patients (12%). Statistically significant changes were as follows: decrease in Tegner score from 7 (range, 6-8) at 5-year follow-up to 4 (range, 3-5) at 10 years ( P < .0001) and decrease in Lysholm score from 96.1 ± 7.3 at 10-year follow-up to 85.7 ± 14.6 at 20 years

  8. [Localized purpura revealing vascular prosthetic graft infection].

    Boureau, A S; Lescalie, F; Cassagnau, E; Clairand, R; Connault, J

    2013-07-01

    Prosthetic graft infection after vascular reconstruction is a rare but serious complication. We report a case of infection occurring late after implantation of an iliofemoral prosthetic vascular graft. The Staphylococcus aureus infection was revealed by vascular purpura localized on the right leg 7 years after implantation of a vascular prosthesis. This case illustrates an uncommonly late clinical manifestation presenting as an acute infection 7 years after the primary operation. In this situation, the presentation differs from early infection, which generally occurs within the first four postoperative months. Diagnosis and treatment remain a difficult challenge because prosthetic graft infection is a potentially life-threatening complication. Morbidity and mortality rates are high. Here we detail specific aspects of the clinical and radiological presentation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Meshed split skin graft for extensive vitiligo

    Srinivas C

    2004-05-01

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

  10. [Vascular trombosis of renal graft: 9 cases].

    Kaaroud, Hayet; Béji, Soumaya; Ben Hamida, Fethi; Rais, Lamia; Ben Abdallah, Taieb; El Younsi, Fethi; Ben Moussa, Fatma; Abderrahim, Ezzedine; Bardi, Rafika; Ayed, Khaled; Chebil, Mohamed; Kheder, Adel

    2008-04-01

    Allograft renal thrombosis can occur in 1 to 6% of cases. Many predisposing factors has been identified especially alteration of coagulation. We analyzed in this study frequency and predisposing factors of renal graft thrombosis. We report a retrospective study including 319 renal transplant recipients. Nine patients (2.8%) presented veinous graft thrombosis in 5 cases and arterial thombosis in 4 cases. There were 6 men and 3 women aged of 30.6 years meanly (10-56) which developed the thrombosis 6 days (1-48) after the transplantation. All patients were detransplanted after 16.2 days and 1 patient died. Thrombosis constitute an important cause of graft loss. A perfect surgical technic and prophylactic treatment in high risk patients are necessary to reduce this complication.

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

    Donald, P.J.

    1986-01-01

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

  12. Primary nerve grafting: A study of revascularization.

    Chalfoun, Charbel; Scholz, Thomas; Cole, Matthew D; Steward, Earl; Vanderkam, Victoria; Evans, Gregory R D

    2003-01-01

    It was the purpose of this study to evaluate the revascularization of primary nerve repair and grafts using orthogonal polarization spectral (OPS) (Cytometrix, Inc.) imaging, a novel method for real-time evaluation of microcirculatory blood flow. Twenty male Sprague Dawley rats (250 g) were anesthetized with vaporized halothane and surgically prepared for common peroneal nerve resection. Group I animals (n = 10) underwent primary neurorraphy following transection, utilizing a microsurgical technique with 10-0 nylon suture. Group II (n = 10) animals had a 7-mm segment of nerve excised, reversed, and subsequently replaced as a nerve graft under similar techniques. All animals were evaluated using the OPS imaging system on three portions (proximal, transection site/graft, and distal) of the nerve following repair or grafting. Reevaluation of 5 animals randomly selected from each group using the OPS imaging system was again performed on days 14 and 28 following microsurgical repair/grafting. Values were determined by percent change in vascularity of the common peroneal nerve at 0 hr following surgery. Real-time evaluation of blood flow was utilized as an additional objective criterion. Percent vascularity in group I and II animals increased from baseline in all segments at day 14. By day 28, vascularity in nerves of group I rats decreased in all segments to values below baseline, with the exception of the transection site, which remained at a higher value than obtained directly after surgical repair. In group II animals, vascularity remained above baseline in all segments except the distal segment, which returned to vascularity levels similar to those at 0 hr. Further, occlusion of the vessels demonstrated in the graft and distal segments following initial transection appeared to be corrected. This study suggests that revascularization may occur via bidirectional inosculation with favored proximal vascular growth advancement. The use of real-time imaging offers a

  13. Infolding of fenestrated endovascular stent graft.

    Zelt, Jason G E; Jetty, Prasad; Hadziomerovic, Adnan; Nagpal, Sudhir

    2017-09-01

    We report a case of infolding of a fenestrated stent graft involving the visceral vessel segment after a juxtarenal abdominal aorta aneurysm repair. The patient remains free of any significant endoleak, and the aortic sac has shown regression. The patient remains asymptomatic, with no abdominal pain, with normal renal function, and without ischemic limb complications. We hypothesize that significant graft oversizing (20%-30%) with asymmetric engineering of the diameter-reducing ties may have contributed to the infolding. Because of the patient's asymptomatic nature and general medical comorbidities, further intervention was deemed inappropriate as the aneurysmal sac is regressing despite the infolding.

  14. Expanded polytetrafluoroethylene graft fistula for chronic hemodialysis.

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

    1979-01-01

    In a retrospective study of 66 PTFE arteriovenous fistulae and 71 BCH arteriovenous fistulae for dialysis access, PTFE had a higher patency rate than BCH at 12 months (62.4 versus 32.5%). PTFE was easier to work with and easier to handle in the face of infection. The lateral upper arm approach to placement of the PTFE graft is desirable in patients who have had multiple previous access procedures because this area is usually free from scarring, is distant from neurovascular structures, and provides a greater length of graft for needle punctures.

  15. Graft copolimerization of hydrophilic monomers onto irradiated polypropylene fibers

    Sundardi, F.

    1978-01-01

    A method of graft copolymerization of hydrophilic monomers, such as 1-vinyl-2-pyrrolidone, acrylonitrile, acrylic acid, and acrylamide, onto irradiated polypropylene fibers has been studied. γ ray as well as electron beam were employed for the irradiation processes. Graft-copolymerization kinetics and the properties of grafted fibers have been investigated. Moisture regain, dyes absorption, and melting point of the grafted fibers were found to increase with the increasing of the degree of grafting. Polypropylene for 1-vinyl-2-pyrrolidone grafted fibers showed excellent dye absorption for almost all kinds of dyes such as direct, basic, acid, reactive, disper, and naphthol dyes. However, for polypropylene acrylic acid grafted fibers, the colorfastness to washing was found to be unsatisfactory. The colorfastness to washing for polypropylene 1-vinyl-2-pyrrolidone grafted fibers was found to be fairly good for certain types of dyes such as vat and naphthol dyes. (author)

  16. Current Role of Imaging in Diagnosing Aortic Graft Infections

    Bruggink, Janneke L. M.; Slart, Riemer H. J. A.; Pol, Jillis A.; Reijnen, Michel M. P. J.; Zeebregts, Clark J.

    2011-01-01

    Vascular prosthetic graft infection is a rare but serious complication after aortic graft replacement, with high morbidity and mortality rates. Therefore, adequate diagnostics are needed to detect and treat these infections as early as possible. Several imaging modalities provide different

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

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

    2001-01-01

    Revascularisation of bone grafts is influenced by both the anatomical origin and the pre-implantation processing of the graft. We investigated the revascularisation by entrapment of 141Ce (cerium)-labelled microspheres in large, fresh and demineralised syngeneic grafts of predominantly cancellous...... (iliac bone) or cortical (tibial diaphysis) bone three weeks after heterotopic implantation in rats. The mean (SD) 141Ce deposition index (counts per minute (cpm) of mg recovered implant/cpm of mg host iliac bone) was higher in fresh iliac bone grafts, 0.98 (0.46) compared to that of demineralised iliac...... bone, 0.32 (0.20), p bone grafts, 0.51 (0.27), p = 0.007. We found no significant difference in the mean 141Ce deposition index between fresh tibial bone grafts and demineralised tibial bone grafts, 0.35 (0.42), p = 0.4, or between demineralised tibial grafts and demineralised...

  18. Lycopene and flesh colour differences in grafted and non-grafted watermelon

    Fekete D.; Stéger-Máté M.; Bőhm V.; Balázs G.; Kappel N.

    2015-01-01

    The experiment was carried out in three regions in Hungary (Jászszentandrás, Cece, Újkígyós) in 2013 to determine the fruit quality of grafted watermelon (Citrullus lanatus Thunb.). The “RX 467” seedless watermelon variety was grafted on two commercial rootstocks “FR STRONG” [Lagenaria siceraria (Mol.) Standl.] and “RS 841” (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne). The lycopene and flesh colours are important quality characteristics even of the selfrooted and grafted watermel...

  19. Sulfonated hydrocarbon graft architectures for cation exchange membranes

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

    2013-01-01

    A synthetic strategy to hydrocarbon graft architectures prepared from a commercial polysulfone and aimed as ion exchange membrane material is proposed. Polystyrene is grafted from a polysulfone macroinitiator by atom transfer radical polymerization, and subsequently sulfonated with acetyl sulfate...... to various degrees. Series of grafting densities and graft lengths are prepared, and membranes are solvent cast from DMSO. The membrane properties in aqueous environments are evaluated from their water swelling behavior, and their thermal properties and stability are investigated by thermogravimetric...

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

    Guzman, R; Meyer, M; Lövblad, K O

    1999-01-01

    Survival and integration into the host brain of grafted tissue are crucial factors in neurotransplantation approaches. The present study explored the feasibility of using a clinical MR scanner to study striatal graft development in a rat model of Huntington's disease. Rat fetal lateral ganglionic...... time-points graft location could not be further verified. Measures for graft size and ventricle size obtained from MR images highly correlated with measures obtained from histologically processed sections (R = 0.8, P fetal rat lateral ganglionic...

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

    Klasen, Hendrik Jan

    1981-01-01

    In the course of more than a hundred years, skin grafting has become a standard procedure in surgery. The indications for the several types of grafting have become rather uniform.The technical aids at the operations only differ in details. Especially the vast experience gained in World War II provided the opportunity to develop the technique of skin grafting and so the evolution of present day plastics surgery. However, virtually every step in the field of indications, selection of grafts, te...

  2. Radiation grafting of dimethylaminopropylacrylamide and dimethylaminopropylmethacrylamide onto polyethylene

    Burillo, Guillermina; Oseguera, M.A. [UNAM, Inst. de Ciencias Nucleares, Mexico City (Mexico); Vazquez, Carmen; Castillo, L.P. del [UNAM, Inst. de Investigaciones en Materiales, Mexico City (Mexico)

    1997-11-01

    Radiation-induced grafting of dimethylaminopropylacrylamide and dimethylamino-propylmethacrylamide onto polyethylene films, by direct grafting of the vinyl monomers to a polymer by mutual irradiation, has been investigated. The kinetics of the reaction were studied at different irradiation temperatures, monomer concentration and dose rates of gamma rays, and the appropriate reaction conditions for graft polymerization were determined. The thermal and mechanical behavior of the grafted films by means of DMA, TMA, DSC and TGA were also investigated. (author).

  3. Radiation-induced grafting from binary mixture of monomers onto cellulose acetate film and the characterization of the graft copolymer

    Bhattacharyya, S.N.; Maldas, D.

    1984-01-01

    Binary mixtures of styrene and acrylamide in methanol-water were grafted onto cellulose acetate films by taking recourse to preirradiation grafting technique. The extent of total grafting was determined from the measured weight increase. The percent acrylamide residue in the graft copolymer was calculated from the observed nitrogen content but the polystyrene residue in the grafted sample was determined by IR spectral studies. When the specific permeability of water vapour through the grafted films is measured, it is observed that the specific permeability increases with the increase of grafting of acrylamide in all humidities, but in case of styrene which is a nonpolar molecule the permeability is found to show a reversed order. In the case of mixed graft the permeability pattern pertains to that when both styrene and acrylamide have their effective roles to play. (author)

  4. Immobilization of urease on grafted starch by radiation method

    Nguyenanh Dung; Nguyendinh Huyen

    1995-01-01

    The acrylamide was grafted by radiation onto starch which is a kind of polymeric biomaterial. The urease was immobilized on the grafted starch. Some experiments to observe the quantitative relationships between the percent graft and the activity of immobilized enzyme were determined. The enzyme activity was maintained by more than seven batch enzyme reactions. (author)

  5. Anterior palatal island advancement flap for bone graft coverage ...

    ... Palatal Island Advancement Flap was effective in bone graft coverage in premaxillary edentulous area. Conclusion: It can be used as an aid for bone graft coverage of premaxillary edentulous ridge, where the need for mucosa is small in width but long in length. Keywords: Anterior maxilla, bone graft, dental implant, ...

  6. Bone structure changes in iliac crest grafts combined with implants

    Verhoeven, Jan Willem; Ruijter, Jan M.; Koole, Ronald; de Putter, Cornelis; Cune, Marco S.

    2010-01-01

    Remodeling of onlay grafts combined with implants to the mandible results in predictable changes in the graft's radiographic density. We studied the relationship between changes in radiographic density and trabecular structure during the first year after onlay grafting with simultaneous implant

  7. Quantifying Long-term Retention of Excised Fat Grafts

    Herly, Mikkel; Ørholt, Mathias; Glovinski, Peter V.

    2017-01-01

    Background: Predicting the degree of fat graft retention is essential whenplanning reconstruction or augmentation with free fat grafting. Most surgeonsobserve volume loss over time after fat grafting; however, the portion lost toresorption after surgery is still poorly defined, and the time to re...

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

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

    2015-01-01

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

  9. Dynamics of solvent-free grafted nanoparticles

    Chremos, Alexandros

    2012-01-01

    The diffusivity and structural relaxation characteristics of oligomer-grafted nanoparticles have been investigated with simulations of a previously proposed coarse-grained model at atmospheric pressure. Solvent-free, polymer-grafted nanoparticles as well as grafted nanoparticles in a melt were compared to a reference system of bare (ungrafted) particles in a melt. Whereas longer chains lead to a larger hydrodynamic radius and lower relative diffusivity for grafted particles in a melt, bulk solvent-free nanoparticles with longer chains have higher relative diffusivities than their short chain counterparts. Solvent-free nanoparticles with short chains undergo a glass transition as indicated by a vanishing diffusivity, diverging structural relaxation time and the formation of body-centered-cubic-like order. Nanoparticles with longer chains exhibit a more gradual increase in the structural relaxation time with decreasing temperature and concomitantly increasing particle volume fraction. The diffusivity of the long chain nanoparticles exhibits a minimum at an intermediate temperature and volume fraction where the polymer brushes of neighboring particles overlap, but must stretch to fill the interparticle space. © 2012 American Institute of Physics.

  10. Mesh-graft urethroplasty: a case report

    田中, 敏博; 滝川, 浩; 香川, 征; 長江, 浩朗

    1987-01-01

    We used a meshed free-foreskin transplant in a two-stage procedure for reconstruction of the extended stricture of urethra after direct vision urethrotomy. The results were excellent. Mesh-graft urethroplasty is a useful method for patients with extended strictures of the urethra or recurrent strictures after several operations.

  11. Fatal Saccharomyces Cerevisiae Aortic Graft Infection

    Meyer, Michael (Technical Monitor); Smith, Davey; Metzgar, David; Wills, Christopher; Fierer, Joshua

    2002-01-01

    Saccharomyces cerevisiae is a yeast commonly used in baking and a frequent colonizer of human mucosal surfaces. It is considered relatively nonpathogenic in immunocompetent adults. We present a case of S. cerevisiae fungemia and aortic graft infection in an immunocompetent adult. This is the first reported case of S. cerevisiue fungemia where the identity of the pathogen was confirmed by rRNA sequencing.

  12. Grafting functional antioxidants on highly crosslinked polyethylene

    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.

  13. Cellular grafts in management of leucoderma

    Mysore Venkataram

    2009-01-01

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

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

    Reza Rezaee

    2017-09-01

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

  15. Rib Bone Graft Adjusted to Fit the Facial Asymmetry: A Frame Structure Graft.

    Lee, Yoon Ho; Choi, Jong Hwan; Hwang, Kun; Choi, Jun Ho

    2015-10-01

    The authors introduce the concept of a "frame structure graft" in which a harvested rib bone was adjusted to fit facial asymmetry. On the costochondral junction of the sixth or seventh rib, a 5 cm incision was made. Through a subperiosteal dissection, the rib bone was harvested. Using a reciprocating saw, the harvested rib was scored on its anterior surface as well as its posterior surface with a partial depth at different intervals. The harvested rib bone was placed on the skin surface of the unaffected side of the face and a curvature was created exactly matching that of the unaffected side by bending the bone using a greenstick fracture. Thereafter, the graft was adjusted to conceal the asymmetry of the deficient side. The adjusted "frame structure" was transferred to the defect through the incisions on the affected side, and the "frame structure" graft was placed on the mandible or zygoma. The graft fixation was done externally with at least 2 Kirschner wires (K-wires). From January 2005 to August 2013, a total of 30 patients (13 men, 17 women, mean age 25.6 years) received a frame structure graft. All 30 patients achieved good healing at the operation site without complications. Donor-site morbidity as pneumothorax from the rib bone harvest was not found. Merits of this frame structure graft, the authors think, are that this method could allow a similar curvature to the normal side. In addition, the procedure itself is easy.

  16. Soft tissue grafting to improve implant esthetics

    Moawia M Kassab

    2010-09-01

    Full Text Available Moawia M KassabDivision of Periodontics, Marquette University, School of Dentistry, Milwaukee, WI, USAAbstract: Dental implants are becoming the treatment of choice to replace missing teeth, especially if the adjacent teeth are free of restorations. When minimal bone width is present, implant placement becomes a challenge and often resulting in recession and dehiscence around the implant that leads to subsequent gingival recession. To correct such defect, the author turned to soft tissue autografting and allografting to correct a buccal dehiscence around tooth #24 after a malpositioned implant placed by a different surgeon. A 25-year-old woman presented with the chief complaint of gingival recession and exposure of implant threads around tooth #24. The patient received three soft tissue grafting procedures to augment the gingival tissue. The first surgery included a connective tissue graft to increase the width of the keratinized gingival tissue. The second surgery included the use of autografting (connective tissue graft to coronally position the soft tissue and achieve implant coverage. The third and final surgery included the use of allografting material Alloderm to increase and mask the implant from showing through the gingiva. Healing period was uneventful for the patient. After three surgical procedures, it appears that soft tissue grafting has increased the width and height of the gingiva surrounding the implant. The accomplished thickness of gingival tissue appeared to mask the showing of implant threads through the gingival tissue and allowed for achieving the desired esthetic that the patient desired. The aim of the study is to present a clinical case with soft tissue grafting procedures.Keywords: case report, connective tissue, dental implants, allograft, coronally positioned flap

  17. Corneal graft reversal: Histopathologic report of two cases

    Qahtani, Abdullah A.; Alkatan, Hind M.

    2014-01-01

    Graft reversal is a rare cause for failed PKP. In this case report we are presenting 2 graft failure cases in which the corneal grafts were reversed unintentionally. The onset of signs of graft failure, however was variable. We have included their clinical course and the histopathologic findings of the removed corneal grafts. A total of 6 cases including ours have been reported so far. The aim of this report is to attract the attention of corneal surgeons to an additional rare cause for faile...

  18. Effect of surface texture of grafted films on antithrombogenicity

    Otsuhata, K.; Razzak, M.T.; Castanares, R.L.; Tabata, Y.; Ohashi, F.; Takkeuchi, A.

    1985-01-01

    The relation between grafting conditions and antithrombogenicity has been examined from the purpose of clearing the necessity of controlling grafting conditions to enhance blood compatibility. The grafting systems employed here were N,N-dimethylacrylamide (DMAA) - poly(tetrafluoroethylene) (PTFE) and DMAA - poly(ethylene-co-tetrafluoroethylene) (AFLON) and grafting parameters were dose rate, monomer concentration and total dose (irradiation time). Grafting DMAA on to the substrates was carried out by using simultaneous irradiation method of gamma rays from a 60 Co source. After evaluation of blood compatibility of the grafted films by using in vitro tests, it has been clear that control of grafting conditions is important. Especially, in both grafting systems, dose rate control has found to be very important for blood compatibility. When higher dose rate of 1.0 x 10 5 to 3.0 x 10 5 rad/hr was used for grafting DMAA on to PTFE or AFLON, blood compatibility of the substrates was not enhanced, whereas it was improved when the grafting was carried out at lower dose rate of 0.97 x 10 4 rad/hr. The correlation between dose rate and antithrombogenicity has been interpreted in terms of surface-roughness of the grafted films. By scanning electron microscope (SEM) - observation, it has been observed that higher dose rate makes the surface rough, whereas lower dose rate makes it smooth. (author)

  19. Evaluation of coronary artery bypass grafts with magnetic resonance imaging

    Okamura, Yoshitaka; Yamada, Yasuyuki; Mochizuki, Yoshihiko; Iida, Hiroshi; Mori, Hideaki; Sugita, You-ichi; Shimada, Kou-ichirou

    1997-01-01

    Currently, the efficacy of magnetic resonance imaging (MRI) for evaluating coronary artery disease has been reported. In this study, we have evaluated the usefulness and the problems of MRI for evaluating the patency of coronary artery bypass grafts. Thirty-five patients who received coronary artery bypass grafting (CABG) were evaluated by using MRI for determining the graft patency compared with conventional coronary angiography. There were 30 men and 5 women. The mean age was 61.2 years (range 45 to 75). The 35 patients had a total of 92 grafts (28 internal thoracic artery, 7 gastroepiploic artery and 57 saphenous vein grafts). Magnetic resonance coronary angiogram (MRCA) was performed with SIGNA HORIZON 1.5 T (GE Inc.) by using 2D-FASTCARD sequence. All patients underwent imaging in the transverse and coronal planes, most had imaging in the sagittal plane, and a few had in the oblique plane. By using MRCA, 82 of 90 grafts were diagnosed correctly as patent, and 1 of 2 grafts were diagnosed correctly as occluded. Thirty-four of 40 LAD grafts (85%), 20 of 22 RCA grafts (91%) and 29 of 30 Cx grafts (97%) were correctly evaluated. The efficacy of MRCA for evaluating the patency of coronary artery bypass grafts was recognized. But the sternal wire (stainless steel) and hemoclip interfere with the interpretation and reduce the sensitivity. Higher sensitivity may be obtained by changing the material of the sternal wires and hemoclips at coronary surgery. (author)

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

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

    1981-01-01

    Radiation-induced grafting of acrylic acid onto high density polyethylene (PE) filaments was carried out in order to raise softening temperature and impart flame retardance and hydrophilic properties. Mutual γ-irradiation method was employed for the grafting in a mixture of acrylic acid (AA), ethylene dichloride and water containing a small amount of ferrous ammonium sulfate. The rate of grafting was very low at room temperature. On the other hand, large percent grafts were obtained when the grafting was performed at an elevated temperature. Activation energy for the initial rate of grafting was found to be 17 kcal/mol between 20 and 60 0 C and 10 kcal/ mol between 60 and 80 0 C. Original PE filament begins to shrink at 70 0 C, shows maximum shrinkage of 50% at 130 0 C and then breaks off at 136 0 C. When a 34% AA graft is converted to metallic salt the graft filament retains its filament form even above 300 0 C and gives maximum shrinkage of 15%. Burning tests by a wire-netting basket method indicate that graft filaments and their metallic salts do not form melting drops upon burning and are self-extinguishing. Original PE filament shows no moisture absorption; however, that of AA-grafted PE increases with increasing graft percent. (author)

  1. [An experimental study of the healing of velour grafts].

    Kobayashi, O

    1986-02-01

    An experimental study of implantation of velour grafts in the abdominal aorta or the external iliac artery of dogs was conducted with the object of evaluating the type of velour surface best fit for small-caliber artery implantation. Velour grafts measuring 4mm in diameter with differing velour surfaces were used as materials. Velour grafts now available on the market differ not only in velour surface but also in structure, notably in porosity and wall thickness. Hence each of the grafts used was reversed (i.e. inside out) and thus new grafts were prepared. These grafts were considered most suitable for making a comparative study of the effects of velour surface on healing. Macroscopic and histological findings revealed that each graft was good healing with the rate of patency as high as 84 percent. However, like Vasculour-D grafts, crimped grafts which preserve the crimp after implantation was significantly thicker at the internal valley than other grafts. Based on the findings of this experimental study non-crimped velour grafts were considered to be best fit for small-caliber artery implantation.

  2. Use of Autologous Scleral Graft in Ahmed Glaucoma Valve Surgery.

    Wolf, Alvit; Hod, Yair; Buckman, Gila; Stein, Nili; Geyer, Orna

    2016-04-01

    To compare the efficacy of an autoscleral free-flap graft versus an autoscleral rotational flap graft in Ahmed glaucoma valve (AGV) surgery. Medical records (2005 to 2012) of 51 consecutive patients (51 eyes) who underwent AGV surgery with the use of either an autoscleral free-flap graft or an autoscleral rotational flap graft to cover the external tube at the limbus were retrieved for review. The main outcome measure was the incidence of tube exposure associated with each surgical approach. Twenty-seven consecutive patients (27 eyes) received a free-flap graft and 24 consecutive patients (24 eyes) received a rotational flap graft. The mean follow-up time was 55.6 ± 18.3 months for the former and 24.2± 5 .0 months for the latter (P<0.0001). Two patients in the free-flap group (8.9%) developed tube exposure at 24 and 55 months postoperatively compared with none of the patients in the rotational flap group. Graft thinning without evidence of conjunctival erosion was observed in 15 patients (55%) in the free-flap group and in 7 patients (29.1%) in the rotational flap group. The use of an autoscleral rotational flap graft is an efficacious technique for primary tube patch grafting in routine AGV surgery, and yielded better results than an autoscleral free-flap graft. Its main advantages over donor graft material are availability and lower cost.

  3. A multilayered polyurethane foam technique for skin graft immobilization.

    Nakamura, Motoki; Ito, Erika; Kato, Hiroshi; Watanabe, Shoichi; Morita, Akimichi

    2012-02-01

    Several techniques are applicable for skin graft immobilization. Although the sponge dressing is a popular technique, pressure failure near the center of the graft is a weakness of the technique that can result in engraftment failure. To evaluate the efficacy of a new skin graft immobilization technique using multilayered polyurethane foam in vivo and in vitro. Twenty-six patients underwent a full-thickness skin graft. Multiple layers of a hydrocellular polyurethane foam dressing were used for skin graft immobilization. In addition, we created an in vitro skin graft model that allowed us to estimate immobilization pressure at the center and edges of skin grafts of various sizes. Overall mean graft survival was 88.9%. In the head and neck region (19 patients), mean graft survival was 93.6%. Based on the in vitro outcomes, this technique supplies effective pressure (skin graft. This multilayered polyurethane foam dressing is simple, safe, and effective for skin graft immobilization. © 2011 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  4. Bone graft viability evaluated by three phase bone scan

    Ljiljana Jaukovic Rajko Spaic; Marijan Novakovic; Srbislav Stosic

    2004-01-01

    Bone defects resulting war injury can be replaced by microvascular bone grafts from fibula. Aim: The aim of this study was to assess the value of three phase (3P) bone scintigraphy in the early detection of the bone graft complications. Method: 3P bone scans were performed in four patients (two after mandible reconstruction with micro vascular fibular bone grafts, one after fibular transplantation for ulnar and one with humeral reconstruction). First dynamic phase scan was performed immediately after iv injection of 740 MBq Tc- 99m DPD, acquiring 15 two seconds duration frames. Second, early static scan was performed during next 300 seconds, and third, delayed scan three hours later. All scans were obtained under the bone graft region. The scans were evaluated using ROI under graft region and the corresponding contra lateral area. Blood flow in graft region was determined using first phase scan, and tracer uptake in the same region was determined using second and third phase scans. Results: in all patients blood flow in graft region was particularly normal. Tracer uptake in one of two patients with mandible reconstruction was diffusely increased in graft, strongly suggesting infection; In the other patient delayed scan showed no tracer uptake in graft center .Both patients with ulnar and humeral reconstruction showed only slightly decreased tracer uptake in bone grafts. 3 phase bone scintigraphy may play a role in the evaluation of bone graft viability by predicting the infection and necrosis. (authors)

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

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

    2016-01-01

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

  6. Synthesis of graft copolymers onto starch and its semiconducting properties

    Nevin Çankaya

    Full Text Available 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. Keywords: Starch, Graft copolymer, Semiconducting, Thermal stability, Starch methacrylate

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

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

    1999-08-01

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

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

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

    1987-01-01

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

  9. Radiation induced graft copolymerization of acrylamide onto poly (3-hydroxybutyrate)

    Gonzalez Torres, Maykel; Rapado Paneque, Manuel; Paredes Zaldivar, Mayte; Altanes Valentin, Sonia; Barrera Gonzalez, Gisela

    2008-01-01

    The graft copolymer poly (3-hydroxybutyrate)-g- polyacrylamide [P (HB-g-AAm)] was synthesized by radiation induced graft copolymerization of acrylamide onto poly (3-hydroxybutyrate). The study was conducted by the simultaneous irradiation method. The structure of [P (HB-g-AAm)] was identified by Fourier Transform Infrared (FTIR) spectroscopy. Thermal behavior of the graft copolymer was also studied by Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). From the results it was found that FTIR studies showed new signals (stretching -N-H) as strong evidence of grafting. The grafting degree was found to be 10 % and the thermodynamic parameter obtained from the DSC thermogram of plain PHB and the graft copolymer varied showing decrease in the material crystallinity and increase in the glass transition temperature. These results demonstrate that the radiation induced graft copolymerization reaction of acrylamide onto PHB was successively achieved. (Author)

  10. Permeability of solutes through cellophanes grafted with vinyl monomers. II. Diffusion of potassium chloride through cellophanes grafted with acrylic acid

    Takigami, S.; Maeda, Y.; Nakamura, Y.

    1979-01-01

    The permeability behavior of potassium chloride through cellophane grafted with acrylic acid by a γ-irradiation method was studied by the theoretical equation derived from the phenomenological equation and compared with the results of Donnan membrane equilibrium. It was shown that the permeation of potassium chloride through the grafted cellophanes exhibited behavior typical of a polyionic membrane for grafts of more than 55% but depended on the permeability of both cellophane and graft regions for lower percents of grafting. It was found that the dominant factor affecting the permeation of potassium chloride was an effective concentration of fixed charge in the membrane. 5 figures, 2 tables

  11. Intravascular stent graft with polyurethane and metallic stent: experimental study

    Do, Young Soo; Lee, Won Jae; Kim, Boo Kyung Han; Park, Jae Hyung; Lee, Hak Jong; Lee, Sang Hyun; Kim, Sung Hyun; Kim, Jong Won; Ha, Jongwon

    1997-01-01

    To evaluate the usefulness of a new model of the stent graft, and of tissue response related to placement of the stent graft. The stent graft was constructed from polyurethane (Pellethane) graft and Hanaro stent(12mm in diameter, 45mm in length, 10 bends). A stent grafts was inserted into the lower thoracic aorta in each of six adult mongrel dogs(body weight, 12-16kg). At one, two, four, and six months, follow-up studies of angiography and spiral CT angiography were preformed to evaluate wascular patency, vascular stenosis, and thrombus formation. Two dogs were sacrificed at 1month, 2months, and 6months after insertion of the stent graft and macroscopic, light microscopic, and scanning electron microscopic examinations of the aortic segment including the stent graft were performed to evaluate intimal hyperplasia, endothelial growth to the graft, and thrombus formation. During follow-up at one, two, four, and six months, angiography or spiral CT angiography showed 20-100% luminal stenosis or occlusion of the lower thoracic aorta by the thrombus and perigraft leaks in three dogs(50%), and collateral vessels caused by occlusion of the aorta in two (33.3%). On gross examination, there were thrombi of 1-5mm thickness at the graft portions in all dogs, and this thickness gradually increased. The mean thickness of intimal hyperplasia at the stent portion gradually increased from 120μm to 227μm and the mean thickness of intimal hyperplasia at the graft portion from 93μm to 914μm. This thickness was greater at the graft portion than at the stent portion. Scanning electron microscopy showed elliptical endothelial lining on the neointimal surfaces at each end of the graft. Thrombi caused stenosis or occlusion of the stent graft. In order for such a graft to be ideal, further study is needed

  12. Graft copolymers of polypropylene films. 1. radiation induced grafting of mixed monomers. Vol. 3

    El-Salmawi, K.M.; El-Naggar, A.M.; Said, H.M.; Zahran, A.H.

    1996-01-01

    Radiation graft copolymerization of co monomer mixtures of acrylic acid (AAC), and styrene (S) onto polypropylene (PP) film by mutual method has been investigated. The effects of different factors that may affect the grafting yield such as inhibitor concentration (Mohr's salt), solvent composition (MeOH and H 2 O), radiation dose and dose rate were considered. It was found that the role of Mohr's salt is very effective when the ratio of AAC in the co monomer mixtures was at lower values. However, the addition of 1.25 Wt% of Mohr's salt reduced the homo polymer formation and enhances the grafting process. Graft copolymerization in presence of solvent mixture composed of methanol and water was found to afford higher grafting than in pure methanol regardless of the composition of the co monomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20% H 2 O:80%MeOH and a co monomer mixture of 20%AAC:80%sty. An attempt was made to determine each PAAC and PS fractions in the total graft yield obtained. Two methods of analysis based on using the reactivity ratios reported in literature, elemental analysis and IR spectroscopy. The determination of poly (acrylic acid) and polystyrene fractions by elemental analysis is believed more accurate than these by reactivity ratio. The precise results obtained by elemental analysis with respect to the chemical structure of known polymer prepared under identical conditions. The results obtained by IR measurements go well with that obtained with the reactivity ratio methods. 5 figs., 3 tabs

  13. Graft copolymers of polypropylene films. 1. radiation induced grafting of mixed monomers. Vol. 3

    El-Salmawi, K M; El-Naggar, A M; Said, H M; Zahran, A H [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo, (Egypt)

    1996-03-01

    Radiation graft copolymerization of co monomer mixtures of acrylic acid (AAC), and styrene (S) onto polypropylene (PP) film by mutual method has been investigated. The effects of different factors that may affect the grafting yield such as inhibitor concentration (Mohr`s salt), solvent composition (MeOH and H{sub 2} O), radiation dose and dose rate were considered. It was found that the role of Mohr`s salt is very effective when the ratio of AAC in the co monomer mixtures was at lower values. However, the addition of 1.25 Wt% of Mohr`s salt reduced the homo polymer formation and enhances the grafting process. Graft copolymerization in presence of solvent mixture composed of methanol and water was found to afford higher grafting than in pure methanol regardless of the composition of the co monomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20% H{sub 2} O:80%MeOH and a co monomer mixture of 20%AAC:80%sty. An attempt was made to determine each PAAC and PS fractions in the total graft yield obtained. Two methods of analysis based on using the reactivity ratios reported in literature, elemental analysis and IR spectroscopy. The determination of poly (acrylic acid) and polystyrene fractions by elemental analysis is believed more accurate than these by reactivity ratio. The precise results obtained by elemental analysis with respect to the chemical structure of known polymer prepared under identical conditions. The results obtained by IR measurements go well with that obtained with the reactivity ratio methods. 5 figs., 3 tabs.

  14. The impact of slow graft function on graft outcome is comparable to delayed graft function in deceased donor kidney transplantation.

    Shin, Jung-Ho; Koo, Eun Hee; Ha, Sung Hae; Park, Ji Hyeon; Jang, Hye Ryoun; Lee, Jung Eun; Park, Jae-Berm; Kim, Sung Joo; Jung, Sin-Ho; Kim, Yoon-Goo; Kim, Dae Joong; Oh, Ha Young; Huh, Wooseong

    2016-03-01

    Slow graft function (SGF) can influence overall prognosis in patients receiving deceased donor kidney transplantation (DKT). However, the impact of SGF on renal function remains uncertain. We investigated retrospectively renal function in cases with SGF compared with early graft function (EGF) and delayed graft function (DGF). Renal function after transplantation was analyzed in 199 patients who underwent DKT. Patients were classified into 130 (65.3 %) cases with EGF, 27 (13.6 %) cases with SGF, 6 (3.0 %) cases with DGF and one dialysis (DGF1), and 36 (18.1 %) cases with DGF and two or more dialyses (DGF2). The 1-year estimated glomerular filtration rate (eGFR) in the SGF group was lower than that in the EGF group (P = 0.027), but the rate of eGFR decline did not differ between the groups. The risk factors for renal function were evaluated using the area under the eGFR curve over 3 years (AUCeGFR). Donor age was negatively, and recipient age and the number of HLA matches were positively correlated with the AUCeGFR (all P DKT. Moreover, it was comparable to DGF. Efforts should be dedicated to minimizing the development of SGF and DGF.

  15. Comparison of mesencephalic free-floating tissue culture grafts and cell suspension grafts in the 6-hydroxydopamine-lesioned rat

    Meyer, Morten; Widmer, H R; Wagner, B

    1998-01-01

    of grafted dopaminergic neurons and to correlate that with the behavioral effects. Additional cultures and acutely prepared explants were also fixed and stored for histological investigation in order to estimate the loss of dopaminergic neurons in culture and after transplantation. Similar behavioral...... numbers of TH-immunoreactive (TH-ir) neurons in grafts of cultured tissue (775 +/- 98, mean +/- SEM) and grafts of fresh, dissociated cell suspension (806 +/- 105, mean +/- SEM). Cell counts in fresh explants, 7-day-old cultures, and grafted cultures revealed a 68.2% loss of TH-ir cells 7 days after......Ventral mesencephalon (VM) of fetal rat and human origin grown as free-floating roller-tube (FFRT) cultures can survive subsequent grafting to the adult rat striatum. To further explore the functional efficacy of such grafts, embryonic day 13 ventral mesencephalic tissue was grafted either after 7...

  16. Assessment of the viability of skin grafts

    Wahner, H.W.

    1988-01-01

    A number of tests are available to monitor the blood flow in free and distant pedicle skin grafts. The information from these tests aids in the development of measures to enhance vascularization and is occasionally needed to make clinical decisions in patients with distant pedicle grafts. Measurements of the disappearance of an intradermally injected small amount of 133 Xe allows determination of a clearance rate and blood flow before and after clamping the original blood supply through the base. With /sup 99m/Tc, which is generally more readily available, a flow index and block index can be determined. Clinically both procedures give equally good results in determining a safe time for pedicle base separation. The fluorescein test allows assessment of regional blood flow distribution within the pedicle

  17. Novel anterior cruciate ligament graft fixation device reduces slippage

    Lopez MJ

    2013-05-01

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

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

    Jansen, B.; Ellinghorst, G.

    1985-01-01

    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

  19. LATE RENAL GRAFT REJECTION: PATHOLOGY AND PROGNOSIS

    E.S. Stolyarevich

    2014-01-01

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

  20. Hydrogen, a potential safeguard for graft-versus-host disease and graft ischemia-reperfusion injury?

    Yuan, Lijuan; Shen, Jianliang

    2016-01-01

    Post-transplant complications such as graft-versus-host disease and graft ischemia-reperfusion injury are crucial challenges in transplantation. Hydrogen can act as a potential antioxidant, playing a preventive role against post-transplant complications in animal models of multiple organ transplantation. Herein, the authors review the current literature regarding the effects of hydrogen on graft ischemia-reperfusion injury and graft-versus-host disease. Existing data on the effects of hydrogen on ischemia-reperfusion injury related to organ transplantation are specifically reviewed and coupled with further suggestions for future work. The reviewed studies showed that hydrogen (inhaled or dissolved in saline) improved the outcomes of organ transplantation by decreasing oxidative stress and inflammation at both the transplanted organ and the systemic levels. In conclusion, a substantial body of experimental evidence suggests that hydrogen can significantly alleviate transplantation-related ischemia-reperfusion injury and have a therapeutic effect on graft-versus-host disease, mainly via inhibition of inflammatory cytokine secretion and reduction of oxidative stress through several underlying mechanisms. Further animal experiments and preliminary human clinical trials will lay the foundation for hydrogen use as a drug in the clinic. PMID:27652837

  1. A study on the morphology of polystyrene-grafted poly(ethylene-alt-tetrafluoroethylene) (ETFE) films prepared using a simultaneous radiation grafting method

    Song, Ju-Myung; Ko, Beom-Seok; Sohn, Joon-Yong; Nho, Young Chang; Shin, Junhwa

    2014-01-01

    The morphology of polystyrene-grafted poly(ethylene-alt-tetrafluoroethylene) (ETFE) films prepared using a simultaneous radiation grafting method was investigated using DMA, DSC, XRD, and SAXS instruments. The DMA study indicates that the ETFE amorphous phase and PS amorphous phase are mixed well in the PS-grafted ETFE films while the ETFE crystalline phase and the PS amorphous phase are separated, suggesting that the PS chains are grafted mainly on the ETFE amorphous regions. The DSC and XRD data showed that the natural crystalline structures of ETFE in the grafted ETFE films are not affected by the degree of grafting. The SAXS profiles displayed that the inter-crystalline distance of the ETFE films increases with an increasing degree of grafting, which further implies that the PS graft chains formed by the simultaneous irradiation has a significant impact on the amorphous morphology of the resulting grafted ETFE film. Thus, these results indicate that the styrene monomers are mainly grafted on the ETFE amorphous regions during the simultaneous radiation grafting process. - Highlights: • PS-grafted ETFE films were prepared by a simultaneous radiation grafting method was investigated. • The natural crystalline structures of grafted ETFE films are not affect by the degree of grafting. • The inter-crystalline distance of the ETFE films increase with increasing degree of grafting. • The styrene monomers are mainly grafted on the ETFE amorphous regions during a simultaneous radiation grafting using gamma-ray

  2. The effect of carbon dioxide therapy on composite graft survival.

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino, Ruy de Souza; Sousa, João Batista de

    2013-08-01

    To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, histopathology features and histomorphometry of collagen. The treated group had a significantly lower weight gain (p=0.038). Histopathology was not significantly different between groups. There was an increase in amount of collagen in 2 cm grafts submitted to carbon dioxide therapy (p=0.003). Carboxytherapy didn't influence graft survival rate for 1.5 cm grafts or 2 cm grafts (p=0.567 and p=0.777, respectively). Carbon dioxide therapy increased the amount of collagen in 2 cm grafts. CO2 was not significantly different from saline infusion on composite grafts survival, but this study suggests that there is a mechanical effect caused by distension which favored graft survival.

  3. Radiation-induced grafting of TMPM onto polypropylene

    Wang Huiliang; Li Hong; Chen Wenxiu

    1995-01-01

    The gamma radiation-induced graft copolymerization of 2,2,6,6-tetramethyl-4-piperidinyl-methacrylate (TMPM), a very effective hindered amine light stabilizer (HALS), onto polypropylene was investigated by simultaneous- irradiation technique. The various synthesis conditions on the graft content was studied. It was found that benzene, CCl 4 and petroleum ether are more effective than other solvents, the percent grafting reached 7.1% for benzene. The percent grafting is higher when graft copolymerization is carried out in argon atmosphere than those in air. For all the grafting copolymerization carried out in benzene and CCl 4 , percent grafting increase linearly from 1 to 5 Mrad and beyond 5 Mrad, a tendency to level off appeared. At a constant dose, the percent grafting was found to be higher at high dose rate until 228 rad/s. Percent grafting also increased continuously with increasing monomer concentration up to 2.85 mol/L, but significant increase in grafting was observed only up to 1.14 mol/L

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

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

    1984-01-01

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

  5. PRFM enhance wound healing process in skin graft.

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

    2014-12-01

    Facial plastic and reconstructive surgery often used skin graft on defects that cannot be covered primarily by a local flap. However, wound healing using skin graft is slow, most of the time the graft is contractured and the take of graft is not optimal. Platelet rich fibrin matrix (PRFM) is a new generation of concentrated platelets that produce natural fibrin and reported to speed up the healing process. Application of PRFM in the skin graft implants is expected to increase the survival of the graft. We used porcine as animal models to elucidate the effect of autologous PRFM on wound healing in full-thickness (FTSG) and split-thickness (STSG) skin grafts. Survival level of the skin graft was determined by using ImageJ software based on the formation of collagen type 1 and graft take. We observed that the use of PRFM in FTSG and STSG increased type 1 collagen formation. We also found that PRFM addition in STSG gave the best skin graft take. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  6. Primary contraction of skin grafts: a porcine preliminary study

    Alexander Bogdanov Berezovsky

    2015-03-01

    Full Text Available Aim: Skin grafting is a common clinical practice for plastic surgeons, yet primary contraction of these grafts is a neglected topic. This study was designed to investigate primary contraction and introduce the shape of skin graft as a possible factor that modifies primary contraction behavior, using porcine models. Methods: In the first series, full-thickness skin grafts (FTSGs and split-thickness skin grafts (STSGs were compared. In a second series, how the shape of the skin graft affected the degree of contraction was examined. Results: The mean percentage of FTSG shrinkage was 12.04%, and the median was 12.18%. The mean percentage of STSG shrinkage was 6.87%, and the median was 5%. Circle-shaped and square-shaped FTSGs showed mean/median graft shrinkage of 5.83%/6.93% and 4.15%/3.75%, respectively. In STSGs, the circle-shaped and square-shaped grafts had mean/median graft shrinkage of 1.07%/0% and 0.31%/0%, respectively. Conclusion: Our preliminary report revealed an expected greater shrinkage of FTSGs compared with STSGs. Furthermore, in a limited number of specimens, the shape of the skin graft seemed to affect the primary contraction of the STSGs.

  7. Calcification of a Synthetic Renovascular Graft in a Child

    D.S.T. Chong

    Full Text Available : Introduction: Vascular grafts, especially in paediatric cases, need to be durable. Common failures such as thrombosis are well documented with research efforts directed towards them. However, there are lesser known causes of graft failure, such as graft calcification, and these also require further research focus. Report: A paediatric case is described in which a synthetic renovascular graft, implanted for mid-aortic syndrome, became calcified, necessitating surgical intervention to resolve graft malfunction. Significant calcification in the limb of a bifurcated polyethylene terephthalate graft was found to be the cause of resistant stenosis and refractory hypertension. Histology conducted on the explanted limb showed the presence of multinuclear giant cells, indicating a chronic foreign body response. Discussion: Calcification of vascular grafts is probably more common than previously recognised. Stenosis typically resistant to angioplasty may result in the long term and thus leading to surgical intervention. In young children, this is suboptimal as these grafts need to last throughout adulthood. Explanted prosthetic grafts should be sent to specialist registries such as that in Strasbourg to be optimally assessed so that contributory factors can be identified. Keywords: Renovascular graft, Paediatric, Calcification

  8. GRAFT TAKES OF TOMATO ON OTHER SOLANACEOUS PLANTS

    ANDRÉ RICARDO ZEIST

    2017-01-01

    Full Text Available This paper aimed to assess tomato grafting on different solanaceous species through two grafting methods. Scions were cut from cultivar Santa Cruz Kada seedlings. A fully randomized experimental design was carried out with treatments in a 9 x 2 factorial scheme. As rootstocks, four accessions of mini - tomatoes (0224 - 53, RVTC 57, RVTC 20 and 6889 - 50 - Solanum lycopersicum L; two species of wild tomato ( Solanum habrochaites var hirsutum ‘PI - 127826’ and Solanum pennellii ‘LA716’; other two tomato species [ Solanum, cocona ( Solanum sessiliflorum and physalis ( Physalis peruviana ] and a control with cultivar Santa Cruz Kada (auto - graft rootstocks were used. In addition, two grafting methods were evaluated full cleft and approach graft. Fifteen days after grafting, plants were assessed for graft - take percentage; root length; plant height; leaf number; foliar area; root, stem and leaf dry matter; and ratio between shoot and root dry matter. Based on the results, we may state rootstock and grafting interaction had effect on both graft - take rate and plant development. Overall, the studied plants should be recommended as rootstock, except for 6889 - 50 mini - tomato ( S. lycopersicum L. and S. pennellii . Full cleft grafting was most suitable for cocona and physalis, while the approach method showed better results for the mini - tomato accessions 0224 - 53, RVTC 57 and RVTC 20, as well as for S. habrochaites .

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

    Bryce M Whited

    Full Text Available Bioengineering of vascular grafts holds great potential to address the shortcomings associated with autologous and conventional synthetic vascular grafts used for small diameter grafting procedures. Lumen endothelialization of bioengineered vascular grafts is essential to provide an antithrombogenic graft surface to ensure long-term patency after implantation. Conventional methods used to assess endothelialization in vitro typically involve periodic harvesting of the graft for histological sectioning and staining of the lumen. Endpoint testing methods such as these are effective but do not provide real-time information of endothelial cells in their intact microenvironment, rather only a single time point measurement of endothelium development. Therefore, nondestructive methods are needed to provide dynamic information of graft endothelialization and endothelium maturation in vitro. To address this need, we have developed a nondestructive fiber optic based (FOB imaging method that is capable of dynamic assessment of graft endothelialization without disturbing the graft housed in a bioreactor. In this study we demonstrate the capability of the FOB imaging method to quantify electrospun vascular graft endothelialization, EC detachment, and apoptosis in a nondestructive manner. The electrospun scaffold fiber diameter of the graft lumen was systematically varied and the FOB imaging system was used to noninvasively quantify the affect of topography on graft endothelialization over a 7-day period. Additionally, results demonstrated that the FOB imaging method had a greater imaging penetration depth than that of two-photon microscopy. This imaging method is a powerful tool to optimize vascular grafts and bioreactor conditions in vitro, and can be further adapted to monitor endothelium maturation and response to fluid flow bioreactor preconditioning.

  10. Electron beam induced modification of grafted polyamides

    Timus, D.M.; Brasoveanu, M.M.; Bradley, D.A.; Popov, A.M.

    1998-01-01

    It is well known that irradiation, when applied on its own or in combination with other physical and chemical treatments, can manifest in radiation damage to materials. Radiation processing technology focuses upon producing favourable modification of materials through use of relatively high dose and dose rates. Current interest is in modifying the thermal and electrical properties of textured polymers in an effort to improve safety and wear comfort of clothing. No less important is the production of textiles which are safe to use, both in homes and offices. Present investigations provide additional data in support of findings which show that polyamides, a particular class of textured polymer, are amenable to radiation processing. Accelerated electron beam irradiation of sheets of polyamide fibre results in induced grafting of acrylic and methacrylic acids. The degree of grafting is critically dependent upon irradiation dose and the extent of monomers dilution. Of particular importance is the high correlation which is found between degree of grafting and a decrease in the softening rate of the modified polyamide. A systematic modification of electrical conductivity is also observed. (author)

  11. Bladder Mucosal Graft Vaginoplasty: A Case Report.

    Chiaramonte, Cinzia; Vestri, Elettra; Tripi, Flavia; Giannone, Antonino Giulio; Cimador, Marcello; Cataliotti, Ferdinando

    2018-06-18

    Female vaginoplasty reconstruction, by choice, is usually performed with adjacent tissue. However in some clinical conditions such as high urogenital confluence sinus, cloacal malformation with extreme vaginal hypoplasia, local tissue may not be available. When vaginal replacement is performed in pediatric patients intestinal segments is preferred to non-operative procedures that require continuative dilations. However mucus production, malignant transformation risk and diversion colitis are important side effects. We present a nouvel technique for vaginoplasty in a female child presenting with an isolated urogenital sinus malformation without virilization. The patient at 20 months underwent vaginoplasty using tubularized bladder mucosal graft. Surgical procedure was devoid of complications. Pubertal development occurred at age of 15. She underwent regular follow up until 18 years of age. At this age we performed clinical evaluation: absence of vaginal introitus stenosis and good cosmetic results were observed. Then she underwent vaginoscopy with multiple biopsies. Pathology examination of the bladder mucosal graft evidenced a normal structure of the mucosa, with a stratified squamous epithelium. Different techniques are taken into account for vaginal reconstruction according to the severity and to the type of malformation. We describe the use of bladder mucosal graft with favorable results after long term follow-up. Copyright © 2018. Published by Elsevier Inc.

  12. Allogeneic bone marrow grafts in genotyped swine

    Vaiman, M.

    1974-01-01

    The proof of a major histocompatibility complex (MHC) called SL-A enabled to promote bone marrow allografts. A study of the response to that kind of graft in irradiated pig states a number of interesting points. Bone marrow allografting complies with the rule of tissular compatibility with the major histocompatibility complex. The taking of SL-A incompatible bone marrow allografts could not be achieved under the experimental conditions. In spite of the high doses of radiation, 950 to 1050 rads, higher than 1.5 LD 100%, recipients were capable of rejecting their grafts, regularly. SL-A identify ensured 100%, initial achievement. However, animals developed regular fatal disease within a fairly short time. This development could by no means, be ascribed to the sole sequealae of radiation sickness since autografted animals at equal or even higher doses, showed none of the symptome. Assumption of a chronic graft-vs-host reactions, induced by the minor histocompatible systems, was put foreward, but should be confirmed histopathologically [fr

  13. Graft fixation in cruciate ligament reconstruction.

    Brand, J; Weiler, A; Caborn, D N; Brown, C H; Johnson, D L

    2000-01-01

    Cruciate ligament reconstruction has progressed dramatically in the last 20 years. Anatomic placement of ligament substitutes has fostered rehabilitation efforts that stress immediate and full range of motion, immediate weightbearing, neuromuscular strength and coordination, and early return to athletic competition (3 months). This has placed extreme importance on secure graft fixation at the time of ligament reconstruction. Current ligament substitutes require a bony or soft tissue component to be fixed within a bone tunnel or on the periosteum at a distance from the normal ligament attachment site. Fixation devices have progressed from metal to biodegradable and from far to near-normal native ligament attachment sites. Ideally, the biomechanical properties of the entire graft construct would approach those of the native ligament and facilitate biologic incorporation of the graft. Fixation should be done at the normal anatomic attachment site of the native ligament (aperture fixation) and, over time, allow the biologic return of the histologic transition zone from ligament to fibrocartilage, to calcified fibrocartilage, to bone. The purpose of this article is to review current fixation devices and techniques in cruciate ligament surgery.

  14. Ion exchange fiber by radiation grafting, 1

    Fujiwara, Kunio

    1990-01-01

    Radiation grafting is gaining attention as a method for producing high performance materials. This method can be applied to add functions to existing polymer plastics. The author participated in the research program on the production of ion exchange fiber by radiation grafting and its applicability at the Japan Atomic Energy Research Institute, Takasaki Radiation Chemistry Research Establishment. Consequently, it was clarified that it was possible to introduce the cation exchange group, represented by sulfonic and carboxyl groups, and the anion exchange group, represented by the quarternary ammonium group, to polypropylene fiber available on the market. The ion exchange capacity was able to be controlled by the degree of grafting, i.e. approximately up to 3 meq/g in both strong acid and strong base and approximately up to 5 meq/g in weak acid were obtained. The adsorption performance of ammonia, a representative malodorous substance, was also studied using test cation exchange fiber. The adsorption rate of H type strong acid cation exchange fiber was great, due to the H type having neutral reaction, and the adsorption capacity matched the ion exchange capacity. Although the Cu and Ni types features coordinated adsorption and their adsorption rates were from 1/2 to 1/3 of that of the H type, their adsorption capacities showed increase along with the metal adsorbed. (author)

  15. Allogenic lyophilized cartilage grafts for craniomaxillofacial reconstruction

    Pill Hoon Choung

    1999-01-01

    Allogenic lyophilized cartilages were made in our clinic after Sailer methods and some modification. In our clinic, we have used allogenic cartilage grafts on 102 defects of craniomaxillofacial area; 1) for defects from cyst or ameloblastoma, 2) for lack of continuity of the mandible, 3) for rhinoplasty, 4) for paranasal augmentation, 5) for augmentation genioplasty, 6) for reconstruction of orbital floor, 7) for oroantral fistula, 8) for temporal augmentation, 9) for TMJ surgery 10) for condyle defect as a costochondral graft, 11) for filling of tooth socket and alveolus augmentation,12) for correction or orbital height and 13) for guided bone regeneration in peripheral implant. The types of lyophilized cartilage used were chip, sheet and block types developed by freeze-dried methods. Some grafts showed change of ossification, in which case we could perform implant on it. We have good results on reconstruction of craniomaxillofacial defects. Allogenic cartilage have advantages such as 1) it has no immune reaction clinically, 2) it is more tolerable to infection than that of autogenous cartilage, 3) it has character of less resorption which require no over correction, 4) it is easy to manipulate contouring, and 5) it has possibility of undergoing ossification. Allogenic cartilage has been considered as good substitutes for bone. The author would like to report the results on 102 allogenic cartilage have

  16. Vascularized nerve grafts: an experimental study.

    Donzelli, Renato; Capone, Crescenzo; Sgulò, Francesco Giovanni; Mariniello, Giuseppe; Maiuri, Francesco

    2016-08-01

    The aim of this study is to define an experimental model in order to promote the functional recovery of the nerves using grafts with vascular support (Vascular Nerve Grafts - VNG). The aim of this study is to define, on an experimental model in normal recipient bed, whether the functional recovery with VNG is superior to that obtained non-vascularized graft (NNG). Twenty male rabbits, which underwent dissection of sciatic nerve, were later treated by reinnervation through an autograft. In 10 animals the reconstruction of sciatic nerve was realized with VNG; in 10 control animals the reconstruction of sciatic nerve was realized with NNG. The VNG group showed a better axonal organization and a significantly higher number of regenerated axons in the early phases (after 30 days) than the NNG group, whereas the difference in the axonal number at day 90 was less significant; besides, the axon diameter and the myelin thickness were not significantly improved by VNG group. Our data suggests that the use of VNG leads to a faster regeneration process and a better functional recovery, although the final results are comparable to those of the NNG. VNG improve the quality of the axonal regeneration (axonal diameter and Schwann cells), although the increase in the axonal number is not significant and does not improve the long-term functional outcome.

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

    Vollet Filho, José D.; da Silveira, Marina R.; Castro-e-Silva, Orlando; Bagnato, Vanderlei S.; Kurachi, Cristina

    2015-06-01

    Evaluating transplantation grafts at harvest is essential for its success. Laser-induced fluorescence spectroscopy (LIFS) can help monitoring changes in metabolic/structural conditions of tissue during transplantation. The aim of the present study is to correlate LIFSobtained spectra of human hepatic grafts during liver transplantation with post-operative patients' mortality rate and biochemical parameters, establishing a method to exclude nonviable grafts before implantation. Orthotopic liver transplantation, piggyback technique was performed in 15 patients. LIFS was performed under 408nm excitation. Collection was performed immediately after opening donor's abdominal cavity, after cold perfusion, end of back-table period, and 5 min and 1 h after warm perfusion at recipient. Fluorescence information was compared to lactate, creatinine, bilirubin and INR levels and to survival status. LIFS was sensitive to liver changes during transplantation stages. Study-in-progress; initial results indicate correlation between fluorescence and life/death status of patients.

  18. CMR diagnosis of coronary graft fistula

    Bengt Johansson

    2014-01-01

    Full Text Available The patient is a 54-year old man with a previous history of cerebral aqueduct stenosis and hydrocephalus resulting in malignant hypertension who had surgery for permanent ventriculo-peritoneal shunt. At age 41, he had coronary artery bypass graft (CABG surgery with the right internal mammary artery anastomosed to the posterior descending artery and a saphenous vein graft to the first obtuse marginal branch. The patient was recently admitted with pneumonia that rapidly deteriorated and he went in respiratory failure requiring mechanical ventilation. A thoracic CT investigation showed massive bilateral pulmonary infiltrates, pulmonary artery embolism and a large vein graft aneurysm with a maximal diameter of 40 mm (Figure 1 A-B. The management course was complicated with prolonged respiratory failure, persistent infection, despite negative cultures and extended hospital stay. After 50 days of slow recovery the patient was discharged with a need for home oxygen therapy. Ten days later, he was re-admitted with chest pain requiring admission to the coronary care unit where severe pulmonary hypertension was diagnosed with Doppler echocardiography. Troponin-T was mildly elevated, 1,3 ug/L (ref <0,01, CRP was 50 mg/L and chest X-ray showed bilateral lung infiltrates and wide pulmonary vessels. At this point a systo-diastolic murmur was heard at the left lower sternal edge. With a view of potential coronary reintervention and to evaluate the pulmonary hypertension, a coronary angiogram and a pulmonary artery cathetherisation were performed. This showed a new stenosis in the left anterior descending coronary artery and the pulmonary catheterisation showed a “step-up” in oxygen saturation in the pulmonary artery, suggesting a left-to-right shunt. The vein graft aneurysm did not contribute to the coronary circulation. A cardiovascular magnetic resonance scan revealed a communication between the vein graft aneurysm and the left branch pulmonary artery

  19. Configuration affects parallel stent grafting results.

    Tanious, Adam; Wooster, Mathew; Armstrong, Paul A; Zwiebel, Bruce; Grundy, Shane; Back, Martin R; Shames, Murray L

    2018-05-01

    A number of adjunctive "off-the-shelf" procedures have been described to treat complex aortic diseases. Our goal was to evaluate parallel stent graft configurations and to determine an optimal formula for these procedures. This is a retrospective review of all patients at a single medical center treated with parallel stent grafts from January 2010 to September 2015. Outcomes were evaluated on the basis of parallel graft orientation, type, and main body device. Primary end points included parallel stent graft compromise and overall endovascular aneurysm repair (EVAR) compromise. There were 78 patients treated with a total of 144 parallel stents for a variety of pathologic processes. There was a significant correlation between main body oversizing and snorkel compromise (P = .0195) and overall procedural complication (P = .0019) but not with endoleak rates. Patients were organized into the following oversizing groups for further analysis: 0% to 10%, 10% to 20%, and >20%. Those oversized into the 0% to 10% group had the highest rate of overall EVAR complication (73%; P = .0003). There were no significant correlations between any one particular configuration and overall procedural complication. There was also no significant correlation between total number of parallel stents employed and overall complication. Composite EVAR configuration had no significant correlation with individual snorkel compromise, endoleak, or overall EVAR or procedural complication. The configuration most prone to individual snorkel compromise and overall EVAR complication was a four-stent configuration with two stents in an antegrade position and two stents in a retrograde position (60% complication rate). The configuration most prone to endoleak was one or two stents in retrograde position (33% endoleak rate), followed by three stents in an all-antegrade position (25%). There was a significant correlation between individual stent configuration and stent compromise (P = .0385), with 31

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

    Zixuan Wang

    2016-08-01

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

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

    Edelstein, M.; Plaut, Z.; Ben-Hur, M.

    2011-01-01

    The effects of grafting on Na and Cl– uptake and distribution in plant tissues were quantified in a greenhouse experiment using six combinations of melon (Cucumis melo L. cv. Arava) and pumpkin (Cucurbita maxima Duchesne×Cucurbita moschata Duchesne cv. TZ-148): non-grafted, self-grafted, melons grafted on pumpkins, and pumpkins grafted on melons. Total Na concentration in shoots of plants with pumpkin or melon rootstocks was 400 mmol kg−1, respectively, regardless of the scion. In contrast, shoot Cl– concentrations were quite similar among the different scion–rootstock combinations. Na concentrations in exudates from cut stems of plants with a pumpkin rootstock were very low (<0.18 mM), whereas those in the exudates of plants with melon rootstocks ranged from 4.7 mM to 6.2 mM, and were quite similar to the Na concentration in the irrigation water. Root Na concentrations averaged 11.7 times those in the shoots of plants with pumpkin rootstocks, while in plants with melon rootstocks, values were similar. Two mechanisms could explain the decrease in shoot Na concentrations in plants with pumpkin rootstocks: (i) Na exclusion by the pumpkin roots; and (ii) Na retention and accumulation within the pumpkin rootstock. Quantitative analysis indicated that the pumpkin roots excluded ∼74% of available Na, while there was nearly no Na exclusion by melon roots. Na retention by the pumpkin rootstocks decreased its amount in the shoot by an average 46.9% compared with uniform Na distribution throughout the plant. In contrast, no retention of Na could be found in plants grafted on melons. PMID:20729482

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

    Edelstein, M; Plaut, Z; Ben-Hur, M

    2011-01-01

    The effects of grafting on Na and Cl(-) uptake and distribution in plant tissues were quantified in a greenhouse experiment using six combinations of melon (Cucumis melo L. cv. Arava) and pumpkin (Cucurbita maxima Duchesne×Cucurbita moschata Duchesne cv. TZ-148): non-grafted, self-grafted, melons grafted on pumpkins, and pumpkins grafted on melons. Total Na concentration in shoots of plants with pumpkin or melon rootstocks was 400 mmol kg(-1), respectively, regardless of the scion. In contrast, shoot Cl(-) concentrations were quite similar among the different scion-rootstock combinations. Na concentrations in exudates from cut stems of plants with a pumpkin rootstock were very low (<0.18 mM), whereas those in the exudates of plants with melon rootstocks ranged from 4.7 mM to 6.2 mM, and were quite similar to the Na concentration in the irrigation water. Root Na concentrations averaged 11.7 times those in the shoots of plants with pumpkin rootstocks, while in plants with melon rootstocks, values were similar. Two mechanisms could explain the decrease in shoot Na concentrations in plants with pumpkin rootstocks: (i) Na exclusion by the pumpkin roots; and (ii) Na retention and accumulation within the pumpkin rootstock. Quantitative analysis indicated that the pumpkin roots excluded ∼74% of available Na, while there was nearly no Na exclusion by melon roots. Na retention by the pumpkin rootstocks decreased its amount in the shoot by an average 46.9% compared with uniform Na distribution throughout the plant. In contrast, no retention of Na could be found in plants grafted on melons.

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

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

    2015-12-01

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

  4. Arterial grafts balance survival between incomplete and complete revascularization: a series of 1000 consecutive coronary artery bypass graft patients with 98% arterial grafts.

    Kieser, Teresa M; Curran, Helen J; Rose, M Sarah; Norris, Colleen M; Graham, Michelle M

    2014-01-01

    Coronary artery bypass grafting (CABG) with incomplete revascularization (ICR) is thought to decrease survival. We studied the survival of patients with ICR undergoing total arterial grafting. In a consecutive series of all-comer 1000 patients with isolated CABG, operative and midterm survival were assessed for patients undergoing complete versus ICR, with odds ratios and hazard ratios, adjusted for European System for Cardiac Operative Risk Evaluation category, CABG urgency, age, and comorbidities. In this series of 1000 patients with 98% arterial grafts (2922 arterial, 59 vein grafts), 73% of patients with multivessel disease received bilateral internal mammary artery grafts. ICR occurred in 140 patients (14%). Operative mortality was 3.8% overall, 8.6% for patients with ICR, and 3.2% for patients with complete revascularization (P = .008). For operative mortality using multivariable logistic regression, after controlling for European System for Cardiac Operative Risk Evaluation category (P System for Cardiac Operative Risk Evaluation category (P reserved.

  5. Nature or Artifice? Grafting in Early Modern Surgery and Agronomy.

    Savoia, Paolo

    2017-01-01

    In 1597, Gaspare Tagliacozzi published a famous two-volume book on “plastic surgery.” The reconstructive technique he described was based on grafting skin taken from the arm onto the mutilated parts of the patient's damaged face – especially noses. This paper focuses on techniques of grafting, the “culture of grafting,” and the relationships between surgery and plant sciences in the sixteenth century. By describing the fascination with grafting in surgery, natural history, gardening, and agronomy the paper argues that grafting techniques were subject to delicate issues: to what extent it was morally acceptable to deceive the eye with artificial entities? and what was the status of the product of a surgical procedure that challenged the traditional natural/artificial distinction? Finally, this paper shows how in the seventeenth century grafting survived the crisis of Galenism by discussing the role it played in teratology and in controversies on the uses the new mechanistic anatomy.

  6. Evaluation of aortocoronary bypass graft patency by reconstructed CT image

    Kawakita, Seizaburo; Koide, Takashi; Saito, Yoshio; Yamamoto, Tadao; Iwasaki, Tadaaki

    1982-01-01

    Ten patients were examined in the period of three months from January to March 1981. The patients were operated from 1 month to 7 years before CT. A bypass to the left anterior descending artery (LAD) was grafted in 10 cases, 2 to the right coronary artery (RCA), 4 to an obtuse marginal artery (OM), and 1 to a diagonal artery. Image reconstruction was performed in 10 cases by using an image analytical computer Evaluskop. Appropriate planes for reconstruction were selected by trial and error methods upon observation of CT images. When gained picture of a graft course coincided with surgical records or angiography, the work of building images was concluded. On cross section, grafts to LAD were visualized in all 10 cases: 9 in the entire course and 1 in a proximal part of the graft. Two to RCA, 4 to OM and 1 to a diagonal were also successfully visualized. Reconstruction of graft images succeeded in 9 grafts of 6 cases. The course of a graft could be pursued from the proximal to the distal end adjacent to the cardiac chamber. The picture of a bypass to LAD was visualized in 6 of 10 grafts. Two bypass to RCA could be depicted, and 1 to OM was also found. However 3 to OM and 1 to a diagonal failed to be visualized throughout their courses in reconstructed images. I think that the causes of faillure mainly depended upon the course of the graft. When a graft was running arc-like surrounding the heart chamber, it was very difficult to depict its entire length in reconstructed images, though the graft could be detected in cross sections. These preliminary studies indicated that reconstruction of CT images had some benefits for the pursuit of graft courses. (J.P.N.)

  7. Fusion Rates of Different Anterior Grafts in Thoracolumbar Fractures.

    Antoni, Maxime; Charles, Yann Philippe; Walter, Axel; Schuller, Sébastien; Steib, Jean-Paul

    2015-11-01

    Retrospective CT analysis of anterior fusion in thoracolumbar trauma. The aim of this study was to compare fusion rates of different bone grafts and to analyze risk factors for pseudarthrosis. Interbody fusion is indicated in anterior column defects. Different grafts are used: autologous iliac crest, titanium mesh cages filled with cancellous bone, and autologous ribs. It is not clear which graft offers the most reliable fusion. Radiologic data of 116 patients (71 men, 45 women) operated for type A2, A3, B, or C fractures were analyzed. The average age was 44.6 years (range, 16-75 y) and follow-up was 2.7 years (range, 1-9 y). All patients were treated by posterior instrumentation followed by an anterior graft: 53 cases with iliac crest, 43 cases with mesh cages, and 20 with rib grafts. Fusion was evaluated on CT and classified into complete fusion, partial fusion, unipolar pseudarthrosis, and bipolar pseudarthrosis. Iliac crest fused in 66%, cages in 98%, and rib grafts in 90%. The fusion rate of cages filled with bone was significantly higher as the iliac graft fusion rate (P=0.002). The same was applied to rib grafts compared with iliac crest (P=0.041). Additional bone formation around the main graft, bridging both vertebral bodies, was observed in 31 of the 53 iliac crests grafts. Pseudarthrosis occurred more often in smokers (P=0.042). A relationship between fracture or instrumentation types, sex, age, BMI, and fusion could not be determined. Tricortical iliac crest grafts showed an unexpected high pseudarthrosis rate in thoracolumbar injuries. Their cortical bone is dense and their fusion surface is small. Rib grafts led to a better fusion when used in combination with the cancellous bone from the fractured vertebral body. Titanium mesh cages filled with cancellous bone led to the highest fusion rate and built a complete bony bridge between vertebral bodies. Smoking seemed to influence fusion. Case control study, Level III.

  8. The effect of carbon dioxide therapy on composite graft survival

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino Júnior, Ruy de Souza; Sousa, João Batista de

    2013-01-01

    PURPOSE: To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. METHODS: An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, h...

  9. Survey Study of Trunk Materials for Direct ATRP Grafting

    Saito, Tomonori [ORNL; Chatterjee, Sabornie [ORNL; Johnson, Joseph C. [ORNL; Dai, Sheng [ORNL; Brown, Suree [ORNL

    2015-02-01

    In previous study, we demonstrated a new method to prepare polymeric fiber adsorbents via a chemical-grafting method, namely atom-transfer radical polymerization (ATRP), and identified parameters affecting their uranium adsorption capacity. However, ATRP chemical grafting in the previous study still utilized conventional radiation-induced graft polymerization (RIGP) to introduce initiation sites on fibers. Therefore, the objective of the present study is to perform survey study of trunk fiber materials for direct ATRP chemical grafting method without RIGP for the preparation of fiber adsorbents for uranium recovery from seawater.

  10. Crystallization of calcium carbonate on radiation-grafted polyethylene films

    Hou Zhengchi; Zhang Fengying; Deng Bo; Yang Haijun; Chen Shuang; Sheng Kanglong

    2006-01-01

    In biomineralization processes, nucleation and growth of inorganic crystals can be regulated by organic template molecules. This has inspired great interest in studying mimic biomineralization. In our study, growing CaCO 3 crystals on PE films functionalized through radiation-induced grafting was attempted. PE films grafted with different functional groups of different distributions and densities were used as substrates for CaCO 3 nucleation and crystal growth from Ca(HCO 3 ) 2 supersaturated solution under different environmental conditions (e.g. additives and temperature) to study the effects and mechanisms. The grafted PE films were analyzed by ATR-FTIR and AFM, and the evolution of CaCO 3 crystal formation on the grafted PE film was characterized by SEM, FTIR, and XRD. The results indicated that heterogeneous nucleation of CaCO 3 crystals was significantly facilitated by the functional groups grafted on the surface of PE films, that the morphology of CaCO 3 crystals could be controlled by distribution and density of the grafted functional groups, and that polymorphism of CaCO 3 crystal could be regulated by selection of grafting functional groups. We believe that studying the effects of chemical structures on inorganic crystallization is of great importance since radiation-induced grafting is an effective method to graft desirable functional groups onto different polymers by selected monomers, in the endeavor of developing advanced organic/inorganic composites with high performance, with a wide availability of polymers, monomers and inorganic solutions. (authors)

  11. Biofabrication and testing of a fully cellular nerve graft

    Owens, Christopher M; Marga, Francoise; Forgacs, Gabor; Heesch, Cheryl M

    2013-01-01

    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. (paper)

  12. Radiation Grafted Polymer Membranes for Fuel Cell Applications

    Scherer, G.G.; Wallasch, F.; Ben Youcef, H.; Gubler, L.

    2012-01-01

    Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination α-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

  13. Cytocompatibility of amine functionalized carbon nanoparticles grafted on polyethylene

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

    2016-03-01

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

  14. Chrysanthemum cutting productivity and rooting ability are improved by grafting.

    Zhang, Jing; Chen, Sumei; Liu, Ruixia; Jiang, Jiafu; Chen, Fadi; Fang, Weimin

    2013-01-01

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

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

    Nelee Bisen

    2014-01-01

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

  16. Radiation Grafted Polymer Membranes for Fuel Cell Applications

    Scherer, G G; Wallasch, F; Ben Youcef, H; Gubler, L [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)

    2012-09-15

    Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination {alpha}-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

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

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

    2012-07-15

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

  18. [Fat grafting in facial burns sequelae].

    Viard, R; Bouguila, J; Voulliaume, D; Comparin, J-P; Dionyssopoulos, A; Foyatier, J-L

    2012-06-01

    Fat graft is now part of the armamentarium in face plastic surgery. It is successfully used in burn scars. The aim of our study is the discussion of the value of this technique in optimizing cosmetic result of burns face sequelae. Fifteen adult patients (10 females and five males) with scars resulting from severe burns 2 to 9 years previously were selected. The patients were treated by injection of adipose tissue harvested from abdominal subcutaneous fat and processed according to Coleman's technique. Two to three injections were administered at the dermohypodermal junction. Ages, sexes, aetiology of burn, facial burn sequelae, recipient sites, quantity of fat injected, aesthetic results are discussed. Patient age ranged from 21 to 55 years (average: 38). The mean follow-up of the study was 66 months (23-118). Patients received 7.5 (5-11) facial restorative surgeries before fat graft. Patients underwent two sessions of fat transfer, 33cc average per session. We did not report any complications. The clinical appearance, discussed by three surgeons and subjective patient feelings, after a 6-month follow-up period, suggests considerable improvement in the mimic features, skin texture, and thickness. The result is good in 86% of cases and acceptable in the other cases. Burns sequelae offer local conditions which justify special cannula can cross fibrosis and explaining the value of multiplying the sessions. Indications for lipostructure include four distinct nosological situations, sometimes combined. Lipostructure can restore a missing relief, filling a localized depression, reshape a lack of face volume or smooth a scarring skin. Fat graft seems to complete and improve the results of the standard surgical approach in burned face. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  19. Perfluorinated polymer grafting: influence of preirradiation conditions

    Moura, E.; Somessari, E.S.R.; Silveira, C.G.; Paes, H.A.; Sousa, C.A.; Fernandes, W.; Manzoli, J.E; Geraldo, A.B.; Cardozo, P.

    2009-01-01

    The technological interest of perfluorinated polymers is related to its specific properties like low chemical reactivity and high mechanical and temperature resistance. The development of polymeric membranes for PEM fuel cell dispositives requires beyond these characteristics, a long-life time performance and low cost compared to Nafion membranes. By these material have high crystallinity, the radiation grafting indeed occurs but this process generate a low mechanical resistance aggregate. In this way, it is necessary to render the polymer with a low crystallinity or even amorphous. Generally, irradiation under polymer melt temperatures makes the crystallinity breaking and polymer crosslinking. The main objective of this work was promoting the crosslinking process into perfluorinated polymers by pre-irradiation method and to precede styrene grafting by electron beam irradiation in a second step. The experimental methodology consists in pre-irradiate perfluorinated polymers films like PTFE and PFA under high temperature (> 300 deg C) and vacuum conditions by electron beam irradiation at 5 kGy to 30 kGy doses and 2,85 kGy/s to 22,4 kGy/s dose rates. To obtain temperatures above 300 deg C, it was necessary construct a vacuum chamber with a heating system where temperature process could be follow up in real time. Some molecular alterations in polymeric matrix were analyzed by Mid-ATR-FTIR spectroscopy; macroscopic changes are verified by gravimetry. The styrene grafting onto these samples is realized by electron beam irradiation at doses between 30 and 100 kGy. These results are discussed. (author)

  20. Intraoperative echocardiographic imaging of coronary arteries and graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass.

    Suematsu, Y; Takamoto, S; Ohtsuka, T

    2001-12-01

    No accepted approach exists for the intraoperative evaluation of the quality of coronary arteries and the technical adequacy of graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass. We assessed the accuracy of high-frequency epicardial echocardiography and power Doppler imaging in evaluating coronary arteries during coronary artery bypass grafting without cardiopulmonary bypass. To validate measurements of coronary arteries and graft anastomoses by high-frequency epicardial echocardiography and power Doppler imaging, we compared luminal diameters determined by these methods with diameters determined histologically in a study of off-pump coronary artery bypass grafting in 20 dogs. Technical errors were deliberately created in 10 grafts (stenosis group). The results of these animal validation studies showed that the maximum luminal diameters of coronary arteries and graft anastomoses measured by high-frequency epicardial echocardiography (HEE) and power Doppler imaging (PDI) correlated well with the histologic measurements: HEE = 1.027 x Histologic measurements + 0.005 (P anastomoses were examined intraoperatively by high-frequency epicardial echocardiography and power Doppler imaging, and luminal diameters determined by power Doppler imaging were compared with those determined by postoperative coronary angiography. The results demonstrated that graft anastomosis by power Doppler imaging correlated well with the angiographic measurements: PDI = 1.018 x Angiographic measurements - 0.106 (P anastomoses and can detect technical errors and inadequacies during coronary artery bypass grafting without cardiopulmonary bypass.

  1. Angiographic Evaluation of Carotid Artery Grafting with Prefabricated Small-Diameter, Small-Intestinal Submucosa Grafts in Sheep

    Pavcnik, Dusan; Obermiller, Josef; Uchida, Barry T.; Van Alstine, William; Edwards, James M.; Landry, Gregory J.; Kaufman, John A.; Keller, Frederick S.; Roesch, Josef

    2009-01-01

    The purpose of this study was to report the longitudinal angiographic evaluation of prefabricated lyophilized small-intestinal submucosa (SIS) grafts placed in ovine carotid arteries and to demonstrate a variety of complications that developed. A total of 24 grafts, 10 cm long and 6 mm in diameter, were placed surgically as interposition grafts. Graft patency at 1 week was evaluated by Doppler ultrasound, and angiography was used for follow-up at 1 month and at 3 to 4 months. A 90% patency rate was found at 1 week, 65% at 1 month, and 30% at 3 to 4 months. On the patent grafts, angiography demonstrated a variety of changes, such as anastomotic stenoses, graft diffuse dilations and dissections, and aneurysm formation. These findings have not been previously demonstrated angiographically by other investigators reporting results with small-diameter vessel grafts made from fresh small-intestinal submucosa (SIS). The complications found were partially related to the graft construction from four SIS layers. Detailed longitudinal angiographic study should become an essential part of any future evaluation of small-vessel SIS grafting.

  2. Bone scintigraphy in evaluating the viability of composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and free non-revascularized periosteal grafts

    Berggren, A.; Weiland, A.J.; Ostrup, L.T.

    1982-01-01

    Researchers studied the value of bone scintigraphy in the assessment of anastomotic patency and bone-cell viability in free bone grafts revascularized by microvascular anastomoses in twenty-seven dogs. The dogs were divided into three different groups, and scintigraphy was carried out using technetium-labeled methylene diphosphonate in composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and periosteal grafts placed in different recipient beds. The viability of the grafts were evaluated by histological examination and fluorescence microscopy after triple labeling with oxytetracycline on the first postoperative day, alizarin complexone on the fourth postoperative day, and DCAF on the eleventh postoperative day. A positive scintiscan within the first week following surgery indicated patent microvascular anastomoses, and histological study and fluorescence microscopy confirmed that bone throughout the graft was viable. A positive scintiscan one week after surgery or later does not necessarily indicate microvascular patency or bone-cell survival, because new bone formed by creeping substitution on the surface of a dead bone graft can result in this finding

  3. Improved patency and reduced intimal hyperplasia in PTFE grafts with luminal immobilized heparin compared with standard PTFE grafts at six months in a sheep model.

    Pedersen, G; Laxdal, E; Ellensen, V; Jonung, T; Mattsson, E

    2010-06-01

    The aim of this study was to compare the performance of polytetrafluoroethylene (PTFE) grafts with luminal coating of immobilized heparin to that of standard PTFE grafts at six months. Twenty-eight common carotid arteries in fourteen sheep were bypassed with heparin-coated PTFE grafts (6 mm diameter, 6 cm length) on one side and standard PTFE grafts on the other. The grafts were explanted after six months. The thickness of intimal hyperplasia (IH) in open grafts was measured with histomorphometrical methods. Two of 14 heparinized PTFE grafts and nine of 14 grafts in the control PTFE-group were occluded at explantation (P=0.006). Six-month patency rates for heparinized PTFE grafts and for standard PTFE grafts were 86% and 36%, respectively. Mean graft anastomotic IH thickness in open grafts were 0.074 mm for heparinized PTFE grafts and 0.259 mm for PTFE-grafts (P=0.006). PTFE grafts with luminal coating containing immobilized heparin had significantly better patency and recruited less intimal hyperplasia than standard PTFE grafts at six months.

  4. Diaphragms obtained by radiochemical grafting in PTFE

    Nenner, T.; Fahrasmane, A.

    1984-01-01

    Diaphragms for alkaline water electrolysis are prepared by radiochemical grafting of PTFE fabric with styrene, which is later on sulfonated, or with acrylic acid. The diaphragms obtained are mechanically resistant to potash at temperatures up to 200 0 C, but show some degrafting, which limits the lifetime. The sulfonated styrene group has been found to be more stable in electrolysis than the acrylic acid. In both cases, the incorporation of a cross-linking agent like divinyl benzene improves the lifetime of the diaphragms. Electrolysis during 500 hours at 120 0 C and 10 kAm 2 could be performed. (author)

  5. Grafting of Porous Polymers for Biological Applications

    Smolko, E. E. [Comisión Nacional de Energía Atómica, Buenos Aires (Argentina); Grasselli, M. [Dpto. LaMaBio, Dpto. de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires (Argentina)

    2009-07-01

    Research on application of radiation processing to polymers is mainly focused by the National Atomic Commission (CNEA). The Agricultural and Industrial Applications Laboratory Unit operates at the Ezeiza Atomic Center since the end of 1980s. Since 1997 a new research group headed by Dr. O. Cascone and Dr. M. Grasselli, devoted to downstream processing of proteins from the University of Buenos Aires, was involved in the implementation of grafting techniques in collaboration with Dr. E. Smolko from CNEA. In 1999 Dr. M. Grasselli moved to the Universidad Nacional de Quilmes where he continued working on application of gamma radiation to materials for biotechnological process. (author)

  6. Grafting of Porous Polymers for Biological Applications

    Smolko, E.E.; Grasselli, M.

    2009-01-01

    Research on application of radiation processing to polymers is mainly focused by the National Atomic Commission (CNEA). The Agricultural and Industrial Applications Laboratory Unit operates at the Ezeiza Atomic Center since the end of 1980s. Since 1997 a new research group headed by Dr. O. Cascone and Dr. M. Grasselli, devoted to downstream processing of proteins from the University of Buenos Aires, was involved in the implementation of grafting techniques in collaboration with Dr. E. Smolko from CNEA. In 1999 Dr. M. Grasselli moved to the Universidad Nacional de Quilmes where he continued working on application of gamma radiation to materials for biotechnological process. (author)

  7. Late graft explants in endovascular aneurysm repair.

    Turney, Eric J; Steenberge, Sean P; Lyden, Sean P; Eagleton, Matthew J; Srivastava, Sunita D; Sarac, Timur P; Kelso, Rebecca L; Clair, Daniel G

    2014-04-01

    With more than a decade of use of endovascular aneurysm repair (EVAR), we expect to see a rise in the number of failing endografts. We review a single-center experience with EVAR explants to identify patterns of presentation and understand operative outcomes that may alter clinical management. A retrospective analysis of EVARs requiring late explants, >1 month after implant, was performed. Patient demographics, type of graft, duration of implant, reason for removal, operative technique, length of stay, complications, and in-hospital and late mortality were reviewed. During 1999 to 2012, 100 patients (91% men) required EVAR explant, of which 61 were placed at another institution. The average age was 75 years (range, 50-93 years). The median length of time since implantation was 41 months (range, 1-144 months). Explanted grafts included 25 AneuRx (Medtronic, Minneapolis, Minn), 25 Excluder (W. L. Gore & Associates, Flagstaff, Ariz), 17 Zenith (Cook Medical, Bloomington, Ind), 15 Talent (Medtronic), 10 Ancure (Guidant, Indianapolis, Ind), 4 Powerlink (Endologix, Irvine, Calif), 1 Endurant (Medtronic), 1 Quantum LP (Cordis, Miami Lakes, Fla), 1 Aorta Uni Iliac Rupture Graft (Cook Medical, Bloomington, Ind), and 1 homemade tube graft. Overall 30-day mortality was 17%, with an elective case mortality of 9.9%, nonelective case mortality of 37%, and 56% mortality for ruptures. Endoleak was the most common indication for explant, with one or more endoleaks present in 82% (type I, 40%; II, 30%; III, 22%; endotension, 6%; multiple, 16%). Other reasons for explant included infection (13%), acute thrombosis (4%), and claudication (1%). In the first 12 months, 23 patients required explants, with type I endoleak (48%) and infection (35%) the most frequent indication. Conversely, 22 patients required explants after 5 years, with type I (36%) and type III (32%) endoleak responsible for most indications. The rate of EVAR late explants has increased during the past decade at our

  8. [Immunological mechanisms of graft versus tumor effect].

    Ine, Shoji; Yamada, Minami; Miyamura, Koichi; Sasaki, Takeshi

    2003-09-01

    Lesson from hematopoietic stem cell transplantation demonstrated that donor immuno-surveillance system can eradicate tumor cells. This is so-call graft versus tumor(GVT) effect. Antigen presenting cells show peptide from minor antigen rather leukemic specific antigen in the context of major histocompatibility complex. The effector cells composed of CD8 T lymphocyte, CD4 T lymphocyte, natural killer cell and natural killer T cell. Death signal was transmitted from effector cells via granzyme/perforin system and FasL/Fas system, and recently TRAIL system seems most important for GVT effect.

  9. Reshaping Human Antibodies: Grafting an Antilysozyme Activity

    Verhoeyen, Martine; Milstein, Cesar; Winter, Greg

    1988-03-01

    The production of therapeutic human monoclonal antibodies by hybridoma technology has proved difficult, and this has prompted the ``humanizing'' of mouse monoclonal antibodies by recombinant DNA techniques. It was shown previously that the binding site for a small hapten could be grafted from the heavy-chain variable domain of a mouse antibody to that of a human myeloma protein by transplanting the hypervariable loops. It is now shown that a large binding site for a protein antigen (lysozyme) can also be transplanted from mouse to human heavy chain. The success of such constructions may be facilitated by an induced-fit mechanism.

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

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

    1992-12-01

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

  11. Characteristics of elongated and ruptured anterior cruciate ligament grafts: An analysis of 21 consecutive revision cases

    Kohei Iio

    2017-04-01

    Conclusion: The location of the original femoral tunnel was more proximal in patients with elongated grafts than in those with ruptured grafts. Different bone tunnel position from native ACL might lead to graft elongation.

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

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

    2007-10-15

    Mutual radiation grafting technique has been applied to carry out grafting of acrylamide (AAm) onto guar gum (GG) using high-energy Co{sup 60} {gamma} radiation to enhance its flocculating properties for industrial effluents. The grafted product was characterized using analytical probes like elemental analysis, thermal analysis, Fourier transformed infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The grafting extent was observed to decrease with the dose rate and increase with the concentration of AAm. Thermo gravimetric analysis (TGA) of grafted and ungrafted samples indicated better stability of grafted product. {gamma} and microwave radiation effect on grafted and virgin GG has also been reported.

  13. Effect of centrifugation and washing on adipose graft viability: a new method to improve graft efficiency.

    Hoareau, Laurence; Bencharif, Karima; Girard, Anne-Claire; Gence, Lydie; Delarue, Pierre; Hulard, Olivier; Festy, Franck; Roche, Regis

    2013-05-01

    Adipose tissue grafting is a promising method in the field of surgical filling. We studied the effect of centrifugation on fat grafts, and we propose an optimised protocol for the improvement of adipose tissue viability. Adipose tissue was subjected to different centrifugations, and the volumes of interstitial liquid and oil released were measured to choose the optimal condition. Tissue from this condition was then compared to tissue obtained from two traditional techniques: strong centrifugation (commonly 3 min at 3000 rpm/900 g), and decantation, by injecting into immunodeficient mice. The cytokine interleukin-6 (IL-6) and chemokine monocyte chemotactic protein-1 (MCP-1) were assayed 24 h post-injection, and after 1 month of grafting the state of the lipografts was evaluated through macroscopic and histological analysis, with oil gap area measurement. Strong centrifugation (900 g, 1800 g) is deleterious for adipose tissue because it leads to until threefold more adipocyte death compared to low centrifugation (100 g, 400 g). In addition, mice injected with strong centrifuged and non-centrifuged adipose tissue have higher rates of blood IL-6 and MCP-1, compared to those grafted with soft centrifuged fat. Moreover, extensive lipid vacuoles were detectable on histological sections of the non-centrifuged lipografts, whereas lipografts from soft centrifugation contain a higher amount of connective tissue containing collagen fibres. It is necessary to wash and centrifuge adipose tissue before reinjection in order to remove infiltration liquid and associated toxic molecules, which in the long term are deleterious for the graft. However, strong centrifugation is not recommended since it leads very quickly to greater adipocyte death. Thus, soft centrifugation (400 g/1 min), preceded by washings, seems to be the most appropriate protocol for the reinjection of adipose tissue. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published

  14. Laparoscopic jejunoileal side-to-side anastomosis for the treatment of type 2 diabetes mellitus in Chinese patients with a body mass index of 24–32 kg/m2

    Jin Li

    2016-01-01

    Conclusion: LJISSA seems to be a promising procedure for the control of T2DM. A multicenter study with a larger number of patients and a longer follow-up period is needed to substantiate our preliminary findings.

  15. Effect of grafted oligopeptides on friction.

    Iarikov, Dmitri D; Ducker, William A

    2013-05-14

    Frictional and normal forces in aqueous solution at 25 °C were measured between a glass particle and oligopeptide films grafted from a glass plate. Homopeptide molecules consisting of 11 monomers of either glutamine, leucine, glutamic acid, lysine, or phenylalanine and one heteropolymer were each "grafted from" an oxidized silicon wafer using microwave-assisted solid-phase peptide synthesis. The peptide films were characterized using X-ray photoelectron spectroscopy and secondary ion mass spectrometry. Frictional force measurements showed that the oligopeptides increased the magnitude of friction compared to that on a bare hydrophilic silicon wafer but that the friction was a strong function of the nature of the monomer unit. Overall we find that the friction is lower for more hydrophilic films. For example, the most hydrophobic monomer, leucine, exhibited the highest friction whereas the hydrophilic monomer, polyglutamic acid, exhibited the lowest friction at zero load. When the two surfaces had opposite charges, there was a strong attraction, adhesion, and high friction between the surfaces. Friction for all polymers was lower in phosphate-buffered saline than in pure water, which was attributed to lubrication via hydrated salt ions.

  16. Grafting cavitands on the Si(100) surface.

    Condorelli, Guglielmo G; Motta, Alessandro; Favazza, Maria; Fragalà, Ignazio L; Busi, Marco; Menozzi, Edoardo; Dalcanale, Enrico; Cristofolini, Luigi

    2006-12-19

    Cavitand molecules having double bond terminated alkyl chains and different bridging groups at the upper rim have been grafted on H-terminated Si(100) surface via photochemical hydrosilylation of the double bonds. Pure and mixed monolayers have been obtained from mesitylene solutions of either pure cavitand or cavitand/1-octene mixtures. Angle resolved high-resolution X-ray photoelectron spectroscopy has been used as the main tool for the monolayer characterization. The cavitand decorated surface consists of Si-C bonded layers with the upper rim at the top of the layer. Grafting of pure cavitands leads to not-well-packed layers, which are not able to efficiently passivate the Si(100) surface. By contrast, monolayers obtained from cavitand/1-octene mixtures consist of well-packed layers since they prevent silicon oxidation after aging. AFM measurements showed that these monolayers have a structured topography, with objects protruding from the Si(100) surface with average heights compatible with the expected ones for cavitand molecules.

  17. Pediatric burn wound impetigo after grafting.

    Aikins, Kimberly; Prasad, Narayan; Menon, Seema; Harvey, John G; Holland, Andrew J A

    2015-01-01

    Modern burn care techniques have reduced the risk of infection of the acute burn wound, resulting in more rapid healing and a lower incidence of graft loss. Secondary breakdown may still occur. The loss of epithelium in association with multifocal superficial abscesses and ulceration has been termed burns impetigo. This may result in considerable morbidity and require prolonged treatment. The events preceding development, the impact on the patient, and the ideal treatment appear unclear and poorly reported. In 5 years, between 2006 and 2011, 406 pediatric burns were treated with skin grafts, with 7% developing burns impetigo. Time to resolution ranged from 5 to 241 days: the mean time to complete healing was greatest with conservative management (96 days), followed by antibacterial dressings (37 days), oral antibiotics (36 days), topical steroids (16 days), and oral antibiotics in combination with topical steroids (13.5 days). Burns impetigo resulted in significant morbidity, requiring multiple visits to the treatment center and prolonged symptoms. Delay in diagnosis and treatment resulted in worse outcomes. Prompt consideration of burns impetigo should occur when postgraft patients present with suggestive clinical signs and treatment with oral antibiotics plus topical steroids should be considered.

  18. Application of grafted polynomial function in forecasting cotton ...

    A study was conducted to forecast cotton production trend with the application of a grafted polynomial function in Nigeria from 1985 through 2013. Grafted models are used in econometrics to embark on economic analysis involving time series. In economic time series, the paucity of data and their availability has always ...

  19. Functionalization of poly (4-vinylpyrrolidone) through γ - radiation induced grafting

    Pande, C.S.; Ambasta, A.K.; Kumari, Mamta; Sharma, Ajay

    2002-01-01

    Cross-linked poly(N-vinylpyrrolidone) and N-vinylimidazole were mutually irradiated in water under nitrogen with γ-radiations. A detailed study of grafting was made under various reaction parameters. The results have been compared with the grafting done in air. (author)

  20. The Graft Copolymerisation of Acrylamide onto Cellulose using ...

    DR. MIKE HORSFALL

    ABSTRACT: Graft copolymers of acrylamide onto holocellulose derived from cocoa. (Theobroma cacao) wood meal have been produced using hydroquinone enhanced Fe2+/H2O2 redox system. The addition of hydroquinone to the redox system affected the effectiveness of the redox system to initiate graft copolymer ...

  1. Hemolytic anemia caused by kinking of dacron grafts implanted in ...

    Background: Hemolytic anemia caused by a kinked Dacron graft is a rare complication after repair of acute aortic dissection. We present a case of hemolytic anemia due to kinking of previously implanted Dacron graft for ascending aorta dissection treated by surgery and replaced with new Dacron. Case Details: We report a ...

  2. Rapid synthesis of graft copolymers from natural cellulose fibers.

    Thakur, Vijay Kumar; Thakur, Manju Kumari; Gupta, Raju Kumar

    2013-10-15

    Cellulose is the most abundant natural polysaccharide polymer, which is used as such or its derivatives in a number of advanced applications, such as in paper, packaging, biosorption, and biomedical. In present communication, in an effort to develop a proficient way to rapidly synthesize poly(methyl acrylate)-graft-cellulose (PMA-g-cellulose) copolymers, rapid graft copolymerization synthesis was carried out under microwave conditions using ferrous ammonium sulfate-potassium per sulfate (FAS-KPS) as redox initiator. Different reaction parameters such as microwave radiation power, ratio of monomer, solvent and initiator concentrations were optimized to get the highest percentage of grafting. Grafting percentage was found to increase with increase in microwave power up to 70%, and maximum 36.73% grafting was obtained after optimization of all parameters. Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA/DTA/DTG) analysis were used to confirm the graft copolymerization of poly(methyl acrylate) (PMA) onto the mercerized cellulose. The grafted cellulosic polymers were subsequently subjected to the evaluation of different physico-chemical properties in order to access their application in everyday life, in a direction toward green environment. The grafted copolymers demonstrated increased chemical resistance, and higher thermal stability. Published by Elsevier Ltd.

  3. Solvent influence during radiation induced grafting of styrene in PVDF

    Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.

    2013-01-01

    Radiation-induced grafting was studied to produce styrene grafted poly(vinylidene fluoride) (PVDF) membranes. PVDF films with 0.125 mm thickness were irradiated at doses between 5 and 20 kGy in the presence of styrene/N,N-dimethylformamide (DMF), styrene/acetone or styrene/toluene solutions (1:1, v/v) at dose rate of 5 kGy h -1 by simultaneous method, using gamma rays from a Co-60, under nitrogen atmosphere and at room temperature. The films were characterized before and after modification by grafting yield (GY %), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM and EDS), differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). GY results shows that grafting increases with dose and toluene hinders the grafting, leading to a small GY comparing to DMF and acetone. It was possible to confirm the grafting of styrene by FT-IR due to the new characteristics peaks and by the TG and DSC due to changes in thermal behavior of the grafted material. SEM and EDS show surface and cross-section distribution of the grafting, which takes place on the surface and heterogeneously with toluene as solvent and homogeneously and penetrating into the inner layers of the matrix using DMF and acetone as solvent. (author)

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

    Klasen, Hendrik Jan

    1981-01-01

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

  5. Maleic anhydride grafting on EPDM rubber in the melt

    Oostenbrink, A.J.; Oostenbrink, A.J.; Gaymans, R.J.

    1992-01-01

    The grafting of maleic anhydride on a EPDM rubber was studied with a twin screw extruder. The effect of barrel temperatures, throughput, maleic anhydride concentration and peroxide concentration [bis(t-butyl peroxy isopropyl)benzene] on the degree of grafting and melt viscosity was studied. The

  6. Resorbable screws for fixation of autologous bone grafts

    Raghoebar, GM; Liem, RSB; Bos, RRM; van der Wal, JE; Vissink, A

    The aim of this study was to evaluate the suitability of resorbable screws made of poly (D,L-lactide) acid (PDLLA) for fixation of autologous bone grafts related to graft regeneration and osseointegration of dental implants. In eight edentulous patients suffering from insufficient retention of their

  7. [Skin graft, smoking and diabetes mellitus type 2].

    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.

  8. Effectiveness of Fibrin Glue in Adherence of Skin Graft.

    Reddy, Konda Sireesha; Chittoria, Ravi Kumar; Babu, Preethitha; Marimuthu, Senthil Kumaran; Kumar, Sudhanva Hemanth; Subbarayan, Elan Kumar; Chavan, Vinayak; Mohapatra, Devi Prasad; Sivakumar, Dinesh Kumar; Friji, M T

    2017-01-01

    Graft fixation is important for graft take. Fibrin glue has been proposed as an ideal material, because of its human origin and it provides firm adhesion in seconds or minutes. To evaluate the efficiency of fibrin glue, in increasing the take of skin graft. Assessment includes surgical time taken for graft fixation, haematoma/seroma formation, engraftment and wound closure by day 14. The study is an observational prospective study conducted in the Department of Plastic Surgery, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, from January 2016 to June 2016. Sixteen patients who underwent split skin grafting were assessed during the study period. Fibrin glue was used on the recipient bed before grafting. Better haemostasis and graft adhesion, with a significant reduction of surgical time, were noted. The safety profile of fibrin glue was excellent as indicated by the lack of any related serious adverse experiences. These findings demonstrate that it is safe and effective for attachment of skin grafts, with outcomes at least as good as conventional methods.

  9. Forcasting Acha production in Nigeria: A comparison of grafted ...

    A grafted model (Quadratic-Quadratic-Linear) was estimated to forecast Acha output for periods outside the sample. The estimated structural parameters gave an R squared values of 0.81 and 0.99 for the linear and grafted respectively. Forecast were generated to evaluate the predictive performance of the estimated models ...

  10. Nipple-areolar complex (nac) composite grafts in the Management ...

    composite” graft. This is because the skin of the areola and especially the nipple are usually thicker than the case is in the usual full-thickness skin grafts (FTSG). In traditional breast reductions, the nipple-areolar complex is located to its new position ...

  11. Characterization of Functionalized Acrylic acid /4- Vinyl Pyridine Graft Copolymers

    Kamal, H.; Mahmoud, Gh.A.; Hegazy, D.E.

    2009-01-01

    Properties and characterization of the membranes prepared by radiation grafting of acrylic acid (AAc) or/ and 4-vinyl pyridine (4VP) onto low density polyethylene (LDPE) and polypropylene (PP) films were carried out. The FTIR spectra for the grafted membranes were studied to evaluate the structure change as a result of grafting. The swelling behaviour of the graft copolymer in methanol was studied. It was found that the grafting of AAc and/ or 4- VP onto LDPE and PP resulted in introducing good hydrophilic properties to such polymer substrates. The hydrophilic properties were directly proportional to the amount of functional groups. The mechanical properties (Young's modulus, elongation percent and tensile strength) of the grafted membranes also, have been investigated. As the grafting degree increases, the modulus also increases. Increasing the hydrophilicity of the membranes by chemical treatment enhances its mechanical properties. The thermal parameters of the grafted membranes such as δH m1 . δH m2 , and T rc have been also studied by using DSC

  12. Stent Graft in Managing Juxta-Renal Aortoiliac Occlusion

    Prabhudesai, V.; Mitra, K.; West, D. J.; Dean, M. R. E.

    2003-01-01

    Endovascular procedures are frequently used as an alternative to surgical bypass in aortic and iliac occlusion. Stents have revolutionized the scope of such endovascular procedures, but there are few reports of stents or stent grafts in occlusive juxta-renal aortic occlusion. We present a case where such occlusion was managed by use of a stent graft with successful outcome

  13. 21 CFR 872.3930 - Bone grafting material.

    2010-04-01

    ... of the oral and maxillofacial region. (b) Classification. (1) Class II (special controls) for bone grafting materials that do not contain a drug that is a therapeutic biologic. The special control is FDA's “Class II Special Controls Guidance Document: Dental Bone Grafting Material Devices.” (See § 872.1(e) for...

  14. Grafted Cellulose Based Adsorbents for Selective Separation Purposes

    Takacs, E; Wojnarovits, L [Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary)

    2012-09-15

    The effect of high energy ionizing radiation on cotton-cellulose was studied. It was found that degradation of cellulose started at low doses, below 5 kGy, resulting in decrease in the degree of polymerization. However, the mechanical properties of cotton-cellulose samples only slightly changed with the dose up to 40 kGy. Acrylate type monomers were successfully grafted to cellulose by mutual and by pre-irradiation grafting technique. With both techniques the grafting yield increased with increasing dose and monomer concentration. In the case of pre-irradiation grafting the increase in grafting time also resulted in an increase in grafting percentage. Cotton-cellulose was functionalized using pre-irradiation grafting (PIG) and simultaneous grafting (SG) of glycidyl methacrylate (GMA). The adsorption properties of this material were further enhanced by {beta}-cyclodextrin (CD) immobilization. This molecule is known for its unique ability to form inclusion complexes among others with aromatic compounds like phenols, pesticide, dyes, etc. (author)

  15. Graft Copolymerization Of Methyl Methacrylate Onto Agave Cellulose

    Noor Afizah Rosli; Ishak Ahmad; Ibrahim Abdullah; Farah Hannan Anuar

    2014-01-01

    The grafting polymerization of methyl methacrylate (MMA) and Agave cellulose was prepared and the grafting reaction conditions were optimized by varying the reaction time and temperature, and ratio of monomer to cellulose. The resulting graft copolymers were characterized by Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy (SEM). The experimental results showed that the optimal conditions were at a temperature of 45 degree Celsius for 90 min with ratio monomer to cellulose at 1:1 (g/ g). An additional peak at 1738 cm -1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted cellulose, respectively. Grafting of MMA onto cellulose enhanced its thermal stability and SEM observation further furnished evidence of grafting MMA onto Agave cellulose with increasing cellulose diameter and surface roughness. (author)

  16. Solvent influence during radiation induced grafting of styrene in PVDF

    Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B., E-mail: hp.ferreira@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Radiation-induced grafting was studied to produce styrene grafted poly(vinylidene fluoride) (PVDF) membranes. PVDF films with 0.125 mm thickness were irradiated at doses between 5 and 20 kGy in the presence of styrene/N,N-dimethylformamide (DMF), styrene/acetone or styrene/toluene solutions (1:1, v/v) at dose rate of 5 kGy h{sup -1} by simultaneous method, using gamma rays from a Co-60, under nitrogen atmosphere and at room temperature. The films were characterized before and after modification by grafting yield (GY %), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM and EDS), differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). GY results shows that grafting increases with dose and toluene hinders the grafting, leading to a small GY comparing to DMF and acetone. It was possible to confirm the grafting of styrene by FT-IR due to the new characteristics peaks and by the TG and DSC due to changes in thermal behavior of the grafted material. SEM and EDS show surface and cross-section distribution of the grafting, which takes place on the surface and heterogeneously with toluene as solvent and homogeneously and penetrating into the inner layers of the matrix using DMF and acetone as solvent. (author)

  17. Vascularized fibular graft combined with vacuum assisted closure in ...

    The flowthrough fibular graft combined with Vacuum Assisted Closure (VAC) controlled the infection, shortened the course of treatment, and effectively restored limb function when applied to the treatment of tibial defects. Keywords: Tibial defect, Flow-through fibular graft, Vacuum Assisted Closure, Chronic Osteomyelitis ...

  18. Radiation chemical grafting of vinyl acetate and styrene on nitrocellulose

    Chapiro, A.; Foex, M.; Jendrychowska-Bonamour, A.M.

    1977-01-01

    Vinyl acetate and styrene were grafted onto nitrocellulose using the direct radiation grafting technique with 500 and 3000 Ci 60 Co γ sources. For vinyl acetate, the reaction proceeds homogeneously. The kinetics are dominated by degradative chain transfer to the nitrocellulose. The polymerization of vinyl acetate was examined in the presence of isoamyl nitrate, a model for nitrocellulose; the transfer constant was determined and the results are treated semi-quantitatively. For styrene, grafting occurs in a swollen film irradiated in the presence of excess monomer. The diffusion of styrene into nitrocellulose is extremely slow; methanol was added to the reaction mixture to favour diffusion which was found to obey Fick's law. The diffusion constant and activation energy of diffusion are evaluated. The grafting kinetics are controlled by monomer diffusion, accounting for the increase of dose-rate exponent with temperature. A spontaneous grafting process occurs in the absence of irradiation. It is initiated by macroradicals arising from thermal decomposition of nitrocellulose. (author)

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

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

    2015-04-15

    Composite vascular grafts formed by micro-imprinting and electrospinning exhibited improved mechanical properties relative to those formed by electrospinning alone. The three-layered composite grafts mimic the three-layered structure of natural blood vessels. The middle layer is made by micro-imprinting poly-p-dioxanone (PPDO), while the inner and outer layers are electrospun mixtures of chitosan and polyvinyl alcohol. The graft morphology is characterized with scanning electron microscopy. For constant graft thicknesses, the PPDO increases the mechanical strength. Cells cultivated on the vascular grafts adhere and proliferate better because of the natural, biological chitosan in the inner and outer layers. Overall, the composite scaffolds could be good candidates for blood vessel repair.

  20. Study on radiation grafting reaction of MMA onto hydroxyapatite

    Jiang Bo

    1996-01-01

    The grafting reaction of MMA onto hydroxyapatite has been studied with the pre-irradiation method in air. The effects of radiation dose, monomer concentration, reaction temperature and inorganic acid on the system are observed. The grafting copolymerization is found to be controlled by the kinetics. If proper kinetic conditions are selected, a better grafting yield can be obtained. Employing weight method, burning method as well as SeM and IR analysis, it has been proved that MMA is definitely grafted onto hydroxyapatite by chemical bonds, which shows that it is possible to improve the interface of inorganic-organic composite materials and to make bioactive ceramics by using radiation induced-grafting copolymerization

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

    Rubens Eduardo Gigli

    2008-01-01

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

  2. Albumin grafting on polymer surfaces by gamma-irradiation

    Kamath, K.R.; Park, K.; DeMeo, D.

    1993-01-01

    Polymeric biomaterial surfaces were modified by albumin grafting to improve their blood compatibility. Albumin molecules were functionalized by introduction of double bonds. The functionalized albumin was covalently attached to polypropylene fibers, polycarbonate, and poly(vinyl chloride) by gamma-irradiation. ESCA and ATR/FTIR analysis of the control and grafted surfaces was conducted. Albumin grafting efficiency was found to be dependent on the gamma-irradiation time and the concentration of albumin as indicated by platelet adhesion studies. The grafted albumin molecules were not displaced when exposed to blood for prolonged time period. Finally, PLEXUS oxygenators grafted with albumin using this approach showed a significant reduction in platelet adhesion when compared to control

  3. Grafting improves cucumber water stress tolerance in Saudi Arabia

    Abdulaziz R. Al-Harbi

    2018-02-01

    Full Text Available Water scarcity is a major limiting factor for crop productivity in arid and semi-arid areas. Grafting elite commercial cultivars onto selected vigorous rootstocks is considered as a useful strategy to alleviate the impact of environmental stresses. This study aims to investigate the feasibility of using grafting to improve fruit yield and quality of cucumber under water stress conditions. Alosama F1 cucumber cultivar (Cucumis sativus L. was grafted onto Affyne (Cucumis sativus L. and Shintoza A90 (Cucurbitamaxima × C. moschata rootstocks. Non-grafted plants were used as control. All genotypes were grown under three surface drip irrigation regimes: 50%, 75% and 100% of the crop evapotranspiration (ETc, which represent high-water stress, moderate-water stress and non-water stress conditions, respectively. Yield and fruit quality traits were analyzed and assessed. In comparison to the non-grafted plants, the best grafting treatment under water stress was Alosama F1 grafted onto Shintoza A90 rootstock. It had an overall improved yield and fruit quality under water stress owing to an increase in the total fruit yield by 27%, from 4.815 kg plant−1 in non-grafted treatment to 6.149 kg plant−1 in grafted treatment under moderate -water stress, total soluble solid contents (13%, titratable acidity (39% and vitamin C (33%. The soil water contents were low in soil surface and increase gradually with soil depth, while salt distribution showed an adverse trend. The positive effects of grafting on plant growth, productivity, and water use efficiency support this strategy as an useful tool for improving water stress tolerance in greenhouse grown cucumber in Saudi Arabia.

  4. Bacterial adherence to vascular grafts after in vitro bacteremia

    Rosenman, J.E.; Pearce, W.H.; Kempczinski, R.F.

    1985-01-01

    All currently used arterial prosthetics have a greater susceptibility to infection following bacteremia than does autogenous tissue. This experiment compares quantitative bacterial adherence to various prosthetic materials after bacteremia carried out in a tightly controlled and quantitative fashion. Ten centimeters long, 4 mm i.d. Dacron, umbilical vein (HUV), and polytetrafluoroethylene (PTFE) grafts, as well as PTFE grafts with a running suture line at the midportion were tested. Each graft was interposed into a pulsatile perfusion system modified from a Waters MOX 100 TM renal transplant pump. Indium-111-labeled Staphylococcus aureus were added to heparinized canine blood to give a mean concentration of 4.7 X 10(6) bacteria/cc. This infected blood was recirculated through each graft for 30 min at a rate of 125 cc/m, 100 Torr (sys), 60 beats/min. The gamma counts/graft were used to calculate the number of bacteria/cm2 of graft surface. After nine experiments, a mean of 9.63 X 10(5) bacteria/cm2 were adherent to the Dacron, 1.04 X 10(5) bacteria/cm2 to the HUV, and 2.15 X 10(4) bacteria/cm2 to the PTFE. These differences were all significant at the 0.05 level. The addition of a suture line increased bacterial adherence to the PTFE graft by 50%. These results suggest that PTFE is the vascular graft material of choice when a prosthetic graft must be implanted despite a high risk of subsequent clinical bacteremia. An in vitro, pulsatile perfusion model gave accurate and reproducible results, and appears well suited for further studies of bacterial, or platelet adherence to grafts, as well as the biomechanics of vascular conduits

  5. Grafting improves cucumber water stress tolerance in Saudi Arabia.

    Al-Harbi, Abdulaziz R; Al-Omran, Abdulrasoul M; Alharbi, Khadiga

    2018-02-01

    Water scarcity is a major limiting factor for crop productivity in arid and semi-arid areas. Grafting elite commercial cultivars onto selected vigorous rootstocks is considered as a useful strategy to alleviate the impact of environmental stresses. This study aims to investigate the feasibility of using grafting to improve fruit yield and quality of cucumber under water stress conditions. Alosama F 1 cucumber cultivar ( Cucumis sativus L.) was grafted onto Affyne ( Cucumis sativus L.) and Shintoza A90 ( Cucurbitamaxima × C. moschata ) rootstocks. Non-grafted plants were used as control. All genotypes were grown under three surface drip irrigation regimes: 50%, 75% and 100% of the crop evapotranspiration (ETc), which represent high-water stress, moderate-water stress and non-water stress conditions, respectively. Yield and fruit quality traits were analyzed and assessed. In comparison to the non-grafted plants, the best grafting treatment under water stress was Alosama F 1 grafted onto Shintoza A90 rootstock. It had an overall improved yield and fruit quality under water stress owing to an increase in the total fruit yield by 27%, from 4.815 kg plant -1 in non-grafted treatment to 6.149 kg plant -1 in grafted treatment under moderate -water stress, total soluble solid contents (13%), titratable acidity (39%) and vitamin C (33%). The soil water contents were low in soil surface and increase gradually with soil depth, while salt distribution showed an adverse trend. The positive effects of grafting on plant growth, productivity, and water use efficiency support this strategy as an useful tool for improving water stress tolerance in greenhouse grown cucumber in Saudi Arabia.

  6. Grafting: a technique to modify ion accumulation in horticultural crops

    Muhammad Azher Nawaz

    2016-10-01

    Full Text Available Grafting is a centuries-old technique used in plants to obtain economic benefits. Grafting increases nutrient uptake and utilization efficiency in a number of plant species, including fruits, vegetables, and ornamentals. Selected rootstocks of the same species or close relatives are utilized in grafting. Rootstocks absorb more water and ions than self-rooted plants and transport these water and ions to the aboveground scion. Ion uptake is regulated by a complex communication mechanism between the scion and rootstock. Sugars, hormones, and miRNAs function as long-distance signaling molecules and regulate ion uptake and ion homeostasis by affecting the activity of ion transporters. This review summarizes available information on the effect of rootstock on nutrient uptake and utilization and the mechanisms involved. Information on specific nutrient-efficient rootstocks for different crops of commercial importance is also provided. Several other important approaches, such as interstocking (during double grafting, inarching, use of plant-growth-promoting rhizobacteria, use of arbuscular mycorrhizal fungi, use of plant growth substances (e.g., auxin and melatonin, and use of genetically engineered rootstocks and scions (transgrafting, are highlighted; these approaches can be combined with grafting to enhance nutrient uptake and utilization in commercially important plant species. Whether the rootstock and scion affect each other’s soil microbiota and their effect on the nutrient absorption of rootstocks remain largely unknown. Similarly, the physiological and molecular bases of grafting, crease formation, and incompatibility are not fully identified and require investigation. Grafting in horticultural crops can help reveal the basic biology of grafting, the reasons for incompatibility, sensing, and signaling of nutrients, ion uptake and transport, and the mechanism of heavy metal accumulation and restriction in rootstocks. Ion transporter and mi

  7. Determination of grafting conversion degree in PS/PS-graft-POSS/POSS hybrid nanocomposites obtained through reactive processing

    Bianchi, Otavio; Repenning, Gustavo B.; Mauler, Raquel S.; Oliveira, Ricardo V.B.; Canto, Leonardo B.

    2011-01-01

    Hybrid nanocomposites of polystyrene (PS) and polyhedral oligomeric silsesquioxanes (POSS) - PS/PS-graft-POSS/POSS - with different grafting degrees were prepared by reactive melt processing using dicumyl peroxide (DCP) as initiator in the presence or absence of styrene monomer as radical transfer agent. Gel permeation chromatography (GPC) using triple-detector and proton nuclear magnetic resonance (NMR 1 H) analyses were used together to determine the conversion degree of PS-graft-POSS as a function of the reactive processing conditions adopted. GPC was employed to evaluate the effects of grafting (PS-graft-POSS) and PS chains degradation (β scission) that occur simultaneously during processing on the variation of average molecular masses and distributions for each PS/POSS sample. PS/POSS systems processed with styrene showed higher weight average molecular weights (M w ) and lower polydispersity indexes (M w /M n ), as a result of higher grafting (PS-graft-POSS) conversion (28-40%) and lower PS chain degradation level, as compared to PS/POSS systems processed without styrene in which the degree of grafting conversion was around 25-28%. (author)

  8. Enhancement of the grafting performance and of the water absorption of cassava starch graft copolymer by gamma radiation

    Kiatkamjornwong, Suda; Meechai, Nispa

    1997-01-01

    Enhancement of the gamma radiation grafting of acrylonitrile onto gelatinized cassava starch was investigated. Infrared spectrometry was used to follow the chemical changes in the grafting reaction and from saponification. The saponified starch-g-PAN (HSPAN) was then characterized in terms of grafting parameters to provide a guide for the optimum total dose (kGy) and the appropriate ratio of starch/acrylonitrile for a fixed dose rate of 2.5 x 10 -1 kGy/min. Other dose rates were also carried out to obtain the appropriate result of grafting copolymerization and of water absorption. A thin aluminium foil, covering the inner wall of the reaction vessel, was found to be far more effective than any other metal films in the enhancement of the grafting reaction and the water absorption as well. Nitric acid in the medium increases the grafting yield and the water absorption. Methyl ether hydroquinone inhibitor was evaluated for its ability to increase homopolymerization and decrease graft reaction. When styrene was used as a comonomer, it hampered the grafting of acrylonitrile onto starch backbone. The water absorption capacity was improved by freeze-drying the HSPAN. The treatment of the HSPAN with aluminium trichloride hexahydrate was found to enhance the degree of wicking, but to decrease the water absorbency. (author)

  9. Coronary artery bypass grafts: assessment of graft patency and native coronary artery lesions using 16-slice MDCT

    Stauder, Norbert I.; Drosch, Tanja; Claussen, Claus D.; Kopp, Andreas F. [Eberhard-Karls-University, Department of Diagnostic Radiology, Tuebingen (Germany); Kuettner, Axel [Friedrich-Alexander-University, Department of Diagnostic Radiology, Erlangen (Germany); Schroeder, Stephen; Beck, Torsten [Eberhard-Karls-University, Department of Internal Medicine, Division Cardiology, Tuebingen (Germany); Stauder, Heidrun [Eberhard-Karls-University, Department of Thoracic and Cardiovascular Surgery, Tuebingen (Germany); Blumenstock, Gunnar [Eberhard-Karls-University, Department of Medical Information Processing, Tuebingen (Germany)

    2006-11-15

    The objective of this study was to evaluate the accuracy of electrocardiography (ECG)-gated 16-slice multidetector-row computed tomography (MDCT) in detection of stenosis of bypass grafts and native coronary arteries in patients who have undergone coronary artery bypass grafting (CABG). ECG-gated contrast-enhanced MDCT using 12 x 0.75-mm collimation was performed in 20 patients with recurrent angina 4.75 years after undergoing CABG. A total of 50 grafts, 16 arterial and 34 venous, were examined. All graft and coronary segments were evaluated for stenosis in comparison with conventional coronary angiography (CCA). Among the 80 arterial graft segments, 62 could be assessed (77.5%). Sensitivity, specificity, and positive and negative predictive values for stenosis were 96.2%, 97.2%, 96.2%, and 97.2%, respectively. In a total of 180 venous graft segments, 167 could be assessed. Sensitivity, specificity, and positive and negative predictive values for stenosis were 98.5%, 93.9%, 91.8%, and 98.9%, respectively. MDCT could assess 179 of 260 native coronary artery segments (68.8%).Sensitivity, specificity, and positive and negative predictive values for stenosis were 92.1%, 76.9%, 87.5%, and 84.7%, respectively. Sixteen-slice MDCT provides excellent image quality and diagnostic accuracy in detection of graft and coronary artery lesions in patients with suspected graft dysfunction. (orig.)

  10. Two-Stage Liver Transplantation with Temporary Porto-Middle Hepatic Vein Shunt

    Giovanni Varotti

    2010-01-01

    Full Text Available Two-stage liver transplantation (LT has been reported for cases of fulminant liver failure that can lead to toxic hepatic syndrome, or massive hemorrhages resulting in uncontrollable bleeding. Technically, the first stage of the procedure consists of a total hepatectomy with preservation of the recipient's inferior vena cava (IVC, followed by the creation of a temporary end-to-side porto-caval shunt (TPCS. The second stage consists of removing the TPCS and implanting a liver graft when one becomes available. We report a case of a two-stage total hepatectomy and LT in which a temporary end-to-end anastomosis between the portal vein and the middle hepatic vein (TPMHV was performed as an alternative to the classic end-to-end TPCS. The creation of a TPMHV proved technically feasible and showed some advantages compared to the standard TPCS. In cases in which a two-stage LT with side-to-side caval reconstruction is utilized, TPMHV can be considered as a safe and effective alternative to standard TPCS.

  11. A new grafting technique for tympanoplasty: tympanoplasty with a boomerang-shaped chondroperichondrial graft (TwBSCPG).

    Dündar, Rıza; Soy, Fatih Kemal; Kulduk, Erkan; Muluk, Nuray Bayar; Cingi, Cemal

    2014-10-01

    The aim of this study was to introduce a new grafting technique in tympanoplasty that involves use of a boomerang-shaped chondroperichondrial graft (BSCPG). The anatomical and functional results were evaluated. A new tympanoplasty with boomerang-shaped chondroperichondrial graft (TwBSCPG) technique was used in 99 chronic otitis media patients with central or marginal perforation of the tympanic membrane and a normal middle ear mucosa. All 99 patients received chondroperichondrial cartilage grafts with a boomerang-shaped cartilage island left at the anterior and inferior parts. Postoperative follow-ups were conducted at months 1, 6, and 12. Preoperative and postoperative audiological examinations were performed and air-bone gaps were calculated according to the pure-tone averages (PTAs) of the patients. In the preoperative period, most (83.8%) air-bone gaps were ≥ 16 dB; after operating using the TwBSCPG technique, the air-bone gaps decreased to 0-10 dB in most patients (77.8%). In the TwBSCPG patients, the mean preoperative air-bone gap was 22.02 ± 6.74 dB SPL. Postoperatively, the mean postoperative air-bone gap was 8.70 ± 5.74 dB SPL. The TwBSCPG technique therefore decreased the postoperative air-bone gap compared to that preoperatively (p = 0.000, z = -8.645). At the 1-month follow-up, there were six graft perforations and one graft retraction. At the 6-month follow-up, there were nine graft perforations and three graft retractions. At 12 months, there were seven graft perforations and four graft retractions. During the first year after the boomerang tympanoplasty surgery, graft lateralization was not detected in any patient. Retractions were grade 1 according to the Sade classification and were localized to the postero-superior quadrant of the tympanic membrane. The TwBSCPG technique has benefits with respect to postoperative anatomical and audiological results. It prevents perforation of the tympanic membrane at the anterior quadrant and avoids graft

  12. Vancomycin graft composite for infected bone defects

    Winkler, H.; Janata, O.; Georgopoulos, A.

    1999-01-01

    Reconstructive surgery under septic conditions represents a major challenge in orthopaedics. Local application of antibiotics can provide high drug levels at the site of infection without systemic effects. However, removal of non-resorbable implants and filling of defects usually requires additional operative procedures. An ideal antibiotic carrier should provide for : 1) Effective bactericidal activity, especially against staphylococci including MRSA; 2) High and long lasting levels at the site of infection without local or systemic toxicity; 3) Repair of defects without a second stage procedure. Allogeneic cancellous bone is proven to be effective in restoration of bone stock. Vancomycin is effective against all gram-positive populations and the agent of choice for infections with MRSA. The aim of our study is to investigate the efficacy of a combination of both components in bone infection. Cancellous bone of human origin was processed during several steps and incubated in 10% vancomycin solution. The antimicrobial activity of the vancomycin graft composite (VGC) was evaluated using an agar diffusion bioassay against staphylococcus aureus and high performance liquid chromatography (HPLC). The testing period was up to 9 weeks. Elution of vancomycin from the graft was evaluated in 2.5% human albumin solution, which was exchanged every 24 hours. Concentration of vancomycin in allograft-bone was between 6.653[tg/g and 23.194gg/g with an average of 15.250 [tg/g, which is equivalent to 10.000 times the minimum inhibitory concentration (MIC) for s. aureus. The initial activity decreased to approx. 50% during the first week and approx. 30% at the end of the 9th week. The lowest values measured exceeded the MIC by 2000 times. Concentration in surrounding fluid decreased from 24.395,80 to 18,43pg/ml after 11 complete exchanges. Human cancellous bone, processed in an adequate way, offers capability to store high quantities of vancomycin. Vancomycin graft composites are

  13. Single-Center Experience Using Marginal Liver Grafts in Korea.

    Park, P-J; Yu, Y-D; Yoon, Y-I; Kim, S-R; Kim, D-S

    2018-05-01

    Liver transplantation (LT) is an established therapeutic modality for patients with end-stage liver disease. The use of marginal donors has become more common worldwide due to the sharp increase in recipients, with a consequent shortage of suitable organs. We analyzed our single-center experience over the last 8 years in LT to evaluate the outcomes of using so-called "marginal donors." We retrospectively analyzed the database of all LTs performed at our institution from 2009 to 2017. Only patients undergoing deceased-donor LTs were analyzed. Marginal grafts were defined as livers from donors >60 years of age, livers from donors with serum sodium levels >155 mEq, graft steatosis >30%, livers with cold ischemia time ≥12 hours, livers from donors who were hepatitis B or C virus positive, livers recovered from donation after cardiac death, and livers split between 2 recipients. Patients receiving marginal grafts (marginal group) were compared with patients receiving standard grafts (standard group). A total of 106 patients underwent deceased-donor LT. There were 55 patients in the standard group and 51 patients in the marginal group. There were no significant differences in terms of age, sex, Model for End-Stage Liver Disease score, underlying liver disease, presence of hepatocellular carcinoma, and hospital stay between the 2 groups. Although the incidence of acute cellular rejection, cytomegalovirus infection, and postoperative complications was similar between the 2 groups, the incidence of early allograft dysfunction was higher in the marginal group. With a median follow-up of 26 months, the 1-, 3-, and 5-year overall and graft (death-censored) survivals in the marginal group were 85.5%, 75%, and 69.2% and 85.9%, 83.6%, and 77.2%, respectively. Patient overall survival and graft survival (death-censored) were significantly lower in the marginal group (P = .023 and P = .048, respectively). On multivariate analysis, receiving a marginal graft (hazard ratio [HR

  14. Effect of solubility parameter of solvents on electron beam induced graft-polymerization onto polyethylene films

    Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

    1992-01-01

    Electron beam induced graft-polymerization by the mutual irradiation technique of methyl methacrylate (MMA) and methacrylic acid (MAAc) blended with solvents, which have different solubility parameters δ, onto high density polyethylene films (PE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic rations on the surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of solvents, and grafting rates for MMA were larger than those for MAAc. Graft chain contents on the surface, which were evaluated in terms of surface tensions and atomic ratios on the surface, increased with increasing δ of solvents, and graft chain contents on the surface of MAAc grafted PE were higher than those of MMA grafted PE. It is assumed that mutual solubility of PE and solvents (monomer solutions), i.e., infiltration of monomer solutions into PE during graft-polymerization, influenced grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

  15. An alternative graft fixation technique for scaphoid nonunions treated with vascular bone grafting.

    Korompilias, Anastasios V; Lykissas, Marios G; Kostas-Agnantis, Ioannis P; Gkiatas, Ioannis; Beris, Alexandros E

    2014-07-01

    To present our experience with vascularized bone grafting based on the 1,2-intercompartmental supraretinacular artery for the management of established scaphoid nonunion and to investigate the efficacy of graft immobilization with a combination of Kirschner wires and transarticular external fixation. A retrospective chart and radiographic review was conducted for patients with the diagnosis of scaphoid nonunion of the proximal pole or the waist treated with the 1,2-intercompartmental supraretinacular artery-based vascularized graft and fixed with a combination of Kirschner wires and transarticular external fixation between 2007 and 2011. We observed 23 consecutive patients for a mean of 34 ± 4 months. All patients were males with mean age of 25 ± 5 years. All patients had scaphoid nonunion and associated humpback deformity. The mean duration of nonunion was 7 ± 1 months. All scaphoid nonunions united after the index procedure at a mean of 10 ± 1 weeks. Two patients had avascular necrosis of the proximal pole based on the preoperative magnetic resonance imaging findings. After surgery, deformity correction was achieved in all patients, as recorded by the decrease in the lateral intrascaphoid angle and the increase in the dorsal scaphoid angle. At the last follow-up, no patients reported wrist pain. The mean Disabilities of the Arm, Shoulder, and Hand score improved significantly from 32 ± 12 before the operation to 5 ± 3 at the last postoperative visit. All patients showed statistically significant improvement in the range of motion and the grip strength of the involved wrist. The results of this study support the combined use of Kirschner wires and transarticular external fixation for fixation of a 1,2-intercompartmental supraretinacular artery-based vascular bone graft in the treatment of scaphoid nonunions. Therapeutic IV. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  16. Salt-Induced Control of the Grafting Density in Poly(ethylene glycol) Brush Layers by a Grafting-to Approach

    Ortiz, Roberto; Olsen, Stefan; Thormann, Esben

    2018-01-01

    In this work, a method to obtain control of the grafting density during the formation of polymer brush layers by the grafting-to method of thiolated poly(ethylene glycol) onto gold is presented. The grafting density of the polymer chains was adjusted by adding Na2SO4 in concentrations between 0.......2 and 0.9 M to the aqueous polymer solution during the grafting process. The obtained grafting densities ranged from 0.26 to 1.60 chains nm-2, as determined by surface plasmon resonance. The kinetics of the grafting process were studied in situ by a quartz crystal microbalance with dissipation......, and a mushroom to brush conformational transition was observed when the polymer was grafted in the presence of Na2SO4. The transition from mushroom to brush was only observed for long periods of grafting, highlighting the importance of time to obtain high grafting densities. Finally, the prepared brush layer...

  17. Vulvovaginal Graft-Versus-Host Disease.

    Kornik, Rachel I; Rustagi, Alison S

    2017-09-01

    Vulvovaginal chronic graft-versus-host disease (cGVHD) is an underrecognized complication of stem cell transplantation. Early recognition may prevent severe sequelae. Genital involvement is associated with oral, ocular, and skin manifestations. Treatment includes topical immunosuppression, dilator use, and adjuvant topical estrogen. Clinical and histologic features may mimic other inflammatory vulvar conditions. In the right clinical context, these findings are diagnostic of chronic GVHD. Female recipients of allo-hematopoietic stem cell transplantation (HCT) are at higher risk of condylomas, cervical dysplasia, and neoplasia. The National Institutes of Health publishes guidelines for the diagnosis, grading, management, and supportive care for HCT patients by organ system. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Lycopene and flesh colour differences in grafted and non-grafted watermelon

    Fekete D.

    2015-01-01

    Full Text Available The experiment was carried out in three regions in Hungary (Jászszentandrás, Cece, Újkígyós in 2013 to determine the fruit quality of grafted watermelon (Citrullus lanatus Thunb.. The “RX 467” seedless watermelon variety was grafted on two commercial rootstocks “FR STRONG” [Lagenaria siceraria (Mol. Standl.] and “RS 841” (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne. The lycopene and flesh colours are important quality characteristics even of the selfrooted and grafted watermelon. Some differences can be attributed to different environments, technological methods and to the type of rootstockscion combination. Lycopene is a strong antioxidant; therefore, we considered to examine the content change. Regardless of growing location, the lycopene concentration and the chroma (C* showed the best result in the case of interspecific rootstock. The result also showed that in two regions (Jászszentandrás, Cece we can find negative correlation between the lycopene concentration and the L* value of the flesh colour.

  19. Vascularized fibular graft in infected tibial bone loss

    C Cheriyan Kovoor

    2011-01-01

    Full Text Available Background : The treatment options of bone loss with infections include bone transport with external fixators, vascularized bone grafts, non-vascularized autogenous grafts and vascularized allografts. The research hypothesis was that the graft length and intact ipsilateral fibula influenced hypertrophy and stress fracture. We retrospectively studied the graft hypertrophy in 15 patients, in whom vascularized fibular graft was done for post-traumatic tibial defects with infection. Materials and Methods : 15 male patients with mean age 33.7 years (range 18 - 56 years of post traumatic tibial bone loss were analysed. The mean bony defect was 14.5 cm (range 6.5 - 20 cm. The mean length of the graft was 16.7 cm (range 11.5 - 21 cm. The osteoseptocutaneous flap (bone flap with attached overlying skin flap from the contralateral side was used in all patients except one. The graft was fixed to the recipient bone at both ends by one or two AO cortical screws, supplemented by a monolateral external fixator. A standard postoperative protocol was followed in all patients. The hypertrophy percentage of the vascularized fibular graft was calculated by a modification of the formula described by El-Gammal. The followup period averaged 46.5 months (range 24 - 164 months. The Pearson correlation coefficient (r was worked out, to find the relationship between graft length and hypertrophy. The t-test was performed to find out if there was any significant difference in the graft length of those who had a stress fracture and those who did not and to find out whether there was any significant difference in hypertrophy with and without ipsilateral fibula union. The Chi square test was performed to identify whether there was any association between the stress fracture and the fibula union. Given the small sample size we have not used any statistical analysis to determine the relation between the percentage of the graft hypertrophy and stress fracture. Results : Graft

  20. Laser-assisted fibrinogen bonding of umbilical vein grafts.

    Oz, M C; Williams, M R; Souza, J E; Dardik, H; Treat, M R; Bass, L S; Nowygrod, R

    1993-06-01

    Despite success with autologous tissue welding, laser welding of synthetic vascular prostheses has not been possible. The graft material appears inert and fails to allow the collagen breakdown and electrostatic bonding that results in tissue welding. To develop a laser welding system for graft material, we repaired glutaraldehyde-tanned human umbilical cord vein graft incisions using laser-assisted fibrinogen bonding (LAFB) technology. Modified umbilical vein graft was incised transversely (1.2 cm). Incisions were repaired using sutures, laser energy alone, or LAFB. For LAFB, indocyanine green dye was mixed with human fibrinogen and the compound applied with forceps onto the weld site prior to exposure to 808 nm diode laser energy (power density 4.8 W/cm 2). Bursting pressures for sutured repairs (126.6 +/- 23.4 mm Hg) were similar to LAFB anastomoses (111.6 +/- 55.0 mm Hg). No evidence of collateral thermal injury to the graft material was noted. In vivo evaluation of umbilical graft bonding with canine arteries demonstrates that LAFB can reliably reinforce sutured anastomoses. The described system for bonding graft material with laser exposed fibrinogen may allow creation or reinforcement of vascular anastomoses in procedures where use of autologous tissue is not feasible.

  1. Satisfactory surgical option for cartilage graft absorption in microtia reconstruction.

    Han, So-Eun; Oh, Kap Sung

    2016-04-01

    We routinely perform auricular elevation at least 6 months after implantation of framework in microtia reconstruction using costal cartilage. However, in a few cases, cartilage graft absorption has occurred, which has led to contour irregularity with unfavorable long-term results. In the present study, we recount the details of using additional rib cartilage augmentation to achieve an accentuated contour in cartilage graft absorption cases. The cartilage graft absorption was defined as contour irregularity or cartilage graft deformation as evaluated by the surgeon and patient. Depending on the extent of cartilage graft absorption, another rib cartilage framework was added to the previously implanted framework, targeting the absorption area. We used banked cartilage or harvested new cartilage based on three-dimensional rib computed tomography. Additional recontouring of framework was conducted in eight patients who were examined for cartilage graft absorption from 1.5 to 5 years after implantation of the framework. Four patients received additional rib cartilage augmentation and tissue expander insertion simultaneously prior to auricular elevation. Two patients underwent auricular elevation simultaneously. In another two patients, additional rib cartilage augmentation was performed before auricular elevation. The mean follow-up period was 18 months, and in all cases reconstructive results were acceptable. Although further follow-up evaluation is required, additional rib cartilage augmentation is an attractive surgical option for cartilage graft absorption cases. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  2. Computed tomography evaluation of autogenous graft in sinus lift surgery

    Ajzen, Sergio Aron; Moscatiello, Rafael Andrade; Lima, Aida Maria Custodio de; Moscatiello, Vitoria Aparecida Muglia; Helio Kiitiro Yamashita; Mosacatiello, Rafael Muglia; Nishiguchi, Celso Itiro; Alves, Maria Teresa de Seixas

    2001-01-01

    The objective was to quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from apheresis or centrifugation using computed tomography. This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months), with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental implant. All patients were submitted to computed tomography examinations prior and six months after sinus lift surgery. Fifty-three maxillary sinuses were operated and divided into three distinct groups: autogenous bone graft, autogenous bone graft in combination with platelet-rich plasma obtained by centrifugation, and autogenous bone graft in combination with platelet-rich plasma obtained by apheresis. The results showed that computed tomography demonstrated bone growth in height and width between the initial and the follow-up computed tomography scans in all three groups. However, no statistical difference was found either for bone height or width. It was concluded that clinical evidence demonstrates the effectiveness of autogenous bone grafts, particularly when used in combination with bone growth factors such as platelet-rich plasma, which allow prosthetic and functional restoration of maxillofacial structures through fixation of dental implants. (author)

  3. Proximal tubular dysfunction as an indicator of chronic graft dysfunction

    N.O.S. Câmara

    2009-03-01

    Full Text Available New strategies are being devised to limit the impact of renal sclerosis on graft function. Individualization of immunosuppression, specifically the interruption of calcineurin-inhibitors has been tried in order to promote better graft survival once chronic graft dysfunction has been established. However, the long-term impact of these approaches is still not totally clear. Nevertheless, patients at higher risk for tubular atrophy and interstitial fibrosis (TA/IF development should be carefully monitored for tubular function as well as glomerular performance. Since tubular-interstitial impairment is an early event in TA/IF pathogenesis and associated with graft function, it seems reasonable that strategies directed at assessing tubular structural integrity and function would yield important functional and prognostic data. The measurement of small proteins in urine such as α-1-microglobulin, N-acetyl-beta-D-glucosaminidase, alpha/pi S-glutathione transferases, β-2 microglobulin, and retinol binding protein is associated with proximal tubular cell dysfunction. Therefore, its straightforward assessment could provide a powerful tool in patient monitoring and ongoing clinical assessment of graft function, ultimately helping to facilitate longer patient and graft survival associated with good graft function.

  4. Chronologic changes of free fat graft in rabbit using CT

    Kondo, Norihiro; Kurita, Kenichi; Yajima, Tetsuya; Izumi, Masahiro

    2008-01-01

    Free fat grafts are now used for preventing osteal readhesion, filling dead space, and protecting grafted nerves and vessels. However, it is reported that grafted fat tissue is unstable resulting in high risk of cicatrization and infection. We grafted free fat to a rabbit's back and observed the chronologic change using CT. Ten adult male Japanese white rabbits (3.5 kg) were used. In five rabbits, fat tissue was obtained from the back under general anaesthesia, and transplanted into the back about 50 mm posterior from the donor site. CT was taken in the fixed scan condition five times (preoperation, immediate postoperation, postoperative 1-month, 2-month, and 3-month). In the remaining five rabbits, only CT scan was taken three times as a control. It was observed that we compared preoperative fat volume with the postoperative volume using RealINTAGE. Grafted fat tissue decreased postoperatively at 1-month and completely disappeared at 3-months. We were able to prove that CT scan is effective to observe the chronologic change of grafted fat tissue. Techniques of tissue engineering are necessary for survival of grafted fat tissue. (author)

  5. Improvement of the polymer stability by radiation grafting

    Ranogajec, F.; Mlinac-Misak, M.

    2004-01-01

    Losses of the stabilizer due to extractability or volatility immediately affect the ultimate performance of polymer products. A new approach to increase the persistence of the stabilizer in the final product is to chemically bind it to the polymer backbone. Radiation grafting or crosslinking could be an efficient method for this, when the stabilizer is polymerizable. By a mutual gamma irradiation method photoprotector 2-hydroxy-4-(3-methacryloxy-2-hydroxy-propoxy) benzophenone has been readily grafted to low-density polyethylene in benzene, tetrahydrofuran and methanol solution, respectively. Surface grafting occurs in a methanol solution of stabilizer, while in benzene and tetrahydrofuran solutions of the stabilizer, grafting proceeds more or less in the inner parts of the polymeric film as well. UV stability tests and changes in the mechanical properties of artificially and naturally aged films indicate pronounced protective effect achieved by the grafted stabilizer. Surface grafting is an efficient photostabilization method since the grafted stabilizer is chemically bound to a polymeric surface and in this way the problem of evaporation of blended stabilizers during the prolonged use of polymeric materials is eliminated

  6. Skin Graft Fixation Using Hydrofiber (Aquacel® Extra).

    Yen, Ya-Hui; Lin, Chih-Ming; Hsu, Honda; Chen, Ying-Chen; Chen, Yi-Wen; Li, Wan-Yu; Hsieh, Chia-Nan; Huang, Chieh-Chi

    2018-06-01

    The traditional method of skin graft fixation is with tie-over bollus dressing. The use of splints in the extremities for skin graft fixation is a common practice. However, these splints are heavy and uncomfortable and contribute considerably to our overall medical waste. Hydrofiber (Aquacel Extra) has a strong fluid absorption property and fixates well to the underlying wound once applied. In this study, we used hydrofiber for fixation, avoiding the use of splints after skin grafting. A total of 56 patients reconstructed with split-thickness skin graft that was fixated only with hydrofiber between March 2015 and March 2016 were included in this retrospective study. There were 44 men and 12 women with a mean age of 61 ± 18 years. The defect size ranged from 1 × 1 cm for fingertips to 30 × 12 cm for lower limb defects. The average defect size was 61 ± 78 cm. The mean skin graft take was 96% ± 6%. Because splints were not required, we saved around 48 kg of medical waste over the space of 1 year. The use of hydrofiber for skin graft fixation was effective and technically very simple. Splints were not required with this method, decreasing the medical waste created and increasing patient comfort. We suggest that this is an excellent alternative for skin graft fixation while at the same time decreasing our carbon footprint as surgeons.

  7. [Features of skin graft in pediatric plastic surgery].

    Depoortère, C; François, C; Belkhou, A; Duquennoy-Martinot, V; Guerreschi, P

    2016-10-01

    Skin graft is a skin tissue fragment transferred from a donor site to a receiving site with a spontaneous revascularization. Basic process of plastic surgery, skin graft known in children, specific, warnings and refinements. It finds its indication in many pediatric cases: integumental diseases (neavus, hamartoma), acute burns and scars, traumatic loss of substance or surgically induced, congenital malformations of the hands and feet, etc. Specific skin graft techniques in children are developed: donor sites, sampling technique and procedure, early postoperative care. Especially in children, the scalp is a perfect site for split skin graft and technique is actively developed. Refinements and special cases are discussed: use of dermal matrices, allografts, xenografts, negative pressure therapy, prior skin expansion of the donor site. Results of skin graft in children are exposed: taking of graft, growth and shrinkage, pigmentation. Skin graft sometimes allows to stay the complex movement and get the best final benefit, permanent or at least temporary, in a growing being. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. A Review on Grafting of Biofibers for Biocomposites.

    Wei, Liqing; McDonald, Armando G

    2016-04-22

    A recent increase in the use of biofibers as low-cost and renewable reinforcement for the polymer biocomposites has been seen globally. Biofibers are classified into: lignocellulosic fibers ( i.e. , cellulose, wood and natural fibers), nanocellulose ( i.e. , cellulose nanocrystals and cellulose nanofibrils), and bacterial cellulose, while polymer matrix materials can be petroleum based or bio-based. Green biocomposites can be produced using both biobased fibers and polymers. Incompatibility between the hydrophilic biofibers and hydrophobic polymer matrix can cause performance failure of resulting biocomposites. Diverse efforts have focused on the modification of biofibers in order to improve the performances of biocomposites. "Grafting" copolymerization strategy can render the advantages of biofiber and impart polymer properties onto it and the performance of biocomposites can be tuned through changing grafting parameters. This review presents a short overview of various "grafting" methods which can be directly or potentially employed to enhance the interaction between biofibers and a polymer matrix for biocomposites. Major grafting techniques, including ring opening polymerization, grafting via coupling agent and free radical induced grafting, have been discussed. Improved properties such as mechanical, thermal, and water resistance have provided grafted biocomposites with new opportunities for applications in specific industries.

  9. Percutaneous treatment of complications occurring during hemodialysis graft recanalization

    Sofocleous, Constantinos T. E-mail: constant@pol.net; Schur, Israel; Koh, Elsie; Hinrichs, Clay; Cooper, Stanley G.; Welber, Adam; Brountzos, Elias; Kelekis, Dimitris

    2003-09-01

    Introduction/objective: To describe and evaluate percutaneous treatment methods of complications occurring during recanalization of thrombosed hemodialysis access grafts. Methods and materials: A retrospective review of 579 thrombosed hemodialysis access grafts revealed 48 complications occurring during urokinase thrombolysis (512) or mechanical thrombectomy (67). These include 12 venous or venous anastomotic ruptures not controlled by balloon tamponade, eight arterial emboli, 12 graft extravasations, seven small hematomas, four intragraft pseudointimal 'dissections', two incidents of pulmonary edema, one episode of intestinal angina, one procedural death, and one distant hematoma. Results: Twelve cases of post angioplasty ruptures were treated with uncovered stents of which 10 resulted in graft salvage allowing successful hemodialysis. All arterial emboli were retrieved by Fogarty or embolectomy balloons. The 10/12 graft extravasations were successfully treated by digital compression while the procedure was completed and the graft flow was restored. Dissections were treated with prolonged Percutaneous Trasluminal Angioplasty (PTA) balloon inflation. Overall technical success was 39/48 (81%). Kaplan-Meier Primary and secondary patency rates were 72 and 78% at 30, 62 and 73% at 90 and 36 and 67% at 180 days, respectively. Secondary patency rates remained over 50% at 1 year. There were no additional complications caused by these maneuvers. Discussions and conclusion: The majority of complications occurring during percutaneous thrombolysis/thrombectomy of thrombosed access grafts, can be treated at the same sitting allowing completion of the recanalization procedure and usage of the same access for hemodialysis.

  10. Radiation-induced grafting of styrene on polypropylene pellets

    Souza, Camila P.; Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.

    2009-01-01

    The changes of radiation-induced in polypropylene (PP) pellets exposed to gamma irradiation in inert atmosphere were investigated in correlation with the applied doses (10 and 50 kGy). Also, results from the grafting of styrene onto PP pellets using simultaneous irradiation at the same doses are presented. The grafting reaction was carried out using toluene as solvent, under nitrogen atmosphere and at room temperature. The properties of the irradiated and grafted PP pellets were studied using Melt Flow Index, thermal analysis (TG and DSC), and ATR-IR. The degree of grafting (DOG) for the grafted pellets was gravimetrically determined. The results showed that radiation-induced graft polymerization on pellets were successfully obtained and the influence of dose irradiated did not change the thermal properties in spite of the increase in the MFI and consequently this increase in the viscosity results an decrease the molecular mass. The MFI for grafted pellets was not achievable because the high degree of viscosity of polymer, even arising the test temperature, the polymer was not flow enough. (author)

  11. Grafting of activated carbon cloths for selective adsorption

    Gineys, M.; Benoit, R.; Cohaut, N.; Béguin, F.; Delpeux-Ouldriane, S., E-mail: delpeux@cnrs-orleans.fr

    2016-05-01

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

  12. Salmonella Typhimurium gastroenteritis leading to chronic prosthetic vascular graft infection.

    Cullinan, Milo; Clarke, Michael; Dallman, Tim; Peart, Steven; Wilson, Deborah; Weiand, Daniel

    2017-08-01

    Introduction. It is estimated up to 6 % of prosthetic vascular grafts become infected. Staphylococcus aureus is predominant in early infection and coagulase-negative staphylococci are predominant in late infections. Enterobacteriaceae cause 14-40 % of prosthetic vascular graft infections. This is, to our knowledge the first reported case of Salmonella gastroenteritis causing chronic prosthetic vascular graft infection (PVGI). Case presentation. A 57 years old lady presented with signs and symptoms of prosthetic vascular graft infection. Three years earlier, she had undergone a prosthetic axillo-femoral bypass graft for critical limb ischaemia. The infected prosthetic vascular graft was removed and Salmonella Typhimurium was isolated on culture. In the intervening period, Salmonella Typhimurium was isolated from a faecal specimen, collected during an episode of acute gastroenteritis. Whole-genome sequencing (WGS) showed that the respective Salmonella Typhimurium isolates differed by only a single nucleotide polymorphism (SNP). Salmonella Typhimurium was not isolated on culture of a faecal specimen collected five days following cessation of antimicrobial therapy. Six months after removal of the prosthetic graft, the patient remains under follow-up for her peripheral vascular disease, which currently requires no further surgical intervention. Conclusion. This case has clear implications for the management of chronic PVGI. It is vital to collect high-quality surgical specimens for microbiological analysis and empirical choices of antibiotics are unlikely to cover all potential pathogens. It may also be prudent to enquire about a history of acute gastroenteritis when assessing patients presenting with chronic PVGI.

  13. Albumin grafting on biomaterial surfaces using gamma-irradiation

    Kamath, K.R.

    1993-01-01

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

  14. One Year Outcomes of 101 BeGraft Stent Grafts used as Bridging Stents in Fenestrated Endovascular Repairs.

    Spear, Rafaelle; Sobocinski, Jonathan; Hertault, Adrien; Delloye, Matthieu; Azzauiu, Richard; Fabre, Dominique; Haulon, Stéphan

    2018-04-01

    To evaluate the outcomes of the second generation BeGraft balloon expandable covered stent Graft System (Bentley InnoMed, Hechingen, Germany) implanted as bridging stent grafts during fenestrated endovascular aortic repair (FEVAR) of complex aneurysms. This was a single centre prospective study including all consecutive patients treated by FEVAR performed with second generation BeGraft stent grafts as bridging stents. Demographics of patients, diameter and length of the bridging stent grafts, technical success, re-interventions, occlusions, post-operative events, and imaging (Cone Beam CT and/or CT scan, and contrast enhanced ultrasound) were prospectively collected in an electronic database. Duplex ultrasound was performed before discharge and at 6 month follow-up. At 1 year, patients were evaluated clinically and by imaging (CT and ultrasound). Between November 2015 and September 2016, 39 consecutive patients (one woman) were treated with custom made fenestrated endografts (2-5 fenestrations) for complex aneurysms or type 1 endoleak after EVAR, using a variety of bridging stents including the BeGraft. All 101 BeGraft stent grafts were successfully delivered and deployed. There was no in hospital mortality. Early fenestration patency rate was 99% (96/97); the sole target vessel post-operative occlusion was secondary to a dissection of the renal artery distal to the stent. Complementary stenting was unsuccessful in recovering renal artery patency; bilateral renal stent occlusion was observed in the same patient on a CT scan performed 2 months after the procedure. He required post-operative dialysis. No additional renal impairment was observed. During follow-up (median 13 months [11-15]), all fenestrations stented with BeGraft stent grafts remained patent (95/97, 98%). One type 1b endoleak was detected and treated (2.6%). BeGraft stent grafts used as bridging stents during FEVAR are associated with favourable outcomes at 1 year follow-up. Long-term follow-up is

  15. Magnetizable stent-grafts enable endothelial cell capture

    Tefft, Brandon J. [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Uthamaraj, Susheil [Division of Engineering, Mayo Clinic, Rochester, MN (United States); Harburn, J. Jonathan [School of Medicine, Pharmacy and Health, Durham University, Stockton-on-Tees (United Kingdom); Hlinomaz, Ota [Department of Cardioangiology, St. Anne' s University Hospital, Brno (Czech Republic); Lerman, Amir [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Dragomir-Daescu, Dan [Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN (United States); Sandhu, Gurpreet S., E-mail: sandhu.gurpreet@mayo.edu [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States)

    2017-04-01

    Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance. - Highlights: • Magnetic stent-grafts were made from 2205 steel stents and polyurethane nanofibers. • Stent-grafts remained patent and formed a thin and uniform neointima when implanted. • Stent-grafts captured endothelial cells labeled with magnetic nanoparticles.

  16. Surveillance Duplex Ultrasonography of Stent Grafts for Popliteal Aneurysms.

    Pineda, Danielle M; Troutman, Douglas A; Dougherty, Matthew J; Calligaro, Keith D

    2016-05-01

    Stent grafts, also known as covered stents, have become an increasingly acceptable treatment for popliteal artery aneurysms. However, endovascular exclusion confers lower primary patency compared to traditional open bypass and exclusion. The purpose of this study was to evaluate whether duplex ultrasonography (DU) can reliably diagnose failing stent grafts placed for popliteal artery aneurysms prior to occlusion. Between June 5, 2007, and March 11, 2014, 21 stent grafts (Viabahn; Gore, Flagstaff, Arizona) were placed in 19 patients for popliteal artery aneurysms. All patients had at least 1 follow-up duplex scan postoperatively. Mean follow-up was 28.9 months (9-93 months). Postoperative DU surveillance was performed in our Intersocietal Accreditation Commission noninvasive vascular laboratory at 1 week postprocedure and every 6 months thereafter. Duplex ultrasonography measured peak systolic velocities (PSVs) and ratio of adjacent PSVs (Vr) every 5 cm within the stent graft and adjacent arteries. We retrospectively classified the following factors as "abnormal DU findings": focal PSV > 300 cm/s, uniform PSVs 3.0. These DU criteria were derived from laboratory-specific data that we previously published on failing stent grafts placed for lower extremity occlusive disease. Four of the 21 stent grafts presented with symptomatic graft thrombosis within 6 months of a normal DU. Three of these 4 patients presented with rest pain and underwent thrombectomy (2) or vein bypass (1), and 1 elected for nonintervention for claudication. Our results suggest that surveillance DU using criteria established for grafts placed for occlusive disease may not be useful for predicting stent graft failure in popliteal artery aneurysms. © The Author(s) 2016.

  17. Synthesis of ion-exchange membranes by radiation-induced multiple grafting of methyl α,β,β-trifluoroacrylate

    Omichi, H.; Okamoto, J.

    1982-01-01

    Methyl α,β,β-trifluoroacrylate (MTFA) was grafted onto polymer films with the multiple grafting technique initiated by γ-rays: the yields were similar to those of the single-step grafting procedure with any irradiation dose. Grafted polymer obtained in the single-step experiments were distributed mainly near the film surface, whereas graft polymer from the multiple grafting experiments were distributed uniformly in the film at graft yields greater than 20%. The electric resistance of the hydrolyzed multiple graft polymer film in a 2N NaOH solution was much lower than that of one-step graft film at the same graft yield

  18. Nickel adsorption by sodium polyacrylate-grafted activated carbon

    Ewecharoen, A. [Division of Biotechnology, School of Bioresources and Technology, King Mongkut' s University of Technology Thonburi, 83 Moo 8 Thakham, Bangkhuntien, Bangkok 10150 (Thailand); Thiravetyan, P., E-mail: paitip@hotmail.com [Division of Biotechnology, School of Bioresources and Technology, King Mongkut' s University of Technology Thonburi, 83 Moo 8 Thakham, Bangkhuntien, Bangkok 10150 (Thailand); Wendel, E.; Bertagnolli, H. [Institut fuer Physikalische Chemie, Universitaet Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany)

    2009-11-15

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

  19. [Graft hybridization and the specificity of heredity in fruit trees].

    Liu, Yong-Sheng; Li, Bao-Yin; Li, Gui-Rong; Zhou, Xiu-Mei

    2004-09-01

    Emphatically discusses the relationship between graft hybridization and the specificity of heredity in fruit trees on the basis of introducing the recent achievements in plant graft hybridization. We propose that genetic materials in rootstock being translocated and integrated into the genome of the germ cells and embryonic cells in scion are the main reasons why the majority of the hybrid seedlings have wild properties and the heredity of fruit trees violate Mendel's laws of heredity. The potential of graft hybridization in fruit breeding are also discussed.

  20. Kidney graft rejection studies with labeled platelets and lymphocytes

    Martin-Comin, J.

    1986-01-01

    The usefulness of In-111-labelled platelets and lymphocyte scintigraphy in acute kidney graft rejection is evaluated in 155 patients. Blood cells were labelled with 100-150 uCi of In-111-oxine and reinjected. Subsequently patients were scanned once daily from 2 hours post-reinjection up to a week. The graft/contralateral area activity ratio was calculated in all scans. It is concluded that In-111-labelled platelets scintigraphy is nowadays the method of choice for acute kidney graft rejection diagnosis, especially in patients under cyclosporine immunosuppression. (author)

  1. Influences of irradiation on the anastomotic sites of artificial graft

    Ogawa, Junichi; Inoue, Hiroshi; Koide, Shirosaku; Kawada, Shimei; Shotsu, Akira

    1989-01-01

    To examine the acute influences of irradiation on the anastomotic sites of EPTFE vascular grafts, experimental study was performed using canine dogs. After replacement of superior vena cava and bilateral femoral arteries with EPTFE grafts, a total of 20 to 100 Gy doses were given at the anastomotic sites of superior vena cava and right femoral artery. There were no degradation of grafts themselves or rupture in the anastomoses at cumulative anastomotic sites of superior vena cava, stenoses and/or overgrowth of granulation tissues were observed, although at those of right femoral artery, no remarkable differences were observed between dogs which received irradiation and those which did not receive. (author)

  2. Modification of natural leather by grafting emulsion copolymerization technique

    Badran, A.S.; Nasr, H.E.; El-Halawany, N.R.; Mohamed, W.S.

    2005-01-01

    Grafting emulsion copolymerization of methyl methacrylate (MMA) with butyl acrylate of different molar ratios onto natural leather with different molar ratios was carried out using developed redox initiation system of potassium persulphate (PPS) as an oxidizing agent and some sodium bisulphite adducts as reducing agent, as well as sodium dodecyl sulphate (SDS) was used as an anionic emulsifier. The grafted leather was characterized via FTIR, SEM and thermal gravimetric analysis. Moreover, the grafted leather was evaluated through water absorption, tensile strength, dyeing performance and hardness measurements. The obtained results revealed that the physical and mechanical properties of the modified leather were enhanced

  3. Importance of mesenchymal stem cells in autologous fat grafting

    Trojahn Kølle, Stig-Frederik; Oliveri, Roberto S; Glovinski, Peter Viktor

    2012-01-01

    the fat graft with adipose tissue-derived mesenchymal stem cells (ASC) before transplantation. We have reviewed original studies published on fat transplantation enriched with ASC. We found four murine and three human studies that investigated the subject after a sensitive search of publications....... In the human studies, so-called cell assisted lipotransfer (CAL) increased the ASC concentration 2-5 times compared with non-manipulated fat grafts, which caused a questionable improvement in survival of fat grafts, compared with that of traditional lipofilling. In contrast, in two of the murine studies ASC...

  4. Amino acids grafting of Ar+ ions modified PE

    Svorcik, V.; Hnatowicz, V.; Stopka, P.; Bacakova, L.; Heitz, J.; Oechsner, R.; Ryssel, H.

    2001-01-01

    Polyethylene (PE) was irradiated with 63 keV Ar + ions to the fluences from 1x10 12 to 3x10 15 cm -2 and then grafted at room temperature from water solution with amino acids (alanine, leucine). Using various spectroscopic techniques (UV-VIS, FTIR, RBS and EPR) it was shown that the amino acids penetrate into PE where they are eventually captured either on double bonds or on free radicals created by the ion irradiation. Grafting with amino acids in the whole specimen layer modified by irradiation is observed. The ion-beam-modified and amino-acid grafted PE is supposed to exhibit increased biocompatibility. (author)

  5. Phthalate Migration Study from PVC Grafted by Gamma Radiation

    Manzoli, J.E.; Duarte, C.; Somesari, E.; Silveira, C.; Paes, H.A.; Manzoli, J.E.; Araujo, F.D.C.; Panzarini, L.C.G.A.

    2009-01-01

    PVC is a useful polymer used for many applications, as packaging of food, blood and in contact with body fluids. The most widely-used plasticizer, to make it flexible, is the phthalate DEHP, and its toxicity is a problem. A special radiation grafting of PVC allows an important reduction of thrombogenic properties, and it could cause changes in the DEHP migration too. In this work it is presented the methodology using gas chromatography and numerical simulation for the measurement of DEHP migration from PVC grafted with monomer DMAEMA. The grafting could be an interesting way to reduce DEHP migration

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

    Ho, Derek; Jagdeo, Jared

    2015-11-01

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

  7. Acromioclavicular joint reconstruction using a tendon graft: a biomechanical study comparing a novel “sutured throughout” tendon graft to a standard tendon graft

    Naziri Qais

    2016-01-01

    Full Text Available Background: With a recurrence rate of over 30%, techniques that offer stronger acromioclavicular (AC joint reconstruction through increased graft strength may provide longevity. The purpose of our study was to determine the biomechanical strength of a novel tendon graft sutured throughout compared to a native tendon graft in Grade 3 anatomical AC joint reconstruction. Methods: For this in vitro experiment, nine paired (n = 18 embalmed cadaveric AC joints of three males and six females (age 86 years, range 51–94 years were harvested. Anatomic repair with fresh bovine Achilles tendon grafts without bone block was simulated. Specimens were divided into two groups; with group 1 using grafts with ultra-high molecular-weight polyethylene (UHMWPE suture ran throughout the entire length. In group 2, reconstruction with only native allografts was performed. The distal scapula and humerus were casted in epoxy compound and mounted on the mechanical testing machine. Tensile tests were performed using a mechanical testing machine at the rate of 50 mm/min. Maximum load and displacement to failure were collected. Results: The average load to failure was significantly higher for group 1 compared to group 2, with mean values of 437.5 N ± 160.7 N and 94.4 N ± 43.6 N, (p = 0.001. The average displacement to failure was not significantly different, with 29.7 mm ± 10.6 mm in group 1 and 25 mm ± 9.1 mm in group 2 (p = 0.25. Conclusion: We conclude that a UHMWPE suture reinforced graft can provide a 3.6 times stronger AC joint reconstruction compared to a native graft.

  8. Inverse cutting of posterior lamellar corneal grafts by a femtosecond laser

    Hjortdal, Jesper; Nielsen, Esben; Vestergaard, Anders Højslet

    2012-01-01

    (range: 1.400 to 2.000 cells per sq. mm). The grafts were of uniform thickness, but substantial interface haze was present in most grafts. Conclusions: Posterior lamellar corneal grafts can be prepared from the endothelial side using a femto-second laser. All grafts were clear after 6 months...

  9. Hydrophilicity improvement of polyethersulfone membranes by grafting methacrylic acid with γ-ray irradiation

    Li Jing; Hou Zhengchi; Xie Leidong; Zhang Fengying; Deng Bo

    2005-01-01

    Grafting methyacrylic acid onto poly(ether sulfone) membranes was realized by means of simultaneous irradiation in liquids. The modified membranes with different grafting ratios were obtained by changing the concentration of methyacrylic acid. It was shown that the grafting ratio increased lineally as the monomer concentration was less than 10% and hydrophilicity of the membranes was improved with increasing grafting ratios. (authors)

  10. Fluoropolymer-coated dacron versus PTFE grafts for femorofemoral crossover bypass: randomised trial

    Eiberg, JP; Røder, Ole Christian; Stahl-Madsen, M

    2006-01-01

    To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery.......To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery....

  11. Breeding graft-compatible Douglas-fir rootstocks (Pseudotsuga menziesii (Mirb.) Franco).

    D.L. Copes

    1999-01-01

    A study encompassing 24 years was conducted to determine if a breeding program could produce highly graft-compatible rootstocks. Twenty-seven trees of apparent high graft compatibility were selected and crossed to produce 226 control-pollinated families. Seedlings were grown, field planted, and grafted with test scions. Graft unions from field tests were evaluated...

  12. Comparative Proteomic Analysis of the Graft Unions in Hickory (Carya cathayensis Provides Insights into Response Mechanisms to Grafting Process

    Daoliang Yan

    2017-04-01

    Full Text Available Hickory (Carya cathayensis, a tree with high nutritional and economic value, is widely cultivated in China. Grafting greatly reduces the juvenile phase length and makes the large scale cultivation of hickory possible. To reveal the response mechanisms of this species to grafting, we employed a proteomics-based approach to identify differentially expressed proteins in the graft unions during the grafting process. Our study identified 3723 proteins, of which 2518 were quantified. A total of 710 differentially expressed proteins (DEPs were quantified and these were involved in various molecular functional and biological processes. Among these DEPs, 341 were up-regulated and 369 were down-regulated at 7 days after grafting compared with the control. Four auxin-related proteins were down-regulated, which was in agreement with the transcription levels of their encoding genes. The Kyoto Encyclopedia of Genes and Genomes (KEGG analysis showed that the ‘Flavonoid biosynthesis’ pathway and ‘starch and sucrose metabolism’ were both significantly up-regulated. Interestingly, five flavonoid biosynthesis-related proteins, a flavanone 3-hyfroxylase, a cinnamate 4-hydroxylase, a dihydroflavonol-4-reductase, a chalcone synthase, and a chalcone isomerase, were significantly up-regulated. Further experiments verified a significant increase in the total flavonoid contents in scions, which suggests that graft union formation may activate flavonoid biosynthesis to increase the content of a series of downstream secondary metabolites. This comprehensive analysis provides fundamental information on the candidate proteins and secondary metabolism pathways involved in the grafting process for hickory.

  13. Renal vessel reconstruction in kidney transplantation using a polytetrafluoroethylene (PTFE) vascular graft.

    Kamel, Mohamed H; Thomas, Anil A; Mohan, Ponnusamy; Hickey, David P

    2007-04-01

    We report a rare experience in reconstructing short renal vessels in kidney transplantation using polytetrafluroethylene (PTFE) vascular grafts. The short renal vessels in three kidney grafts were managed by the interposition of PTFE vascular grafts. Two grafts were from deceased donors and the third was a renal auto-transplant graft. PTFE grafts were used to lengthen short renal veins in two kidney grafts and a short renal artery in one. The warm ischaemia time was under 1 h and all kidneys functioned well post-operatively. Excellent blood perfusion in the three renal grafts was present on postoperative MAG 3 renal scan. No intra-operative or post-operative complications were encountered. In the three described patients, the use of PTFE vascular graft presented no additional morbidity to the kidney transplant operation and no post-oerative complication was related to its use. However, more data are necessary to conclude that PTFE graft can be used safely in kidney transplantation.

  14. Bone formation in cranial, mandibular, tibial and iliac bone grafts in rats

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

    1995-01-01

    Several studies have suggested that grafts from membranous derived bone (e.g., calvarial grafts) retain their volume better than those from endochondral derived bone (e.g., iliac bone grafts). Increased osteogenesis in grafts of the former type has been offered as the explanation. However, simple...... volume measurements of the recovered grafts do not differentiate between viable and dead bone. We studied fresh syngeneic full-thickness bone grafts from calvaria, mandibula, tibia diaphysis, and iliac bone implanted in the back muscles of young Lewis rats. Bone formation in grafts recovered 3 weeks...... that the anatomical area of harvest is important regarding new bone formation in syngeneic bone grafts. However, the results do not support the contention that better maintenance of volume of calvarial grafts compared with iliac bone grafts is due to enhanced osteogenesis in the former....

  15. Modification of polyetherurethane for biomedical application by radiation induced grafting. II. Water sorption, surface properties, and protein adsorption of grafted films

    Jansen, B.; Ellinghorst, G.

    1984-01-01

    A series of polyetherurethane films grafted by means of gamma radiation with hydrophilic or reactive monomers (2-hydroxyethyl methacrylate, 2,3-epoxypropyl methacrylate, 2,3-dihydroxypropyl methacrylate, and acrylamide) and partially chemically modified were subjected to various physico-chemical investigation methods involving water sorption, contact angle, and protein adsorption measurements. From contact angle data the interfacial free energy gamma sw between grafted films and water was calculated. It was found that the water uptake of grafted films increases with grafting yield or, in the case of grafted and afterwards chemically modified films, with reaction yield; the diffusion coefficient of water in the modified films also increases with grafting yield. Contact angle studies revealed all grafted films to have surfaces more hydrophilic than the ungrafted trunk polymer. The degree of hydrophilicity--especially of HEMA-grafted films--strongly depends on grafting conditions. For some grafted samples with high surface hydrophilicity very low interfacial free energies approaching zero were measured. The study of the competitive adsorption of bovine serum albumin, gamma-globulin, and fibrinogen from a synthetic protein solution onto modified films showed that the adsorption of albumin increases markedly with increasing grafting yields, whereas the fibrinogen and gamma-globulin adsorption only slightly increases. A correlation between interfacial free energy and protein adsorption in the sense of the minimum interfacial free energy hypothesis was found only for samples with grafting yields below 5%. At higher grafting yields the increased surface area complicates the analysis

  16. Different effect of scion types on callusing in bench grafting

    use

    2011-10-31

    Oct 31, 2011 ... burst scion, burst cutting-swollen scion, and burst cutting-unburst scion. 21 days after ..... Vol 2: Vegetable, Viticulture, Ornamental. Plants. 4-7 Sept. ... Resonance Imaging Technique (MRI) to investigate graft connection.

  17. Ibrutinib Effective against Graft-Versus-Host Disease

    A Cancer Currents blog post on results from a small clinical trial showing that ibrutinib can effectively treat graft-versus-host-disease, a common and serious complication of allogeneic stem cell transplants.

  18. The graft copolymerisation of acrylamide onto cellulose using ...

    Theobroma cacao) wood meal have been produced using hydroquinone enhanced Fe2+/H2O2 redox system. The addition of hydroquinone to the redox system affected the effectiveness of the redox system to initiate graft copolymer formation.

  19. Managing Above the Graft: How Management Needs its Fertile ...

    Managing Above the Graft: How Management Needs its Fertile Wounds from which ... both captured the imagination of the employees and benefited the core business of a ... The decision was fortuitous, given that the leadership development ...

  20. Punch grafts to treat lower limb intractable sores

    JÚLIO WILSON FERNANDES

    Full Text Available ABSTRACT Lower limb recurrent ulcers, usually caused by prolonged decubitus, trauma, diabetes or burns, may not heal with conventional clinical or surgical treatment. Frequently, laminated skin grafts do not integrate with the recipient layer, and the only alternatives are neighbor microsurgical flaps. These have higher morbidity and create secondary defects, to be corrected with skin grafts, when fasciocutaneous or miocutaneous segments are removed for the treatment of the primary defect. We describe the non-conventional use of punch grafts in the treatment of lower limb ulcers, when conventional skin laminated graft failed, without the use of flaps. Since this is a very successful technique, its use should be considered as a valuable alternative for the treatment of recurrent lower limb ulcers. It is a simple and easy-learned technique that may be used by different surgeons, even in remote places without correct specialized hospital facilities.

  1. Electroosmotic Flow in Mixed Polymer Brush-Grafted Nanochannels

    Qianqian Cao

    2016-12-01

    Full Text Available Mixed polymer brush-grafted nanochannels—where two distinct species of polymers are alternately grafted on the inner surface of nanochannels—are an interesting class of nanostructured hybrid materials. By using a coarse-grained molecular dynamics simulation method, we are able to simulate the electrokinetic transport dynamics of the fluid in such nanochannels as well as the conformational behaviors of the mixed polymer brush. We find that (1 the brush adopts vertically-layered and longitudinally-separated structures due to the coupling of electroosmotic flow (EOF and applied electric field; (2 the solvent quality affects the brush conformations and the transport properties of the EOF; (3 the EOF flux non-monotonically depends on the grafting density, although the EOF velocity in the central region of the channel monotonically depends on the grafting density.

  2. Self-Suspended Suspensions of Covalently Grafted Hairy Nanoparticles

    Choudhury, Snehashis; Agrawal, Akanksha; Kim, Sung A; Archer, Lynden A.

    2015-01-01

    length scales. On mesoscopic length scales, the suspensions display exceptional homogeneity and colloidal stability. We attribute this feature to steric repulsions between grafted chains and the space-filling constraint on the tethered chains

  3. The versatile subepithelial connective tissue graft: a literature update.

    Karthikeyan, B V; Khanna, Divya; Chowdhary, Kamedh Yashawant; Prabhuji, M Lv

    2016-01-01

    Harmony between hard and soft tissue morphologies is essential for form, function, and a good esthetic outlook. Replacement grafts for correction of soft tissue defects around the teeth have become important to periodontal plastic and implant surgical procedures. Among a multitude of surgical techniques and graft materials reported in literature, the subepithelial connective tissue graft (SCTG) has gained wide popularity and acceptance. The purpose of this article is to acquaint clinicians with the current understanding of the versatile SCTG. Key factors associated with graft harvesting as well as applications, limitations, and complications of SCTGs are discussed. This connective tissue has shown excellent short- and long-term stability, is easily available, and is economical to use. The SCTG should be considered as an alternative in all periodontal reconstruction surgeries.

  4. Biphasic calcium phosphate–casein bone graft fortified with Cassia

    Biphasic calcium phosphate; bone graft; Cassia occidentalis; simulated body fluid; SaOS-2 cell line. ... The study investigates the efficacy of CO extract incorporated biphasic calcium phosphate as an osteoinductive material. ... Current Issue

  5. Alveolar cleft closure with iliac bone graft: A case report.

    Tichvy Tammama

    2017-04-01

    Conclusion: The timing of alveolar bone grafting usually associated with the state of the developing of dentition. Post operative management is important to get a good result, and to prevent any complications.

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

    Vanhems, E; Busquet, J

    1975-01-01

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

  7. Open Repair of Mycotic Abdominal Aortic Aneurysms With Biological Grafts

    Heinola, Ivika; Sörelius, Karl; Wyss, Thomas R

    2018-01-01

    BACKGROUND: The treatment of mycotic abdominal aortic aneurysm requires surgery and antimicrobial therapy. Since prosthetic reconstructions carry a considerable risk of reinfection, biological grafts are noteworthy alternatives. The current study evaluated the durability, infection resistance......, and midterm outcome of biological grafts in treatment of mycotic abdominal aortic aneurysm. METHODS AND RESULTS: All patients treated with biological graft in 6 countries between 2006 and 2016 were included. Primary outcome measures were 30- and 90-day survival, treatment-related mortality, and reinfection...... rate. Secondary outcome measures were overall mortality and graft patency. Fifty-six patients (46 males) with median age of 69 years (range 35-85) were included. Sixteen patients were immunocompromised (29%), 24 (43%) had concomitant infection, and 12 (21%) presented with rupture. Bacterial culture...

  8. Grafting study of polysulfone polymeric membranes by gamma ray irradiation

    Furtado Filho, Acacio A.M.; Gomes, Ailton de S.

    2011-01-01

    Radiation-induced grafting of styrene poli sulfone films were investigated by simultaneous method in solution using gamma-ray from a radio nuclide 60 Co source. The gamma-ray energy of high intensity induced breaking of chemical bonds leading to free radical formation. The radical start a conventional polymerization sequence comparable with that obtained with a chemical catalyst acting as initiator. The effects of grafting conditions such as irradiation total dose, dose rate and addition of cross linking agent, were studied by means of morphology analysis, thermal degradation and crystallinity. After the grafting reaction, the membranes were submitted to an exhaustive extraction with solvent to remove the polystyrene homopolymer formed. The degree of grafting (DOG) was analyzed by percentage of weight increase. As a result, the reaction always follows the same pattern: DOG increases rapidly initially whilst propagation is the main reaction, then more slowly as termination becomes more frequent. (author)

  9. Dysphagia after Colon Interposition Graft for Esophageal Carcinoma

    C. Spitali

    2012-01-01

    Full Text Available Colon interposition is an established technique for esophageal reconstruction. We describe the case of primary adenocarcinoma arising in a colonic interposition graft that was performed after total esophagectomy for recurrence adenocarcinoma derived from the Barrett esophagus.

  10. New membranes obtained by grafted irradiated PVDF foils

    Mazzei, R.; García Bermúdez, G.; Camporotondi, D.E.; Arbeitman, C.

    2012-01-01

    The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar + beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid–glycidyl methacrylate (AAc–GMA); acrylic acid–styrene (AAc–S), acrylic acid-N-isopropyl acrylamide (AAc–NIPAAm) and acrylic acid-N-isopropyl acrylamide–glycidyl methacrylate (AAc-NIPAAm–GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

  11. Computerized tomographic evaluation of aortic prosthetic graft complications

    Kay, D.; Kalmar, J.A.

    1985-01-01

    Computerized tomography has been found to be an accurate and sensitive method of diagnosing complications of synthetic aortic grafts. Complications in this series of four cases included aortoesophageal fistula, aortoduodenal fistula, pseudoaneurysm, and retroperitoneal hematoma. 6 references, 5 figures

  12. Tectonic corneal graft for conjunctival rhinosporidiosis with scleral melt

    Pushpa Jacob

    2011-01-01

    Full Text Available A 16 year old girl presented with irritation and watering of the right eye for 3 months. On examination, the superior perilimbal sclera was ectatic with incarcerated uveal tissue covered by conjunctiva. The conjunctiva showed discreet, yellow white mucoid spots. Excision biopsy of the conjunctiva showed subepithelial spherules of sporangia containing numerous endospores, suggestive of rhinosporidiosis. Diathermy was applied to flatten the staphyloma. The ectatic area was covered with a corneal patch graft. The patient was started on prednisolone acetate eye drops and oral dapsone for 6 months. Corneal graft was well incorporated and conjunctivalized by 3 months. Since the graft was not seen within the palpebral aperture, there was good cosmetic result. The corneal graft had the added advantage of transparency which allowed visualization of the underlying tissue to diagnose early recurrence. There was no recurrence at 6 months.

  13. New membranes obtained by grafted irradiated PVDF foils

    Mazzei, R. [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Universidad Tecnologica Nacional Facultad Regional, Buenos Aires (Argentina); Garcia Bermudez, G. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad Nacional de General San Martin, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Camporotondi, D.E., E-mail: camporotondi@cae.cnea.gov.ar [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Arbeitman, C. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); and others

    2012-09-15

    The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar{sup +} beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid-glycidyl methacrylate (AAc-GMA); acrylic acid-styrene (AAc-S), acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid-N-isopropyl acrylamide-glycidyl methacrylate (AAc-NIPAAm-GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

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

    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.

  15. Improving the Outcome of Vein Grafts: Should Vascular Surgeons Turn Veins into Arteries?

    Isaji, Toshihiko; Hashimoto, Takuya; Yamamoto, Kota; Santana, Jeans M.; Yatsula, Bogdan; Hu, Haidi; Bai, Hualong; Jianming, Guo; Kudze, Tambudzai; Nishibe, Toshiya; Dardik, Alan

    2017-01-01

    Autogenous vein grafts remain the gold standard conduit for arterial bypass, particularly for the treatment of critical limb ischemia. Vein graft adaptation to the arterial environment, i.e., adequate dilation and wall thickening, contributes to the superior performance of vein grafts. However, abnormal venous wall remodeling with excessive neointimal hyperplasia commonly causes vein graft failure. Since the PREVENT trials failed to improve vein graft outcomes, new strategies focus on the ada...

  16. Radiographic healing and remodelling of cortical and cancellous bone grafts after rigid plate fixation

    Waris, P.; Karaharju, E.; Slaetis, P.; Paavolainen, P.

    1980-01-01

    Cortical and cancellous interposition grafts, with rigid plate fixation, in the tibiofibular bones of 130 rabbits were followed radiographically for one year. The cancellous grafts healed earlier, but by 12 weeks both graft types had been incorporated, the distal host-graft interface being the last to heal. Progressive cancellous transformation in both the graft and host bone led to an increased over-all bone diameter, a widened medullary canal and a thinned porotic wall. (Auth.)

  17. Multiquadrant Subtenon Triamcinolone Injection for Acute Corneal Graft Rejection: A Case Report

    Sunali Goyal

    2017-05-01

    Full Text Available Background: We report a case of reversal of an acute corneal graft rejection following multiquadrant subtenon triamcinolone injection. Case Presentation: A 19-year-old woman who had acute corneal graft rejection failed to show resolution of the graft rejection after standard treatment with systemic, intravenous, and topical steroids. The graft rejection, however, responded to injection of triamcinolone in multiple subtenon quadrants. Conclusions: For corneal graft rejection, multiquadrant subtenon triamcinolone injections may be a safe adjunct to systemic treatment.

  18. Characterisation of Microbial Cellulose Modified by Graft Copolymerization Technique

    Tita Puspitasari; Cynthia Linaya Radiman

    2008-01-01

    Chemical and phisycal modifications of polymer can be carried out by radiation induced graft copolymerization. This research was carried out to study the morphology and crystallinity of microbial cellulose copolymer grafted by acrylic acid (MC-g-AAC). The SEM microstructural analysis proved that the acrylic acid could diffuse into the microbial celullose and resulted a dense structure. Crystallinity measurement showded that the crystalinity of microbial cellulose increase from 50 % to 53 % after modification. (author)

  19. [Oral mucosa graft urethroplasty for complicated urethral strictures].

    Horiguchi, Akio; Sumitomo, Makoto; Kanbara, Taiki; Tsujita, Yujiro; Yoshii, Takahiko; Yoshii, Hidehiko; Satoh, Akinori; Asakuma, Junichi; Ito, Keiichi; Hayakawa, Masamichi; Asano, Tomohiko

    2010-03-01

    We evaluated the efficacy and outcome of one-stage oral mucosa graft urethroplasty, which is currently the procedure of choice for treating lengthy and complicated urethral strictures not amenable to excision and primary end-to-end anastomosis. Seven patients 33 to 74 years old (mean age = 53.7) underwent one-stage oral mucosa graft urethroplasty for a stricture in either the bulbar urethra (four patients), penile urethra (two patients), or pan-anterior urethra (one patient). Three of the strictures were due to trauma, one was due to inflammation, and one was due to a failed hypospadia repair. The other two were iatrogenic. All patients had previously undergone either internal urethrotomy or repeated urethral dilation. Three patients received a tube graft, three received a ventral onlay, and one received a dorsal onlay. A free graft of oral mucosa was harvested from the inside of each patient's left cheek, and if necessary to obtain a sufficient length, the harvest was extended to include mucosa from the lower lip and the right cheek. The graft lengths ranged from 2.5 to 12 cm (mean = 4.6 cm). A urethral catheter was left in place for 3 weeks postoperatively. While no severe complications at the donor site were observed during follow-up periods ranging from 3 to 55 months (mean = 14 months), two patients who had received a tube graft developed distal anastomotic ring strictures that were managed by internal urethrotomy. The other five required no postoperative urological procedure even though one who had received a ventral onlay developed a penoscrotal fistula. Oral mucosa is an ideal urethral graft, and oral mucosa graft urethroplasty is an effective procedure for repairing complicated urethral strictures involving long portions of the urethra.

  20. 3D-Printed Biodegradable Polymeric Vascular Grafts.

    Melchiorri, A J; Hibino, N; Best, C A; Yi, T; Lee, Y U; Kraynak, C A; Kimerer, L K; Krieger, A; Kim, P; Breuer, C K; Fisher, J P

    2016-02-04

    Congenital heart defect interventions may benefit from the fabrication of patient-specific vascular grafts because of the wide array of anatomies present in children with cardiovascular defects. 3D printing is used to establish a platform for the production of custom vascular grafts, which are biodegradable, mechanically compatible with vascular tissues, and support neotissue formation and growth. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Sap-Sugar Content of Grafted Sugar Maple Trees

    Maurice E. Jr. Demeritt; Maurice E. Jr. Demeritt

    1985-01-01

    In March and April 1983, 289 and 196 young grafted sugar maple trees were tapped and evaluated for sap-sugar content. In April, sap was collected from taps both above and below the graft union. Diameter of all tapped trees at 18 inches above the ground was measured. Analysis of the data revealed that: (1) trees selected for high sugar yield cannot be reproduced by...

  2. Surface modification of polypropylene membrane by polyethylene glycol graft polymerization

    Abednejad, Atiye Sadat, E-mail: atiyeabednejad@gmail.com [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Amoabediny, Ghasem [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 63894-14179, Tehran (Iran, Islamic Republic of); Ghaee, Azadeh [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of)

    2014-09-01

    Polypropylene hollow fiber microporous membranes have been used in a wide range of applications, including blood oxygenator. The hydrophobic feature of the polypropylene surface causes membrane fouling. To minimize fouling, a modification consisting of three steps: surface activation in H{sub 2} and O{sub 2} plasma, membrane immersion in polyethylene glycol (PEG) and plasma graft polymerization was performed. The membranes were characterized by contact angle measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Oxygen transfer of modified membranes was also tested. The stability of grafted PEG was measured in water and in phosphate buffer saline (PBS) at 37 °C. Blood compatibility of modified surfaces was evaluated by the platelet adhesion method. Water contact angel reduction from 110° to 72° demonstrates the enhanced hydrophilicity, and XPS results verify the presence of oxygenated functional groups due to the peak existence in 286 eV as a result of PEG grafting. The results clearly indicate that plasma graft-polymerization of PEG is an effective way for antifouling improvement of polypropylene membranes. Also, the results show that oxygen transfer changes in PEG grafted membranes are not significant. - Highlights: • H{sub 2} and O{sub 2} plasma graft polymerization of PEG on polypropylene membrane was carried out. • Changes in surface properties were investigated by FTIR, XPS, SEM, and AFM. • Surface wettability enhanced as a result of poly ethylene glycol grafting. • PEG grafting degree increase causes reduction of fouling and adhesion.

  3. Application of Biological Tissue Grafts for Burns in Zambia

    Chishimba, Gershom

    2001-01-01

    The author discusses the advances made in the use of Biological Tissue Grafts for the treatment of burns.The paper outlines research activities and clinical trials done in the use of gamma radiation sterilised Amnion membranes and Pig skin grafts in the zambian Heath Care System for treatment of Burns.Ethical issues of Tissue Banking are also discussed in relation to religious and cultural beliefs and Good Manufacturing Practices

  4. Neointima development in externally stented saphenous vein grafts

    Przemysław Węglarz

    2016-11-01

    Full Text Available Introduction : The main limitation of coronary artery bypass grafting (CABG is rapid neointimal hyperplasia leading to graft failure. Aim : To assess plaque formation in saphenous vein grafts (SVG covered by an external Dacron stent in comparison with the classical technique. Material and methods : In the study group vein grafts covered by external stent mesh made of Dacron were implanted. An intravascular ultrasonography (IVUS study was performed in 35 aorto-coronary SVG covered by an external Dacron stent and in 64 normal SVG during the first year after CABG. In each SVG 25 mm of good quality IVUS image, volumes of lumen, plaque (neointima, outer border of the vein graft (external SVG and adventitia were calculated in three time periods: 0–130 days, 130–260 days and 260–390 days. Results : Between the first and second time period, lumen volume (mm3 was reduced from 10.33 ±4.4, to 6.80 ±2.23 in the second period and 5.69 ±1.26 in the third one. This effect was much less marked in normal grafts. The corresponding lumen volume (mm3 was: 10.90 ±3.9, 9.15 ±2.94 and 8.92 ±2.93 in consecutive time periods. Plaque volume (mm3 did not change in control grafts during the course of the study, but it increased very significantly in stented grafts from 0.86 ±1.24 in the first period to 2.70 ±1.58 in the second and 3.29 ±2.66 in the third one. Conclusions : The experimental technique of implanting SVG covered with an external elastic Dacron stent seems to be inferior to traditional ones. This is probably due to the more complicated process of vein implantation and higher micro-injury occurrence during the surgery.

  5. Effect of solubility parameter of monomers on electron beam induced graft-polymerization onto polyethylene films

    Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

    1991-01-01

    Electron beam induced graft-polymerization by the mutual irradiation technique of monomers with different solubility parameters δ onto low density polyethylene films (LDPE) and high density polyethylene films (HDPE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic ratios of surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of monomers, and grafting rates onto LDPE were larger than those onto HDPE. Graft chain contents on surface, which were evaluated in terms of surface tensions and atomic ratios of the surface, increased with increasing δ of monomers, and graft chain contents on surface of HDPE were higher than those of LDPE. It is assumed that mutual solubility of PE and monomers, i.e., infiltration of monomers into PE during graft-polymerization influence grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

  6. Preparation of vinyl acetate grafted natural rubber by irradiation method

    Porntrairat, A.; Pattamaprom, C. [Center of Excellence on Natural Rubber Technology, Department of Chemical Engineering, Faculty of Engineering, Thammasat University, Pathumthani 12120 (Thailand)

    2016-03-09

    Improvement in properties of natural rubber could be done by several methods. In this research, gamma radiation technique, which is simple, accurate, easy to control and clean, was applied to enhance the properties of natural rubber (NR) in latex state. The purpose of this research is to study the appropriate condition for preparing grafted natural rubber latex by using irradiation method. Vinyl acetate monomers (VAc) were grafted onto natural rubber latex (NR-g-PVAc) at 0-10 kGys by gamma radiation from Cobalt-60 source at room temperature. Physical properties of grafted natural rubber such as chloroform number, swelling ratio and gel content were measured. The VAc content of NR-g-PVAc was investigated by titration and visualized by FTIR spectroscopy. The FTIR spectra of NR-g-PVAc prepared at 0-10 kGys showed characteristic peaks of the vinyl acetate confirming that VAc could be grafted onto natural rubber molecular chains effectively under appropriate irradiation conditions. From the result, radiation grafting was found to be a useful technique for grafting of vinyl acetate onto natural rubber.

  7. A dynamical system that describes vein graft adaptation and failure.

    Garbey, Marc; Berceli, Scott A

    2013-11-07

    Adaptation of vein bypass grafts to the mechanical stresses imposed by the arterial circulation is thought to be the primary determinant for lesion development, yet an understanding of how the various forces dictate local wall remodeling is lacking. We develop a dynamical system that summarizes the complex interplay between the mechanical environment and cell/matrix kinetics, ultimately dictating changes in the vein graft architecture. Based on a systematic mapping of the parameter space, three general remodeling response patterns are observed: (1) shear stabilized intimal thickening, (2) tension induced wall thinning and lumen expansion, and (3) tension stabilized wall thickening. Notable is our observation that the integration of multiple feedback mechanisms leads to a variety of non-linear responses that would be unanticipated by an analysis of each system component independently. This dynamic analysis supports the clinical observation that the majority of vein grafts proceed along an adaptive trajectory, where grafts dilate and mildly thicken in response to the increased tension and shear, but a small portion of the grafts demonstrate a maladaptive phenotype, where progressive inward remodeling and accentuated wall thickening lead to graft failure. © 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

  8. Radiation effect on polystyrene deposited and grafted on silica gel

    Kusama, Y.; Udagawa, A.; Takehisa, M.

    1978-01-01

    The effect of radiation on polystyrene was studied in the presence and absence of silica gel by molecular weight measurement with gel permeation chromatography (GPC). Polystyrene crosslinked under vacuum in the absence of silica gel, but it either crosslinked or degraded by radiation, depending on the molecular weight of the polymer in the presence of silica gel. part of the deposited polymer bonded to silica gel by radiation; the G value for graft-chain formation is in the range of 0.01 to 0.1. Irradiation of polystyrene grafted on silica gel resulted in degradation of the graft chain because of the transfer of energy from silica gel. The G value for main chain scission was about 2 when graft polymer was irradiated in the absence of homopolymer. The degradation of graft polymer was suppressed when the polymer was irradiated in the presence of homopolymer, and the amount of unextractable polymer from silica gel increased with increasing irradiation. This adds evidence to the estimation that an increase in grafting percent coupled with a slight decrease in molecular weight at a later stage of radiation-induced polymerization of styrene adsorbed on slica gel is due to a secondary effect of radiation on the polymer

  9. Beta irradiation inhibits neo-intimal formation in vein grafts

    Lang Xiaoou; Ji Shenquan; Zeng Ke; Li Jun; Liu Bingbing; Ma Wenfeng; Zhang Qiang

    2002-01-01

    Objective: The study was to evaluate the effect of beta irradiation on intimal proliferation response in vein grafts. Methods: An autogenous vein graft model was established in 40 rats by transplanting internal branch of jugular vein to carotid artery by end-to-end anastomosis. The vein was irradiated by 32 P before anastomosis. Four dose schedules were studied: (1) control graft (nonirradiated); (2) irradiated with 8 Gy; (3) 18 Gy; and (4) 36 Gy. The grafted veins were harvested at 2 weeks after the operation. IH (intimal hyperplasia) and SMC (smooth muscle cell) proliferation were histologically and immuno-histochemically observed and analyzed by a computer digitalising system. Results: In 18 Gy and 36 Gy-irradiated grafts compared with the control, there was a significant decrease in the average intimal thickness (P 0.05). Immunohistochemical analysis of PCNA indicated decrease of positive cells in both 18 Gy and 36 Gy groups compared with 8 Gy and the control group (P 0.05) groups, and there was also no significant difference between 8 Gy and the control group (P > 0.05). Conclusion: These preliminary results demonstrate that proper dose of beta irradiation in vein graft inhibits smooth muscle cells proliferation and neo-intimal hyperplasia in rat

  10. Defluoridation potential of jute fibers grafted with fatty acyl chain

    Manna, Suvendu; Saha, Prosenjit [Materials Science Centre, IIT Kharagpur, WB 721302 (India); Roy, Debasis, E-mail: debasis@civil.iitkgp.ernet.in [Department of Civil Engineering, IIT Kharagpur, WB 721302 (India); Sen, Ramkrishna [Department of Biotechnology, IIT Kharagpur, WB 721302 (India); Adhikari, Basudam [Materials Science Centre, IIT Kharagpur, WB 721302 (India)

    2015-11-30

    Graphical abstract: - Highlights: • Acyl chain grafted jute has been shown to accumulate fluoride ions. • Covalent and hydrogen bonding and protonation were the contributing factors. • The process is relatively inexpensive and maintenance-free. • Acyl chain grafted jute showed higher fluoride ions accumulation than alternatives. - Abstract: Waterborne fluoride is usually removed from water by coagulation, adsorption, ion exchange, electro dialysis or reverse osmosis. These processes are often effective over narrow pH ranges, release ions considered hazardous to human health or produce large volumes of toxic sludge that are difficult to handle and dispose. Although plant matters have been shown to remove waterborne fluoride, they suffer from poor removal efficiency. Following from the insight that interaction between microbial carbohydrate biopolymers and anionic surfaces is often facilitated by lipids, an attempt has been made to enhance fluoride adsorption efficiency of jute by grafting the lignocellulosic fiber with fatty acyl chains found in vegetable oils. Fluoride removal efficiency of grafted jute was found to be comparable or higher than those of alternative defluoridation processes. Infrared and X-ray photoelectron spectroscopic evidence indicated that hydrogen bonding, protonation and C−F bonding were responsible for fluoride accumulation on grafted jute. Adsorption based on grafted jute fibers appears to be an economical, sustainable and eco-friendly alternative technique for removing waterborne fluoride.

  11. Electrospun polydioxanone-elastin blends: potential for bioresorbable vascular grafts

    Sell, S A [Virginia Commonwealth University, Richmond, VA 23298 (United States); McClure, M J [Virginia Commonwealth University, Richmond, VA 23298 (United States); Barnes, C P [Virginia Commonwealth University, Richmond, VA 23298 (United States); Knapp, D C [Virginia Commonwealth University, Richmond, VA 23298 (United States); Walpoth, B H [University Hospital, 1211 Geneva 14 (Switzerland); Simpson, D G [Virginia Commonwealth University, Richmond, VA 23298 (United States); Bowlin, G L [Virginia Commonwealth University, Richmond, VA 23298 (United States)

    2006-06-15

    An electrospun cardiovascular graft composed of polydioxanone (PDO) and elastin has been designed and fabricated with mechanical properties to more closely match those of native arterial tissue, while remaining conducive to tissue regeneration. PDO was chosen to provide mechanical integrity to the prosthetic, while elastin provides elasticity and bioactivity (to promote regeneration in vitro/in situ). It is the elastic nature of elastin that dominates the low-strain mechanical response of the vessel to blood flow and prevents pulsatile energy from being dissipated as heat. Uniaxial tensile and suture retention tests were performed on the electrospun grafts to demonstrate the similarities of the mechanical properties between the grafts and native vessel. Dynamic compliance measurements produced values that ranged from 1.2 to 5.6%/100 mmHg for a set of three different mean arterial pressures. Results showed the 50:50 ratio to closely mimic the compliance of native femoral artery, while grafts that contained less elastin exceeded the suture retention strength of native vessel. Preliminary cell culture studies showed the elastin-containing grafts to be bioactive as cells migrated through their full thickness within 7 days, but failed to migrate into pure PDO scaffolds. Electrospinning of the PDO and elastin-blended composite into a conduit for use as a small diameter vascular graft has extreme potential and warrants further investigation as it thus far compares favorably to native vessel.

  12. Grafting of gold nanoparticles on polyethyleneterephthalate using dithiol interlayer

    Reznickova, A.; Kolska, Z.; Zaruba, K.; Svorcik, V.

    2014-01-01

    Two different procedures of grafting of polyethyleneterephthalate (PET), modified by plasma treatment, with gold nanoparticles (nanospheres) are studied. In the first procedure the PET foil was grafted with biphenyl-4,4′-dithiol and subsequently with gold nanoparticles. In the second one the PET foil was grafted with gold nanoparticles previously coated by the same dithiol. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and electrokinetic analysis were used for characterization of the polymer surface at different modification steps. Gold nanoparticles were characterized by ultraviolet–visible spectroscopy. The first procedure was found to be more effective. It was proved that the dithiol was chemically bonded to the surface of the plasma activated PET and it mediates subsequent grafting of the gold nanoparticles. - Highlights: • Two different techniques were used for coating of PET with gold nanoparticles. • Grafted GNPs were characterized by XPS, FTIR, UV–vis, zeta potential, AFM. • More effective coating is achieved by deposition of GNPs earlier grafted with thiol. • The studied structures may have potential application in electronics or biomedicine

  13. Scarless abdominal fat graft harvest for neurosurgical procedures: technical note.

    Trinh, Victoria T; Duckworth, Edward A M

    2015-02-01

    Background Abdominal fat grafts are often harvested for use in skull base reconstruction and cerebrospinal fluid (CSF) leak repairs, and for operations traversing the nasal sinuses or mastoid bone. Although the endoscopic transnasal surgery has gained significant popularity, in part because it is considered "scarless," a common adjunct, the abdominal fat graft, can result in a disfiguring scar across the abdomen. Objective This is the first report of a scarless abdominal fat graft technique for skull base reconstruction. Methods Ten patients with a median age of 56.5 years (range: 45-73 years) underwent endoscopic transsphenoidal tumor resection with intraumbilical fat graft harvest. Careful circumferential fat dissection at the umbilicus, with progressive retraction of the graft, was crucial to ensure maximal visualization and to prevent injury to the subcutaneous vessels and rectus fascia. Results Following reconstruction of the sellar skull base, all patients did well postoperatively with no evidence of CSF leak. At 12-week follow-up for all patients, there was no evidence of scar, intracavity hematoma, or wound infection. Conclusions Fat graft harvest through an intraumbilical incision results in a scar-free abdominal harvest, and is a useful procedural adjunct to complement "scarless" brain surgery.

  14. Calculations for reproducible autologous skin cell-spray grafting.

    Esteban-Vives, Roger; Young, Matthew T; Zhu, Toby; Beiriger, Justin; Pekor, Chris; Ziembicki, Jenny; Corcos, Alain; Rubin, Peter; Gerlach, Jörg C

    2016-12-01

    Non-cultured, autologous cell-spray grafting is an alternative to mesh grafting for larger partial- and deep partial-thickness burn wounds. The treatment uses a suspension of isolated cells, from a patient's donor site skin tissue, and cell-spray deposition onto the wound that facilitates re-epithelialization. Existing protocols for therapeutic autologous skin cell isolation and cell-spray grafting have defined the donor site area to treatment area ratio of 1:80, substantially exceeding the coverage of conventional mesh grafting. However, ratios of 1:100 are possible by maximizing the wound treatment area with harvested cells from a given donor site skin tissue according to a given burn area. Although cell isolation methods are very well described in the literature, a rational approach addressing critical aspects of these techniques are of interest in planning clinical study protocols. We considered in an experimental study the cell yield as a function of the donor site skin tissue, the cell density for spray grafting, the liquid spray volume, the sprayed distribution area, and the percentage of surface coverage. The experimental data was then used for the development of constants and mathematical equations to give a rationale for the cell isolation and cell-spray grafting processes and in planning for clinical studies. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  15. The Impact of Liver Graft Injury on Cancer Recurrence Posttransplantation.

    Li, Chang-Xian; Man, Kwan; Lo, Chung-Mau

    2017-11-01

    Liver transplantation is the most effective treatment for selected patients with hepatocellular carcinoma. However, cancer recurrence, posttransplantation, remains to be the critical issue that affects the long-term outcome of hepatocellular carcinoma recipients. In addition to tumor biology itself, increasing evidence demonstrates that acute-phase liver graft injury is a result of hepatic ischemia reperfusion injury (which is an inevitable consequence during liver transplantation) and may promote cancer recurrence at late phase posttransplantation. The liver grafts from living donors, donors after cardiac death, and steatotic donors have been considered as promising sources of organs for liver transplantation and are associated with high incidence of liver graft injury. The acute-phase liver graft injury will trigger a series of inflammatory cascades, which may not only activate the cell signaling pathways regulating the tumor cell invasion and migration but also mobilize the circulating progenitor and immune cells to facilitate tumor recurrence and metastasis. The injured liver graft may also provide the favorable microenvironment for tumor cell growth, migration, and invasion through the disturbance of microcirculatory barrier function, induction of hypoxia and angiogenesis. This review aims to summarize the latest findings about the role and mechanisms of liver graft injury resulted from hepatic ischemia reperfusion injury on tumor recurrence posttransplantation, both in clinical and animal cohorts.

  16. Pasteurized intercalary autogenous bone graft: radiographic and scintigraphic features

    Ehara, Shigeru; Tamakawa, Yoshiharu; Nishida, Jun; Shiraishi, Hideo

    2000-01-01

    Objective. Pasteurized autogenous bone graft sterilized at a low temperature (60 C) is one option for reconstruction after resection of bone and soft tissue tumors. The purpose of this investigation was to assess the normal and abnormal radiographic and scintigraphic findings of pasteurized intercalary autogenous bone graft after resection of bone and soft tissue sarcomas.Design. This was a retrospective evaluation of the radiography and bone scintigraphy findings in patients after treatment of bone and soft tissue sarcomas using an intercalary pasteurized autogenous bone graft.Patients. Among 10 consecutive patients, eight had intercalary grafts, and they constitute the subjects of this study. All available radiography and bone scintigraphy findings were reviewed for the healing process and the possibility of complications.Results and conclusions. Healing and incorporation of the graft were observed in five patients during the follow-up, but the other three did not heal satisfactorily. Rapid incorporation of pasteurized autogenous bone graft can be demonstrated by means of radiography and bone scintigraphy. (orig.)

  17. Additives in UV and ionising radiation grafting and curing processes

    Garnett, J.L.; Ng, L.T.; Viengkhou, V.

    1998-01-01

    Full text: Curing of polymers induced by both UV and ionising radiation are now established technologies. Currently both systems are predominantly based on acrylate chemistry. UV processes use photoinitiators to achieve fast polymerisation. In the proposed paper the significance of the occurrence of concurrent grafting with cure will be examined. particularly with respect to the recycling of finished product. Basic studies on grafting initiated by UV and ionising radiation will be discussed. Polar methyl methacrylate (MMA) and non-polar styrene will be used as representative monomers with cellulose and propylene typifying the backbone polymers. The additives chosen for examination in this study are predominantly components used in radiation curing formulations since grafting and curing are known to be mechanically related. The additives used were mineral acid, photoinitiators, vinyl ethers, oligomers, polyfunctional monomers including multifunctional acrylates (MFAs) and methacrylates (MFMAs). For the first time the use of charge transfer complexes in the Mulliken sense as additives in radiation grafting will be discussed. The CT complexes themselves, being monomers, have also been grafted to the above polymers. Recent developments with excimer laser sources for initiating these processes will be discussed, especially the use of non-acrylate chemistry. Excimer laser sources are shown to complement conventional UV and ionising radiation and are photoinitiator free. Mechanisms for the above grafting and curing processes will be outlined

  18. Autologous fat grafting: use of closed syringe microcannula system for enhanced autologous structural grafting

    Alexander RW

    2013-04-01

    Full Text Available Robert W Alexander,1 David Harrell2 1Department of Surgery, School of Medicine and Dentistry, University of Washington, Seattle, WA, USA; 2Harvest-Terumo Inc, Plymouth, MA, USA Objectives: Provide background for use of acquiring autologous adipose tissue as a tissue graft and source of adult progenitor cells for use in cosmetic plastic surgery. Discuss the background and mechanisms of action of closed syringe vacuum lipoaspiration, with emphasis on accessing adipose-derived mesenchymal/stromal cells and the stromal vascular fraction (SVF for use in aesthetic, structural reconstruction and regenerative applications. Explain a proven protocol for acquiring high-quality autologous fat grafts (AFG with use of disposable, microcannula systems. Design: Explain the components and advantage of use of the patented super luer-lock and microcannulas system for use with the closed-syringe system. A sequential explanation of equipment selection for minimally traumatic lipoaspiration in small volumes is presented, including use of blunt injection cannulas to reduce risk of embolism. Results: Thousands of AFG have proven safe and efficacious for lipoaspiration techniques for large and small structural fat grafting procedures. The importance and advantages of gentle harvesting of the adipose tissue complex has become very clear in the past 5 years. The closed-syringe system offers a minimally invasive, gentle system with which to mobilize subdermal fat tissues in a suspension form. Resulting total nuclear counting of undifferentiated cells of the adipose-derived -SVF suggests that the yield achieved is better than use of always-on, constant mechanical pump applied vacuum systems. Conclusion: Use of a closed-syringe lipoaspiration system featuring disposable microcannulas offers a safe and effective means of harvesting small volumes of nonmanipulated adipose tissues and its accompanying progenitor cells within the SVF. Closed syringes and microcannulas are

  19. GRAFT VERSUS HOST DISEASE- ORAL PRESENTATION

    Pradeep P. S

    2017-09-01

    Full Text Available BACKGROUND Graft-versus-host disease (GVHD is described as a potentially life-threatening complication caused by allogeneic haematopoietic cell transplantation. It is an exaggerated manifestation of a normal inflammatory mechanism in which donor lymphocytes encounter foreign antigens in an atmosphere that promote inflammation. 90% of the patients show oral features in case of cGVHD. Oral mucosal lesions and salivary gland dysfunction are the main oral features of chronic GVHD. Trismus or reduction of the mouth opening due to the perioral deposition of collagen is also commonly seen. Purpose of this review is to understand pathophysiology of oral presentations of GVHD. MATERIALS AND METHODS Review related to GVHD pathophysiology, oral lesions after haematopoietic cell transplant encompassed literature from 1966 through 2015. Review of Medline/PubMed Journals were done. RESULTS It is difficult to describe the pathophysiology of oral manifestations because there is no well accepted definition. CONCLUSION Larger well-designed clinical studies are needed to understand the pathobiology of oral cGVHD and determine best treatments for this disease.

  20. Preparation of Dimethylaminoethylmethacrylate Grafted Polymeric Adsorbent by Using Radiation-Induced Grafting Technique for Removal of Anions

    Kavakli, P. A.

    2006-01-01

    The development of efficient separation and purification techniques is very important from industrial, environmental and economic points of view. Polymeric materials having polyfunctional groups such as carboxylic, amide, nitrile, iminodiacetic acid, amidoxime, and ammonium groups, etc., not only possess good hydrophilic properties, but also have good ion exchange properties which make them suitable for metal recovery from aqueous solutions. Radiation induced grafting is a powerful technique capable of controlling the introduction of various functional groups to the polymeric materials, keeping the original properties and especially the mechanical strength of the base material, and thus, allowing the synthesis of more stable polymeric adsorbents. The main objective of this study was to develop special polymeric adsorbents to remove NOx and PO 4 anions from aqueous systems. For this purpose, a novel nonwoven fabric was prepared by radiation-induced graft polymerization of imethylaminoethylmethacrylate (DMAEMA) onto polypropylene coated polyethylene nonwoven fabric. The trunk polymer was irradiated by electron beam at a voltage of 2 MeV and a current of 3 mA in a nitrogen atmosphere at dry-ice temperature at different doses. The degree of grafting was determined as a function of the total dose, monomer concentration, temperature, and reaction time. It was found that the degree of grafting of grafted polymer was greatly affected by reaction conditions. Grafting conditions were optimized, and about 150 % degree of grafting samples was used for further experiments. DMAEMA grafted polymer was later protonated by using acid solution to prepare adsorbent for the removal of anions. Adsorption experiments were performed in column mode for removal of phosphate. Approximately 2000 bed volumes of phosphate-free water can be produced from 10 ppb phosphate solution at high space velocity

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

    Tobella-Camps, María L.; Rivera-Baró, Alejandro

    2014-01-01

    Introduction: Alveolar bone grafting is a vital part of the rehabilitation of cleft patients. The factors that have been most frequently associated with the success of the graft are the age at grafting and the pre-grafting orthodontic treatment. Objectives: 1) Describe the cases of alveolar bone grafts performed at the Maxilofacial Unit of Hospital Sant Joan de Déu, Barcelona (HSJD); and 2) Analyze the success/failure of alveolar grafts and related variables. Material and Methods: Descriptive retrospective study using a sample of 104 patients who underwent a secondary alveolar graft at the Craniofacial Unit of HSJD between 1998 and 2012. The graft was done by the same surgeon in all patients using bone from the iliac crest. Results: 70% of the patients underwent the procedure before the age of 15 (median 14.45 years); 70% of the graft patients underwent pre-graft maxillary expansion. A total of 100 cases were recorded as successful (median age of 14.58 years, 68 underwent pre-graft expansion) and only 4 were recorded as failures (median age of 17.62 years, 3 underwent pre-graft expansion). We did not find statistically significant differences in age at the time of grafting or pre-surgical expansion when comparing the success and failure groups. We found the success rate of the graft to be 96.2%. Conclusions: The number of failures was too small to establish a statistically significant conclusion in our sample regarding the age at grafting and pre-grafting expansion. The use of alveolar bone grafting from the iliac crest has a very high success rate with a very low incidence of complications. Existing controversies regarding secondary bone grafting and the wide range of success rates found in the literature suggest that it is necessary to establish a specific treatment protocol that ensures the success of this procedure. Key words:Alveolar graft, cleft lip and palate, alveolar cleft, alveolar defect. PMID:24880440

  2. Synthesis of Radiation Grafted Polymer Matrices for Separation and Industrial Applications

    Bhardwaj, Y K; Virendra, K; Goel, N K; Sarma, K S.S.; Sabharwal, S [Radiation Technology Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

    2012-09-15

    Grafting of acrylonitrile onto non-woven porous polypropylene fibre sheet using electron beam was carried out by post-irradiation grafting. Grafting extent of {approx}125% was achieved. The grafted nitrile groups were amidoximated and studied for uranium uptake from sea water and heavy metal ions (Co{sup 2+}, Ni{sup 2+}, Mn{sup 2+}, and Cd{sup 2+}) from aqueous solutions. Adsorption and elution of adsorbed ions in suitable eluents was studied. The grafting process was upgraded to pilot scale to obtain 1x1 m{sup 2} sheets. Mutual radiation grafting technique was used for grafting of vinylbenzyltrimethyl ammonium chloride, [2- (methacryloyloxy)ethyl] trimethylammonium chloride and [2-(acryloyloxyethyl)]trimethylammonium chloride onto cotton cellulose substrate. The grafted matrices showed significantly higher water uptake and good water retention properties. The antibacterial efficacy of the grafted products was found to be a function of extent of grafting and the type of bacteria (Escherichia coli, Pseudomonas flourescens, Staphylococcus aureus and Bacillus cereus). PVBT-g-cotton was studied for its protein adsorption behaviour in continuous column process using Bovine serum albumin (BSA) as a model protein. Mutual radiation grafting technique was used to graft acrylic acid on micrometer thick micro-porous polypropylene membrane. Contact angle measurement studies showed that initial grafting as well as radiation treatment of poly(propylene) in aqueous medium and in presence of Mohr's salt enhances its affinity towards the grafting solution. The enhancement in the polar component of surface energy of treated polypropylene membrane is the primary cause of grafting enhancement. The membranes grafted to an extent of {approx}20% were found to perform comparably with the battery separator presently being used by battery industry. Acrylic acid was grafted to Teflon scrap by mutual radiation grafting technique. The grafting extent decreased with increasing dose rate and

  3. Surface Modifications of Polymers Induced by Heavy Ions Grafting

    Mazzei, R O; Lombardo, J; Camporotondi, D; Tadey, D; Bermudez, G G [National Atomic Energy Commission, Ezeiza Atomic Centre, Ezeiza (Argentina)

    2012-09-15

    Polymer surfaces are modified by the application of swift heavy ions etching and grafting procedures. The residual active sites produced by heavy ion beams, remaining after the etching process, were used to start the grafting process. In order to produce tracks on foils of poly(vinylidene fluoride) (PVDF) they were irradiated with {sup 208}Pb of 25.62 MeV/n or with 115 MeV Cl ions. Moreover, foils of polypropylene (PP) were irradiated with {sup 208}Pb of 25.62 MeV/n. Then, they were etched and grafted with N-isopropylacrylamide (NIPAAm) monomers or with acrylic acid (AAc) monomers, respectively. The replica method allowed the observation of the shape of the grafted tracks using transmission electron microscopy (TEM). In addition NIPAAm grafted foils were analyzed using Fourier transform infrared spectroscopy (FTIR). The sulfonation procedure (methodology previously described for perfluorated polymers) was applied on grafted PVDF. A new method is described to produce a thin layer of poly-acrylic-acid (membranes) that grows on the surface of PVDF foils implanted by an Ar{sup +} beam with energies between 30-150 keV. Different combinations of monomers in water solutions were used such as: acrylic acid (AAc); acrylic acid-glycidyl methacrylate (AAc-GMA); acrylic acid-styrene (AAc-S); acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid-N-isopropyl acrylamide - glycidyl methacrylate (AAc-NIPAAm-GMA). The experimental results show that for particular values of: ion fluence and energy, AAc concentration, sulphuric acid and PVDF polymorphous (alpha or beta) a huge percentage of grafting was obtained. At certain point of the grafting process the development of the PolyAAc-Xmonomer produce a detachment from the irradiated substrate and continue its grafting outside it. This method produces a membrane that is an increased replica of the original implanted surface. Finally, PVDF films implanted by an Ar{sup +} beam with energies about 100 keV and a fluence of 10

  4. Modeling conduction in host-graft interactions between stem cell grafts and cardiomyocytes.

    Chen, Michael Q; Yu, Jin; Whittington, R Hollis; Wu, Joseph C; Kovacs, Gregory T A; Giovangrandi, Laurent

    2009-01-01

    Cell therapy has recently made great strides towards aiding heart failure. However, while transplanted cells may electromechanically integrate into host tissue, there may not be a uniform propagation of a depolarization wave between the heterogeneous tissue boundaries. A model using microelectrode array technology that maps the electrical interactions between host and graft tissues in co-culture is presented and sheds light on the effects of having a mismatch of conduction properties at the boundary. Skeletal myoblasts co-cultured with cardiomyocytes demonstrated that conduction velocity significantly decreases at the boundary despite electromechanical coupling. In an attempt to improve the uniformity of conduction with host cells, differentiating human embryonic stem cells (hESC) were used in co-culture. Over the course of four to seven days, synchronous electrical activity was observed at the hESC boundary, implying differentiation and integration. Activity did not extend far past the boundary, and conduction velocity was significantly greater than that of the host tissue, implying the need for other external measures to properly match the conduction properties between host and graft tissue.

  5. Study on grafting of different types of acrylic monomers onto natural rubber by γ-rays

    Dafader, N.C.; Haque, M.E.; Akhtar, F.; Ahmad, M.U.

    2006-01-01

    A comparative study of various acrylic monomers for grafting onto natural rubber was done. The stability of natural rubber latex (NRL) against coagulum with monomer, mechanical properties of grafted rubbers and percent of grafting were investigated. The NRL with monomers, methylacrylate (MA), ethylacrylate (EA) and n-butylacrylate (n-BA), is unstable but it is stable with methyl methacrylate (MMA), n-butyl methacrylate (BMA) and cyclohexyl methacrylate (CHMA). The mechanical properties and degree of grafting attained a maximum at a total radiation dose of 4 kGy. The values of tensile properties of MMA and CHMA grafted rubbers are almost similar, and higher than those of BMA grafted rubbers. On the other hand, the degree of grafting for CHMA is higher than those of MMA and BMA grafted rubbers. The infrared (IR) spectra of monomer grafted natural rubber were also studied

  6. Electrolytic membrane formation of fluoroalkyl polymer using a UV-radiation-based grafting technique and sulfonation

    Shironita, Sayoko; Mizoguchi, Satoko; Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188, Niigata (Japan)

    2011-03-15

    A sulfonated fluoroalkyl graft polymer (FGP) membrane was prepared as a polymer electrolyte. First, the FGP membrane was grafted with styrene under UV irradiation. The grafted FGP was then sulfonated to functionalize it for proton conductivity. The grafting degree of the membrane increased with increasing grafting time during UV irradiation. The proton conductivity of the membrane increased with increasing grafting degree. The swelling ratio was independent of the grafting time, however, the water uptake increased with increasing grafting degree. Based on these results, it was found that the UV-initiated styrene grafting occurred along the membrane thickness direction. Moreover, the membrane was embedded within the glass fibers of the composite. This composite electrolytic membrane had 1.15 times the proton conductivity of a Nafion 117 membrane.

  7. Hydrophilicity improvement of polyethersulfone powders by grafting acrylic acid with γ-ray simultaneous irradiation method

    Deng Bo; Hou Zhengchi; Zhang Fengying; Xie Leidong; Li Jing; Yang Haijun

    2005-01-01

    Acrylic acid was grafted to Polyethersulfone (PES) powders by liquid-phase simultaneous irradiation. Effects of grafting conditions, such as absorbed dose, volume fraction of monomer, inhibitor (Cu 2+ ) concentration, and pH of the grafting solution on degree of the grafting were investigated. Combined with gravimetric analysis, a working curve of grafting degree through FT-IR quantitative analysis was obtained. The highest grafting degree was achieved at dose of 25 kGy, volume fraction of monomer of 30% and inhibitor concentration of 0.004 mol/L. Greater degrees of the grafting could be obtained by adding increasing amount of hydrochloric acid to the system. Hydrophilicity of the grafted PES powders increased with higher degrees of the grafting. (authors)

  8. Analysis of polymer grafted inside the porous hydrogel using confocal laser scanning microscopy

    2007-04-01

    Full Text Available Graft polymerization of glycidyl methacrylate onto the pore surface of polyacrylamide macroporous gel was implemented in DMSO-aqueous solution using diperiodatocuprate(III complexes as an initiator. The grafting densities up to 410% were achieved. The graft polymerization was confirmed by gravimetrical methods and FTIR. The graft polymerization of polymer inside the pores of the macroporous gel resulted in increased flow resistance through the gel matrix. The distribution of grafted polymer on the gel pore surface material was studied by scanning electron microscopy (SEM and confocal laser scanning microscopy (CLSM. CLSM is an alternative method for studying morphology of gel surface with grafted polymer having the advantages over the SEM allowing to investigate the distribution of grafted polymer inside the hydrogel in a native hydrated state. The microscopic techniques demonstrated uneven distribution of the grafted polymer inside the gel pores as a result of initiating the graft polymerization by insoluble initiator deposited on the pore surface.

  9. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    Liu Hanzhou; Yu Ming; Deng Bo; Li Linfan; Jiang Haiqing; Li Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA). - Highlights: → Acrylonitrile is grafted onto pre-irradiated polyethylene (PE) nonwoven fabrics. → Emulsion system is applied, for the graft polymerization avoids organic solvent. → Kinetic of the pre-irradiation induced graft polymerization is studied. → Optimal condition is determined at the temperature below the b.p. of acrylonitrile.

  10. Polymeric flocculant based on cassava starch grafted polydiallyldimethylammonium chloride: Flocculation behavior and mechanism

    Razali, M.A.A.; Ariffin, A., E-mail: srazlan@usm.my

    2015-10-01

    Graphical abstract: - Highlights: • Flocculation performance of cassava grafted polyDADMAC was studied. • Turbidity and TSS removal increased with increasing grafting percentage. • The grafted polymer showed good removal in acidic and neutral region. • Zeta potential results pointed to the charge neutralization mechanism. • Flocs increased with increasing grafting percentage and molecular weight. - Abstract: In this work, flocculation properties of cassava starch grafted polydiallyldimethylammonium chloride (polyDADMAC) with different grafting percentages were investigated. Flocculation performance was evaluated in simulated kaolin suspension. The grafting percentages used were 1.76 %, 14.84 %, and 21.98 %. The effectiveness of the flocculation was measured based on the reduction of the turbidity and total suspended solids (TSSs), zeta potential measurements, particle size, and atomic force microscopy imaging. Grafted polymers improved the removal rate of turbidity and TSS compared with gelatinized starch, and the removal rate increased with increasing grafting percentage and dosage.

  11. Optimization of process parameter for graft copolymerization of glycidyl methacrylate onto delignified banana fibers

    Selambakkannu, S.; Nor Azillah Fatimah Othman; Siti Fatahiyah Mohamad

    2016-01-01

    This paper focused on pre-treated banana fibers as a trunk polymer for optimization of radiation-induced graft copolymerization process parameters. Pre-treated banana fiber was grafted with glycidyl methacrylate (GMA) via electron beam irradiation. Optimization of grafting parameters in term of grafting yield was analyzed at numerous radiation dose, monomer concentration and reaction time. Grafting yield had been calculated gravimetrically against all the process parameters. The grafting yield at 40 kGy had increases from 14 % to 22.5 % at 1 h and 24 h of reaction time respectively. Grafting yield at 1 % of GMA was about 58 % and it increases to 187 % at 3 % GMA. The grafting of GMA onto pre-treated banana fibers confirmed with the characterization using FTIR, SEM and TGA. Grafting of GMA onto pre-treated fibers was successfully carried out and it was confirmed by the results obtained via the characterization. (author)

  12. Study of maleic anhydride and styrene grafted onto polypropylene induced by UV irradiation

    Li Zhenzhong; He Wei; Guo Hongjun; Zhang Wenxiong; Ma Yalin

    2007-01-01

    Maleic anhydride (MAH) and styrene (St) grafted onto polypropylene (PP) were prepared by UV irradiation. Effects of the irradiation time, monomer and initiator content on the grafting rate and melt flow rate (MFR) were studied. The results show that the optimal duration of UV irradiation is 30s. The grafting rate increases with initiator content when initiator content less than 0.6 phr, the MFR value of grafted PP reaches the highest point when benzophenone (BP) content is 0.4 phr. The content of MAH and St have an effect on the grafting rate and MFR value of the grafted PP, and the optimal contents of monomer is 4 phr. The existence of St as a comonomer reduces apparently the MFR value of grafted PP greatly. Grafted PP present significant changes in crystallization and fusion peaks, indicating differences in crystal size and formation after grafting reaction. (authors)

  13. Polymeric flocculant based on cassava starch grafted polydiallyldimethylammonium chloride: Flocculation behavior and mechanism

    Razali, M.A.A.; Ariffin, A.

    2015-01-01

    Graphical abstract: - Highlights: • Flocculation performance of cassava grafted polyDADMAC was studied. • Turbidity and TSS removal increased with increasing grafting percentage. • The grafted polymer showed good removal in acidic and neutral region. • Zeta potential results pointed to the charge neutralization mechanism. • Flocs increased with increasing grafting percentage and molecular weight. - Abstract: In this work, flocculation properties of cassava starch grafted polydiallyldimethylammonium chloride (polyDADMAC) with different grafting percentages were investigated. Flocculation performance was evaluated in simulated kaolin suspension. The grafting percentages used were 1.76 %, 14.84 %, and 21.98 %. The effectiveness of the flocculation was measured based on the reduction of the turbidity and total suspended solids (TSSs), zeta potential measurements, particle size, and atomic force microscopy imaging. Grafted polymers improved the removal rate of turbidity and TSS compared with gelatinized starch, and the removal rate increased with increasing grafting percentage and dosage

  14. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  15. Noninvasive detection of coronary artery bypass graft patency by intravenous electron beam computed tomographic angiography.

    Yamakami, Shoji; Toyama, Junji; Okamoto, Mitsuhiro; Matsushita, Toyoaki; Murakami, Yoshimasa; Ogata, Masaki; Ito, Shigenori; Fukutomi, Tatsuya; Okayama, Naotsuka; Itoh, Makoto

    2003-11-01

    This study evaluates the usefullness of intravenous electron beam computed tomographic angiography (EBA) for the detection of coronary artery bypass graft patency in 43 patients (33 men and 10 women, mean age, 65 years) who had coronary artery bypass graft surgery. EBA was performed a few days before selective bypass graft angiography (SGA). Forty axial cross-sections of angiographic images of the heart were acquired consecutively by an electrocardiographic trigger signal at 40% of the RR interval, which corresponds to the end-systolic phase. EBA data were reconstructed as a three-dimensional shaded surface display of the heart and bypass grafts. Detectability of the patency of bypass gratis was evaluated, taking selective angiographic images of the bypass grafts as a gold standard. One hundred and nine grafts (96%) out of 114 grafts were subjected to evaluation: 37 grafts were left internal mammary artery grafts (LIMA), 7 were right internal mammary artery grafts (RIMA), 6 were gastroepiploic artery grafts (GEA), 7 were free gastroepiploic artery grafts with venous drainage (free-GEA), 7 were radial artery grafts (RAG), and 45 were saphenous vein gratis (SVG). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBA were 98%, 100%, 100%, 91%, and 98%, respectively. EBA sampled at the end-systolic period was determined to be useful for the detection of coronary artery bypass graft patency and occlusion.

  16. Using negative pressure therapy for improving skin graft taking on genital area defects following Fournier gangrene.

    Orhan, Erkan; Şenen, Dilek

    2017-09-01

    Fournier's gangrene is an infective necrotizing fasciitis of the perineal, genital and perianal regions. Treatment includes aggressive surgical debridement that often results in extensive loss of genital skin. Skin grafts may be used for reconstruction but skin grafting of the male genitalia is diffucult because the penis and scrotum are mobile and deformable. A variety of methods are used to secure skin graft to recipient beds. We used negative pressure therapy (NPT) to secure skin grafts and improve skin graft taking. We used negative pressure therapy for graft fixation in 13 male patients who underwent debridements with the indication of Fournier gangrene, and whose defects formed were reconstructed with grafts between January 2009, and January 2014. Information about age of the patients, sessions of negative pressure therapy applied before, and after reconstruction, duration of hospital stay, and graft losses during postoperative period were recorded. Median age of the patients was 56.15 (46-72) years. NPT was applied to patients for an average of 6.64 sessions (4-12) before and 1 sessions after graft reconstruction. Patients were hospitalized for an average of 26.7 (20-39) days. Any graft loss was not seen after NPT. Because of the peculiar anatomy of the genital region, anchoring of grafts is difficult so graft losses are often encountered. Use of NPT for ensuring graft fixation on the genital region prevents skin graft shearing.

  17. Radioinduced grafting of acrylic acid on expanded polystyrene matrices

    Postolache, C.; Simion, Corina; Dragomir, A.; Ponta, C.; Chirvasoiu, G.; Postolache, Carmen

    1998-01-01

    The unfixed surface radioactive contamination for low energy β radionuclides ( 3 H and 14 C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm 3 . The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO 4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60 Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3 H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

  18. Delayed allogeneic skin graft rejection in CD26-deficient mice.

    Zhao, Xiangli; Zhang, Kai; Daniel, Peter; Wisbrun, Natali; Fuchs, Hendrik; Fan, Hua

    2018-03-23

    Organ transplantation is an effective therapeutic tool for treating many terminal diseases. However, one of the biggest challenges of transplantation is determining how to achieve the long-term survival of the allogeneic or xenogeneic transplant by, for example, preventing transplant rejection. In the current study, CD26 gene-knockout mice were used to investigate the potential role of CD26/dipeptidyl peptidase-4 (DPPIV) in allogeneic skin graft rejection by tail-skin transplantation. Compared with wild-type (CD26 +/+ ) counterparts, CD26 -/- mice showed reduced necrosis of grafts and delayed graft rejection after skin transplantation. Concentrations of serum IgG, including its subclasses IgG1 and IgG2a, were significantly reduced in CD26 -/- mice during graft rejection. Moreover, after allogeneic skin transplantation, the secretion levels of the cytokines IFN-γ, IL-2, IL-6, IL-4, and IL-13 were significantly reduced, whereas the level of the cytokine IL-10 was increased in the serum of CD26 -/- mice compared with that in the serum of CD26 +/+ mice. Additionally, the concentration of IL-17 in serum and the percentage of cells secreting IL-17 in mouse peripheral blood lymphocytes (MPBLs) were both significantly lower, while the percentage of regulatory T cells (Tregs) was significantly higher in MPBLs of CD26 -/- mice than in those of CD26 +/+ mice. Furthermore, a lower percentage of CD8 + T cells in MPBLs and fewer infiltrated macrophages and T cells in graft tissues of CD26 -/- mice were detected during graft rejection. These results indicate that CD26 is involved in allogeneic skin graft rejection and provides another hint that CD26 deficiency leads to less rejection due to lower activation and proliferation of host immune cells.

  19. Surface functionalization of cellulose by grafting oligoether chains

    Ly, El hadji Babacar; Bras, Julien; Sadocco, Patrizia; Belgacem, Mohamed Naceur; Dufresne, Alain; Thielemans, Wim

    2010-01-01

    Two cellulosic substrates (Whatman paper and wood fibres) were chemically modified using different oligoether chains; poly(ethylene) (POE), poly(propylene) (PPG) and poly(tetrahydrofuran) (PTHF) glycols with different lengths were first converted into mono-NCO-terminating macromolecules to allow direct grafting to the cellulose substrates. This step was achieved by reacting the chosen oligoether with 2,4-toluene diisocyanate. The prepared macromolecular grafts were then coupled with the cellulose surface and the resulting treated substrates were fully characterized by contact angle measurements, elemental analysis, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Thus, all the techniques implemented showed clear evidence of successful grafting, namely: (i) when using PPG grafts, the polar contribution to the surface energy decreased from approximately 25 to virtually 0 mJ m -2 and the wettability by water decreased, as the water contact angle shifted from around 40 to above 90 o ; (ii) nitrogen atoms were detected by elemental analysis and XPS; (iii) the aliphatic carbon contents increased from 11 to about 39-50%, depending on the oligoether used; and (iv) small spheres having about 100 nm diameter were detected by SEM. Moreover, the grafted fibres were submitted to biodegradation tests which showed that they conserved their biodegradable character, although with a slower biodegradation rate. The novelty of the present paper is the direct grafting of the polymeric matrix onto the fibre surface thanks to a new modification strategy involving the use of a diisocyanate as a mediator between the matrix and the reinforcing elements. The covalently linked polymeric chains constituting the matrix could melt under heating, thus, yielding the interdiffusion of the macromolecular grafts and forming the composite.

  20. Synthesis and properties of silane-fluoroacrylate grafted starch.

    Qu, Jia; He, Ling

    2013-10-15

    The latex of silane-fluoroacrylate grafted starch for coating materials, VTMS-starch/P(MMA/BA/3FMA), is obtained by two step grafting reactions. Vinyltrimethoxysilane (VTMS) is primarily grafted onto starch by condensation between Si-OH and C-OH at 120 °C, and then the copolymer of methyl methacrylate (MMA), butyl acrylate (BA) and 2,2,2-trifluoroethyl methacrylate (3FMA) is grafted onto the VTMS-starch by emulsion polymerization. Fourier transform infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS) have been used to confirm the chemically grafting reactions in every step. The conversion percent, grafting percent and grafting efficiency for VTMS-starch/p(MMA/BA/3FMA) latex indicate that the optimum conditions should be controlled at 75 °C for 1h as VTMS-starch/P(MMA/BA/3FMA) in 1/3 weight ratio. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis have revealed that the latexes exhibit the uniform spherical particles of 40-60 nm in a narrow size distribution. The latex films perform the obvious hydrophobic (107°) property, lower surface free energy (25-35 mN/m) and the higher thermostability (330-440 °C) than starch (51°, 51.32 mN/m, 100-330 °C). Dynamic thermomechanical analysis (DMA) shows that the latex film could gain considerable toughness and strength with an elongation at break of 39.45% and a tensile strength of 11.97 MPa. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Risk factors for and management of graft pancreatitis.

    Nadalin, Silvio; Girotti, Paolo; Königsrainer, Alfred

    2013-02-01

    Systematic and detailed analysis of risk factors, pathophysiology, clinical manifestation, diagnosis and management of graft pancreatitis in its different forms, that is acute and chronic graft pancreatitis (A-GP and C-GP), and A-GP being further distinguished into: physiological (P-AGP), early (E-AGP) and late AP (L-AGP). Graft pancreatitis is the second most-frequent complication following pancreas transplantation. P-AGP is an unavoidable entity related to ischemic reperfusion injury. It is usually clinically silent. It is a timely and prognostically self-limited process. E-AGP occurs within 3 months after pancreas transplantation (PTx) in 35% of cases and is associated with high rates of graft loss (78-91%). Clinical signs are pain, systemic inflammatory response (SIRS) and haematuria. Therapy can be medical, interventional and surgical. L-AGP occurs 3 months following PTx in 14-25% of cases and represents an uncommon cause of graft loss. Typical clinical signs are pain, abdominal tenderness and fever. Typical laboratory signs are hyperamylasaemia, hyperglycaemia and hypercreatininaemia. Therapy is usually conservative. C-GP is difficult to be distinguished from chronic rejection and is associated to graft loss in 4-10% of cases. Recurrent A-GPs and infections are the main risk factors. Specific symptoms are chronic abdominal malaise, constipation and recurrence of DM. Isolated hyperglycaemia is typical of C-GP. The therapy is usually conservative. This systematic analysis of different manifestations of graft pancreatitis provides the basis for a clinical approach to tackling this complex entity.

  2. New graft sizing rings for aortic valve reimplantation procedures.

    Jelenc, Matija; Jelenc, Blaž; Kneževic, Ivan; Klokocovnik, Tomislav

    2018-01-01

    The objective was to design sizing rings that would enable proper sizing of the graft in reimplantation procedures and to perform leaflet repair before graft implantation. The rings were designed in Autodesk Fusion 360 (San Rafael, CA, USA) and 3D printed using a commercial online 3D printing service. We designed incomplete rings with a low profile and complete rings with a high profile. The complete rings are best suited for reimplantation procedures, whereas low profile C rings are intended for isolated aortic valve repair, where the ascending aorta is not transected. The rings come in sizes corresponding to Vascutek Gelweave graft sizes (Vascutek Terumo, Renfrewshire, Scotland). The ring internal diameters are 5% larger than the designated ring sizes and account for the 5% stretch of the grafts when pressurized. Blades of the rings are placed at 20° intervals. The slits between the blades are designed in such a way that the commissural U-sutures, when put in place and under tension, will lock the ring in position. The rings were successfully used in 10 of our latest reimplantation procedures. After dissection of the aortic root, the commissures were suspended with U-stitches and then the ring was seated onto them. Complete leaflet repair with plication to achieve adequate effective height was then performed, followed by graft implantation. No additional leaflet repair was needed. The newly designed sizing rings enable proper sizing of the graft in reimplantation procedures and enable complete leaflet repair before graft implantation. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. Comparison of Alloderm and mucosal graft in mandibular vestibuloplasty

    Mahmoodhashemi H.

    2009-12-01

    Full Text Available "nBackground and Aim: The usage of free gingival grafts for vestibuloplasty is a routine procedure. The free gingival procedure requires harvesting the graft from a donor site which increases morbidity and the risk of surgical complications. In addition, adequate amount of donor tissue may not be available. Acceptable results of Alloderm application as a substitute for autogenous soft tissue grafts are: Not exposing the patient to an additional surgery, no donor site morbidity, unlimited availability, decreasing the bleeding during the surgery, decreasing the surgical complications, and better color match. The aim of this study was to evaluate the maintenance of the vestibular depth in vestibuloplasty with mucosal graft and Alloderm."nMaterials and Methods: Both methods of anterior mandibular vestibuloplasty by Clark, utilizing Alloderm and mucosal grafts, were employed in ten clinical cases. During the surgeries, half the prepared recipient sites received Alloderm, while the remaining half received autografts in a randomized fashion. Immediately, 1, 3, and 6 months postoperatively, the variables of graft rejection, depth of vestibule and the degree of relapse were evaluated. SPSS software was used for analysis of the data and the methods used for "statistical tests" were as follows: Friedman Method, Paired sample t-test, Smirnov-kolmogrove Method. (The statistical significance level was established at P-value<0.05."nResults: The mean difference of the relapse measurements in both methods throughout the survey did not have significant predictive value (P>0.05. Similar results were achieved for the mean difference of depth of the vestibule."nConclusion: In patients undergoing Vestibuloplasty, Alloderm could be material of choice to be utilized as autogenic soft tissue grafts in pre-prosthesis procedures.

  4. Radiation induced grafting of monomers onto natural rubber : processes and applications

    Sunny Sebastian, M.

    2001-01-01

    Full text: Certain inherent mechanical properties of natural rubber (NR) can be modified by grafting vinyl monomers onto the polymer backbone. This paper described the gamma radiation induced graft copolymerization of methyl methacrylate (MMA), styrene and acrylonitrile (AN) onto NR. The graft copolymers can be crosslinked by sulphur and organic accelerators. The crosslinked graft copolymers show improved modulus and hardness in their films compared to NR. However the tensile strength of the films is reduced by grafting. The methods for preparing the graft copolymers, their properties and applications are briefly described

  5. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    Docters, E. H.; Smolko, E. E.; Suarez, C. E.

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All this grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA).

  6. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    Docters, E.H.; Smolko, E.E.

    1990-01-01

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All these grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA). (author)

  7. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    Docters, E H; Smolko, E E [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Direccion de Radioisotopos y Radiaciones; Suarez, C E [Instituto Nacional de Tecnologia Agropecuaria, Castelar (Argentina)

    1990-01-01

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All these grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA). (author).

  8. Study of PVC membrane grafted by Acrylic Acid, Acrylonitrile and Acrylamide using preirradiation method

    Kattan, M.; Al-Kasseri, H.

    2015-03-01

    Grafting of acrylic acid, acrylamide and acrylonitrile onto poly vinyl chloride (PVC) films using gamma radiation has been carried out by both type direct and preirradiation methods. The effect of different parameter such as monomer concentration, inhibitor concentration, reaction temperature, reaction time and irradiation dose on the grafting yield were investigated. It was found that the grafting yield depends on these parameters. The grafting yield was strongly monomer dependent and grafting method: the highest was found for AAc by the preirradiation method. The samples were characterized by tensile strength measurement, swilling and ion uptake. The highest increase in swilling was observed on samples grafted with AAc by the preirradiation method.(author)

  9. Dependence of crystallinity degree with induced grafting by gamma radiation of N,N'-dimethyl acrylamide

    Queiroz, A.A.A.; Higa, O.Z.; Barrak, E.R.; Giolito, I.

    1991-01-01

    N,N' -dimethyl acrylamide (DMAA) graft copolymerization onto polyethylene films was carried out, using a organic solvent as a reaction medium and gamma rays from a 60 Co source for surface activation. Thermal analysis revealed the crystallinity and the grafting inversely proportional. The DSC curves fusion peaks decreased with grafting rate increase, the peak almost disappearing in the curve of PE 440% grafted. It was concluded that the graft occurs not only on the surface but also in the substrate bulk, being the PE absorption of DMAA an important factor for build up of grafted mass. (author)

  10. An unusual case of fistula formation and thrombosis between arteriovenous graft and a native vein

    Young Sub Kim

    2016-03-01

    Full Text Available Arteriovenous graft for hemodialysis vascular access is a widely used technique with many advantages. However, it has crucial complications with graft thrombosis and infection. We recently experienced an unusual case of arteriovenous graft complication involving graft thrombosis related to fistula formation between the graft and the natural vein with infection. We diagnosed this condition using Doppler ultrasound and computed tomography angiography. Successful surgical treatment including partial graft excision and creation of a secondary arteriovenous fistula using an inadvertently dilated cephalic vein was performed. The dialysis unit staff should keep this condition in mind and try to prevent this complication.

  11. Platlet Rich Plasma (PRP) Improves Fat Grafting Outcomes.

    Modarressi, Ali

    2013-01-01

    Autologous fat transfer offers many qualities of a ideal soft tissue filler. Main advantages of fat grafting ensue from the fact that the lipoaspirate tissue is an abundant source of regenerative pluripotential cells. However, the reported rates of fat cell survival vary greatly in the medical literature (10-90%). Different techniques of harvesting, processing, and reinjecting the fat cells are so claimed to be responsible for these differences, without any agreement concerning the best way to process. To address this important disadvantage, we propose the addition of autologous platelet rich plasma (PRP) which is known as a natural reservoir of growth factors stimulating tissue repair and regeneration. This approach is completely autologous and immediately employed without any type of preconditioning. Platelets rich plasma (PRP) preparation included bleeding of 8 ml of blood from patient's peripheral vein in Regen Lab© tubes containing sodium citrate anticoagulant. The whole blood was centrifugated at 1500 g during 3 min. As Regen-tubes contained a special gel separator, 99 % of red blood cells were discarded from the plasma at the bottom of the gel, and >90% of platelets were harvested in 4 ml of plasma on the top of the gel, called the platelet-rich plasma (PRP). The purified fat prepared by Coleman technique was mixed with different amount of PRP for in vitro, in vivo (mice) and clinical experiments: >50% of PRP for skin rejuvenation, superficial scars correction, infraorbital region, ..., and for 20% of PRP with 80% of purified fat for deep filler indication (nasolabial folds, lips, or soft tissue defect). In vitro studies demonstrated that PRP increased fat cells survival rate and stem cells differentiation. Animal models showed that fat graft survival rate was significantly increased by addition of PRP. Several clinical cases confirmed the improvement of wound healing and fat grafting survival in facial reconstruction and aesthetic cases by association of

  12. Genome-wide identification and comparative analysis of grafting-responsive mRNA in watermelon grafted onto bottle gourd and squash rootstocks by high-throughput sequencing.

    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.

  13. Decontamination of nuclear plant fluids with grafted celluloses

    Sandeaux, R.

    1991-01-01

    Ion exchange processes are specially well adapted techniques to solve some of nuclear plants problems, such as decontamination of the primary cooling circuit fluid and the cooling pool, because of the low concentration of the miscellaneous products to eliminate. Now the purification of these fluids is performed by using ion exchange resins. But recent researches show it is necessary to use more efficient techniques (1). The use of grafted celluloses should improve this process. The manufacturing of grafted celluloses was first performed with the collaboration of French Textile Institute and Morgane-Framatome (2). Cellulosic structure offers well known qualities for filtration: good micrometric retention, good mechanical behaviour, strong hydrophilic properties and high specific surface. Grafting was performed through a radiochemical process so as to bind polyelectrolytes on the backbone polymer. Compared to usual ion exchangers, these new materials offer different properties: - fast exchange kinetic - as uncrosslinked polymers, these grafted celluloses withstand better fouling with macroions or ionic complexes; - as they can be incinerated, radioactive wastes can be greatly reduced; - different commercial products of these grafted celluloses offer a wide range of possibilities for industrial uses [fr

  14. A Review on Grafting of Biofibers for Biocomposites

    Liqing Wei

    2016-04-01

    Full Text Available A recent increase in the use of biofibers as low-cost and renewable reinforcement for the polymer biocomposites has been seen globally. Biofibers are classified into: lignocellulosic fibers (i.e., cellulose, wood and natural fibers, nanocellulose (i.e., cellulose nanocrystals and cellulose nanofibrils, and bacterial cellulose, while polymer matrix materials can be petroleum based or bio-based. Green biocomposites can be produced using both biobased fibers and polymers. Incompatibility between the hydrophilic biofibers and hydrophobic polymer matrix can cause performance failure of resulting biocomposites. Diverse efforts have focused on the modification of biofibers in order to improve the performances of biocomposites. “Grafting” copolymerization strategy can render the advantages of biofiber and impart polymer properties onto it and the performance of biocomposites can be tuned through changing grafting parameters. This review presents a short overview of various “grafting” methods which can be directly or potentially employed to enhance the interaction between biofibers and a polymer matrix for biocomposites. Major grafting techniques, including ring opening polymerization, grafting via coupling agent and free radical induced grafting, have been discussed. Improved properties such as mechanical, thermal, and water resistance have provided grafted biocomposites with new opportunities for applications in specific industries.

  15. Removal of Industrial Pollutants From Wastewater's By Graft Copolymers

    Hegazy El-Sayed, A.; El-Nagar Abdel-Wahab, M.; Senna Magdy, M.; Zahran Abdel-Hamid, H.

    1999-01-01

    Graft copolymers that obtained by radiation grafting of acrylic acid and acrylamide onto LDPE film were converted to N-hydroxy ethyl amide and hydroxamic acid derivatives respectively. The possible application for the different prepared chemical derivatives of LDPE graft copolymers in metal adsorption from solutions containing a single cation or simulated medium active waste has been investigated. The results showed that the adsorption of Cu(II) metal by different chemical derivatives was greatly affected by different factors such as graft yield, ph value, concentration of metal in the feed solution, immersion time and treatment temperature. The affinity of N-hydroxy ethyl amide derivative toward the different metals was found to be in the order of; Cu(II) >Pd(II) > Cd(II)> Co(II). However, for hydroxamic acid derivative , the affinity order was: Cd(II) > Cu(II) > Co(II). The ESR and IR analysis revealed that the metal ions are chelated through the lone pair of electrons on the -OH and -NH- groups forming a ring structure. The measured metal ion uptake from simulated medium active waste mixture by N-hydroxy ethyl amide derivative was found to follow the following order: Fe> U> Ni> Zr> Zn> Cr. On the other hand, the measured metal uptake by hydroxamic acid derivative was found to follow: Fe>U> Zr> Ca. It is concluded that the prepared grafted copolymers are of interest for metal chelation and could be applied in the field of waste treatment

  16. Endovascular stent-graft management of thoracic aortic diseases

    Dake, Michael D.

    2001-01-01

    The traditional standard therapy for descending thoracic aortic aneurysm (TAA) is open operative repair with graft replacement of the diseased aortic segment. Despite important advances in surgical techniques, anesthetic management, and post-operative care over the last 30 years, the mortality and morbidity of surgery remains considerable, especially in patients at high risk for thoracotomy because of coexisting severe cardiopulmonary abnormalities or other medical diseases. The advent of endovascular stent-graft technology provides an alternative to open surgery for selected patients with TAA. The initial experience suggests that stent-graft therapy potentially may reduce the operative risk, hospital stay and procedural expenses of TAA repair. These potential benefits are especially attractive for patients at high risk for open TAA repair. Current results of endovascular TAA therapy document operative mortalities of between 0 and 4%, aneurysm thrombosis in 90 and 100% of cases, and paraplegia as a complication in 0 and 1.6% of patients. The early success of stent-graft repair of TAA has fostered the application of these devices for the management of a wide variety of thoracic aortic pathologies, including acute and chronic dissection, intramural hematoma, penetrating ulcer, traumatic injuries, and other diseases. The results of prospective controlled trials that compare the outcomes of stent-graft therapy with those of surgical treatment in patients with specific types of aortic disease are anxiously awaited before recommendations regarding the general use of these new devices can be made with confidence

  17. Study on superhydrophobic surfaces of octanol grafted electrospun silica nanofibers

    Meng, Long-Yue; Han, Shunyu; Jiang, Nanzhe; Meng, Wan

    2014-01-01

    In this work, superhydrophobic surfaces were successfully prepared by grafting of octanol on the surface of electrospun silica nanofibers (SNFs). The chemical compositions and microstructures of the prepared SNFs surfaces were investigated by using N 2 full isotherms, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The results indicate that the surface of SNFs changed from being superhydrophilic to superhydrophobic by octanol surface grafting. The contact angle of the octanol-grafted SNFs was close to 150.2° because their surface was modified by –(CH 2 ) 6 –CH 3 groups. The 3D network of SNFs networks and the low surface energy of the alkyl side chains played important roles in creating the superhydrophobic surface of the SNFs. - Highlights: • Superhydrophobic surface was prepared from electrospinning SNFs and by grafting octanol on their surface. • The surface of SNFs changed from superhydrophilic to superhydrophobic. • The CA of MSNFs became 150.2° because of interactions between grafted octyl groups

  18. Study on superhydrophobic surfaces of octanol grafted electrospun silica nanofibers

    Meng, Long-Yue [Key Laboratory of Natural Resources of Changbai Mountain and Functional Molecules, Yanbian University, Yanji 133002 (China); Department of Chemical Engineering, College of Engineering, Yanbian University, 977 Gongyuan Road, Yanji 133002 (China); Han, Shunyu; Jiang, Nanzhe [Department of Chemical Engineering, College of Engineering, Yanbian University, 977 Gongyuan Road, Yanji 133002 (China); Meng, Wan, E-mail: mengw@ybu.edu.cn [Department of Chemical Engineering, College of Engineering, Yanbian University, 977 Gongyuan Road, Yanji 133002 (China)

    2014-12-15

    In this work, superhydrophobic surfaces were successfully prepared by grafting of octanol on the surface of electrospun silica nanofibers (SNFs). The chemical compositions and microstructures of the prepared SNFs surfaces were investigated by using N{sub 2} full isotherms, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The results indicate that the surface of SNFs changed from being superhydrophilic to superhydrophobic by octanol surface grafting. The contact angle of the octanol-grafted SNFs was close to 150.2° because their surface was modified by –(CH{sub 2}){sub 6}–CH{sub 3} groups. The 3D network of SNFs networks and the low surface energy of the alkyl side chains played important roles in creating the superhydrophobic surface of the SNFs. - Highlights: • Superhydrophobic surface was prepared from electrospinning SNFs and by grafting octanol on their surface. • The surface of SNFs changed from superhydrophilic to superhydrophobic. • The CA of MSNFs became 150.2° because of interactions between grafted octyl groups.

  19. Obtaining of Grafted Planting Material at Some Romanian Tomatoes

    Madalina Doltu

    2016-11-01

    Full Text Available The tomatoes have highest share in Romanian crops from protected spaces (greenhouses, solariums. The grafting is an agronomical technique that induces or improves some qualities of the tomato cultivars (resistance to soil diseases and pests, resistance to abiotic factors, quantity and quality of fruit production. The research was aimed the establishing of the technological stages for producing of scion and rootstock seedlings from L. esculentum species, to obtain compatible phenotype when is grafted. The observations of this research were conducted on Department of Horticultural Cultures in Protected Spaces from Horting Institute Bucharest. The experience was carry out on a cultivar collection consisting from L. esculentum plants: scions (‘Siriana’–F1 hybrid and ‘Buzău 1600’– variety, creations from the germplasm bank of Research and Development Station for Vegetable Growing Buzău Romania (VDRS Buzău and rootstock (‘Groundforce’–F1 hybrid. The plant diameters were correlated for a grafting by the annexation method, cutting at 45 degrees. The grafting was performed successfully. The technological steps have achieved phenotypic compatibility of the symbiotes when was the grafting by annexation. The technology for producing of scion and rootstock seedlings at these Romanian tomatoes (‘Siriana’ and ‘Buzău’ 1600 was established for the crops in protected spaces in south area of Romania.

  20. Process for the graft polymerization of polyvinyl chloride. [electron beams

    Kageyama, E; Kusama, Y; Udagawa, A; Hashimoto, S

    1970-08-14

    The graft polymerization of acrylonitrile on polyvinyl chloride is effected by simultaneous irradiation with ionizing radiations in a reaction bath consisting of 30% acrylonitrile and 70% n-hexane. The acrylonitrile-hydrocarbon reaction bath increases the graft efficiency markedly when the content of acrylonitrile is 30%. In this case, the formation rate of acrylonitrile homopolymer decreases with a decrease in the content of acrylonitrile. The immersion time may be from a few minutes to a few hours, depending on the type, property and desired graft efficiency of the polyvinyl chloride resin. The polyvinyl chloride may be any available on the market. The acrylonitrile may contain a small quantity of copolymerizable monomer if it does not influence the thermal property of the polyvinyl chloride graft polymer. The ionizing radiations must have enough energy to form an ion pair by removing one electron from one atom of a gas. In examples, 10 g of polyvinyl chloride in powder form were immersed in 100 cc of a mixed solution consisting of 70% to 90% of n-hexane and 10% to 30% of acrylonitrile. The polyvinyl chloride in the solution was exposed to electron beams of 2 Mrad at a dose rate of 7.2 x 10/sup 7/ rad/hr. under a reduced pressure. The graft efficiency was 50% to 80% and the yield of acrylonitrile homopolymer was 0.42 g to 1.26 g.

  1. In vivo outcomes of tissue-engineered osteochondral grafts.

    Bal, B Sonny; Rahaman, Mohamed N; Jayabalan, Prakash; Kuroki, Keiichi; Cockrell, Mary K; Yao, Jian Q; Cook, James L

    2010-04-01

    Tissue-engineered osteochondral grafts have been synthesized from a variety of materials, with some success at repairing chondral defects in animal models. We hypothesized that in tissue-engineered osteochondral grafts synthesized by bonding mesenchymal stem cell-loaded hydrogels to a porous material, the choice of the porous scaffold would affect graft healing to host bone, and the quality of cell restoration at the hyaline cartilage surface. Bone marrow-derived allogeneic mesenchymal stem cells were suspended in hydrogels that were attached to cylinders of porous tantalum metal, allograft bone, or a bioactive glass. The tissue-engineered osteochondral grafts, thus created were implanted into experimental defects in rabbit knees. Subchondral bone restoration, defect fill, bone ingrowth-implant integration, and articular tissue quality were compared between the three subchondral materials at 6 and 12 weeks. Bioactive glass and porous tantalum were superior to bone allograft in integrating to adjacent host bone, regenerating hyaline-like tissue at the graft surface, and expressing type II collagen in the articular cartilage.

  2. Structure and transport properties of polymer grafted nanoparticles

    Goyal, Sushmit; Escobedo, Fernando A.

    2011-01-01

    We perform molecular dynamics simulations on a bead-spring model of pure polymer grafted nanoparticles (PGNs) and of a blend of PGNs with a polymer melt to investigate the correlation between PGN design parameters (such as particle core concentration, polymer grafting density, and polymer length) and properties, such as microstructure, particle mobility, and viscous response. Constant strain-rate simulations were carried out to calculate viscosities and a constant-stress ensemble was used to calculate yield stresses. The PGN systems are found to have less structural order, lower viscosity, and faster diffusivity with increasing length of the grafted chains for a given core concentration or grafting density. Decreasing grafting density causes depletion effects associated with the chains leading to close contacts between some particle cores. All systems were found to shear thin, with the pure PGN systems shear thinning more than the blend; also, the pure systems exhibited a clear yielding behavior that was absent in the blend. Regarding the mechanism of shear thinning at the high shear rates examined, it was found that the shear-induced decrease of Brownian stresses and increase in chain alignment, both correlate with the reduction of viscosity in the system with the latter being more dominant. A coupling between Brownian stresses and chain alignment was also observed wherein the non-equilibrium particle distribution itself promotes chain alignment in the direction of shear. © 2011 American Institute of Physics.

  3. High Rate Micromechanical Behavior of Grafted Polymer Nanoparticle Films

    Thomas, Edwin

    We report the ultra high strain rate behavior of films comprised of polymer grafted nanoparticles (NPs) and compare the results to homopolymer films. The films are formed by flow coating a suspension of polystyrene (PS) chains of 230 kg/mol grafted to 16nm diameter SiO2\\ at a graft density of 0.6 chains/nm2 resulting a film with 1 vol % SiO2. Films of 267 kg/mol PS were also flow coated and both films were impacted at velocities 350-700 ms-1 using 3.7 micron SiO2\\ projectiles to achieve increments in kinetic energy (KE) of 1:2:4. The KE of the projectiles before and after penetration was measured to determine the penetration energy. TEM and SEM suggest the projectile initially induces plastic flow due to the adiabatic temperature rise from impact. As the projectile deforms the film, the lower magnitude, biaxial stress state in the peripherial regions causes material microvoid formation and initiation of craze growth in the radial and tangential directions. The anchoring of the grafted polymer chains to the NPs increases the penetration energy relative to the pure homopolymer by 50% and the films capacity to delocalize the impact by 200%. These results suggest that highly grafted NP films may be useful in lightweight protection systems. In collaboration with Omri Fried, Olawale Lawal, Yang Jiao, Victor Hsaio, Thevamaran Ramathasan, Mujin Zhou, Richard Vaia.

  4. The study on grafting comonomer of n-butyl acrylate and styrene onto poly(ethylene terephthalate) film by gamma-ray induced graft copolymerization

    Ping Xiang; Wang Mozhen [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ge Xuewu, E-mail: xwge@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2010-09-15

    Poly(ethylene terephthalate) (PET) film was successfully grafted with n-butyl acrylate and styrene comonomer through gamma-ray induced graft copolymerization. The degree of grafting (DG) and the composition of grafted side chain were characterized by {sup 1}H NMR. It was found that St can inhibit the homopolymerization of BA effectively and increase the DG when the concentration of comonomer mixture is kept constant. The proportion of St to BA in grafted side chain has a positive dependence on the feed ratio of St, which ultimately approaches the feed ratio. The thermal properties of poly(ethylene terephthalate)-graft-poly(n-butyl acrylate-co-styrene) (PET-g-P(BA-co-St)) films were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The T{sub g} of PET decreases with the DG, indicating that the grafted P(BA-co-St) copolymer has good compatibility with PET backbone.

  5. Studies on the properties of poly (ethylene oxide) R-150 hydrogel films formed by irradiation graft

    Yang Zhanshan; Zhu Nankang; Yang Shuqin; Qiang Yizhong

    1999-01-01

    In order to improve the mechanical properties of poly (ethylene oxide) (PEO) hydrogel film was used as wound dressing. The chemical and physical properties of the PEO R-150 graft hydrogel film formed by blends of electron beam irradiated-PEO R-150 and poly(vinyl alcohol) (PVA) were studied. The experimental results showed that the crosslinking densities of the PEO R-150 graft hydrogel increased along with the increasing of the irradiation doses and decreased with the increasing of the blend concentrations. While the PVA graft proportions did not produce obvious effects on the crosslinking density of the graft hydrogel. The crosslinking density of the graft hydrogel were obviously lower than that of the pure PVA hydrogel. The equilibrium water content of the graft hydrogel decrease as the irradiation dose and the PVA graft proportion increased; but they increased as the blend concentration increased. The equilibrium water content of the graft hydrogel was obviously higher than those of the pure PVA hydrogel. The hardness of the PVA hydrogel film increased with the irradiation dose. The hardness of the graft hydrogel decreased with the blend concentration, whereas it increased with the PVA graft proportion. The results suggest the PVA produces a main effect on the crosslinking density of the graft hydrogel, the PEO R-150 produces a main effect on the equilibrium water content of the graft hydrogel, and the both polymers have double effects on the hardness of the graft hydrogel

  6. Radiation-induced grafting of sweet sorghum stalk for copper(II) removal from aqueous solution

    Dong, Jing; Hu, Jun; Wang, Jianlong

    2013-01-01

    Highlights: • Radiation-induced grafting was used to modify the stalk. • Cellulose, hemicellulose and lignin participated in grafting reaction. • Both the structure and composition of stalk had influence on grafting. • The sorption capacity of the grafted stalk increased about five times. -- Abstract: The influence of main components (cellulose, hemicellulose and lignin) of the sweet sorghum stalk on radiation-induced grafting reaction and adsorption of copper from aqueous solution was investigated. Sweet sorghum stalk was grafted with acrylic acid induced by γ-irradiation. The results showed that the grafted stalk contained 1.6 mmol/g carboxyl groups, and its maximal adsorption capacity was 13.32 mg/g. The cellulose, hemicellulose and lignin of the raw materials were confirmed to involve in grafting reaction through comparing the grafting yield and the structure of the grafted materials. Both the structure and the composition of the sweet sorghum stalk had influence on the grafting reaction and adsorption capacity. The adsorption capacity of the grafted sweet sorghum stalk increased about five times, and the adsorption isotherm of the grafted materials conformed to the Langmuir model. The main mechanism for copper adsorption involved in ion exchange

  7. Graft copolymerization of glycidyl methacrylate onto delignified kenaf fibers through pre-irradiation technique

    Sharif, Jamaliah; Mohamad, Siti Fatahiyah; Fatimah Othman, Nor Azilah; Bakaruddin, Nurul Azra; Osman, Hasnul Nizam; Güven, Olgun

    2013-01-01

    Glycidyl methacrylate grafted kenaf (GMA-g-Kenaf) was prepared by pre-irradiation grafting technique. Kenaf fibers were treated with different concentration of sodium chlorite solution before used as trunk polymer. Treated kenaf fibers were irradiated by electron beam followed by grafting reaction in GMA/water emulsion system. The degree of grafting was determined as a function of absorbed dose, reaction time, reaction temperature and concentration of monomer. The results showed that the lignin content was decreased from 14.3% to as low as 3.3% with the increased of sodium chlorite concentration. This was evidenced by SEM pictures which show the surface of treated kenaf fibers was cleaner and smoother compared to that of untreated one. The degree of grafting increased with the increase of absorbed dose, reaction temperature, reaction time and monomer concentration as well as with decreasing lignin content. Formation of graft copolymer was confirmed with SEM, FTIR analysis. The structural investigation by XRD showed that degree of crystallinity of graft copolymers decreased with the increase in degree of grafting. - Highlights: • We used kenaf fibers for radiation induce graft copolymerization with GMA. • Kenaf fibers was treated to remove lignin in order to increase grafting yield. • Treated kenaf fibers were graft copolymerize through preirradiation technique. • Optimum conditions for graft copolymerization of kenaf fibers were established. • Formation of graft copolymer is also confirmed with SEM, FTIR and XRD

  8. Interaction of blood with radiation-grafted materials

    Ikada, Y.; Suzuki, M.; Taniguchi, M.; Iwata, H.; Taki, W.; Miyake, H.; Yonekawa, Y.; Handa, H.

    1981-01-01

    Extensive works on blood compatibility of polymeric materials have revealed that it is strongly governed by their surface structure and properties. Among them are roughness, hydrophobic-hydrophilic balance, ionic species, and water content in the surface layer. In the present work, low and high density polyethylenes as well as heat-treated poly(vinyl) alcohol are grafted with acrylamide (and acrylic acid for comparison) by a pre-irradiation technique to convert the rigid hydrophobic surface into a soft hydrogel with high water contents. The surface modification of materials with grafted polyacrylamide chains will be confirmed from the contact angle measurement which is one of the best methods for assessing the hydrophilicity of surfaces. Blood compatibility of the resulting surfaces will be evaluated from in vivo experiments by anastomosing the surface-grafted tubes of small diameter with the carotid artery of rat. (author)

  9. Polyaniline-grafted reduced graphene oxide for efficient electrochemical supercapacitors.

    Kumar, Nanjundan Ashok; Choi, Hyun-Jung; Shin, Yeon Ran; Chang, Dong Wook; Dai, Liming; Baek, Jong-Beom

    2012-02-28

    An alternative and effective route to prepare conducting polyaniline-grafted reduced graphene oxide (PANi-g-rGO) composite with highly enhanced properties is reported. In order to prepare PANi-g-rGO, amine-protected 4-aminophenol was initially grafted to graphite oxide (GO) via acyl chemistry where a concomitant partial reduction of GO occurred due to the refluxing and exposure of GO to thionyl chloride vapors and heating. Following the deprotection of amine groups, an in situ chemical oxidative grafting of aniline in the presence of an oxidizing agent was carried out to yield highly conducting PANi-g-rGO. Electron microscopic studies demonstrated that the resultant composite has fibrillar morphology with a room-temperature electrical conductivity as high as 8.66 S/cm and capacitance of 250 F/g with good cycling stability.

  10. Aspirin decreases platelet uptake on Dacron vascular grafts in baboons

    Mackey, W.C.; Connolly, R.J.; Callow, A.D.

    1984-01-01

    The influence of a single dose of aspirin (5.4-7.4 mg/kg) on platelet uptake on 4-mm Dacron interposition grafts was studied in a baboon model using gamma camera scanning for 111-Indium labeled platelets. In vitro assessment of platelet function after aspirin administration revealed that in the baboon, as in the human, aspirin abolished arachidonic acid-induced platelet aggregation, prolonged the lag time between exposure to collagen and aggregation, and decreased plasma thromboxane B2 levels. Aspirin also prolonged the template bleeding time. Scans for 111-Indium labeled platelets revealed that pretreatment with a single dose of aspirin decreased platelet uptake on 4-mm Dacron carotid interposition grafts. This decrease in platelet uptake was associated with a significant improvement in 2-hour graft patency and with a trend toward improved 2-week patency

  11. Dressing for alveolopalatal wounds after alveolar bone grafting.

    Kondoh, Shoji; Matsuo, Kiyoshi; Yuzuriha, Shunsuke; Kikuchi, Nirou; Ban, Ryokuya

    2003-09-01

    Cotton gauze with alpha cyanoacrylate was used for alveolopalatal wound dressing after alveolar bone grafting to treat 93 alveolar clefts in 74 cleft patients to reduce mechanical injuries, tension for wound dehiscence, and adhesion of food remnants. T-shaped cotton gauze was put on the gingivoperiosteal flaps and was impregnated with cyanoacrylate. The procedure required no preoperative preparation and its intraoperative execution took less than 5 minutes. The gauze with cyanoacrylate was removed approximately 1 week after surgery. No infection was observed at any of the operational sites, but tiny fistulas developed at four of them. The mean bone graft score was 1.4 point. No complications such as thermal injury resulted from the use of cyanoacrylate. Gauze impregnated with cyanoacrylate proved to be a convenient and dependable dressing for alveolopalatal wounds resulting from gingivoperiosteoplasty for alveolar bone grafting.

  12. [Kidney graft loss as a result of coagulation disorders].

    Kulik, Agnieszka

    2012-04-01

    Renal transplantation is a method of choice in the treatment of endstage kidney insufficiency resulting in improved survival and better quality of life. Advances in immunosuppresive therapy, diagnosis and treatment of infective complications, studies on ischemic injury of transplanted organ and preservation show constant improvement in terms of short and long-term results. Early kidney graft loss resulting from thrombotic complications is rare and still challenging for transplantologists. Renal vein thrombosis is responsible for 2-7% cases of early graft loss. Selecting a subset of patients threatened with thromboembolic complications will allow for starting adequate prophylaxis, or early treatment preventing from complications including graft loss. In this paper we tried to summarize the current state of knowledge regarding venous and arterial thrombosis after renal transplantation.

  13. Ion exchange fiber prepared by radiation grafting, (2)

    Sekiguchi, Hideaki; Fujiwara, Kunio; Fujii, Toshiaki; Takai, Takeshi; Kobayashi, Atsushi

    1991-01-01

    Ion exchange fiber prepared by radiation grafting has the capabilities for wide application as high performance materials. Extensive studies were made to evaluate the ion exchange fiber prepared by radiation grafting for removing some toxic or malodorous gases, continuing from the previous work (presented in Ebara Engng. Review, No. 146), in which the ability of removing ammonia with cation exchange fiber was investigated. The results of this study can be summarized by the following conclusions: (1) Methods of evaluating the ability of removing ammonia, acetaldehyde, and some lower fatty acids in low concentration were established, (2) Besides being effective for the removal of acidic or basic gases, neutral gas such as acetaldehyde can also be removed by adding some functional compounds to the ion exchange fiber, and (3) Ion exchange fiber prepared by radiation grafting is effective as a deodorizing filter. (author)

  14. Robot-Assisted Antegrade In-Situ Fenestrated Stent Grafting

    Riga, Celia V.; Bicknell, Colin D.; Wallace, Daniel; Hamady, Mohamad; Cheshire, Nicholas

    2009-01-01

    To determine the technical feasibility of a novel approach of in-situ fenestration of aortic stent grafts by using a remotely controlled robotic steerable catheter system in the porcine model. A 65-kg pig underwent robot-assisted bilateral antegrade in-situ renal fenestration of an abdominal aortic stent graft with subsequent successful deployment of a bare metal stent into the right renal artery. A 16-mm iliac extension covered stent served as the porcine aortic endograft. Under fluoroscopic guidance, the graft was punctured with a 20-G customized diathermy needle that was introduced and kept in place by the robotic arm. The needle was exchanged for a 4 x 20 mm cutting balloon before successful deployment of the renal stent. Robot-assisted antegrade in-situ fenestration is technically feasible in a large mammalian model. The robotic system enables precise manipulation, stable positioning, and minimum instrumentation of the aorta and its branches while minimizing radiation exposure.

  15. Free epidural fat-grafting after lumbar laminectomy using MRI

    Ohtsubo, Yoshimasa; Fujita, Masaaki; Motokawa, Satoru; Nakamura, Satoshi; Narabayashi, Yoko

    1994-01-01

    Free epidural fat-grafting was performed to prevent adhesion between scar tissue of the epidural space and dura and nerve root after lumbar laminectomy. The results were evaluated using MRI. Fifteen cases were operated upon with an average follow-up period of 7.5 months. MRI was recorded and the findings were classified into four types as follow: I, equally high signal case; II, slight fibrosis case; III, severe fibrosis case; IV, high signal disappeared case. The results showed 3 cases of type I, 7 cases of type II, 3 cases of type III, and 2 cases of type IV. According to MRI findings, free epidural fat is supposed to be still viable and alive, although slightly fibroses but the dural side remains a high signal area. Free epidural fat-grafting was useful for preventing adhesion around the epidural space. There was high relationship to age and sex with regard to viability of the free fat graft. (author)

  16. Sorption behaviour of polystyrene grafted sago starch in various solvents

    Janarthanan, P.; Yunus, W.M.Z.W.; Ahmed, M.B.; Rahman, M.Z.; Haron, M.J.; Silong, S.

    2001-01-01

    This paper describes swelling properties of polystyrene grafted sago starch in dimethyl sulfoxide (DMSO); chloroform (CHCl/sub 3/), water, acetone carbon tetrachloride (CCl/sub 4/) cyclohexanone and toluene. The copolymer for this study was prepared by grafting styrene onto sago starch using ceric ammonium nitrate as a redox initiator. Solvent uptake of the copolymer with respect to time was obtained by soaking the samples in chosen solvents for various time intervals at 25+-1 degree centigrade. The results obtained from swelling of polystyrene grafted sago starch in polar and non polar solvents showed that the percentage of swelling at equilibrium and the swelling rate coefficient decreased in the following order: DMSO > water > acetone cyclohexanone approx. CHCl/sub 3/ > toluene approx. CCl/sub 4/. Dimethyl sulfoxide showed the highest percentage of swelling at equilibrium that is 765%. Diffusions of the solvents onto the polymers were found to be of a Fickian only for DMSO. (author)

  17. Au-nanoparticles grafted on plasma treated PE

    Svorcik, V.; Chaloupka, A.; Rezanka, P.; Slepicka, P.; Kolska, Z.; Kasalkova, N.; Hubacek, T.; Siegel, J.

    2010-01-01

    Polyethylene (PE) surface was treated with Ar plasma. Activated surface was grafted from methanol solution of 1,2-ethanedithiol. Then the sample was immersed into freshly prepared colloid solution of Au-nanoparticles. Finally Au layer was sputtered on the samples. Properties of the modified PE were studied using various methods: AFM, EPR, RBS and nanoindentation. It was shown that the plasma treatment results in degradation of polymer chain (AFM) and creation of free radicals by EPR. After grafting with dithiol, the concentration of free radicals declines. The presence of Au and S in the surface layer after the coating with Au-nanoparticles was proved by RBS. Plasma treatment changes PE surface morphology and increases surface roughness, too. Another significant change in surface morphology and roughness was observed after deposition of Au-nanoparticles. Nanoindentation measurements show that the grafting with Au-nanoparticles increases adhesion of subsequently sputtered Au layer.

  18. Immobilized enzymes in blood plasma exchangers via radiation grafting

    Gombotz, Wayne; Hoffman, Allan; Schmer, Gottfried; Uenoyama, Satoshi

    The enzyme asparaginase was immobilized onto a porous hollow polypropylene (PP) fiber blood plasma exchange device for the treatment of acute lymphocytic leukemia. The devices were first radiation grafted with polymethacrylic acid (poly(MAAc)). This introduces carboxyl groups onto the surface of the fibers. Several variables were studied in the grafting reaction including the effects of solvent type and monomer concentration. The carboxyl groups were activated with N-hydroxy succinimide (NHS) using carbodiimide chemistry. Asparaginase was then covalently immobilized on the activated surfaces. Quantitative relationships were found relating the percent graft to the amount of immobilized enzyme which was active. The enzyme reactor was tested both in vitro and in vivo using a sheep as an animal model.

  19. [Surface grafting modification and stabilization of Kevlar fiber].

    Zheng, Yu-ying; Fu, Ming-lian; Wang, Can-yao; Wang, Liang-en

    2005-11-01

    Chemical disposal was used to bring the activity group onto the surface of Kevlar fiber for the purpose of surface grafting modification. The interfacial constitution of the grafting of toluene-2,4-diisocyanate (TDI) onto Kevlar fiber was determined by Fourier transform infrared spectroscopy. In the mean time, hexyl-lactam stabilization and poly-glycol (400, PEG) stabilization on the grafted product were also studied. The effects of different nTDI:nPEG ratios on the production's interfacial constitution was analysed. It is concluded that the stabilization took place on the surface. The intensity of the bands relented at about 3300 cm(-1) and was reinforced at about 1700-1720 cm(-1) when the ratio of nTDI:nPEG = 1:3, but when the ratio is 1:1 and 1:2, the bands at about 3 300 and 1700-1720 cm(-1) are almost the same.

  20. Dermofat graft in deep nasolabial fold and facial rhytidectomy.

    Hwang, Kun; Han, Jin Yi; Kim, Dae Joong

    2003-01-01

    Fat and dermis or the combined tissues are used commonly in augmentation of the nasolabial fold. Guyuron obtained the dermofat graft from either the suprapubic or the groin region. The thickness of the preauricular skin was measured in seven Korean cadavers, five male and two female. We used the dermofat graft out of the preauricular skin remnant after facial rhytidectomy to augment the deep nasolabial fold in a patient. The average thickness of the epidermis was 56 +/- 12 microm, the dermis was 1820 +/- 265 microm thick, and the subcutaneous tissue was 4783 +/- 137 microm. More dense connective tissues, such as SMAS, are seen in the preauricular skin. The dermofat graft was easily obtained and prepared from the leftover preauricular skin after dissection of the lax skin in face lifting. This technique could be employed effectively and successfully to alleviate a deep nasolabial fold and concomitant facial rhytidectomy in an Asian with a thick preauricular skin.

  1. Prostanoids modulate inflammation and alloimmune responses during graft rejection

    P.N. Rocha

    2005-12-01

    Full Text Available Acute rejection of a transplanted organ is characterized by intense inflammation within the graft. Yet, for many years transplant researchers have overlooked the role of classic mediators of inflammation such as prostaglandins and thromboxane (prostanoids in alloimmune responses. It has been demonstrated that local production of prostanoids within the allograft is increased during an episode of acute rejection and that these molecules are able to interfere with graft function by modulating vascular tone, capillary permeability, and platelet aggregation. Experimental data also suggest that prostanoids may participate in alloimmune responses by directly modulating T lymphocyte and antigen-presenting cell function. In the present paper, we provide a brief overview of the alloimmune response, of prostanoid biology, and discuss the available evidence for the role of prostaglandin E2 and thromboxane A2 in graft rejection.

  2. Surface grafted polymer brushes: potential applications in dengue biosensors

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco, E-mail: ozahiga@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de, E-mail: alencar@unifei.edu.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Instituto de Fisica e Quimica

    2013-07-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar{sup +} ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  3. Surface grafted polymer brushes: potential applications in dengue biosensors

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco; Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de

    2013-01-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar + ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

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

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

    2003-01-01

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

  5. Spontaneous grafting of diazonium salts: chemical mechanism on metallic surfaces.

    Mesnage, Alice; Lefèvre, Xavier; Jégou, Pascale; Deniau, Guy; Palacin, Serge

    2012-08-14

    The spontaneous reaction of diazonium salts on various substrates has been widely employed since it consists of a simple immersion of the substrate in the diazonium salt solution. As electrochemical processes involving the same diazonium salts, the spontaneous grafting is assumed to give covalently poly(phenylene)-like bonded films. Resistance to solvents and to ultrasonication is commonly accepted as indirect proof of the existence of a covalent bond. However, the most relevant attempts to demonstrate a metal-C interface bond have been obtained by an XPS investigation of spontaneously grafted films on copper. Similarly, our experiments give evidence of such a bond in spontaneously grafted films on nickel substrates in acetonitrile. In the case of gold substrates, the formation of a spontaneous film was unexpected but reported in the literature in parallel to our observations. Even if no interfacial bond was observed, formation of the films was explained by grafting of aryl cations or radicals on the surface arising from dediazoniation, the film growing later by azo coupling, radical addition, or cationic addition on the grafted phenyl layer. Nevertheless, none of these mechanisms fits our experimental results showing the presence of an Au-N bond. In this work, we present a fine spectroscopic analysis of the coatings obtained on gold and nickel substrates that allow us to propose a chemical structure of such films, in particular, their interface with the substrates. After testing the most probable mechanisms, we have concluded in favor of the involvement of two complementary mechanisms which are the direct reaction of diazonium salts with the gold surface that accounts for the observed Au-N interfacial bonds as well as the formation of aryl cations able to graft on the substrate through Au-C linkages.

  6. Sarpogrelate hydrochloride reduced intimal hyperplasia in experimental rabbit vein graft.

    Kodama, Akio; Komori, Kimihiro; Hattori, Keisuke; Yamanouchi, Dai; Kajikuri, Junko; Itoh, Takeo

    2009-05-01

    The selective 5-HT(2A) receptor antagonist sarpogrelate has been clinically used for treatment in atherosclerotic diseases. However, it remains unknown whether administration of sarpogrelate inhibits intimal hyperplasia seen in autologous vein grafts. Therefore, we sought to clarify this question using an experimental rabbit vein graft model. Male rabbits were divided into two groups: a control group and a sarpogrelate-treated group. The jugular vein was interposed in the carotid artery in reversed fashion for 4 weeks and intimal hyperplasia of the grafted vein was measured (n = 8, in each group). Acetylcholine (ACh)-induced endothelium-dependent relaxation was tested by precontraction with prostaglandin F(2alpha) (PGF(2alpha), 5 muM) (n = 5, in each). endothelial nitric oxide synthase (eNOS) protein expression and superoxide production of these veins were also assessed. The suppression of intimal hyperplasia was significantly greater in the sarpogrelate-treated group than in the control group. ACh induced an endothelium-dependent relaxation in the sarpogrelate-treated group (but not in the control group). In endothelium-intact strips from the sarpogrelate-treated group, the nitric oxide (NO) synthase inhibitor nitroarginine enhanced the PGF(2alpha)-induced contraction and blocked the ACh-induced relaxation. Immunoreactive eNOS protein expression was similar between the two groups but superoxide production (estimated from ethidium fluorescence) in endothelial cells was significantly smaller in the sarpogrelate-treated group. The present results indicate that in vivo blockade of 5-HT(2A) receptors leads to an inhibition of intimal hyperplasia in rabbit vein graft. It is suggested that an increased function of endothelium-derived NO through a reduction in endothelial superoxide production may be a possible underlying mechanism for this. These novel findings support the clinical usefulness of sarpogrelate for preventing intimal hyperplasia in vein graft after bypass

  7. The Use of Grafting to Study Systemic Signaling in Plants.

    Tsutsui, Hiroki; Notaguchi, Michitaka

    2017-08-01

    Grafting has long been an important technique in agriculture. Nowadays, grafting is a widely used technique also to study systemic long-distance signaling in plants. Plants respond to their surrounding environment, and at that time many aspects of their physiology are regulated systemically; these start from local input signals and are followed by the transmission of information to the rest of the plant. For example, soil nutrient conditions, light/photoperiod, and biotic and abiotic stresses affect plants heterogeneously, and plants perceive such information in specific plant tissues or organs. Such environmental cues are crucial determinants of plant growth and development, and plants drastically change their morphology and physiology to adapt to various events in their life. Hitherto, intensive studies have been conducted to understand systemic signaling in plants, and grafting techniques have permitted advances in this field. The breakthrough technique of micrografting in Arabidopsis thaliana was established in 2002 and led to the development of molecular genetic tools in this field. Thereafter, various phenomena of systemic signaling have been identified at the molecular level, including nutrient fixation, flowering, circadian clock and defense against pathogens. The significance of grafting is that it can clarify the transmission of the stimulus and molecules. At present, many micro- and macromolecules have been identified as mobile signals, which are transported through plant vascular tissues to co-ordinate their physiology and development. In this review, we introduce the various grafting techniques that have been developed, we report on the recent advances in the field of plant systemic signaling where grafting techniques have been applied and provide insights for the future. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Hollow fiber membrane lumen modified by polyzwitterionic grafting

    Le, Ngoc Lieu

    2016-08-24

    In this study, we demonstrate an effective way to modify the lumen of polyetherimide hollow fibers by grafting zwitterionic poly(sulfobetaine) to increase the membrane resistance to fouling. Surface-selective grafting of the protective hydrogel layers has been achieved in a facile two-step process. The first step is the adsorption of a macromolecular redox co-initiator on the lumen-side surface of the membrane, which in the second step, after flushing the lumen of the membrane with a solution comprising monomers and a complementary redox initiator, triggers the in situ cross-linking copolymerization at room temperature. The success of grafting reaction has been verified by the surface elemental analyses using X-ray photoelectron spectroscopy (XPS) and the surface charge evaluation using zeta potential measurements. The hydrophilicity of the grafted porous substrate is improved as indicated by the change of contact angle value from 44° to 30°, due to the hydration layer on the surface produced by the zwitterionic poly(sulfobetaine). Compared to the pristine polyetherimide (PEI) substrate, the poly(sulfobetaine) grafted substrates exhibit high fouling resistance against bovine serum albumin (BSA) adsorption, E. coli attachment and cell growth on the surface. Fouling minimization in the lumen is important for the use of hollow fibers in different processes. For instance, it is needed to preserve power density of pressure-retarded osmosis (PRO). In high-pressure PRO tests, a control membrane based on PEI with an external polyamide selective layer was seriously fouled by BSA, leading to a high water flux drop of 37%. In comparison, the analogous membrane, whose lumen was modified with poly(sulfobetaine), not only had a less water flux decline but also had better flux recovery, up to 87% after cleaning and hydraulic pressure impulsion. Clearly, grafting PRO hollow fiber membranes with zwitterionic polymeric hydrogels as a protective layer potentially sustains PRO

  9. Paediatric fingertip composite grafts: Do they all go black?

    Murphy, Adrian D; Keating, Cameron P; Penington, Anthony; McCombe, David; Coombs, Chris J

    2017-02-01

    Fingertip injuries are amongst the most frequently seen hand injuries in the paediatric population. The present study evaluated the composite graft survival rate in distal digital amputations with respect to injury type, amputation level and time to surgery. We performed a retrospective review of patients who underwent composite grafting of fingertip injuries over an 11-year period at a paediatric hospital. All children who underwent non-vascularized replantation of amputated fingertips were included. Patients were excluded if they failed to attend at least one follow-up appointment. Demographic information was recorded. The nature and level of injury and time to surgery was also recorded. Graft viability was characterized as no take, partial take, or complete take. The number of secondary procedures and number and duration of follow-up appointments were recorded. A total of 105 patients underwent fingertip composite grafting, of whom 96 were suitable for inclusion in this study. The median age was 2.4 years (0-16 years); there were 48 boys (46%) and 57 girls (54%). Thirty-one patients had no graft take (32%), 50 patients had partial take (52%) and 15 patients had complete take (16%). Only two patients underwent secondary revision (2%). The median number of follow-up appointments was 4, and the mean follow-up time was 68 days. Time to surgery or level of amputation did not have a statistically significant influence on outcome. Over two-thirds of composite grafts in children showed some degree of take, albeit partially in the majority. Morbidity was low, and most children did not require further surgery. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. Tear trough – Anatomy and treatment by autologous fat grafting

    Chang Yung Chia

    2016-07-01

    Full Text Available Tear trough is the main irregularity at midface, of which treatment is difficult. There is no agreement in literature about its anatomy and best treatment. The author presented an anatomical study and personal autologous fat grafting technique for tear trough treatment. Anatomical dissections were done on two fresh cadavers to examine the skin, subcutaneous, muscle and bone layers, spaces, and attachments. Safety and efficacy were evaluated via retrospective analysis of the last 200 consecutive procedures performed by the author. Tear trough is caused by the abrupt transition of the palpebral orbicular oculi muscle (OOM (i.e., thin skin without subcutaneous fat compartment to the orbital OOM (i.e., thicker skin with malar fat compartment. The tear trough region is located at the OOM bony origin at the medial canthus where no specific ligament was found. The grafted fat volume stabilized at two or three months after the procedure, instead of six months as stated in literature, with excellent results and no severe complications. Tear trough is a personal characteristic, a natural anatomical depression caused by subcutaneous irregularity and can worsen with age. The lack of volume is not effectively corrected by surgeries and thus it must be filled. Fat grafting has several advantages over alloplastic fillers, although it may be more difficult. Fat graft is autologous and abundant, and tissue transplantation could enhance skin quality. Fat grafting is a simple, safe, and effective solution for adding extra volume to correct the deflation phenomenon of the midface aging process. There is no specific anatomical plane for volume injection; the fat graft must be evenly distributed in the deep and superficial plane for uniformity.

  11. Magnetizable stent-grafts enable endothelial cell capture

    Tefft, Brandon J.; Uthamaraj, Susheil; Harburn, J. Jonathan; Hlinomaz, Ota; Lerman, Amir; Dragomir-Daescu, Dan; Sandhu, Gurpreet S.

    2017-04-01

    Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance.

  12. Capturing of staphylococcus aureus onto an interface containing graft chains

    Lee, W.; Furusaki, Shintaro; Saito, Kyoichi; Sugo, Takanobu; Makuuchi, Keizo.

    1995-01-01

    A microbial-cell-capturing material was prepared by radiation-induced grafting of glycidyl methacrylate onto a polyethylene-based fiber before the introduction of diethylamine. The prepared fiber was tested against a Staphylococcus aureus and Escherichia coli solution. The results showed that the grafted-type fiber had a capturing rate constant 1000-fold higher than the commercial crosslinked-type bead for S. aureus and that an activation energy of 39 kJ/mol was obtained for the microbial-cell-capturing action. (author)

  13. Radiation induced ionic polymerisation and grafting of vinyl monomers

    Stannett, V.T.

    1981-01-01

    Some special aspects of the radiation induced ionic polymerisation and grafting of vinyl monomers will be described. In particular the effects of solvents on the cationic polymerisation of the vinyl ethers will be discussed in detail. The unequivocal free ion nature of the polymerisation makes such information of considerable general interest. Estimates of the propagation rate constants with free cation polymerisation in solvents of different dielectric constants and solvation powers will be presented. Finally, some observations on the radiation induced graft polymerisation of ethyl vinyl ether to poly(vinyl chloride) and to polypropylene will be presented. (author)

  14. Structural Transitions of Solvent-Free Oligomer-Grafted Nanoparticles

    Chremos, Alexandros

    2011-09-01

    Novel structural transitions of solvent-free oligomer-grafted nanoparticles are investigated by using molecular dynamics simulations of a coarse-grained bead-spring model. Variations in core size and grafting density lead to self-assembly of the nanoparticles into a variety of distinct structures. At the boundaries between different structures, the nanoparticle systems undergo thermoreversible transitions. This structural behavior, which has not been previously reported, deviates significantly from that of simple liquids. The reversible nature of these transitions in solvent-free conditions offers new ways to control self-assembly of nanoparticles at experimentally accessible conditions. © 2011 American Physical Society.

  15. Considerations in setting up and planning a graft processing facility.

    Koh, Mickey B C

    2017-12-01

    The graft processing facility forms one of the core components of a clinical haematopoietic stem cell transplant program. The quality of a graft is instrumental in leading to consistent and reproducible outcomes of engraftment and other parameters. As such, meticulous planning and consideration is required and will include core elements including physical design and clinical correlates. The successful running of such a facility depends on an overarching quality program and adherence to local and international regulatory guidelines. Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

  16. Grafting, pruning, and the antipodal map on measured laminations

    Dumas, David

    2006-01-01

    Grafting a measured lamination on a hyperbolic surface defines a self-map of Teichmuller space, which is a homeomorphism by a result of Scannell and Wolf. In this paper we study the large-scale behavior of pruning, which is the inverse of grafting. Specifically, for each conformal structure $X \\in \\T(S)$, pruning $X$ gives a map $\\ML(S) \\to \\T(S)$. We show that this map extends to the Thurston compactification of $\\T(S)$, and that its boundary values are the natural antipodal involution relat...

  17. Iatrogenic giant cell tumor at bone graft harvesting site

    Zile S Kundu

    2013-01-01

    Full Text Available 30 year old female patient with giant cell tumor of the distal tibia initially treated at a peripheral nononcological center by curettage and autologous bone grafting from the ipsilateral iliac crest reported to us with local recurrence and an implantation giant cell tumor at the graft harvesting site which required extensive surgeries at both sites. The risk of iatrogenic direct implantation of tumor, often attributable to inadequate surgical planning or poor surgical techniques, and the steps to prevent such complication is reported here.

  18. Brushes and soap : grafted polymers and their interactions with nanocolloids

    Currie, E.P.K.

    2000-01-01

    Layers of polymer chains end-attached to a grafting plane at high densities, so-called brushes, are a curious state of matter. The (average) monomer density within the brush is as high as in a semi-dilute polymer solution, resulting in a high osmotic pressure in the brush. Due to the grafting, however, this isotropic osmotic pressure results in an anisotropic stretching of the chains normal to the surface. This degree of stretching can be quite extensive; in this thesis PEO-chains of...

  19. Revascularization of autogenous skin grafts placed on irradiated tissue

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

    1982-01-01

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

  20. Use of Preputial Skin as Cutaneous Graft after Nevus Excision

    A. D'Alessio

    2010-01-01

    Full Text Available We report a four-year-old boy with a nevus covering all the plantar side of his second finger on the left foot. He was also affected by congenital phimosis. Surgical excision of the nevus was indicated, but the skin defect would have been too large to be directly closed. The foreskin was taken as a full-thickness skin graft to cover the cutaneous defect of the finger. The graft intake was favourable and provided a functional repair with good aesthetic characteristic.