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Sample records for artificial nerve grafts

  1. Biocompatibility studies of silk fibroin-based artificial nerve grafts in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Silk fibroin (SF) has been used extensively in the biomedical field including tissue engineering for the generation of artificial bones, skins or ligaments. We have previously reported on good in vitro biocompatibility of SF fibers with peripheral nerve tissues and cells. In the present study, we developed a novel design of the SF-based artificial nerve graft (SF graft) which was composed of a SF-nerve guidance conduit (NGC) inserted with SF fibers. MTT assay was performed to determine the cytotoxicity of the SF-NGC extract fluid on the cultured L929 cells derived from an immortalized mouse fibroblast cell line. In addition, this SF graft was implanted into adult rats for bridging a 10-mm long sciatic nerve defect. The following-up experiments at initial stage (1-4 week) of nerve regeneration including routine blood tests and histochemical investigation were conducted to evaluate the in vivo biocompatibility of the SF graft with peripheral nerves. The results demonstrated that the SF-NGC graft was biocompatible with the surrounding tissues and cells due to its low inflammatory potential with a grade O under the U. S. Pharmacopeia guidelines and it was generally suitable to a certain degree for bridging peripheral nerve defects in virtue of supporting Schwann cell adherence, expansion and migration. Therefore the SF graft is a promising alternative to classical autografts for peripheral nerve repair.

  2. A novel artificial nerve graft for repairing long-distance sciatic nerve defects: a self-assembling peptide nanofiber scaffold-containing poly(lactic-co-glycolic acid) conduit.

    Science.gov (United States)

    Wang, Xianghai; Pan, Mengjie; Wen, Jinkun; Tang, Yinjuan; Hamilton, Audra D; Li, Yuanyuan; Qian, Changhui; Liu, Zhongying; Wu, Wutian; Guo, Jiasong

    2014-12-15

    In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold (SAPNS)-containing poly(lactic-co-glycolic acid) (PLGA) conduit (SPC) and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myofiber diameter in the target muscle. These findings suggest that the novel artificial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury. PMID:25657734

  3. A novel artificial nerve graft for repairing long-distance sciatic nerve defects: a self-assembling peptide nanofiber scaffold-containing poly(lactic-co-glycolic acid) conduit

    OpenAIRE

    Wang, Xianghai; Pan, Mengjie; Wen, Jinkun; Tang, Yinjuan; Hamilton, Audra D.; Li, Yuanyuan; Qian, Changhui; Liu, Zhongying; Wu, Wutian; Guo, Jiasong

    2014-01-01

    In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold (SAPNS)-containing poly(lactic-co-glycolic acid) (PLGA) conduit (SPC) and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of...

  4. An experimental study of nerve bypass graft

    Institute of Scientific and Technical Information of China (English)

    XU Jie; LI Xue-shi

    2008-01-01

    Objective: To study the use of a nerve "bypass" graft as a possible alternative to neurolysis or segmental resection with interposition grafting in the treatment of neuroma-in-continuity. Methods: A sciatic nerve crush injury model was established in the Sprague-Dawley rat by compression with a straight hemostatic forceps. Epineurial windows were created proximal and distal to the injury site. An 8-mm segment of radial nerve was harvested and coaptated to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Nerve conduction studies were performed over an 8-week period. Sciatic nerves were then harvested and studied under transmission electron microscopy. Myelinated axon counts were obtained. Results: Nerve conduction velocity was significantly faster in the bypass group than in the control group at 8 weeks (63.57 m/s±5.83 m/s vs. 54.88 m/s±4.79m/s, P<0.01). Myelinated axon counts in distal segments were found more in the experimental sciatic nerve than in the control sciatic nerve. Significant axonal growth was noted in the bypass nerve segment itself. Conclusion: Nerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve.

  5. Histological observation on acellular nerve grafts co-cultured with Schwann cells for repairing defects of the sciatic nerve

    Institute of Scientific and Technical Information of China (English)

    Xiaohong Sun; Jiangyi Tian; Xiaojie Tong; Xu Zhang; Zheng He

    2006-01-01

    BACKGROUND: Animal experiments and clinical studies about tissue engineering method applied to repair nerve injury mainly focus on seeking ideal artificial nerve grafts, nerve conduit and seed cells. Autologous nerve, allogeneic nerve and xenogeneic nerve are used to bridge nerve defects, it is one of the methods to promote the repair of nerve injury by culturing and growing Schwann cells, which can secrete various neurotrophic factor activities, in the grafts.OBJECTIVE: To observe the effect of acellular nerve grafts co-cultured with Schwann cells in repairing defects of sciatic nerve.DESIGN: An observational comparative study.SETTING: Tissue Engineering Laboratory of China Medical University.MATERIALS: The experiment was carried out in the Tissue Engineering Laboratory of China Medical University between April 2004 and April 2005. Forty neonatal Sprague-Dawley rats of 5-8 days (either males or females) and 24 male Wistar rats of 180-220 g were provided by the experimental animal center of China Medical University.METHODS: ① Culture of Schwann cells: The bilateral sciatic nerves and branchial plexus were isolated from the 40 neonatal SD rats. The sciatic nerves were enzymatically digested with collagenase and dispase, isolatd, purified and cultured with the method of speed-difference adhersion, and identified with the SABC immunohistochemical method. ② Model establishment: In vitro Schwann cells were microinjected into 10-mm long acellular nerve grafts repairing a surgically created gap in the rat sciatic nerve.According to the different grafted methods, the animals were randomly divided into three groups: autografts (n=8), acellular nerve grafts (n=8), or acellular nerve grafts with Schwann cells (n=8). ③ The regenerated nerve fiber number and average diameter of myeline sheath after culture were statistically anlayzed.MAIN OUTCOME MEASURES: ① The regenerated nerve ultrastructure, total number and density of myelinated nerve fibers, and the thickness of

  6. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    OpenAIRE

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft com...

  7. Combination of Acellular Nerve Graft and Schwann Cells-Like Cells for Rat Sciatic Nerve Regeneration

    OpenAIRE

    Songtao Gao; Yan Zheng; Qiqing Cai; Zhansheng Deng; Weitao Yao; Jiaqiang Wang; Xin Wang; Peng Zhang

    2014-01-01

    Objective. To investigate the effect of tissue engineering nerve on repair of rat sciatic nerve defect. Methods. Forty-five rats with defective sciatic nerve were randomly divided into three groups. Rats in group A were repaired by acellular nerve grafts only. Rats in group B were repaired by tissue engineering nerve. In group C, rats were repaired by autogenous nerve grafts. After six and twelve weeks, sciatic nerve functional index (SFI), neural electrophysiology (NEP), histological and tra...

  8. Small parietal thrombi in artificial bypass grafts

    International Nuclear Information System (INIS)

    During the last five years, 51 femoro-popliteal polytrafluoroethylene grafts were implanted in patients in the Second Surgical University Clinic, Vienna. In four of these patients an angiogram performed shortly after operation showed numerous small parietal thrombi on the artificial graft, a review of the literature has not shown any similar reports. The clinical importance and consequences of this observation are discussed. (orig.)

  9. Detergent-free Decellularized Nerve Grafts for Long-gap Peripheral Nerve Reconstruction

    Directory of Open Access Journals (Sweden)

    Srikanth Vasudevan, PhD

    2014-08-01

    Conclusions: This study describes a detergent-free nerve decellularization technique for reconstruction of long-gap nerve injuries. We compared DFD grafts with an established detergent processing technique and found that DFD nerve grafts are successful in promoting regeneration across long-gap peripheral nerve defects as an alternative to existing strategies.

  10. Functional Outcomes of Multiple Sural Nerve Grafts for Facial Nerve Defects after Tumor-Ablative Surgery

    OpenAIRE

    Lee, Myung Chul; Kim, Dae Hee; Jeon, Yeo Reum; Rah, Dong Kyun; Lew, Dae Hyun; Choi, Eun Chang; Lee, Won Jai

    2015-01-01

    Background Functional restoration of the facial expression is necessary after facial nerve resection to treat head and neck tumors. This study was conducted to evaluate the functional outcomes of patients who underwent facial nerve cable grafting immediately after tumor resection. Methods Patients who underwent cable grafting from April 2007 to August 2011 were reviewed, in which a harvested branch of the sural nerve was grafted onto each facial nerve division. Twelve patients underwent facia...

  11. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair.

    Science.gov (United States)

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-07-15

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  12. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    Institute of Scientific and Technical Information of China (English)

    Yanru Zhang; Hui Zhang; Kaka Katiella; Wenhua Huang

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune re-jection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regenera-tion. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anasto-mosis, but superior to chemically extracted acellular allogeneic nerve bridging alone.

  13. Comparison of nerve graft integration after segmentar resection versus epineural burying in crushed rat sciatic nerves

    Directory of Open Access Journals (Sweden)

    Cunha Marco Túlio Rodrigues da

    1997-01-01

    Full Text Available The aim of the present paper is to compare and correlate the take of nerve segments in a severely crushed nerve. Forty adult Wistar rats had their right sciatic nerve by a "Péan-Murphy" forceps for 40 minutes. In Group 1 (n=20, a segmentar serection in the crushed sciatic nerve was made. A sural nerve segment from the opposite hindpaw was placed in the gap. In Group 2 (n=20, a lontudinal insision in the epineurium of the lesioned sciatic nerve was made. A sural nerve segment was buried underneath the epineurium. The crushed sciatic nerves undergone Wallerian degeneration and endoneurial fibrosis. Sciatic nerves from Group 2 had significant better histological aspects than those from Group 1. Sural nerve grafts presented better degrees of regeneration than crushed sciatic nerves. Sural nerve grafts from Group 2 (burying method integrated as well as those from Group 1 (segmentar resection.

  14. Effect of oblique nerve grafting on peripheral nerve regeneration in rats.

    Science.gov (United States)

    Kotulska, Katarzyna; Marcol, Wiesław; Larysz-Brysz, Magdalena; Tendera, Zofia; Malinowska-Kołodziej, Izabela; Slusarczyk, Wojciech; Jedrzejowska-Szypułka, Halina; Lewin-Kowalik, Joanna

    2006-01-01

    Current methods of peripheral nerve repair are to rejoin cut nerve stumps directly or to bridge large gaps with autologous nerve grafts. In both cases the surface of nerve stump endings is typically cut perpendicularly to the long axis of the nerve. The outcome of such operations, however, is still not satisfactory. In this study, we examine the effect of oblique nerve cutting and grafting on morphological as well as functional features of regeneration. In adult rats, sciatic nerve was cut and rejoined either directly or using an autologous graft, at 90 degrees or 30 degrees angle. Functional regeneration was assessed by walking track analysis during 12-week follow-up. Afterwards muscle weight was measured and histological studies were performed. The latter included nerve fibers and Schwann cells counting, as well as visualization of scar formation and epineural fibrosis. Nerves cut obliquely and rejoined showed better functional recovery than perpendicularly transected. Similar effect was observed after oblique grafting when compared to perpendicular one. Numbers of nerve fibers growing into the distal stump of the nerve as well as the number of Schwann cells were significantly higher in obliquely than in perpendicularly operated nerves. Moreover, growing axons were arranged more regularly following oblique treatment. These data indicate that joining or grafting the nerve stumps at acute angle is a more profitable method of nerve repair than the standard procedure performed at right angle. PMID:17066410

  15. Biocelulose grafts: the future in artificial vascular grafts? preliminar results

    OpenAIRE

    Silva, Ivone; Loureiro, Luís; Araújo, Anabela; Alexandre F. Leitão; Faria, Miguel; Gama, F. M.

    2013-01-01

    Introduction: Vascular grafts, autogenous or artificial, are used to replace, bypass or maintain function of occluded, damaged, or diseased blood vessels of small, medium and large diameter. Vascular prostheses may be manufactured from synthetic, biological or biosynthetic materials. To our knowledge this is the first study to look at the hemocompatibility of bacterial cellulose membrane reinforced by the presence of polyvinyl alcohol. Materials/ methods The first aim of ...

  16. Biofabrication and testing of a fully cellular nerve graft

    International Nuclear Information System (INIS)

    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)

  17. Median Nerve Repair with Autologous Sciatic Nerve Graft: A Case Report

    OpenAIRE

    Ragel, Brian T.; Park, Gregory C.; Sid Brevard

    2011-01-01

    Background. Peripheral nerve injury treatment options are limited to primary nerve repair, nerve grafting, and tendon transfers. In this case, a large suitable donor site was easily accessible and delayed grafting was indicative of poor prognosis. Case Description. A 25-year-old soldier presented to a military hospital in Afghanistan following a roadside bomb attack. The patient had a medial shrapnel wound in the bicipital groove with a cool pulseless hand and catastrophic lower extremity inj...

  18. Combination of Acellular Nerve Graft and Schwann Cells-Like Cells for Rat Sciatic Nerve Regeneration

    Directory of Open Access Journals (Sweden)

    Songtao Gao

    2014-01-01

    Full Text Available Objective. To investigate the effect of tissue engineering nerve on repair of rat sciatic nerve defect. Methods. Forty-five rats with defective sciatic nerve were randomly divided into three groups. Rats in group A were repaired by acellular nerve grafts only. Rats in group B were repaired by tissue engineering nerve. In group C, rats were repaired by autogenous nerve grafts. After six and twelve weeks, sciatic nerve functional index (SFI, neural electrophysiology (NEP, histological and transmission electron microscope observation, recovery ratio of wet weight of gastrocnemius muscle, regenerated myelinated nerve fibers number, nerve fiber diameter, and thickness of the myelin sheath were measured to assess the effect. Results. After six and twelve weeks, the recovery ratio of SFI and wet weight of gastrocnemius muscle, NEP, and the result of regenerated myelinated nerve fibers in groups B and C were superior to that of group A (P0.05. Conclusion. The tissue engineering nerve composed of acellular allogenic nerve scaffold and Schwann cells-like cells can effectively repair the nerve defect in rats and its effect was similar to that of the autogenous nerve grafts.

  19. Use of superficial peroneal nerve graft for treating peripheral nerve injuries

    Directory of Open Access Journals (Sweden)

    Samuel Ribak

    2016-02-01

    Full Text Available ABSTRACT OBJECTIVE: To evaluate the clinical results from treating chronic peripheral nerve injuries using the superficial peroneal nerve as a graft donor source. METHODS: This was a study on eleven patients with peripheral nerve injuries in the upper limbs that were treated with grafts from the sensitive branch of the superficial peroneal nerve. The mean time interval between the dates of the injury and surgery was 93 days. The ulnar nerve was injured in eight cases and the median nerve in six. There were three cases of injury to both nerves. In the surgery, a longitudinal incision was made on the anterolateral face of the ankle, thus viewing the superficial peroneal nerve, which was located anteriorly to the extensor digitorum longus muscle. Proximally, the deep fascia between the extensor digitorum longus and the peroneal longus muscles was dissected. Next, the motor branch of the short peroneal muscle (one of the branches of the superficial peroneal nerve was identified. The proximal limit of the sensitive branch was found at this point. RESULTS: The average space between the nerve stumps was 3.8 cm. The average length of the grafts was 16.44 cm. The number of segments used was two to four cables. In evaluating the recovery of sensitivity, 27.2% evolved to S2+, 54.5% to S3 and 18.1% to S3+. Regarding motor recovery, 72.7% presented grade 4 and 27.2% grade 3. There was no motor deficit in the donor area. A sensitive deficit in the lateral dorsal region of the ankle and the dorsal region of the foot was observed. None of the patients presented complaints in relation to walking. CONCLUSIONS: Use of the superficial peroneal nerve as a graft source for treating peripheral nerve injuries is safe and provides good clinical results similar to those from other nerve graft sources.

  20. Use of superficial peroneal nerve graft for treating peripheral nerve injuries☆

    Science.gov (United States)

    Ribak, Samuel; da Silva Filho, Paulo Roberto Ferreira; Tietzmann, Alexandre; Hirata, Helton Hiroshi; de Mattos, Carlos Augusto; da Gama, Sérgio Augusto Machado

    2016-01-01

    Objective To evaluate the clinical results from treating chronic peripheral nerve injuries using the superficial peroneal nerve as a graft donor source. Methods This was a study on eleven patients with peripheral nerve injuries in the upper limbs that were treated with grafts from the sensitive branch of the superficial peroneal nerve. The mean time interval between the dates of the injury and surgery was 93 days. The ulnar nerve was injured in eight cases and the median nerve in six. There were three cases of injury to both nerves. In the surgery, a longitudinal incision was made on the anterolateral face of the ankle, thus viewing the superficial peroneal nerve, which was located anteriorly to the extensor digitorum longus muscle. Proximally, the deep fascia between the extensor digitorum longus and the peroneal longus muscles was dissected. Next, the motor branch of the short peroneal muscle (one of the branches of the superficial peroneal nerve) was identified. The proximal limit of the sensitive branch was found at this point. Results The average space between the nerve stumps was 3.8 cm. The average length of the grafts was 16.44 cm. The number of segments used was two to four cables. In evaluating the recovery of sensitivity, 27.2% evolved to S2+, 54.5% to S3 and 18.1% to S3+. Regarding motor recovery, 72.7% presented grade 4 and 27.2% grade 3. There was no motor deficit in the donor area. A sensitive deficit in the lateral dorsal region of the ankle and the dorsal region of the foot was observed. None of the patients presented complaints in relation to walking. Conclusions Use of the superficial peroneal nerve as a graft source for treating peripheral nerve injuries is safe and provides good clinical results similar to those from other nerve graft sources. PMID:26962502

  1. Comparison of divided sciatic nerve growth within dermis, venous and nerve graft conduit in rat

    Science.gov (United States)

    Fatemi, Mohammad Javad; Foroutan, Kamal Seyed; Ashtiani, Abass Kazemi; Mansoori, Maryam Jafari; Vaghardoost, Reza; Pedram, Sepehr; Hosseinpolli, Aidin; Rajabi, Fatemeh; Mousavi, Seyed Jaber

    2010-01-01

    BACKGROUND: Considering the common origin of skin and peripheral nervous system, a tube of dermal layer of skin hypothetically can be an ideal conduit for nerve reconstruction. An experimental study performed to evaluate the nerve regeneration of efficacy into a dermal tube. METHODS: Sixty male Wistar rats were used. A 10 mm gap was produced in right sciatic nerves. In group A the autogenous nerve grafts were used to bridge the defects. In group B vein conduit were use to reconstruct the gaps. In group C dermal tube were used to bridge the defects. Morphologic studies were carried out after 3 month. RESULTS: The density of nerve fibers was significantly higher in autogenous nerve graft group. The efficacy of nerve growth into the dermal tube group was significantly poor in comparison to other groups. CONCLUSIONS: In the present study, dermis was used as the nerve conduit for the first time. This study indicates that the dermal tube is not a suitable conduit for nerve regeneration till further studies to resolve the problems before clinical application. PMID:21526083

  2. Platelet-rich plasma-induced bone marrow mesenchymal stem cells versus autologous nerve grafting for sciatic nerve repair

    Institute of Scientific and Technical Information of China (English)

    Changsuo Xia; Yajuan Li; Wen Cao; Zhaohua Yu

    2010-01-01

    Autologous nerve grafting is the gold standard of peripheral nerve repair.We previously showed that autologous platelet-rich plasma(PRP)contains high concentrations of growth factors and can induce in vitro cultured bone marrow mesenchymal stem cells(BMSCs)to differentiate into Schwann cells.Here we used PRP-induced BMSCs combined with chemically extracted acellular nerves to repair sciatic nerve defects and compared the effect with autologous nerve grafting.The BMSCs and chemically extracted acellular nerve promoted target muscle wet weight restoration,motor nerve conduction velocity,and axonal and myelin sheath regeneration,with similar effectiveness to autologous nerve grafting.This finding suggests that PRP induced BMSCs can be used to repair peripheral nerve defects.

  3. The vascularized sural nerve graft based on a peroneal artery perforator for reconstruction of the inferior alveolar nerve defect.

    Science.gov (United States)

    Hayashida, Kenji; Hiroto, Saijo; Morooka, Shin; Kuwabara, Kaoru; Fujioka, Masaki

    2015-03-01

    The sural nerve has been described for nerve reconstruction of the maxillofacial region since it provides many advantages. We report a case of a vascularized sural nerve graft based on a peroneal artery perforator for immediate reconstruction after the removal of intraosseous neuroma originating in the inferior alveolar nerve. The patient had a neuroma caused by iatrogenic injury to the inferior alveolar nerve. A 4-cm long neuroma existed in the inferior alveolar nerve and was resected. A peroneal perforator was chosen as the pedicle of the vascularized sural nerve graft for the nerve gap. The graft including the skin paddle for monitoring the perfusion supplied by this perforator was transferred to the lesion. The nerve gap between the two stumps of the inferior alveolar nerve was repaired using the 6-cm long vascularized sural nerve. The perforator of the peroneal artery was anastomosed to the branch of the facial artery in a perforator-to-perforator fashion. There was no need to sacrifice any main arteries. The skin paddle with 1 cm × 3 cm in size was inset into the incised medial neck. Perceptual function tests with a Semmes-Weinstein pressure esthesiometer and two-point discrimination in the lower lip and chin at 10 months after surgery showed recovery almost to the level of the normal side. This free vascularized sural nerve graft based on a peroneal artery perforator may be a good alternative for reconstruction of inferior alveolar nerve defects. PMID:25346479

  4. Regeneration of the Nerves in the Aerial Cavity with an Artificial Nerve Conduit -Reconstruction of Chorda Tympani Nerve Gaps-

    OpenAIRE

    Yamanaka, Toshiaki; Hosoi, Hiroshi; Murai, Takayuki; Kobayashi, Takehiko; Inada, Yuji; Nakamura, Tatsuo

    2014-01-01

    Objectives/Hypothesis Due to its anatomical features, the chorda tympani nerve (CTN) is sometimes sacrificed during middle ear surgery, resulting in taste dysfunction. We examined the effect of placing an artificial nerve conduit, a polyglycolic acid (PGA)-collagen tube, across the gap in the section of the resected chorda tympani nerve (CTN) running through the tympanic cavity. Methods The CTN was reconstructed with a PGA-collagen tube in three patients with taste disturbance who underwent C...

  5. Preparation of acellular nerve grafts with triton X-100

    Institute of Scientific and Technical Information of China (English)

    Jinbao Han; Juwen Chen; Baohui Zhao; Jichun Zhang; Dehu Tian; Jiuhui Han

    2006-01-01

    BACKGROUND: The source of nerve allograft enriches.We may choose expediently nerve allograft to repair injured nerve and the structure of choice nerve homlolgy or similar with the injured nerve,but the immunological rejiction limits the climical application of nerve allograft.The ideal substitute of autograft never is reaearching.OBJECTIVE: In this experiment,Triton X-100 was used to extract the Schwann cells and myelin sheaths of allograft nerve and obtain the inartiflcial and eliminated antigenicity nerve-transplanter(nerve grafts).DESIGN: Controlled experiment.SETTING: Department of Hand Surgery,the Third Affiliated Hospital of Hebei Medical University;Second Department of Orthopedics,Fourth Center Hospital of Tianjin.MATERIALS: Thirty heath New Zealand big ear white rabbit .of either sex(gender).weighing 2000-3000 g,were provided by the Center of Experimental Animal of Hebei Medical University.Triton X-100 was offered by SIGMA Company.METHODS: The experiment was carried out at the Central Laboratory of the Third Affiliated Hospital of Hebei Medical University from December 2003 to December 2004.Sixty pieces of sciatic nerves.10-mm-long nerve segment,which were taken from 30 rabbits,were incised.They were randomly divided into chemical extraction group(n=50)and control group(n=10).In the chemical extraction groups,the nerves were put into 3% Triton X-100 solution.They were treated with Triton X-100 for 12 hours,24 hours,48 hours,96 hours and 1 week.respectively.They were examined in every period.The control groups did not treated with anything. ①Respectively two segments of nerve by 2 mm length were taken from each nerve in the every periods.②The laminin immunohistochemical stained sections were performed with image acquisition and analyzed with multicolor pathological image analysis system.Measured the laminin antibody reaction part of each section and computed laminin average gray degrees of the unit area.All dates were analyzed by SPSS 10.0 software

  6. Tissue specificity in rat peripheral nerve regeneration through combined skeletal muscle and vein conduit grafts.

    Science.gov (United States)

    Tos, P; Battiston, B; Geuna, S; Giacobini-Robecchi, M G; Hill, M A; Lanzetta, M; Owen, E R

    2000-01-01

    Diffusible factors from the distal stumps of transected peripheral nerves exert a neurotropic effect on regenerating nerves in vivo (specificity). This morphological study was designed to investigate the existence of tissue specificity in peripheral nerve fiber regeneration through a graft of vein filled with fresh skeletal muscle. This tubulization technique demonstrated experimental and clinical results similar to those obtained with traditional autologous nerve grafts. Specifically, we used Y-shaped grafts to assess the orientation pattern of regenerating axons in the distal stump tissue. Animal models were divided into four experimental groups. The proximal part of the Y-shaped conduit was sutured to a severed tibial nerve in all experiments. The two distal stumps were sutured to different targets: group A to two intact nerves (tibial and peroneal), group B to an intact nerve and an unvascularized tendon, group C to an intact nerve and a vascularized tendon, and group D to a nerve graft and an unvascularized tendon. Morphological evaluation by light and electron microscopy was conducted in the distal forks of the Y-shaped tube. Data showed that almost all regenerating nerve fibers spontaneously oriented towards the nerve tissue (attached or not to the peripheral innervation field), showing a good morphological pattern of regeneration in both the early and late phases of regeneration. When the distal choice was represented by a tendon (vascularized or not), very few nerve fibers were detected in the corresponding distal fork of the Y-shaped graft. These results show that, using the muscle-vein-combined grafting technique, regenerating axons are able to correctly grow and orientate within the basement membranes of the graft guided by the neurotropic lure of the distal nerve stump. PMID:10702739

  7. Autogenous standard versus inside-out vein graft to repair facial nerve in rabbits

    Institute of Scientific and Technical Information of China (English)

    TANG Jie; WANG Xue-mei; HU Jing; LUO En; QI Meng-chun

    2008-01-01

    To evaluate autogenous vein grafts and inside-out vein grafts as conduits for the defects repair in the rabbit facial nerves.Methods:The 10 mm segments of buccal division of facial nerve were transected for 48 rabbits in this study.Then the gaps were immediately repaired by autogenous vein grafts or inside-out vein grafts in different groups. All the animals underwent the whisker movement test and electrophysiologic test during the following 16 weeks at different time points postoperatively. Subsequently,the histological examination was performed to observe the facial nerve regeneration morphologically.Results:At 8 weeks after operation,the facial nerve regeneration has significant difference between the experimental group and the control group in electrophysiologic test and histological observation. However,at the end of this study,16 weeks after operation,there was no significant difference between inside-out vein grafts and standard vein grafts in enhancing peripheral nerve regeneration.Conclusion:This study suggest that both kinds of vein grafts play positive roles in facial nerve regeneration after being repaired immediately,but the autogenous inside-out vein grafts might accelerate and facilitate axonal regeneration as compared with control.

  8. Successful delayed reconstruction of common peroneal neuroma-in-continuity using sural nerve graft.

    Science.gov (United States)

    Reichl, Heike; Ensat, Florian; Dellon, A Lee; Wechselberger, Gottfried

    2013-02-01

    Injuries of the common peroneal nerve (CPN) are frequent and associated with poor motor outcomes. So far, the opinion is held, that nerve reconstruction is reasonable and indicated up to 6 months after injury. We describe successful sural nerve interposition grafting in a patient with neuroma-in-continuity formation of the CPN, presenting with foot drop, 13 months after injury. Due to this positive result, we think nerve grafting in neuroma-in-continuity lesions of the CPN should be contemplated in patients with foot drop even more than one year after injury. PMID:23180561

  9. Nerve grafting and nerve suture in postoperative facial palsies: A report of 69 cases

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    Karsten Kettel

    1954-12-01

    Full Text Available Since 1939, 260 patients with a peripheral facial palsy have been operated on by me according to Ballance and Duel, and in 61 cases nerve grafting, in 8 nerve suture was performed; 66 of the patients have been re-examined by me, 2 have been operated upon lately and one could not be traced. If a complete facial palsy arises in direct conjunction with surgery or accident the repair should, if possible, be undertaken without delay; if it occurs after an interval of freedom and the continuity of the nerve is unbroken the prognosis on the whole is good. The technique is discussed and the importance of the after-treatment is stressed. The results may be divided into two groups according to the conditions for and the proceeding of the repair, illustrated in tables 1 and 2. Among 52 cases, in which no degeneration of the musc'es had taken place and in which the operation was successfully performed a clinically satisfactory result was obtained in 47 patients. If these conditions are not fulfilled the prospect of a satisfactory result is a priori poor. It must be born in mind that not even the most successful operation will be able to restore function completely.

  10. Vascularized Nerve Bypass Graft: A Case Report of an Additional Treatment for Poor Sensory Recovery.

    Science.gov (United States)

    Usami, Satoshi; Tanaka, Kentaro; Ohkubo, Alisa; Okazaki, Mutsumi

    2016-04-01

    End-to-side neurorrhaphy has proven effective in basic research and in clinical application. One of the methods of end-to-side neurorrhaphy, nerve bypass technique, has been reported and axon regeneration has been proven. In clinical application, the utility of the nerve bypass technique has been revealed in some cases; however, these bypasses were performed using nonvascularized nerves. We initially used the vascularized nerve bypass graft technique with the sural nerve as a secondary clinical procedure after median nerve injury in a 61-year-old patient and achieved motor and sensory nerve regeneration, as supported by a nerve conduction study and clinical sensory test. This technique has the potential to become one of the choices for salvage procedure of severe nerve injury. PMID:27200248

  11. Autologous nerve graft repair of different degrees of sciatic nerve defect: stress and displacement at the anastomosis in a three-dimensional fnite element simulation model

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    Cheng-dong Piao

    2015-01-01

    Full Text Available In the repair of peripheral nerve injury using autologous or synthetic nerve grafting, the magnitude of tensile forces at the anastomosis affects its response to physiological stress and the ultimate success of the treatment. One-dimensional stretching is commonly used to measure changes in tensile stress and strain however, the accuracy of this simple method is limited. Therefore, in the present study, we established three-dimensional finite element models of sciatic nerve defects repaired by autologous nerve grafts. Using PRO E 5.0 finite element simulation software, we calculated the maximum stress and displacement of an anastomosis under a 5 N load in 10-, 20-, 30-, 40-mm long autologous nerve grafts. We found that maximum displacement increased with graft length, consistent with specimen force. These findings indicate that three-dimensional finite element simulation is a feasible method for analyzing stress and displacement at the anastomosis after autologous nerve grafting.

  12. Repairing peripheral nerve defects with tissue engineered artificial nerves in rats

    Institute of Scientific and Technical Information of China (English)

    WEI Ai-lin; LIU Shi-qing; TAO Hai-ying; PENG Hao

    2008-01-01

    statistical difference was found between Group B and Group D. Obvious compound muscle ( or motor) action potential ( CMAP) could be evoked in Group A and Group C,but the evoked amplitude was very low in Group B and Group D. The axons of regenerated nerves penetrated through the whole graft in Group A and Group C, and partly penetrated through the graft in Group B, but did not penetrate in Group D. The two tips of the separated sciatic nerves of Groups A , B , and C were connected together, without formation of neuroma. But those of Group D were not connected together and neuroma formed in 6 rats.Conclusions: Tissue engineered nerves can be used for repairing long defects of the peripheral nerves of rats and ideal repairing effects can be obtained.

  13. Regeneration of the nerves in the aerial cavity with an artificial nerve conduit --reconstruction of chorda tympani nerve gaps-.

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    Toshiaki Yamanaka

    Full Text Available Due to its anatomical features, the chorda tympani nerve (CTN is sometimes sacrificed during middle ear surgery, resulting in taste dysfunction. We examined the effect of placing an artificial nerve conduit, a polyglycolic acid (PGA-collagen tube, across the gap in the section of the resected chorda tympani nerve (CTN running through the tympanic cavity.The CTN was reconstructed with a PGA-collagen tube in three patients with taste disturbance who underwent CTN resection. To evaluate the effect of the reconstruction procedure on the patients' gustatory function, we measured the patients' electrogustometry (EGM thresholds. The patients were followed-up for at least two years.Gustatory function was completely restored in all of the patients after the reconstruction. The patients' EGM thresholds exhibited early improvements within one to two weeks and had returned to their normal ranges within three months. They subsequently remained stable throughout the two-year follow-up period. In a patient who underwent a second surgical procedure, it was found that the PGA-collagen tube used in the first surgical procedure had been absorbed and replaced by new CTN fibers with blood vessels on their surfaces.These results suggest that reconstruction of the CTN with an artificial nerve conduit, a PGA-collagen tube, allows functional and morphological regeneration of the nerve and facilitates the recovery of taste function. PGA-collagen tubes might be useful for repairing CTNs that are resected during middle ear surgery. Further research is required to confirm these preliminary results although this is the first report to describe the successful regeneration of a nerve running through an aerial space.

  14. 带蒂筋膜管的耳大神经移植治疗面神经缺失性损伤%Treating defective damage of facial nerve with great auricular nerve grafting covered by pediculated fascial tube

    Institute of Scientific and Technical Information of China (English)

    蒋立新

    2002-01-01

    Objective To study the curative effect of grafting great auricular nerve with pediculated fascial tube in defective damage of facial nerve.Method All the patients in the study were treated by grafting great auricular nerve which was covered by pediculated fascial tube near facial nerve trunk.Result The 3 otogenic fascial paralysis patients had grade III recovery of facial nerve function(30% ~ 38% ) 2.0 to 2.5 years after the nerve grafting operation; 2 post- traumatic facial paralysis patients had grade II recovery of facial nerve function (69% ~ 71% ) 2.5 to 3.5 years after the nerve grafting operation.Conclusion The grafting of pediculated fascial tube surrounded great auricular nerve can provide a biological environment with excellent blood supply for the plerosis and regeneration of nerves and can accelerate the functional recovery of nerves after the nerve grafting.

  15. AB023. Penile augmentation surgery: characteristics of artificial graft material and preoperative preparation

    OpenAIRE

    Lee, Woong Hee

    2015-01-01

    Penile augmentation surgical procedure includes diverse graft materials such as artificial collagen material as well as dermo-fat graft. Important factors of postoperative satisfaction are natural appearance of genitalia at the flaccid state and minimal resorption of graft volume. Artificial collagen materials and acellular dermal matrix are available for surgical procedure with variable size. History of penile augmentation surgery: Pediatric penile surgical procedure for lengthening and reco...

  16. Functional recovery of sciatic nerve through inside-out vein graft in rats

    Institute of Scientific and Technical Information of China (English)

    Rahim Mohammadi; Saeed Azizi; Nowruz Delirezh; Rahim Hobbenaghi; Keyvan Amini

    2011-01-01

    Objective: Present study aimed at further comprehensive functional, histomorphometrical and immunohistochemical assessment of peripheral nerve regeneration using rat sciatic nerve transection model.Methods: The 10-mm rat sciatic nerve gap was created in rats. In control group nerve stumps were sutured to adjacent muscle and in treatment group the gap was bridged using an inside-out vein graft. In sham-operated group the nerve was manipulated and left intact. All animals underwent walking track analysis test 4, 8, and 12 weeks after surgery.Subsequently, muscle mass measurement was performed to assess reenervation, histological examination to observe the sciatic nerve regeneration morphologically and immunohistochemistry to detect Schwann cells using anti S-100. Results were analyzed using a factorial ANOVA with two between-subjects factors. Bonferroni test for pairwise comparisons was used to examine the effect of treatments.Results: Functional analysis ofmyelinated nerve fibers showed that nerve function improved significantly in the time course in treatment group. However, quantitative morphometrical analysis of myelinated nerve fibers showed that there was no significant difference between 8 and 12 weeks in treatment group. Muscle weight ratio was bigger and weight loss of the gastrocnemius muscle was ameliorated by inside-out vein grafting. The position of positive immunohistochemical reactions further implied that regenerated axons and Schwann cell-like cells existed after vein grafting was performed, and was accompanied by the process of myelination and structural recovery of regenerated nerves.Conclusion: Functional analysis of peripheral nerve repair is far more reliable than quantitative morphometrical analysis

  17. Sensory reinnervation of muscle spindles after repair of tibial nerve defects using autogenous vein grafts

    Institute of Scientific and Technical Information of China (English)

    Youwang Pang; Qingnan Hong; Jinan Zheng

    2014-01-01

    Motor reinnervation after repair of tibial nerve defects using autologous vein grafts in rats has previously been reported, but sensory reinnervation after the same repair has not been fully investigated. In this study, partial sensory reinnervation of muscle spindles was observed after repair of 10-mm left tibial nerve defects using autologous vein grafts with end-to-end anasto-mosis in rats, and functional recovery was conifrmed by electrophysiological studies. There were no signiifcant differences in the number, size, or electrophysiological function of reinnervated muscle spindles between the two experimental groups. These ifndings suggest that repair of short nerve defects with autologous vein grafts provides comparable results to immediate end-to-end anastomosis in terms of sensory reinnervation of muscle spindles.

  18. Partial epineural burying of nerve grafts with different sizes next to or distant from neurorrhaphy?s site: histological and electrophysiological studies in rat sciatic nerves

    Directory of Open Access Journals (Sweden)

    Cunha Marco Túlio Rodrigues da

    2001-01-01

    Full Text Available The aim of the present study was to compare and correlate histologically and electromyographically the effects of partial epineural burying of sural nerve segments in sectioned and sutured rat sciatic nerves. Sixty adult male Wistar rats were operated on 3 groups: Group 1, sural nerve graft, 9mm long, placed next to neurorrhaphy; Group 2, sural nerve graft, 9mm long, buryied 10mm distant from neurorrhaphy; Group 3, sural nerve graft, 18mm long, set next to neurorrhaphy. The morphological features were examined at light microscope after 3 months in 45 rats. The elements observed were: vascularization, vacuoles in nerve fibers, mastocytes and inflammatory infiltrate. The morphometry was made after 6 months in 15 rats from Group 1, 2 and 3, measuring external nerve fiber diameters and counting myelinated nerve fibers/mm². The electrophysiological study was perfomed after 6 months, registering maximum amplitude and frequency of EMG pontentials, at rest, in extensor digitorum longus muscle. Group 3 rats presented sciatic nerves better conserved morphologically and mean external nerve fiber diameters greater than those from Groups 1 and 2. There were no significant differences in density of nerve fibers/mm², and in the electrophysiological study in rats from Group 1, 2 and 3. The epineural burying of sural nerve grafts with greater length and placed next to the neurorrhaphy?s site had a significantly better regeneration of the histological features than the smaller ones distant from neurorrhaphy.

  19. Comparison of nerve graft integration after segmentar resection versus epineural burying in crushed rat sciatic nerves

    OpenAIRE

    Cunha Marco Túlio Rodrigues da; Silva Alcino Lázaro da; Fenelon Sheila Bernardino

    1997-01-01

    The aim of the present paper is to compare and correlate the take of nerve segments in a severely crushed nerve. Forty adult Wistar rats had their right sciatic nerve by a "Péan-Murphy" forceps for 40 minutes. In Group 1 (n=20), a segmentar serection in the crushed sciatic nerve was made. A sural nerve segment from the opposite hindpaw was placed in the gap. In Group 2 (n=20), a lontudinal insision in the epineurium of the lesioned sciatic nerve was made. A sural nerve segment was buried unde...

  20. Two-Stage Nerve Graft in Severe Scar: A Time-Course Study in a Rat Model

    Directory of Open Access Journals (Sweden)

    Shayan Zadegan

    2015-04-01

    According to the EPT and WRL, the two-stage nerve graft showed significant improvement (P=0.020 and P =0.017 respectively. The TOA showed no significant difference between the two groups. The total vascular index was significantly higher in the two-stage nerve graft group (P

  1. Effects of Adrenal Medulla and Sciatic Nerve Co-Grafts in Rats with Unilateral Substantia Nigra Lesions

    OpenAIRE

    Freed, William J.; Willingham, George; Heim, Robert

    1992-01-01

    Major limitations of adrenal medulla transplantation in animal models of Parkinson's disease have been the relatively small behavioral effects and the poor or inconsistent graft survival. Transplantation of fragments of sural nerve in combination with adrenal medulla has been reported to increase the survival of chromaffin cells in adrenal medulla grafts in primates. In the present study, the possibility was tested that peripheral nerve co-grafts would increase the functional effects of adren...

  2. Two-Stage Nerve Graft in Severe Scar: A Time-Course Study in a Rat Model

    OpenAIRE

    Shayan Zadegan; Masoumeh Firouzi; Mohammad Hossein Nabian; Leila Zanjani; Ahmad Ashtiani; Reza Shahryar Kamrani

    2015-01-01

    Background: Peripheral nerve repair outcomes are suboptimal in the presence of severe soft tissue injury and excessive scarring paralleling the process in tendon reconstruction of the hand. Inspired by the advantages of the two-stage technique in tendon grafting and with encouraging preliminary results, we aimed to investigate the two-stage nerve grafting technique as an alternative method of secondary nerve repair. Methods: Thirty female rats (~200 g) were randomly distributed into two group...

  3. Approaches to Peripheral Nerve Repair: Generations of Biomaterial Conduits Yielding to Replacing Autologous Nerve Grafts in Craniomaxillofacial Surgery

    Science.gov (United States)

    Knipfer, Christian; Hadlock, Tessa

    2016-01-01

    Peripheral nerve injury is a common clinical entity, which may arise due to traumatic, tumorous, or even iatrogenic injury in craniomaxillofacial surgery. Despite advances in biomaterials and techniques over the past several decades, reconstruction of nerve gaps remains a challenge. Autografts are the gold standard for nerve reconstruction. Using autografts, there is donor site morbidity, subsequent sensory deficit, and potential for neuroma development and infection. Moreover, the need for a second surgical site and limited availability of donor nerves remain a challenge. Thus, increasing efforts have been directed to develop artificial nerve guidance conduits (ANCs) as new methods to replace autografts in the future. Various synthetic conduit materials have been tested in vitro and in vivo, and several first- and second-generation conduits are FDA approved and available for purchase, while third-generation conduits still remain in experimental stages. This paper reviews the current treatment options, summarizes the published literature, and assesses future prospects for the repair of peripheral nerve injury in craniomaxillofacial surgery with a particular focus on facial nerve regeneration. PMID:27556032

  4. Sensory nerve function and auto-mutilation after reconstruction of various gap lengths with nerve guides and autologous nerve grafts.

    Science.gov (United States)

    den Dunnen, W F; Meek, M F

    2001-05-01

    The aim of this study was to evaluate sensory nerve recovery and auto-mutilation after reconstruction of various lengths of nerve gaps in the sciatic nerve of the rat, using different techniques. Group 4, in which the longest nerve gap (15 mm) was reconstructed with a thin-walled p(DL-lactide-gamma-caprolactone) nerve guide filled with modified denatured muscle tissue, showed the best results in the electro-stimulation tests and signs of severe auto-mutilation were not observed. Even in the control group, in which a 10 mm nerve gap was left open, in two of the five rats improvement of the sensory nerve function was observed, which was caused by re-innervation of the sciatic nerve and not by expansion of the neighboring saphenous nerve. It is hypothesized that a better quality of nerve reconstruction/guidance channel/support results in faster regeneration and hence re-innervation, thereby, preventing auto-mutilation. A thin red glabrous skin, anhydrosis (dryness of the skin), short nails and edema were interpreted as signs of autonomic dysfunction. PMID:11352096

  5. Comparison of divided sciatic nerve growth within dermis, venous and nerve graft conduit in rat

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    Mohammad Javad Fatemi

    2010-01-01

    Conclusions: In the present study, dermis was used as the nerve conduit for the first time. This study indicates that the dermal tube is not a suitable conduit for nerve regeneration till further studies to resolve the problems before clinical application.

  6. Selectivity of distal reinnervation of regenerating mixed motor and sensory nerve fibres across muscle grafts in rats.

    Science.gov (United States)

    Rath, S; Green, C J

    1991-04-01

    This study investigated target specificity during axonal regeneration of a mixed motor and sensory nerve towards respective targets. The femoral nerves in rats were divided and allowed to grow across a 6 mm gap interposed with frozen and thawed muscle grafts towards their distal motor and sensory nerve stumps. Fourteen weeks later the number of motoneurons projecting axons into the motor and sensory branches were determined by retrograde axonal tracing using horse-radish peroxidase. There were significantly higher numbers of motoneurons (p = 0.0034) projecting into the motor nerve than the sensory nerve. Efferent axons of a mixed nerve selectivity grew into motor branches when allowed to regenerate across a 6 mm gap interposed with muscle grafts. It is possible that a deliberately created 'structured gap' during repair of mixed nerves could improve axonal matching by allowing expression of neurotropism. PMID:2025759

  7. Construction and biological testing of artificial implants for peripheral nerve repair

    OpenAIRE

    Kriebel, Andreas

    2016-01-01

    In this thesis I documented the development of an artificial nerve conduit and subsequent biological testing within an animal model of peripheral nerve injury. The focus for the development of the conduit lied in the utilization of electrospun microfibers to serve as a guidance structure for Schwann cells and axons during regeneration. Through the incorporation of such a guidance structure into the lumen of a conventional hollow nerve conduit, Schwann cell migration and axonal elongation acro...

  8. Electrical Nerve Stimulation Enhances Perilesional Branching after Nerve Grafting but Fails to Increase Regeneration Speed in a Murine Model.

    Science.gov (United States)

    Witzel, Christian; Brushart, Thomas M; Koulaxouzidis, Georgios; Infanger, Manfred

    2016-07-01

    Background Electrical stimulation immediately following nerve lesion helps regenerating axons cross the subsequently grafted nerve repair site. However, the results and the mechanisms remain open to debate. Some findings show that stimulation after crush injury increases axonal crossing of the repair site without affecting regeneration speed. Others show that stimulation after transection and fibrin glue repair doubles regeneration distance. Methods Using a sciatic-nerve-transection-graft in vivo model, we investigated the morphological behavior of regenerating axons around the repair site after unilateral nerve stimulation (20 Hz, 1 hour). With mice expressing axonal fluorescent proteins (thy1-YFP), we were able to calculate the following at 5 and 7 days: percentage of regenerating axons and arborizing axons, branches per axon, and regeneration distance and speed. Results Brief stimulation significantly increases the percentage of regenerating axons (5 days: 35.5 vs. 27.3% nonstimulated, p < 0.05; 7 days: 43.3 vs. 33.9% nonstimulated, p < 0.05), mainly by increasing arborizing axons (5 days: 49.3 [4.4] vs. 33.9 [4.1]% [p < 0.001]; 7 days: 42.2 [5.6] vs. 33.2 [3.1]% [p < 0.001]). Neither branches per arborizing axon nor regeneration speed were affected. Conclusion Our morphological data analysis revealed that electrical stimulation in this model increases axonal crossing of the repair site and promotes homogeneous perilesional branching, but does not affect regeneration speed. PMID:26975563

  9. A combination of Schwann-cell grafts and aerobic exercise enhances sciatic nerve regeneration.

    Directory of Open Access Journals (Sweden)

    Camila Oliveira Goulart

    Full Text Available Despite the regenerative potential of the peripheral nervous system, severe nerve lesions lead to loss of target-organ innervation, making complete functional recovery a challenge. Few studies have given attention to combining different approaches in order to accelerate the regenerative process.Test the effectiveness of combining Schwann-cells transplantation into a biodegradable conduit, with treadmill training as a therapeutic strategy to improve the outcome of repair after mouse nerve injury.Sciatic nerve transection was performed in adult C57BL/6 mice; the proximal and distal stumps of the nerve were sutured into the conduit. Four groups were analyzed: acellular grafts (DMEM group, Schwann cell grafts (3×105/2 µL; SC group, treadmill training (TMT group, and treadmill training and Schwann cell grafts (TMT + SC group. Locomotor function was assessed weekly by Sciatic Function Index and Global Mobility Test. Animals were anesthetized after eight weeks and dissected for morphological analysis.Combined therapies improved nerve regeneration, and increased the number of myelinated fibers and myelin area compared to the DMEM group. Motor recovery was accelerated in the TMT + SC group, which showed significantly better values in sciatic function index and in global mobility test than in the other groups. The TMT + SC group showed increased levels of trophic-factor expression compared to DMEM, contributing to the better functional outcome observed in the former group. The number of neurons in L4 segments was significantly higher in the SC and TMT + SC groups when compared to DMEM group. Counts of dorsal root ganglion sensory neurons revealed that TMT group had a significant increased number of neurons compared to DMEM group, while the SC and TMT + SC groups had a slight but not significant increase in the total number of motor neurons.These data provide evidence that this combination of therapeutic strategies can significantly improve functional

  10. Experimental study on regeneration of ascending tract after spinal cord injury with predegenerated peripheral nerve graft and NGF infusion

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective:To explore the effects of predegenerated peripheral nerve graft (PPNG) combined with nerve growth factor (NGF) infusion on ascending sensory tract regeneration after spinal cord injury.Methods: Fifty female SD rats were randomly divided into 5 groups. Group A was treated with PPNG and NGF infusion, group B with PPNG, group C with NGF infusion, group D and group E were blank and normal control, respectively. Horseradish peroxidase-labled (HRP) tracing method was employed to evaluate the regeneration of injured nerves after 8 weeks. The extent of regeneration in and beyond the nerve graft was determined by counting the number of HRP-labeled fibers intersecting imaginary lines perpendicular to the axis of the graft and cord. For the sake of convenience, according to the relation of the PNG and spinal cord, 6 model zones were divided, including caudal of spinal cord, caudal transition zone, caudal zone in graft, rostral zone in graft, rostral transition zone and rostral of spinal cord. Results: On the transverse section of caudal zone in graft, rostral zone in graft, rostral transition zone, the fibers in group A were significantly higher than that in group B and C (P<0.05). Conclusion: PPNG combined with NGF may significantly promote the regeneration of ascending long tract after spinal cord injury. The regenerative fibers can penetrate the 2 graft-host interface scars.

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

    International Nuclear Information System (INIS)

    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)

  12. Enhancement of Polyethylene Terephthalate Artificial Ligament Graft Osseointegration using a Periosteum Patch in a Goat Model.

    Science.gov (United States)

    Dai, Z; Bao, W; Li, S; Li, H; Jiang, J; Chen, S

    2016-06-01

    The purpose of this study is to investigate whether a periosteum patch could enhance polyethylene terephthalate (PET) artificial ligament graft osseointegration in a bone tunnel. 12 female goats underwent ACL reconstruction with a PET artificial ligament graft in the right knees. Right knees in 6 goats were reconstructed with periosteum patch-enveloped PET grafts (Periosteum group) in the tibia bone tunnel, whereas the other 6 goats had no periosteum patch and served as the Control group. All the goats were sacrificed at 12 months after surgery. 3 tibial-graft complex samples in each group were harvested consecutively for microcomputed tomography (micro-CT) scan, magnetic resonance imaging (MRI) scan and histological evaluation. The other 3 tibial-graft complex samples in each group were harvested for biomechanical testing. The mean pull-out load of the Periosteum group (208±25 N) at 12 months was significantly higher than that of the Control group (107±13 N) (p=0.0044). According to the micro-CT scan, more new bone formation was observed at the graft-bone interface in the Periosteum group compared with the Control group. Furthermore, MRI showed that the Periosteum group appeared to have a better graft osseointegration within the bone tunnel compared with the Control group. Histologically, application of a periosteum patch induced more new bone and Sharpey's fiber formation between the graft and bone tunnel compared with the controls. The study has shown that periosteum enveloping of the PET artificial ligament has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel. PMID:26990720

  13. Facial nerve anastomosis in the mastoid portion using a cable graft. Case report.

    Science.gov (United States)

    Kunert, Przemysław; Skawiński, Marcin; Marchel, Andrzej

    2011-01-01

    We describe a case of a 52-year-old woman in whom surgery for two tumours located in the cerebellar hemisphere and in the posterior petrous bone was complicated by interruption of the facial nerve (CN VII). During the same procedure, anastomosis of CN VII, using a cable graft harvested from the great auricular nerve, was performed. Seven months later the first signs of reinnervation of the facial muscles were noticed. Two and a half years after surgery, CN VII function was assessed as grade II/III according to the House-Brackmann scale. The authors emphasize the significance of immediate repair of CN VII in modern skull base surgery but also the importance of a patient's self-training to obtain the best functional outcome of the facial reanimation. Reconstruction using the great auricular nerve has two significant advantages: first, the patient avoids further procedures for nerve repair, and second, the harvested nerve is located in direct proximity to the operation area. PMID:22127947

  14. Artificial facial nerve reflex restores eyelid closure following orbicularis oculi muscle denervation

    Institute of Scientific and Technical Information of China (English)

    Yujuan Wang; Keyong Li; Jingquan Liu; Dongyue Xu; Yuefeng Rui; Chunsheng Yang

    2010-01-01

    To date, treatment of peripheral facial paralysis has focused on preservation of facial nerve integrity. However, with seriously damaged facial nerve cases, it is difficult to recover anatomical and functional integrity using present therapies. Therefore, the present study utilized artificial facial nerve reflex to obtain orbicularis oculi muscle (OOM) electromyography signals on the uninjured side through the use of implanted recording electrodes. The implanted electrical chips analyzed facial muscle motion on the uninjured side and triggered an electrical stimulator to emit current pulses, which resulted in stimulation of injured OOM contraction and maintained bilateral symmetry and consistency. Following signal recognition, extraction, and computer analysis, electromyography signals in the uninjured OOM resulted in complete eyelid closure, which was consistent with the voltage threshold for eye closure. These findings suggested that artificial facial nerve reflex through the use of implanted microelectronics in unilateral peripheral facial paralysis could restore eyelid closure following orbicularis oculi muscle denervation.

  15. Composite coating of 58S bioglass and hydroxyapatite on a poly (ethylene terepthalate) artificial ligament graft for the graft osseointegration in a bone tunnel

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the effect of the combination of hydroxyapatite (HA) and bioglass (BG) on polyethylene terephthalate (PET) artificial ligament graft osseointegration within the bone tunnel. The results of in vitro culturing of MC3T3-E1 mouse osteoblastic cells proved that this HA/BG composite coating can promote the cell compatibility of grafts. A rabbit extraarticular tendon-to-bone healing model was used to evaluate the effect of this composite coating on PET artificial ligaments in vivo. The final results demonstrated that HA/BG coating improved new bone formation at the graft-bone interface and increased the load-to-failure property of graft in bone tunnel compared to the control group at early time. The study has shown that HA/BG composite coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel.

  16. An inside-out vein graft filled with platelet-rich plasma for repair of a short sciatic nerve defect in rats

    OpenAIRE

    Kim, Ji Yeong; Jeon, Woo Joo; Kim, Dong Hwee; Rhyu, Im Joo; Kim, Young Hwan; Youn, Inchan; Park, Jong Woong

    2014-01-01

    Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats ...

  17. An inside-out vein graft iflled with platelet-rich plasma for repair of a short sciatic nerve defect in rats

    Institute of Scientific and Technical Information of China (English)

    Ji Yeong Kim; Woo Joo Jeon; Dong Hwee Kim; Im Joo Rhyu; Young Hwan Kim; Inchan Youn; Jong Woong Park

    2014-01-01

    Platelet-rich plasma containing various growth factors can promote nerve regeneration. An in-side-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft iflled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft iflled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft iflled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft iflled with platelet-rich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.

  18. Brain-derived neurotrophic factor expression in dorsal root ganglion neurons in response to reanastomosis of the distal stoma after nerve grafting

    Institute of Scientific and Technical Information of China (English)

    Wei Yu; Jian Wang; Mingzhu Xu; Hanjiao Qin; Shusen Cui

    2012-01-01

    Studies have shown that retreatment of the distal stoma after nerve grafting can stimulate nerve regeneration. The present study attempted to verify the effects of reanastomosis of the distal stoma, after nerve grafting, on nerve regeneration by assessing brain-derived neurotrophic factor expression in 2-month-old rats. Results showed that brain-derived neurotrophic factor expression in L2-4 dorsal root ganglia began to increase 3 days after autologous nerve grafting post sciatic nerve injury, peaked at 14 days, decreased at 28 days, and reached similar levels to the sham-surgery group at 56 days. Brain-derived neurotrophic factor expression in L2-4 dorsal root ganglia began to increase 3 days after reanastomosis of the distal stoma, 59 days after autologous nerve grafting post sciatic nerve injury, significantly increased at 63 days, peaked at 70 days, and gradually decreased thereafter, but remained higher compared with the sham-surgery group up to 112 days. The results of this study indicate that reanastomosis of the distal stoma after orthotopic nerve grafting stimulated brain-derived neurotrophic factor expression in L2-4 dorsal root ganglia.

  19. Immunohistochemical, ultrastructural and functional analysis of axonal regeneration through peripheral nerve grafts containing Schwann cells expressing BDNF, CNTF or NT3.

    Directory of Open Access Journals (Sweden)

    Maria João Godinho

    Full Text Available We used morphological, immunohistochemical and functional assessments to determine the impact of genetically-modified peripheral nerve (PN grafts on axonal regeneration after injury. Grafts were assembled from acellular nerve sheaths repopulated ex vivo with Schwann cells (SCs modified to express brain-derived neurotrophic factor (BDNF, a secretable form of ciliary neurotrophic factor (CNTF, or neurotrophin-3 (NT3. Grafts were used to repair unilateral 1 cm defects in rat peroneal nerves and 10 weeks later outcomes were compared to normal nerves and various controls: autografts, acellular grafts and grafts with unmodified SCs. The number of regenerated βIII-Tubulin positive axons was similar in all grafts with the exception of CNTF, which contained the fewest immunostained axons. There were significantly lower fiber counts in acellular, untransduced SC and NT3 groups using a PanNF antibody, suggesting a paucity of large caliber axons. In addition, NT3 grafts contained the greatest number of sensory fibres, identified with either IB4 or CGRP markers. Examination of semi- and ultra-thin sections revealed heterogeneous graft morphologies, particularly in BDNF and NT3 grafts in which the fascicular organization was pronounced. Unmyelinated axons were loosely organized in numerous Remak bundles in NT3 grafts, while the BDNF graft group displayed the lowest ratio of umyelinated to myelinated axons. Gait analysis revealed that stance width was increased in rats with CNTF and NT3 grafts, and step length involving the injured left hindlimb was significantly greater in NT3 grafted rats, suggesting enhanced sensory sensitivity in these animals. In summary, the selective expression of BDNF, CNTF or NT3 by genetically modified SCs had differential effects on PN graft morphology, the number and type of regenerating axons, myelination, and locomotor function.

  20. Utilization of artificial neural networks in the diagnosis of optic nerve diseases.

    Science.gov (United States)

    Kara, Sadik; Güven, Ayşegül; Oner, Ayşe Oztürk

    2006-04-01

    This research is concentrated on the diagnosis of optic nerve disease through the analysis of pattern electroretinography (PERG) signals with the help of artificial neural network (ANN). Multilayer feed forward ANN trained with a Levenberg Marquart (LM) backpropagation algorithm was implemented. The designed classification structure has about 96.4% sensitivity, 90.4% specifity and positive prediction is calculated to be 94.2%. The end results are classified as healthy and diseased. Testing results were found to be compliant with the expected results that are derived from the physician's direct diagnosis. The end benefit would be to assist the physician to make the final decision without hesitation. PMID:16488775

  1. A novel artiifcial nerve graft for repairing long-distance sciatic nerve defects:a self-assembling peptide nanoifber scaffold-containing poly(lactic-co-glycolic acid) conduit

    Institute of Scientific and Technical Information of China (English)

    Xianghai Wang; Jiasong Guo; Mengjie Pan; Jinkun Wen; Yinjuan Tang; Audra D Hamilton; Yuanyuan Li; Changhui Qian; Zhongying Liu; Wutian Wu

    2014-01-01

    In this study, we developed a novel artiifcial nerve graft termed self-assembling peptide nanoifber scaffold (SAPNS)-containing poly(lactic-co-glycolic acid) (PLGA) conduit (SPC) and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implanta-tion group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myoifber diameter in the target muscle. These ifndings suggest that the novel artiifcial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury.

  2. Polyethylene glycol acrylate-grafted polysulphone membrane for artificial lungs: plasma modification and haemocompatibility improvement.

    Science.gov (United States)

    Wang, Weiping; Huang, Xin; Yin, Haiyan; Fan, Wenling; Zhang, Tao; Li, Lei; Mao, Chun

    2015-12-01

    In this study, polyethylene glycol acrylate (PEGA) was introduced onto the surface of polysulphone (PSF) membrane to prepare PSF-PEGA membranes through low-temperature plasma technology for haemocompatibility improvement of artificial lungs. The effects of plasma power, PEGA solution concentration and dipcoating temperature on surface modification were systematically investigated. Results of Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and PEGA grafting degree confirmed that PEGA was successfully grafted onto the PSF membranes. Contact angle values showed that the hydrophilicity of the PSF-PEGA membrane surface increased by 21.5%. The results of the protein adsorption, platelet adhesion and coagulation tests further showed the excellent haemocompatibility of the modified membrane. Gas exchange tests also revealed that at a porcine blood flow rate of 5 l min(-1), O2 and CO2 exchange rates through the PSF-PEGA membrane were 198.6 and 170.9 ml min(-1), respectively; approximately this is the gas exchange capacity of commercial respiratory assistance devices. PMID:26658212

  3. Grafting

    International Nuclear Information System (INIS)

    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. (author)

  4. Chitosan-film enhanced chitosan nerve guides for long-distance regeneration of peripheral nerves.

    Science.gov (United States)

    Meyer, Cora; Stenberg, Lena; Gonzalez-Perez, Francisco; Wrobel, Sandra; Ronchi, Giulia; Udina, Esther; Suganuma, Seigo; Geuna, Stefano; Navarro, Xavier; Dahlin, Lars B; Grothe, Claudia; Haastert-Talini, Kirsten

    2016-01-01

    Biosynthetic nerve grafts are developed in order to complement or replace autologous nerve grafts for peripheral nerve reconstruction. Artificial nerve guides currently approved for clinical use are not widely applied in reconstructive surgery as they still have limitations especially when it comes to critical distance repair. Here we report a comprehensive analysis of fine-tuned chitosan nerve guides (CNGs) enhanced by introduction of a longitudinal chitosan film to reconstruct critical length 15 mm sciatic nerve defects in adult healthy Wistar or diabetic Goto-Kakizaki rats. Short and long term investigations demonstrated that the CNGs enhanced by the guiding structure of the introduced chitosan film significantly improved functional and morphological results of nerve regeneration in comparison to simple hollow CNGs. Importantly, this was detectable both in healthy and in diabetic rats (short term) and the regeneration outcome almost reached the outcome after autologous nerve grafting (long term). Hollow CNGs provide properties likely leading to a wider clinical acceptance than other artificial nerve guides and their performance can be increased by simple introduction of a chitosan film with the same advantageous properties. Therefore, the chitosan film enhanced CNGs represent a new generation medical device for peripheral nerve reconstruction. PMID:26517563

  5. Semi-skeletonized Internal Mammary Grafts and Phrenic Nerve Injury: Cause-and-effect analysis

    Institute of Scientific and Technical Information of China (English)

    DENG Yongzhi; SUN Zongquan; MA Jie; Hugh S PATERSON

    2006-01-01

    Phrenic nerve injury after cardiac surgery increases postoperative pulmonary complications. The purpose of this study was to analyze the causes and effects of phrenic nerve injury after cardiac surgery. Prospectively collected data on 2084 consecutive patients who underwent cardiac surgery from Jan. 1995 to Feb. 2002 were analyzed. Twenty-eight preoperative and operation related variables were subjected to logistic analysis with the end point being phrenic nerve injury. Then phrenic nerve injury and 6 perioperative morbidities were included in the analysis as variables to determine their independent predictive value for perioperative pulmonary morbidity. An identical approach was used to identify the independent risk factors for perioperative mortality. There were 53 phrenic nerve injuries (2.5 %). There was no phrenic nerve injury in non-coronary surgery or coronary surgery using conduits other than the internal mammary artery. The independent risk factors for phrenic nerve injury were the use of internal mammary artery (Odds ratio (OR)=14.5) and the presence of chronic obstructive pulmonary disease (OR=2.9). Phrenic nerve injury was an independent risk factor (OR=8.1) for perioperative pulmonary morbidities but not for perioperative mortality. Use of semi-skeletonized internal mammary artery harvesting technique and drawing attention to possible vascular or mechanical causes of phrenic nerve injury may reduce its occurrence. Unilateral phrenic nerve injury, although rarely life-threatening, is an independent risk factor for postoperative respiratory complications. When harvesting internal mammary arteries, it should be kept in mind avoiding stretching, compromising, or inadvertently dissecting phrenic nerve is as important as avoiding damage of internal mammary artery itself.

  6. Effects of liquid nitrogen cryotherapy and bone grafting on artificial bone defects in minipigs: a preliminary study.

    Science.gov (United States)

    Pogrel, M A; Regezi, J A; Fong, B; Hakim-Faal, Z; Rohrer, M; Tran, C; Schiff, T

    2002-06-01

    Liquid nitrogen cryotherapy has been advocated as an adjunct in the enucleation and curettage of locally aggressive lesions of the jaws. Simultaneous autogenous bone grafting has also been advocated to accelerate bone formation and reduce morbidity. There is, however, relatively little scientific basis for either of these hypotheses. In this study, nine Yucatan minipigs had artificial defects created in the mandible, which were treated with liquid nitrogen spray. Half of the defects were grafted with autogenous bone from the chin and half were closed primarily. Two animals were sacrificed 3 days postoperatively to measure the width of necrosis and the rest were sacrificed at 3 months to assess healing and new bone formation. It was found that drilling the artificial defects alone caused bone necrosis for a mean depth of 0.09 mm. Liquid nitrogen cryospray caused a mean depth of bone necrosis of 0.82 mm (range 0.51-1.52 mm). The defects that were bone grafted healed well clinically. Defects not bone grafted showed a 50% rate of wound breakdown and sequestrum formation with delayed healing. Vital staining showed a non-significantly greater rate of bone formation in the grafted defects. Digitally superimposed radiography showed a non-significantly greater bone density in the non-grafted defects at 3 months postoperatively. It appears that liquid nitrogen cryospray does devitalize an area of bone around defects in the mandible. The width of necrosis is usually less than 1 mm and subsequent healing is enhanced by autogenous bone grafting. This has clinical implications. PMID:12190137

  7. FUNCTIONAL CONNECTIONS ARE ESTABLISHED BETWEEN GIANT NERVE FIBERS IN GRAFTED EARTHWORMS

    Science.gov (United States)

    Giant fiber interconnections were examined in successful grafts between two posterior portions of earthworms (Eisenia foetida). Electrophysiological and histological results indicated that cell-specific interanimal connections were formed between the medial giant fibers (MGF) in ...

  8. 神经组织工程支架或异种神经移植在面神经缺损中的应用%Nerve tissue engineering scaffolds or heterologous nerve grafts in facial nerve defects

    Institute of Scientific and Technical Information of China (English)

    宁丽娜; 熊杰

    2011-01-01

    背景:了解面神经损伤的修复方法,以及各种组织支架的特性与优势,对于修复方法与材料的合理选择是十分必要的.目的:总结神经组织工程支架或异种神经移植在面神经缺损中的应用进展.方法:应用计算机检索PubMed数据库及CNKI数据库,在标题和摘要中以"组织工程支架,神经移植,面神经,修复"或"tissue engineering scaffolds,nerve transplantation,facial,repair"为检索词进行检索.根据纳入标准选择21篇文献进行综述.结果与结论:面神经缺损后立即直接缝合神经的断端是最好的修复方法.自体神经移植受神经移植体来源之限,常造成供区失神经支配;以及产生束外有髓和无髓轴突无规则生长会导致神经纤维错向再生,造成严重的联带运动的不足.异体或异种神经移植法虽然取得了一定的效果,但仍处于动物实验的研究阶段,尚难以应用于临床.%BACKGROUND: It is necessary for proper selection of repair methods and scaffold materials to understand repair methods of facial nerve injury and features and benefits of various scaffolds.OBJECTIVE: To summarize the progress in nerve tissue engineering scaffolds or heterologous nerve grafts for repair of facial nerve defects.METHODS: A computer search of PubMed and CNKI databases were performed using keyword of “tissue engineering scaffold, nerve transplantation, facial, repair” in Chinese and English. Totally 21 articles were reviewed.RESULTS AND CONCLUSION: It is the best method to directly suture nerve stump immediately after facial nerve defects. Autologous nerve grafting is limited by implant sources, which often result in denervation of the donor site. Irregular growth of extrapyramidal myelinated and non-myelinated axons can lead to the fault regeneration of nerve fibers, causing serious shortcomings associated with the movement. Allogeneic or xenogeneic neural transplantation has yielded some results, but it is still used in

  9. [Flowmetric assessment of coronary bypass grafts in the conditions of artificial circulation and on the beating heart].

    Science.gov (United States)

    Bazylev, V V; Nemchenko, E V; Karnakhin, V A; Pavlov, A A; Mikulyak, A I

    2016-01-01

    Advantages and shortcomings of aortocoronary bypass grafting on the beating heart and in the conditions of artificial circulation (AC) have long been discussed. The data on patency of bypass grafts in the remote period are indicative of comparable results of operations with and without AC or advantages of using AC. In order to determine benefits of each method it is necessary to reveal intraoperative predictors of bypass grafts occlusion in the remote period. We analyzed the results of ultrasound flowmetry of the blood flow through the left internal thoracic artery during bypass grafting of the anterior descending artery with the use of AC and on the beating heart. A retrospective study included a total of 352 patients subdivided into 2 groups: Group One was composed of 120 patients undergoing surgery in the conditions of AC and Group Two comprised 232 patients subjected to similar operations on the beating heart. Blood flow was measured with the help of flowmeter VeryQ MediStim® after termination of AC and inactivation of heparin by protamine, with systolic pressure of 100-110 mm Hg. There were no statistically significant differences between the groups by the diameter and degree of stenosis of the anterior descending artery, diameter of the left internal thoracic artery. The mean volumetric blood flow velocity (Qmean) along the shunts in Group One was higher (p=0.01). No statistically significant differences by the pulsatility index (PI) between the groups were revealed (p=0.2). A conclusion was drawn that coronary bypass grafting of the anterior descending artery by the left internal thoracic artery in the conditions of artificial circulation made it possible to achieve higher volumetric velocity of blood flow through the conduit as compared with operations on the beating heart, with similar resistance index. The immediate results of the operations with the use of the both techniques did not differ. PMID:27100540

  10. Application of artificial neural network to predict graft survival after kidney transplantation: Reports of 22 years follow up of 316 patients in Isfahan

    Directory of Open Access Journals (Sweden)

    Ashrafi M

    2009-08-01

    Full Text Available "nBackground: Kidney transplantation had been evaluated in some researches in Iran mainly with clinical approach. In this research we evaluated graft survival in kidney recipients and factors impacting on survival rate. Artificial neural networks have a good ability in modeling complex relationships, so we used this ability to demonstrate a model for prediction of 5yr graft survival after kidney transplantation."n"n"n Methods: This retrospective study was done on 316 kidney transplants from 1984 through 2006 in Isfahan. Graft survival was calculated by Kaplan-meire method. Cox regression and artificial neural networks were used for constructing a model for prediction of graft survival."n"n"n Results: Body mass index (BMI and type of transplantation (living/cadaver had significant effects on graft survival in cox regression model. Effective variables in neural network model were recipient age, recipient BMI, type of transplantation and donor age. One year, 3 year and 5 year graft survival was 96%, 93% and 90% respectively. Suggested artificial neural network model had good accuracy (72% with the area under the Receiver-Operating Characteristic (ROC curve 0.736 and appropriate results in goodness of fit test (κ2=33.924. Sensitivity of model in identification of true positive situations was more than false negative situations (72% Vs 61%."n"n"nConclusion: Graft survival in living donors was more than cadaver donors. Graft survival decreased when the BMI increased at transplantation time. In traditional statistical approach Cox regression analysis is used in survival analysis, this research shows that artificial neural networks also can be used in constructing models to predict graft survival in kidney transplantation.  

  11. The Impact of Motor and Sensory Nerve Architecture on Nerve Regeneration

    OpenAIRE

    MORADZADEH, ARASH; Borschel, Gregory H.; Luciano, Janina P.; Whitlock, Elizabeth L.; Hayashi, Ayato; Hunter, Daniel A.; Mackinnon, Susan E.

    2008-01-01

    Sensory nerve autografting is the standard of care for injuries resulting in a nerve gap. Recent work demonstrates superior regeneration with motor nerve grafts. Improved regeneration with motor grafting may be a result of the nerve’s Schwann cell basal lamina tube size. Motor nerves have larger SC basal lamina tubes, which may allow more nerve fibers to cross a nerve graft repair. Architecture may partially explain the suboptimal clinical results seen with sensory nerve grafting techniques. ...

  12. Effect of swirling flow on platelet concentration distribution in small-caliber artificial grafts and end-to-end anastomoses

    Science.gov (United States)

    Zhan, Fan; Fan, Yu-Bo; Deng, Xiao-Yan

    2011-10-01

    Platelet concentration near the blood vessel wall is one of the major factors in the adhesion of platelets to the wall. In our previous studies, it was found that swirling flows could suppress platelet adhesion in small-caliber artificial grafts and end-to-end anastomoses. In order to better understand the beneficial effect of the swirling flow, we numerically analyzed the near-wall concentration distribution of platelets in a straight tube and a sudden tubular expansion tube under both swirling flow and normal flow conditions. The numerical models were created based on our previous experimental studies. The simulation results revealed that when compared with the normal flow, the swirling flow could significantly reduce the near-wall concentration of platelets in both the straight tube and the expansion tube. The present numerical study therefore indicates that the reduction in platelet adhesion under swirling flow conditions in small-caliber arterial grafts, or in end-to-end anastomoses as observed in our previous experimental study, was possibly through a mechanism of platelet transport, in which the swirling flow reduced the near-wall concentration of platelets.

  13. 同种异体神经修复鼠坐骨神经缺损的实验研究%An experimental study on allogenic nerve grafts repairing the gap of rat sciatic nerve

    Institute of Scientific and Technical Information of China (English)

    刘世清; 张思胜; 彭昊; 陶海鹰; 范里

    2004-01-01

    AIM:To study the effect of nerve regeneration through bridging the gap of rat sciatic nerve with acellular basal laminea tubes. METHODS:Acellular basal lamina tubes were acquired from normal rat sciatic nerves which were treated with nondenaturing biological detergents.Thirty adult SD rats were divided randomly into three groups, with 10 in each group. Acellular basal lamina tubes graft group A);autogenous nerve bridging(group B); allogenic nerve bridging(group C). A gap of 20 mm of rat left sciatic nerve was extracted, which was bridged by different nerve materials.Histomorphometry, electromyographic and image analysis were determined at 2 and 3 months after surgical operation. RESULTS:A number of axons in regenerating nerve were found to cross the graft, the latency and wave amplitude of regenerating nerve in group A were lower than that in group B(ta=2.101,P< 0.05;tb=5.00, P< 0.05)at 2 months, there was no statistical difference betwen the two groups at 3 months.The thickness of myelin sheath of experimental group was inferior to group B(ta=5.68,P< 0.05)at 3 months, while the number and diameter of axons in both groups were similar. CONCLUSION: The graft is found to support outgrowth of axons and migration of Schwann cell,and is a good tool to use in peripheral nerve regeneration.%目的:研究无细胞基膜管桥接鼠坐骨神经缺损后的神经再生效果.方法 :正常鼠坐骨神经用非变性生物剂处理后得到无细胞的基膜管,桥接鼠坐骨神经 20 mm缺损.实验分 3组:无细胞基膜管移植组(A组);自体神经移植组(B组);异体神经移植组(C组).术后进行肌电图、组织形态学及图像分析仪检查.结果 : A组再生神经有大量轴突通过移植体,术后 2个月电生理检测再生神经的潜伏期及波幅低于 B组(ta=2.101, P< 0.05; tb=5.00, P< 0.05), 3个月时无显著性差异.髓鞘厚度在术后 3个月时亦低于 B组,有显著性差异(ta=5.68, P< 0.05).轴突直径及

  14. Magnetic resonance imaging study of lumbosacral spinal cord nerves before artificial somatic-central nervous system-autonomic reflex pathway establish ment

    International Nuclear Information System (INIS)

    Objective: To investigate the value of MRI as imaging technique for lumbosacral spinal nerves before artificial somatic-central nervous system-autonomic reflex pathway establish ment. Methods: Conventional MRI and T2W CISS 3D were performed in 10 patients with neurogenic bladder planned for the operation of artificial somatic-central nervous system-autonomic reflex pathway. The Three-dimensional data were then constructed into composite images using a standard multiple planar reformation (MPR). Results: Five patients showed tethered spinal cord syndrome, whose spinal cord nerves were circuitous distributed and had abnormity number when penetrated the dura. Of these 5 patients, one patient was accompanied by spinal cord vas malformation. Four patients had vertebral fracture and spinal injury, and the other one patients demonstrated tumor in vertebral canal on MRI examinations. The spinal cord nerves in these 5 patients floated down river and had normal number of spinal cord nerves. Conclusion: Conventional MRI and T2W CISS 3D MRI were essential for the pre-operative planning of artificial somatic-central nervous system-autonomic reflex pathway, especially in patients with tethered spinal cord syndrome. Spinal cord nerves distribute and anterior and posterior roots array can be clearly showed by MPR. (authors)

  15. Using Stem Cells to Grow Artificial Tissue for Peripheral Nerve Repair

    Science.gov (United States)

    Bhangra, Kulraj Singh; Busuttil, Francesca

    2016-01-01

    Peripheral nerve injury continues to pose a clinical hurdle despite its frequency and advances in treatment. Unlike the central nervous system, neurons of the peripheral nervous system have a greater ability to regenerate. However, due to a number of confounding factors, this is often both incomplete and inadequate. The lack of supportive Schwann cells or their inability to maintain a regenerative phenotype is a major factor. Advances in nervous system tissue engineering technology have led to efforts to build Schwann cell scaffolds to overcome this and enhance the regenerative capacity of neurons following injury. Stem cells that can differentiate along a neural lineage represent an essential resource and starting material for this process. In this review, we discuss the different stem cell types that are showing promise for nervous system tissue engineering in the context of peripheral nerve injury. We also discuss some of the biological, practical, ethical, and commercial considerations in using these different stem cells for future clinical application.

  16. Adipose derived stem cells and nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Alessandro Faroni; Richard JP Smith; Adam J Reid

    2014-01-01

    Injuries to peripheral nerves are common and cause life-changing problems for patients along-side high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacriifcing a section of nerve from elsewhere in the body to pro-vide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacriifce of a functional nerve. Stem cells are prime candidates as accelerators of re-generation in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts.

  17. Potential of nanocrystalline cellulose-fibrin nanocomposites for artificial vascular graft applications

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Elvie; Hu, Dehong; Abu-Lail, Nehal; Zhang, Xiao

    2013-02-19

    Nanocrystalline cellulose, a new bio-nanomaterial is utilized as a reinforcing material for biocompatible fibrin matrix to form into a nanocomposite for small-diameter replacement vascular graft application (SDRVG). The periodate oxidation of NCC, which provided it with a reactive carbonyl group, allowed molecular interaction between NCC and fibrin. Such interaction resulted into an effective mechanical reinforcement indicated by the improvement of max. force, elongation at break and modulus when oxidized NCC (ONCC) was incorporated into fibrin. The nanocomposite’s mechanical properties can be manipulated to conform to the native blood vessel by varying the ONCC to fibrin ratio and/or by controlling the degree of oxidation of NCC. Using atomic force microscopy had provided fundamental information on the effects of molecular interactions to the nanolevel mechanical properties of NCC/fibrin nanocomposites. This fundamental information established the positive feasibility and commenced continuing investigation for the practical SDRVG application of NCC/fibrin nanocomposite.

  18. Electrospun polycaprolactone/polylactic acid nanofibers as an artificial nerve conduit

    International Nuclear Information System (INIS)

    Development of conduits made of biodegradable nanofibers is gaining substantial interest due to their suitability for nerve regeneration. Among all polymeric nanofibers PCL (Poly-Caprolactone) is distinctively found for mechanical stability and PLLA (Poly (L-Lactic Acid)) for relatively faster biodegradability. The aim of this study is to investigate blending compatibility between PCL and PLLA and the ability to fabricate nanofibers conduits via electro spinning. The PCL-PLLA nano-fiber tubular made from different blend ratios of PCL-PLLA were electro spun. The electro spun nanofibers were continuously deposited over high speed rotating mandrel to fabricate nanofibers conduit having inner diameter of 2mm and the wall thickness of 55-65 m. The diameters of nano-fibers were between 715-860nm. FTIR (Fourier Transform Infrared) spectroscopy used to analyze chemical change in the blends of nerve conduits, which revealed that the PCL-PLLA blend nanofiber exhibit characteristic peaks of both PCL and PLLA and was composition dependent. The crystallinity of PCL-PLLA tubes were studied using WAXD (Wide Angle Xray Diffraction). The morphology of nanofibers were investigated under SEM (Scanning Electron Microscope). The mechanical properties of the conduits were also tested; the Young's modulus obtained for small diameter was 10MPa, twice as high as larger diameter. (author)

  19. Electrospun Polycaprolactone/Polylactic Acid Nanofibers as an Artificial Nerve Conduit

    Directory of Open Access Journals (Sweden)

    Zeeshan Ali Khatri

    2014-07-01

    Full Text Available Development of conduits made of biodegradable nanofibers is gaining substantial interest due to their suitability for nerve regeneration. Among all polymeric nanofibers PCL (Poly ?-Caprolactone is distinctively found for mechanical stability and PLLA (Poly (L-Lactic Acid for relatively faster biodegradability. The aim of this study is to investigate blending compatibility between PCL and PLLA and the ability to fabricate nanofibers conduits via electro spinning. The PCL-PLLA nano-fiber tubular made from different blend ratios of PCL-PLLA were electro spun. The electro spun nanofibers were continuously deposited over high speed rotating mandrel to fabricate nanofibers conduit having inner diameter of 2mm and the wall thickness of 55-65µm. The diameters of nano-fibers were between 715-860nm. FTIR (Fourier Transform Infrared spectroscopy used to analyze chemical change in the blends of nerve conduits, which revealed that the PCL-PLLA blend nanofiber exhibit characteristic peaks of both PCL and PLLA and was composition dependent. The crystallinity of PCL-PLLA tubes were studied using WAXD (Wide Angle Xray Diffraction. The morphology of nanofibers were investigated under SEM (Scanning Electron Microscope. The mechanical properties of the conduits were also tested; the Young?s modulus obtained for small diameter was 10MPa, twice as high as larger diameter.

  20. A comparative study of calcium sulfate artificial bone graft versus allograft in the reconstruction of bone defect after tumor curettage

    Institute of Scientific and Technical Information of China (English)

    Yang Yongkun; Niu Xiaohui; Zhang Qing; Hao Lin; Ding Yi; Xu Hairong

    2014-01-01

    Background Cavity reconstruction after benign bone tumor removal is varied and controversial.AIIograft is widely used but is associated with complications.New bone substitutes,such as calcium sulfate artificial bone,have been introduced for bone tumor operation.However,the bone healing response of artificial bone has not been compared with allograft bone.We therefore compared calcium sulfate grafts (study group) with bone allografts (control group) for the treatment of benign bone tumors.Methods We retrospectively reviewed 50 patients who underwent calcium sulfate reconstruction and 50 patients who underwent allograft cancellous bone reconstruction.The two groups were well matched.The mean follow-up time of the study group was 19.9 (12-55) months.We investigated bone healing response,complications,and factors affecting bone healing.Results At the last follow-up,84% (42/50) of cases in the study group and 62% (31/50) of cases in the control group had achieved clinical healing (P=0.013).The initial healing rate showed no significant difference between the two groups (100% vs.96%,P=0.153).The mean healing times for calcium sulfate and allograft bone were 9.6 (3-42) months and 13.8 (3-36) months,respectively (P <0.01).Complications in the study group were minor and resolved.Implant volume was a significant factor affecting bone healing.Conclusion The calcium sulfate bone substitute showed a satisfactory healing outcome and safety profile in reconstruction of bone defects after benign bone tumor curettage,especially in smaller cavities.

  1. Interventional recanalization of artificial arteriovenous fistula and graft for hemodialysis: angioplasty and pulsed-spray thrombolysis with Urokinase

    International Nuclear Information System (INIS)

    To evaluate the effectiveness of percutaneous transluminal angioplasty (PTA) and pul-sed-spray pharmaco-mechanical thrombolysis (PSPMT) using urokinase for the management of insufficient hemodialysis access. Between September 1996 and May 1998, 21 insufficient hemodialysis accesses were treated in 16 patients(3 artificial arteriovenous fistulae, AVF; and 13 arteriovenous graft, AVG). PTA and PSPMT were performed in 6 and 15 cases, respectively, and success and long-term patency rates were evaluated. The overall success rate of PTA and PSPMT for insufficient hemodialysis access was 76. 2%(16/21). The success rates of PTA and PSPMT were 83.3%(5/6) and 73.3%(11/15), respectively. The primary patency rates of PSPMT were 69±12.8% at 6 months and 38±18.6% at 12 months. One of the two initially successful PTAs had been patent for 7 months, and the second PTA was performed at that time due to venous stenosis. The other was patent for 15 months throughout the follow-up period. PTA and PSPMT are effective primary methods for the treatment of insufficient hemodialysis access;success and patency rates were high, and the procedures can be performed repeatedly.=20

  2. Facial Nerve Neuroma Management

    OpenAIRE

    Weber, Peter C; Osguthorpe, J. David

    1998-01-01

    Three facial nerve neuromas were identified in the academic year 1994-1995. Each case illustrates different management dilemmas. One patient with a grade III facial nerve palsy had a small geniculate ganglion neuroma with the dilemma of decompression versus resection clear nerve section margins. The second patient underwent facial neuroma resection with cable graft reconstruction, but the permanent sections were positive. The last patient had a massive neuroma in which grafting versus other f...

  3. Sciatic nerve regeneration in rats by a promising electrospun collagen/poly(ε-caprolactone nerve conduit with tailored degradation rate

    Directory of Open Access Journals (Sweden)

    Jiang Xinquan

    2011-07-01

    Full Text Available Abstract Background To cope with the limitations faced by autograft acquisitions particularly for multiple nerve injuries, artificial nerve conduit has been introduced by researchers as a substitute for autologous nerve graft for the easy specification and availability for mass production. In order to best mimic the structures and components of autologous nerve, great efforts have been made to improve the designation of nerve conduits either from materials or fabrication techniques. Electrospinning is an easy and versatile technique that has recently been used to fabricate fibrous tissue-engineered scaffolds which have great similarity to the extracellular matrix on fiber structure. Results In this study we fabricated a collagen/poly(ε-caprolactone (collagen/PCL fibrous scaffold by electrospinning and explored its application as nerve guide substrate or conduit in vitro and in vivo. Material characterizations showed this electrospun composite material which was made of submicron fibers possessed good hydrophilicity and flexibility. In vitro study indicated electrospun collagen/PCL fibrous meshes promoted Schwann cell adhesion, elongation and proliferation. In vivo test showed electrospun collagen/PCL porous nerve conduits successfully supported nerve regeneration through an 8 mm sciatic nerve gap in adult rats, achieving similar electrophysiological and muscle reinnervation results as autografts. Although regenerated nerve fibers were still in a pre-mature stage 4 months postoperatively, the implanted collagen/PCL nerve conduits facilitated more axons regenerating through the conduit lumen and gradually degraded which well matched the nerve regeneration rate. Conclusions All the results demonstrated this collagen/PCL nerve conduit with tailored degradation rate fabricated by electrospinning could be an efficient alternative to autograft for peripheral nerve regeneration research. Due to its advantage of high surface area for cell attachment, it

  4. Axonal regeneration through arterial grafts.

    OpenAIRE

    Anderson, P. N.; Turmaine, M.

    1986-01-01

    The left common peroneal nerves of adult inbred mice were severed and allowed to regenerate through the lumina of Y-shaped tubes comprising grafts of abdominal aorta and its bifurcation. Very little regeneration took place within the grafts unless the distal nerve stump was inserted into one limb of the Y-tube. Using syngeneic grafts virtually all the axons regenerating through the lumen grew down the limb of the Y-tube containing the distal nerve. Using non-syngeneic grafts, however, a subst...

  5. High Ulnar Nerve Injuries: Nerve Transfers to Restore Function.

    Science.gov (United States)

    Patterson, Jennifer Megan M

    2016-05-01

    Peripheral nerve injuries are challenging problems. Nerve transfers are one of many options available to surgeons caring for these patients, although they do not replace tendon transfers, nerve graft, or primary repair in all patients. Distal nerve transfers for the treatment of high ulnar nerve injuries allow for a shorter reinnervation period and improved ulnar intrinsic recovery, which are critical to function of the hand. PMID:27094893

  6. Obstetrical brachial plexus palsy: Can excision of upper trunk neuroma and nerve grafting improve function in babies with adequate elbow flexion at nine months of age?

    Science.gov (United States)

    Argenta, Anne E; Brooker, Jack; MacIssac, Zoe; Natali, Megan; Greene, Stephanie; Stanger, Meg; Grunwaldt, Lorelei

    2016-05-01

    Accepted indications for exploration in obstetrical brachial plexus palsy (OBPP) vary by center. Most agree that full elbow flexion against gravity at nine months of age implies high chance of spontaneous recovery and thus excludes a baby from surgical intervention. However, there are certain movements of the shoulder and forearm that may not be used frequently by the infant, but are extremely important functionally as they grow. These movements are difficult to assess in a baby and may lead to some clinicians to recommend conservative treatment, when this cohort of infants may in fact benefit substantially from surgery. A retrospective review was conducted on all infants managed surgically at the Brachial Plexus Center of a major children's hospital from 2009 to 2014. Further analysis identified five patients who had near-normal AMS scores for elbow flexion but who had weakness of shoulder abduction, flexion, external rotation, and/or forearm supination. In contrast to standard conservative management, this cohort underwent exploration, C5-6 neuroma excision, and sural nerve grafting. Data analysis was performed on this group to look for overall improvement in function. During an average follow-up period of 29 months, all patients made substantial gains in motor function of the shoulder and forearm, without loss of elbow flexion or extension, or worsening of overall outcome. In select infants with brachial plexus injuries but near-normal AMS scores for elbow flexion, surgical intervention may be indicated to achieve the best functional outcome. PMID:26806089

  7. Effects of Co-grafts Mesenchymal Stem Cells and Nerve Growth Factor Suspension in the Repair of Spinal Cord Injury

    Institute of Scientific and Technical Information of China (English)

    FANG Huang; WANG Junfang; CHEN Anmin

    2006-01-01

    To investigate effect of the transplantation of mesenchymal stem cells (MSCs) in combination with nerve growth factor (NGF) on the repair of spinal cord injury (SCI) in adult rats, spinal cord of adult rats (n= 32) was injured by using the modified Allen' s method. One week after the injury, the injured cords were injected with Dubecco-modified Eagles medium (DMEM , Group Ⅰ), MSCs (Group Ⅱ), NGF (Group Ⅲ), and MSCs plus NGF (Group Ⅳ). One month and two months after the injury, rats were sacrificed and their injured cord tissues were sectioned for the identification of the transplanted cells. The axonal regeneration and the differentiation of MSCs were examined by immunocytochemical staining. At the same time, rats were subjected to behavioral tests by using the open-field BBB scoring system. Immunocytochemical staining showed that axonal regeneration and the transplanted cells partially expressed neuron-specific nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP). At the same time, significant improvement in BBB locomotor rating scale (P<0.05) were observed in the treatment group. More importantly, further functional improvement were noted in the combined treatment group. MSCs could differentiate into neurons and astrocytes. MSCs and NGF can promote axonal regeneration and improve functional recovery. There might exist a synergistic effect between MSCs and NGF.

  8. Experiment on graft of bone marrow-derived neural stem cells in peripheral nerve%骨髓源性神经干细胞周围神经移植的实验

    Institute of Scientific and Technical Information of China (English)

    李贵涛; 徐如祥; 姜晓丹; 杨志军; 代广辉; 陈镇洲; 黄涛

    2005-01-01

    on neural stem cells (NSCs) is almost focused on neuronal cells, for which, the study on repair of peripheral nerve may be based on some experiences in NSCs.OBJECTIVE: To observe the repair of peripheral nerve after graft of autologus bone marrow derived NSCs in the injured area. To observe whether the grafted NSCs were survived and migrated in spinal cord as differentiated neurons in the injured area of peripheral nerve or not.DESIGN: Observed controlled experiment was designed.SETTING: Institute of Neurological Medicine of Zhujiang Hospital affiliated to Southern Medical UniversityMATERIALS: Eight New Zealand big white rabbits were employed, of clean grade, mass weighted varied from 1.5 to 2.5 kg and of either sex.METHODS: The experiment was performed in Institute of Neurological Medicine of Zhujiang Hospital affiliated to Southern Medical University collected from New Zealand big white rabbits for culture and differentiation was prepared. Sciatic neural injured area of one side was randomized as graft side. Physiological saline, collagen matrix and cellular embedding solution were infused up to 0.01 mL (containing stem cells 1×1010L-1). Another side was taken as the control, in which, collagen matrix suspension 0.01 mL was infused. Peffusion and fixation were followed 3 months after graft and auto-graft was performed in the injured peripheral nerve. The materials were collected for observation from graft area, spinal cord area, injured area on the opposite side and normal neural area.MAIN OUTCOME MEASURES: Morphology of nerve fibers and neuronal cells in NSC graft area, spinal cord area and non-graft area on opposite injury side.RESULTS: The density and continuity of nerve fibers grown in graft area were higher remarkably than non-graft area on opposite side and more Schwann cells were seen under optic microscope. With amplified ×400 visual field, Ranvier's node of spinal nerve fiber was visible. In addition,mucous matrix and few fibroblasts were seen also in

  9. 去细胞异种神经复合神经生长因子修复神经缺损的实验研究%Repair of peripheral nerve gap with xenogeneic acellular graft combined with nerve growth factor

    Institute of Scientific and Technical Information of China (English)

    郝增涛; 温树正; 马玉霞; 王继宏

    2010-01-01

    nerve gaps were repaired by acellular basal lamina tubes combined with nerve growth factor (NGF).Methods Fifteen adult Wistar rats were divided randomly into 3 even groups. A 1.0 cm long gap was created in the continuity of the sciatic nerve in each rat. The rabbit tibial nerve was excised to make xenogeneic acellular nerve basal lamina tubes, the ultrastructure of which was observed by electron microscopy and HE coloration. The MHC Ⅱ antigen contents were examined by flow cytometry before and after the rabbit tibial nerves were treated with chemical detergents. In group A, xenogeneic acellular basal lamina tubes were grafted with NGF; in group B, only xenogeneic acellular basal lamina tubes were grafted; in group C, autogenous nerves were grafted. The nerve functional restoration was observed by electrophysiological experiments in all rats one month postoperatively in terms of motor evoked potential of the musculus triceps surae and the motor conduction velocity at the grafted sciatic nerve segments. Morphological and morphometric analyses were done by optical microscopy, electron microscopy and immunohistochemical techniques. Results The nerve regeneration, nerve fiber arrangement and nerve function reconstruction in group A were better than in group B, and similar to those in group C. Conclusions The rabbit tibial nerve treated with chemical detergents can be grafted to repair the nerve gap in rats. As the acellular basal lamina tubes combined with NGF can better improve nerve regeneration by enhancing the growth of regenerating axons and migration of Schwann cells than those without NGF, they may be a good substitute for nerve grafts.

  10. 同种异体神经复合体修复兔坐骨神经缺损的研究%Planting fetus rabbit schwann cells into the extracted acellular nerve graft of homogeneity in repairing rabbit sciatic nerve defect

    Institute of Scientific and Technical Information of China (English)

    杨小华; 韩金豹; 张沉冰; 田德虎; 韩久卉

    2009-01-01

    Objective To plant fetus rabbit Schwann cells that were cultured and purified in vitro into the chemically extracted acellular nerve graft of homogeneity and made it into bridging complex. Then transplant the bridging complex into the rabbit defective sciatic nerve. The experiment was designed to investigate the effect of the nerve allografts on the functional recovery and the condition of nerve regeneration. Methods 48 adult healthy New-Zealand albino rabbits,weighing 1.5-2.0 kg,were randomly divided into 2 groups with 24 rabbits each group,based on different grafts. The bridging complex were composed of Schwann cell, then transplanted it to repair defective sciatic nerve of the experiment group rabbit. The control group did not transplant Schwann cells. The sciatic nerve of lower left limb was cut in order to emerge 2cm nerves defect for each rabbit,then was transplated with different grafts. Observed the ulcers on the feet of the rabbit 4,8 and 16 weeks after operation. To observe sciatic nerve regeneration and myelination by light microscope. To observe the information of nerve regeneration and myelination and the ultrastructural change of the mitochondrion, the microtubule, the microfilament and Schwann cells by electron microscope. Make use of the analytical system on picture to treat the number of regenerated nerve fiber and the axon diameter and the thickness of myelin sheath of medullated nerve fibers,then measured the wet weight of the triceps surae. Then analyzed them in statistics. Results After operation, the immunological rejection was not found in the operating field. The experimental group was better than the control group in healing of ulcers, after 4,8,16 weeks,the number of regenerated nerve fiber and the axon diameter and the thickness of myelin sheath of medullated nervefibers (906.25 ± 30.68,1726.25 ±51. 89,2825.13 ± 22.79) , (5.35 ± 0.62,5.46 ±0.38,5.59 ±0.80), (1.65 ±0.37,1.75 ±0.41,1.83 ±0.49) (P 0.05). But after 8 and 16 weeks

  11. Comparison of long - term outcome of nerve regeneration between two methods of lengthy vascularized ulnar nerve grafting: an experimental study%比较两种带血供长段尺神经移植术神经再生远期结果的实验研究

    Institute of Scientific and Technical Information of China (English)

    徐杰; 顾玉东; 成效敏; 董震; 劳杰; 陈亮

    2001-01-01

    Objective To compare the long - term experimental results in nerve regeneration between two methods of lengthy vascularized ulnar nerve grafting. Methods Nine New Zealand rabbits were used. The ulnar nerves of bilateral sides were dissected and cut at the wrist and at the point where the superior ulnar collateral artery (SUCA) originated from the brachial artery, and repaired in situ. The ulnar nerve was vascularized by SUCA onn the right side, and by SUCA and the ulnar artery (UA) on the left side. Seven months later, electromyography of the ulnar nerve was recorded. The number of regenerated myelinated nerve fibers and its cross - sectional area, the thickness of the myelin sheath (mt), the ratio (d/D) of axonal diameter (d) to total fiber diameter (D), and muscle histology were analyzed. Results The front foot ulcer of the 9 rabbits healed 7 months after the operation. Nerve action potential amplitude and motor nerve conduction velocity of the ulnar nerve of the right side were inferior to those of the left side. As for the number and cross - sectional area of regenerated myelinated nerve fibers, no difference was found at the level 3 cm proximal to the suture site at the wrist between the two sides. When compared at the level 1cm proximal to and 0.5 cm distal to the suture site at the wrist, the ones of the left side were superior to those of the right side. There was no difference considering the wet muscle weight and muscle fiber cross - sectional area of the hypothenar muscles, myelin sheath thickness and d/D ratio at two sides. Conclusions Both methods of lengthy vascularized ulnar nerve grafting can obtain satisfactory results. Difference of regenerated nerve fiber count between the two procedures was found at the distal part of nerve graft. Therefore it is recommended to elongate dissection length of the graft above elbow and to shorten the graft below elbow in the clinical applications of ulnar nerve grafting with SUCA.%目的对带尺侧上副

  12. The anatomical research of grafting ring finger radial digital branch of median nerve for repairing injuried deep branch of ulnar nerve defects%正中神经环指桡侧指神经支移植修复尺神经深支缺损的应用解剖

    Institute of Scientific and Technical Information of China (English)

    王斌; 尹佳丽; 董秀芝; 陈超; 韩海生; 李浩

    2011-01-01

    目的 为研究环指桡侧指神经支移植修复尺神经深支缺损提供解剖学基础. 方法 对16例32侧新鲜成人上肢进行观测.在10倍手术显微镜下对腕部尺神经深支、正中神经旋前方肌支和环指桡侧指神经支进行显微解剖及测量. 结果 正中神经旋前方肌支直径为(1.13±0.02)mm,正中神经环指桡侧指神经支直径为(1.17±0.05)mm,对掌肌管出口处尺神经深支直径为(1.75±0.07)mm.显微镜下分离环指桡侧指神经支,对掌肌管出口处尺神经深支至旋前方肌支入肌长度即移植段神经长度为(104.59±20.25)mm. 结论 环指桡侧指神经支移植为带血运的神经移植,属肌支对肌支的吻合,是修复尺神经深支缺损的有效方法.%Objective To provide anatomical basis of neural transplantation to repair deep branch of ulnar nerve defect with the ring finger radial digital branch. Methods Thirty-two sides of 16 cases fresh forearms were dissected and observed.Microdissect and measure the deep branch of ulnar nerve,quadrate pronator of median nerve and it's ring finger radial digital branch under 10-times operating microscope. Results The diameter of quadrate pronator of median nerve was (1.13 ± 0.02)mm,ring finger radial digital branch of median nerve was (1.17 ± 0.05)mm,mid-palmar section of deep branch of ulnar nerve was(1.75± 0.07)mm.Dissect ring finger radial digital branch of median nerve to muscular branch of quadrate pronator under operating microscope,retaining it's blood supply.The length between the deep branch of ulnar nerve and ring finger radial digital branch was( 104.59 ± 20.25)mm.Conclusion ①Solving the problem of nerve grafting without blood supply before,benefit to the survival of the grafting segment and the regeneration of the neuro fiber,and function restoring.②This kind of grafting is the bridging of muscular branch to muscular branch,abide by the principle of neurophysiology.③Neural transplantation to repair deep

  13. Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2015-01-01

    Full Text Available Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ′excellent′ and ′good′ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.

  14. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis

    OpenAIRE

    Yu, Tao; ZHAO, CHANGFU; Li, Peng; Liu, Guangyao; Luo, Min

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transpl...

  15. The Use of Degradable Nerve Conduits for Human Nerve Repair: A Review of the Literature

    Directory of Open Access Journals (Sweden)

    M. F. Meek

    2005-01-01

    Full Text Available The management of peripheral nerve injury continues to be a major clinical challenge. The most widely used technique for bridging defects in peripheral nerves is the use of autologous nerve grafts. This technique, however, has some disadvantages. Many alternative experimental techniques have thus been developed, such as degradable nerve conduits. Degradable nerve guides have been extensively studied in animal experimental studies. However, the repair of human nerves by degradable nerve conduits has been limited to only a few clinical studies. In this paper, an overview of the available international published literature on degradable nerve conduits for bridging human peripheral nerve defects is presented for literature available until 2004. Also, the philosophy on the use of nerve guides and nerve grafts is given.

  16. Skin graft

    Science.gov (United States)

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

  17. Cartilage oligomeric matrix protein enhances the vascularization of acellular nerves

    Directory of Open Access Journals (Sweden)

    Wei-ling Cui

    2016-01-01

    Full Text Available Vascularization of acellular nerves has been shown to contribute to nerve bridging. In this study, we used a 10-mm sciatic nerve defect model in rats to determine whether cartilage oligomeric matrix protein enhances the vascularization of injured acellular nerves. The rat nerve defects were treated with acellular nerve grafting (control group alone or acellular nerve grafting combined with intraperitoneal injection of cartilage oligomeric matrix protein (experimental group. As shown through two-dimensional imaging, the vessels began to invade into the acellular nerve graft from both anastomotic ends at day 7 post-operation, and gradually covered the entire graft at day 21. The vascular density, vascular area, and the velocity of revascularization in the experimental group were all higher than those in the control group. These results indicate that cartilage oligomeric matrix protein enhances the vascularization of acellular nerves.

  18. In vivo study of novel nanofibrous intra-luminal guidance channels to promote nerve regeneration

    Science.gov (United States)

    Koh, H. S.; Yong, T.; Teo, W. E.; Chan, C. K.; Puhaindran, M. E.; Tan, T. C.; Lim, A.; Lim, B. H.; Ramakrishna, S.

    2010-08-01

    A novel nanofibrous construct for promoting peripheral nerve repair was fabricated and tested in a rat sciatic nerve defect model. The conduit is made out of bilayered nanofibrous membranes with the nanofibers longitudinally aligned in the lumen and randomly oriented on the outer surface. The intra-luminal guidance channel is made out of aligned nanofibrous yarns. In addition, biomolecules such as laminin and nerve growth factor were incorporated in the nanofibrous nerve construct to determine their efficacy in in vivo nerve regeneration. Muscle reinnervation, withdrawal reflex latency, histological, axon density and electrophysiology tests were carried out to compare the efficacy of nanofibrous constructs with an autograft. Our study showed mixed results when comparing the artificial constructs with an autograft. In some cases, the nanofibrous conduit with aligned nanofibrous yarn as an intra-luminal guidance channel performs better than the autograft in muscle reinnervation and withdrawal reflex latency tests. However, the axon density count is highest in the autograft at mid-graft. Functional recovery was improved with the use of the nerve construct which suggested that this nerve implant has the potential for clinical usage in reconstructing peripheral nerve defects.

  19. Nerve Transfers for Adult Traumatic Brachial Plexus Palsy (Brachial Plexus Nerve Transfer)

    OpenAIRE

    Rohde, Rachel S.; Wolfe, Scott W.

    2006-01-01

    Adult traumatic brachial plexus injuries can have devastating effects on upper extremity function. Although neurolysis, nerve repair, and nerve grafting have been used to treat injuries to the plexus, nerve transfer makes use of an undamaged nerve to supply motor input over a relatively short distance to reinnervate a denervated muscle. A review of several recent innovations in nerve transfer surgery for brachial plexus injuries is illustrated with surgical cases performed at this institution.

  20. 周围神经修复临床疗效的科学评价%Scientific assessment on the outcome of clinical application with peripheral nerve graft materials

    Institute of Scientific and Technical Information of China (English)

    何波; 刘小林; 朱庆棠; 郑灿镔; 顾立强; 朱家恺

    2011-01-01

    Objective To discuss how to assess scientifically on the outcome of clinical application with peripheral nerve graft materials. Methods All Pubmed database from 1990 to 2010 were retrieved,and searched the English literatures about the application with peripheral nerve graft materials. The literatures consisted of original clinical research and review excluding animal experiments, repetitive research and irrelevant literatures. The clinical trials data of U.S. was also our target. The information about the safety and effectiveness of peripheral nerve graft materials and related statistical problems were discussed. Results Totally 1578 literatures were identified. Following reading titles and abstracts, we excluded some irrelevant articles. Finally 31 literatures and 2 issue of clinical research from clinical trial data of U.S. were included. After analysis on the literatures, we gained the following results: a remarkable degree of homogeneity among patients can be formed by setting the inclusion and exclusion criteria. For the assessment of proper digital nerve repair, Macknnon- Dellon evaluation is commonly applied, but for the composite nerve, BMRC evaluation is the main method and electromyography can be used as a secondary choice. The safety of peripheral nerve graft materials cannot be evaluated throughout one's life according to the current level of science and technology. It should be evaluated by long-term clinical observation. Randomized clinical trials with random grouping was a gold standard for clinical trials with a good balance and strong comparability. However, non-randomized controlled trials also have an important value. Conclusion It is impossible to make all affected factors homogeneity in a limited timespace conditions of clinical trial. However, we can try our best to keep factors homogeneity to maximum degree by setting the inclusion and exclusion criteria. The scientific assessment of outcome of peripheral nerve repair can be carried out with

  1. The overwhelming use of rat models in nerve regeneration research may compromise designs of nerve guidance conduits for humans

    OpenAIRE

    Hilton M. Kaplan; Mishra, Prakhar; Kohn, Joachim

    2015-01-01

    Rats are not the best model for the evolving complexities we face in designing nerve repair strategies today. The development of effective nerve guidance conduits for nerve regeneration is severely limited by the rat sciatic nerve model as the almost exclusive research model in academia. An immense effort is underway to develop an alternative to autologous nerve grafts for the repair of nerve defects, aiming particularly at larger gap repairs of 5–30 cm or more. This must involve combinations...

  2. Development of a scaffoldless three-dimensional engineered nerve using a nerve-fibroblast co-culture

    OpenAIRE

    Baltich, Jennifer; Hatch-Vallier, Leah; Adams, Aaron M.; Arruda, Ellen M; Larkin, Lisa M.

    2009-01-01

    Nerve grafts are often required to replace tissue damaged by disease, surgery, or extensive trauma. Limitations such as graft availability, donor site morbidity, and immune rejection have led investigators to develop strategies to engineer nerve tissue. The goal of this study was to fabricate a scaffoldless three-dimensional (3D) nerve construct using a co-culture of fetal nerve cells with a fibroblast monolayer and allow the co-culture to remodel into a 3D construct with an external fibrobla...

  3. Bone Grafts

    Science.gov (United States)

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

  4. A comparative study of acellular nerve xenografts and allografts in repairing rat facial nerve defects.

    Science.gov (United States)

    Huang, Haitao; Xiao, Hongxi; Liu, Huawei; Niu, Yu; Yan, Rongzeng; Hu, Min

    2015-10-01

    Acellular nerves are composed of a basal lamina tube, which retains sufficient bioactivity to promote axon regeneration, thereby repairing peripheral nerve gaps. However, the clinical application of acellular allografts has been restricted due to its limited availability. To investigate whether xenografts, a substitute to allograft acellular nerves in abundant supply, could efficiently promote nerve regeneration, rabbit and rat acellular nerve grafts were used to reconstruct 1 cm defects in Wistar rat facial nerves. Autologous peroneal nerve grafts served as a positive control group. A total of 12 weeks following the surgical procedure, the axon number, myelinated axon number, myelin sheath thickness, and nerve conduction velocity of the rabbit and rat‑derived acellular nerve grafts were similar, whereas the fiber diameter of the rabbit‑derived acellular xenografts decreased, as compared with those of rat‑derived acellular allografts. Autografts exerted superior effects on nerve regeneration; however, no significant difference was observed between the axon number in the autograft group, as compared with the two acellular groups. These results suggested that autografts perform better than acellular nerve grafts, and chemically extracted acellular allografts and xenografts have similar effects on the regeneration of short facial nerve defects. PMID:26239906

  5. Augmentation of partially regenerated nerves by end-to-side side-to-side grafting neurotization: experience based on eight late obstetric brachial plexus cases

    Directory of Open Access Journals (Sweden)

    Moharram Ashraf N

    2006-12-01

    Full Text Available Abstract Objective The effect of end-to-side neurotization of partially regenerated recipient nerves on improving motor power in late obstetric brachial plexus lesions, so-called nerve augmentation, was investigated. Methods Eight cases aged 3 – 7 years were operated upon and followed up for 4 years (C5,6 rupture C7,8T1 avulsion: 5; C5,6,7,8 rupture T1 avulsion:1; C5,6,8T1 rupture C7 avulsion:1; C5,6,7 ruptureC8 T1 compression: one 3 year presentation after former neurotization at 3 months. Grade 1–3 muscles were neurotized. Grade0 muscles were neurotized, if the electromyogram showed scattered motor unit action potentials on voluntary contraction without interference pattern. Donor nerves included: the phrenic, accessory, descending and ascending loops of the ansa cervicalis, 3rd and 4th intercostals and contralateral C7. Results Superior proximal to distal regeneration was observed firstly. Differential regeneration of muscles supplied by the same nerve was observed secondly (superior supraspinatus to infraspinatus regeneration. Differential regeneration of antagonistic muscles was observed thirdly (superior biceps to triceps and pronator teres to supinator recovery. Differential regeneration of fibres within the same muscle was observed fourthly (superior anterior and middle to posterior deltoid regeneration. Differential regeneration of muscles having different preoperative motor powers was noted fifthly; improvement to Grade 3 or more occurred more in Grade2 than in Grade0 or Grade1 muscles. Improvements of cocontractions and of shoulder, forearm and wrist deformities were noted sixthly. The shoulder, elbow and hand scores improved in 4 cases. Limitations The sample size is small. Controls are necessary to rule out any natural improvement of the lesion. There is intra- and interobserver variability in testing muscle power and cocontractions. Conclusion Nerve augmentation improves cocontractions and muscle power in the biceps, pectoral

  6. Effects of subcutaneous implant of peripheral nerve allograft on the regeneration of defected sciatic nerve

    Institute of Scientific and Technical Information of China (English)

    Mingtang Gao; Dianming Jiang; Hong An

    2006-01-01

    BACKGROUND: Some experimental studies demonstrate that subcutaneous implant of allograft can significantly decrease lymphocyte infiltration and reduce immunological reaction. However, compared with autologous nerve grafting, what is the effect of nerve regeneration after repair?OBJECTIVE: To observe the local nervous status of the detected part of sciatic nerve repaired through subcutaneously implanting peripheral nerve allograft, and compare the effect with fresh autologous nerve grafting.DESIGN: Contrast observation.SETTING: Departments of Orthopaedics of Zhengzhou Fifth People's Hospital and First Hospital Affiliated to Chongqing Medical University.MATERIALS: Totally 30 healthy adult Wistar male rats, with body mass of (200±20)g, were enrolled. Optical microscope (Olympus biological microscope BHS, Japan), Electron microscope (H-600, Japan),CM-2000 biomedical image analysis system (CM-2000,Beihang) and myoelectricity scanner (KEYPOINT,Denmark) were used in this experiment.METHODS: This experiment was carried out in the Orthopaedic Laboratory of Chongqing Medical University between October 2000 and April 2002. ① Six rats were chosen as the donors for allogenic nerve grafting,and 15 mm sciatic nerve segment was chosen as graft. The other rats were randomly divided into two groups: allogenic nerve grafting group and autologous nerve grafting group, with 12 rats in each group. In the allogenic nerve grafting group, a skin incision was made on the posterior side of right thigh, and subcutaneous blunt dissection was performed prorsally a little, then allograft was implanted. Two weeks later, sciatic nerve was exposed at the posterior side of left thigh and cut respectively at 5 mm and another 10 mm away from pelvis. The donor nerve (with connective tissue veil) implanted subcutaneously on the right thigh was taken out. Sectioned connective tissue at the proximal end was trimmed and that at the distal end as done but reserved 10 mm in length, and inosculated

  7. Pinched Nerve

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS NINDS Pinched Nerve Information Page Table of Contents (click to jump ... being done? Clinical Trials Organizations What is Pinched Nerve? The term "pinched nerve" is a colloquial term ...

  8. Nerve biopsy

    Science.gov (United States)

    Biopsy - nerve ... A nerve biopsy is most often done on a nerve in the ankle, forearm, or along a rib. The health care ... feel a prick and a mild sting. The biopsy site may be sore for a few days ...

  9. Delayed peripheral nerve repair: methods, including surgical ′cross-bridging′ to promote nerve regeneration

    Directory of Open Access Journals (Sweden)

    Tessa Gordon

    2015-01-01

    Full Text Available Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour period of 20 Hz electrical nerve stimulation via electrodes proximal to an injury site accelerates axon outgrowth to hasten target reinnervation in rats and humans, even after delayed surgery. A novel strategy of enticing donor axons from an otherwise intact nerve to grow through small nerve grafts (cross-bridges into a denervated nerve stump, promotes improved axon regeneration after delayed nerve repair. The efficacy of this technique has been demonstrated in a rat model and is now in clinical use in patients undergoing cross-face nerve grafting for facial paralysis. In conclusion, brief electrical stimulation, combined with the surgical technique of promoting the regeneration of some donor axons to ′protect′ chronically denervated Schwann cells, improves nerve regeneration and, in turn, functional outcomes in the management of peripheral nerve injuries.

  10. 人工骨或自体骨移植联合椎弓根钉内固定修复脊柱结核%Artificial bone or autologous bone grafting combined with pedicle screw fixation for repair of spinal tuberculosis

    Institute of Scientific and Technical Information of China (English)

    姜棚菲; 翟文斌

    2015-01-01

    BACKGROUND:With the development of fixation materials and technology, scholars began to use artificial bone materials combined with pedicle screw fixation in the repair of spinal tuberculosis. OBJECTIVE: To summarize the characteristics of artificial bone materials combined with pedicle screw fixation in the repair of spinal tuberculosis. METHODS:The literatures about artificial bone graft materials in repair of spinal tuberculosis were retrieved from CNKI and PubMed database during 1985 to 2014 by computer. The keywords were “spinal tuberculosis, bone transplantation, internal fixation” in Chinese and English, respectively. RESULTS AND CONCLUSION:In the repair of spinal tuberculosis using artificial bone materials combined with pedicle screw fixation, autologous bone is the gold standard for bone grafting, presenting with no immune rejection. To avoid the occurrence of limited bone mass, pain and other complications, however, artificial bone materials have been extensively studied. Currently used artificial materials mainly include titanium and its aloys, hydroxyapatite composites and medical calcium sulfate, which al have good biocompatibility. But there are stil certain limitations and shortcomings.%背景:随着内固定材料和内固定技术的发展,越来越多的国内外学者开始应用人工骨材料联合椎弓根钉内固定修复脊柱结核。目的:综述人工骨修复材料联合椎弓根内固定修复脊柱结核的特点。方法:应用计算机检索CNKI和PubMed数据库1985至2014年有关人工骨移植材料修复脊椎结核方面的文献,中文关键词为“脊椎结核、骨移植、内固定”,英文关键词为“Spinal tuberculosis,Bone graft,Fixation”。结果与结论:在骨修复材料联合椎弓根内固定修复脊柱结核中,自体骨是骨移植的金标准,无免疫排斥反应,但为了避免自体骨取骨量有限、取骨后疼痛等并发症的发生,人工骨材料得到了广泛

  11. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve A mechanical analysis*

    Institute of Scientific and Technical Information of China (English)

    Tao Yu; Changfu Zhao; Peng Li; Guangyao Liu; Min Luo

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study col ected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, fol owing which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) con-duit-repaired sciatic nerve fol owing tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Fol owing poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogen-ous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair.

  12. Three-layer microfibrous peripheral nerve guide conduit composed of elastin-laminin mimetic artificial protein and poly(L-lactic acid)

    Science.gov (United States)

    Kakinoki, Sachiro; Nakayama, Midori; Moritan, Toshiyuki; Yamaoka, Tetsuji

    2014-07-01

    We developed a microfibrous poly(L-lactic acid) (PLLA) nerve conduit with a three-layered structure to simultaneously enhance nerve regeneration and prevent adhesion of surrounding tissue. The inner layer was composed of PLLA microfiber containing 25% elastin-laminin mimetic protein (AG73-(VPGIG)30) that promotes neurite outgrowth. The thickest middle layer was constructed of pure PLLA microfibers that impart the large mechanical stremgth to the conduit. A 10% poly(ethylene glycol) was added to the outer layer to prevent the adhesion with the surrounding tissue. The AG73-(VPGIG)30 composisting of an elastin-like repetitive sequence (VPGIG)30 and a laminin-derived sequence (RKRLQVQLSIRT: AG73) was biosynthesized using Escherichia coli. The PLLA microfibrous conduits were fabricated using an electrospinning procedure. AG73-(VPGIG)30 was successfully mixed in the PLLA microfibers, and the PLLA/AG73-(VPGIG)30 microfibers were stable under physiological conditions. The PLLA/AG73-(VPGIG)30 microfibers enhanced adhesion and neurite outgrowth of PC12 cells. The electrospun microfibrous conduit with a three-layered structure was implanted for bridging a 2.0-cm gap in the tibial nerve of a rabbit. Two months after implantation, no adhesion of surrounding tissue was observed, and the action potential was slightly improved in the nerve conduit with the PLLA/AG73-(VPGIG)30 inner layer.

  13. Three-layer microfibrous peripheral nerve guide conduit composed of elastin-laminin mimetic artificial protein and poly(L-lactic acid

    Directory of Open Access Journals (Sweden)

    Sachiro eKakinoki

    2014-07-01

    Full Text Available We developed a microfibrous poly(L-lactic acid (PLLA nerve conduit with a three-layered structure to simultaneously enhance nerve regeneration and prevent adhesion of surrounding tissue. The inner layer was composed of PLLA microfiber containing 25% elastin-laminin mimetic protein (AG73-(VPGIG30 that promotes neurite outgrowth. The thickest middle layer was constructed of pure PLLA microfibers that impart the large mechanical stremgth to the conduit. A 10% poly(ethylene glycol was added to the outer layer to prevent the adhesion with the surrounding tissue. The AG73-(VPGIG30 composisting of an elastin-like repetitive sequence (VPGIG30 and a laminin-derived sequence (RKRLQVQLSIRT: AG73 was biosynthesized using Escherichia coli. The PLLA microfibrous conduits were fabricated using an electrospinning procedure. AG73-(VPGIG30 was successfully mixed in the PLLA microfibers, and the PLLA/AG73-(VPGIG30 microfibers were stable under physiological conditions. The PLLA/AG73-(VPGIG30 microfibers enhanced adhesion and neurite outgrowth of PC12 cells. The electrospun microfibrous conduit with a three-layered structure was implanted for bridging a 2.0-cm gap in the tibial nerve of a rabbit. Two months after implantation, no adhesion of surrounding tissue was observed, and the action potential was slightly improved in the nerve conduit with the PLLA/AG73-(VPGIG30 inner layer.

  14. Substitution of natural sensory input by artificial neurostimulation of an amputated trigeminal nerve does not prevent the degeneration of basal forebrain cholinergic circuits projecting to the somatosensory cortex

    Directory of Open Access Journals (Sweden)

    Fivos Panetsos

    2014-11-01

    Full Text Available Peripheral deafferentation downregulates acetylcholine (ACh synthesis in sensory cortices. However the responsible neural circuits and processes are not known. We irreversibly transected the rat infraorbital nerve and implanted neuroprosthetic microdevices for proximal stump stimulation, and assessed cytochrome-oxidase and choline- acetyl-transferase (ChAT in somatosensory, auditory and visual cortices; estimated the number and density of ACh-neurons in the magnocellular basal nucleus (MBN; and localized down-regulated ACh-neurons in basal forebrain using retrograde labeling from deafferented cortices. Here we show that nerve transection, causes down regulation of MBN cholinergic neurons. Stimulation of the cut nerve reverses the metabolic decline but does not affect the decrease in cholinergic fibers in cortex or cholinergic neurons in basal forebrain. Artifical stimulation of the nerve also has no affect of ACh-innervation of other cortices. Cortical ChAT depletion is due to loss of corticopetal MBN ChAT-expressing neurons. MBN ChAT downregulation is not due to decrease neither of afferent activity nor to failure of trophic support. Basalocortical ACh circuits are sensory specific, ACh is provided to each sensory cortex "on demand" by dedicated circuits. Our data support the existence of a modality-specific cortex-MBN-cortex circuit for cognitive information processing.

  15. Neuroma sintomático do nervo sural uma complicação rara após a retirada do nervo: relato de caso Symptomatic neuroma of the sural nerve a rare complication of the harvesting of the nerve for grafting: case report

    Directory of Open Access Journals (Sweden)

    Roberto S. Martins

    2002-09-01

    Full Text Available A retirada do nervo sural para utilização como enxerto autólogo em cirurgias de nervos em geral produz sintomas de repercussão clínica pouco intensa e de duração fugaz. Raramente este procedimento leva a formação de neuroma sintomático no coto proximal. Os sintomas deste tipo de complicação frequentemente cessam após o tratamento clínico e o tratamento cirúrgico é reservado para os raros casos nos quais houve falha terapêutica. Neste estudo, apresentamos o caso de um paciente que foi submetido a tratamento cirúrgico desta patologia, com a utilização de uma variação da anastomose centro-central, descrita para o tratamento de neuromas de cotos de amputação. A utilização deste tratamento resultou na remissão da sintomatologia dolorosa. São discutidas as diversas opções de tratamento cirúrgico para essa rara entidade.The harvesting of the sural nerve for autologous grafting usually produces symptoms of low intensity and short duration. In rare occasions that procedure may lead to the formation of a symptomatic neuroma in the proximal stump. The symptons of this complication are usually controlled by clinical treatment and the surgical procedure is left for the therapeutic failures. In this paper we present the case of a patient with a sural nerve neuroma submitted to surgical treatment by a variant of the centro-central anastomosis technique, developed for the treatment of amputation neuromas, that resulted in remission of the painful symptomatology. The different options of surgical treatment for this rare entity are discussed.

  16. Combining acellular nerve allografts with brain-derived neurotrophic factor transfected bone marrow mesenchymal stem cells restores sciatic nerve injury better than either intervention alone

    OpenAIRE

    Zhang, Yanru; Zhang, Hui; Zhang, Gechen; Ka, Ka; Huang, Wenhua

    2014-01-01

    In this study, we chemically extracted acellular nerve allografts from bilateral sciatic nerves, and repaired 10-mm sciatic nerve defects in rats using these grafts and brain-derived neurotrophic factor transfected bone marrow mesenchymal stem cells. Experiments were performed in three groups: the acellular nerve allograft bridging group, acellular nerve allograft + bone marrow mesenchymal stem cells group, and the acellular nerve allograft + brain-derived neurotrophic factor transfected bone...

  17. Vascular endothelial growth factor promotes peripheral nerve regeneration after sciatic nerve transection in rat

    OpenAIRE

    Mohammadi Rahim; Ahsan Sima; Masoumi Masoume; Amini Keyvan

    2013-01-01

    【Abstract】Objective: To evaluate the local effect of vascular endothelial growth factor (VEGF) on transected sciatic nerve regeneration. Methods: Sixty male white Wistar rats were divided into four experimental groups randomly (n=15). In transected group the left sciatic nerve was transected and the stump was fixed to adjacent muscle. In treatment group the defect was bridged using a silicone graft filled with 10 µL VEGF. In silicone group the graft was filled with pho...

  18. Utilização da veia glicerolada na regeneração neural: Estudo experimental em ratos The use of glycerol-treated venous graft in damaged nerves repair: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Armando dos Santos Cunha

    2007-01-01

    Full Text Available A auto-enxertia de nervo é o tratamento de escolha para grandes perdas de tecido neural que não podem ser reparadas por meio de rafia primária. A utilização do enxerto venoso previamente conservado em glicerol seria uma alternativa para diminuir o tempo operatório e a morbidade cirúrgica nesses casos. Os vasos preservados em glicerol não apresentam destruição de sua estrutura, o que permite seu uso na microcirurgia vascular, tendo a vantagem de diminuir a imunogenicidade do enxerto. O objetivo deste trabalho experimental foi comparar o grau de reparação nervosa, utilizando análise histológica, contagem do número de axônios mielinizados regenerados e análise funcional, obtida com a interposição de enxerto autógeno (grupo A e de tubo de veia glicerolada (grupo B em defeitos de 5 mm no nervo fibular de ratos Wistar. Somente no grupo A foi observado a formação de neuroma. O grupo B apresentou padrões histológicos compatíveis com diminuição quantitativa do número de axônios mielinizados regenerados em menor número em relação ao grupo A (controle. Na recuperação funcional, não houve diferença estatisticamente significativa entre os dois grupos.Autografting is the treatment of choice for cases of major nervous tissue loss where the ruptured nerve ends cannot be reduced. The use of a venous autograft previously treated with glycerol may be an alternative treatment, as it reduces surgery time duration and level of morbidity. Blood vessel explants, used in vascular microsurgery, kept in glycerol maintain their original biological structure, and when used in autografting, present reduced levels of patient's immune response. The aim of this study was to compare the level of nervous tissue regeneration by using histological analysis, regenerated myelinized axons counts, and functional analysis, obtained with the interposition of autologous graft (group A and glycerol-treated vein tube (group B in 5-mm defects on Wistar

  19. Tubulization with chitosan guides for the repair of long gap peripheral nerve injury in the rat.

    OpenAIRE

    Gonzalez Perez, M; Cobianchi, Stefano; GEUNA, Stefano; Barwig, Christina; Freier, Thomas; Udina i Bonet, Esther; Navarro, X.

    2015-01-01

    Biosynthetic guides can be an alternative to nerve grafts for reconstructing severely injured peripheral nerves. The aim of this study was to evaluate the regenerative capability of chitosan tubes to bridge critical nerve gaps (15 mm long) in the rat sciatic nerve compared with silicone (SIL) tubes and nerve autografts (AGs). A total of 28 Wistar Hannover rats were randomly distributed into four groups (n = 7 each), in which the nerve was repaired by SIL tube, chitosan guides of low (∼2%, DAI...

  20. Biologically engineered protein-graft-poly(ethylene glycol) hydrogels: A cell-adhesive and plasmin-degradable biosynthetic material for tissue repair

    Science.gov (United States)

    Halstenberg, Sven

    2002-01-01

    The goal of the research presented in this dissertation was to create a biomimetic artificial material that exhibits functions of extracellular matrix relevant for improved nerve regeneration. Neural adhesion peptides were photoimmobilized on highly crosslinked poly(ethylene glycol)-based substrates that were otherwise non-adhesive. Neurons adhered in two-dimensional patterns for eleven hours, but no neurites extended. To enable neurite extension and nerve regeneration in three dimensions, and to address the need for specifically cell adhesive and cell degradable materials for clinical applications in tissue repair in general, an artificial protein was recombinantly expressed and purified that consisted of a repeating amino acid sequence based on fibrinogen and anti-thrombin III. The recombinant protein contained integrin-binding RGD sites, plasmin degradation sites, heparin binding sites, and six thiol-containing cysteine residues as grafting sites for poly(ethylene glycol) diacrylate via Michael-type conjugate addition. The resulting protein-graft-poly(ethylene glycol)acrylates were crosslinked by photopolymerization to form hydrogels. Although three-dimensional, RGD mediated and serine protease-dependent ingrowth of human fibroblasts into protein-graft-poly(ethylene glycol) hydrogels occurred, only surface neurite outgrowth was observed from chick dorsal root ganglia. Axonal outgrowth depended on the concentration of matrix-bound heparin, suggesting that improved mechanical strength of the hydrogels and possible immobilization of neuroactive factors due to the presence of heparin promoted neurite outgrowth. Together, the above results show that specific biological functions can be harnessed by protein-graft-poly(ethylene glycol) hydrogels to serve as matrices for tissue repair and regeneration. In particular, the two design objectives, specific cell adhesion and degradability by cell-associated proteases, were fulfilled by the material. In the future, this and

  1. Polymeric Nerve Conduits with Contact Guidance Cues Used in Nerve Repair

    Institute of Scientific and Technical Information of China (English)

    G DAI; X NIU; J YIN

    2016-01-01

    In the modern life, the nerve injury frequently happens due to mechanical, chemical or thermal accidents. In the trivial injuries, the peripheral nerves can regenerate on their own; however, in most of the cases the clinical treatments are required, where relatively large nerve injury gaps are formed. Currently, the nerve repair can be accomplished by direct suture when the injury gap is not too large;while the autologous nerve graft working as the gold standard of peripheral nerve injury treatment for nerve injuries with larger gaps. However, the direct suture is limited by heavy tension at the suture sites, and the autologous nerve graft also has the drawbacks of donor site morbidity and insufifcient donor tissue. Recently, artiifcial nerve conduits have been developed as an alternative for clinical nerve repair to overcome the limitations associated with the above treatments. In order to further improve the efifciency of nerve conduits, various guidance cues are incorporated, including physical cues, biochemical signals, as well as support cells. First, this paper reviewed the contact guidance cues applied in nerve conduits, such as lumen ifllers, multi-channels and micro-patterns on the inner surface. Then, the paper focused on the polymeric nerve conduits with micro inner grooves. The polymeric nerve conduits were fabricated using the phase inversion-based ifber spinning techniques. The smart spinneret with grooved die was designed in the spinning platform, while different spinning conditions, including flow rates, air-gap distances, and polymer concentrations, were adjusted to investigate the inlfuence of fabrication conditions on the geometry of nerve conduits. The inner groove size in the nerve conduits can be precisely controlled in our hollow ifber spinning process, which can work as the efifcient contact guidance cue for nerve regeneration.

  2. Biomechanical properties of acellular sciatic nerves treated with a modified chemical method

    Institute of Scientific and Technical Information of China (English)

    Xinlong Ma; Zhao Yang; Xiaolei Sun; Jianxiong Ma; Xiulan Li; Zhenzhen Yuan; Yang Zhang; Honggang Guo

    2011-01-01

    Nerve grafts are able to adapt to surrounding biomechanical environments if the nerve graft itself exhibits appropriate biomechanical properties (load, elastic modulus, etc.). The present study was designed to determine the differences in biomechanical properties between fresh and chemically acellularized sciatic nerve grafts. Two different chemical methods were used to establish acellular nerve grafts. The nerve was chemically extracted in the Sondell method with a combination of Triton X-100 (nonionic detergent) and sodium deoxycholate (anionic detergent), and in the modified method with a combination of Triton X-200 (anionic detergent), sulfobetaine-10 (SB-10, amphoteric detergents), and sulfobetaine-16 (SB-16, amphoteric detergents). Following acellularization, hematoxylin-eosin staining and scanning electron microscopy demonstrated that the effect of acellularization via the modified method was similar to the traditional Sondell method. However, effects of demyelination and nerve fiber tube integrity were superior to the traditional Sondell method. Biomechanical testing showed that peripheral nerve graft treated using the chemical method resulted in decreased biomechanical properties (ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture) compared with fresh nerves, but the differences had no statistical significance (P > 0.05). These results demonstrated no significant effect on biomechanical properties of nerves treated using the chemical method. In conclusion, nerve grafts treated via the modified method removed Schwann cells, preserved neural structures, and ensured biomechanical properties of the nerve graft, which could be more appropriate for implantation studies.

  3. Skin Graft

    OpenAIRE

    Ruka Shimizu; Kazuo Kishi

    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...

  4. Nerve conduction

    Science.gov (United States)

    ... the central nervous system (CNS) and peripheral nervous system (PNS). The CNS contains the brain and the spinal cord and the PNS consists of thousands of nerves that connect the spinal cord to muscles and sensory receptors. A peripheral nerve is composed of nerve ...

  5. Factors that influence peripheral nerve regeneration

    DEFF Research Database (Denmark)

    Krarup, Christian; Archibald, Simon J; Madison, Roger D

    2002-01-01

    median nerve lesions (n = 46) in nonhuman primates over 3 to 4 years, a time span comparable with such lesions in humans. Nerve gap distances of 5, 20, or 50mm were repaired with nerve grafts or collagen-based nerve guide tubes, and three electrophysiological outcome measures were followed: (1) compound...... as outcome predictors. Thus, nerve gap distance and repair type exert their influence through time to muscle reinnervation. These findings emphasize that factors that control early axonal outgrowth influence the final level of recovery attained years later. They also highlight that a time window...... muscle action potentials in the abductor pollicis brevis muscle, (2) the number and size of motor units in reinnervated muscle, and (3) compound sensory action potentials from digital nerve. A statistical model was used to assess the influence of three variables (repair type, nerve gap distance, and time...

  6. Biomechanical properties of peripheral nerve after acellular treatment

    Institute of Scientific and Technical Information of China (English)

    MA Xin-long; SUN Xiao-lei; YANG Zhao; LI Xiu-lan; MA Jian-xiong; ZHANG Yang; YUAN Zhen-zhen

    2011-01-01

    Background Peripheral nerve injury causes a high rate of disability and a huge economic burden,and is currently one of the serious health problems in the world.The use of nerve grafts plays a vital role in repairing nerve defects.Acellular nerve grafts have been widely used in many experimental models as a peripheral nerve substitute.The purpose of this study was to test the biomechanical properties of acellular nerve grafts.Methods Thirty-four fresh sciatic nerves were obtained from 17 adult male Wistar rats (age of 3 months) and randomly assigned to 3 groups:normal control group,nerve segments underwent no treatment and were put in phosphate buffered saline (pH 7.4) and stored at 4℃ until further use; physical method group,nerve segments were frozen at -196℃ and then thawed at 37℃; and chemical method group,nerve segments were chemically extracted with the detergents Triton X-200,sulfobetaine-10 (SB-10) and sulfobetaine-16 (SB-16).After the acellularization process was completed,the structural changes of in the sciatic nerves in each group were observed by hematoxylin-eosin staining and field emission scanning electron microscopy,then biomechanical properties were tested using a mechanical apparatus (Endura TEC ELF 3200,Bose,Boston,USA).Results Hematoxylin-eosin staining and field emission scanning electron microscopy demonstrated that the effects of acellularization,demyelination,and integrity of nerve fiber tube of the chemical method were better than that of the physical method.Biomechanical testing showed that peripheral nerve grafts treated with the chemical method resulted in some decreased biomechanical properties (ultimate load,ultimate stress,ultimate strain,and mechanical work to fracture) compared with normal control nerves,but the differences were not statistically significant (P >0.05).Conclusion Nerve treated with the chemical method may be more appropriate for use in implantation than nerve treated with the physical method.

  7. A silk sericin/silicone nerve guidance conduit promotes regeneration of a transected sciatic nerve.

    Science.gov (United States)

    Xie, Hongjian; Yang, Wen; Chen, Jianghai; Zhang, Jinxiang; Lu, Xiaochen; Zhao, Xiaobo; Huang, Kun; Li, Huili; Chang, Panpan; Wang, Zheng; Wang, Lin

    2015-10-28

    Peripheral nerve gap defects lead to significant loss of sensory or motor function. Tissue engineering has become an important alternative to nerve repair. Sericin, a major component of silk, is a natural protein whose value in tissue engineering has just begun to be explored. Here, the first time use of sericin in vivo is reported as a long-term implant for peripheral nerve regeneration. A sericin nerve guidance conduit is designed and fabricated. This conduit is highly porous with mechanical strength matching peripheral nerve tissue. It supports Schwann cell proliferation and is capable of up-regulating the transcription of glial cell derived neurotrophic factor and nerve growth factor in Schwann cells. The sericin conduit wrapped with a silicone conduit (sericin/silicone double conduits) is used for bridging repair of a 5 mm gap in a rat sciatic nerve transection model. The sericin/silicone double conduits achieve functional recovery comparable to that of autologous nerve grafting as evidenced by drastically improved nerve function and morphology. Importantly, this improvement is mainly attributed to the sericin conduit as the silicone conduit alone only produces marginal functional recovery. This sericin/silicone-double-conduit strategy offers an efficient and valuable alternative to autologous nerve grafting for repairing damaged peripheral nerve. PMID:26332703

  8. 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

    Directory of Open Access Journals (Sweden)

    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

  9. Terminal nerve: cranial nerve zero

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Duque Parra

    2006-12-01

    Full Text Available It has been stated, in different types of texts, that there are only twelve pairs of cranial nerves. Such texts exclude the existence of another cranial pair, the terminal nerve or even cranial zero. This paper considers the mentioned nerve like a cranial pair, specifying both its connections and its functional role in the migration of liberating neurons of the gonadotropic hormone (Gn RH. In this paper is also stated the hypothesis of the phylogenetic existence of a cerebral sector and a common nerve that integrates the terminal nerve with the olfactory nerves and the vomeronasals nerves which seem to carry out the odors detection function as well as in the food search, pheromone detection and nasal vascular regulation.

  10. Functioning transferred free muscle innervated by part of the vascularized ulnar nerve connecting the contralateral cervical seventh root to themedian nerve: Case report

    OpenAIRE

    Nakayama Ken; Ikeguchi Ryosuke; Kakinoki Ryosuke; Nakamura Takashi

    2007-01-01

    Abstract Background The limited nerve sources available for the reconstruction and restoration of upper extremity function is the biggest obstacle in the treatment of brachial plexus injury (BPI). We used part of a transplanted vascularized ulnar nerve as a motor source of a free muscle graft. Case presentation A 21-year-old man with a left total brachial plexus injury had received surgical intercostal nerve transfer to the musculocutaneous nerve and a spinal accessory nerve transfer to the s...

  11. 负压引流技术辅助人工真皮与自体皮移植修复关节开放和/或骨折处骨外露创面的临床研究%Clinical study on repair of open joint wounds and/or wounds with exposed bone fracture using negative pressure wound therapy combined with artificial dermis grafting and autologous skin grafting

    Institute of Scientific and Technical Information of China (English)

    陈欣; 王浩; 戴允东; 张琮; 王成

    2015-01-01

    Objective To explore the clinical effects of negative pressure wound therapy (NPWT)combined with artificial dermis grafting and autologous skin grafting on repair of open joint wounds and/or wounds with exposed bone fracture.Methods Eleven patients with open joint wounds and/or wounds with exposed bone fracture,hospitalized from November 2008 to November 2014,were enrolled in the study.According to the differences of the first stage treatment,all patients were divided into experimental group (n =6,including 4 patients of open joint wounds,1 patient of wound with exposed bone fracture,and Ⅰ patient of open joint wound with exposed bone fracture),and control group (n =5,including 2 patients of open joint wounds,2 patients of wounds with exposed bone fracture,and 1 patient of open joint wound with exposed bone fracture).After debridement,the wounds in both groups were grafted with punctured artificial dermis,while NPWT was only used over the artificial dermis of experiment group for 1 week.In the operation at second stage,autologous split-thickness skin was grafted on the vascularized artificial dermis in both groups.Results In 5 patients of open joint wounds in experimental group,the artificial dermis was vascularized well,autologous skin grafts survived,and wounds were healed.In 3 patients of open joint wounds in control group,the artificial dermis grafting all failed due to local infection,and then these wounds were repaired with local tissue flap grafting.Artificial dermis in 3 patients of wounds with exposed bone fracture in both groups was vascularized well after grafting,and the wounds were healed after autologous skin grafting,whether or not NPWT was used.Conclusions NPWT combined with artificial dermis grafting and autologous skin grafting can be used for repairing open joint wounds and/or wounds with exposed bone fracture.%目的 探讨应用负压引流技术辅助人工真皮和自体皮移植修复关节开放和/或骨折处

  12. Surgical outcomes following nerve transfers in upper brachial plexus injuries

    Directory of Open Access Journals (Sweden)

    Bhandari P

    2009-01-01

    Full Text Available Background: Brachial plexus injuries represent devastating injuries with a poor prognosis. Neurolysis, nerve repair, nerve grafts, nerve transfer, functioning free-muscle transfer and pedicle muscle transfer are the main surgical procedures for treating these injuries. Among these, nerve transfer or neurotization is mainly indicated in root avulsion injury. Materials and Methods: We analysed the results of various neurotization techniques in 20 patients (age group 20-41 years, mean 25.7 years in terms of denervation time, recovery time and functional results. The inclusion criteria for the study included irreparable injuries to the upper roots of brachial plexus (C5, C6 and C7 roots in various combinations, surgery within 10 months of injury and a minimum follow-up period of 18 months. The average denervation period was 4.2 months. Shoulder functions were restored by transfer of spinal accessory nerve to suprascapular nerve (19 patients, and phrenic nerve to suprascapular nerve (1 patient. In 11 patients, axillary nerve was also neurotized using different donors - radial nerve branch to the long head triceps (7 patients, intercostal nerves (2 patients, and phrenic nerve with nerve graft (2 patients. Elbow flexion was restored by transfer of ulnar nerve motor fascicle to the motor branch of biceps (4 patients, both ulnar and median nerve motor fascicles to the biceps and brachialis motor nerves (10 patients, spinal accessory nerve to musculocutaneous nerve with an intervening sural nerve graft (1 patient, intercostal nerves (3rd, 4th and 5th to musculocutaneous nerve (4 patients and phrenic nerve to musculocutaneous nerve with an intervening graft (1 patient. Results: Motor and sensory recovery was assessed according to Medical Research Council (MRC Scoring system. In shoulder abduction, five patients scored M4 and three patients M3+. Fair results were obtained in remaining 12 patients. The achieved abduction averaged 95 degrees (range, 50 - 170

  13. Bone Grafts

    Science.gov (United States)

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

  14. Terminal nerve: cranial nerve zero

    OpenAIRE

    Jorge Eduardo Duque Parra; Carlos Alberto Duque Parra

    2006-01-01

    It has been stated, in different types of texts, that there are only twelve pairs of cranial nerves. Such texts exclude the existence of another cranial pair, the terminal nerve or even cranial zero. This paper considers the mentioned nerve like a cranial pair, specifying both its connections and its functional role in the migration of liberating neurons of the gonadotropic hormone (Gn RH). In this paper is also stated the hypothesis of the phylogenetic existence of a cerebral sector and a co...

  15. Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

    Directory of Open Access Journals (Sweden)

    Yasuhiko Onishi

    2014-12-01

    Full Text Available The anticancer efficacy of a supramolecular complex that was used as an artificial enzyme against multi-drug-resistant cancer cells was confirmed. A complex of diethylaminoethyl–dextran–methacrylic acid methylester copolymer (DDMC/paclitaxel (PTX, obtained with PTX as the guest and DDMC as the host, formed a nanoparticle 50–300 nm in size. This complex is considered to be useful as a drug delivery system (DDS for anticancer compounds since it formed a stable polymeric micelle in water. The resistance of B16F10 melanoma cells to PTX was shown clearly through a maximum survival curve. Conversely, the DDMC/PTX complex showed a superior anticancer efficacy and cell killing rate, as determined through a Michaelis–Menten-type equation, which may promote an allosteric supramolecular reaction to tubulin, in the same manner as an enzymatic reaction. The DDMC/PTX complex showed significantly higher anticancer activity compared to PTX alone in mouse skin in vivo. The median survival times of the saline, PTX, DDMC/PTX4 (particle size 50 nm, and DDMC/PTX5 (particle size 290 nm groups were 120 h (treatment (T/control (C, 1.0, 176 h (T/C, 1.46, 328 h (T/C, 2.73, and 280 h (T/C, 2.33, respectively. The supramolecular DDMC/PTX complex showed twice the effectiveness of PTX alone (p < 0.036. Above all, the DDMC/PTX complex is not degraded in cells and acts as an intact supramolecular assembly, which adds a new species to the range of DDS.

  16. In vivo generation of a mature and functional artificial skeletal muscle.

    Science.gov (United States)

    Fuoco, Claudia; Rizzi, Roberto; Biondo, Antonella; Longa, Emanuela; Mascaro, Anna; Shapira-Schweitzer, Keren; Kossovar, Olga; Benedetti, Sara; Salvatori, Maria L; Santoleri, Sabrina; Testa, Stefano; Bernardini, Sergio; Bottinelli, Roberto; Bearzi, Claudia; Cannata, Stefano M; Seliktar, Dror; Cossu, Giulio; Gargioli, Cesare

    2015-04-01

    Extensive loss of skeletal muscle tissue results in mutilations and severe loss of function. In vitro-generated artificial muscles undergo necrosis when transplanted in vivo before host angiogenesis may provide oxygen for fibre survival. Here, we report a novel strategy based upon the use of mouse or human mesoangioblasts encapsulated inside PEG-fibrinogen hydrogel. Once engineered to express placental-derived growth factor, mesoangioblasts attract host vessels and nerves, contributing to in vivo survival and maturation of newly formed myofibres. When the graft was implanted underneath the skin on the surface of the tibialis anterior, mature and aligned myofibres formed within several weeks as a complete and functional extra muscle. Moreover, replacing the ablated tibialis anterior with PEG-fibrinogen-embedded mesoangioblasts also resulted in an artificial muscle very similar to a normal tibialis anterior. This strategy opens the possibility for patient-specific muscle creation for a large number of pathological conditions involving muscle tissue wasting. PMID:25715804

  17. Microvascular Cranial Nerve Palsy

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Microvascular Cranial Nerve Palsy Sections What Is Microvascular Cranial Nerve Palsy? ... Microvascular Cranial Nerve Palsy Treatment What Is Microvascular Cranial Nerve Palsy? Aug. 02, 2012 Microvascular cranial nerve palsy ( ...

  18. The role of exosomes in peripheral nerve regeneration

    Directory of Open Access Journals (Sweden)

    Rosanna C Ching

    2015-01-01

    Full Text Available Peripheral nerve injuries remain problematic to treat, with poor functional recovery commonly observed. Injuries resulting in a nerve gap create specific difficulties for axonal regeneration. Approaches to address these difficulties include autologous nerve grafts (which are currently the gold standard treatment and synthetic conduits, with the latter option being able to be impregnated with Schwann cells or stem cells which provide an appropriate micro-environment for neuronal regeneration to occur. Transplanting stem cells, however, infers additional risk of malignant transformation as well as manufacturing difficulties and ethical concerns, and the use of autologous nerve grafts and Schwann cells requires the sacrifice of a functioning nerve. A new approach utilizing exosomes, secreted extracellular vesicles, could avoid these complications. In this review, we summarize the current literature on exosomes, and suggest how they could help to improve axonal regeneration following peripheral nerve injury.

  19. Neurotization of oculomotor, trochlear and abducent nerves in skull base surgery

    Institute of Scientific and Technical Information of China (English)

    李世亭; 潘庆刚; 刘宁涛; 刘忠; 沈峰

    2003-01-01

    Objective To anatomically reconstruct the oculomotor nerve, trochlear nerve, and abducent nerve by skull base surgery. Methods Seventeen cranial nerves (three oculomotor nerves, eight trochlear nerves and six abducent nerves) were injured and anatomically reconstructed in thirteen skull base operations during a period from 1994 to 2000. Repair techniques included end-to-end neurosuture or fibrin glue adhesion, graft neurosuture or fibrin glue adhesion. The relationships between repair techniques and functional recovery and the related factors were analyzed.Results Functional recovery began from 3 to 8 months after surgery. During a follow-up period of 4 months to 6 years, complete recovery of function was observed in 6 trochlear nerves (75%) and 4 abducent nerves (67%), while partial functional recovery was observed in the other cranial nerves including 2 trochlear nerves, 2 abducent nerves, and 3 oculomotor nerves.Conclusions Complete or partial functional recovery could be expected after anatomical neurotization of an injured oculomotor, trochlear or abducent nerve. Our study demonstrated that, in terms of functional recovery, trochlear and abducent nerves are more responsive than oculomotor nerves, and that end-to-end reconstruction is more efficient than graft reconstruction. These results encourage us to perform reconstruction for a separated cranial nerve as often as possible during skull base surgery.

  20. Neuroma of medial dorsal cutaneous nerve of superficial peroneal nerve after ankle arthroscopy.

    Science.gov (United States)

    Shim, Jae Sun; Lee, Ji Hyun; Han, Soo Hong; Kim, MinYoung; Lee, Hang Jae; Min, Kyunghoon

    2014-09-01

    Superficial peroneal neuropathy is a known complication of foot and ankle arthroscopy. A 27-year-old man developed pain and paresthesia on the medial side of the dorsum of his left foot after ankle arthroscopy. An electrodiagnostic study revealed conduction abnormality in the medial branch of superficial peroneal nerve, in which neuroma-in-continuity was subsequently detected by ultrasonography. After neuroma excision and nerve graft, the subject's neuropathic pain was substantially improved. PMID:24486918

  1. In vivo MRI monitoring nerve regeneration of acute peripheral nerve traction injury following mesenchymal stem cell transplantation

    International Nuclear Information System (INIS)

    Objective: To assess the continuous process of nerve regeneration in acute peripheral nerve traction injury treated with mesenchymal stem cells (MSCs) transplantation using MRI. Materials and methods: 1 week after acute nerve traction injury was established in the sciatic nerve of 48 New Zealand white rabbits, 5 × 105 MSCs and vehicle alone were grafted to the acutely distracted sciatic nerves each in 24 animals. Serial MRI and T1 and T2 measurements of the injured nerves were performed with a 1.5-T scanner and functional recovery was recorded over a 10-week follow-up period, with histological assessments performed at regular intervals. Results: Compared with vehicle control, nerves grafted with MSCs had better functional recovery and showed improved nerve regeneration, with a sustained increase of T1 and T2 values during the phase of regeneration. Conclusion: MRI could be used to monitor the enhanced nerve regeneration in acute peripheral nerve traction injury treated with MSC transplantation, reflected by a prolonged increase in T1 and T2 values of the injured nerves

  2. In vivo MRI monitoring nerve regeneration of acute peripheral nerve traction injury following mesenchymal stem cell transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Xiao-Hui, E-mail: duanxiaohui-128@163.com [Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China); Cheng, Li-Na, E-mail: kobe10716@163.com [Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China); Zhang, Fang, E-mail: xinxin110007@yahoo.com.cn [Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China); Liu, Jun, E-mail: docliujun@hotmail.com [Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China); Guo, Ruo-Mi, E-mail: guoruomi-521@163.com [Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China); Zhong, Xiao-Mei, E-mail: enough300@yahoo.com.cn [Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China); Wen, Xue-Hua, E-mail: xuehuasuqian@126.com [Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China); Shen, Jun, E-mail: junshenjun@hotmail.com [Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong (China)

    2012-09-15

    Objective: To assess the continuous process of nerve regeneration in acute peripheral nerve traction injury treated with mesenchymal stem cells (MSCs) transplantation using MRI. Materials and methods: 1 week after acute nerve traction injury was established in the sciatic nerve of 48 New Zealand white rabbits, 5 × 10{sup 5} MSCs and vehicle alone were grafted to the acutely distracted sciatic nerves each in 24 animals. Serial MRI and T1 and T2 measurements of the injured nerves were performed with a 1.5-T scanner and functional recovery was recorded over a 10-week follow-up period, with histological assessments performed at regular intervals. Results: Compared with vehicle control, nerves grafted with MSCs had better functional recovery and showed improved nerve regeneration, with a sustained increase of T1 and T2 values during the phase of regeneration. Conclusion: MRI could be used to monitor the enhanced nerve regeneration in acute peripheral nerve traction injury treated with MSC transplantation, reflected by a prolonged increase in T1 and T2 values of the injured nerves.

  3. Stent graft placement for dysfunctional arteriovenous grafts

    International Nuclear Information System (INIS)

    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

  4. Stent graft placement for dysfunctional arteriovenous grafts

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Estimulação elétrica nervosa transcutânea após cirurgia de revascularização miocárdica Transcutaneous electrical nerve stimulation after coronary artery bypass graft surgery

    Directory of Open Access Journals (Sweden)

    Paula Monique Barbosa Lima

    2011-12-01

    Full Text Available INTRODUÇÃO: Após a cirurgia cardíaca, os pacientes apresentam limitação na força muscular respiratória, o que favorece a instalação de complicações pulmonares. OBJETIVO: Analisar a eficácia da estimulação elétrica nervosa transcutânea sobre o processo doloroso e força muscular respiratória em pacientes submetidos à cirurgia de revascularização do miocárdio (CRM. MÉTODOS: Foram inclusos pacientes em pós-operatório de CRM por meio de esternotomia, com uso de circulação extracorpórea, anestesia geral, sem estar sob efeito de bloqueio neuromuscular, uso de drenos de tórax e mediastino, extubados até 6 horas pós-procedimento e apresentando índice igual ou superior a três na escala analógica visual da dor (EVA, estando no primeiro dia de pós-operatório (1º DPO. Foram recrutados 20 pacientes, divididos em dois grupos, sem predomínio de sexo: Grupo Controle (n=10, que recebeu terapia analgésica mais fisioterapia; e Grupo TENS, que recebeu terapia analgésica, fisioterapia e TENS. A TENS foi aplicada por 30 minutos, três vezes ao dia, num intervalo de 3 horas cada aplicação. RESULTADOS: Para o grau de dor, houve uma média inicial e final, respectivamente, de 7,0 e 1,0 para o Grupo TENS e 7,0 e 8,0 para o Grupo Controle. Para a Pimáx, a média inicial e final foi de, respectivamente, -102,5 cmH2O e -141,17 cmH2O para o Grupo TENS e -97,0 cmH2O e -100,3 cmH2O para o Controle. Quanto a Pemáx, a média inicial e final foi de, respectivamente, 63 cmH2O e 125 cmH2O para o Grupo TENS e 55,3 cmH2O e 53,2 cmH2O para o Grupo Controle. CONCLUSÃO: A TENS demonstrou eficácia significativa na redução da algia e no aumento das forças musculares respiratórias no 1º DPO de CRM.INTRODUCTION: After cardiac surgery, patients have a limitation in respiratory muscle strength, which favors the appearing of pulmonary complications. OBJECTIVE: To evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS

  6. An experimental study of artificial murine bladder reflex arc established by abdominal reflex

    Institute of Scientific and Technical Information of China (English)

    WANG Jin-wu; ZHAO Yu-wu; HOU Chun-lin; NI Wei-feng; RUI Bi-yu; GUO Shang-chun; ZHENG Xian-you; DAI Ke-rong

    2011-01-01

    Background The neurogenic bladder dysfunction caused by spinal cord injury is difficult to treat clinically. The aim of this research was to establish an artificial bladder reflex arc in rats through abdominal reflex pathway above the level of spinal cord injury, reinnervate the neurogenic bladder and restore bladder micturition.Methods The outcome was achieved by intradural microanastomosis of the right T13 ventral root to S2 ventral root with autogenous nerve grafting, leaving the right T13 dorsal root intact. Long-term function of the reflex arc was assessed from nerve electrophysiological data and intravesical pressure tests during 8 months postoperation. Horseradish peroxidase (HRP) tracing was performed to observe the effectiveness of the artificial reflex.Results Single stimulus (3 mA, 0.3 ms pulses, 20 Hz, 5-second duration) on the right T13 dorsal root resulted in evoked action potentials, raised intravesical pressures and bladder smooth muscle, compound action potential recorded from the right vesical plexus before and after the spinal cord transaction injury between L5 and S4 segmental in 12 Sprague-Dawley rats. There were HRP labelled cells in T13 ventral horn on the experimental side and in the intermediolateral nucleus on both sides of the L6-S4 segments after HRP injection. There was no HRP labelled cell in T13 ventral horn on the control side.Conclusion Using the surviving somatic reflex above the level of spinal cord injury to reconstruct the bladder autonomous reflex arc by intradural microanastomosis of ventral root with a segment of autologous nerve grafting is practical in rats and may have clinical applications for humans.

  7. Cutaneous nerve entrapment syndrome

    Institute of Scientific and Technical Information of China (English)

    DongFuhui

    2004-01-01

    The cutaneous nerve entrapment syndrome is named that, the cutaneous nerve's functional disorder caused by some chronic entrapment, moreover appears a series of nerve's feeling obstacle,vegetative nerve function obstacle, nutrition obstacle, even motor function obstacle in various degree.

  8. Nerve biopsy (image)

    Science.gov (United States)

    Nerve biopsy is the removal of a small piece of nerve for examination. Through a small incision, a sample ... is removed and examined under a microscope. Nerve biopsy may be performed to identify nerve degeneration, identify ...

  9. Bridging sciatic nerve gap using tissue-engineered nerves constructed with neural tissue-committed stem cells derived from bone marrow

    Institute of Scientific and Technical Information of China (English)

    Zhiying Zhang; Congli Ren; Chuansen Zhang; Fang Liu; Liang Li

    2009-01-01

    BACKGROUND: Schwann cells are the most commonly used cells for tissue-engineered nerves. However, autologous Schwann cells are of limited use in a clinical context, and allogeneic Schwann cells induce immunological rejections. Cells that do not induce immunological rejections and that are relatively easy to acquire are urgently needed for transplantation.OBJECTIVE: To bridge sciatic nerve defects using tissue engineered nerves constructed with neural tissue-committed stem cells (NTCSCs) derived from bone marrow; to observe morphology and function of rat nerves following bridging; to determine the effect of autologous nerve transplantation, which serves as the gold standard for evaluating efficacy of tissue-engineered nerves.DESIGN, TIME AND SETTING: This randomized, controlled, animal experiment was performed in the Anatomical laboratory and Biomedical Institute of the Second Military Medical University of Chinese PLA between September 2004 and April 2006.MATERIALS: Five Sprague Dawley rats, aged 1 month and weighing 100-150 g, were used for cell culture. Sixty Sprague Dawiey rats aged 3 months and weighing 220-250 g, were used to establish neurological defect models. Nestin, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), and S-100 antibodies were provided by Santa Cruz Biotechnology, Inc., USA. Acellular nerve grafts were derived from dogs.METHODS: All rats, each with 1-cm gap created in the right sciatic nerve, were randomly assigned to three groups. Each group comprised 20 rats. Autograft nerve transplantation group: the severed 1-cm length nerve segment was reverted, but with the two ends exchanged; the proximal segment was sutured to the distal sciatic nerve stump and the distal segment to the proximal stump. Blank nerve scaffold transplantation group: a 1-cm length acellular nerve graft was used to bridge the sciatic nerve gap. NTCSC engineered nerve transplantation group: a 1-cm length acellular nerve graft, in which NTCSCs were

  10. Surgical treatment of painful lesions of the inferior alveolar nerve.

    Science.gov (United States)

    Biglioli, Federico; Allevi, Fabiana; Lozza, Alessandro

    2015-10-01

    Nerve-related complications are being reported with increasing frequency following oral and dental surgery, and typically involve the inferior alveolar nerve (IAN). We assess herein the etiology of neuropathic pain related to IAN injuries, and describe the various surgical treatment techniques available. Between 2007 and 2013, 19 patients were referred to the Maxillofacial Surgery Department of San Paolo Hospital (Milan, Italy) with pain in the area supplied by the IAN, which developed following endodontic treatment, oral surgery and maxillofacial surgery. All patients underwent IAN surgery by several different microsurgical procedures. Most of the patients affected by pain before surgery experienced complete or partial amelioration of symptoms. All patients receiving sural nerve grafts were pain-free 12 months after surgery. In five patients the operation was unsuccessful. In 78.94% of cases, a significant increase in nerve function was observed. Pain following IAN surgical damage may be addressed by microsurgery; nerve substitution with a sural nerve interpositional graft appears to represent the most efficacious procedure. Scar releasing, nerve decompression and nerve substitution using vein grafts are less effective. Removal of endodontic material extravasated into the mandibular canal is mandatory and effective in patients experiencing severe pain. Surgery should be performed within 12 months postoperatively, ideally during the first few weeks after symptoms onset. PMID:26315275

  11. Nerve Transfers in Birth Related Brachial Plexus Injuries: Where Do We Stand?

    Science.gov (United States)

    Davidge, Kristen M; Clarke, Howard M; Borschel, Gregory H

    2016-05-01

    This article reviews the assessment and management of obstetrical brachial plexus palsy. The potential role of distal nerve transfers in the treatment of infants with Erb's palsy is discussed. Current evidence for motor outcomes after traditional reconstruction via interpositional nerve grafting and extraplexal nerve transfers is reviewed and compared with the recent literature on intraplexal distal nerve transfers in obstetrical brachial plexus injury. PMID:27094890

  12. Development of biomaterial scaffold for nerve tissue engineering: Biomaterial mediated neural regeneration

    OpenAIRE

    Sethuraman Swaminathan; Krishnan Uma; Subramanian Anuradha

    2009-01-01

    Abstract Neural tissue repair and regeneration strategies have received a great deal of attention because it directly affects the quality of the patient's life. There are many scientific challenges to regenerate nerve while using conventional autologous nerve grafts and from the newly developed therapeutic strategies for the reconstruction of damaged nerves. Recent advancements in nerve regeneration have involved the application of tissue engineering principles and this has evolved a new pers...

  13. Artificial nerve system for structural monitoring

    Science.gov (United States)

    Martin, William N., Jr.; Ghoshal, Anindya; Sundaresan, Mannur J.; Lebby, Gary L.; Schulz, Mark J.; Pratap, Promod R.

    2002-06-01

    Recent structural health monitoring techniques have focused on developing global sensor systems that can detect damage on large structures. The approach presented here uses a piezoelectric sensor array system that mimics the biological nervous system architecture to measure acoustic emissions and dynamic strains in structures. The advantage of this approach is that the number of channels of data acquisition used for an N-by-N sensor array can be reduced from N2 to 2N. For large arrays the number of data acquisition channels is tremendously reduced. When transient damage events occur on the structure, the array output time histories can be recorded and the location of the excitation can be accurately determined using combinatorial logic. A trade-off is the difficulty of extracting individual sensor time histories from the array outputs without a neural network or a regressive technique. Only the sums of the sensor strains of each row and column can be exactly calculated using the voltage outputs of the array. The array approach allows efficient use of data acquisition instrumentation for structural health monitoring. Applications for the sensor array include crack and delamination detection, dynamic strain measurement, impact detection, and localization of damage on large complex structures.

  14. Imaging of muscular denervation secondary to motor cranial nerve dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Connor, S.E.J. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom)]. E-mail: sejconnor@tiscali.co.uk; Chaudhary, N. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Fareedi, S. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Woo, E.K. [Neuroradiology Department, Kings College Hospital, Denmark Hill, London SE5 9RS (United Kingdom)

    2006-08-15

    The effects of motor cranial nerve dysfunction on the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of head and neck muscles are reviewed. Patterns of denervation changes are described and illustrated for V, VII, X, XI and XII cranial nerves. Recognition of the range of imaging manifestations, including the temporal changes in muscular appearances and associated muscular grafting or compensatory hypertrophy, will avoid misinterpretation as local disease. It will also prompt the radiologist to search for underlying cranial nerve pathology, which may be clinically occult. The relevant cranial nerve motor division anatomy will be described to enable a focussed search for such a structural abnormality.

  15. Imaging of muscular denervation secondary to motor cranial nerve dysfunction

    International Nuclear Information System (INIS)

    The effects of motor cranial nerve dysfunction on the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of head and neck muscles are reviewed. Patterns of denervation changes are described and illustrated for V, VII, X, XI and XII cranial nerves. Recognition of the range of imaging manifestations, including the temporal changes in muscular appearances and associated muscular grafting or compensatory hypertrophy, will avoid misinterpretation as local disease. It will also prompt the radiologist to search for underlying cranial nerve pathology, which may be clinically occult. The relevant cranial nerve motor division anatomy will be described to enable a focussed search for such a structural abnormality

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

    OpenAIRE

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

    2014-01-01

    We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerv...

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

    OpenAIRE

    2014-01-01

    We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve...

  18. Endothelialized ePTFE Graft by Nanobiotechnology

    Science.gov (United States)

    2013-11-29

    The Apparatus for Processing the Tubular Graft Modification Will be Designed and Evaluated.; The On-site Capturing of the Endothelial (Progenitor) Cells by Peptide-mediated Selective Adhesion in Vitro and in Vivo Will Also be Elucidated.; The Patency Rate of ITRI-made Artificial Blood Vessels Will be Evaluated by the Porcine Animal Model.

  19. Polyethylene glycol-grafted polystyrene particles

    NARCIS (Netherlands)

    Meng, Fenghua; Engbers, Gerard H.M.; Feijen, Jan

    2004-01-01

    Densely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS-COOH) using carbodiimide chemistry. PEG-modified particles (PS-PEG) were chara

  20. Using Eggshell Membrane as Nerve Guide Channels in Peripheral Nerve Regeneration

    Directory of Open Access Journals (Sweden)

    Gholam Hossein Farjah

    2013-08-01

    Full Text Available Objective(s:  The aim of this study was to evaluate the final outcome of nerve regeneration across the eggsell membrane (ESM tube conduit in comparison with autograft. Materials and Methods: Thirty adult male rats (250-300 g were randomized into (1 ESM conduit, (2 autograft, and (3 sham surgery groups. The eggs submerged in 5% acetic acid. The decalcifying membranes were cut into four pieces, rotated over the teflon mandrel and dried at   37°C. The left sciatic nerve was surgically cut. A 10-mm nerve segment was cut and removed. In the ESM group, the proximal and distal cut ends of the sciatic nerve were telescoped into the nerve guides. In the autograft group, the 10 mm nerve segment was reversed and used as an autologous nerve graft. All animals were evaluated by sciatic functional index (SFI and electrophysiology testing.  Results:The improvement in SFI from the first to the last evalution in ESM and autograft groups were evaluated. On days 49 and 60 post-operation, the mean SFI of ESM group was significantly greater than the autograft group (P 0.05. Conclusion:These findings demonstrate that ESM effectively enhances nerve regeneration and promotes functional recovery in injured sciatic nerve of rat.

  1. Peripheral nerve conduits: technology update

    Directory of Open Access Journals (Sweden)

    Arslantunali D

    2014-12-01

    Full Text Available D Arslantunali,1–3,* T Dursun,1,2,* D Yucel,1,4,5 N Hasirci,1,2,6 V Hasirci,1,2,7 1BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University (METU, Ankara, Turkey; 2Department of Biotechnology, METU, Ankara, Turkey; 3Department of Bioengineering, Gumushane University, Gumushane, Turkey; 4Faculty of Engineering, Department of Medical Engineering, Acibadem University, Istanbul, Turkey; 5School of Medicine, Department of Histology and Embryology, Acibadem University, Istanbul, Turkey; 6Department of Chemistry, Faculty of Arts and Sciences, METU, Ankara, Turkey; 7Department of Biological Sciences, Faculty of Arts and Sciences, METU, Ankara, Turkey *These authors have contributed equally to this work Abstract: Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers and designs (tubular, fibrous, and matrix type are being presented. Keywords: peripheral nerve injury, natural biomaterials, synthetic biomaterials

  2. Repairing Peripheral Nerves: Is there a Role for Carbon Nanotubes?

    Science.gov (United States)

    Oprych, Karen M; Whitby, Raymond L D; Mikhalovsky, Sergey V; Tomlins, Paul; Adu, Jimi

    2016-06-01

    Peripheral nerve injury continues to be a major global health problem that can result in debilitating neurological deficits and neuropathic pain. Current state-of-the-art treatment involves reforming the damaged nerve pathway using a nerve autograft. Engineered nerve repair conduits can provide an alternative to the nerve autograft avoiding the inevitable tissue damage caused at the graft donor site. Commercially available nerve repair conduits are currently only considered suitable for repairing small nerve lesions; the design and performance of engineered conduits requires significant improvements to enable their use for repairing larger nerve defects. Carbon nanotubes (CNTs) are an emerging novel material for biomedical applications currently being developed for a range of therapeutic technologies including scaffolds for engineering and interfacing with neurological tissues. CNTs possess a unique set of physicochemical properties that could be useful within nerve repair conduits. This progress report aims to evaluate and consolidate the current literature pertinent to CNTs as a biomaterial for supporting peripheral nerve regeneration. The report is presented in the context of the state-of-the-art in nerve repair conduit design; outlining how CNTs may enhance the performance of next generation peripheral nerve repair conduits. PMID:27027923

  3. Pre-differentiation of mesenchymal stromal cells in combination with a microstructured nerve guide supports peripheral nerve regeneration in the rat sciatic nerve model.

    Science.gov (United States)

    Boecker, Arne Hendrik; van Neerven, Sabien Geraldine Antonia; Scheffel, Juliane; Tank, Julian; Altinova, Haktan; Seidensticker, Katrin; Deumens, Ronald; Tolba, Rene; Weis, Joachim; Brook, Gary Anthony; Pallua, Norbert; Bozkurt, Ahmet

    2016-02-01

    Many bioartificial nerve guides have been investigated pre-clinically for their nerve regeneration-supporting function, often in comparison to autologous nerve transplantation, which is still regarded as the current clinical gold standard. Enrichment of these scaffolds with cells intended to support axonal regeneration has been explored as a strategy to boost axonal regeneration across these nerve guides Ansselin et al. (1998). In the present study, 20 mm rat sciatic nerve defects were implanted with a cell-seeded microstructured collagen nerve guide (Perimaix) or an autologous nerve graft. Under the influence of seeded, pre-differentiated mesenchymal stromal cells, axons regenerated well into the Perimaix nerve guide. Myelination-related parameters, like myelin sheath thickness, benefitted from an additional seeding with pre-differentiated mesenchymal stromal cells. Furthermore, both the number of retrogradely labelled sensory neurons and the axon density within the implant were elevated in the cell-seeded scaffold group with pre-differentiated mesenchymal stromal cells. However, a pre-differentiation had no influence on functional recovery. An additional cell seeding of the Perimaix nerve guide with mesenchymal stromal cells led to an extent of functional recovery, independent of the differentiation status, similar to autologous nerve transplantation. These findings encourage further investigations on pre-differentiated mesenchymal stromal cells as a cellular support for peripheral nerve regeneration. PMID:26296589

  4. Methods to evaluate functional nerve recovery in adult rats : walking track analysis, video analysis and the withdrawal reflex

    NARCIS (Netherlands)

    Dijkstra, [No Value; Meek, MF; Robinson, PH; Gramsbergen, A

    2000-01-01

    The aim of this study was to compare different methods for the evaluation of functional nerve recovery. Three groups of adult male Wistar rats were studied. In group A, a 12-mm gap between nerve ends was bridged by an autologous nerve graft; in rats of group B we performed a crush lesion of the scia

  5. Artificial organs: recent progress in artificial hearing and vision.

    Science.gov (United States)

    Ifukube, Tohru

    2009-01-01

    Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas. PMID:19330498

  6. Ascorbic acid improves embryonic cardiomyoblast cell survival and promotes vascularization in potential myocardial grafts in vivo

    OpenAIRE

    Martinez, E. C.; Wang, J; Gan, S U; Singh, R.; Lee, C. N.; Kofidis, T

    2010-01-01

    Organ restoration via cell therapy and tissue transplantation is limited by impaired graft survival. We tested the hypothesis that ascorbic acid (AA) reduces cell death in myocardial grafts both in vitro and in vivo and introduced a new model of autologous graft vascularization for later transplantation. Luciferase (Fluc)- and green fluorescent protein (GFP)-expressing H9C2 cardiomyoblasts were seeded in gelatin scaffolds to form myocardial artificial grafts (MAGs). MAGs were supplemented wit...

  7. The thrombogenicity of Dacron arterial grafts and its modification by platelet inhibitory drugs.

    OpenAIRE

    Kester, R. C.

    1984-01-01

    When blood flows through Dacron arterial grafts, platelets adhere in large numbers to the luminal surface of the grafts. Different types of commercially available Dacron grafts vary in their level of thrombogenicity. This thrombogenic response has been evaluated in an artificial circulation and in patients with Dacron aorto-bifemoral grafts, and the response can be modified by the use of platelet-inhibitory drugs. A double blind trial has shown that when a combination of aspirin and dipyridam...

  8. Controlled Delivery of FK506 to Improve Nerve Regeneration.

    Science.gov (United States)

    Labroo, Pratima; Ho, Scott; Sant, Himanshu; Shea, Jill; Gale, Bruce K; Agarwal, Jay

    2016-09-01

    Autologous nerve grafts are the current "gold standard" for repair of large nerve gaps. However, they cause morbidity at the donor nerve site, only a limited amount of nerve can be harvested, and there is the potential for mismatches in size and fascicular patterns between the nerve stumps and the graft. Nerve conduits are a promising alternative to autografts and can act as guidance cues for the regenerating axons and allow for tension free bridging, without the need to harvest donor nerve. Separately, FK506, and FDA-approved small molecule, has been shown to enhance axon growth and peripheral nerve regeneration. This article describes the design of a novel drug delivery apparatus integrated with a poly lactic-co-glycolic acid (PLGA)-based nerve guide conduit for controlled local delivery of FK506. An FK506 dosage curve was acquired to determine the minimum in vitro concentration for optimal axonal outgrowth of dorsal root ganglion (DRG) cells, then PLGA devices were designed and tested in a diffusion chamber, and finally the bioactivity of the released media was evaluated by measuring axon growth in DRG cells exposed to the media for 72 h. The combined drug delivery nerve guide was able to release FK506 for 20 days at concentrations (1-20 ng/mL) that were shown to enhance DRG axon growth. Furthermore, the released FK506 was bioactive and able to enhance DRG axon growth. The combined drug delivery nerve guide can release FK506 for extended periods of time and enhance axon growth, and has the potential to improve nerve regeneration after a peripheral nerve injury. PMID:27058050

  9. Adenoid cystic carcinoma of the parotid gland: Anastamosis of the facial nerve with the great auricular nerve after radical parotidectomy

    Directory of Open Access Journals (Sweden)

    Bahadir Osman

    2008-01-01

    Full Text Available Adenoid cystic carcinoma of the parotid gland is a rare and slowly growing, but highly malignant tumor. Surgical resection of a malignant parotid tumor should include resection of the facial nerve when the nerve is involved in the tumor. Facial nerve reconstruction is required after nerve resection. A 14 year-old female presented with complaints of painless enlargement of the right parotid gland and facial asymmetry. Physical examination revealed a firm mass in the region of the parotid gland as well as right facial paralysis. Biopsy obtained from the mass showed an adenoid cystic carcinoma of the parotid gland. A radical parotidectomy with a modified radical neck dissection was carried out. Grafting material for the facial reconstruction was harvested from the great auricular nerve. The proximal main trunk and each distal branch of the facial nerve were coapted with the greater auricular nerve. The patient received radiotherapy after surgery and was seen to achieve grade IV facial function one year after surgery. Thus, the great auricular nerve is appropriate grafting material for coaptation of each distal branch of the facial nerve.

  10. Nerve transfer for treatment of brachial plexus injury: comparison study between the transfer of partial median and ulnar nerves and that of phrenic and spinal accessary nerves

    Institute of Scientific and Technical Information of China (English)

    侯之启; 徐中和

    2002-01-01

    Objective: To compare the effect of using partial median and ulnar nerves for treatment of C5-6 or C5-7 avulsion of the brachial plexus with that of using phrenic and spinal accessary nerves.Methods: The patients were divided into 2 groups randomly according to different surgical procedures. Twelve cases were involved in the first group. The phrenic nerve was transferred to the musculocutaneous nerve or through a sural nerve graft, and the spinal accessary nerve was to the suprascapular nerve. Eleven cases were classified into the second group. A part of the fascicles of median nerve was transferred to be coapted with the motor fascicle of musculocutaneous nerve and a part of fascicles of ulnar nerve was transferred to the axillary nerve. The cases were followed up from 1 to 3 years and the clinical outcome was compared between the two groups. Results: There were 2 cases (16.6%) who got the recovery of M4 strength of biceps muscle in the first group but 7 cases (63.6%) in the second group, and the difference was statistically significant (P<0.025). However, it was not statistically different in the recovery of shoulder function between the two groups. Conclusions: Partial median and ulnar nerve transfer, phrenic and spinal accessary nerve transfer were all effective for the reconstruction of elbow or shoulder function in brachial plexus injury, but the neurotization using a part of median nerve could obtain more powerful biceps muscle strength than that of phrenic nerve transfer procedure.

  11. Artificial intelligence

    CERN Document Server

    Hunt, Earl B

    1975-01-01

    Artificial Intelligence provides information pertinent to the fundamental aspects of artificial intelligence. This book presents the basic mathematical and computational approaches to problems in the artificial intelligence field.Organized into four parts encompassing 16 chapters, this book begins with an overview of the various fields of artificial intelligence. This text then attempts to connect artificial intelligence problems to some of the notions of computability and abstract computing devices. Other chapters consider the general notion of computability, with focus on the interaction bet

  12. Vascular endothelial growth factor promotes peripheral nerve regeneration after sciatic nerve transection in rat

    Institute of Scientific and Technical Information of China (English)

    Rahim Mohammadi; Sima Ahsan; Masoume Masoumi; Keyvan Amini

    2013-01-01

    Objective:To evaluate the local effect of vascular endothelial growth factor (VEGF) on transected sciatic nerve regeneration.Methods:Sixty male white Wistar rats were divided into four experimental groups randomly (n=15).In transected group the left sciatic nerve was transected and the stump was fixed to adjacent muscle.In treatment group the defect was bridged using a silicone graft filled with 10μL VEGF.In silicone group the graft was filled with phosphate-buffered saline.In sham-operated group the sciatic nerve was exposed and manipulated.Each group was subdivided into three subgroups with five animals in each and nerve fibers were studied 4,8 and 12 weeks after operation.Results:Behavioral test,functional study of sciatic nerve,gastrocnemius muscle mass and morphometric indices confirmed a faster recovery of regenerated axons in VEGF group than in silicone group (P<0.05).In immunohistochemical assessment,reactions to S-100 in VEGF group were more positive than that in silicone group.Conclusion:Local administration of VEGF will improve functional recovery and morphometric indices of sciatic nerve.

  13. Causes of Secondary Radial Nerve Palsy and Results of Treatment.

    Science.gov (United States)

    Reichert, Pawel; Wnukiewicz, Witold; Witkowski, Jarosław; Bocheńska, Aneta; Mizia, Sylwia; Gosk, Jerzy; Zimmer, Krzysztof

    2016-01-01

    BACKGROUND The aim of this study was to analyze the causes that lead to secondary damage of the radial nerve and to discuss the results of reconstructive treatment. MATERIAL AND METHODS The study group consisted of 33 patients treated for radial nerve palsy after humeral fractures. Patients were diagnosed based on clinical examinations, ultrasonography, electromyography, or nerve conduction velocity. During each operation, the location and type of nerve damage were analyzed. During the reconstructive treatment, neurolysis, direct neurorrhaphy, or reconstruction with a sural nerve graft was used. The outcomes were evaluated using the Medical Research Council (MRC) scales and the quick DASH score. RESULTS Secondary radial nerve palsy occurs after open reduction and internal fixation (ORIF) by plate, as well as by closed reduction and internal fixation (CRIF) by nail. In the case of ORIF, it most often occurs when the lateral approach is used, as in the case of CRIF with an insertion interlocking screws. The results of the surgical treatment were statistically significant and depended on the time between nerve injury and revision (reconstruction) surgery, type of damage to the radial nerve, surgery treatment, and type of fixation. Treatment results were not statistically significant, depending on the type of fracture or location of the nerve injury. CONCLUSIONS The potential risk of radial nerve neurotmesis justifies an operative intervention to treat neurological complications after a humeral fracture. Adequate surgical treatment in many of these cases allows for functional recovery of the radial nerve. PMID:26895570

  14. 化学法去细胞神经的制备及异体移植修复大鼠坐骨神经缺损的疗效%Fabrication of acellular nerve allograft through chemical extraction and efficacy with the use of the graft in repair of rat sciatic nerve defect

    Institute of Scientific and Technical Information of China (English)

    徐先立; 韩壮; 薛海鹏; 郭栋; 杨震

    2016-01-01

    Objective To evaluate regenerative nerve and functional recovery of target muscle in rats with sciatic nerve defect bridged by acellular nerve allograft made through chemical extraction.Methods Sciatic nerve of SD rats was processed in a volume fraction of 3% Triton X-lO0 solution and 40 g/L sodium deoxycholate solution.Morphology of myelin sheath,axons and basal lamina tubes of sciatic nerve segments was observed under the light microscopy before and after the chemical processing.Twenty-five Wistar rats were divided into acellular nerve allograft group (n =10),autograft group (n =10) and normal control group(n =5) according to the random number table.A 1 cm sciatic nerve defect was created in acellular nerve allograft group and autograft group,and was respectively bridged by acellular nerve allograft and autograft.Sciatic nerve function index (SFI) was measured every two weeks.Twelve weeks after surgery,nerve conduction velocity (NCV),recovery rate of compound muscle action potential (CMAP) and recovery rate of muscle force were measured in each group.Results Cellular components including myelin sheath and axons were removed thoroughly,but the basal lamina tubes were preserved completely.At postoperative 2,4,6,8,10 and 12 weeks,SFI in normal control group (-1.7±5.9,-0.3 ±2.5,0.8 ±4.1,-1.4±3.6,-2.5 ±5.7 and-2.1±3.2) was superior over autograft group (-94.3±3.7,-90.1±4.1,-63.7±7.8,-51.9±8.2,-48.8±8.6 and -44.3 ± 10.5) and acellular nerve allograft group (-97.1 ± 5.3,-91.2 ± 6.1,-70.6 ± 5.5,-60.4±6.2,-58.2 ±10.2 and-56.4 ±8.0) (P <0.01).At postoperative 6,8,10 and 12 weeks,SFI in autograft group were better than those in acellular nerve allograft group (P <0.05).NCV [(61.6 ± 8.1) m/s],recovery rate of CMAP[(98.7 ± 5.9) %] and recovery rate of muscle force [(101.8 ± 6.6) %] in normal control group were higher than those in acellular nerve allograft group [(22.3 ± 4.7) m/s,(40.3 ± 9.2) % and (43.8 ± 9.3) %] and those in autograft

  15. Cervical Radiculopathy (Pinched Nerve)

    Science.gov (United States)

    ... the seven small vertebrae that form the neck. Spinal nerve root. AAOS does not endorse any treatments, procedures, ... whether your symptoms are caused by pressure on spinal nerve roots and nerve damage or by another condition ...

  16. Nerve conduction velocity

    Science.gov (United States)

    Nerve conduction velocity (NCV) is a test to see how fast electrical signals move through a nerve. ... surface electrodes are placed on the skin over nerves at different spots. Each patch gives off a ...

  17. Optic Nerve Imaging

    Science.gov (United States)

    ... News About Us Donate In This Section Optic Nerve Imaging email Send this article to a friend ... measurements of nerve fiber damage (or loss). The Nerve Fiber Analyzer (GDx) uses laser light to measure ...

  18. Femoral nerve damage (image)

    Science.gov (United States)

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  19. Ulnar nerve damage (image)

    Science.gov (United States)

    The ulnar nerve originates from the brachial plexus and travels down arm. The nerve is commonly injured at the elbow because of elbow fracture or dislocation. The ulnar nerve is near the surface of the body where ...

  20. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    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

  1. Artificial Limbs

    Science.gov (United States)

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  2. Ciliary neurotrophic factor promotes motor reinnervation of the musculocutaneous nerve in an experimental model of end-to-side neurorrhaphy

    OpenAIRE

    Čelakovský Pavel; Stejskal Lubomír; Raška Otakar; Klusáková Ilona; Dubový Petr; Haninec Pavel

    2011-01-01

    Abstract Background It is difficult to repair nerve if proximal stump is unavailable or autogenous nerve grafts are insufficient for reconstructing extensive nerve damage. Therefore, alternative methods have been developed, including lateral anastomosis based on axons' ability to send out collateral sprouts into denervated nerve. The different capacity of a sensory or motor axon to send a sprout is controversial and may be controlled by cytokines and/or neurotrophic factors like ciliary neuro...

  3. Cross-face nerve transfer for established trigeminal branch II palsy.

    Science.gov (United States)

    Koshima, Isao; Narushima, Mitsunaga; Mihara, Makoto; Uchida, Gentaro; Nakagawa, Masahiro

    2009-12-01

    Reconstruction for trigeminal nerve II palsy is challenging. Cross-face nerve transfer from the contralateral trigeminal nerve facilitates this reconstruction. However, the microanatomy and techniques required for nerve sutures cause problems for many surgeons. Following the recent development of supramicrosurgical techniques appropriate for the microanatomy of peripheral nerves, a new method of intraoral "cross-face nerve transfer" was successfully used for repairing trigeminal nerve II palsy. Two cases of trigeminal nerve II palsy were repaired with contralateral trigeminal nerve transfer without any nerve graft. Affected upper labial sensory recovery was 1.65 to 2.44 (Semmes-Weinstein values) and 15 to 30 mm (moving 2-point discriminations) at 1 to 1 1/2 years after surgery. The advantages of this method are excellent nerve regeneration and the lack of donor site morbidity. It is a brief and simple operation in comparison to free nerve grafts. The disadvantage is a need for a supramicrosurgical technique, using a needle less than 80 microm wide. PMID:19934846

  4. Lateralization Technique and Inferior Alveolar Nerve Transposition

    Science.gov (United States)

    Sanches, Marco Antonio; Ramalho, Gabriel Cardoso; Manzi, Marcello Roberto

    2016-01-01

    Bone resorption of the posterior mandible can result in diminished bone edge and, therefore, the installation of implants in these regions becomes a challenge, especially in the presence of the mandibular canal and its contents, the inferior alveolar nerve. Several treatment alternatives are suggested: the use of short implants, guided bone regeneration, appositional bone grafting, distraction osteogenesis, inclined implants tangential to the mandibular canal, and the lateralization of the inferior alveolar nerve. The aim was to elucidate the success rate of implants in the lateralization technique and in inferior alveolar nerve transposition and to determine the most effective sensory test. We conclude that the success rate is linked to the possibility of installing implants with long bicortical anchor which favors primary stability and biomechanics. PMID:27433360

  5. Grafting and curing

    International Nuclear Information System (INIS)

    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

  6. Functional Reinnervation of the Canine Bladder after Spinal Root Transection and Immediate Somatic Nerve Transfer

    OpenAIRE

    RUGGIERI, MICHAEL R.; Braverman, Alan S.; D’ANDREA, LINDA; McCarthy, James; Barbe, Mary F.

    2008-01-01

    This study was performed to determine whether nerve transfer immediately after spinal root transection would lead to bladder reinnervation in a canine model. In one animal, the left T12 intercostal nerve was mobilized, cut and attached to the severed ends of sacral roots inducing bladder contraction using a graft from the T11 intercostal nerve. On the right side and bilaterally in two other dogs, coccygeal roots innervating tail musculature were cut and attached to the severed bladder sacral ...

  7. In vitro evaluation of cell-seeded chitosan films for peripheral nerve tissue engineering

    OpenAIRE

    Wrobel, Sandra; Serra, Sofia Cristina; Samy, S. M.; Sousa, Nuno; Heimann, Claudia; Barwig, Christina; Grothe, Claudia; Salgado, A. J.; Talini, Kirsten Haastert

    2014-01-01

    Natural biomaterials have attracted an increasing interest in the field of tissue-engineered nerve grafts, representing a possible alternative to autologous nerve transplantation. With the prospect of developing a novel entubulation strategy for transected nerves with cell-seeded chitosan films, we examined the biocompatibility of such films in vitro. Different types of rat Schwann cells (SCs)—immortalized, neonatal, and adult—as well as rat bone-marrow-derived mesenchymal stromal cells (BMSC...

  8. Surgical treatment of posterior interosseous nerve paralysis in a tennis player☆

    Science.gov (United States)

    Fujioka, Hiroyuki; Tsunemi, Kenjiro; Tsukamoto, Yoshitane; Oi, Takanori; Takagi, Yohei; Tanaka, Juichi; Yoshiya, Shinichi

    2014-01-01

    We report a rare case of posterior interosseous nerve (PIN) paralysis in a tennis player. The PIN, a 2 cm section from a bifurcation point of the radial nerve, presented increased stiffness in the surgical findings and treated with free sural nerve grafting after excision of the degenerative portion of the PIN. We speculate that PIN paralysis associated with hourglass-like constriction can be caused and exacerbated by repetitive forearm pronation and supination in playing tennis. PMID:25104896

  9. Butterfly cartilage graft versus fat graft myringoplasty

    Directory of Open Access Journals (Sweden)

    Sonika Kanotra

    2016-01-01

    Full Text Available Aim: The aim of the study was to compare the graft take up rates of two minimally invasive techniques of butterfly cartilage graft (BCG and fat graft myringoplasty (FGM. Materials and Methods: Two groups of 30 patients each with small dry central perforations of the tympanic membrane (T.M. were randomly subjected to either of the two techniques of myringoplasty. Statistical Analysis Used: The results were compared using the Chi-square test. A value of <0.05 was taken as statistically significant. Results: The graft take up rate was 93.3% with BCG and 83.3% with fat graft. Conclusions: The BCG scores over FGM in small perforations of the T.M.

  10. Bone grafts in dentistry

    OpenAIRE

    Prasanna Kumar; Belliappa Vinitha; Ghousia Fathima

    2013-01-01

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

  11. Bone grafts in dentistry

    Directory of Open Access Journals (Sweden)

    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.

  12. Anatomical peculiarities of sensory tracts of the wrist median nerve pedicled with nutrient vessels transferring to bridge wrist ulnar nerve defect

    Institute of Scientific and Technical Information of China (English)

    Sixin Ouyang; Zhenshan Peng; Jianguo Tan; Tianhong Peng; Jianzhong Xiao

    2006-01-01

    BACKGROUND: Translocation or transplantation of nerve stem has good effect;however, nervous function of donator is completely lost. If some nerve stem is damaged, sensory tracts are intercepted from the near nerve stem by nutrient vessels to regard as neural graft for transferring and bridging which may repair injured nerve and decrease neural functional loss of donator.OBJECTIVE: To observe anatomical peculiarities on sensory tracts of wrist median nerve pedicled with nutrient vessels transferring to bridge wrist ulnar nerve defect, and to investigate its feasibility.DESIGN: Duplicated and measured design.SETTING: Anatomy Department of Medical College affiliated to Nanhua University.MATERIALS: A total of 14 samples of upper limbs were selected from adult unnamed corpse and volunteers.METHODS: The experiment was completed at the Clinical Application Anatomy Laboratory of Medical College affiliated to Nanhua University from September to November 2005. Samples were perfused with red emulsion through artery to observe length, fibrous bands and blood supply of median nerve and ulnar nerve at wrist. Boundary of median nerve at wrist ranged from superficial site between flexor carpi radialis and palmaris longus to branch of common palmar digital nerves. Ulnar nerve at wrist ranged from branch of back of the hand to site of common palmar digital nerves. Proximal boundary of the two nerves was crossed from 1/8 to 2/8 region of forearm. Samples of upper limbs from 1 case were selected to simulate operation on sensory tracts of wrist median nerve pedicled with nutrient vessels transferring to bridge wrist ulnar nerve.MAIN OUTCOME MEASURES: Anatomical peculiarities on sensory tracts of wrist median nerve pedicled with nutrient vessels transferring to bridge wrist ulnar nerve defect.RESULTS: ① The length of wrist median nerves was 7.8 (7.5-8.1) cm. There were 19 to 27 nerve tracts in it and the majority belonged to sensory tracts on the ulnar side, in which non

  13. Peripheral nerve regeneration with conduits: use of vein tubes

    Directory of Open Access Journals (Sweden)

    Rodrigo Guerra Sabongi

    2015-01-01

    Full Text Available Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent loss of function. Tubolization techniques have been developed to bridge nerve gaps and have been extensively studied in numerous experimental and clinical trials. The use of a conduit intends to act as a vehicle for moderation and modulation of the cellular and molecular ambience for nerve regeneration. Among several conduits, vein tubes were validated for clinical application with improving outcomes over the years. This article aims to address the investigation and treatment of segmental nerve injury and draw the current panorama on the use of vein tubes as an autogenous nerve conduit.

  14. Growth Factor and Laminin Effect with Muscular Fiber Sheath on Repairing of the Sciatica Nerve

    Directory of Open Access Journals (Sweden)

    S Torabi

    2014-01-01

    Background & aim: Peripheral nerve injuries which can lead to a physical disability. If the defect is very low, direct suture without tension on both ends of the cut nerve regeneration is considered as a standard procedure. Otherwise, to reconstruct the axons, the gap must be filled by graft material in order to the guidance. Due to the similarity of the matrix tubular skeletal muscle and nerve muscles graft was used to repair in this study. Methods: In the present experimental study, 42 female Wistar rats were divided into three groups and underwent surgery. In the first group a narrow strip of muscle was prepared by freezing – thawing, and later sutured between the distal and proximal sciatic nerve. In the second group, the gap caused by muscle graft was regenerated and the nerve growth factor and laminin was injected into the graft. In the control group, the two ends of the cut nerve were hidden beneath the adjacent muscles. Next, a group of rats with sciatic functional index was investigated for the behavioral. On the other group were examined for histological studies after two months. Results: Sciatic functional index and Mean counts of myelinated fibers in two graft groups compared with the control group was significant p<0.05. Statistical analysis was performed using ANOVA test. Conclusion: co-axially aligned muscle grafts were an appropriate alternative substitute for repairing. It seems that the nerve growth factor and laminin have a positive role in axonal regeneration and functional recovery acceleration. Key words: Sciatic Functional Index, muscle graft, NGF, Laminin

  15. Nerve autografts and tissue-engineered materials for the repair of peripheral nerve injuries: a 5-year bibliometric analysis

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2015-01-01

    Full Text Available With advances in biomedical methods, tissue-engineered materials have developed rapidly as an alternative to nerve autografts for the repair of peripheral nerve injuries. However, the materials selected for use in the repair of peripheral nerve injuries, in particular multiple injuries and large-gap defects, must be chosen carefully. Various methods and materials for protecting the healthy tissue and repairing peripheral nerve injuries have been described, and each method or material has advantages and disadvantages. Recently, a large amount of research has been focused on tissue-engineered materials for the repair of peripheral nerve injuries. Using the keywords "pe-ripheral nerve injury", "autotransplant", "nerve graft", and "biomaterial", we retrieved publications using tissue-engineered materials for the repair of peripheral nerve injuries appearing in the Web of Science from 2010 to 2014. The country with the most total publications was the USA. The institutions that were the most productive in this field include Hannover Medical School (Germany, Washington University (USA, and Nantong University (China. The total number of publications using tissue-engineered materials for the repair of peripheral nerve injuries grad-ually increased over time, as did the number of Chinese publications, suggesting that China has made many scientific contributions to this field of research.

  16. Artificial blood

    Directory of Open Access Journals (Sweden)

    Sarkar Suman

    2008-01-01

    Full Text Available Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  17. Engineering a multimodal nerve conduit for repair of injured peripheral nerve

    Science.gov (United States)

    Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

    2013-02-01

    Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate

  18. Diabetes and nerve damage

    Science.gov (United States)

    Nerve damage that occurs in people with diabetes is called diabetic neuropathy. This condition is a complicaiton ... In people with diabetes, the body's nerves can be damaged by ... sugar level . This condition is more likely when the blood sugar ...

  19. Degenerative Nerve Diseases

    Science.gov (United States)

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many ... viruses. Sometimes the cause is not known. Degenerative nerve diseases include Alzheimer's disease Amyotrophic lateral sclerosis Friedreich's ...

  20. Radial nerve dysfunction (image)

    Science.gov (United States)

    The radial nerve travels down the arm and supplies movement to the triceps muscle at the back of the upper arm. ... the wrist and hand. The usual causes of nerve dysfunction are direct trauma, prolonged pressure on the ...

  1. Vein conduit associated with microsurgical suture for complete collateral digital nerve severance.

    Science.gov (United States)

    Alligand-Perrin, P; Rabarin, F; Jeudy, J; Césari, B; Saint-Cast, Y; Fouque, P-A; Raimbeau, G

    2011-06-01

    The aim of this study is to present the long term results of a series of 53 vein conduit grafts as first line therapy to repair complete severance of one or more collateral digital nerves. The surgical technique included an epi-perineural suture of the nerve under minimal tension, associated with a vein graft harvested from the back of the hand to cover the nerve. None of the patients presented with a neuroma, spontaneous pain or had stopped using the injured finger. Sensibility results were good or very good in 67% of cases. The scar at the donor site was very light or invisible. A total of 96% of patients were satisfied or very satisfied. This simple technique, by protecting the injured nerve, results in a rate of sensory nerve recovery that is comparable or better than that of other series in the literature, without neuroma and with minimal scarring at the donor site. PMID:21531189

  2. Sensory nerves and pancreatitis

    OpenAIRE

    Li, Qingfu; PENG, JIE

    2014-01-01

    Sensory nerves are a kind of nerve that conduct afferent impulses from the periphery receptors to the central nervous system (CNS) and are able to release neuromediators from the activated peripheral endings. Sensory nerves are particularly important for microcirculatory response, and stimulation of pancreatic sensory nerves releases a variety of neuropeptides such as substance P (SP), calcitonin gene-related peptide (CGRP), etc., leading to neurogenic inflammation characterized as the local ...

  3. The Furcal Nerve Revisited

    OpenAIRE

    Harshavardhana, Nanjundappa S.; Harshad V. Dabke

    2014-01-01

    Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked) is an independent nerve with its own ventral and dorsal branches (rootlets) and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to t...

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

    Directory of Open Access Journals (Sweden)

    Sven Duda

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  6. The Physics of Nerves

    CERN Document Server

    Heimburg, Thomas

    2010-01-01

    The accepted model for nerve pulse propagation in biological membranes seems insufficient. It is restricted to dissipative electrical phenomena and considers nerve pulses exclusively as a microscopic phenomenon. A simple thermodynamic model that is based on the macroscopic properties of membranes allows explaining more features of nerve pulse propagation including the phenomenon of anesthesia that has so far remained unexplained.

  7. Intraparotid facial nerve schwannoma.

    OpenAIRE

    Shah H; Kantharia C; Shenoy A

    1997-01-01

    Intraparotid facial nerve schwannoma are uncommon. Preoperative diagnosis of parotid tumour as schwannoma is difficult when facial nerve function is normal. A rare case of solitary schwannoma involving the upper branch of the facial nerve is described and the literature on the subject is reviewed.

  8. Laryngeal nerve damage

    Science.gov (United States)

    Laryngeal nerve damage is injury to one or both of the nerves that are attached to the voice box. ... Injury to the laryngeal nerves is uncommon. When it does occur, it can be from: A complication of neck or chest surgery (especially thyroid, lung, ...

  9. Optic Nerve Pit

    Science.gov (United States)

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Pit What is optic nerve pit? An optic nerve pit is a ... may be seen in both eyes. How is optic pit diagnosed? If the pit is not affecting ...

  10. Efficacy of nanofibrous conduits in repair of long-segment sciatic nerve defects*

    Institute of Scientific and Technical Information of China (English)

    Esmaeil Biazar; Saeed Heidari Keshel; Majid Pouya

    2013-01-01

    Our previous studies have histomorphological y confirmed that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) conduit can be used to repair 30-mm-long sciatic nerve defects. However, the repair effects on rat behaviors remain poorly understood. In this study, we used nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) conduit and autologous sciatic nerve to bridge 30-mm-long rat sciatic nerve gaps. Within 4 months after surgery, rat sciatic nerve functional re-covery was evaluated per month by behavioral analyses, including toe out angle, toe spread anal-ysis, walking track analysis, extensor postural thrust, swimming test, open-field analysis and noci-ceptive function. Results showed that rat sciatic nerve functional recovery was similar after nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) conduit and autologous nerve grafting. These findings suggest that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) conduit is suitable in use for repair of long-segment sciatic nerve defects.

  11. Artificial intelligence

    CERN Document Server

    Ennals, J R

    1987-01-01

    Artificial Intelligence: State of the Art Report is a two-part report consisting of the invited papers and the analysis. The editor first gives an introduction to the invited papers before presenting each paper and the analysis, and then concludes with the list of references related to the study. The invited papers explore the various aspects of artificial intelligence. The analysis part assesses the major advances in artificial intelligence and provides a balanced analysis of the state of the art in this field. The Bibliography compiles the most important published material on the subject of

  12. Artificial urushi.

    Science.gov (United States)

    Kobayashi, S; Uyama, H; Ikeda, R

    2001-11-19

    A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity. PMID:11763444

  13. Cutaneous sensory nerve as a substitute for auditory nerve in solving deaf-mutes’ hearing problem: an innovation in multi-channel-array skin-hearing technology

    OpenAIRE

    Li, Jianwen; Li, Yan; Zhang, Ming; Ma, Weifang; Ma, Xuezong

    2014-01-01

    The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice signals at different...

  14. Study on biotribological properties of UHMWPE grafted with MPDSAH

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yaling; Xiong, Dangsheng, E-mail: xiongds@163.com; Shao, Silong

    2013-04-01

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

  15. Study on biotribological properties of UHMWPE grafted with MPDSAH

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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)

  17. Artificial Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block...

  18. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  19. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch;

    2005-01-01

    The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect the...... optic nerve oxygen tension. If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. A disturbance in oxidative metabolism in the cytochromes of the optic nerve can be seen at...... similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...

  20. [Ganglia of peripheral nerves].

    Science.gov (United States)

    Tatagiba, M; Penkert, G; Samii, M

    1993-01-01

    The authors present two different types of ganglion affecting the peripheral nerves: extraneural and intraneural ganglion. Compression of peripheral nerves by articular ganglions is well known. The surgical management involves the complete removal of the lesion with preservation of most nerve fascicles. Intraneural ganglion is an uncommon lesion which affects the nerve diffusely. The nerve fascicles are usually intimately involved between the cysts, making complete removal of all cysts impossible. There is no agreement about the best surgical management to be applied in these cases. Two possibilities are available: opening of the epineural sheath lengthwise and pressing out the lesion; or resection of the affected part of the nerve and performing a nerve reconstruction. While in case of extraneural ganglion the postoperative clinical evolution is very favourable, only long follow up studies will reveal in case of intraneural ganglion the best surgical approach. PMID:8128785

  1. Assessment of nerve morphology in nerve activation during electrical stimulation

    Science.gov (United States)

    Gomez-Tames, Jose; Yu, Wenwei

    2013-10-01

    The distance between nerve and stimulation electrode is fundamental for nerve activation in Transcutaneous Electrical Stimulation (TES). However, it is not clear the need to have an approximate representation of the morphology of peripheral nerves in simulation models and its influence in the nerve activation. In this work, depth and curvature of a nerve are investigated around the middle thigh. As preliminary result, the curvature of the nerve helps to reduce the simulation amplitude necessary for nerve activation from far field stimulation.

  2. 小鼠神经缺损管式修复后长时程功能恢复与再生评价%Long-term evaluation of functional recovery and nerve regeneration following tubulation repair of nerve defects in mice

    Institute of Scientific and Technical Information of China (English)

    糜大国; 张燕平; 顾天文; 赵亚红; 胡文

    2014-01-01

    Objective This study is to identify long-term functional recovery and maturity of regenerated nerve fibers after repairing mouse nerve defects with chitosan/polylactide-co-polyglycolide artificial nerve grafts ( CPANGs ) . Methods Mouse sciatic nerve defects, 2mm in length, were bridged by CPANGs (n=6), with nerve autograft (n=6) and nerve defect (n=6) as controls.Plantar test, electrophysiological examination and laser Doppler perfusion imaging following nerve crush were carried out at 1 year after repair to assess nerve function recovery , while muscle wet weight ratio, histological assessment and transmission electron microscopy were performed to evaluate nerve re -innervation and maturity of regenerated nerve fibers .Results When compared to the autograft group , the CPANG group did not show statistically significant difference in functional recovery in terms of paw withdrawal latency , neurogenic vasodilatation , amplitude and latency of compound muscle action potentials ( CMAPs ) , wet weight ratio of gastrocnemius and tibialis cranialis muscles , number of myelinated nerve fibers and density of unmyelinated axons .However , both these two repair groups exhibited significantly longer CMAPs latency , thinner myelin sheath and a lag-behind shift of diameter distribution of myelinated axons as compared to the normal control .Conclusion At 1 year after the mouse sciatic nerve defect was repaired by CPANGs , sensory and autonomic nerve function , number of regenerated axons and muscle re-innervation degree were recovered to the same extent as nerve autografting , but the regenerated nerve fibers were in a state of immaturity .%目的:了解壳聚糖/聚乳酸-乙醇酸共聚体( PLGA)人工神经移植物修复小鼠神经缺损后神经功能长时程恢复水平与再生神经成熟度。方法采用人工神经移植物桥接修复小鼠坐骨神经缺损(n=6),以自体神经修复(n=6)和缺损组(n=6)为对照,术后1年采用

  3. Imaging the trigeminal nerve

    International Nuclear Information System (INIS)

    Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

  4. Imaging the trigeminal nerve

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Radiology Department, Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Rua Prof. Lima Basto, 1093, Lisboa (Portugal)], E-mail: borgalexandra@gmail.com; Casselman, Jan [Department of Radiology, A. Z. St Jan Brugge and A. Z. St Augustinus Antwerpen Hospitals (Belgium)

    2010-05-15

    Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

  5. Chronic Posttraumatic Dislocation of Radial Head With Ulnar Nerve Entrapment in a Child: A Case Report and Literature Review.

    Science.gov (United States)

    Cai, Jiangyu; Wang, Wei; Yu, Shiyang; Yan, Hede; Zhan, Yulin; Fan, Cunyi

    2016-06-01

    We present an unusual case of chronic posttraumatic anteromedial dislocation of radial head with direct ulnar nerve entrapment in a child. Ulnar nerve decompression, open reduction of the radial head, and annular ligament reconstruction using a palmaris longus tendon graft were performed, and a satisfactory functional outcome was achieved at the 15-month follow-up. Through a review of literature, we conclude that early diagnosis and management for radial head dislocation are recommended to avoid nerve symptoms. Besides, open reduction and annular ligament reconstruction with a palmaris longus tendon graft would be an alternative surgery during chronic phase. PMID:27171922

  6. A novel electrospun nerve conduit enhanced by carbon nanotubes for peripheral nerve regeneration

    Science.gov (United States)

    Yu, Wenwen; Jiang, Xinquan; Cai, Ming; Zhao, Wen; Ye, Dongxia; Zhou, Yong; Zhu, Chao; Zhang, Xiuli; Lu, Xiaofeng; Zhang, Zhiyuan

    2014-04-01

    For artificial nerve conduits, great improvements have been achieved in mimicking the structures and components of autologous nerves. However, there are still some problems in conduit construction, especially in terms of mechanical properties, biomimetic surface tomography, electrical conductivity and sustained release of neurotrophic factors or cells. In this study, we designed and fabricated a novel electrospun nerve conduit enhanced by multi-walled carbon nanotubes (MWNTs) on the basis of a collagen/poly(ɛ-caprolactone) (collagen/PCL) fibrous scaffold. Our aim was to provide further knowledge about the mechanical effects and efficacy of MWNTs on nerve conduits as well as the biocompatibility and toxicology of MWNTs when applied in vivo. The results showed that as one component, carboxyl MWNTs could greatly alter the composite scaffold’s hydrophilicity, mechanical properties and degradability. The electrospun fibers enhanced by MWNTs could support Schwann cell adhesion and elongation as a substrate in vitro. In vivo animal studies demonstrated that the MWNT-enhanced collagen/PCL conduit could effectively promote nerve regeneration of sciatic nerve defect in rats and prevent muscle atrophy without invoking body rejection or serious chronic inflammation. All of these results showed that this MWNT-enhanced scaffold possesses good biocompatibility and MWNTs might be excellent candidates as engineered nanocarriers for further neurotrophic factor delivery research.

  7. A novel electrospun nerve conduit enhanced by carbon nanotubes for peripheral nerve regeneration

    International Nuclear Information System (INIS)

    For artificial nerve conduits, great improvements have been achieved in mimicking the structures and components of autologous nerves. However, there are still some problems in conduit construction, especially in terms of mechanical properties, biomimetic surface tomography, electrical conductivity and sustained release of neurotrophic factors or cells. In this study, we designed and fabricated a novel electrospun nerve conduit enhanced by multi-walled carbon nanotubes (MWNTs) on the basis of a collagen/poly(ε-caprolactone) (collagen/PCL) fibrous scaffold. Our aim was to provide further knowledge about the mechanical effects and efficacy of MWNTs on nerve conduits as well as the biocompatibility and toxicology of MWNTs when applied in vivo. The results showed that as one component, carboxyl MWNTs could greatly alter the composite scaffold’s hydrophilicity, mechanical properties and degradability. The electrospun fibers enhanced by MWNTs could support Schwann cell adhesion and elongation as a substrate in vitro. In vivo animal studies demonstrated that the MWNT-enhanced collagen/PCL conduit could effectively promote nerve regeneration of sciatic nerve defect in rats and prevent muscle atrophy without invoking body rejection or serious chronic inflammation. All of these results showed that this MWNT-enhanced scaffold possesses good biocompatibility and MWNTs might be excellent candidates as engineered nanocarriers for further neurotrophic factor delivery research. (paper)

  8. Artificial noses.

    Science.gov (United States)

    Stitzel, Shannon E; Aernecke, Matthew J; Walt, David R

    2011-08-15

    The mammalian olfactory system is able to detect many more odorants than the number of receptors it has by utilizing cross-reactive odorant receptors that generate unique response patterns for each odorant. Mimicking the mammalian system, artificial noses combine cross-reactive sensor arrays with pattern recognition algorithms to create robust odor-discrimination systems. The first artificial nose reported in 1982 utilized a tin-oxide sensor array. Since then, however, a wide range of sensor technologies have been developed and commercialized. This review highlights the most commonly employed sensor types in artificial noses: electrical, gravimetric, and optical sensors. The applications of nose systems are also reviewed, covering areas such as food and beverage quality control, chemical warfare agent detection, and medical diagnostics. A brief discussion of future trends for the technology is also provided. PMID:21417721

  9. Effects of different nerve autografts on greater auricular nerve deficit in rabbits

    Institute of Scientific and Technical Information of China (English)

    Shaozong Chen

    2007-01-01

    BACKGROUND: Autograft is commonly used to repair nerve deficit. Usually, the choice of donor nerves is based on their similarities in form and structures to the injured nerves. For the reason, the cutaneous antebrachii lateralis nerve is currently considered the most suited for digital nerve repair. OBJECTIVE: To compare early nerve regeneration after transplantation of three different autografts: the greater auricular nerve (CAN), the saphenous nerve (SN) and the lateral femoral cutaneous nerve (LFCN). DESIGN: Observational contrast study. SETTING: Department of Plastic Surgery and Burns, Tangdu Hospital, Fourth Military Medical University of Chinese PLA.MATERIALS: A total of 42 New Zealand rabbits, of both genders, 12 - 14 months old and weighing 2.0 -2.5 kg, were used in this study. In addition, Moller-spetra 900 operating microscope (Germany), Olympus BX 51 microscope, DP 70 image collecting System (Japan), BL-420E+ Biologic function testing System (China), JEM-100 electron microscope (Japan), Reichet-JunG820 Cryostat (Swiss), and Libror-AEG-120 precision analytical Balance (Japan) were also used in this study.METHODS: The experiment was carried out in the Department of Plastic Surgery and Burns, Tangdu Hospital, Fourth Military Medical University of Chinese PLA from April to November 2005. After anaesthesia, the GAN were dissected bilaterally and a 1.2 cm deficit was made in each nerve. The animals were randomly divided into three groups, including GAN group, SN group and LFCN group with 14 in each group. ①Nerve pinch test: At 1,2, and 4 weeks after operation, three animals in each group were tested. The nerve grafts, along with the proximal and distal GAN segments were exposed and pinched with microsurgical forceps in distal-proximal orientations. The distance between the proximal anastomosis site and the most distal point, where the pinch evoked an ear contraction response, was measured as distance of nerve regeneration. ②Computer image analysis: At 4

  10. Sciatic nerve injection injury.

    Science.gov (United States)

    Jung Kim, Hyun; Hyun Park, Sang

    2014-06-11

    Nerve injury is a common complication following intramuscular injection and the sciatic nerve is the most frequently affected nerve, especially in children, the elderly and underweight patients. The neurological presentation may range from minor transient pain to severe sensory disturbance and motor loss with poor recovery. Management of nerve injection injury includes drug treatment of pain, physiotherapy, use of assistive devices and surgical exploration. Early recognition of nerve injection injury and appropriate management are crucial in order to reduce neurological deficit and to maximize recovery. Sciatic nerve injection injury is a preventable event. Total avoidance of intramuscular injection is recommended if other administration routes can be used. If the injection has to be administered into the gluteal muscle, the ventrogluteal region (gluteal triangle) has a more favourable safety profile than the dorsogluteal region (the upper outer quadrant of the buttock). PMID:24920643

  11. The furcal nerve revisited

    Directory of Open Access Journals (Sweden)

    Nanjundappa S. Harshavardhana

    2014-10-01

    Full Text Available Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked is an independent nerve with its own ventral and dorsal branches (rootlets and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to the lumbosacral trunk. It is most commonly found at L4 level and is the most common cause of atypical presentation of radiculopathy/sciatica. Very little is published about the furcal nerve and many are unaware of its existence. This article summarizes all the existing evidence about furcal nerve in English literature in an attempt to create awareness and offer insight about this unique entity to fellow colleagues/ professionals involved in spine care.

  12. The Furcal Nerve Revisited

    Science.gov (United States)

    Dabke, Harshad V.

    2014-01-01

    Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked) is an independent nerve with its own ventral and dorsal branches (rootlets) and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to the lumbosacral trunk. It is most commonly found at L4 level and is the most common cause of atypical presentation of radiculopathy/sciatica. Very little is published about the furcal nerve and many are unaware of its existence. This article summarizes all the existing evidence about furcal nerve in English literature in an attempt to create awareness and offer insight about this unique entity to fellow colleagues/professionals involved in spine care. PMID:25317309

  13. Facial nerve neuromas: MR imaging. Report of four cases

    Energy Technology Data Exchange (ETDEWEB)

    Martin, N. (G.H. Pitie-Salpetriere, 75 - Paris (France). Dept. of Neuroradiology); Sterkers, O. (Hospital Beaujon, Clichy (France). Dept. of Otorhinolaryngology); Mompoint, D.; Nahum, H. (Hopital Beaujon, Clichy (France). Dept. of Radiology)

    1992-02-01

    Four cases of facial nerve neuroma were evaluated by computed tomographic (CT) scan and magnetic resonance imaging (MRI). The extension of the tumor in the petrous bone or the parotid gland was well defined by MRI in all cases. CT scan was useful to demonstrate bone erosions and the relation of the tumor to inner ear structures. In cases of progressive facial palsy, CT and MRI should be combined to detect a facial neuroma and to plan the surgical approach for tumor removal and nerve grafting. (orig.).

  14. Artificial intelligence

    International Nuclear Information System (INIS)

    A vivid example of the growing need for frontier physics experiments to make use of frontier technology is in the field of artificial intelligence and related themes. This was reflected in the second international workshop on 'Software Engineering, Artificial Intelligence and Expert Systems in High Energy and Nuclear Physics' which took place from 13-18 January at France Telecom's Agelonde site at La Londe des Maures, Provence. It was the second in a series, the first having been held at Lyon in 1990

  15. Artificial Intelligence

    CERN Document Server

    Warwick, Kevin

    2011-01-01

    if AI is outside your field, or you know something of the subject and would like to know more then Artificial Intelligence: The Basics is a brilliant primer.' - Nick Smith, Engineering and Technology Magazine November 2011 Artificial Intelligence: The Basics is a concise and cutting-edge introduction to the fast moving world of AI. The author Kevin Warwick, a pioneer in the field, examines issues of what it means to be man or machine and looks at advances in robotics which have blurred the boundaries. Topics covered include: how intelligence can be defined whether machines can 'think' sensory

  16. Injectable systems and implantable conduits for peripheral nerve repair

    International Nuclear Information System (INIS)

    Acute sensory problems following peripheral nerve injury include pain and loss of sensation. Approximately 360 000 people in the United States suffer from upper extremity paralytic syndromes every year. Restoration of sufficient functional recovery after long-gap peripheral nerve damage remains a clinical challenge. Potential nerve repair therapies have increased in the past decade as the field of tissue engineering expands. The following review describes the use of biomaterials in nerve tissue engineering. Namely, the use of both synthetic and natural biomaterials, including non-degradable and degradable nerve grafts, is addressed. The enhancement of axonal regeneration can be achieved by further modification of the nerve guides. These approaches include injectable hydrogel fillers, controlled drug delivery systems, and cell incorporation. Hydrogels are a class of liquid–gel biomaterials with high water content. Injectable and gelling hydrogels can serve as growth factor delivery vehicles and cell carriers for tissue engineering applications. While natural hydrogels and polymers are suitable for short gap nerve repair, the use of polymers for relatively long gaps remains a clinical challenge. (paper)

  17. Spinal accessory nerve neurilemmoma

    International Nuclear Information System (INIS)

    A neurilemmoma of the spinal accessory nerve extending from the lower brain stem to the high cervical region, without typical jugular foramen syndome is presented. Preoperative diagnosis is difficult but should be considered in the differential diagnosis of a high cervical intradural extramedullary lesion in patients with lower cranial nerve(s) dysfunction. The value of intrathecal and intravenous contrast enhancement computed tomography (CT) myelogram is emphasized. 13 refs.; 3 figs

  18. Artificial sweeteners

    DEFF Research Database (Denmark)

    Raben, Anne Birgitte; Richelsen, Bjørn

    2012-01-01

    Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie-containin...

  19. Artificial photosynthesis

    OpenAIRE

    Andrew C. Benniston; Anthony Harriman

    2008-01-01

    We raise here a series of critical issues regarding artificial photosynthesis with the intention of increasing awareness about what needs to be done to bring about a working prototype. Factors under consideration include energy and electron transfers, coupled redox reactions, repair mechanisms, and integrated photosystems.

  20. Mechanics of Cellular Adhesion to Artificial Artery Templates

    OpenAIRE

    Knöner, Gregor; Rolfe, Barbara E.; Campbell, Julie H.; Parkin, Simon J.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2006-01-01

    We are using polymer templates to grow artificial artery grafts in vivo for the replacement of diseased blood vessels. We have previously shown that adhesion of macrophages to the template starts the graft formation. We present a study of the mechanics of macrophage adhesion to these templates on a single cell and single bond level with optical tweezers. For whole cells, in vitro cell adhesion densities decreased significantly from polymer templates polyethylene to silicone to Tygon (167, 135...

  1. Bone Graft Alternatives

    Science.gov (United States)

    ... cadavers. The types of allograft bone used for spine surgery include fresh frozen and lyophilized (freeze dried). The ... the most common uses of bone grafts in spine surgery is during spinal fusion. The use of autogenous ...

  2. Proximal Tibial Bone Graft

    Science.gov (United States)

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

  3. Epidermal skin grafting.

    Science.gov (United States)

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

    2016-09-01

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

  4. Efficacy of low level laser therapy on neurosensory recovery after injury to the inferior alveolar nerve

    OpenAIRE

    Gorur Ilker; Orhan Kaan; Ozen Tuncer; Ozturk Adnan

    2006-01-01

    Abstract Background The most severe complication after the removal of mandibular third molars is injury to the inferior alveolar nerve or the lingual nerve. These complications are rather uncommon (0.4% to 8.4%) and most of them are transient. However, some of them persist for longer than 6 months, which can leave various degrees of long-term permanent disability. While several methods such as pharmacologic therapy, microneurosurgery, autogenous and alloplastic grafting can be used for the tr...

  5. Three-dimensional Reconstruction of the Microstructure of Human Acellular Nerve Allograft.

    Science.gov (United States)

    Zhu, Shuang; Zhu, Qingtang; Liu, Xiaolin; Yang, Weihong; Jian, Yutao; Zhou, Xiang; He, Bo; Gu, Liqiang; Yan, Liwei; Lin, Tao; Xiang, Jianping; Qi, Jian

    2016-01-01

    The exact inner 3D microstructure of the human peripheral nerve has been a mystery for decades. Therefore, it has been difficult to solve several problems regarding peripheral nerve injury and repair. We used high-resolution X-ray computed microtomography (microCT) to scan a freeze-dried human acellular nerve allograft (hANA). The microCT images were then used to reconstruct a 3D digital model, which was used to print a 3D resin model of the nerve graft. The 3D digital model of the hANA allowed visualization of all planes. The magnified 3D resin model clearly showed the nerve bundles and basement membrane tubes of the hANA. Scanning electron microscopy (SEM) was used to analyse the microstructure of the hANA. Compared to the SEM images, the microCT image clearly demonstrated the microstructure of the hANA cross section at a resolution of up to 1.2 μm. The 3D digital model of the hANA facilitates a clear and easy understanding of peripheral nerve microstructure. Furthermore, the enlarged 3D resin model duplicates the unique inner structure of each individual hANA. This is a crucial step towards achieving 3D printing of a hANA or nerve that can be used as a nerve graft. PMID:27476584

  6. [Zaidemberg's vascularized radial graft].

    Science.gov (United States)

    Saint-Cast, Y

    2010-12-01

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

  7. Intraoperative vagal nerve monitoring.

    Science.gov (United States)

    Leonetti, J P; Jellish, W S; Warf, P; Hudson, E

    1996-08-01

    A variety of benign and malignant neoplasms occur in the superior cervical neck, parapharyngeal space or the infratemporal fossa. The surgical resection of these lesions may result in postoperative iatrogenic injury to the vagus nerve with associated dysfunctional swallowing and airway protection. Anatomic and functional preservation of this critical cranial nerve will contribute to a favorable surgical outcome. Fourteen patients with tumors of the cervical neck or adjacent skull base underwent intraoperative vagal nerve monitoring in an attempt to preserve neural integrity following tumor removal. Of the 11 patients with anatomically preserved vagal nerves in this group, seven patients had normal vocal cord mobility following surgery and all 11 patients demonstrated normal vocal cord movement by six months. In an earlier series of 23 patients with tumors in the same region who underwent tumor resection without vagal nerve monitoring, 18 patients had anatomically preserved vagal nerves. Within this group, five patients had normal vocal cord movement at one month and 13 patients demonstrated normal vocal cord movement at six months. This paper will outline a technique for intraoperative vagal nerve monitoring utilizing transcricothyroid membrane placement of bipolar hook-wire electrodes in the vocalis muscle. Our results with the surgical treatment of cervical neck and lateral skull base tumors for patients with unmonitored and monitored vagal nerves will be outlined. PMID:8828272

  8. Analysis of cartilage-polydioxanone foil composite grafts.

    Science.gov (United States)

    Kim, James H; Wong, Brian

    2013-12-01

    This study presents an analytical investigation into the mechanical behavior of a cartilage-polydioxanone (PDS) plate composite grafts. Numerical methods are used to provide a first-order, numerical model of the flexural stiffness of a cartilage-PDS graft. Flexural stiffness is a measure of resistance to bending and is inversely related to the amount of deformation a structure may experience when subjected to bending forces. The cartilage-PDS graft was modeled as a single composite beam. Using Bernoulli-Euler beam theory, a closed form equation for the theoretical flexural stiffness of the composite graft was developed. A parametric analysis was performed to see how the flexural properties of the composite model changed with varying thicknesses of PDS foil. The stiffness of the cartilage-PDS composite using 0.15-mm-thick PDS was four times higher than cartilage alone. The composite with a 0.5-mm-thick PDS graft was only 1.7 times stiffer than the composite with the 0.15-mm-thick PDS graft. Although a thicker graft material will yield higher flexural stiffness for the composite, the relationship between composite stiffness and PDS thickness is nonlinear. After a critical point, increments in graft thickness produce gradually smaller improvements in flexural stiffness. The small increase in stiffness when using the thicker PDS foils versus the 0.15 mm PDS foil may not be worth the potential complications (prolonged foreign body reaction, reduction in nutrient diffusion to cartilage) of using thicker artificial grafts. PMID:24327249

  9. Preoperative transcutaneous electrical nerve stimulation for localizing superficial nerve paths.

    Science.gov (United States)

    Natori, Yuhei; Yoshizawa, Hidekazu; Mizuno, Hiroshi; Hayashi, Ayato

    2015-12-01

    During surgery, peripheral nerves are often seen to follow unpredictable paths because of previous surgeries and/or compression caused by a tumor. Iatrogenic nerve injury is a serious complication that must be avoided, and preoperative evaluation of nerve paths is important for preventing it. In this study, transcutaneous electrical nerve stimulation (TENS) was used for an in-depth analysis of peripheral nerve paths. This study included 27 patients who underwent the TENS procedure to evaluate the peripheral nerve path (17 males and 10 females; mean age: 59.9 years, range: 18-83 years) of each patient preoperatively. An electrode pen coupled to an electrical nerve stimulator was used for superficial nerve mapping. The TENS procedure was performed on patients' major peripheral nerves that passed close to the surgical field of tumor resection or trauma surgery, and intraoperative damage to those nerves was apprehensive. The paths of the target nerve were detected in most patients preoperatively. The nerve paths of 26 patients were precisely under the markings drawn preoperatively. The nerve path of one patient substantially differed from the preoperative markings with numbness at the surgical region. During surgery, the nerve paths could be accurately mapped preoperatively using the TENS procedure as confirmed by direct visualization of the nerve. This stimulation device is easy to use and offers highly accurate mapping of nerves for surgical planning without major complications. The authors conclude that TENS is a useful tool for noninvasive nerve localization and makes tumor resection a safe and smooth procedure. PMID:26420473

  10. Artificial Intelligence.

    Science.gov (United States)

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve. PMID:26957450

  11. Artificial intelligence

    OpenAIRE

    Duda, Antonín

    2009-01-01

    Abstract : Issue of this work is to acquaint the reader with the history of artificial inteligence, esspecialy branch of chess computing. Main attention is given to progress from fifties to the present. The work also deals with fighting chess programs against each other, and against human opponents. The greatest attention is focused on 1997 and duel Garry Kasparov against chess program Deep Blue. The work is divided into chapters according to chronological order.

  12. Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2015-01-01

    regeneration was found with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel grafts than with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.

  13. Porous hydroxyapatite for artificial bone applications

    OpenAIRE

    I. Sopyan et al

    2007-01-01

    Hydroxyapatite (HA) has been used clinically for many years. It has good biocompatibility in bone contact as its chemical composition is similar to that of bone material. Porous HA ceramics have found enormous use in biomedical applications including bone tissue regeneration, cell proliferation, and drug delivery. In bone tissue engineering it has been applied as filling material for bone defects and augmentation, artificial bone graft material, and prosthesis revision surgery. Its high surfa...

  14. Morphological features of allogenic nerve segment in rats after subcutaneous embedment

    Institute of Scientific and Technical Information of China (English)

    Mingtang Gao; Dianming Jiang

    2006-01-01

    BACKGROUND: Some studies demonstrate that allogenic peripheral nerve segment embedded subcutaneously significantly reduce the infiltration of lymphocyte and decrease immunological reaction.OBJECTIVE: To observe the gross shape, optical and electron microscope results of allogenic nerve segment in rats 2 weeks after subcutaneous embedment, and compare with subcutaneous emdedment of autologous nerve segment.DESIGN: A randomized and controlled experiment.SETTING: Department of Orthopaedics of Fifth People's Hospital of Zhengzhou; Department of Orthopaedics,First Hospital Affiliated to Chongqing Medical University MATERIALS: Totally 30 adult healthy Wistar male rats, with body mass of (200±20) g, were enrolled. Ten rats were chosen as the donors of allogenic nerve transplantation. The other 20 rats were randomly divided into 2 groups: allogenic nerve embedment group and autologous nerve embedment group, with 10 rats in each one.JEM-1220 transmission electron microscope (Japan) and Olympus BX50 optical microscope (Japan) were used.METHODS: This experiment was carried out at the laboratory of Orthopaedic Department, Chongqing Medical University from October 2000 to April 2002. ① Sciatic nerve of donor rats for allogenic nerve transplantation was cut off at 5 mm distant from pelvic strait.15 mm sciatic nerve segment was chosen from lateral part as graft. Allogenic nerve embedment group: 15 mm sciatic nerve form the donor rats was embedded in the posterior part of right legs. Autologous nerve embedment group: 15 mm sciatic nerve segment of autologous left side was embedded in the posterior side of right legs. ② Nerve segment embedded subcutaneously was taken out at postoperative 2 weeks and performed gross observation; then 5 samples chosen randomly respectively from 2 groups and given haematoxylin-eosin staining and observation under optical microscope (×400);The other 5 samples were made into ultrathin sections (0.5 μm)and observed under transmission electron

  15. Axillobifemoral bypass grafting

    Directory of Open Access Journals (Sweden)

    Davidović Lazar B.

    2004-01-01

    Full Text Available INTRODUCTION Axillo-femoral bypass (AxF means connecting the axillar and femoral artery with the graft that is placed subcutaneously [1]. Usually, this graft is connected with contralateral femoral artery via one accessory subcutaneous graft, and this connection is known as axillobifemoral bypass (AxFF. This extra-anatomic procedure is an alternative method to the standard reconstruction of aortoiliac region when there are contraindications for general or local reasons. OBJECTIVE The objective of this paper is to show early and late results of AxFF bypass grafting as well as to show the indications for AxFF bypass. METHODS The sample consisted of 37 patients. The procedure was performed in 28 patients who suffered from aortoiliac occlusive disease and who were at high risk due to the comorbidity- in one patient with the rupture of juxtarenal aneurysm of abdominal aorta; in five patients with aortoenteric fistula, in two patients with iatrogenic lesion of abdominal aorta and in one female patient with anus preternaturalis definitivus who was treated for rectovaginal fistula. Donor's right axillary artery was used in 26 cases (70.3%, and donor's left axillary artery was used in 9 cases (29.7%. Dacron graft was used in 34 patients and Polytetrafluo-roethlylene graft was used in three patients. Simultaneously, profundo-plastic was done in four patients and femoro-popliteal bypass was performed in three patients. In five patients who suffered from aortoenteric fistula, simultaneous intervention of gastrointerstinal system has been done, x2 test was used for statistical evaluation and life table method was used for verification of late graft patency. RESULTS The rate of early postoperative mortality was 13.5%. The causes of death were: sepsis -1, MOFS - 3, and infarct myocardium -1. The mean follow up period was 40.1 months, ranging from six months to 17 years. During the follow up period, an early graft thrombosis was identified in two and late graft

  16. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch;

    2005-01-01

    glaucoma patients is six times higher at a perfusion pressure of 30 mmHg, which corresponds to a level where the optic nerve is hypoxic in experimental animals, as compared to perfusion pressure levels above 50 mmHg where the optic nerve is normoxic. Medical intervention can affect optic nerve oxygen...... through a mechanism of vasodilatation and lowering of the intraocular pressure. Carbonic anhydrase inhibition reduces the removal of CO2 from the tissue and the CO2 accumulation induces vasodilatation resulting in increased blood flow and improved oxygen supply. This effect is inhibited by the cyclo...

  17. Radial Nerve Tendon Transfers.

    Science.gov (United States)

    Cheah, Andre Eu-Jin; Etcheson, Jennifer; Yao, Jeffrey

    2016-08-01

    Radial nerve palsy typically occurs as a result of trauma or iatrogenic injury and leads to the loss of wrist extension, finger extension, thumb extension, and a reduction in grip strength. In the absence of nerve recovery, reconstruction of motor function involves tendon transfer surgery. The most common donor tendons include the pronator teres, wrist flexors, and finger flexors. The type of tendon transfer is classified based on the donor for the extensor digitorum communis. Good outcomes have been reported for most methods of radial nerve tendon transfers as is typical for positional tendon transfers not requiring significant power. PMID:27387076

  18. Arteriovenous shunt graft ulceration with sinus and graft epithelialization

    Directory of Open Access Journals (Sweden)

    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.

  19. Diabetic Nerve Problems

    Science.gov (United States)

    ... at the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get ... you change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. ...

  20. The Use of Fiber-Reinforced Scaffolds Cocultured with Schwann Cells and Vascular Endothelial Cells to Repair Rabbit Sciatic Nerve Defect with Vascularization

    OpenAIRE

    Hongyang Gao; Yang You; Guoping Zhang; Feng Zhao; Ziyi Sha; Yong Shen

    2013-01-01

    To explore the feasibility of biodegradable fiber-reinforced 3D scaffolds with satisfactory mechanical properties for the repair of long-distance sciatic nerve defect in rabbits and effects of vascularized graft in early stage on the recovery of neurological function, Schwann cells and vascular endothelial cells were cocultured in the fiber-reinforced 3D scaffolds. Experiment group which used prevascularized nerve complex for the repair of sciatic nerve defect and control group which only cul...

  1. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T;

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  2. Nerve Conduction Studies and Electromyography

    OpenAIRE

    Keyes, Robert D.

    1990-01-01

    Nerve conduction studies and electromyography can aid in the diagnosis of peripheral nervous system disease. The author reviews various techniques used during electromyography and nerve conduction studies. He reviews briefly peripheral nerve and muscle neuroanatomy and neurophysiology. The author defines terms used in nerve conduction studies and electromyography and relates terminology to the underlying pathophysiology and histopathology. He also reviews briefly typical nerve conduction and ...

  3. In vivo testing of a 3D bifurcating microchannel scaffold inducing separation of regenerating axon bundles in peripheral nerves

    NARCIS (Netherlands)

    Stoyanova, Irina I.; Wezel, van Richard J.A.; Rutten, Wim L.C.

    2013-01-01

    Artificial nerve guidance channels enhance the regenerative effectiveness in an injured peripheral nerve but the existing design so far has been limited to basic straight tubes simply guiding the growth to bridge the gap. Hence, one of the goals in development of more effective neuroprostheses is to

  4. Slicing, skinning, and grafting

    OpenAIRE

    Dumas, David; Kent IV, Richard P.

    2007-01-01

    We prove that a Bers slice is never algebraic, meaning that its Zariski closure in the character variety has strictly larger dimension. A corollary is that skinning maps are never constant. The proof uses grafting and the theory of complex projective structures.

  5. Acrylonitrile grafted to PVDF

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jin; Eitouni, Hany Basam

    2015-03-31

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

  6. [Biophysics of nerve excitation].

    Science.gov (United States)

    Kol'e, O R; Maksimov, G V

    2010-01-01

    The studies testifying to the presence of the interrelation between the physiological functions of the organism and physical and chemical processes in nerves are discussed. Changes in some physical and chemical parameters observed both upon elicited rhythmic exaltation of nerves and during the spontaneous rhythmic activity of neurons are analyzed. Upon rhythmic exaltation, a complex of physical and chemical processes is triggered, and reversible structural and metabolic rearrangements at the subcellular and molecular levels occur that do not take place during the generation of a single action potential. Thus, only in conditions of rhythmic exaltation of a nerve, it is possible to reveal those processes that provide exaltation of nerves in the organism. The future possibilities of the investigations combining the biophysical and physiological approaches are substantiated. Characteristic changes in physicochemical parameters are observed in nerves during the generation of a series of action potentials of different frequency and duration ("frequency dependence") under normal physiological conditions, as well as in extreme situations and in nerve pathology. The structural and metabolic rearrangements are directly related to the mode of rhythmic exaltation and proceed both in the course of rhythmic exaltation and after its termination. Participation and the basic components of the nervous fulcrum (an axon, Shwan cell, myelin, subcellular organelles) in the realization of rhythmic exaltation is shown. In the coordination of all processes involved in rhythmic exaltation, the main role is played by the systems of redistribution and transport of intercellular and endocellular calcium. The idea is put forward that myelin of nerve fibers is not only an isolator, but also an "intercellular depot" of calcium and participates in the redistribution of different ions. Thus, the rhythmic excitation is of great importance in the realization of some physiological functions, the

  7. Retrograde tracing of fluorescent gold after autogenous nerve transplantation on spinal cord injured in rats

    DEFF Research Database (Denmark)

    Lin, X; Liu, W; Ding, Ming;

    2016-01-01

    Objective To investigate the changes of the fluorescent gold retrograde tracing autogenous nerve transplantation on spinal cord injured in rats. Methods The animals were divided into two groups, with modified Allen impact method to establish model of spinal cord injury. After 4 weeks, the...... transplantation group using autologous sural nerve graft to repair spinal cord injury period and non-transplantation group was only exposed incision without treatment. In the 4, 6 and 8 weeks after operation, the retrograde tracing of FG Fluoro-Gold was performed to discover the recovery of the axial plasma.......01). Conclusion After spinal cord injury, autologous nerve graft was repaired and survived well and promote the recovery of spinal cord injury segment shaft pulp transportation function....

  8. Storage and allogeneic transplantation of peripheral nerve using a green tea polyphenol solution in a canine model

    Directory of Open Access Journals (Sweden)

    Noguchi Takashi

    2010-11-01

    Full Text Available Abstract Background In our previous study, allogeneic-transplanted peripheral nerve segments preserved for one month in a polyphenol solution at 4°C could regenerate nerves in rodents demonstrated the same extent of nerve regeneration as isogeneic fresh nerve grafts. The present study investigated whether the same results could be obtained in a canine model. Methods A sciatic nerve was harvested from a male beagle dog, divided into fascicules of Sry and β-actin to investigate whether cells of donor origin remained in the allogeneic nerve segments. FK506 concentration was measured in blood samples taken before the animals were killed. Results The total myelinated axon numbers and amplitudes of the muscle action potentials correlated significantly with the blood FK506 concentration. Few axons were observed in the allogeneic-transplanted nerve segments in the PA0.025 group. PCR showed clear Sry-specific bands in specimens from the PA0.1 and PA0.05 groups but not from the PA0.025 group. Conclusions Successful nerve regeneration was observed in the polyphenol-treated nerve allografts when transplanted in association with a therapeutic dose of FK506. The data indicate that polyphenols can protect nerve tissue from ischemic damage for one month; however, the effects of immune suppression seem insufficient to permit allogeneic transplantation of peripheral nerves in a canine model.

  9. Study of synergistic role of allogenic skin-derived precursor differentiated Schwann cells and heregulin-1β in nerve regeneration with an acellular nerve allograft.

    Science.gov (United States)

    Wang, Houlei; Wu, Jingping; Zhang, Xinchao; Ding, Lei; Zeng, Qingmin

    2016-07-01

    Development of tissue structure and three-dimensional microenvironment is crucial for regeneration of axons in the peripheral nerve repair. In this study we aimed to evaluate the efficacy of nerve regeneration by using an acellular nerve allograft (ANA) injected with allogenic skin-derived precursor differentiated Schwann cells (SKP-SCs) and heregulin-1β. Skin-derived precursor cells (SKPs) were generated from dermis of newborn (postnatal day 2) Wistar rats. In a rat model, nerve regeneration was determined across a 15 mm lesion in the sciatic nerve by using an ANA injected with allogenic SKP-SCs and heregulin-1β. The electrophysiological analysis, histological examination and electron microscopy were involved in this study. Cultured SKPs expressed nestin and fibronectin, and differentiated into cells with phenotype of SCs that presented characteristic markers of p75NGFR and S100-β. Implantation of SKP-SCs into the rat models by using ANA and allogenic skin-derived precursor differentiated Schwann cells (SKP-SCs) increases sciatic nerve functional index (SFI), peak amplitudes, nerve conduction velocities, number of myelinated fibers within the graft, while reduces incubation period, sciatic nerve injury-induced weight and contractions loss. Using ANA injected with SKP-SCs combined with heregulin-1β greatly promote peripheral nerve repair in a rat model. Our results suggest that SKP-SCs transplantation with heregulin-1β represents a powerful therapeutic approach, and facilitates the efficacy of acellular nerve allograft in peripheral nerve injury, though the detailed mechanism remains to be elucidated. PMID:27063890

  10. Cranial nerve palsies

    International Nuclear Information System (INIS)

    This paper evaluates the utility of multiplanar reconstructions (MPRs) of three-dimensional (3D) MR angiography data sets in the examination of patients with cranial nerve palsies. The authors hypothesis was that 3D data could be reformatted to highlight the intricate spatial relationships of vessels to adjacent neural tissues by taking advantage of the high vessel-parenchyma contrast in high-resolution 3D time-of-flight sequences. Twenty patients with cranial nerve palsies and 10 asymptomatic patients were examined with coronal T1-weighted and axial T2-weighted imaging plus a gadolinium-enhanced 3D MRA sequence (40/7/15 degrees, axial 60-mm volume, 0.9-mm isotropic resolution). Cranial nerves II-VIII were subsequently evaluated on axial and reformatted coronal and/or sagittal images

  11. Artificial Economy

    Directory of Open Access Journals (Sweden)

    Alexandru JIVAN

    2011-08-01

    Full Text Available This paper proposes to eliminate, a routine in the economic thinking, claimed to be responsible for the negative essence of economic developments, from the point of view, of the ecological implications (employment in the planetary ecosystem. The methodological foundations start from the natural origins of the functionality of the human economic society according to the originary physiocrat liberalism, and from specific natural characteristics of the humankind. This paper begins with a comment-analysis of the difference between natural and artificial within the economy, and then explains some of the most serious diversions from the natural essence of economic liberalism. It shall be explained the original (heterodox interpretation of the Classical political economy (economics, by making calls to the Romanian economic thinking from aggravating past century. Highlighting the destructive impact of the economy - which, under the invoked doctrines, we call unnatural - allows an intuitive presentation of a logical extension of Marshall's market price, based on previous research. Besides the doctrinal arguments presented, the economic realities inventoried along the way (major deficiencies and effects, determined demonstrate the validity of the hypothesis of the unnatural character and therefore necessarily to be corrected, of the concept and of the mechanisms of the current economy.The results of this paper consist of original heterodox methodspresented, intuitive or developed that can be found conclusively within the key proposals for education and regulation.

  12. Nerve Transfers in Tetraplegia.

    Science.gov (United States)

    Fox, Ida K

    2016-05-01

    Hand and upper extremity function is instrumental to basic activities of daily living and level of independence in cervical spinal cord injury (SCI). Nerve transfer surgery is a novel and alternate approach for restoring function in SCI. This article discusses the biologic basis of nerve transfers in SCI, patient evaluation, management, and surgical approaches. Although the application of this technique is not new; recent case reports and case series in the literature have increased interest in this field. The challenges are to improve function, achieve maximal gains in function, avoid complications, and to primum non nocere. PMID:27094894

  13. Neuromuscular Ultrasound of Cranial Nerves

    OpenAIRE

    Tawfik, Eman A.; Walker, Francis O.; Cartwright, Michael S.

    2015-01-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few re...

  14. High division of sciatic nerve

    OpenAIRE

    Tripti Shrivastava; Lalit Garg; B. K. Mishra; Neeta Chhabra

    2014-01-01

    Background: The Sciatic nerve is the largest and thickest nerve in the human body with a long course in the inferior extremity. It divides into tibial and common peroneal nerves which can occur at any level from the sacral plexus to the inferior part of the popliteal space. Sciatic nerve variations are relatively common. These variations may contribute to clinical conditions ex sciatica, coccygodynia and piriformis syndrome and have important clinical implications in anaesthesiology, neurolog...

  15. Progress of peripheral nerve repair

    Institute of Scientific and Technical Information of China (English)

    陈峥嵘

    2002-01-01

    Study on repair of peripheral nerve injury has been proceeding over a long period of time. With the use of microsurgery technique since 1960s,the quality of nerve repair has been greatly improved. In the past 40 years, with the continuous increase of surgical repair methods, more progress has been made on the basic research of peripheral nerve repair.

  16. Tumors of the optic nerve

    DEFF Research Database (Denmark)

    Lindegaard, Jens; Heegaard, Steffen

    2009-01-01

    the nerve (e.g., astrocytes and meningothelial cells). The optic nerve may also be invaded from tumors originating elsewhere (secondary tumors), invading the nerve from adjacent structures (e.g., choroidal melanoma and retinoblastoma) or from distant sites (e.g., lymphocytic infiltration and distant...

  17. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T;

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta...

  18. Vascular graft infections with Mycoplasma

    DEFF Research Database (Denmark)

    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....

  19. Long-term outcomes of internal carotid artery disease treated using radial artery graft

    International Nuclear Information System (INIS)

    Complex internal carotid artery disease presents a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict occurrence of ischemic complications after internal carotid artery ligation. The present study concerns long-term clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2007, we performed radial artery grafting followed immediately by parent artery occlusion in 20 sides of 19 patients with complex internal carotid arteries disease with follow-up for more than 36 months (5 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative MRI and MR angiography (MRA) every year to assess graft patency, ischemic complications, and de novo aneurysm. Another 20 carotid aneurysms with visual disturbance were assessed concerning outcome. Among 13 patients with cranial nerve (III and VI) disturbances, all dysfunctions were improved in cases treated within 8 months of onset to operation. On the other hand, patients with second cranial nerve disturbances were not improved in cases treated after 4 months of onset. No long-term complications were discovered with MRI and MRA. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Long-term safety is satisfactory, with no delayed complications such as graft stenosis, ischemic complications or de novo aneurysm formations in follow-up periods of more than 3 years. Good clinical outcome of cranial nerve palsy was achieved in patients treated within 8 months of onset for cranial nerve (CN) III and VI, and 4 of CN II palsy. (author)

  20. Environmental application of radiation grafting

    International Nuclear Information System (INIS)

    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)

  1. Pathology of the vestibulocochlear nerve

    Energy Technology Data Exchange (ETDEWEB)

    De Foer, Bert [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: bert.defoer@GZA.be; Kenis, Christoph [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: christophkenis@hotmail.com; Van Melkebeke, Deborah [Department of Neurology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Deborah.vanmelkebeke@Ugent.be; Vercruysse, Jean-Philippe [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: jphver@yahoo.com; Somers, Thomas [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Thomas.somers@GZA.be; Pouillon, Marc [Department of Radiology, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: marc.pouillon@GZA.be; Offeciers, Erwin [University Department of ENT, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium)], E-mail: Erwin.offeciers@GZA.be; Casselman, Jan W. [Department of Radiology, AZ Sint-Jan AV Hospital, Ruddershove 10, Bruges (Belgium); Consultant Radiologist, Sint-Augustinus Hospital, Oosterveldlaan 24, 2610 Wilrijk (Belgium); Academic Consultent, University of Ghent (Belgium)], E-mail: jan.casselman@azbrugge.be

    2010-05-15

    There is a large scala of pathology affecting the vestibulocochlear nerve. Magnetic resonance imaging is the method of choice for the investigation of pathology of the vestibulocochlear nerve. Congenital pathology mainly consists of agenesis or hypoplasia of the vestibulocochlear nerve. Tumoral pathology affecting the vestibulocochlear nerve is most frequently located in the internal auditory canal or cerebellopontine angle. Schwannoma of the vestibulocochlear nerve is the most frequently found tumoral lesion followed by meningeoma, arachnoid cyst and epidermoid cyst. The most frequently encountered pathologies as well as some more rare entities are discussed in this chapter.

  2. Nanostructured Guidance for Peripheral Nerve Injuries: A Review with a Perspective in the Oral and Maxillofacial Area

    Directory of Open Access Journals (Sweden)

    Stefano Sivolella

    2014-02-01

    Full Text Available Injury to peripheral nerves can occur as a result of various surgical procedures, including oral and maxillofacial surgery. In the case of nerve transaction, the gold standard treatment is the end-to-end reconnection of the two nerve stumps. When it cannot be performed, the actual strategies consist of the positioning of a nerve graft between the two stumps. Guided nerve regeneration using nano-structured scaffolds is a promising strategy to promote axon regeneration. Biodegradable electrospun conduits composed of aligned nanofibers is a new class of devices used to improve neurite extension and axon outgrowth. Self assembled peptide nanofibrous scaffolds (SAPNSs demonstrated promising results in animal models for central nervous system injuries, and, more recently, for peripheral nerve injury. Aims of this work are (1 to review electrospun and self-assembled nanofibrous scaffolds use in vitro and in vivo for peripheral nerve regeneration; and (2 its application in peripheral nerve injuries treatment. The review focused on nanofibrous scaffolds with a diameter of less than approximately 250 nm. The conjugation in a nano scale of a natural bioactive factor with a resorbable synthetic or natural material may represent the best compromise providing both biological and mechanical cues for guided nerve regeneration. Injured peripheral nerves, such as trigeminal and facial, may benefit from these treatments.

  3. Solvent and irradiation doses effects on the ion exchange capacity of sulfonated styrene grafted PVDF

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Polymers exhibiting ion exchange capacity are studied for many years due to their application in several fields, such as membranes for proton exchange fuel cells, filtration membranes, heavy ions recovery and artificial muscles and sensors. Radiation induced grafting followed by sulfonation is a well-known way to obtain ion exchange polymers. Fluorinated polymers are frequently used as polymeric matrix for grafting due to their excellent physicochemical properties. Radiation induced grafting of styrene into poly (vinylidene fluoride) (PVDF) by simultaneous method in 1:1 styrene/toluene or styrene/N,N-dimethylformamide solutions was studied. Irradiations were performed under nitrogen atmosphere, room temperature and at doses of 5, 10 and 20 kGy with dose rate of 5 kGy.h{sup -1} from a {sup 60}Co gamma source. After washing, grafted materials were sulfonated in 10% chlorosulfonic acid/1,2-dichloroethane solutions for 4 h at room temperature. Characterization shows that increasing irradiation dose corresponds to increases in the grafting yield (GY %) gravimetrically calculated and these different solvents shows different grafting behaviors. Toluene allows no more than 3 % of grafting while DMF allows up to 55 % of grafting in the same condition. Grafting in toluene solution occurs on the surface and in DMF solution it occurs in the bulk, as confirmed by SEM. Both irradiation doses and solvent used have direct effects in the ion exchange capacities (calculated after titrations). FT-IR spectra exhibit new peaks after grafting and after sulfonation, attributed to grafted monomer and sulfonic groups attached to the styrene. DSC shows differences in thermal behavior of the polymer before and after each step. (author)

  4. Preferential and comprehensive reconstitution of severely damaged sciatic nerve using murine skeletal muscle-derived multipotent stem cells.

    Directory of Open Access Journals (Sweden)

    Tetsuro Tamaki

    Full Text Available Loss of vital functions in the somatic motor and sensory nervous systems can be induced by severe peripheral nerve transection with a long gap following trauma. In such cases, autologous nerve grafts have been used as the gold standard, with the expectation of activation and proliferation of graft-concomitant Schwann cells associated with their paracrine effects. However, there are a limited number of suitable sites available for harvesting of nerve autografts due to the unavoidable sacrifice of other healthy functions. To overcome this problem, the potential of skeletal muscle-derived multipotent stem cells (Sk-MSCs was examined as a novel alternative cell source for peripheral nerve regeneration. Cultured/expanded Sk-MSCs were injected into severely crushed sciatic nerve corresponding to serious neurotmesis. After 4 weeks, engrafted Sk-MSCs preferentially differentiated into not only Schwann cells, but also perineurial/endoneurial cells, and formed myelin sheath and perineurium/endoneurium, encircling the regenerated axons. Increased vascular formation was also observed, leading to a favorable blood supply and waste product excretion. In addition, engrafted cells expressed key neurotrophic and nerve/vascular growth factor mRNAs; thus, endocrine/paracrine effects for the donor/recipient cells were also expected. Interestingly, skeletal myogenic capacity of expanded Sk-MSCs was clearly diminished in peripheral nerve niche. The same differentiation and tissue reconstitution capacity of Sk-MSCs was sufficiently exerted in the long nerve gap bridging the acellular conduit, which facilitated nerve regeneration/reconnection. These effects represent favorable functional recovery in Sk-MSC-treated mice, as demonstrated by good corduroy walking. We also demonstrated that these differentiation characteristics of the Sk-MSCs were comparable to native peripheral nerve-derived cells, whereas the therapeutic capacities were largely superior in Sk

  5. Tissue banking and clinical research on radiation and ethylene oxide sterilization of tissue grafts

    International Nuclear Information System (INIS)

    The research works carried out in Rangoon, Burma under the Agency supported project RC4420/RB have dealt with an elucidation of the radiation interaction(s) with the species of biomolecules such as proteins, lipids, collagens, connective tissues present in the cleaned and freeze-dried non-viable tissue grafts. Radiation as a cool process furthermore effectively helps to destroy the microbial bioburden as the undesirable contaminants which may associate the tissue grafts. Radiation also concomitantly helps to suppress the tissue-specific immunogenicity. All these attributes of radiation induced effects have proved successful towards the development of a sterilization process. A series of non-viable tissue grafts, such as bone, nerve, fascia, dura, cartilage, chorion-amnion (as dressings in burn wounds) and tympanic membrane have been successfully attempted in Burma and many more possibilities seem to still remain unexplored. Radiation sterilization modality has proved as a blessing for the promotion of clinical surgical applications of tissue allografts in the corrective/reconstructive surgery on the disability cases due to diseases which accompany tissue losses. The investigator in Burma has reported on the case histories where freeze dried radiation sterilized tissue allografts have been successfully used in the osteogenic inductions (bone grafts); midear tympanoplasty; partial recovery of nerve sensation throught nerve allografts; rapid healing of high degree burn wounds through the use of amnion dressings. Besides, there have been a widespread surgical use of radiation sterilized dura and fascia as allografts. A national tissue banking facility has been established in Burma surrounding the processing and clinical utilization of tissue allografts which has involved over ten hospital centres throughout the country. Radiation induced effects on the biomolecules of clinical significance in the tissue grafts have been researched to help gain insight into a better

  6. Progesterone and peripheral nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Fei Fan; Haichao Li; Yuwei Wang; Yanglin Zheng; Lianjun Jia; Zhihui Wang

    2006-01-01

    OBJECTIVE: To explore the effect of progesterone on peripheral nerve regeneration.DATA SOURCES: An online search of Medline and OVID databases was under taken to identify articles about progesterone and peripheral nerve regeneration published in English between January 1990 and June 2004 by using the keywords of "peripheral nerve, injury, progesterone, regeneration".STUDY SELECTION: The data were primarily screened, those correlated with progesterone and peripheral nerve regeneration were involved, and their original articles were further searched, the repetitive studies or reviews were excluded.DATA EXTRACTION: Totally 59 articles about progesterone and peripheral nerve regeneration were collected, and 26 of them were involved, the other 33 excluded ones were the repetitive studies or reviews.DATA SYNTHESIS: Recent researches found that certain amount of progesterone could be synthetized in peripheral nervous system, and the expression of progesterone receptor could be found in sensory neurons and Schwann cells. After combined with the receptor, endogenous and exogenous progesterone can accelerate the formation of peripheral nerve myelin sheath, also promote the axonal regeneration.CONCLUSION: Progesterone plays a role in protecting neurons, increasing the sensitivity of nerve tissue to nerve growth factor, and accelerating regeneration of nerve in peripheral nerve regeneration, which provides theoretical references for the treatment of demyelinated disease and nerve injury, as well as the prevention of neuroma, especially that the in vivo level of progesterone should be considered for the elderly people accompanied by neuropathy and patients with congenital luteal phase defect, which is of positive significance in guiding the treatment.

  7. Antimicrobial Graft Copolymer Gels.

    Science.gov (United States)

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

    2016-08-01

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

  8. Serious axillary nerve injury caused by subscapular artery compression resulting from use of backpacks.

    Science.gov (United States)

    Haninec, Pavel; Mencl, Libor; Bačinský, Peter; Kaiser, Radek

    2013-12-01

    A palsy of the brachial plexus elements caused by carrying a heavy backpack is a very rare injury usually occurring in soldiers or hikers, and recovery is usually spontaneous. We describe here the case of male civilian presenting with an isolated serious axillary nerve palsy associated with chronic backpack use. During the surgery, a dumbbell-shaped neuroma-in-continuity was found which was caused by direct pressure from the subscapular artery. After resection of the neuroma, a nerve graft from the sural nerve was used to reconstruct the nerve. Reinnervation was successful and the patient was able to abduct his arm to its full range, with full muscle strength, within 24 months. PMID:23696291

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Design of a Sapling Branch Grafting Robot

    OpenAIRE

    Qun Sun; Dongjie Zhao; Chong Wang; Ying Zhao

    2014-01-01

    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 bindi...

  11. Grafting Genetically Modified Cells to the Damaged Brain: Restorative Effects of NGF Expression

    Science.gov (United States)

    Rosenberg, Michael B.; Friedmann, Theodore; Robertson, Robin C.; Tuszynski, Mark; Wolff, Jon A.; Breakefield, Xandra O.; Gage, Fred H.

    1988-12-01

    Fibroblasts were genetically modified to secrete nerve growth factor (NGF) by infection with a retroviral vector and then implanted into the brains of rats that had surgical lesions of the fimbria-fornix. The grafted cells survived and produced sufficient NGF to prevent the degeneration of cholinergic neurons that would die without treatment. In addition, the protected cholinergic cells sprouted axons that projected in the direction of the cellular source of NGF. These results indicate that a combination of gene transfer and intracerebral grafting may provide an effective treatment for some disorders of the central nervous system.

  12. Functionalizing artificial nerve guides to promote regeneration and recovery after peripheral nerve injuries

    OpenAIRE

    González Pérez, Francisco J.

    2016-01-01

    Las lesiones severas de nervio periférico se caracterizan por la desconexión del soma neuronal con el órgano inervado. Esta desconexión causa una pérdida de control motor, sensitivo y autonómico que conducen a una situación incapacitante para el paciente. Después de una lesión el sistema nervioso periférico tiene la capacidad de regenerar, pero para ello se requiere de un proceso de limpieza en el fragmento distal a la lesión y la promoción de la regeneración a través del extremo proximal. ...

  13. Bone Grafting the Cleft Maxilla

    Science.gov (United States)

    ... systemic disease such as diabetes, or has poor oral hygiene, the risk that the graft may fail increases even more. Once the bone graft has been placed, there are three options that ... replacement (dental bridge); or 3) dental metallic bone implants. The ...

  14. Polyether/Polyester Graft Copolymers

    Science.gov (United States)

    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.

  15. Collapse of grafted polyelectrolyte layer

    OpenAIRE

    Borisov, O.; Birshtein, T.; Zhulina, E.

    1991-01-01

    The theory describing chain conformation in a planar layer of grafted polyelectrolyte (polyampholyte) molecules and the conformational transition related to the collapse of this layer caused by the decrease in solvent strenght is developed. Depending on the values of the layer parameters (grafting and charge densities) this transition may occur as a continuous (cooperative) or as a first order phase transition.

  16. Optic nerve hypoplasia

    Directory of Open Access Journals (Sweden)

    Savleen Kaur

    2013-01-01

    Full Text Available Optic nerve hypoplasia (ONH is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65% than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED.

  17. Optic nerve hypoplasia.

    Science.gov (United States)

    Kaur, Savleen; Jain, Sparshi; Sodhi, Harsimrat B S; Rastogi, Anju; Kamlesh

    2013-05-01

    Optic nerve hypoplasia (ONH) is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65%) than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED). PMID:24082663

  18. Grafting techniques for Peyronie's disease.

    Science.gov (United States)

    Hatzichristodoulou, Georgios

    2016-06-01

    Peyronie's disease (PD) is a benign fibrotic condition of the penile tunica albuginea. PD can be associated with penile pain, curvature, shortening, and erectile dysfunction (ED). The predominant and most bothersome symptom in affected patients is penile curvature, which can lead to inability to have sexual intercourse. In such cases, surgical correction of the curvature may be required. Plication techniques to correct curvature can cause penile shortening and therefore are generally reserved for curvatures 60°, short penis, or hourglass deformity. Patients scheduled for grafting surgery are required to have satisfactory erectile rigidity preoperatively. There are various grafting materials that can be used for closure of the tunica albuginea defect following plaque incision/excision. Both autologous and non-autologous grafts have been used for PD reconstructive surgery, and each graft has its advantages and disadvantages. Novel grafting materials are presented and discussed in this review. A major advantage of the available "off-the-shelf" grafts is that there is no harvesting from a donor site and, thus, morbidity is reduced, and operative times are minimized. Further investigations in regard to tissue-engineered grafts to improve surgical handling and postoperative outcomes are ongoing. Surgeon experience, careful patient selection, patient preference and type of penile deformity affect the choice of graft. This review summarizes the literature within the past 5 years regarding grafting techniques in PD. Surgical outcomes and limitations of grafting techniques are reported. A major objective of this review is dedicated to preoperative considerations and indications for grafting procedures, with the aim to improve surgical outcomes and increase patient satisfaction. Proper postoperative management of patients after incision/excision and grafting is important to avoid early and long-term complications and unwanted outcomes. This review provides an overview of

  19. Electron beam grafting of polymers

    International Nuclear Information System (INIS)

    Electron beam (EB) grafting has been a well known technique for modifying the surfaces of materials for many years. Commercial implementation has been quite successful in a few, narrow niche markets. Irradiation grafting is being used to control ion flow through battery separator membranes, to modify the hydrophilic and hydrophobic properties of semi-permeable membranes and non-woven fabrics, to enhance the bio-compatibility of materials used in the medical device area, and to impart release properties to films and papers. The use of grafting to modify the bulk properties of materials has not as yet emerged as a widely accepted commercial practice. The development of lower voltage, more cost-effective self-shielded electron beam equipment presents opportunities for enhanced commercial development. The technology used in grafting is very specific to the selection of the base polymer and to the choice of the graft monomers. Different combinations can yield vastly different performance properties

  20. Nerve conduction and excitability studies in peripheral nerve disorders

    DEFF Research Database (Denmark)

    Krarup, Christian; Moldovan, Mihai

    2009-01-01

    counterparts in the peripheral nervous system, in some instances without peripheral nervous system symptoms. Both hereditary and acquired demyelinating neuropathies have been studied and the effects on nerve pathophysiology have been compared with degeneration and regeneration of axons. SUMMARY: Excitability....... Studies of different metabolic neuropathies have assessed the influence of uremia, diabetes and ischemia, and the use of these methods in toxic neuropathies has allowed pinpointing damaging factors. Various mutations in ion channels associated with central nervous system disorders have been shown to have......PURPOSE OF REVIEW: The review is aimed at providing information about the role of nerve excitability studies in peripheral nerve disorders. It has been known for many years that the insight into peripheral nerve pathophysiology provided by conventional nerve conduction studies is limited. Nerve...

  1. The treatment of peripheral nerve injuries using irradiated allografts and temporary host immunosuppression (in a rat model)

    International Nuclear Information System (INIS)

    Irradiation of allografts prior to transplantation and host immunosuppression with cyclosporin-A were studied separately and in combination as means of lessening the rejection of transplanted peripheral nerve tissue. Lewis and Brown Norway rats were used in the animal model, as they differ at both major and minor histocompatibility loci. Sciatic nerve grafts (2.5 cm) were used and the animals were followed for 16 weeks after nerve grafting. The outcome was studied by functional measurements (sensory testing, gait analysis, joint flexion contracture, and muscle weight), as well as by measurements of biochemical and histologic parameters (hydroxyproline concentration and axon counts, respectively). Sensory testing was not reliable because of crossover innervation by the saphenous nerve. Evaluation by standard gait-testing techniques was found to be unsatisfactory. However, the allografted animals receiving cyclosporin-A had significantly smaller flexion contractures, compared to the allografted animals without immunosuppression (17 degrees +/- 12 degrees vs. 44 degrees +/- 13 degrees and 51 degrees +/- 13 degrees, p less than 0.005). Allografted animals receiving short-term cyclosporin-A had contractures that were not significantly different from those seen in isografted control animals (17 degrees +/- 12 degrees vs. 22 degrees +/- 15 degrees, NS). Muscle hydroxyproline concentration analysis revealed a lower hydroxyproline concentration among the allografted groups that received irradiated allografts, compared to groups receiving nonirradiated allogeneic grafts. The studies of muscle hydroxyproline concentration and muscle weight both showed substantial reinnervation, even in allografted animals without pretreatment of the grafts or immunosuppression of the recipient animal

  2. Radiation grafting on natural films

    Science.gov (United States)

    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.

  3. Repair of sciatic nerve defects using tissue engineered nerves

    OpenAIRE

    Zhang, Caishun; Lv, Gang

    2013-01-01

    In this study, we constructed tissue-engineered nerves with acellular nerve allografts in Sprague-Dawley rats, which were prepared using chemical detergents-enzymatic digestion and mechanical methods, in combination with bone marrow mesenchymal stem cells of Wistar rats cultured in vitro, to repair 15 mm sciatic bone defects in Wistar rats. At postoperative 12 weeks, electrophysiological detection results showed that the conduction velocity of regenerated nerve after repair with tissue-engine...

  4. Application of Vascular grafts od Polyvinyl alcohol hydrogel associated to mesenchymal stem cells from whartons jelly in an animal model.

    OpenAIRE

    Alexandre, Nuno; Lopes, Ascensão; Nunes, Natacha; Amorim, Irina; Maurício, Ana Colette; Santos, José Domingos; Luís, Ana Lúcia

    2013-01-01

    Application of vascular grafts of the polyvinyl alcohol hydrogel (PVA) associated with MSCs from Wharton jelly in an animal model (sheep). N Alexandre, MA Lopes, N Fernandes, M Rodrigues, I Amorim, AC Mauricio, AL Luís Introduction: There is a great demand for new artificial vascular grafts of small diameter (< 6 mm) due to the functional limitations of the currently used biomaterials (ePTFE and Dacron). Polyvinyl alcohol hydrogel (PVA) is a biomaterial that has been used for several b...

  5. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

  6. N-Propionylmannosamine stimulates axonal elongation in a murine model of sciatic nerve injury

    Institute of Scientific and Technical Information of China (English)

    Christian Witzel; Werner Reutter; G Bjrn Stark; Georgios Koulaxouzidis

    2015-01-01

    Increasing evidence indicates that sialic acid plays an important role during nerve regeneration. Sialic acids can be modiifed in vitro as well as in vivo using metabolic oligosaccharide engineering of the N-acyl side chain. N-Propionylmannosamine (ManNProp) increases neurite outgrowth and accelerates the reestablishment of functional synapses in vitro. We investigated the inlfuence of systemic ManNProp application using a speciifc in vivo mouse model. Using mice expressing axonal lfuorescent proteins, we quantiifed the extension of regenerating axons, the number of regenerating axons, the number of arborising axons and the number of branches per axon 5 days after injury. Sciatic nerves from non-expressing mice were grafted into those expressing yellow lfuorescent protein. We began a twice-daily intraperitoneal application of either peracetylated ManNProp (200 mg/kg) or saline solution 5 days before injury, and continued it until nerve harvest (5 days after transection). ManNProp signiifcantly increased the mean distance of axonal regeneration (2.49 mm vs. 1.53 mm;P<0.005) and the number of arborizing axons (21%vs. 16%;P=0.008) 5 days after sciatic nerve grafting. ManNProp did not affect the number of regenerating axons or the number of branches per arborizing axon. The biochemical glycoen-gineering of the N-acyl side chain of sialic acid might be a promising approach for improving peripheral nerve regeneration.

  7. N-Propionylmannosamine stimulates axonal elongation in a murine model of sciatic nerve injury

    Directory of Open Access Journals (Sweden)

    Christian Witzel

    2015-01-01

    Full Text Available Increasing evidence indicates that sialic acid plays an important role during nerve regeneration. Sialic acids can be modified in vitro as well as in vivo using metabolic oligosaccharide engineering of the N-acyl side chain. N-Propionylmannosamine (ManNProp increases neurite outgrowth and accelerates the reestablishment of functional synapses in vitro. We investigated the influence of systemic ManNProp application using a specific in vivo mouse model. Using mice expressing axonal fluorescent proteins, we quantified the extension of regenerating axons, the number of regenerating axons, the number of arborising axons and the number of branches per axon 5 days after injury. Sciatic nerves from non-expressing mice were grafted into those expressing yellow fluorescent protein. We began a twice-daily intraperitoneal application of either peracetylated ManNProp (200 mg/kg or saline solution 5 days before injury, and continued it until nerve harvest (5 days after transection. ManNProp significantly increased the mean distance of axonal regeneration (2.49 mm vs. 1.53 mm; P < 0.005 and the number of arborizing axons (21% vs. 16% P = 0.008 5 days after sciatic nerve grafting. ManNProp did not affect the number of regenerating axons or the number of branches per arborizing axon. The biochemical glycoengineering of the N-acyl side chain of sialic acid might be a promising approach for improving peripheral nerve regeneration.

  8. Videoradiography of free jejunal grafts for rehabilitation of speech in laryngectomized patients

    International Nuclear Information System (INIS)

    In laryngectomized patients a tracheo-esophageal artificial fistula can be used to achieve air flow from the trachea to the esophagus during speech. A one-way plastic valve is often used for the fistula. A free jejunal graft between the trachea and the esophagus can also be used. To avoid aspiration the transplant is attached to the submental area giving the graft a siphon-like shape. We performed 23 videoradiographic examinations using high-density barium in 14 such patients. The aim was to evaluate the protective function of these grafts against aspiration. Penetration of the bolus and a small amount of residual contrast material in the ascending limb of the graft was a normal finding. If the standard barium bolus reached the descending limb at any time during the examination, this was a sign of aspiration hazard. To avoid aspiration, the vertex of the speech siphon should be higher than the level of the hypopharyngeal anastomosis. (orig.)

  9. Improvement of antithrombogenicity of a fluoro polymer by radiation-induced grafting of hydrophilic monomer

    International Nuclear Information System (INIS)

    Fluoro polymers have been used as biomaterials in medical field since they have good compatibility with both tissue and blood, and their biomaterial application are of variety. Blood compatibility of fluoro polymers, however, are not always enough for every applications. Especially, there is a large difficulty in the application for artificial vessel with small radius below than 4 mm. In the present study, grafting of a hydrophilic monomer onto a fluoro polymer has been carried out to improve blood compatibility of the fluoro polymer. The technique of grafting employed here was simultaneous irradiation method of gamma rays from a 60Co source. The fluoro polymer and the hydrophilic monomer used in the experiment were alternative copolymer of ethylene and tetrafluoethylene(AFLON) and N,N-dimethylacry lamide(DMAA), respectively. After grafting, it was found by in vitro tests that antithrombogenicity of AFLON was improved by grafting of DMAA. It was, however, also found that degree of the improvement is affected by grafting conditions. When ethyl acetate was used as a solvent for the graft copolymerization, the improvement was affected by dose rate. Blood compatibility of DMAA-g-AFLON obtained at a higher dose rate of 1 x 105 rad/h was not improved, while it was improved in the sample of DMAA-g-AFLON obtained at a lower dose rate of 1 x 104 rad/h. On the other hand, when acetone was used as a solvent for the grafting, the degree of grafting gave a significant effect on the improvement. Blood compatibility of all samples with grafting percent more than 20 % was improved by grafting of DMAA. (author)

  10. Evidence-based outcomes following inferior alveolar and lingual nerve injury and repair: a systematic review.

    Science.gov (United States)

    Kushnerev, E; Yates, J M

    2015-10-01

    The inferior alveolar nerve (IAN) and lingual (LN) are susceptible to iatrogenic surgical damage. Systematically review recent clinical evidence regarding IAN/LN repair methods and to develop updated guidelines for managing injury. Recent publications on IAN/LN microsurgical repair from Medline, Embase and Cochrane Library databases were screened by title/abstract. Main texts were appraised for exclusion criteria: no treatment performed or results provided, poor/lacking procedural description, cohort injury type, injury timing, neurosensory disturbances and intra-operative findings. Best functional nerve recovery occurred after direct apposition and suturing if nerve ending gaps were nerve grafting (sural/greater auricular nerve). Timing of microneurosurgical repair after injury remains debated. Most authors recommend surgery when neurosensory deficit shows no improvement 90 days post-diagnosis. Nerve transection diagnosed intra-operatively should be repaired in situ; minor nerve injury repair can be delayed. No consensus exists regarding optimal methods and timing for IAN/LN repair. We suggest a schematic guideline for treating IAN/LN injury, based on the most current evidence. We acknowledge that additional RCTs are required to provide definitive confirmation of optimal treatment approaches. PMID:26059454

  11. Artificial Inteligence and Law

    OpenAIRE

    Fuková, Kateřina

    2012-01-01

    Submitted diploma work Artificial Intelligence and Law deals with the rule of law and its position in the process of new advanced technologies in computer cybernetics and further scientific disciplines related with artificial intelligence and its creation. The first part of the work introduces the history of the first imagines about artificial intelligence and concerns with its birth. This chapter presents main theoretical knowledge and hypotheses defined artificial intelligence and progre...

  12. Artificial Skin in Robotics

    OpenAIRE

    Strohmayr, Michael

    2012-01-01

    Artificial Skin - A comprehensive interface for system-environment interaction - This thesis investigates a multifunctional artificial skin as touch sensitive whole-body cover for robotic systems. To further the evolution from tactile sensors to an implementable artificial skin a general concept for the design process is derived. A standard test procedure is proposed to evaluate the performance. The artificial skin contributes to a safe and intuitive physical human robot interaction.

  13. Incorporation of chitosan microspheres into collagen-chitosan scaffolds for the controlled release of nerve growth factor.

    Directory of Open Access Journals (Sweden)

    Wen Zeng

    Full Text Available Artifical nerve scaffold can be used as a promising alternative to autologous nerve grafts to enhance the repair of peripheral nerve defects. However, current nerve scaffolds lack efficient microstructure and neurotrophic support.Microsphere-Scaffold composite was developed by incorporating chitosan microspheres loaded with nerve growth factor (NGF-CMSs into collagen-chitosan scaffolds (CCH with longitudinally oriented microchannels (NGF-CMSs/CCH. The morphological characterizations, in vitro release kinetics study, neurite outgrowth assay, and bioactivity assay were evaluated. After that, a 15-mm-long sciatic nerve gap in rats was bridged by the NGF-CMSs/CCH, CCH physically absorbed NGF (NGF/CCH, CCH or nerve autograft. 16 weeks after implantation, electrophysiology, fluoro-gold retrograde tracing, and nerve morphometry were performed.The NGF-CMSs were evenly distributed throughout the longitudinally oriented microchannels of the scaffold. The NGF-CMSs/CCH was capable of sustained release of bioactive NGF within 28 days as compared with others in vitro. In vivo animal study demonstrated that the outcomes of NGF-CMSs/CCH were better than those of NGF/CCH or CCH.Our findings suggest that incorporation of NGF-CMSs into the CCH may be a promising tool in the repair of peripheral nerve defects.

  14. Small nerve fiber pathology in critical illness.

    Directory of Open Access Journals (Sweden)

    Nicola Latronico

    Full Text Available BACKGROUND: Degeneration of intraepidermal nerve fibers (IENF is a hallmark of small fiber neuropathy of different etiology, whose clinical picture is dominated by neuropathic pain. It is unknown if critical illness can affect IENF. METHODS: We enrolled 14 adult neurocritical care patients with prolonged intensive care unit (ICU stay and artificial ventilation (≥ 3 days, and no previous history or risk factors for neuromuscular disease. All patients underwent neurological examination including evaluation of consciousness, sensory functions, muscle strength, nerve conduction study and needle electromyography, autonomic dysfunction using the finger wrinkling test, and skin biopsy for quantification of IENF and sweat gland innervation density during ICU stay and at follow-up visit. Development of infection, sepsis and multiple organ failure was recorded throughout the ICU stay. RESULTS: Of the 14 patients recruited, 13 (93% had infections, sepsis or multiple organ failure. All had severe and non-length dependent loss of IENF. Sweat gland innervation was reduced in all except one patient. Of the 7 patients available for follow-up visit, three complained of diffuse sensory loss and burning pain, and another three showed clinical dysautonomia. CONCLUSIONS: Small fiber pathology can develop in the acute phase of critical illness and may explain chronic sensory impairment and pain in neurocritical care survivors. Its impact on long term disability warrants further studies involving also non-neurologic critical care patients.

  15. Percutaneous Intervention of Sequential Coronary Venous Graft

    OpenAIRE

    Zeki DOGAN; Karabulut, Ahmet; Uzunlar, Bulent

    2014-01-01

    We present a case with coronary bypass grafts in which venous graft was anastomosed to obtuse marginal (OM) 1 and OM2 branches sequentially. We performed percutaneous intervention to the proximal circumflex (CX), OM1, and bridging segment of the venous graft. Finally, bridging segment of the venous graft began to function as a CX body extending between the OM1 and OM2.

  16. Are Aortic Stent Grafts Safe in Pregnancy?

    OpenAIRE

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

    2015-01-01

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

  17. Trigeminal nerve schwannoma

    Directory of Open Access Journals (Sweden)

    Prashant Kashyap

    2016-05-01

    Full Text Available Trigeminal schwannomas are uncommon slow growing encapsulated tumours composed of schwann cells. Trigeminal schwannomas are the second most common type of schwannoma, after the far more common acoustic schwannoma. In this case definite diagnosis could not be made after 1 CT (computerized tomography scan and 3 MRI (magnetic resonance imaging (outside hospital but finally after proper clinical examination and discussion with radiologist about the best diagnostic imaging in this case we reached to a diagnosis of trigeminal nerve schwannoma after MRI brain with contrast. [Int J Res Med Sci 2016; 4(5.000: 1739-1741

  18. Treatment of complex internal carotid artery aneurysms using radial artery grafts. Surgical technique, perioperative complications, and results in 17 patients

    International Nuclear Information System (INIS)

    Complex giant or large internal carotid artery aneurysms present a surgical challenge because limitations and difficulty are encountered with either clipping or endovascular treatment. Our review of previous reports suggests that no current vascular assessment can accurately predict the occurrence of ischemic complications after internal carotid artery ligation. The present study concerns surgical technique, complications, and clinical outcome of radial artery grafting followed by parent artery trapping or proximal occlusion for management of these difficult lesions. Between September 1997 and October 2005, we performed radial artery grafting followed immediately by parent artery occlusion in 17 patients with giant or large complex intracranial carotid aneurysms (3 men, 14 women; mean follow-up duration, 62 months). All patients underwent postoperative digital subtraction angiography to assess graft patency and aneurysm obliteration. All 17 aneurysms were excluded from the cerebral circulation, with all radial artery grafts patent. Among 4 patients with cranial nerve disturbances, dysfunction was temporary in 5; in the others, oculomotor nerve paresis persisted. No perioperative cerebral infarction occurred. Sensory aphasia reflecting cerebral contusions caused by temporal lobe retraction resolved within 2 months, as did hemiparesis from a postoperative epidural hematoma. With appropriate attention to surgical technique, radial artery grafting followed by acute parent artery occlusion is a safe treatment for complex internal carotid artery aneurysms. Graft patency and aneurysm thrombosis were achieved in all patients. Cranial nerve dysfunction (III, VI) caused by altered blood flow from the internal carotid artery after occlusion was the most common complication and typically was temporary. In our experience with these difficult aneurysms, not only clipping but also reconstruction of the internal carotid artery was required, especially for wide-necked symptomatic

  19. An unusual ulnar nerve-median nerve communicating branch.

    OpenAIRE

    Hoogbergen, M M; Kauer, J M

    1992-01-01

    Branching of the ulnar nerve distal to the origin of the dorsal cutaneous branch was investigated in 25 hands in one of which an anatomical variation was observed. This finding may be of importance in the evaluation of certain entrapment phenomena of the ulnar nerve or unexplained sensory loss after trauma or surgical intervention in that particular area.

  20. Graft of the NT-3 persistent delivery gelatin sponge scaffold promotes axon regeneration, attenuates inflammation, and induces cell migration in rat and canine with spinal cord injury.

    Science.gov (United States)

    Li, Ge; Che, Ming-Tian; Zhang, Ke; Qin, Li-Na; Zhang, Yu-Ting; Chen, Rui-Qiang; Rong, Li-Min; Liu, Shu; Ding, Ying; Shen, Hui-Yong; Long, Si-Mei; Wu, Jin-Lang; Ling, Eng-Ang; Zeng, Yuan-Shan

    2016-03-01

    Persistent neurotrophic factor delivery is crucial to create a microenvironment for cell survival and nerve regeneration in spinal cord injury (SCI). This study aimed to develop a NT-3/fibroin coated gelatin sponge scaffold (NF-GS) as a novel controlled artificial release therapy for SCI. In vitro, bone marrow-derived mesenchymal stem cells (MSCs) were planted into the NF-GS and release test showed that NF-GS was capable to generate a sustainable NT-3 release up to 28 days. MSCs in NF-GS had high cell activity with excellent cell distribution and phenotype. Then, the NF-GS was transplanted into the injury site of spinal cord of rat and canine in vivo, which exhibited strong biocompatibility during post-transplantation period. Four weeks following transplantation, the concentration of NT-3 was much higher than that in control groups. Cavity areas in the injury/graft site were significantly reduced due to tissue regeneration and axonal extensions associated with myelin sheath through the glial scar into the NF-GS. Additionally, the NF-GS decreased the inflammation by reducing the CD68 positive cells and TNF-α. A striking feature was the occurrence of some cells and myelin-like structure that appeared to traverse the NF-GS. The present results demonstrate that the NF-GS has the property to control the release of NT-3 from the NT-3/fibroin complex thus facilitating regeneration of injured spinal cord. PMID:26774562

  1. Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

    Institute of Scientific and Technical Information of China (English)

    Yang Wang; Zheng-wei Li; Min Luo; Ya-jun Li; Ke-qiang Zhang

    2015-01-01

    polylactic glycolic acid conduit+bone marrow mesenchymal stem cells+extracellular matrix gel grafts than with the polylactic glycolic acid conduit+bone marrow mes-enchymal stem cells grafts and the autologous nerve grafts.

  2. Radiation grafting of synthetic fibres

    International Nuclear Information System (INIS)

    The dose-response relationships were studied in radiation-induced grafting copolymerization. Polyester textile fabric samples were irradiated with electrons from a Van de Graaff type accelerator under nitrogen atmosphere. Radiation doses ranged within 10 and 150 kGy. An 80% acrylic acid solution was used as the monomer while a 0.1% Mohr's salt solution was used as the inhibitor of acrylic acid homopolymerization. Grafting proceeded at 95 degC in a time interval of 10 mins. It was found that at constant time and temperature conditions the initially grafting grade rapidly increased while at values exceeding 20% only relatively small changes were recorded. The grafting grade was also found to favourably alter some properties of the modified materials, such as moisture content and tensile strength. (Z.M.)

  3. Artificial Hair Cells for Sensing Flows

    Science.gov (United States)

    Chen, Jack

    2007-01-01

    The purpose of this article is to present additional information about the flow-velocity sensors described briefly in the immediately preceding article. As noted therein, these sensors can be characterized as artificial hair cells that implement an approximation of the sensory principle of flow-sensing cilia of fish: A cilium is bent by an amount proportional to the flow to which it is exposed. A nerve cell at the base of the cilium senses the flow by sensing the bending of the cilium. In an artificial hair cell, the artificial cilium is a microscopic cantilever beam, and the bending of an artificial cilium is measured by means of a strain gauge at its base (see Figure 1). Figure 2 presents cross sections of a representative sensor of this type at two different stages of its fabrication process. The process consists of relatively- low-temperature metallization, polymer-deposition, microfabrication, and surface-micromachining subprocesses, including plastic-deformation magnetic assembly (PDMA), which is described below. These subprocesses are suitable for a variety of substrate materials, including silicon, some glasses, and some polymers. Moreover, because it incorporates a polymeric supporting structure, this sensor is more robust, relative to its silicon-based counterparts.

  4. Reconstruction of a Severely Crushed Leg with Interpositional Vessel Grafts and Latissimus Dorsi Flap

    Directory of Open Access Journals (Sweden)

    Chan Woo Park

    2012-07-01

    Full Text Available We present a case of a near total amputation at the distal tibial level, in which the patientemphatically wanted to save the leg. The anterior and posterior tibial nerves were intact,indicating a high possibility of sensory recovery after revascularization. The patient had openfractures at the tibia and fibula, but no bone shortening was performed. The posterior tibialvessels were reconstructed with an interposition saphenous vein graft from the contralateralside and a usable anterior tibial artery graft from the undamaged ipsilateral distal portions.The skin and soft tissue defects were covered using a subatmospheric pressure system fordemarcating the wound, and a latissimus dorsi myocutaneous free flap for definite coverageof the wound. At 6 months after surgery, the patient was ambulatory without requiringadditional procedures. Replantation without bone shortening, with use of vessel grafts andtemporary coverage of the wound with subatmospheric pressure dressings before definitecoverage, can shorten recovery time.

  5. Sacral Fracture Nonunion Treated by Bone Grafting through a Posterior Approach

    Directory of Open Access Journals (Sweden)

    Sang Yang Lee

    2013-01-01

    Full Text Available Nonunion of a sacral fracture is a rare but serious clinical condition which can cause severe chronic pain, discomfort while sitting, and significant restriction of the level of activities. Fracture nonunions reportedly occur most often after nonoperative initial treatment or inappropriate operative treatment. We report a case of fracture nonunion of the sacrum and pubic rami that resulted from non-operative initial treatment, which was treated successfully using bone grafting through a posterior approach and CT-guided percutaneous iliosacral screw fixation combined with anterior external fixation. Although autologous bone grafting has been the gold standard for the treatment of pelvic fracture nonunions, little has been written describing the approach. We utilized a posterior approach for bone grafting, which could allow direct visualization of the nonunion site and preclude nerve root injury. By this procedure, we were able to obtain the healing of fracture nonunion, leading to pain relief and functional recovery.

  6. Isolated cranial nerve palsies in multiple sclerosis

    OpenAIRE

    Zadro, Ivana; Barun, Barbara; Habek, Mario; Brinar, Vesna V.

    1997-01-01

    During a 10 year period 24 patients with definite multiple sclerosis with isolated cranial nerve palsies were studied (third and fourth nerve: one patient each, sixth nerve: 12 patients, seventh nerve: three patients, eighth nerve: seven patients), in whom cranial nerve palsies were the presenting sign in 14 and the only clinical sign of an exacerbation in 10 patients. MRI was carried out in 20 patients and substantiated corresponding brainstem lesions in seven patients (...

  7. Fibrin glue repair leads to enhanced axonal elongation during early peripheral nerve regeneration in an in vivo mouse model

    Institute of Scientific and Technical Information of China (English)

    Georgios Koulaxouzidis; Gernot Reim; Christian Witzel

    2015-01-01

    Microsurgical suturing is the gold standard of nerve coaptation. Although literature on the usefulness of ifbrin glue as an alternative is becoming increasingly available, it remains contradic-tory. Furthermore, no data exist on how both repair methods might inlfuence the morphological aspects (arborization; branching) of early peripheral nerve regeneration. We used the sciatic nerve transplantation model in thy-1 yellow lfuorescent protein mice (YFP;n = 10). Pieces of nerve (1cm) were grafted from YFP-negative mice (n = 10) into those expressing YFP. We per-formed microsuture coaptations on one side and used ifbrin glue for repair on the contralateral side. Seven days after grafting, the regeneration distance, the percentage of regenerating and ar-borizing axons, the number of branches per axon, the coaptation failure rate, the gap size at the repair site and the time needed for surgical repair were all investigated. Fibrin glue repair resulted in regenerating axons travelling further into the distal nerve. It also increased the percentage of arborizing axons. No coaptation failure was detected. Gap sizes were comparable in both groups. Fibrin glue signiifcantly reduced surgical repair time. The increase in regeneration distance, even after the short period of time, is in line with the results of others that showed faster axonal regen-eration after ifbrin glue repair. The increase in arborizing axons could be another explanation for better functional and electrophysiological results after ifbrin glue repair. Fibrin glue nerve coap-tation seems to be a promising alternative to microsuture repair.

  8. Interventions in Infrainguinal Bypass Grafts

    International Nuclear Information System (INIS)

    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

  9. FAS grafted superhydrophobic ceramic membrane

    International Nuclear Information System (INIS)

    The hydrophobic properties of γ-Al2O3 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 Al2O3 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-Al2O3 membrane surface as well as the formed surface morphology.

  10. Ultrasound-Guided Peripheral Nerve Procedures.

    Science.gov (United States)

    Strakowski, Jeffrey A

    2016-08-01

    Ultrasound guidance allows real-time visualization of the needle in peripheral nerve procedures, improving accuracy and safety. Sonographic visualization of the peripheral nerve and surrounding anatomy can provide valuable information for diagnostic purposes and procedure enhancement. Common procedures discussed are the suprascapular nerve at the suprascapular notch, deep branch of the radial nerve at the supinator, median nerve at the pronator teres and carpal tunnel, lateral cutaneous nerve of the thigh, superficial fibular nerve at the leg, tibial nerve at the ankle, and interdigital neuroma. For each procedure, the indications, relevant anatomy, preprocedural scanning technique, and injection procedure itself are detailed. PMID:27468673

  11. In vivo characterization of regenerative peripheral nerve interface function

    Science.gov (United States)

    Ursu, Daniel C.; Urbanchek, Melanie G.; Nedic, Andrej; Cederna, Paul S.; Gillespie, R. Brent

    2016-04-01

    Objective. Regenerative peripheral nerve interfaces (RPNIs) are neurotized free autologous muscle grafts equipped with electrodes to record myoelectric signals for prosthesis control. Viability of rat RPNI constructs have been demonstrated using evoked responses. In vivo RPNI characterization is the next critical step for assessment as a control modality for prosthetic devices. Approach. Two RPNIs were created in each of two rats by grafting portions of free muscle to the ends of divided peripheral nerves (peroneal in the left and tibial in the right hind limb) and placing bipolar electrodes on the graft surface. After four months, we examined in vivo electromyographic signal activity and compared these signals to muscular electromyographic signals recorded from autologous muscles in two rats serving as controls. An additional group of two rats in which the autologous muscles were denervated served to quantify cross-talk in the electrode recordings. Recordings were made while rats walked on a treadmill and a motion capture system tracked the hind limbs. Amplitude and periodicity of signals relative to gait were quantified, correlation between electromyographic and motion recording were assessed, and a decoder was trained to predict joint motion. Main Results. Raw RPNI signals were active during walking, with amplitudes of 1 mVPP, and quiet during standing, with amplitudes less than 0.1 mVPP. RPNI signals were periodic and entrained with gait. A decoder predicted bilateral ankle motion with greater than 80% reliability. Control group signal activity agreed with literature. Denervated group signals remained quiescent throughout all evaluations. Significance. In vivo myoelectric RPNI activity encodes neural activation patterns associated with gait. Signal contamination from muscles adjacent to the RPNI is minimal, as demonstrated by the low amplitude signals obtained from the Denervated group. The periodicity and entrainment to gait of RPNI recordings suggests the

  12. Application of biological dural graft made by meninges from porkers

    Institute of Scientific and Technical Information of China (English)

    Peng Liu; Shengping Huang; Songtao Qi

    2007-01-01

    sections were observed. White blood cells in venous blood were counted before operation and execution, separately. The obtained data were statistically analyzed.MAIN OUTCOME MEASURES: ① Wound healing and recovery following implantation of dural graft.②The amount of white blood cells in venous blood from rabbits at each time point before operation and before execution. ③ Histological examination results of operative site.RESULTS: Sixteen experimental rabbits were involved in the final analysis. ① The experimental rabbits of each group had no local infection, effusion and abnormal appearance. They had good wound healing and were normal to access to food. ② There were no significant differences in amount of white blood cells in venous blood from experimental rabbits between at each time point after modeling and before operation (P >0.05). ③Pathological observation of operative site: At postoperative 3 days, local acute inflammation repair reaction appeared; At postoperative 2 weeks, chronic inflammatory reaction appeared, endodermis in artificial dural graft formed, and artificial dural graft and host dura mater healed; In postoperative 1 month,wound began to chronically recover; In postoperative 3 months, host blood capillary began to form in artificial dural graft based on chronic repair. In all the control sides, fibroplasia was found, and a few neutrophils were found at postoperative 2 weeks.CONCLUSION: Biological surgical patch has high stability and good histocompatibility. It can provide dural epithelial epithelium, effectively prevent against the conglutination of scalp tissue and brain tissue, and avoid the leakage of cerebrospinal fluid.

  13. Submillimeter Diameter Poly(Vinyl Alcohol) Vascular Graft Patency in Rabbit Model

    Science.gov (United States)

    Cutiongco, Marie F. A.; Kukumberg, Marek; Peneyra, Jonnathan L.; Yeo, Matthew S.; Yao, Jia Y.; Rufaihah, Abdul Jalil; Le Visage, Catherine; Ho, Jackie Pei; Yim, Evelyn K. F.

    2016-01-01

    Microvascular surgery is becoming a prevalent surgical practice. Replantation, hand reconstruction, orthopedic, and free tissue transfer procedures all rely on microvascular surgery for the repair of venous and arterial defects at the millimeter and submillimeter levels. Often, a vascular graft is required for the procedure as a means to bridge the gap between native arteries. While autologous vessels are desired for their bioactivity and non-thrombogenicity, the tedious harvest process, lack of availability, and caliber or mechanical mismatch contribute to graft failure. Thus, there is a need for an off-the-shelf artificial vascular graft that has low thrombogenic properties and mechanical properties matching those of submillimeter vessels. Poly(vinyl alcohol) hydrogel (PVA) has excellent prospects as a vascular graft due to its bioinertness, low thrombogenicity, high water content, and tunable mechanical properties. Here, we fabricated PVA grafts with submillimeter diameter and mechanical properties that closely approximated those of the rabbit femoral artery. In vitro platelet adhesion and microparticle release assay verified the low thrombogenicity of PVA. A stringent proof-of-concept in vivo test was performed by implanting PVA grafts in rabbit femoral artery with multilevel arterial occlusion. Laser Doppler measurements indicated the improved perfusion of the distal limb after implantation with PVA grafts. Moreover, ultrasound Doppler and angiography verified that the submillimeter diameter PVA vascular grafts remained patent for 2 weeks without the aid of anticoagulant or antithrombotics. Endothelial cells were observed in the luminal surface of one patent PVA graft. The advantageous non-thrombogenic and tunable mechanical properties of PVA that are retained even in the submillimeter diameter dimensions support the application of this biomaterial for vascular replacement in microvascular surgery. PMID:27376059

  14. Radiation grafting on natural films

    International Nuclear Information System (INIS)

    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

  15. Nanofibrous nerve conduits for repair of 30-mm-long sciatic nerve defects

    OpenAIRE

    Biazar, Esmaeil; Keshel, Saeed Heidari; Pouya, Majid; Rad, Hadi; Nava, Melody Omrani; Azarbakhsh, Mohammad; Hooshmand, Shirin

    2013-01-01

    It has been confirmed that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit can promote peripheral nerve regeneration in rats. However, its efficiency in repair of over 30-mm-long sciatic nerve defects needs to be assessed. In this study, we used a nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit to bridge a 30-mm-long gap in the rat sciatic nerve. At 4 months after nerve conduit implantation, regenerated nerves were cally observed and histologicall...

  16. Quo Vadis, Artificial Intelligence?

    OpenAIRE

    Alfons Schuster; Daniel Berrar; Naoyuki Sato

    2010-01-01

    Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervou...

  17. Anticipatory Artificial Autopoiesis

    OpenAIRE

    DuBois, Daniel; Holmberg, Stig C.

    2010-01-01

    In examining relationships between autopoiesis and anticipation in artificial life (Alife) systems it is demonstrated that anticipation may increase efficiency and viability in artificial autopoietic living systems. This paper, firstly, gives a review of the Varela et al [1974] automata algorithm of an autopoietic living cell. Some problems in this algorithm must be corrected. Secondly, a new and original anticipatory artificial autopoiesis algorithm for automata is presented. ...

  18. Artificial cognition architectures

    CERN Document Server

    Crowder, James A; Friess, Shelli A

    2013-01-01

    The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

  19. Doped Colloidal Artificial Ice

    OpenAIRE

    Libal, A.; Reichhardt, C. J. Olson; Reichhardt, C.

    2015-01-01

    We examine square and kagome artificial spin ice for colloids confined in arrays of double-well traps. Unlike magnetic artificial spin ices, colloidal and vortex artificial spin ice realizations allow creation of doping sites through double occupation of individual traps. We find that doping square and kagome ice geometries produces opposite effects. For square ice, doping creates local excitations in the ground state configuration that produce a local melting effect as the temperature is rai...

  20. Inteligencia artificial en vehiculo

    OpenAIRE

    Amador Díaz, Pedro

    2012-01-01

    Desarrollo de un robot seguidor de líneas, en el que se implementan diversas soluciones de las áreas de sistemas embebidos e inteligencia artificial. Desenvolupament d'un robot seguidor de línies, en el qual s'implementen diverses solucions de les àrees de sistemes encastats i intel·ligència artificial. Follower robot development of lines, in which various solutions are implemented in the areas of artificial intelligence embedded systems.

  1. Enzyme-functionalized vascular grafts catalyze in-situ release of nitric oxide from exogenous NO prodrug.

    Science.gov (United States)

    Wang, Zhihong; Lu, Yaxin; Qin, Kang; Wu, Yifan; Tian, Yingping; Wang, Jianing; Zhang, Jimin; Hou, Jingli; Cui, Yun; Wang, Kai; Shen, Jie; Xu, Qingbo; Kong, Deling; Zhao, Qiang

    2015-07-28

    Nitric oxide (NO) is an important signaling molecule in cardiovascular system, and the sustained release of NO by endothelial cells plays a vital role in maintaining patency and homeostasis. In contrast, lack of endogenous NO in artificial blood vessel is believed to be the main cause of thrombus formation. In this study, enzyme prodrug therapy (EPT) technique was employed to construct a functional vascular graft by immobilization of galactosidase on the graft surface. The enzyme-functionalized grafts exhibited excellent catalytic property in decomposition of the exogenously administrated NO prodrug. Localized and on-demand release of NO was demonstrated by in vitro release assay and fluorescent probe tracing in an ex vivo model. The immobilized enzyme retained catalytic property even after subcutaneous implantation of the grafts for one month. The functional vascular grafts were implanted into the rat abdominal aorta with a 1-month monitoring period. Results showed effective inhibition of thrombus formation in vivo and enhancement of vascular tissue regeneration and remodeling on the grafts. Thus, we create an enzyme-functionalized vascular graft that can catalyze prodrug to release NO locally and sustainably, indicating that this approach may be useful to develop new cell-free vascular grafts for treatment of vascular diseases. PMID:26004323

  2. Schwannomatosis of the sciatic nerve

    International Nuclear Information System (INIS)

    A 52-year-old woman with schwannomatosis in the left sciatic nerve is presented. The patient had no stigmata of neurofibromatosis (NF) type 1 or 2. Cutaneous or spinal schwannomas were not detected. Magnetic resonance (MR) imaging of the sciatic nerve revealed more than 15 tumors along the course of the nerve. Histological examination revealed schwannomas consisting of Antoni A and B areas. Immunohistochemical study showed most cells reacting intensely for S-100 protein. The patient underwent conservative follow-up treatment due to the minimal symptoms. The relationship of the disease with NF-2 and plexiform schwannoma is discussed. (orig.)

  3. Schwannomatosis of the sciatic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Tetsuji; Maruyama, Shigeki; Mizuno, Kosaku [Dept. of Orthopaedic Surgery, Kobe University School of Medicine (Japan)

    2001-02-01

    A 52-year-old woman with schwannomatosis in the left sciatic nerve is presented. The patient had no stigmata of neurofibromatosis (NF) type 1 or 2. Cutaneous or spinal schwannomas were not detected. Magnetic resonance (MR) imaging of the sciatic nerve revealed more than 15 tumors along the course of the nerve. Histological examination revealed schwannomas consisting of Antoni A and B areas. Immunohistochemical study showed most cells reacting intensely for S-100 protein. The patient underwent conservative follow-up treatment due to the minimal symptoms. The relationship of the disease with NF-2 and plexiform schwannoma is discussed. (orig.)

  4. Nerve Transfers for Treatment of Isolated Axillary Nerve Injuries

    OpenAIRE

    Wheelock, Margie; Clark, Tod A; Giuffre, Jennifer L

    2015-01-01

    Almost one-half of all dislocations involve the shoulder and may also involve the axillary nerves, which may influence functional recovery and result in persistent shoulder neuropathy. Although individuals with intact rotator cuffs may be able to compensate for axillary nerve dysfunction, the injury may become problematic in later years, especially given the increasing incidence of rotator cuff tears in aging populations, thus placing increased importance on the immediate success of acute man...

  5. Materials testing and requirements for the ERDA nuclear-powered artificial heart. Technical progress report, July 15, 1974--May 1, 1975

    International Nuclear Information System (INIS)

    Progress on the materials research and development effort for the ERDA-sponsored nuclear-powered artificial heart program is presented. Progress made during the first three years on hydrogel grafting and biological studies is summarized. Progress during the fourth year on studies of implanted artificial hearts, development of albumin surfaces, and in vitro mechanical studies is presented. (U.S.)

  6. Plant grafting: new mechanisms, evolutionary implications.

    Science.gov (United States)

    Goldschmidt, Eliezer E

    2014-01-01

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

  7. Plant grafting: new mechanisms, evolutionary implications

    Directory of Open Access Journals (Sweden)

    Eliezer E Goldschmidt

    2014-12-01

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

  8. Artificial life and life artificialization in Tron

    Directory of Open Access Journals (Sweden)

    Carolina Dantas Figueiredo

    2012-12-01

    Full Text Available Cinema constantly shows the struggle between the men and artificial intelligences. Fiction, and more specifically fiction films, lends itself to explore possibilities asking “what if?”. “What if”, in this case, is related to the eventual rebellion of artificial intelligences, theme explored in the movies Tron (1982 and Tron Legacy (2010 trat portray the conflict between programs and users. The present paper examines these films, observing particularly the possibility programs empowering. Finally, is briefly mentioned the concept of cyborg as a possibility of response to human concerns.

  9. Imaging of the facial nerve.

    Science.gov (United States)

    Veillona, F; Ramos-Taboada, L; Abu-Eid, M; Charpiot, A; Riehm, S

    2010-05-01

    The facial nerve is responsible for the motor innervation of the face. It has a visceral motor function (lacrimal, submandibular, sublingual glands and secretion of the nose); it conveys a great part of the taste fibers, participates to the general sensory of the auricle (skin of the concha) and the wall of the external auditory meatus. The facial mimic, production of tears, nasal flow and salivation all depend on the facial nerve. In order to image the facial nerve it is mandatory to be knowledgeable about its normal anatomy including the course of its efferent and afferent fibers and about relevant technical considerations regarding CT and MR to be able to achieve high-resolution images of the nerve. PMID:20456888

  10. Imaging of the facial nerve

    International Nuclear Information System (INIS)

    The facial nerve is responsible for the motor innervation of the face. It has a visceral motor function (lacrimal, submandibular, sublingual glands and secretion of the nose); it conveys a great part of the taste fibers, participates to the general sensory of the auricle (skin of the concha) and the wall of the external auditory meatus. The facial mimic, production of tears, nasal flow and salivation all depend on the facial nerve. In order to image the facial nerve it is mandatory to be knowledgeable about its normal anatomy including the course of its efferent and afferent fibers and about relevant technical considerations regarding CT and MR to be able to achieve high-resolution images of the nerve.

  11. Imaging of the facial nerve

    Energy Technology Data Exchange (ETDEWEB)

    Veillon, F. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France)], E-mail: Francis.Veillon@chru-strasbourg.fr; Ramos-Taboada, L.; Abu-Eid, M. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France); Charpiot, A. [Service d' ORL, Hopital de Hautepierre, 67098 Strasbourg Cedex (France); Riehm, S. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France)

    2010-05-15

    The facial nerve is responsible for the motor innervation of the face. It has a visceral motor function (lacrimal, submandibular, sublingual glands and secretion of the nose); it conveys a great part of the taste fibers, participates to the general sensory of the auricle (skin of the concha) and the wall of the external auditory meatus. The facial mimic, production of tears, nasal flow and salivation all depend on the facial nerve. In order to image the facial nerve it is mandatory to be knowledgeable about its normal anatomy including the course of its efferent and afferent fibers and about relevant technical considerations regarding CT and MR to be able to achieve high-resolution images of the nerve.

  12. GRP nerves in pig antrum

    DEFF Research Database (Denmark)

    Holst, J J; Poulsen, Steen Seier

    We extracted gastrin-releasing peptide (GRP) and its C-terminal decapeptide corresponding to 6.4 and 6.8 pmol/g from pig antrum mucosa. By immunohistochemistry GRP was localized to mucosal, submucosal, and myenteric nerve fibers. A few nerve cell bodies were also identified. Using isolated perfused...... pig antrum with intact vagal innervation, we found concomitant, atropine-resistant release of GRP and gastrin during electrical stimulation of the vagal nerves. Intra-arterial GRP at 10(-11)-10(-10) mol/l caused up to fivefold, dose-dependent increases in gastrin secretion; higher doses were less...... response to GRP and abolished the effect of vagal stimulation. The available evidence strongly suggests that GRP nerves are responsible for the stimulatory vagal effects on gastrin secretion in the pig....

  13. Nerve Disease and Bladder Control

    Science.gov (United States)

    ... Research Training & Career Development Grant programs for students, postdocs, and faculty Research at NIDDK Labs, faculty, and ... KB) Alternate Language URL Nerve Disease and Bladder Control Page Content On this page: What bladder control ...

  14. Overview of Optic Nerve Disorders

    Science.gov (United States)

    ... 2 Diabetes, Heart Disease a Dangerous Combo Are 'Workaholics' Prone to OCD, Anxiety? ALL NEWS > Resources First ... anatomic arrangement, damage along the optic nerve pathway causes specific patterns of vision loss. By understanding the ...

  15. Vascularized osseous graft for scaphoid

    International Nuclear Information System (INIS)

    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

  16. Study of using nerve conduits containing with nerve fragments to repair rat′s peripheral nerve defect%神经导管结合神经片段修复外周神经损伤

    Institute of Scientific and Technical Information of China (English)

    杨华清; 张志军; 王建华; 敖强; 王世杰; 刘强

    2011-01-01

    Objective To study the effect of using nerve conduits containing with nerve fragments to repair rat' s peripheral nerve defect, and to provide theory foundation and experiment experience for further study on repair and regeneration of peripheral nerve defect. Methods 24 Wistar rats with 10 mm sciatic nerve defect of the right lower extremity were divided into three groups : the nerve defects of group A were repaired with autochthonous graft , group B with nerve conduits containing of nerve fragments and group C with nerve conduits only. Morphology and functional rehabilitation were observed and electrophysiology tests of rats were performed. Results The results of walking track analysis; SFI; - 81.20 ± 2.81, electrophysiology tests [ NCV:( 28. 93 ± 5. 07 ) m/s, AMP: ( 5. 46 ± 2. 76 ) mv ] and histology test of regeneration nerves [ myelinization density ;3953 ±468/HP,myelin sheath area : (2. 77 ±0. 83 ) [Am] on rats in group B were significantly better than those in group C ( P 0. 05 ). Conclusions The effect of using nerve conduits containing nerve fragments is better than using nerve conduits only, especially for neurite regeneration and functional rehabilitation , although the effect may not be as well as autochthonous graft.%目的 研究神经片段结合神经导管治疗外周神经缺损,为周围神经损伤修复与重建的解决途径提供实验依据.方法 24 只成年Wistar 大鼠随机分为A、B、C 组,分别为神经自体移植、与含有神经片段的神经导管和单纯导管移植桥接大鼠10 mm 神经缺损,各组间在形态学、电生理、组织学进行比较.结果 B 组大鼠移植侧肢体足迹实验的坐骨神经功能指数(SFI)为-81.20 ±2.81,神经干传导速度为(28.93 ±5.07)m/s、动作电位的振幅为(5.46 ±2.76)mV,再生神经中段检查髓鞘化轴突密度为(3953 ±468)/视野,髓鞘面积为(2.77 ±0.83)μm,与C 组比较差异有统计学意义(P <0.05).结论 含有神经片段的神经导管组织

  17. Artificial insemination in poultry

    Science.gov (United States)

    Artificial insemination is a relative simple yet powerful tool geneticists can employ for the propagation of economically important traits in livestock and poultry. In this chapter, we address the fundamental methods of the artificial insemination of poultry, including semen collection, semen evalu...

  18. Cranial nerve palsies in childhood

    OpenAIRE

    Lyons, C J; Godoy, F; ALQahtani, E

    2015-01-01

    We review ocular motor cranial nerve palsies in childhood and highlight many of the features that differentiate these from their occurrence in adulthood. The clinical characteristics of cranial nerve palsies in childhood are affected by the child's impressive ability to repair and regenerate after injury. Thus, aberrant regeneration is very common after congenital III palsy; Duane syndrome, the result of early repair after congenital VI palsy, is invariably associated with retraction of the g...

  19. Types of Coronary Artery Bypass Grafting

    Science.gov (United States)

    ... best option for you based on your needs. Traditional Coronary Artery Bypass Grafting Traditional CABG is used when at least one major ... Grafting This type of CABG is similar to traditional CABG because the chest bone is opened to ...

  20. CT appearance of intercostal nerve neurotisation

    OpenAIRE

    Gadahadh, R; Rachapalli, V; Roberts, D. E.

    2012-01-01

    A nerve transfer or neurotisation procedure is performed to repair damaged nerves, in particular those of the brachial plexus following an avulsion injury. An intercostal to phrenic nerve transfer to re-innervate the diaphragm in patients with high cervical spine injury has also been reported in the literature. We present the imaging finding in a 65-year-old female who had an intercostal nerve transfer for a damaged phrenic nerve following a resection for a non-small cell lung carcinoma.

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

    DEFF Research Database (Denmark)

    Gao, H; Sandermann, J; Prag, J; Lund, L; Lindholt, Jes S.

    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....

  2. Unilateral traumatic oculomotor nerve paralysis

    International Nuclear Information System (INIS)

    The present authors report a case of unilateral traumatic oculomotor nerve paralysis which shows interesting CT findings which suggest its mechanism. A 60-year-old woman was admitted to our hospital with a cerebral concussion soon after a traffic accident. A CT scan was performed soon after admission. A high-density spot was noted at the medial aspect of the left cerebral peduncle, where the oculomotor nerve emerged from the midbrain, and an irregular, slender, high-density area was delineated in the right dorsolateral surface of the midbrain. Although the right hemiparesis had already improved by the next morning, the function of the left oculomotor nerve has been completely disturbed for the three months since the injury. In our case, it is speculated that an avulsion of the left oculomotor nerve rootlet occurred at the time of impact as the mechanism of the oculomotor nerve paralysis. A CT taken soon after the head injury showed a high-density spot; this was considered to be a hemorrhage occurring because of the avulsion of the nerve rootlet at the medial surface of the cerebral peduncle. (J.P.N.)

  3. The absence of CD47 promotes nerve fiber growth from cultured ventral mesencephalic dopamine neurons.

    Directory of Open Access Journals (Sweden)

    Franziska Marschinke

    Full Text Available In ventral mesencephalic organotypic tissue cultures, two timely separated sequences of nerve fiber growth have been observed. The first appearing nerve fiber pattern is a long-distance outgrowth that occurs before astrocytes start to proliferate and migrate to form an astrocytic monolayer that finally surrounds the tissue slice. These long-distance growing nerve fibers are retracted as the astrocytes migrate, and are followed by a secondary outgrowth. The secondary outgrowth is persistent in time but reaches short distances, comparable with outgrowth seen from a dopaminergic graft implanted to the brain. The present study was focused on the interaction between the astrocytes and the long-distance growing non-glial associated nerve fibers. Cross talk between astroglia and neurite formation might occur through the integrin-associated protein CD47. CD47 serves as a ligand for signal regulatory protein (SIRP α and as a receptor for the extracellular matrix protein thrombospondin-1 (TSP-1. Embryonic day 14 ventral mesencephalic tissue from CD47(+/+ and CD47(-/- mice was used to investigate astrocytic migration and the tyrosine hydroxylase (TH -positive outgrowth that occurred remote from the astrocytes. TH-immunohistochemistry demonstrated that the non-glial-associated nerve fiber outgrowth in CD47(-/- cultures reached significantly longer distances and higher density compared to nerve fibers formed in CD47(+/+ cultures at 14 days in vitro. These nerve fibers often had a dotted appearance in CD47(+/+ cultures. No difference in the astrocytic migration was observed. Further investigations revealed that the presence of CD47 in control culture did neither hamper non-glial-associated growth through SIRPα nor through TSP-1 since similar outgrowth was found in SIRPα mutant cultures and in CD47(+/+ cultures treated with blocking antibodies against the TSP-1, respectively, as in the control cultures. In conclusion, long-distance growing nerve fiber

  4. Plant grafting: new mechanisms, evolutionary implications

    OpenAIRE

    Goldschmidt, Eliezer E.

    2014-01-01

    Grafting, an old plant propagation practice, is still widely used with fruit trees and in recent decades also with vegetables. Taxonomic proximity is a general prerequisite for successful graft-take and long-term survival of the grafted, composite plant. However, the mechanisms underlying interspecific graft incompatibility are as yet insufficiently understood. Hormonal signals, auxin in particular, are believed to play an important role in the wound healing and vascular regeneration within t...

  5. Distribution of the degrees of grafting in graft polymers

    Czech Academy of Sciences Publication Activity Database

    Netopilík, Miloš; Janata, Miroslav; Kratochvíl, Pavel

    Gargnano : EPF , 2010. s. 58. [EUPOC 2010 - Europolymer Conference, Hierarchically Structured Polymers. 30.05.2010-04.06.2010, Gargnano] R&D Projects: GA AV ČR IAA400500703 Institutional research plan: CEZ:AV0Z40500505 Keywords : grafting * molecular weight distribution Subject RIV: CD - Macromolecular Chemistry

  6. Use of porous high-density polyethylene grafts in open rhinoplasty: no infectious complication seen in spreader and dorsal grafts

    OpenAIRE

    Mohammadi, Shabahang; Mohseni, Mohammad; Eslami, Masoumeh; Arabzadeh, Hessein; Eslami, Morteza

    2014-01-01

    Objective The aim of this study is to use porous high-density polyethylene grafts (Medpor) in open rhinoplasty and then assess complication rate and aesthetic outcomes. Methods In a prospective cohort study, we performed open rhinoplasty and employed Medpor as rhinoplasty grafts. Then we compared their complication rate. Results In a total of 64 patients, 84 Medpor grafts -38 dorsal grafts, 23 strut grafts, 8 rim grafts, 5 button grafts and 10 spreader grafts – were utilized. Moreover, 5septa...

  7. Multimodality imaging of coronary artery bypass grafts

    OpenAIRE

    Salm, Liesbeth Pauline

    2006-01-01

    This thesis describes multiple imaging modalities to examine coronary artery bypass grafts, and the research which was performed to further develop noninvasive imaging techniques to detect stenoses in native coronary arteries and bypass grafts in patients who experienced recurrent chest pain after coronary artery bypass grafting (CABG).

  8. Electrophysiological evaluation of nerve function in inferior alveolar nerve injury: relationship between nerve action potentials and histomorphometric observations.

    Science.gov (United States)

    Murayama, M; Sasaki, K; Shibahara, T

    2015-12-01

    The objective of this study was to improve the accuracy of diagnosis of inferior alveolar nerve (IAN) injury by determining degrees of nerve disturbance using the sensory nerve action potential (SNAP) and sensory nerve conduction velocity (SCV). Crush and partial and complete nerve amputation injuries were applied to the IAN of rabbits, then SNAPs and histomorphometric observations were recorded at 1, 5, and 10 weeks. For crush injury, most nerves were smaller in diameter at 5 weeks than at 1 week, however after 10 weeks, extensive nerve regeneration was observed. The SNAP showed a decrease in SCV at weeks 1 and 5, followed by an increase at week 10. For partial nerve amputation, small to medium-sized nerve fibres were observed at weeks 1 and 5, then larger nerves were seen at week 10. Minimal changes in SCV were observed at weeks 1 and 5, however SCV increased at week 10. For complete nerve amputation, nerve fibres were sparse at week 1, but gradual nerve regeneration was observed at weeks 5 and 10. SNAPs were detectable from week 10, however the SCV was extremely low. This study showed SCV to be an effective factor in the evaluation of nerve injury and regeneration. PMID:26433750

  9. STUDY OF GRAFT SITES IN EPOXY GRAFT COPOLYMERS BY QUANTUM CHEMISTRY CALCULATIONS

    Institute of Scientific and Technical Information of China (English)

    Song Chen; Xiao-yu Li

    2009-01-01

    Exploration and characterization of grafting productions by experimental methods are often cumbersome or sometimes impossible. Therefore, quantum chemistry calculations were performed to characterize the graft sites of epoxy resin. According to the Gibbs free energy criterion of the second law of thermodynamic, the reported graft sites were confirmed, and more important, some unreported graft sites were found. In addition, method of increasing the number of graft sites was studied in this article.

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

    Science.gov (United States)

    Suma, Hisayoshi

    2016-01-01

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

  11. The longitudinal epineural incision and complete nerve transection method for modeling sciatic nerve injury

    OpenAIRE

    Xing-long Cheng; Pei Wang; Bo Sun; Shi-bo Liu; Yun-feng Gao; Xin-ze He; Chang-yu Yu

    2015-01-01

    Injury severity, operative technique and nerve regeneration are important factors to consider when constructing a model of peripheral nerve injury. Here, we present a novel peripheral nerve injury model and compare it with the complete sciatic nerve transection method. In the experimental group, under a microscope, a 3-mm longitudinal incision was made in the epineurium of the sciatic nerve to reveal the nerve fibers, which were then transected. The small, longitudinal incision in the epineur...

  12. A simple model of radial nerve injury in the rhesus monkey to evaluate peripheral nerve repair

    OpenAIRE

    Wang, Dong; Huang, Xijun; Fu, Guo; Gu, Liqiang; Liu, Xiaolin; WANG, HONGGANG; Hu, Jun; Yi, Jianhua; Niu, Xiaofeng; Zhu, Qingtang

    2014-01-01

    Current research on bone marrow stem cell transplantation and autologous or xenogenic nerve transplantation for peripheral nerve regeneration has mainly focused on the repair of peripheral nerve defects in rodents. In this study, we established a standardized experimental model of radial nerve defects in primates and evaluated the effect of repair on peripheral nerve injury. We repaired 2.5-cm lesions in the radial nerve of rhesus monkeys by transplantation of autografts, acellular allografts...

  13. Markers of primary graft dysfunction

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to methods for diagnosing transplant rejection, or a condition associated with transplant rejection, such as, primary graft dysfunction in a subject, to antigen probe arrays for performing such a diagnosis, and to antigen probe sets for generating such arrays....

  14. Polyether-polyester graft copolymer

    Science.gov (United States)

    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.

  15. Impulsive Neural Networks Algorithm Based on the Artificial Genome Model

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2014-05-01

    Full Text Available To describe gene regulatory networks, this article takes the framework of the artificial genome model and proposes impulsive neural networks algorithm based on the artificial genome model. Firstly, the gene expression and the cell division tree are applied to generate spiking neurons with specific attributes, neural network structure, connection weights and specific learning rules of each neuron. Next, the gene segment duplications and divergence model are applied to design the evolutionary algorithm of impulsive neural networks at the level of the artificial genome. The dynamic changes of developmental gene regulatory networks are controlled during the whole evolutionary process. Finally, the behavior of collecting food for autonomous intelligent agent is simulated, which is driven by nerves. Experimental results demonstrate that the algorithm in this article has the evolutionary ability on large-scale impulsive neural networks

  16. Graft-copolymer-based approach to clear, durable, and anti-smudge polyurethane coatings.

    Science.gov (United States)

    Rabnawaz, Muhammad; Liu, Guojun

    2015-05-26

    Clear anti-smudge coatings with a thickness of up to tens of micrometers have been prepared through a graft-copolymer-based approach from commercial precursors. The coatings repel water, diiodomethane, hexadecane, ink, and an artificial fingerprint liquid. In addition, they can be readily applied onto different substrates using different coating methods. These coatings could find applications in protecting hand-held electronic devices from fingerprints, windows from stains, and buildings from graffiti. PMID:25919762

  17. Silicone Molding and Lifetime Testing of Peripheral Nerve Interfaces for Neuroprostheses

    Energy Technology Data Exchange (ETDEWEB)

    Gupte, Kimaya [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Biomedical Engineering; Tolosa, Vanessa [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Center for Micro- and Nanotechnology

    2016-08-10

    Implantable peripheral nerve cuffs have a large application in neuroprostheses as they can be used to restore sensation to those with upper limb amputations. Modern day prosthetics, while lessening the pain associated with phantom limb syndrome, have limited fine motor control and do not provide sensory feedback to patients. Sensory feedback with prosthetics requires communication between the nervous system and limbs, and is still a challenge to accomplish with amputees. Establishing this communication between the peripheral nerves in the arm and artificial limbs is vital as prosthetics research aims to provide sensory feedback to amputees. Peripheral nerve cuffs restore sensation by electrically stimulating certain parts of the nerve in order to create feeling in the hand. Cuff electrodes have an advantage over standard electrodes as they have high selective stimulation by bringing the electrical interface close to the neural tissue in order to selectively activate targeted regions of a peripheral nerve. In order to further improve the selective stimulation of these nerve cuffs, there is need for finer spatial resolution among electrodes. One method to achieve a higher spatial resolution is to increase the electrode density on the cuff itself. Microfabrication techniques can be used to achieve this higher electrode density. Using L-Edit, a layout editor, microfabricated peripheral nerve cuffs were designed with a higher electrode density than the current model. This increase in electrode density translates to an increase in spatial resolution by at least one order of magnitude. Microfabricated devices also have two separate components that are necessary to understand before implantation: lifetime of the device and assembly to prevent nerve damage. Silicone molding procedures were optimized so that devices do not damage nerves in vivo, and lifetime testing was performed on test microfabricated devices to determine their lifetime in vivo. Future work of this project

  18. Artificial ecosystem selection.

    Science.gov (United States)

    Swenson, W; Wilson, D S; Elias, R

    2000-08-01

    Artificial selection has been practiced for centuries to shape the properties of individual organisms, providing Darwin with a powerful argument for his theory of natural selection. We show that the properties of whole ecosystems can also be shaped by artificial selection procedures. Ecosystems initiated in the laboratory vary phenotypically and a proportion of the variation is heritable, despite the fact that the ecosystems initially are composed of thousands of species and millions of individuals. Artificial ecosystem selection can be used for practical purposes, illustrates an important role for complex interactions in evolution, and challenges a widespread belief that selection is most effective at lower levels of the biological hierarchy. PMID:10890915

  19. Synthesis and characterization of macromolecular layers grafted to polymer surfaces

    Science.gov (United States)

    Burtovyy, Oleksandr

    membranes modified with a reactive anchoring layer can be successfully used to build membrane assemblies by incorporating silica, aluminum, or titanium oxide microparticles as spacers. It is expected that the proposed approaches for the surface modification of the membranes and for the generation of multilayered membrane assemblies can be employed straightforwardly to provide an efficient platform for fabrication of breathable protective materials. Characterization of modified membranes with a cantilever-based method, which can be used for prediction of properties and behavior of thin grafted films, is reported. This technique can be used as a method for fast screening of modified membranes. The method is very robust and capable of detecting very small quantities of substance adsorbed; kinetics of the process can be tracked, as well. This approach can be further developed as a handheld sensor for early warning of the presence of chemical vapors and nerve agents.

  20. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects

    Institute of Scientific and Technical Information of China (English)

    Huawei Liu; Weisheng Wen; Min Hu; Wenting Bi; Lijie Chen; Sanxia Liu; Peng Chen; Xinying Tan

    2013-01-01

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as wel as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. Electro-physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation il ustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits com-bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits.

  1. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects.

    Science.gov (United States)

    Liu, Huawei; Wen, Weisheng; Hu, Min; Bi, Wenting; Chen, Lijie; Liu, Sanxia; Chen, Peng; Tan, Xinying

    2013-11-25

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation illustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits. PMID:25206635

  2. Vascular grafting strategies in coronary intervention

    Science.gov (United States)

    Knight, Darryl; Gillies, Elizabeth; Mequanint, Kibret

    2014-06-01

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

  3. Transpedicle bone graft after bracing repeatedly for treating severe thoracic and lumbar vertebral burst fractures%多次撑开植骨治疗严重胸腰椎爆裂骨折

    Institute of Scientific and Technical Information of China (English)

    周兆文; 普有登; 尹劲; 袁晓峰; 胡军; 贺云; 段洪

    2013-01-01

    Objective To research the better surgical strategy for severe thoracic and lumbar vertebral burst fracture.To consummate the evaluation methods in operation and technic ofpedicle screw internal fixation combined with transpedicle graft of artificial bone.Methods From August 2007 to March 2013,44 severe cases (compression ratio of vertebral margins > 50%,or encrochment ratio in vertebral canal > 50%) of thoracic and lumbar vertebral burst fractures were cured through the operation of posterior pedicle screw internal fixation combined with transpedicle graft of artificial bone.All cases were braced repeatedly 2~4 times and 6~8cm3 were embedded into the wound vertebral body."One-line sign" or "antrorse arc line sign" of the posterior border of the burst vertebral body and the dgree of compression of the vertebral canal can be oberved clearly on lateral fluoroscopy in the operation.Results The height and configuration of vertebral body restored to 96%~105% and compression ratio of posterior vertebral margins remained 0~6% only.Symptom of nerve injury were not found out.After follow-up of 1~24 months,breakdown of screws and rods,kyphosis,nerve injury were not found out.Conclusion Partial severe lumbar burst fractures can be cured through the operation of posterior pedicle screw internal fixation and bracing several times combined with transpedicle graft of artificial bone.%目的 探讨严重胸腰椎爆裂骨折后路手术更好的复位方法,并规范术中观察方法和经伤椎椎弓根植骨技术.方法 44例胸腰椎严重爆裂骨折(椎管占位>50%或伴高度塌陷>50%)均采用脊柱后路钉棒系统多次撑开方法复位固定,并经椎弓根行伤椎体内打压植骨治疗.术中反复撑开2~4次,植人工骨6~8cm3;术中C臂透视,清楚观察椎体后缘“直线”或“前弧线”恢复情况,借此准确判断椎管占位程度.结果 X线和CT显示骨折复位满意,椎体前后缘高度恢复至96

  4. Shortening of the development cycle in winter rape (Brassica napus var. oleifera L. by grafting nonvernalized scions on generative stock

    Directory of Open Access Journals (Sweden)

    Franciszek Dubert

    2013-12-01

    Full Text Available The conditions were investigated under which the development cycle in winter rape could be markedly reduced by grafting. Scions from non vernalized seedlings were grafted onto stock plants beginning their generative phase. Winter rape plants vernalized under natural field conditions and spring rape plants in the initial generative phase were used as stock. Best results were obtained by grafting scions from plants at the stage of 4 leaves, i.e. after 3 weeks of growth, onto winter rape stock. With such scions the effectiveness of graftings was high and seed crops were obtained 170 days earlier than under natural field conditions of growth and 80 days earlier than under artificial conditions. Scions grafted onto winter rape stock produced more siliques than those on spring rape. Grafting of scions after cutting off their apical meristems allowed formation of side shoots and consequently resulted in higher yields of siliques; the formation of siliques, however, was delayed by about 10 days as compared to grafts with apical meristems.

  5. Modified and Grafted Coronectomy: A New Technique and a Case Report with Two-Year Followup

    Directory of Open Access Journals (Sweden)

    Michael Leizerovitz

    2013-01-01

    Full Text Available Purpose. A standard coronectomy (intentional partial odontectomy is recommended for mandibular third molar (MTM extraction cases with a high risk of inferior alveolar nerve injury (IANI. However, complications such as inadvertent intraoperative root removal, post-op root migration, second molar (MSM periodontal defects and others do exist. This report presents a new technique, the Modified and Grafted Coronectomy (MGC, describes the measures to prevent or minimize the known drawbacks of the standard coronectomy, and reviews the literature for comparison with three other IANI-prevention techniques. Materials and Methods. MGC was performed on two MTMs with nerve involvement and severe periodontal pockets on the distal of MSM. Modifications were: stabilizing the root stump to prevent intraoperative movement, creation of a large intrabony space for bone graft material, and grafting for periodontal healing while minimizing the possibility of post-op root migration. Results. Excellent overall periodontal improvement, with probing depths reduced to 3-4 mm. Panoramic radiograph displayed remarkable bone regeneration. No residual root migration was evident at the two year follow up. Conclusion. MGC may be a good alternative, especially in cases with periodontal defects on the distal of MSM. It may also help to minimize inadvertent intraoperative root removal and postoperative root migration.

  6. Histomorphological observations on preserved peripheral nerve allografts. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kalopissis, T.; Triandafyllou, N.; Karaizas, P.

    1978-01-01

    Six specimen of a human n. tibialis posterior were lyophylized and irradiated with ..gamma..-ray doses, varying from 1 to 4 Mrd. Subsequently, hematoxylin and eosin stained sections were examined and compared with those of an untreated specimen. The main alterations are the rearrangement of the epineural connective tissue of the interperineural spaces in a reticulum of varying regularity, depending on the ..gamma..-ray dose applied, the condensation of the endoneural connective tissue to trabeculae containing the destroyed nerve fibers and forming irregular tubular spaces and, to a varying degree and depending on the ..gamma..-ray dose applied, the dilatation of the - intratrabecular - spaces containing the fibers to tubules of varying regularity, again depending on the ..gamma..-ray dose applied. The hope for suitability of histological samples as a means of quality control of lyophylized and irradiated grafts does not yet seem justified.

  7. Developing Creativity: Artificial Barriers in Artificial Intelligence

    OpenAIRE

    Jennings, Kyle E.

    2010-01-01

    The greatest rhetorical challenge to developers of creative artificial intelligence systems is convincingly arguing that their software is more than just an extension of their own creativity. This paper suggests that “creative autonomy,” which exists when a system not only evaluates creations on its own, but also changes its standards without explicit direction, is a necessary condition for making this argument. Rather than requiring that the system be hermetically sealed to avoid perceptions...

  8. Posterior repair with perforated porcine dermal graft

    Directory of Open Access Journals (Sweden)

    G. Bernard Taylor

    2008-02-01

    Full Text Available OBJECTIVE: To compare postoperative vaginal incision separation and healing in patients undergoing posterior repair with perforated porcine dermal grafts with those that received grafts without perforations. Secondarily, the tensile properties of the perforated and non-perforated grafts were measured and compared. MATERIALS AND METHODS: This was a non-randomized retrospective cohort analysis of women with stage II or greater rectoceles who underwent posterior repair with perforated and non-perforated porcine dermal grafts (PelvicolTM CR Bard Covington, GA USA. The incidence of postoperative vaginal incision separation (dehiscence was compared. A secondary analysis to assess graft tensile strength, suture pull out strength, and flexibility after perforation was performed using standard test method TM 0133 and ASTM bending and resistance protocols. RESULTS: Seventeen percent of patients (21/127 who received grafts without perforations developed vaginal incision dehiscence compared to 7% (5/71 of patients who received perforated grafts (p = 0.078. Four patients with vaginal incision dehiscence with non-perforated grafts required surgical revision to facilitate healing. Neither tensile strength or suture pull out strength were significantly different between perforated and non-perforated grafts (p = 0.81, p = 0.29, respectively. There was no difference in the flexibility of the two grafts (p = 0.20. CONCLUSION: Perforated porcine dermal grafts retain their tensile properties and are associated with fewer vaginal incision dehiscences.

  9. Imaging the ocular motor nerves

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Teresa [Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: T.A.Ferreira@lumc.nl; Verbist, Berit [Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: B.M.Verbist@lumc.nl; Buchem, Mark van [Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: M.A.van_Buchem@lumc.nl; Osch, Thijs van [C.J. Gorter for High-Field MRI, Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: M.J.P.van_Osch@lumc.nl; Webb, Andrew [C.J. Gorter for High-Field MRI, Department of Radiology, Leiden University Medical Center (Netherlands)], E-mail: A.Webb@lumc.nl

    2010-05-15

    The ocular motor nerves (OMNs) comprise the oculomotor, trochlear and the abducens nerves. According to their course, they are divided into four or five anatomic segments: intra-axial, cisternal, cavernous and intra-orbital and, for the abducens nerve, an additional interdural segment. Magnetic resonance imaging is the imaging method of choice in the evaluation of the normal and pathologic ocular motor nerves. CT still plays a limited but important role in the evaluation of the intraosseous portions at the skull base and bony foramina. We describe for each segment of these cranial nerves, the normal anatomy, the most appropriate image sequences and planes, their imaging appearance and pathologic conditions. Magnetic resonance imaging with high magnetic fields is a developing and promising technique. We describe our initial experience with a Phillips 7.0 T MRI scanner in the evaluation of the brainstem segments of the OMNs. As imaging becomes more refined, an understanding of the detailed anatomy is increasingly necessary, as the demand on radiology to diagnose smaller lesions also increases.

  10. Evaluation of the graft flow reserve after coronary artery bypass grafting by stress {sup 201}Tl myocardial SPECT. Comparison between arterial grafts and venous grafts

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Akihiro; Taki, Junichi; Nakajima, Kenichi; Kawasuji, Michio; Tonami, Norihisa [Kanazawa Univ. (Japan). School of Medicine

    1997-01-01

    We performed stress {sup 201}Tl myocardial SPECT to evaluate ischemia and perfusion reserve after coronary artery bypass grafting (CABG). A total of 103 patients was performed stress {sup 201}Tl myocardial SPECT one month after CABG. Each patient`s myocardium was divided into 9 segments and visually evaluated using five grade scoring system (0=defect, 1=severe decrease, 2=moderate decrease, 3=mild decrease, 4=normal uptake). Eleven of 133 (8.27%) segments covered by patent venous grafts showed reversible {sup 201}Tl defect, however, 36 of 117 (30.8%) segments which covered by patent arterial grafts showed reversible {sup 201}Tl defect. This finding was observed more significantly in arterial grafts than in venous grafts (p<0.001). These finding suggests that arterial grafts have lower flow capacity than venous grafts at peak exercise. (author)

  11. Evaluation of the graft flow reserve after coronary artery bypass grafting by stress 201Tl myocardial SPECT. Comparison between arterial grafts and venous grafts

    International Nuclear Information System (INIS)

    We performed stress 201Tl myocardial SPECT to evaluate ischemia and perfusion reserve after coronary artery bypass grafting (CABG). A total of 103 patients was performed stress 201Tl myocardial SPECT one month after CABG. Each patient's myocardium was divided into 9 segments and visually evaluated using five grade scoring system (0=defect, 1=severe decrease, 2=moderate decrease, 3=mild decrease, 4=normal uptake). Eleven of 133 (8.27%) segments covered by patent venous grafts showed reversible 201Tl defect, however, 36 of 117 (30.8%) segments which covered by patent arterial grafts showed reversible 201Tl defect. This finding was observed more significantly in arterial grafts than in venous grafts (p<0.001). These finding suggests that arterial grafts have lower flow capacity than venous grafts at peak exercise. (author)

  12. Starch Modification by Graft Copolymerization of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    刘瑞贤; 李莉; 茹宗玲; 张黎明; 高建平; 田汝川

    2003-01-01

    The graft copolymerization of acrylonitrile (AN) onto starch under the initiation of potassium permanganate was investigated. The effect of various reaction conditions on the graft copolymerization was studied. The relationships between the grafting rate and the initiator concentration of potassium permanganate, monomer acrylonitrile and backbone starch, as well as reaction temperature were established. The oxidation reaction of starch with manganic ions and valence changes of manganic ions during the graft copolymerization were discussed. The results show that manganic ion Mn7+ underwent a series of valence changes during the graft copolymerization: Mn(Ⅶ) → Mn(Ⅳ) → Mn(Ⅲ) → Mn(Ⅱ). The grafting rate of the graft copolymerization of acrylonitrile onto starch is also given.

  13. Development of biomaterial scaffold for nerve tissue engineering: Biomaterial mediated neural regeneration

    Directory of Open Access Journals (Sweden)

    Sethuraman Swaminathan

    2009-11-01

    Full Text Available Abstract Neural tissue repair and regeneration strategies have received a great deal of attention because it directly affects the quality of the patient's life. There are many scientific challenges to regenerate nerve while using conventional autologous nerve grafts and from the newly developed therapeutic strategies for the reconstruction of damaged nerves. Recent advancements in nerve regeneration have involved the application of tissue engineering principles and this has evolved a new perspective to neural therapy. The success of neural tissue engineering is mainly based on the regulation of cell behavior and tissue progression through the development of a synthetic scaffold that is analogous to the natural extracellular matrix and can support three-dimensional cell cultures. As the natural extracellular matrix provides an ideal environment for topographical, electrical and chemical cues to the adhesion and proliferation of neural cells, there exists a need to develop a synthetic scaffold that would be biocompatible, immunologically inert, conducting, biodegradable, and infection-resistant biomaterial to support neurite outgrowth. This review outlines the rationale for effective neural tissue engineering through the use of suitable biomaterials and scaffolding techniques for fabrication of a construct that would allow the neurons to adhere, proliferate and eventually form nerves.

  14. Effect of intrathymic injection of allogene antigen on immune response to sciatic nerve transplantation in allogenic mice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    motor nerve conduction velocity. ② Transplanted nerve was stained with histochemical staining and observed light microscope and electron microscope. ③ Mice received mixed lymphocyte culture and delayed-typed hypersensitiveness to observe absorbency and measure depth of soles.RESULTS: All 76 mice were involved in the final analysis. ① Motor nerve conduction velocity: The nerve recovery in MHC (H-2b) antigen injection group was higher than that in allogenous nerve transplantation group, equal to immunosuppressive agent group and lower than autogenous nerve transplantation group.There were significant differences among them (P < 0.05). ② Histological changes of transplanted nerve:Light and electron microscopes demonstrated that there were a lot of regenerative nerve fibers in autogenous nerve transplantation group, immunosuppressive agent group and MHC (H-2b) antigen injection group, and all nerve fibers passed grafts. ③ Immunological examination: There was no significant difference in mixed lymphocyte culture among allogenous nerve transplantation group, autogenous nerve transplantation group and MHC (H-2b) antigen injection group (P < 0.05). Depth of soles in other groups was deeper than that in the MHC (H-2b) antigen injection group, and there was significant difference (P < 0.05); that was to say,delayed-typed hypersensitiveness was remarkable.CONCLUSION: The intrathymic injection of allogene MHC antigen may induce specific immune tolerance to allogenous sciatic nerve transplantation and promote nerve survival and functional recovery.

  15. Magnetic resonance neurography. Imaging of peripheral nerves

    International Nuclear Information System (INIS)

    Magnetic resonance neurography (MRN) is a non-invasive technique using magnetic resonance imaging (MRI) in order to diagnose peripheral nerve pathologies and their underlying etiologies. MRN is already in clinical use and is now mostly used to delineate the anatomy of nerves and to establish the continuity or discontinuity of nerves in patients with traumatic nerve injuries, as well as to monitor processes of peripheral nerve degeneration and regeneration. This article reviews established and evolving novel MRN technologies with regard to their potential to meet the requirements for non-invasive imaging of peripheral nerves in clinical settings. (orig.)

  16. Neurophysiological approach to disorders of peripheral nerve

    DEFF Research Database (Denmark)

    Crone, Clarissa; Krarup, Christian

    2013-01-01

    Disorders of the peripheral nerve system (PNS) are heterogeneous and may involve motor fibers, sensory fibers, small myelinated and unmyelinated fibers and autonomic nerve fibers, with variable anatomical distribution (single nerves, several different nerves, symmetrical affection of all nerves...... methods including nerve conduction studies and electromyography used in the study of patients suspected of having a neuropathy and the significance of the findings are discussed in detail and more novel and experimental methods are mentioned. Diagnostic considerations are based on a flow chart classifying...

  17. Study on Variant Anatomy of Sciatic Nerve

    OpenAIRE

    Adibatti, Mallikarjun; V, Sangeetha

    2014-01-01

    Introduction: Sciatic Nerve (SN) is the nerve of the posterior compartment of thigh formed in the pelvis from the ventral rami of the L4 to S3 spinal nerves. It leaves the pelvis via the greater sciatic foramen below piriformis and divides into Common Peroneal Nerve (CPN) and Tibial Nerve (TN) at the level of the upper angle of the popliteal fossa. Higher division of the sciatic nerve is the most common variation where the TN and CPN may leave the pelvis through different routes. Such variati...

  18. Principles of artificial intelligence

    CERN Document Server

    Nilsson, Nils J

    1980-01-01

    A classic introduction to artificial intelligence intended to bridge the gap between theory and practice, Principles of Artificial Intelligence describes fundamental AI ideas that underlie applications such as natural language processing, automatic programming, robotics, machine vision, automatic theorem proving, and intelligent data retrieval. Rather than focusing on the subject matter of the applications, the book is organized around general computational concepts involving the kinds of data structures used, the types of operations performed on the data structures, and the properties of th

  19. Intelligence: Real or artificial?

    OpenAIRE

    Schlinger, Henry D

    1992-01-01

    Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally r...

  20. Artificial Personality and Disfluency

    OpenAIRE

    Wester, Mirjam; Aylett, Matthew; Tomalin, Marcus; Dall, Rasmus

    2015-01-01

    The focus of this paper is artificial voices with different personalities. Previous studies have shown links between an individual's use of disfluencies in their speech and their perceived personality. Here, filled pauses (uh and um) and discourse markers (like, you know, I mean) have been included in synthetic speech as a way of creating an artificial voice with different personalities. We discuss the automatic insertion of filled pauses and discourse markers (i.e., fillers) into otherwise f...

  1. The Artificial Anal Sphincter

    OpenAIRE

    Christiansen, John

    2000-01-01

    The artificial anal sphincter as treatment for end stage anal incontinence was first described in 1987. Published series concern a total of 42 patients, with a success rate of approximately 80%. Infection has been the most serious complication, but a number of technical complications related to the device have also occurred and required revisional procedures in 40% to 60% of the patients. The artificial anal sphincter may be used for the same indications as dynamic graciloplasty except in pat...

  2. Technologies for repairing peripheral nerve injury Progress in domestic and foreign investigations

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    into the view of researchers. The main aim of technique referred above is to recover the physiological structure and function as much as possible. However,the clinical applications have a long way to go for the series of restrictions from the problems of rejection, etc.The clinical repair of peripheral nerve injury still mainly depends on microscopic neurorrhaphy and nerve grafting at present, whereas the satisfying repair techniques are waiting for more professional researches.CONCLUSION: Restricted by techniques, microsurgery repair is still the first choice for peripheral nerve injury. Microencapsulation technique and gene therapy offer a new direction for peripheral nerve repair;tissue engineering gains great success in animal experiment together have wide prospect on clinical application, many problems wait for solution though, they will be point of following researches.

  3. Hydrophilic Silicone Resins Obtained by Radiation Grafting

    International Nuclear Information System (INIS)

    N-vinylpyrrolidone was grafted radiochemically on a silicone resin by pre-irradiation in the presence of oxygen. Under these conditions, peroxide groups capable of initiating radical copolymerization are formed. The trapped radicals do not seem to make any contribution. An RTV (Room Temperature Vulcanization) type silicone resin was used, i. e. a poly(dimethylsiloxane) crosslinked by vinyl-silane bonds. The unsaturated product was transparent. The silicones containing phenyl groups as well as saturated resins were also studied. Irradiation with 60Co gamma rays was performed in the 10-kCi irradiator of the Radiation Applications Group (GAR) at Saclay. Brief pre-irradiation tests with an electron accelerator were also performed. The amount of polyvinylpyrrolidone(PVP) grafted depends on the pre-irradiation dose and dose-rate as well as on the temperature and duration of the grafting proper. These different parameters were analysed. The grafting efficiency of PVP can be as much as 60%. The grafted copolymers are more or less opaque and coloured sections show that grafting remains peripheral. The transparency can be restored by immersion in water. The swelling in water is such that the ratio of absorbed water to grafted PVP varies between 0.8 and 1.5. When the grafting efficiency is higher than 50%, it is observed that the grafted PVP redissolves after swelling. The redissolving is due to the breaking of the grafted chains. For grafting rates below 30%, the grafted PVP silicones have notably high thermal stability. Examination of some properties of the grafted PVP silicones shows the additive nature of the properties of the grafted copolymers. Reference is made to the possible applications of these products, especially in biology and medicine. (author)

  4. Artificial skin. Jinko hifu

    Energy Technology Data Exchange (ETDEWEB)

    Kifune, K. (Unitika Ltd., Osaka (Japan))

    1993-06-15

    In order to restore the human skin wounds, the transplantation is only one measure. The transplantation can take only when own skin is used, and there is no successful example by using other person's skin. When the own skin is not sufficient due to the too vast damage, the artificial skin, which can be regenerated as it is, is required. The artificial skin is said to be the most difficult organ among the artificial organs, even though its function is quite simple. Although there are the pig skin, the collagen membrane and the synthetic materials such as the polyurethane and so forth, as the materials similar to the artificial skin, they cover the wounds just until the cuticle is formed. Recently there is a cultivated skin. Firstly the normal skin with a size of the stamp is cut off, and then the cuticle cells are taken to pieces and cultivated, and consequently it is possible to increase the area by several 10 times. In addition, there is also a trial to make the artificial skin synthetically. Its upper layer is composed of the silicon, and the lower layer is the collagen membrane with a sponge structure. The silicon, membrane can be said to be an ideal artificial skin, because it detaches naturally. The chitin, which has recently appeared as the wound protection material, is also the promising material. 3 figs.

  5. Solitary schwannoma of sciatic nerve

    International Nuclear Information System (INIS)

    A solitary schwannoma of the peripheral nerve may arise sporadically in patients who have no evidence of a genetic predetermination of von Recklinghausen's disease. In the leg, schwannomas usually appear on the flexor aspect, especially near the elbow, wrist and knee, and the feet are usually spared. A solitary schwannoma of the sciatic nerve is very rare as a case of a sciatic pain, and the CT diagnosis of such a lesion has not been previously reported. In the present case, the deeply situated, small lesion was clearly delineated with high resolution CT. (J.P.N.)

  6. Nerve lesioning with direct current

    Science.gov (United States)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  7. Imaging of the optic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Minerva [Head and Neck and Maxillofacial Radiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland)], E-mail: minerva.becker@hcuge.ch; Masterson, Karen [Head and Neck and Maxillofacial Radiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Delavelle, Jacqueline [Neuroradiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Viallon, Magalie [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Vargas, Maria-Isabel [Neuroradiology, Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland); Becker, Christoph D. [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH - 1211 Geneva 14 (Switzerland)

    2010-05-15

    This article provides an overview of the imaging findings of diseases affecting the optic nerve with special emphasis on clinical-radiological correlation and on the latest technical developments in MR imaging and CT. The review deals with congenital malformations, tumors, toxic/nutritional and degenerative entities, inflammatory and infectious diseases, compressive neuropathy, vascular conditions and trauma involving the optic nerve from its ocular segment to the chiasm. The implications of imaging findings on patient management and outcome and the importance of performing high-resolution tailored examinations adapted to the clinical situation are discussed.

  8. Functional nerve recovery after bridging a 15 mm gap in rat sciatic nerve with a biodegradable nerve guide

    NARCIS (Netherlands)

    Meek, MF; Klok, F; Robinson, PH; Nicolai, JPA; Gramsbergen, A; van der Werf, J.F.A.

    2003-01-01

    Recovery of nerve function was evaluated after bridging a 15 mm sciatic nerve gap in 51 rats with a biodegradable poly(DL-lactide-epsilon-caprolactone) nerve guide. Recovery of function was investigated by analysing the footprints, by analysing video recordings of gait, by electrically eliciting the

  9. Palsies of Cranial Nerves That Control Eye Movement

    Science.gov (United States)

    ... Medical News Palsies of Cranial Nerves That Control Eye Movement By Michael Rubin, MDCM NOTE: This is the ... Gaze Palsies Palsies of Cranial Nerves That Control Eye Movement Third Cranial Nerve (Oculomotor Nerve) Palsy Fourth Cranial ...

  10. Inflammatory peripheral facial nerve palsy. An overview

    International Nuclear Information System (INIS)

    In inflammatory peripheral facial nerve palsy pathologically intense, linear and smooth enhancement of the distal intrameatal nerve segment can always be observed on T1-w- SE- MR sequences. The other nerve segments often present with a pathological enhancement as well. On T2-w- SE sequences, a thickening of the distal intrameatal nerve segment can be observed. The pathological enhancement persists over weeks and months; even in patients with complete clinical recovery, a persistent enhancement of the distal intrameatal nerve segment can be demonstrated. No correlation can be established between the intensity of the enhancement, the clinical condition and the electrophysiological data on electroneurography. The persistent enhancement of the different nerve segments is due to a longlasting breakdown of the blood-peripheral nerve-barrier related to the process of degeneration and regeneration of the facial nerve in inflammatory palsy. (orig.)

  11. Nerve supply to the pelvis (image)

    Science.gov (United States)

    The nerves that branch off the central nervous system (CNS) provide messages to the muscles and organs for normal ... be compromised. In multiple sclerosis, the demyelinization of nerve cells may lead to bowel incontinence, bladder problems ...

  12. Prediabetes May Damage Nerves More Than Thought

    Science.gov (United States)

    ... medlineplus/news/fullstory_158274.html Prediabetes May Damage Nerves More Than Thought Early pain and tingling in ... 12, 2016 (HealthDay News) -- Prediabetes may cause more nerve damage than previously believed, researchers say. "The results ...

  13. Diabetic Neuropathies: The Nerve Damage of Diabetes

    Science.gov (United States)

    ... Organizations (PDF, 293 KB). Alternate Language URL Español Diabetic Neuropathies: The Nerve Damage of Diabetes Page Content ... treated? Points to Remember Clinical Trials What are diabetic neuropathies? Diabetic neuropathies are a family of nerve ...

  14. Optic nerve invasion of uveal melanoma

    DEFF Research Database (Denmark)

    Lindegaard, Jens; Isager, Peter; Prause, Jan Ulrik; Heegaard, Steffen

    2007-01-01

    The aim of the study was to identify the histopathological characteristics associated with the invasion of the optic nerve of uveal melanoma and to evaluate the association between invasion of the optic nerve and survival. In order to achieve this, all uveal melanomas with optic nerve invasion in...... Denmark between 1942 and 2001 were reviewed (n=157). Histopathological characteristics and depth of optic nerve invasion were recorded. The material was compared with a control material from the same period consisting of 85 cases randomly drawn from all choroidal/ciliary body melanomas without optic nerve...... 4) in one case a tumor spread along the inner limiting membrane to the optic nerve through the lamina cribrosa. Invasion of the optic nerve had no impact on all-cause mortality or melanoma-related mortality in multivariate analyses. The majority of melanomas invading the optic nerve are large...

  15. Fabrication of bioactive conduits containing the fibroblast growth factor 1 and neural stem cells for peripheral nerve regeneration across a 15 mm critical gap

    International Nuclear Information System (INIS)

    Nerve conduits are often used in combination with bioactive molecules and stem cells to enhance peripheral nerve regeneration. In this study, the acidic fibroblast growth factor 1 (FGF1) was immobilized onto the microporous/micropatterned poly (D, L-lactic acid) (PLA) nerve conduits after open air plasma treatment. PLA substrates grafted with chitosan in the presence of a small amount of gold nanoparticles (nano Au) showed a protective effect on the activity of the immobilized FGF1 in vitro. Different conduits were tested for their ability to bridge a 15 mm critical gap defect in a rat sciatic nerve injury model. Axon regeneration and functional recovery were evaluated by histology, walking track analysis and electrophysiology. Among different conduits, PLA conduits grafted with chitosan–nano Au and the FGF1 after plasma activation had the greatest regeneration capacity and functional recovery in the experimental animals. When the above conduit was seeded with aligned neural stem cells, the efficacy was further enhanced and it approached that of the autograft group. This work suggested that microporous/micropatterned nerve conduits containing bioactive growth factors may be successfully fabricated by micropatterning techniques, open plasma activation, and immobilization, which, combined with aligned stem cells, may synergistically contribute to the regeneration of the severely damaged peripheral nerve. (paper)

  16. Fabrication of bioactive conduits containing the fibroblast growth factor 1 and neural stem cells for peripheral nerve regeneration across a 15 mm critical gap.

    Science.gov (United States)

    Ni, Hsiao-Chiang; Tseng, Ting-Chen; Chen, Jeng-Rung; Hsu, Shan-Hui; Chiu, Ing-Ming

    2013-09-01

    Nerve conduits are often used in combination with bioactive molecules and stem cells to enhance peripheral nerve regeneration. In this study, the acidic fibroblast growth factor 1 (FGF1) was immobilized onto the microporous/micropatterned poly (D, L-lactic acid) (PLA) nerve conduits after open air plasma treatment. PLA substrates grafted with chitosan in the presence of a small amount of gold nanoparticles (nano Au) showed a protective effect on the activity of the immobilized FGF1 in vitro. Different conduits were tested for their ability to bridge a 15 mm critical gap defect in a rat sciatic nerve injury model. Axon regeneration and functional recovery were evaluated by histology, walking track analysis and electrophysiology. Among different conduits, PLA conduits grafted with chitosan-nano Au and the FGF1 after plasma activation had the greatest regeneration capacity and functional recovery in the experimental animals. When the above conduit was seeded with aligned neural stem cells, the efficacy was further enhanced and it approached that of the autograft group. This work suggested that microporous/micropatterned nerve conduits containing bioactive growth factors may be successfully fabricated by micropatterning techniques, open plasma activation, and immobilization, which, combined with aligned stem cells, may synergistically contribute to the regeneration of the severely damaged peripheral nerve. PMID:23880639

  17. Radiation sterilization of tissue grafts

    International Nuclear Information System (INIS)

    The Tissue Bank at the Tata Memorial Hospital was started in 1989 in collaboration with the Department of Atomic Energy, Government of India, as part of an IAEA project to promote the use of nuclear technology for peaceful purposes. The Bank produces freeze dried, gamma irradiated allografts such as skin, amniotic membrane, dura mater, fascia lata, bone blocks/chips/dust, iliac crest, femoral heads and ribs. Tissues are harvested from cadavers or obtained secondary to surgical procedures. After processing, the grafts are exposed to 25 kGy of gamma radiation. The grafts have found use in a variety of clinical conditions like burns, non-union fractures, periodontal osseous defects and surgical reconstructions. (author)

  18. Cranial Nerves IX, X, XI, and XII

    OpenAIRE

    Gillig, Paulette Marie; Sanders, Richard D.

    2010-01-01

    This article concludes the series on cranial nerves, with review of the final four (IX–XII). To summarize briefly, the most important and common syndrome caused by a disorder of the glossopharyngeal nerve (craniel nerve IX) is glossopharyngeal neuralgia. Also, swallowing function occasionally is compromised in a rare but disabling form of tardive dyskinesia called tardive dystonia, because the upper motor portion of the glossopharyngel nerve projects to the basal ganglia and can be affected b...

  19. Diverse mechanisms for assembly of branchiomeric nerves

    OpenAIRE

    Cox, Jane A.; LaMora, Angela; Stephen L Johnson; Voigt, Mark M.

    2011-01-01

    The formation of branchiomeric nerves (cranial nerves V, VII, IX and X) from their sensory, motor and glial components is poorly understood. The current model for cranial nerve formation is based on the Vth nerve, in which sensory afferents are formed first and must enter the hindbrain in order for the motor efferents to exit. Using transgenic zebrafish lines to discriminate between motor neurons, sensory neurons and peripheral glia, we show that this model does not apply to the remaining thr...

  20. Imaging the cranial nerves in cancer

    OpenAIRE

    Chong, Vincent

    2004-01-01

    The cranial nerves are often involved in head and neck malignancies. Some malignancies have a strong propensity to show perineural spread. Cranial nerve palsy may be the presenting sign of metastatic disease to the skull base. Like metastatic disease to the lungs or liver, the cranial nerves themselves may be the site of metastatic disease. In addition, cranial nerves can be injured by radiation therapy or sacrificed during surgical treatment. This paper focuses on the imaging features of per...

  1. Effect of experimental devascularization on peripheral nerves

    Directory of Open Access Journals (Sweden)

    Eros Abrantes Erhart

    1966-03-01

    Full Text Available In order to explore the functional importance of the vasa-nervorum and the nerve natural connective bed, fine nerve devascularizations were performed in ten adult dogs, using a dissecting microscope. 4 to 5 cm of the nerve vascularization and corresponding connective bed were injured. By this procedure it could be demonstrated, 30 days later, motor deficiencies and in the histological serial preparations a distad nerve degeneration, total in some fascicles and partial in others.

  2. Proximal Sciatic Nerve Intraneural Ganglion Cyst

    OpenAIRE

    Fee, Dominic B.; Swartz, Karin R.; Michael Boland; Dianne Wilson

    2009-01-01

    Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009.

  3. Shoulder posture and median nerve sliding

    Directory of Open Access Journals (Sweden)

    Dilley Andrew

    2004-07-01

    Full Text Available Abstract Background Patients with upper limb pain often have a slumped sitting position and poor shoulder posture. Pain could be due to poor posture causing mechanical changes (stretch; local pressure that in turn affect the function of major limb nerves (e.g. median nerve. This study examines (1 whether the individual components of slumped sitting (forward head position, trunk flexion and shoulder protraction cause median nerve stretch and (2 whether shoulder protraction restricts normal nerve movements. Methods Longitudinal nerve movement was measured using frame-by-frame cross-correlation analysis from high frequency ultrasound images during individual components of slumped sitting. The effects of protraction on nerve movement through the shoulder region were investigated by examining nerve movement in the arm in response to contralateral neck side flexion. Results Neither moving the head forward or trunk flexion caused significant movement of the median nerve. In contrast, 4.3 mm of movement, adding 0.7% strain, occurred in the forearm during shoulder protraction. A delay in movement at the start of protraction and straightening of the nerve trunk provided evidence of unloading with the shoulder flexed and elbow extended and the scapulothoracic joint in neutral. There was a 60% reduction in nerve movement in the arm during contralateral neck side flexion when the shoulder was protracted compared to scapulothoracic neutral. Conclusion Slumped sitting is unlikely to increase nerve strain sufficient to cause changes to nerve function. However, shoulder protraction may place the median nerve at risk of injury, since nerve movement is reduced through the shoulder region when the shoulder is protracted and other joints are moved. Both altered nerve dynamics in response to moving other joints and local changes to blood supply may adversely affect nerve function and increase the risk of developing upper quadrant pain.

  4. Isolated trochlear nerve palsy with midbrain hemorrhage

    Directory of Open Access Journals (Sweden)

    Raghavendra S

    2010-01-01

    Full Text Available Midbrain hemorrhage causing isolated fourth nerve palsy is extremely rare. Idiopathic, traumatic and congenital abnormalities are the most common causes of fourth nerve palsy. We report acute isolated fourth nerve palsy in an 18-year-old lady due to a midbrain hemorrhage probably due to a midbrain cavernoma. The case highlights the need for neuroimaging in selected cases of isolated trochlear nerve palsy.

  5. Posterior Interosseous Nerve Syndrome from Thermal Injury

    OpenAIRE

    Singh, Vijay A.; Rami E. Michael; Duy-Bao P. Dinh; Scott Bloom; Michael Cooper

    2014-01-01

    Background. Due to anatomical proximity to bone, the radial nerve is the most frequently injured major nerve of the upper extremity, frequently secondary to fractures (Li et al. (2013)). We describe an incidence when a branch of the radial nerve is injured as a result of a thermal injury. Observation. Radial nerve injury can occur anywhere along the anatomical course with varied etiologies, but commonly related to trauma. The most frequent site is in the proximal forearm involving the posteri...

  6. Secondary digital nerve repair in the foot with resorbable p(DLLA-epsilon-CL) nerve conduits

    NARCIS (Netherlands)

    Meek, MF; Nicolai, JPA; Robinson, PH

    2006-01-01

    Nerve guides are increasingly being used in peripheral nerve repair. In the last decade, Much preclinical research has been undertaken into a resorbable nerve guide composed of p(DLLA-epsilon-CL). This report describes the results of secondary digital nerve reconstruction in the foot in a patient wi

  7. Spinal accessory nerve schwannomas masquerading as a fourth ventricular lesion

    OpenAIRE

    Shyam Sundar Krishnan; Sivaram Bojja; Madabhushi Chakravarthy Vasudevan

    2015-01-01

    Schwannomas are benign lesions that arise from the nerve sheath of cranial nerves. The most common schwannomas arise from the 8 th cranial nerve (the vestibulo-cochlear nerve) followed by trigeminal and facial nerves and then from glossopharyngeal, vagus, and spinal accessory nerves. Schwannomas involving the oculomotor, trochlear, abducens and hypoglossal nerves are very rare. We report a very unusual spinal accessory nerve schwannoma which occupied the fourth ventricle and extended inferior...

  8. Ganglioglioma of the trigeminal nerve: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Athale, S.; Jinkins, J.R. [Neuroradiology Section, The University of Texas Health Science Center at San Antonio, 7703 F. Curl Drive, San Antonio, TX 78284-7800 (United States); Hallet, K.K. [Neuropathology Department, The University of Texas Health Science Center at San Antonio, Texas (United States)

    1999-08-01

    Ganglioglioma of the cranial nerves is extremely rare; only a few cases involving the optic nerves have been reported. We present a case of ganglioglioma of the trigeminal nerve, which was isointense with the brain stem on all MRI sequences and showed no contrast enhancement. (orig.) With 2 figs., 6 refs.

  9. Ephaptic coupling of myelinated nerve fibers

    DEFF Research Database (Denmark)

    Binczak, S.; Eilbeck, J. C.; Scott, Alwyn C.

    Numerical predictions of a simple myelinated nerve fiber model are compared with theoretical results in the continuum and discrete limits, clarifying the nature of the conduction process on an isolated nerve axon. Since myelinated nerve fibers are often arranged in bundles, this model is used to...

  10. Bilateral high division of sciatic nerve

    Directory of Open Access Journals (Sweden)

    K. Shwetha

    2014-08-01

    Full Text Available Sciatic nerve is the thickest nerve in the body formed by the sacral plexus from L4 to S3 in the lesser pelvis. It emerges through the greater sciatic foramen below the piriformis and enter the gluteal region. Then the nerve passes on the back of the thigh and at the level of superior angle of popliteal fossa it terminates by dividing into tibial and common peroneal nerve. The knowledge of anatomical variations in the division of nerve is important for various surgical and anaesthetic procedures. During routine dissection in the department of anatomy, Mysore Medical College and Research Institute, Mysore, a rare bilateral high division of sciatic nerve was observed in a female cadaver aged about 40 years. In the present case there was bilateral high division of sciatic nerve. The nerve was seen dividing into two branches before it emerges through the greater sciatic foramen. The tibial nerve was entering the gluteal region below the piriformis muscle and common peroneal nerve was entering by piercing the piriformis. The knowledge of this variation is important as the nerve may get compressed with surrounding anatomical structures resulting in non discogenic sciatica. The awareness of variations is important for surgeons during various procedures like fracture, posterior dislocation of hip joint and hip joint replacement. The anatomical variations are important during deep intramuscular injections in gluteal region and also for anaesthetists during sciatic nerve block. [Int J Res Med Sci 2014; 2(4.000: 1785-1787

  11. Disorders of Cranial Nerves IX and X

    OpenAIRE

    Erman, Audrey B.; Kejner, Alexandra E.; Hogikyan, Norman D.; Eva L Feldman

    2009-01-01

    The glossopharyngeal and vagus nerves mediate the complex interplay between the many functions of the upper aerodigestive tract. Defects may occur anywhere from the brainstem to the peripheral nerve and can result in significant impairment in speech, swallowing, and breathing. Multiple etiologies can produce symptoms. This review will broadly examine the normal functions, clinical examination, and various pathologies of cranial nerves IX and X.

  12. Bilateral median nerve palsy in a cyclist.

    OpenAIRE

    Braithwaite, I J

    1992-01-01

    Cyclists are prone to a number of sport-related musculoskeletal injuries, mainly of the lower limb. Nerve compression injuries are relatively rare, though in the hand ulnar nerve compression is well described. We describe a case of bilateral median nerve compression caused by cycling.

  13. 21 CFR 882.5275 - Nerve cuff.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nerve cuff. 882.5275 Section 882.5275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5275 Nerve cuff. (a) Identification. A nerve...

  14. Types of neural guides and using nanotechnology for peripheral nerve reconstruction

    Directory of Open Access Journals (Sweden)

    Esmaeil Biazar

    2010-10-01

    Full Text Available Esmaeil Biazar1, MT Khorasani2, Naser Montazeri1, Khalil Pourshamsian1, Morteza Daliri3, Mostafa Rezaei T4, Mahmoud Jabarvand B5, Ahad Khoshzaban5, Saeed Heidari K4,5, Mostafa Jafarpour6, Ziba Roviemiab71Department of Chemistry, Islamic Azad University-Tonekabon Branch, Iran; 2Biomaterial Department of Iran Polymer and Petrochemical Institute, Tehran, Iran; 3National Research Center for Genetic Engineering and Biotechnology, Tehran, Iran; 4Proteomics Research Center, Faculty of Paramedical Sciences, Shaheed Beheshti University of Medical Sciences, Tehran, Iran; 5Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran; 6Department of Microbiology, Islamic Azad University-Tonekabon Branch, Iran; 7Biomedical Engineering Faculty, Islamic Azad University-Science and Research Branch, Tehran, IranAbstract: Peripheral nerve injuries can lead to lifetime loss of function and permanent disfigurement. Different methods, such as conventional allograft procedures and use of biologic tubes present problems when used for damaged peripheral nerve reconstruction. Designed scaffolds comprised of natural and synthetic materials are now widely used in the reconstruction of damaged tissues. Utilization of absorbable and nonabsorbable synthetic and natural polymers with unique characteristics can be an appropriate solution to repair damaged nerve tissues. Polymeric nanofibrous scaffolds with properties similar to neural structures can be more effective in the reconstruction process. Better cell adhesion and migration, more guiding of axons, and structural features, such as porosity, provide a clearer role for nanofibers in the restoration of neural tissues. In this paper, basic concepts of peripheral nerve injury, types of artificial and natural guides, and methods to improve the performance of tubes, such as orientation, nanotechnology applications for nerve reconstruction, fibers and nanofibers, electrospinning methods, and

  15. Overview of the Cranial Nerves

    Science.gov (United States)

    ... speech Because both the 9th and 10th cranial nerves control swallowing and the gag reflex, they are tested together. The person is asked ... of palate movement). 10th Vagus Swallowing, the gag reflex, and speech ... 11th Accessory Neck turning and shoulder shrugging ...

  16. Cranial nerve palsies in childhood.

    Science.gov (United States)

    Lyons, C J; Godoy, F; ALQahtani, E

    2015-02-01

    We review ocular motor cranial nerve palsies in childhood and highlight many of the features that differentiate these from their occurrence in adulthood. The clinical characteristics of cranial nerve palsies in childhood are affected by the child's impressive ability to repair and regenerate after injury. Thus, aberrant regeneration is very common after congenital III palsy; Duane syndrome, the result of early repair after congenital VI palsy, is invariably associated with retraction of the globe in adduction related to the innervation of the lateral rectus by the III nerve causing co-contraction in adduction. Clinical features that may be of concern in adulthood may not be relevant in childhood; whereas the presence of mydriasis in III palsy suggests a compressive aetiology in adults, this is not the case in children. However, the frequency of associated CNS abnormalities in III palsy and the risk of tumour in VI palsy can be indications for early neuroimaging depending on presenting features elicited through a careful history and clinical examination. The latter should include the neighbouring cranial nerves. We discuss the impact of our evolving knowledge of congenital cranial dysinnervation syndromes on this field. PMID:25572578

  17. Intraoral myxoid nerve sheath tumour

    NARCIS (Netherlands)

    Schortinghuis, J; Hille, JJ; Singh, S

    2001-01-01

    A case of an intraoral myxoid nerve sheath tumour of the dorsum of the tongue in a 73-year-old Caucasian male is reported. This case describes the oldest patient with this pathology to date. Immunoperoxidase staining for neuronspecific enolase (NSE) and epithelial membrane antigen (EMA) expression d

  18. Nerve injury associated with orthognathic surgery. Part 1: UK practice and motor nerve injuries.

    Science.gov (United States)

    Bowe, D C; Gruber, E A; McLeod, N M H

    2016-05-01

    The head and neck is anatomically complex, and several nerves are at risk during orthognathic operations. Some injuries to nerves are reported more commonly than others. To find out what consultant surgeons tell their patients about the prevalence of common nerve injuries before orthognathic operations, we did a postal survey of fellows of the British Association of Oral and Maxillofacial Surgeons (BAOMS). We also reviewed published papers to find out the reported incidence of injuries to cranial motor nerves during orthognathic operations. Only injuries to the facial nerve were commonly reported, and we found only case reports about injuries to the oculomotor, abducens, and trochlear nerves. The risk of temporary facial nerve palsy reported was 0.30/100 nerves (95% CI 0.23 to 0.50) and permanent facial nerve palsy was 0.06/100 nerves (95% CI 0.02 to 0.15). PMID:26935213

  19. The Diagnostic Value of Nerve Ultrasound in an Atypical Palmar Cutaneous Nerve Lesion.

    Science.gov (United States)

    Zanette, Giampietro; Tamburin, Stefano

    2016-07-01

    Detailed knowledge of the fascicular anatomy of peripheral nerves is important for microsurgical repair and functional electrostimulation.We report a patient with a lesion on the left palmar cutaneous branch of the median nerve (PCBMN) and sensory signs expanding outside the PCBMN cutaneous innervation territory. Nerve conduction study showed the absence of left PCBMN sensory nerve action potential, but apparently, no median nerve (MN) involvement. Nerve ultrasound documented a neuroma of the left PCBMN and a coexistent lateral neuroma of the left MN in the carpal tunnel after the PCBMN left the main nerve trunk.Nerve ultrasound may offer important information in patients with peripheral nerve lesions and atypical clinical and/or nerve conduction study findings. The present case may shed some light on the somatotopy of MN fascicles at the wrist. PMID:26945219

  20. Periumbilical fat auto-graft associated to a porous orbital implant for socket reconstruction after enucleation.

    Science.gov (United States)

    Medel, Ramon; Alonso, Tirso; Pelaez, Francisco; Vasquez, LuzMaria

    2016-08-01

    Having to remove the sclera, fat and the optic nerve in patients undergoing an enucleation, translates in a larger volume that needs to be replaced to achieve good motility and aesthetic results. Using a 20 or 22 mm implant can only partially replace the removed volume. We report the results of our enucleation technique, which includes the use of a porous orbital implant combined with a primary fat graft to replace a higher percentage of the removed volume to achieve a better cosmetic outcome and to avoid implant related complications in high risk patients. Prospective, non-randomized study of enucleated patients for whom porous orbital implantation was performed with anterior placement of a fat auto-graft. The development of implant extrusion or exposure was recorded as well as the presence of conjunctival wound dehiscence and infection. Orbital volume was clinically and radiologically evaluated as well. Twenty-eight patients were included, with a postop follow-up of at least 6 months (6-79 months). No cases of migration or extrusion were found. One case of a large exposure resolved completely. All MRI demonstrated proper implant-graft integration and vascularisation. The aesthetic result and the symmetry were very adequate, with Hertel differences of less than 2 mm in all cases and good motility range. The fat graft is well tolerated, showing low incidence of implant-related complications whilst maintaining good volume and motility. PMID:27322024

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Grafting rays fellow travel Teichmuller geodesics

    CERN Document Server

    Choi, Young-Eun; Rafi, Kasra

    2010-01-01

    Given a measured geodesic lamination on a hyperbolic surface, grafting the surface along multiples of the lamination defines a path in Teichmuller space, called the grafting ray. We show that every grafting ray, after reparametrization, is a Teichmuller quasi-geodesic and stays in a bounded neighborhood of a Teichmuller geodesic. As part of our approach, we show that grafting rays have controlled dependence on the starting point. That is, for any measured geodesic lamination Lambda, the map of Teichmuller space which is defined by grafting along Lambda is L-Lipschitz with respect to the Teichmuller metric, where L is a universal constant. This Lipschitz property follows from an extension of grafting to an open neighborhood of Teichmuller space in the space of quasi-Fuchsian groups.

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

    LENUS (Irish Health Repository)

    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.

  4. 咬肌神经-面神经吻合:跨面神经移植手术的有效补充%Masseter-Facial Nerve Coaptation: An Supplemental Technique for Facial Nerve Reconstruction

    Institute of Scientific and Technical Information of China (English)

    王炜; 杨川

    2011-01-01

    Objective To identify the feasibility of the procedure of Masseter-Facial Nerve coaptation. Methods Two patients suffered from acoustic neuroma resection were performed cross-facial nerve grafting combined with partial Masseter-Facial Nerve coaptation. Results Both of them had an natural smile and eye closure when biting. No mastication disorder and depression on face were found. Conclusion It is an effective procedure to re-innervate the paralytic muscle quickly and is an augmentation for Cross-facial nerve grafting.%目的 初步阐述咬肌神经-面神经吻合手术的方法和疗效.方法 2例听神经瘤术后完全性面瘫患者,进行跨面神经移植术和患侧部分咬肌神经-面神经吻合手术.结果 术后3个月,患者咬牙后可将口角上提和闭合眼睛,咀嚼功能没有影响,面部未出现凹陷畸形.结论 咬肌神经-面神经吻合可以有效、快速地重建面部肌肉的神经支配,是跨面神经移植手术的有效补充.

  5. The unique axon trajectory of the accessory nerve is determined by intrinsic properties of the neural tube in the avian embryo.

    Science.gov (United States)

    Bai, Zhongtian; Pu, Qin; Haque, Ziaul; Wang, Jianlin; Huang, Ruijin

    2016-05-01

    The accessory nerve is a cranial nerve, composed of only motor axons, which control neck muscles. Its axons ascend many segments along the lateral surface of the cervical spinal cord and hindbrain. At the level of the first somite, they pass ventrally through the somitic mesoderm into the periphery. The factors governing the unique root trajectory are unknown. Ablation experiments at the accessory nerve outlet points have shown that somites do not regulate the trajectory of the accessory nerve fibres. Factors from the neural tube that may control the longitudinal pathfinding of the accessory nerve fibres were tested by heterotopic transplantations of an occipital neural tube to the cervical and thoracic level. These transplantations resulted in a typical accessory nerve trajectory in the cervical and thoracic spinal cord. In contrast, cervical neural tube grafts were unable to give rise to the typical accessory nerve root pattern when transplanted to occipital level. Our results show that the formation of the unique axon root pattern of the accessory nerve is an intrinsic property of the neural tube. PMID:26955910

  6. The Use of Fiber-Reinforced Scaffolds Cocultured with Schwann Cells and Vascular Endothelial Cells to Repair Rabbit Sciatic Nerve Defect with Vascularization

    Directory of Open Access Journals (Sweden)

    Hongyang Gao

    2013-01-01

    Full Text Available To explore the feasibility of biodegradable fiber-reinforced 3D scaffolds with satisfactory mechanical properties for the repair of long-distance sciatic nerve defect in rabbits and effects of vascularized graft in early stage on the recovery of neurological function, Schwann cells and vascular endothelial cells were cocultured in the fiber-reinforced 3D scaffolds. Experiment group which used prevascularized nerve complex for the repair of sciatic nerve defect and control group which only cultured with Schwann cells were set. The animals in both groups underwent electromyography to show the status of the neurological function recovery at 4, 8, and 16 weeks after the surgery. Sciatic nerve regeneration and myelination were observed under the light microscope and electron microscope. Myelin sheath thickness, axonal diameter, and number of myelinated nerve fiber were quantitatively analyzed using image analysis system. The recovery of foot ulcer, the velocity of nerve conduction, the number of regenerating nerve fiber, and the recovery of ultrastructure were increased in the experimental group than those in the control group. Prevascularized tissue engineered fiber-reinforced 3D scaffolds for the repair of sciatic nerve defects in rabbits can effectively promote the recovery of neurological function.

  7. The use of fiber-reinforced scaffolds cocultured with Schwann cells and vascular endothelial cells to repair rabbit sciatic nerve defect with vascularization.

    Science.gov (United States)

    Gao, Hongyang; You, Yang; Zhang, Guoping; Zhao, Feng; Sha, Ziyi; Shen, Yong

    2013-01-01

    To explore the feasibility of biodegradable fiber-reinforced 3D scaffolds with satisfactory mechanical properties for the repair of long-distance sciatic nerve defect in rabbits and effects of vascularized graft in early stage on the recovery of neurological function, Schwann cells and vascular endothelial cells were cocultured in the fiber-reinforced 3D scaffolds. Experiment group which used prevascularized nerve complex for the repair of sciatic nerve defect and control group which only cultured with Schwann cells were set. The animals in both groups underwent electromyography to show the status of the neurological function recovery at 4, 8, and 16 weeks after the surgery. Sciatic nerve regeneration and myelination were observed under the light microscope and electron microscope. Myelin sheath thickness, axonal diameter, and number of myelinated nerve fiber were quantitatively analyzed using image analysis system. The recovery of foot ulcer, the velocity of nerve conduction, the number of regenerating nerve fiber, and the recovery of ultrastructure were increased in the experimental group than those in the control group. Prevascularized tissue engineered fiber-reinforced 3D scaffolds for the repair of sciatic nerve defects in rabbits can effectively promote the recovery of neurological function. PMID:24490158

  8. Artificial intelligence in nanotechnology

    International Nuclear Information System (INIS)

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines. (topical review)

  9. Novel expansion techniques for skin grafts

    Science.gov (United States)

    Kadam, Dinesh

    2016-01-01

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

  10. Use of a porcine dermal collagen graft (Permacol) in parotid surgery.

    Science.gov (United States)

    Papadogeorgakis, Nikolaos; Petsinis, Vasilis; Christopoulos, Panagiotis; Mavrovouniotis, Nikolaos; Alexandridis, Constantinos

    2009-07-01

    Our aim was to present the results of the use of porcine dermal collagen graft (Permacol) in the prevention of Frey's syndrome and face-contouring aesthetic deformities after operations on the parotid. We treated 19 patients with parotid tumours. After resection, a Permacol sheet was applied to the perimeter of the tissue deficit so that it was fully covered, and was sutured firmly. This technique produced satisfactory aesthetic results with good facial contouring in all patients. It also protected the exposed parotid nerve plexus, and none of the patients developed Frey's syndrome. Permacol produced good results in both postoperative facial contouring and prevention of Frey's syndrome. PMID:18963286

  11. Peripheral nerve blocks in patients with Ehlers-Danlos syndrome, hypermobility type: a report of 2 cases.

    Science.gov (United States)

    Patzkowski, Michael S

    2016-03-01

    Ehlers-Danlos syndrome is an inherited disorder of collagen production that results in multiorgan dysfunction. Patients with hypermobility type display skin hyperextensibility and joint laxity, which can result in chronic joint instability, dislocation, peripheral neuropathy, and severe musculoskeletal pain. A bleeding diathesis can be found in all subtypes of varying severity despite a normal coagulation profile. There have also been reports of resistance to local anesthetics in these patients. Several sources advise against the use of regional anesthesia in these patients citing the 2 previous features. There have been reports of successful neuraxial anesthesia, but few concerning peripheral nerve blocks, none of which describe nerves of the lower extremity. This report describes 2 cases of successful peripheral regional anesthesia in the lower extremity. In case 1, a 16-year-old adolescent girl with hypermobility type presented for osteochondral grafting of tibiotalar joint lesions. She underwent a popliteal sciatic (with continuous catheter) and femoral nerve block under ultrasound guidance. She proceeded to surgery and tolerated the procedure under regional block and intravenous sedation. She did not require any analgesics for the following 15 hours. In case 2, an 18-year-old woman with hypermobility type presented for medial patellofemoral ligament reconstruction for chronic patella instability. She underwent a saphenous nerve block above the knee with analgesia in the distribution of the saphenous nerve lasting for approximately 18 hours. There were no complications in either case. Prohibitions against peripheral nerve blocks in patients with Ehlers-Danlos syndrome, hypermobility type, appear unwarranted. PMID:26897449

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Novel block, graft and random copolymers for biomedical applications

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Jankova Atanasova, Katja; Tanaka, Masaru;

    Despite the simple structure, poly(2-methoxyethyl acrylate) (PMEA) shows excellent blood compatibility [1]. Both the freezing-bound water (intermediate water: preventing the biocomponents from directly contacting the polymer surface) and non-freezing water on the polymer surface play important ro...... copolymers with MMA [4] utilizing ATRP. Here we present other block, graft and random copolymers of MEA intended for biomedical applications. These macromolecular architectures have been constructed by employing controlled radical polymerization methods such as RAFT and ATRP....... roles for this [2]. An artificial lung (oxygenator), already in use, is coated with high MW PMEA prepared by radical polymerization with AIBN [2]. To broaden the possibilities for designing biomedical devices [3] and inspired from these findings we first prepared homo polymers of MEA and their block...

  15. High-strength mineralized collagen artificial bone

    Science.gov (United States)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  16. Hydrophilic PCU scaffolds prepared by grafting PEGMA and immobilizing gelatin to enhance cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Changcan; Yuan, Wenjie; Khan, Musammir; Li, Qian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin) Tianjin 300072 (China); Yao, Fanglian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Zhang, Wencheng, E-mail: wenchengzhang@yahoo.com [Department of Physiology and Pathophysiology, Logistics University of Chinese People' s Armed Police Force, Tianjin 300162 (China)

    2015-05-01

    Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds. - Graphical abstract: PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatin onto the surface of aminated PCU scaffolds (method a). To increase the immobilization amount of gelatin, PEGMAs were grafted onto the scaffold surface by SI-ATRP. PCU-g-PEGMA-g-gelatin scaffolds were prepared by method b. The gelatin modified scaffolds exhibited high hydrophilicity, low platelet adhesion, perfect anti-hemolytic activity, and excellent cell adhesion and proliferation capacity. They might have potential applications as tissue engineering scaffolds for artificial blood vessels. - Highlights: • Hydrophilic scaffolds were prepared by grafting PEGMA and immobilization of gelatins. • Grafting PEGMA enhanced the immobilization amount of gelatin

  17. Hydrophilic PCU scaffolds prepared by grafting PEGMA and immobilizing gelatin to enhance cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds. - Graphical abstract: PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatin onto the surface of aminated PCU scaffolds (method a). To increase the immobilization amount of gelatin, PEGMAs were grafted onto the scaffold surface by SI-ATRP. PCU-g-PEGMA-g-gelatin scaffolds were prepared by method b. The gelatin modified scaffolds exhibited high hydrophilicity, low platelet adhesion, perfect anti-hemolytic activity, and excellent cell adhesion and proliferation capacity. They might have potential applications as tissue engineering scaffolds for artificial blood vessels. - Highlights: • Hydrophilic scaffolds were prepared by grafting PEGMA and immobilization of gelatins. • Grafting PEGMA enhanced the immobilization amount of gelatin

  18. EXPERIMENTAL SCIATIC NERVE REPAIRED BY ACELLULAR NERVE XENOGRAFTS LMPLANTED WITH BMSCS IN RATS%脱细胞异种神经移植体复合BMSCs修复大鼠坐骨神经缺损的研究

    Institute of Scientific and Technical Information of China (English)

    贾桦; 王莹; 张莲香; 马全瑞; 佟雷; 佟晓杰

    2014-01-01

    目的:对脱细胞异种神经的生物相容性进行评价,证明应用其复合BMSCs促进神经再生和功能恢复的效果。方法:采用化学萃取法制备兔的脱细胞神经,应用扫描电镜观察其超微结构;将BMSCs种植到神经支架构建神经移植体,体外培养后观察细胞形态;用构建的异种神经移植体桥接大鼠坐骨神经缺损,术后8周,检测胫前肌湿重比率,对再生神经进行组织形态学分析;并应用免疫荧光染色检测神经内NGF的表达。结果:脱细胞异种神经较完整地保留了天然立体的施万细胞基底膜管结构,完全地移除了神经内的施万细胞、轴突和髓鞘成分;在体外培养中支持种植的BMSCs黏附和生长。神经移植术后,与单纯异种脱细胞神经移植组相比,复合BMSCs的异种神经移植体移植能使胫前肌湿重比率增加、有髓神经纤维数目、髓鞘厚度和轴突直径增加;增加再生神经内NGF的表达。结论:异种脱细胞神经移植体具备天然的立体结构,移除了施万细胞、髓鞘等抗原成分;神经支架无细胞毒性,具有良好的细胞相容性;复合BMSCs的异种神经移植体可显著地促进神经再生及功能恢复。%Objective:To evaluate the biocompatibility of acellular nerve xenografts , after bridging nerve gaps by utilizing the BM-SCs-combined xenogenic nerve grafts , the effectiveness of axonal regeneration and functional restoration was demonstrated .Methods:The acellular nerves derived from rabbits through chemically extracted processing were prepared and the ultrastructural organization was subsequently observed using the SEM .The nerve scaffolds were also seeded with BMSCs to construct tissue engineered transplants , af-ter culture in vitro , the ultrastructure of the integrated nerve grafts was observed .And then the xenogenic nerve grafts were employed to bridge sciatic nerve gaps in rats .After 8 weeks post

  19. Artificial ionospheric turbulence (review)

    International Nuclear Information System (INIS)

    This study is an analysis of artificial ionospheric turbulence (AIT) arising near the level at which a powerful wave is reflected with ordinary polarization. AIT is an inhomogeneous structure in the ionosphere with a size on the order of centimeters or tens of kilometers and with characteristic frequencies from a fraction of a hertz (aperiodic inhomogeneity) to several megahertz (plasma waves). The authors are primarily concerned with small-scale artificial ionospheric turbulence (SAIT), i.e., with inhomogeneities that are greatly extended along the geomagnetic field with transverse dimensions that are less than the wavelengths of the perturbing waves - the pumping waves (PW) - in a vacuum

  20. The autologus graft of epithelial tissue culture

    Directory of Open Access Journals (Sweden)

    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.

  1. An unusual formation of sciatic nerve

    OpenAIRE

    Sandhya Gunnal; Rajendra Wabale

    2013-01-01

    Sciatic nerve is the largest nerve and a branch of sacral plexus that controls hamstrings and all muscles of the lower limb below the knee. We are reporting a bilateral variant formation of the sciatic nerve found in a male human cadaver. The commencement of single sciatic nerve trunk formation was found to be in the lower gluteal region instead of the pelvic region. All the roots of the sciatic nerve, namely, the lumbosacral trunk (L4, L5), S1, S2, and S3 were observed to remain separate up ...

  2. Bilateral high division of sciatic nerve

    OpenAIRE

    K. Shwetha; Dakshayani KR

    2014-01-01

    Sciatic nerve is the thickest nerve in the body formed by the sacral plexus from L4 to S3 in the lesser pelvis. It emerges through the greater sciatic foramen below the piriformis and enter the gluteal region. Then the nerve passes on the back of the thigh and at the level of superior angle of popliteal fossa it terminates by dividing into tibial and common peroneal nerve. The knowledge of anatomical variations in the division of nerve is important for various surgical and anaesthetic procedu...

  3. Peroneal nerve palsy caused by intraneural ganglion

    International Nuclear Information System (INIS)

    A case of peroneal nerve palsy caused by an intraneural ganglion is presented. The cystic mass was located posterolateral to the lateral femoral condyle and extended along the common peroneal nerve distal to the origin of the peroneus longus muscle. The nerve was compressed in the narrow fibro-osseous tunnel against the fibula neck and the tight origin of the peroneus longus muscle. The nerve was decompressed by complete tumor excision and transection of the origin of the peroneus longus muscle. Full recovery of nerve function was obtained in 6 months. (orig.)

  4. Microsurgical anatomy of the abducens nerve.

    Science.gov (United States)

    Joo, Wonil; Yoshioka, Fumitaka; Funaki, Takeshi; Rhoton, Albert L

    2012-11-01

    The aim of this study is to demonstrate and review the detailed microsurgical anatomy of the abducens nerve and surrounding structures along its entire course and to provide its topographic measurements. Ten cadaveric heads were examined using ×3 to ×40 magnification after the arteries and veins were injected with colored silicone. Both sides of each cadaveric head were dissected using different skull base approaches to demonstrate the entire course of the abducens nerve from the pontomedullary sulcus to the lateral rectus muscle. The anatomy of the petroclival area and the cavernous sinus through which the abducens nerve passes are complex due to the high density of critically important neural and vascular structures. The abducens nerve has angulations and fixation points along its course that put the nerve at risk in many clinical situations. From a surgical viewpoint, the petrous tubercle of the petrous apex is an intraoperative landmark to avoid damage to the abducens nerve. The abducens nerve is quite different from the other nerves. No other cranial nerve has a long intradural path with angulations and fixations such as the abducens nerve in petroclival venous confluence. A precise knowledge of the relationship between the abducens nerve and surrounding structures has allowed neurosurgeon to approach the clivus, petroclival area, cavernous sinus, and superior orbital fissure without surgical complications. PMID:22334502

  5. Tractography of lumbar nerve roots: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Balbi, Vincent; Budzik, Jean-Francois; Thuc, Vianney le; Cotten, Anne [Hopital Roger Salengro, Service de Radiologie et d' Imagerie musculo-squelettique, Lille Cedex (France); Duhamel, Alain [Universite de Lille 2, UDSL, Lille (France); Bera-Louville, Anne [Service de Rhumatologie, Hopital Roger Salengro, Lille (France)

    2011-06-15

    The aims of this preliminary study were to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and fibre tracking (FT) of the lumbar nerve roots, and to assess potential differences in the DTI parameters of the lumbar nerves between healthy volunteers and patients suffering from disc herniation. Nineteen patients with unilateral sciatica related to posterolateral or foraminal disc herniation and 19 healthy volunteers were enrolled in this study. DTI with tractography of the L5 or S1 nerves was performed. Mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from tractography images. FA and MD values could be obtained from DTI-FT images in all controls and patients. The mean FA value of the compressed lumbar nerve roots was significantly lower than the FA of the contralateral nerve roots (p=0.0001) and of the nerve roots of volunteers (p=0.0001). MD was significantly higher in compressed nerve roots than in the contralateral nerve root (p=0.0002) and in the nerve roots of volunteers (p=0.04). DTI with tractography of the lumbar nerves is possible. Significant changes in diffusion parameters were found in the compressed lumbar nerves. (orig.)

  6. Cranial nerves XIII and XIV: nerves in the shadows

    OpenAIRE

    Bordoni, Bruno

    2013-01-01

    Bruno Bordoni,1 Emiliano Zanier21Don Carlo Gnocchi IRCCS, Department of Cardiology, Milan, 2Xamar Institute, Rosà, Vicenza, ItalyAbstract: It has been known for over a century that these cranial nerves exist, and that they are not typographical errors nor a sensational event reported in the medical literature. A number of scientific articles on anatomy highlight how textbooks on descriptive anatomy do not always consider variables such as differences related to the geographical are...

  7. Continuous peripheral nerve blocks in children.

    Science.gov (United States)

    Dadure, C; Capdevila, X

    2005-06-01

    In recent years, regional anaesthesia in children has generated increasing interest. Continuous peripheral nerve blocks have an important role in the anaesthetic arsenal, allowing effective, safe and prolonged postoperative pain management. Indications for continuous peripheral nerve blocks depend on benefits/risks analysis of each technique for each patient. The indications include surgery associated with intense postoperative pain, surgery requiring painful physical therapy, and complex regional pain syndrome. Continuous peripheral nerve blocks are usually performed under general anaesthesia or sedation, and require appropriate equipment in order to decrease the risk of nerve injury. New techniques, such as transcutaneous stimulation or ultrasound guidance, appear to facilitate nerve and plexus identification in paediatric patients. Nevertheless, continuous peripheral nerve block may mask compartment syndrome in certain surgical procedure or trauma. Finally, ropivacaine appears to be the best local anaesthetic for continuous peripheral nerve blocks in children, requiring low flow rate with low concentration of the local anaesthetic. PMID:15966500

  8. Influences of dehydration and rehydration on the lubrication properties of phospholipid polymer-grafted cross-linked polyethylene.

    Science.gov (United States)

    Yarimitsu, Seido; Moro, Toru; Kyomoto, Masayuki; Watanabe, Kenichi; Tanaka, Sakae; Ishihara, Kazuhiko; Murakami, Teruo

    2015-07-01

    Surface modification by grafting of biocompatible phospholipid polymer onto the surface of artificial joint material has been proposed to reduce the risk of aseptic loosening and improve the durability. Poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted cross-linked polyethylene (CLPE) has shown promising results for reducing wear of CLPE. The main lubrication mechanism for the PMPC layer is considered to be the hydration lubrication. In this study, the lubrication properties of PMPC-grafted CLPE were evaluated in reciprocating friction test with rehydration process by unloading in various lubricants. The start-up friction of PMPC-grafted CLPE was reduced, and the damage of PMPC layer was suppressed by rehydration in water or hyaluronic acid solutions. In contrast, the start-up friction of PMPC-grafted CLPE increased in fetal bovine serum solution, and the damage for PMPC layer was quite noticeable. Interestingly, the start-up friction of PMPC-grafted CLPE was reduced in fetal bovine serum solution containing hyaluronic acid, and the damage of the PMPC layer was suppressed. These results indicate that the rehydration by unloading and hyaluronic acid are elemental in maximizing the lubrication effect of hydrated PMPC layer. PMID:26036469

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

    Science.gov (United States)

    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

  10. Lipofibromatous Hamartoma of the Median Nerve with Long-term Follow-up.

    Directory of Open Access Journals (Sweden)

    Chung-Chen Hsu

    2005-02-01

    Full Text Available Lipofibromatous hamartoma is a rare, benign tumor that most often involves the mediannerve. A 16-year-old male with lipofibromatous hamartoma of the median nerve at the wristlevel is described. This patient was a child when the mass was first noted. Although therewere no symptoms or signs of carpal tunnel compression, the growth of the tumor was progressing.In addition to the release of the carpal tunnel, microsurgical intraneural dissectionwas done to preserve the thenar motor branch. Then segmental excision of the residual sensorycomponent with sural nerve grafting was performed. Subjectively the patient did notnotice the minor motor deficit, however, the patient did experience numbness of fingertipsafter surgery. There were no scars or trophic ulcers on fingertips at 3 years of follow-upregardless of the inadequate sensory return. Treatment of this benign tumor is still controversial.The relevant reports in the literature are reviewed.

  11. Production of artificial radioelements

    International Nuclear Information System (INIS)

    The techniques used in the production of artificial radioelements are described, with special emphasis on the following points: - nuclear reactions and use of reactors; - chemical separation methods and methods for enriching the activity of preparations; - protection of personnel and handling methods. (author)

  12. Artificial Left Ventricle

    CERN Document Server

    Ranjbar, Saeed; Meybodi, Mahmood Emami

    2014-01-01

    This Artificial left ventricle is based on a simple conic assumption shape for left ventricle where its motion is made by attached compressed elastic tubes to its walls which are regarded to electrical points at each nodal .This compressed tubes are playing the role of myofibers in the myocardium of the left ventricle. These elastic tubes have helical shapes and are transacting on these helical bands dynamically. At this invention we give an algorithm of this artificial left ventricle construction that of course the effect of the blood flow in LV is observed with making beneficiary used of sensors to obtain this effecting, something like to lifegates problem. The main problem is to evaluate powers that are interacted between elastic body (left ventricle) and fluid (blood). The main goal of this invention is to show that artificial heart is not just a pump, but mechanical modeling of LV wall and its interaction with blood in it (blood movement modeling) can introduce an artificial heart closed to natural heart...

  13. Observations of artificial satellites

    Directory of Open Access Journals (Sweden)

    A. MAMMANO

    1964-06-01

    Full Text Available The following publication gives the results of photographic
    observations of artificial satellites made at Asiago during the second
    and third year of this programme. The fixed camera technique and that
    with moving film (the latter still in its experimental stage have been used.

  14. Artificial intelligence within AFSC

    Science.gov (United States)

    Gersh, Mark A.

    1990-01-01

    Information on artificial intelligence research in the Air Force Systems Command is given in viewgraph form. Specific research that is being conducted at the Rome Air Development Center, the Space Technology Center, the Human Resources Laboratory, the Armstrong Aerospace Medical Research Laboratory, the Armamant Laboratory, and the Wright Research and Development Center is noted.

  15. Terahertz Artificial Dielectric Lens

    Science.gov (United States)

    Mendis, Rajind; Nagai, Masaya; Wang, Yiqiu; Karl, Nicholas; Mittleman, Daniel M.

    2016-03-01

    We have designed, fabricated, and experimentally characterized a lens for the THz regime based on artificial dielectrics. These are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. For example, the well-known dielectric property, the refractive index, which usually has a value greater than unity, can have a value less than unity in an artificial dielectric. For our lens, the artificial-dielectric medium is made up of a parallel stack of 100 μm thick metal plates that form an array of parallel-plate waveguides. The convergent lens has a plano-concave geometry, in contrast to conventional dielectric lenses. Our results demonstrate that this lens is capable of focusing a 2 cm diameter beam to a spot size of 4 mm, at the design frequency of 0.17 THz. The results further demonstrate that the overall power transmission of the lens can be better than certain conventional dielectric lenses commonly used in the THz regime. Intriguingly, we also observe that under certain conditions, the lens boundary demarcated by the discontinuous plate edges actually resembles a smooth continuous surface. These results highlight the importance of this artificial-dielectric technology for the development of future THz-wave devices.

  16. Artificial Gravity Research Plan

    Science.gov (United States)

    Gilbert, Charlene

    2014-01-01

    This document describes the forward working plan to identify what countermeasure resources are needed for a vehicle with an artificial gravity module (intermittent centrifugation) and what Countermeasure Resources are needed for a rotating transit vehicle (continuous centrifugation) to minimize the effects of microgravity to Mars Exploration crewmembers.

  17. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  18. Natural or Artificial Intelligence?

    Czech Academy of Sciences Publication Activity Database

    Havlík, Vladimír

    Plzeň: University of West Bohemia, 2013 - (Romportl, J.; Ircing, P.; Zackova, E.; Polak, M.; Schuster, R.), s. 15-27 ISBN 978-80-261-0275-5. [International Conference Beyond AI 2013. Plzeň (CZ), 12.11.2013-14.11.2013] Institutional support: RVO:67985955 Keywords : artificial intelligence * natural intelligence * artifact * natural process * intrinsic intentionality Subject RIV: AA - Philosophy ; Religion

  19. Artificial Intelligence and CALL.

    Science.gov (United States)

    Underwood, John H.

    The potential application of artificial intelligence (AI) to computer-assisted language learning (CALL) is explored. Two areas of AI that hold particular interest to those who deal with language meaning--knowledge representation and expert systems, and natural-language processing--are described and examples of each are presented. AI contribution…

  20. Micromachined Artificial Haircell

    Science.gov (United States)

    Liu, Chang (Inventor); Engel, Jonathan (Inventor); Chen, Nannan (Inventor); Chen, Jack (Inventor)

    2010-01-01

    A micromachined artificial sensor comprises a support coupled to and movable with respect to a substrate. A polymer, high-aspect ratio cilia-like structure is disposed on and extends out-of-plane from the support. A strain detector is disposed with respect to the support to detect movement of the support.

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

    Science.gov (United States)

    Negrin, Robert S

    2015-01-01

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

  2. Design and development of multilayer vascular graft

    Science.gov (United States)

    Madhavan, Krishna

    2011-07-01

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

  3. Improvement of polymer stability by radiation grafting

    International Nuclear Information System (INIS)

    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)

  4. Complement components of nerve regeneration conditioned fluid influence the microenvironment of nerve regeneration

    Directory of Open Access Journals (Sweden)

    Guang-shuai Li

    2016-01-01

    Full Text Available Nerve regeneration conditioned fluid is secreted by nerve stumps inside a nerve regeneration chamber. A better understanding of the proteinogram of nerve regeneration conditioned fluid can provide evidence for studying the role of the microenvironment in peripheral nerve regeneration. In this study, we used cylindrical silicone tubes as the nerve regeneration chamber model for the repair of injured rat sciatic nerve. Isobaric tags for relative and absolute quantitation proteomics technology and western blot analysis confirmed that there were more than 10 complement components (complement factor I, C1q-A, C1q-B, C2, C3, C4, C5, C7, C8ß and complement factor D in the nerve regeneration conditioned fluid and each varied at different time points. These findings suggest that all these complement components have a functional role in nerve regeneration.

  5. [Tracheal replacement grafts: current options].

    Science.gov (United States)

    Dulguerov, Pavel; Soccal, Paola M; Bouayed, Salim; Huber, Olivier; Pittet, Brigitte

    2011-10-01

    A critical review of publications on tracheal reconstruction is presented. The extent of the resection defect in terms of horizontal circumference or longitudinal extension determines the difficulty of the reconstruction. To allow a valid comparison, a classification of tracheal defects is proposed. The reconstruction materials can be subdivided into synthetic grafts, autografts, allografts, and bioengineering constructs. Reconstruction of tracheal defects greater than half of the tracheal length was not possible until recently. Numerous publications on animal experimental techniques, and rare human case reports show few successful outcomes. During the last five years, new reconstructive options have emerged: autograft of composite flaps mimicking tracheal architecture and bioengineered tracheal constructs. PMID:22046681

  6. An experimental study on anatomical observation and functional foundation of construction of "abdominal wall-spinal cord center-bladder" artificial reflex arc in SD rat%构建SD大鼠"腹壁反射-脊髓中枢-膀胱"人工反射弧的解剖学观察和功能基础的实验研究

    Institute of Scientific and Technical Information of China (English)

    梁耿祺; 周兴; 潘建刚; 史群伟

    2009-01-01

    traced to the intervertebral hole direction until its ventral root and dor-sal root were found. The netive potential of T13 nerve root was recorded by stimulating The abdominal wall, while the TI3 nerve rent's spentaneo neural discharge was recorded as the comparison without stimulation. There were 4 pairs sacral nervos. The ventral root and dorsal root of $2 spinal nerve were dissoeted under microscope. The active poten-tial of plexus vesica and the myeelectricity of bladder smooth muscle were reenrded by stimulating S2 nerve .root, while the S2 nerve root's spontaneous neural discharge was recorded as the comparison without stimulation. Then, it was a-chieved by intradural microanastomosis of the left T13 ventral root was anastomosed under microscope to S2 ventral root by autogenous nerve grafting intraduraly, with the left T13 dorsal root remaining intact. Results In anatomy,the diameter of T13' s ventral root was about 0.4ram,and the diameter of S2 ' s ventral root was about O. 3mm. Both of diameters were close,and both of ventral roots located at ventralis medialis and had no spinal ganglion. In func-tion, the TI3 intercostal nerve mainly dominated the abdominal wall's feeling and the movement,and the S2 nerve mainly dominated bladder function. Both of them can produce the similar figures by stimulation. So,it can be achieved by intradural microanastomosis of the left TI3 ventral root was anastomosed under microscope to S2 ventral root by an-togenous nerve grafting intraduraly, with the left TI3 dorsal root remaining intact. Then, "the abdominal wall-spinal cord center-bladder" artificial reflex was constructed. Conclusions The anatomical and functional characteris-tic of TI3 and S2 nerve root is the foundation to eoastruct "the abdominal wall-spinal cord center-bladder" artifi-cial reflex in SD rat.

  7. The longitudinal epineural incision and complete nerve transection method for modeling sciatic nerve injury

    Directory of Open Access Journals (Sweden)

    Xing-long Cheng

    2015-01-01

    Full Text Available Injury severity, operative technique and nerve regeneration are important factors to consider when constructing a model of peripheral nerve injury. Here, we present a novel peripheral nerve injury model and compare it with the complete sciatic nerve transection method. In the experimental group, under a microscope, a 3-mm longitudinal incision was made in the epineurium of the sciatic nerve to reveal the nerve fibers, which were then transected. The small, longitudinal incision in the epineurium was then sutured closed, requiring no stump anastomosis. In the control group, the sciatic nerve was completely transected, and the epineurium was repaired by anastomosis. At 2 and 4 weeks after surgery, Wallerian degeneration was observed in both groups. In the experimental group, at 8 and 12 weeks after surgery, distinct medullary nerve fibers and axons were observed in the injured sciatic nerve. Regular, dense myelin sheaths were visible, as well as some scarring. By 12 weeks, the myelin sheaths were normal and intact, and a tight lamellar structure was observed. Functionally, limb movement and nerve conduction recovered in the injured region between 4 and 12 weeks. The present results demonstrate that longitudinal epineural incision with nerve transection can stably replicate a model of Sunderland grade IV peripheral nerve injury. Compared with the complete sciatic nerve transection model, our method reduced the difficulties of micromanipulation and surgery time, and resulted in good stump restoration, nerve regeneration, and functional recovery.

  8. A review of 155 extra-anatomic bypass grafts.

    OpenAIRE

    Foster, M.C.; Mikulin, T; Hopkinson, B R; Makin, G. S.

    1986-01-01

    Extra-anatomic bypass grafting has been used as treatment for patients with aorto-iliac disease who were considered unfit for aortic surgery. Eighty five percent of the patients had ischaemic pain at rest or skin necrosis. One hundred and three femorofemoral (FF) grafts, 40 axillounifemoral and 12 axillobifemoral grafts were performed. Femoropopliteal extension grafts were performed in 39 cases. The three year cumulative graft patency rate was 69% for FF grafts and 48% for both types of axill...

  9. PREPARATION AND APPLICATION OF DIMER ACID/LIGNIN GRAFT COPOLYMER

    OpenAIRE

    Run Fang; Xiansu Cheng; Wu-shi Lin

    2011-01-01

    Dimer acid (DA) was grafted onto lignin (EHL) to form a graft copolymer DA-g-EHL. The selection of the reaction type and the optimization of the reaction conditions for the grafting reaction were conducted through orthogonal and single factor experiments. FT-IR and thermal analysis were used to characterize the graft product. It was found that, compared with free radical grafting, DA can be grafted onto EHL more effectively by ester condensation with strongly acidic cation exchange resin as a...

  10. Influence of ischemia before vein grafting on early hyperplasia of the graft and the dynamic changes of the intima after grafting

    Directory of Open Access Journals (Sweden)

    Zou RongJiang

    2012-09-01

    Full Text Available Abstract Background To investigate both the influence of ischemia before grafting on early hyperplasia of the vein grafts, and the dynamic changes of the intima after grafting in a rabbit model of vein graft disease. Methods We performed paired vein graft experiments under different ischemic conditions (15 vs. 60 min; 15 vs. 90 min in the neck of the rabbits and compared the differences between the grafts. Clopidogrel, an anti-platelet agent, was administered before and after surgery. Twenty-eight days after the grafting procedure, the veins were evaluated microscopically. The dynamic changes of the intima after grafting were evaluated by scanning electron microscopy over time. Results The vein grafts subjected to 60- or 90-min ischemia exhibited no differences compared to those subjected to 15-min ischemia in terms of the mean thickness of the intimal, medial, and adventitial layers of the graft. Similarly, there was no difference in the Ki-67 labeling index (proliferation marker between the vein grafts. Vein grafts with 15-min ischemia lost endothelial cells (ECs but healed by 3 days post graft, whereas vein grafts with 90-min ischemia suffered serious EC loss, which was restored with new ECs during days 2 to 14 post graft. Conclusions Ninety-minute ischemia before vein grafting can cause serious EC loss, but does not increase early intimal hyperplasia when clopidogrel is administered. Protecting the vein from ischemia and reperfusion injury preserves ECs.

  11. Haemangiopericytoma of the trigeminal nerve

    International Nuclear Information System (INIS)

    A 41-year-old man presented with a 4-year history of progressive right-sided diplopia on lateral gaze and right nasolabial paraesthesia. A CT revealed minor bone erosion of Meckel's cave and of the right petrous apex by a uniformly enhancing lesion at the base of the skull. Magnetic resonance imaging on three occasions over 2 years showed tumour, measuring 4 cm in diameter, with features suggestive of a trigeminal neuroma. At surgery the lesion had the macroscopic appearance of a giant schwannoma. Histopathological findings were that of a meningeal haemangiopericytoma (HPC) of the trigeminal nerve. lntracranial HPC are rare and aggressive tumours of the central nervous system. They usually arise from the falx, tentorium and dural sinuses. The present case is unique as it originates from a cranial nerve. Copyright (2001) Blackwell Science Pty Ltd

  12. The nerves around the shoulder

    International Nuclear Information System (INIS)

    Neuropathies of the shoulder are considered to be entrapment syndromes. They are relatively common, accounting for about 2% of cases of sport-related shoulder pain. Many instances involve suprascapular neuropathy, but the clinical diagnosis is often delayed because of nonspecific symptoms. Classically, EMG is the gold standard investigation but MRI currently reveals muscular abnormality in 50% of cases. Muscle edema, the most characteristic symptom, is nonspecific. In general, the topography of edema, the presence of a lesion compressing the nerve and clinical history contribute to the diagnosis. Although atrophy and fatty degeneration may persist after the disappearance of edema, they are rarely symptomatic. The main differential diagnosis is Parsonage–Turner syndrome. Evidence of a cyst pressing on a nerve may prompt puncture-infiltration guided by ultrasonography or CT-scan

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

    International Nuclear Information System (INIS)

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Yuki [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan)]. E-mail: wada.yuki@jaea.go.jp; Seko, Noriaki [Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Nagasawa, Naotsugu [Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Tamada, Masao [Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Kasuya, Ken-ichi [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Mitomo, Hiroshi [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan)

    2007-06-15

    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.

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

    Science.gov (United States)

    Moufarrej, Andrew; Tordoir, Jan; Mees, Barend

    2016-03-01

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

  17. Introduction to Artificial Neural Networks

    DEFF Research Database (Denmark)

    Larsen, Jan

    1999-01-01

    The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks.......The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks....

  18. Inflatable artificial sphincter - series (image)

    Science.gov (United States)

    An artificial urinary sphincter is used to treat stress incontinence in men that is caused by urethral dysfunction such ... An artificial sphincter consists of three parts: a cuff that fits around the bladder neck a pressure regulating balloon ...

  19. Rehabilitation instruction after intervertebral bone graft internal fixation of lumbar spondylolisthesis%腰椎滑脱椎体间植骨固定术后的康复指导

    Institute of Scientific and Technical Information of China (English)

    张晋亭

    2003-01-01

    @@ BACKGROUND:Internal fixation of lumbral spondylolisthesis has resolved the problem caused by vertebral translocation and postoperative rehabilitation instruction can prevent moving of bone.Directed to different stages,suitable posture and rehabilitation function exercises can effectively prevent loose intervertebral grafted bone and adhesion of nerve root.

  20. Neuralgias of the Trigeminal Nerve

    OpenAIRE

    Gordon, Allan S

    2000-01-01

    Practitioners are often presented with patients who complain bitterly of facial pain. The trigeminal nerve is involved in four conditions that are sometimes mixed up. The four conditions - trigeminal neuralgia, trigeminal neuropathic pain, postherpetic neuralgia and atypical facial pain - are discussed under the headings of clinical features, differential diagnosis, cause and treatment. This article should help practitioners to differentiate one from the other and to manage their care.