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Sample records for artificial nerve grafts

  1. Dog sciatic nerve gap repaired by artificial tissue nerve graft

    Institute of Scientific and Technical Information of China (English)

    GU Xiaosong; ZHANG Peiyun; WANG Xiaodong; DING Fei; PENG Luping; CHENG Hongbing

    2003-01-01

    The feasibility of repairing dog sciatic nerve damage by using a biodegradable artificial tissue nerve graft enriched with neuroregenerating factors is investigated. The artificial nerve graft was implanted to a 30 mm gap of the sciatic nerve damage in 7 dogs. The dogs with the same nerve damage that were repaired by interposition of the autologous nerve or were given no treatment served as control group 1 or 2, respectively. The observations include gross and morphological observations, immune reaction, electrophysiological examination, fluorescence tracing of the neuron formation and the number of the neurons at the experimental sites, etc. Results showed that 6 months after the implantation of the graft, the regenerated nerve repaired the damage of the sciatic nerve without occurrence of rejection and obvious inflammatory reaction in all 7 dogs, and the function of the sciatic nerve recovered with the nerve conduction velocity of (23.91±11.35)m/s. The regenerated neurons and the forming of axon could be observed under an electron microscope. This proves that artificial tissue nerve graft transplantation can bridge the damaged nerve ends and promote the nerve regeneration.

  2. 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.

  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

    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

    2014-01-01

    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 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

  4. 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...

  5. Biological and artificial nerve conduit for repairing peripheral nerve defect

    Institute of Scientific and Technical Information of China (English)

    Xuetao Xie; Changqing Zhang

    2006-01-01

    OBJECTIVE: Recently, with the development of biological and artificial materials, the experimental and clinical studies on application of this new material-type nerve conduit for treatment of peripheral nerve defect have become the hotspot topics for professorial physicians.DATA SOURCES: Using the terms "nerve conduits, peripheral nerve, nerve regeneration and nerve transplantation" in English, we searched Pubmed database, which was published during January 2000 to June 2006, for the literatures related to repairing peripheral nerve defect with various materials. At the same time, we also searched Chinese Technical Scientific Periodical Database at the same time period by inputting" peripheral nerve defect, nerve repair, nerve regeneration and nerve graft" in Chinese.STUDY SELECTION: The materials were firstly selected, and literatures about study on various materials for repairing peripheral nerve defect and their full texts were also searched. Inclusive criteria: nerve conduits related animal experiments and clinical studies. Exclusive criteria: review or repetitive studies.DATA EXTRACTION: Seventy-nine relevant literatures were collected and 30 of them met inclusive criteria and were cited.DATA SYNTHESTS: Peripheral nerve defect, a commonly seen problem in clinic, is difficult to be solved. Autogenous nerve grafting is still the gold standard for repairing peripheral nerve defect, but because of its application limitation and possible complications, people studied nerve conduits to repair nerve defect. Nerve conduits consist of biological and artificial materials.CONCLUSION: There have been numerous reports about animal experimental and clinical studies of various nerve conduits, but nerve conduit, which is more ideal than autogenous nerve grafting, needs further clinical observation and investigation.

  6. 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.

  7. Anatomical characteristics and histocompatibility of artificial nerve grafts of human-hair keratin%人发角蛋白非神经移植材料的解剖学特点及组织相容性

    Institute of Scientific and Technical Information of China (English)

    王进; 邹云雯; 罗学勤

    2009-01-01

    BACKGROUND: Artificial nerve grafts of human hair keratin are a kind of biological products. It has low antigenicity, absorbability and stimulation to nerve fiber growth following specific biochemistry. It is hoped to have better effect than other artificial nerve grafts.  OBJECTIVE: To investigate the anatomy and histocompatibility of artificial nerve grafts of the human-hair keratin, and to observe its effects on the repair of peripheral nerves.   DESIGN, TIME AND SETTING: Randomized, controlled, animal experiment. The study was performed at the Animal Central Laboratory of Affiliated Hospital of Qingdao University Medical College between November 2006 and June 2008. MATERIALS: Artificial nerve grafts of human hair keratin is a compound of human hair processed by specific controlled biochemistry based on ground substance, embedded with a layer of biological membrane. It has low antigenicity, absorbability and stimulation to nerve fiber growth following specific biochemistry. METHODS: Eighteen Wistar rats were randomly divided into three groups. The sciatic nerve, 10 mm, was removed and transplanted with human-hair keratin graft, skeletal muscle and untreated hair, respectively. MAIN OUTCOME MEASURES: The characteristics of histomorphology and anatomy were observed at 8, 12, 24 weeks after the surgery. RESULTS: White tissues appeared between the broken ends of the sciatic nerve at 8 post-operative week in the graft group, and appeared in the graft space in human-hair keratin at the 12th week. At the 24th week, a large amount of infantile myelinated nerve fibers were observed under optical microscope regenerating around the human hair, which was partially degraded and absorbed. Schwann cells were observed under an electron microscope and myelinization.   CONCLUSION: The artificial nerve grafts of the human-hair keratin are well compatible with the body tissues, and could induce nerve regeneration.%背景:人发角蛋白非神经移植材料是一种生物性

  8. 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

  9. Nerve repair and cable grafting for facial paralysis.

    Science.gov (United States)

    Humphrey, Clinton D; Kriet, J David

    2008-05-01

    Facial nerve injury and facial paralysis are devastating for patients. Although imperfect, primary repair is currently the best option to restore facial nerve function. Cable, or interposition, nerve grafting is an acceptable alternative when primary repair is not possible. Several donor nerves are at the surgeon's disposal. Great auricular, sural, or medial and lateral antebrachial cutaneous nerves are all easily obtained. Both primary repair and interposition grafting typically result in better facial function than do other dynamic and static rehabilitation strategies. Proficient anastomotic technique and, when necessary, selection of an appropriate interposition graft will optimize patient outcomes. Promising research is under way that will enhance future nerve repair and grafting efforts.

  10. 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.

  11. Poly(DL-lactide-epsilon-caprolactone) nerve guides perform better than autologous nerve grafts

    NARCIS (Netherlands)

    DenDunnen, WFA; VanderLei, B; Schakenraad, JM; Stokroos, [No Value; Blaauw, E; Pennings, AJ; Robinson, PH; Bartels, H.

    1996-01-01

    The aim of this study was to compare the speed and quality of nerve regeneration after reconstruction using a biodegradable nerve guide or an autologous nerve graft. We evaluated nerve regeneration using light microscopy, transmission electron microscopy and morphometric analysis. Nerve regeneration

  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. Biofabrication and testing of a fully cellular nerve graft.

    Science.gov (United States)

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

    2013-12-01

    Rupture of a nerve is a debilitating injury with devastating consequences for the individual's quality of life. The gold standard of repair is the use of an autologous graft to bridge the severed nerve ends. Such repair however involves risks due to secondary surgery at the donor site and may result in morbidity and infection. Thus the clinical approach to repair often involves non-cellular solutions, grafts composed of synthetic or natural materials. Here we report on a novel approach to biofabricate fully biological grafts composed exclusively of cells and cell secreted material. To reproducibly and reliably build such grafts of composite geometry we use bioprinting. We test our grafts in a rat sciatic nerve injury model for both motor and sensory function. In particular we compare the regenerative capacity of the biofabricated grafts with that of autologous grafts and grafts made of hollow collagen tubes by measuring the compound action potential (for motor function) and the change in mean arterial blood pressure as consequence of electrically eliciting the somatic pressor reflex. Our results provide evidence that bioprinting is a promising approach to nerve graft fabrication and as a consequence to nerve regeneration.

  15. Functional assessment of sciatic nerve reconstruction : Biodegradable poly (DLLA-epsilon-CL) nerve guides versus autologous nerve grafts

    NARCIS (Netherlands)

    Meek, MF; Dijkstra, [No Value; Den Dunnen, WFA; Ijkema-Paassen, J; Schakenraad, JM; Gramsbergen, A; Robinson, PH

    1999-01-01

    The aim of this study was to compare functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with modified denatured muscle tissue (MDMT), or an autologous nerve graft. We evaluated nerve recovery using walking track analysis (measurement of the scia

  16. 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...

  17. Biodegradable p(DLLA-epsilon-CL) nerve guides versus autologous nerve grafts : Electromyographic and video analysis

    NARCIS (Netherlands)

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

    2001-01-01

    The aim of this study was to evaluate the functional effects of bridging a gap in the sciatic nerve of the rat with either a biodegradable copolymer of (DL)-lactide and epsilon -caprolactone [p(DLLA-epsilon -CL)] nerve guide or an autologous nerve graft. Electromyograms (EMGs) of the gastrocnemius (

  18. 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.

  19. 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.

  20. Tissue-Engineered Nanofibrous Nerve Grafts for Enhancing the Rate of Nerve Regeneration

    Science.gov (United States)

    2015-10-01

    Matrices Derived from Schiff Base Derivative for Tissue Engineering Applications . Jaiswal D., James, R., Shelke N.B., Harmon M.D., Brown J. L., Hussain F...BMSCs seeded on nerve grafts. Based on our current progress with the in vivo animal studies, we have observed that the autograft group yielded better...coaptation of the proximal and distal stump when the nerve gap is ɜmm and when the nerve gap is >4mm, application of an autograft, in which a patient’s own

  1. To fabricate artificial nerves with tissue engineering methods

    Institute of Scientific and Technical Information of China (English)

    程飚; 陈峥嵘

    2002-01-01

    To fabricate artificial nerves with tissue engineering methods in vitro. Methods: Schwann cells (SCs) were cultured and seeded on polyglactin 910 fibers wrapped by biomembrane coated with rat tail glue and laminin for 2 weeks. The absorbability on the scaffolds, growth and migration of SCs were assessed with a light microscope, a scanning electron microscope and a transmission electron microscope. Results: SCs could migrate and proliferate on polyglactin 910 fibers. They were well distributed between scaffolds and absorbed on surface of scaffolds and formed a bungner band, on which SCs produced more matrices. SCs seeded on the biomembrane could also grow well. Axon regeneration in the distal nerve stump was observed at 8 weeks. Conclusions: Adult SCs can be expanded on coated fibers and biomembrane. Three-dimensional scaffold of SCs has the basic characteristics of artificial nerves. These findings offer a novel method to fabricate artificial nerves with tissue engineering methods for repairing defected long nerves.

  2. Comparison of rabbit facial nerve regeneration in nerve growth factor-containing silicone tubes to that in autologous neural grafts.

    Science.gov (United States)

    Spector, J G; Lee, P; Derby, A; Roufa, D G

    1995-11-01

    Previous reports suggest that nerve growth factor (NGF) enhanced nerve regeneration in rabbit facial nerves. We compared rabbit facial nerve regeneration in 10-mm silicone tubes prefilled with NGF or cytochrome C (Cyt C), bridging an 8-mm nerve gap, to regeneration of 8-mm autologous nerve grafts. Three weeks following implantation, NGF-treated regenerates exhibited a more mature fascicular organization and more extensive neovascularization than Cyt C-treated controls. Morphometric analysis at the middle of the tube of 3- and 5-week regenerates revealed no significant difference in the mean number of myelinated or unmyelinated axons between NGF- and Cyt C-treated implants. However, when the numbers of myelinated fibers in 5-week regenerates were compared to those in their respective preoperative controls, NGF-treated regenerates had recovered a significantly greater percentage of myelinated axons than Cyt C-treated implants (46% versus 18%, respectively). The number of regenerating myelinated axons in the autologous nerve grafts at 5 weeks was significantly greater than the number of myelinated axons in the silicone tubes. However, in the nerve grafts the majority of the axons were found in the extrafascicular connective tissue (66%). The majority of these myelinated fibers did not find their way into the distal nerve stump. Thus, although the number of regenerating myelinated axons within the nerve grafts is greater than that of axons within silicone tube implants, functional recovery of autologous nerve graft repairs may not be superior to that of intubational repairs.

  3. Using an end-to-side interposed sural nerve graft for facial nerve reinforcement after vestibular schwannoma resection. Technical note.

    Science.gov (United States)

    Samii, Madjid; Koerbel, Andrei; Safavi-Abbasi, Sam; Di Rocco, Federico; Samii, Amir; Gharabaghi, Alireza

    2006-12-01

    Increasing rates of facial and cochlear nerve preservation after vestibular schwannoma surgery have been achieved in the last 30 years. However, the management of a partially or completely damaged facial nerve remains an important issue. In such a case, several immediate or delayed repair techniques have been used. On the basis of recent studies of successful end-to-side neurorrhaphy, the authors applied this technique in a patient with an anatomically preserved but partially injured facial nerve during vestibular schwannoma surgery. The authors interposed a sural nerve graft to reinforce the facial nerve whose partial anatomical continuity had been preserved. On follow-up examinations 18 months after surgery, satisfactory cosmetic results for facial nerve function were observed. The end-to-side interposed nerve graft appears to be a reasonable alternative in cases of partial facial nerve injury, and might be a future therapeutic option for other cranial nerve injuries.

  4. Clinical results and thoughts on sensory nerve repair by autologous vein graft in emergency hand reconstruction.

    Science.gov (United States)

    Risitano, G; Cavallaro, G; Merrino, T; Coppolino, S; Ruggeri, F

    2002-05-01

    Lesions of the digital and other sensory nerves in the hand are common. Based on experimental studies on vein graft as a support for peripheral nerve regeneration, the Authors have been using a simple vein graft to bridge sensory nerve gaps when treating acute hand injuries. This is a retrospective study on the results of 22 sensory nerves repaired using vein grafts in cases in which primary suture was not feasible, in emergency hand reconstruction. Patients were informed that a secondary nerve graft could possibly be necessary in the future. Patients were reviewed by two independent observers at least one year after repair and evaluated using the Highest scale as modified by MacKinnon & Dellon. Evaluation chart included influence of repair on rehabilitation program and presence of painful neuromas and scars as well as patient satisfaction. Results were classified according to Sakellarides and 20/22 were classified as very good or good. Cases classified as poor were satisfied and no secondary nerve grafting has been carried out. Rehabilitation of the associated lesions (tendon lacerations or bone and soft tissue damage) was not influenced by the nerve repair and no painful neuroma was reported in the series. In conclusion, since the literature shows unsatisfactory results in repair of digital nerves with nerve grafts, since it's been demonstrated that an unrepaired sensory nerve leads to painful scar and painful neuroma and since we are reluctant to use nerve grafts in emergency procedures, we recommend this simple method because it is easy, low-cost and effective.

  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. Acellular allogeneic nerve grafting combined with bone marrow mesenchymal stem cell transplantation for the repair of long-segment sciatic nerve defects: biomechanics and validation of mathematical models

    Directory of Open Access Journals (Sweden)

    Ya-jun Li

    2016-01-01

    Full Text Available We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects. To test this, we established rabbit models of 30 mm sciatic nerve defects, and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells. We compared the tensile properties, electrophysiological function and morphology of the damaged nerve in each group. Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell transplantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone, and produced similar results to those observed with the autograft. These findings confirm that a chemically extracted acellular allogeneic nerve graft combined with transplantation of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects.

  7. Assessment of in vivo behavior of polymer tube nerve grafts simultaneously with the peripheral nerve regeneration process using scanning electron microscopy technique.

    Science.gov (United States)

    Szarek, Dariusz; Marycz, Krzysztof; Laska, Jadwiga; Bednarz, Paulina; Jarmundowicz, Włodzimierz

    2013-01-01

    In this study, scanning electron microscopy (SEM) has been applied for instantaneous assessment of processes occurring at the site of regenerating nerve. The technique proved to be especially useful when an artificial implant should have been observed but have not yet been extensively investigated before for assessment of nerve tissue. For in vivo studies, evaluation of implant's morphology and its neuroregenerative properties is of great importance when new prototype is developed. However, the usually applied histological techniques require separate and differently prepared samples, and therefore, the results are never a 100% comparable. In our research, we found SEM as a technique providing detailed data both on an implant behavior and the nerve regeneration process inside the implant. Observations were carried out during 12-week period on rat sciatic nerve injury model reconstructed with nerve autografts and different tube nerve grafts. Samples were analyzed with haematoxylin-eosin (HE), immunocytochemical staining for neurofillament and S-100 protein, SEM, TEM, and the results were compared. SEM studies enabled to obtain characteristic pictures of the regeneration process similarly to TEM and histological studies. Schwann cell transformation and communication as well as axonal outgrowth were identified, newly created and matured axons could be recognized. Concurrent analysis of biomaterial changes in the implant (degradation, collapsing of the tube wall, migration of alginate gel) was possible. This study provides the groundwork for further use of the described technique in the nerve regeneration studies.

  8. 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.

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

    Institute of Scientific and Technical Information of China (English)

    Cheng-dong Piao; Kun Yang; Peng Li; Min Luo

    2015-01-01

    In the repair of peripheral nerve injury using autologous or synthetic nerve grafting, the mag-nitude 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. There-fore, in the present study, we established three-dimensional ifnite element models of sciatic nerve defects repaired by autologous nerve grafts. Using PRO E 5.0 ifnite 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 ifndings indicate that three-dimensional ifnite element simulation is a feasible method for analyzing stress and displacement at the anas-tomosis after autologous nerve grafting.

  10. 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

    Directory of Open Access Journals (Sweden)

    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.

  11. Repair of multiple cervical root avulsion with sural nerve graft.

    Science.gov (United States)

    Hsu, Sanford P C; Shih, Yang-Hsin; Huang, Ming-Chao; Chuang, Tien-Yow; Huang, Wen-Cheng; Wu, Hsiu-Mei; Lin, Pei-Hsin; Lee, Liang-Shong; Cheng, Henrich

    2004-09-01

    To obtain easier access to avulsed roots in the intradural space for patients suffering cervical root avulsion, the authors of this study developed a novel repair method. This involves using nerve grafts to bridge corresponding segments of the spinal cord and the trunk or cord level of the plexus, respectively, in two surgical stages. All eight patients admitted to this study received pre- and post-operative workups of electrophysiological evaluations and muscle power grading through Medical Research Council (MRC) scores. The degrees of impairment were also graded according to a modified version of Dumitru's and Wilbourn's scale (mild = 1; moderate = 2; severe = 3). The preoperative versus post-operative differences in the severity of the injuries and in the grading of the target muscle power were calculated according to the Wilcoxon signed-rank test. The preoperative degree of the severity of the injuries, as measured by electromyography (EMG), was 3.00 +/- 0.00 (mean +/- S.D.). The post-operative result was 2.125 +/- 0.641. Significant change took place after repair (P = 0.0313). Moreover, although little improvement was observed in the triceps, brachioradialis (BR), extensor carpi radialis (ECR), flexor digitorum profundus (FDP) and intrinsic hand muscles, the MRC grading showed significant yet not prominent motor recovery in the deltoid and biceps brachii (both P = 0.0313). We were impressed that the initial significant statistical results of differences in pre- and post-operative severity of the injuries and muscle power grading, demonstrated that regeneration does occur with this repair strategy.

  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-.

    Directory of Open Access Journals (Sweden)

    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. A NEW METHOD TO SHORTEN THE LENGTH OF NERVE GRAFT AND TO SECURE THE NERVE REPAIR (AN INTRAOPERATIVE EXPERIENCE BASED ON 30 CASES OF OBSTETRICAL BRACHIAL PLEXUS PALSY)

    OpenAIRE

    2012-01-01

    Purpose: to compare the result of using a stay stitch to bridge the nerve gaps with repair the nerve gap without using a stay stitch, to compare both ways on the length of graft, number of grafts and number of cables per graft. Methods: a comparative study between 2 groups of babies with OBPP in which each group consists of 15 infants. In all the patients in both groups, neuroma excision and nerve grafting was indicated. In group (A) the defects were measured directly after neuroma excision w...

  15. 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.

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

    Science.gov (United States)

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

    2014-12-01

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

  18. 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.

  19. 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.

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

    NARCIS (Netherlands)

    den Dunnen, WFA; Meek, MF

    2001-01-01

    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-y-capr

  2. A vascularized nerve graft substitute generated in a chamber bioreactor- A preliminary report

    Directory of Open Access Journals (Sweden)

    Murat Sinan Engin

    2016-08-01

    Conclusion: According to the literature review, this is the first achievement of engineering a nerve graft substitute containing vascularized Schwann cells. Therefore, it is believed this study has yielded significant preliminary results, providing a basis for future studies. [Hand Microsurg 2016; 5(2.000: 62-69

  3. Repair of ocular-oral synkinesis of postfacial paralysis using cross-facial nerve grafting.

    Science.gov (United States)

    Zhang, Bo; Yang, Chuan; Wang, Wei; Li, Wei

    2010-08-01

    We present the surgical techniques and results of cross-facial nerve grafting that have been developed in the repair of ocular-oral synkinesis after facial paralysis. Eleven patients with ocular-oral synkinesis after facial paralysis underwent the cross-facial nerve grafting with facial nerve transposition at a tertiary academic hospital between 2003 and 2009. The patient selection for the study was based on the degree of disfigurement and facial function parameter rating using the Toronto Facial Grading System. The procedures used were surgeries done in two stages. All cases were followed up for 2 months to 6 years after the second surgery. The degree of improvement was evaluated at 6 to 7 months after the procedures. Six of the patients were followed up for more than 2 years after the stage-two surgery and demonstrated significant reduction in the ocular-oral synkinetic movements. The Toronto Facial Grading System scores from the postoperative follow-ups increased an average of 16 points (28%), and the patients had achieved symmetrical facial movement. We concluded that cross-facial nerve grafting with facial nerve branch transposition is effective and can be considered as an option for the repair of ocular-oral synkinesis after facial paralysis in select patients.

  4. Combining peripheral nerve grafts and chondroitinase promotes functional axonal regeneration in the chronically injured spinal cord.

    Science.gov (United States)

    Tom, Veronica J; Sandrow-Feinberg, Harra R; Miller, Kassi; Santi, Lauren; Connors, Theresa; Lemay, Michel A; Houlé, John D

    2009-11-25

    Because there currently is no treatment for spinal cord injury, most patients are living with long-standing injuries. Therefore, strategies aimed at promoting restoration of function to the chronically injured spinal cord have high therapeutic value. For successful regeneration, long-injured axons must overcome their poor intrinsic growth potential as well as the inhibitory environment of the glial scar established around the lesion site. Acutely injured axons that regenerate into growth-permissive peripheral nerve grafts (PNGs) reenter host tissue to mediate functional recovery if the distal graft-host interface is treated with chondroitinase ABC (ChABC) to cleave inhibitory chondroitin sulfate proteoglycans in the scar matrix. To determine whether a similar strategy is effective for a chronic injury, we combined grafting of a peripheral nerve into a highly relevant, chronic, cervical contusion site with ChABC treatment of the glial scar and glial cell line-derived neurotrophic factor (GDNF) stimulation of long-injured axons. We tested this combination in two grafting paradigms: (1) a peripheral nerve that was grafted to span a chronic injury site or (2) a PNG that bridged a chronic contusion site with a second, more distal injury site. Unlike GDNF-PBS treatment, GDNF-ChABC treatment facilitated axons to exit the PNG into host tissue and promoted some functional recovery. Electrical stimulation of axons in the peripheral nerve bridge induced c-Fos expression in host neurons, indicative of synaptic contact by regenerating fibers. Thus, our data demonstrate, for the first time, that administering ChABC to a distal graft interface allows for functional axonal regeneration by chronically injured neurons.

  5. Acellular allogeneic nerve grafting combined with bone marrow mesenchymal stem cell transplantation for the repair of long-segment sciatic nerve defects:biomechanics and validation of mathematical models

    Institute of Scientific and Technical Information of China (English)

    Ya-jun Li; Bao-lin Zhao; Hao-ze Lv; Zhi-gang Qin; Min Luo

    2016-01-01

    We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects. To test this, we established rabbit models of 30 mm sciatic nerve defects, and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells. We compared the tensile properties, electrophysiological function and morphology of the damaged nerve in each group. Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell trans-plantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone, and produced similar results to those observed with the autograft. These ifndings conifrm that a chemically extracted acellular allogeneic nerve graft combined with transplanta-tion of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects.

  6. Intrinsic hand muscle reinnervation by median-ulnar end-to-side bridge nerve graft: case report.

    Science.gov (United States)

    Magdi Sherif, M; Amr, Adel H

    2010-03-01

    Recovery of either the motor or sensory functions has not been consistently achieved in upper extremity end-to-side neurorrhaphy; this technique was only indicated when more conventional nerve repair was not possible. In most studies, the whole median or ulnar nerve was used for end-to-side neurotization. In this report, we present 4 cases of high-median or ulnar nerve laceration in which a nerve graft was placed end-to-side between the median and ulnar motor fascicles close to the wrist. At 4 months after surgery, 3 of 4 patients began to recover active movement of the affected small muscles of the hand. EMG and nerve conduction studies confirmed that nerve conduction was through the nerve grafts.

  7. Reinnervation of Paralyzed Muscle by Nerve-Muscle-Endplate Band Grafting

    Science.gov (United States)

    2015-10-01

    COVERED 15 Sep 2014-14 Sep 2015 4. TITLE AND SUBTITLE Reinnervation of Paralyzed Muscle by Nerve-Muscle- Endplate Band Grafting 5a. CONTRACT NUMBER... muscular tissues in Goals 2 and 3 is in years 3 & 4. • Major Activities: In the past year, we have performed the following major...the right SM was outlined and a muscular defect (recipient bed) with the same dimensions as the NMEG (Figs 1 & 2) was made in the NMZ of the

  8. 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.

  9. Transection of peripheral nerves, bridging strategies and effect evaluation

    NARCIS (Netherlands)

    IJkema-Paassen, J; Jansen, K; Gramsbergen, A; Meek, MF

    2004-01-01

    Disruption of peripheral nerves due to trauma is a frequently Occurring clinical problem. Gaps in the nerve are bridged by guiding the regenerating nerves along autologous grafts or artificial guides. This review gives an overview oil the different methods of nerve repair techniques. Conventional su

  10. Biotribological properties of UHMWPE grafted with AA under lubrication as artificial joint.

    Science.gov (United States)

    Deng, Yaling; Xiong, Dangsheng; Wang, Kun

    2013-09-01

    Osteolysis caused by wear particles from polyethylene in the artificial hip joints is a serious issue. In order to endow the low friction and wear of the bearing surface of ultra-high molecular weight polyethylene (UHMWPE) artificial joint for a longer term, hydrophilic acrylic acid (AA) was grafted on UHMWPE powders with the method of ultraviolet irradiation and then the modified powders were hot pressed. The tribological properties of modified UHMWPE sliding against CoCrMo metallic plate on reciprocating tribometer under calf serum, saline and distilled water lubrication during a long-term friction were investigated. The measurement of Fourier-transform infrared spectroscopy indicates that AA is successfully grafted on the surface of UHMWPE powders by photo-induced graft polymerization. Contact angles of UHMWPE are decreased from 83° to 35° by grafting and the surface wettability is effectively improved. The tensile strength of modified sample decreases. The friction coefficient and wear rate of UHMWPE-g-PAA under calf serum, saline and distilled water lubrication are lower than that of untreated UHMWPE. With the increase of grafting ratio, the wear rate of UHMWPE-g-PAA decreases firstly and then increases. The modified UHMWPE with grafting ratio of 3.5 % has the lowest wear rate, which is just quarter of the untreated UHMWPE. The hydrated PAA polymer brushes enclosed in the UHMWPE bulk material provide continuous lubrication during long term sliding.

  11. Repair of a long nerve defect with a tissue - engineered bioartificial nerve graft: a preliminary report%组织工程化人工神经修复长段神经缺损实验的初步报告

    Institute of Scientific and Technical Information of China (English)

    沈尊理; BergerAlfred; 等

    2001-01-01

    Objective To evaluate the effectiveness of a tissue - engineered artificial nerve on bridging sciatic nerve defect 2.5 cm in length in rats. Methods 90 female Lewis 1W rats aged 2 months were randomly divided into three groups, with 30 in each. Three types of materials were used as graft: group A, collagen nerve tubes with an intrinsic framework seeded with syngeneic Schwann cells, which were referred as tissue - engineered artificial nerves; group B, collagen nerve tubes filled with an intrinsic framework without Schwann cells; and group C, nerve autografts. Six months later, a series of examinations were performed as follows: electrophysiological testing, hisotological staining of nerves and muscles, S - 100 and neurofilament immunostaining as well as axon counts.Results Until now, the assessment has been finished in 21 rats (7 rats in each group). A significant compound muscle action potential (CMAP) was evoked in anterior tibial muscle in group A and C. Regenerated axons were observed in the whole length of nerve grafts, with mild atrophy of their innervating muscles. On the contrary, nothing or only a tiny CMAP was recorded in group B. The distal parts of nerve grafts were filled with fibrotic tissue, while regenerated axons were rarely seen. There was a significant atrophy of the related muscles. Conclusions Our preliminary results demonstrated that the tissue - engineered artificial nerve could effectively repair a long nerve defect in rats.%目的研究组织工程化人工神经修复大鼠2.5 cm长坐骨神经缺损的效果。方法 90只2个月月龄的Lewis 1W雌性大鼠,按手术先后顺序随机分成3个神经移植组, 每组30只。A组:用种植同源雪旺细胞并具有内部支架结构的胶原神经管桥接,即组织工程化人工神经组。B组:用无雪旺细胞但具有内部支架结构的胶原神经管桥接, 即对照组。C组:自体神经移植组。术后6个月,进行神经电生理监测,神经

  12. Reanimation of reversible facial paralysis by the double innervation technique using an intraneural-dissected sural nerve graft.

    Science.gov (United States)

    Tomita, Koichi; Hosokawa, Ko; Yano, Kenji

    2010-06-01

    In treating reversible facial paralysis, cross-facial nerve grafting offers voluntary and emotional reanimation. In contrast, rapid re-innervation and strong neural stimulation can be obtained with hypoglossal-facial nerve crossover. In this article, we describe the method of a combination of these techniques as a one-stage procedure. A 39-year-old man presented with facial paralysis due to nerve avulsion within the stylomastoid foramen. The sural nerve was harvested and two branches were created at its distal end by intraneural dissection. One branch was anastomosed to the contralateral facial nerve, and the other branch was used for hypoglossal-facial nerve crossover, followed by connecting the proximal stump of the graft to the trunk of the paralysed facial nerve in an end-to-end fashion. At 9 months postoperatively, almost complete facial symmetry and co-ordinated movements of the mimetic muscles were obtained with no obvious tongue atrophy. Since our method can efficiently gather neural inputs from the contralateral facial nerve and the ipsilateral hypoglossal nerve, it may become a good alternative for reanimation of reversible facial paralysis when the ipsilateral facial nerve is not available.

  13. 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.

  14. Survival and migration of Schwann cells after the vascularized peripheral nerve grafted into spinal cord in rats

    Institute of Scientific and Technical Information of China (English)

    GUO Qing-shan; WANG Ai-min; WANG Xiao-jun; SUN Hong-zhen; DU Quan-yin

    2005-01-01

    Objective:To study the survival and ability of inducing axonal regeneration of the Schwann cells after the peripheral nerve being grafted into spinal cord. Methods:A total of 30 adult female Wistar rats were randomly divided into the VN (vascularized peripheral nerve) and PN (peripheral nerve) groups. A 5-mm spinal cord defect of the left posterior column was made at the T1-3 vertebral level. The defect was grafted with the vascularized or isolated peripheral nerve respectively. The survival and proliferation of the Schwann cells were assessed by histological and morphometric analysis 8 weeks after the operation. Results:In the VN group, the peripheral nerve grew into the cord with lots of Schwann cells survived and proliferated, and had more NF and S-100 positive fibers than in the PN group. Conclusion:The vascularized peripheral nerve enhances the survival and proliferation of the Schwann cells and prompts the regeneration of injured axon of the central nerve system to certain degree.

  15. Acellular nerve scaffold loading bone marrow mesenchymal stem cells to prepare artificial nerve for sciatic nerve defects%无细胞神经支架复合骨髓间充质干细胞构建组织工程人工神经修复坐骨神经缺损

    Institute of Scientific and Technical Information of China (English)

    张彩顺; 吕刚

    2011-01-01

    背景:作者已经成功制备了无细胞神经移植物,并且复合骨髓间充质干细胞构建组织工程人工神经桥接大鼠坐骨神经缺损.目的:无细胞神经移植物复合骨髓间充质干细胞构建组织工程人工神经修复大鼠坐骨神经缺损后运动功能的恢复.方法:成年雄性SD大鼠构建大鼠坐骨神经15 mm缺损模型,分别应用组织工程人工神经、组织工程神经支架或自行神经桥接坐骨神经缺损.桥接后20周再生神经电生理学测定,手术侧胫骨前肌湿质量、腓肠肌组织学及透视电镜分析.结果与结论:桥接20周后,组织工程人工神经与自体神经移植组胫骨前肌湿质量比较,差异无显著性意义(P > 0.05),神经干传导速度为(30.56±2.15)m/s.结果提示,无细胞神经移植物复合骨髓间充质干细胞构建的组织工程人工神经桥接大鼠坐骨神经缺损后,可以促进再生神经运动功能的恢复.%BACKGROUND: The authors have successfully prepared an acellular nerve graft to be combined with bone marrow mesenchymal stem cells in artificial nerve bridge of rat sciatic nerve defects.OBJECTIVE: To investigate the motor function of rats with sciatic nerve defects following repairing using acellular nerve graft combined with bone marrow mesenchymal stem cells.METHODS: Adult SD rats were used to prepare rat models of 15-mm sciatic nerve defects. Tissue-engineered nerve, tissue-engineered nerve scaffold, and autogenous nerve were separately applied to bridge sciatic nerve defects. After 20 weeks, electrophysiological determination of regenerated nerves was conducted, wet weight of the anterior tibial muscle was determined,and histological and transmission electron microscopy analyses of the gastrocnemius was done.RESULTS AND CONCLUSION: Twenty weeks after nerve grafting, no difference in the wet weight of the anterior tibial muscle was shown to be significant between tissue-engineered nerve and autogenous nerve grafts (P > 0

  16. 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.

  17. Surface modification of silicone rubber membrane by plasma induced graft copolymerization as artificial cornea.

    Science.gov (United States)

    Hsiue, G H; Lee, S D; Chang, P C

    1996-11-01

    In this study a highly biocompatible polymer membrane was prepared by surface modification. An artificial cornea was also developed for clinical applications. Silicone rubber (SR) membrane was grafted with hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA) and acrylic acid by plasma induced grafted polymerization. Surface properties of the SR were characterized using secondary ions mass spectra, Fourier transform infrared/attenuated total reflection, and element spectra for chemical analysis. The corneal epithelial (CE) cell was cultured in vitro, and penetrating keratoplasty of albino rabbit cornea (in vivo) was performed to evaluate biological properties of modified SR membranes. The ability of the CE cell to attach onto various SR membranes was observed by inverted microscopy. The proliferation of CE cell was conducted in approximately 96 h. Experimental results indicated that the attachment and growth of CE onto SR-g-pHEMA (75 micrograms/ cm2) is enhanced. The morphologies of an attached CE cell are similar to those of a primary CE cell. In the in vivo study, the depth of anterior chamber was maintained 2 weeks after penetrating keratoplasty was performed with a SR grafted with pHEMA (210 micrograms/cm2). This phenomenon displayed a high biocompatibility of modified SR membrane with the CE cell. Furthermore, results in this study provide a valuable reference for application of the modified SR for an artificial cornea.

  18. Repairment of sciatic nerve defect by Schwann cell of adult rat combined with acellular nerve grafts%成年大鼠许旺细胞复合去细胞神经支架修复坐骨神经缺损

    Institute of Scientific and Technical Information of China (English)

    周丽娜; 崔晓军; 苏开鑫; 王晓红; 蔡雪彦; 郭金华; 纳青青

    2015-01-01

    目的:探讨成年许旺细胞(SC)复合去细胞神经支架构建的组织工程化人工神经移植治疗外周神经损伤的效果。方法从 Wallerian 变性1周的成年 SD 大鼠远侧端神经中分离培养得到SC,复合去细胞神经支架构建组织工程化人工神经。移植分为 SC +去细胞 SD 大鼠神经支架组(SC治疗组)和空细胞 SD 大鼠神经支架组(阴性对照组),每组各5只。比较两组大鼠术后2、4、8周损伤侧坐骨神经功能指数(SFI),术后 8周损伤侧坐骨神经传导功能和小腿三头肌湿重恢复率等修复效果的指标。结果SC 治疗组术后2、4、8周损伤侧 SFI,术后 8周损伤侧坐骨神经传导功能和小腿三头肌湿重恢复率均优于或高于阴性对照组(均为 P <0.05)。结论采用成年 SC 复合去细胞神经支架的人工神经移植治疗外周神经缺损,可有效促进损伤神经的功能恢复。%Objective To investigate clinical efficacy of tissue-engineered artificial nerve grafts constructed by acellular nerve grafts combined with adult rat Schwann cell (SC)in the treatment of peripheral nerve injury.Methods SCs were isolated and cultured from the distal nerves of adult Sprague Dawley (SD) rats with 1-week Wallerian degeneration and then combined with acellular nerve grafts to construct tissue-engineered artificial nerve.All rats were divided into acellular nerve graft containing SCs (SC group)and nerve graft containing no cells groups (control group),five animals in each group.At 2-,4-and 8-week after surgery,sciatic function index (SFI)of the affected side was compared between two groups.At postoperative 8 weeks,nerve conduction of sciatic nerve of the injured side,recovery rate of triceps surae wet weight and other relevant parameters were equally compared between two groups.Results In the SC group,SFI of the affected side at 2-,4-and 8-week after surgery,nerve conduction of sciatic nerve at the injured side

  19. 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.

  20. Heterobifunctional membranes by plasma induced graft polymerization as an artificial organ for penetration keratoprosthesis.

    Science.gov (United States)

    Chang, P C; Lee, S D; Hsiue, G H

    1998-03-05

    Highly biocompatible polymer membrane was developed for an artificial cornea in this surface modification study. Heterobifunctional silicone rubber membranes (hetero-SR) were prepared by grafting different functional polymers on each side of a silicone rubber membrane (SR). A novel type of bifunctional membrane was developed with the upper-side favoring cell attachment and growth, and the lower-side suppressing cell adhesion. The preparation of heterobifunctional membranes, characterization of polymer membrane surface properties such as ATR-FTIR and ESCA and contact angle, and biological analysis (in vitro and in vivo studies) were investigated in this work. Based on the biological analysis, the heterobifunctional membrane displays promising potential for use as an artificial cornea.

  1. 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.

  2. Engineering interaction between bone marrow derived endothelial cells and electrospun surfaces for artificial vascular graft applications.

    Science.gov (United States)

    Ahmed, Furqan; Dutta, Naba K; Zannettino, Andrew; Vandyke, Kate; Choudhury, Namita Roy

    2014-04-14

    The aim of this investigation was to understand and engineer the interactions between endothelial cells and the electrospun (ES) polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) nanofiber surfaces and evaluate their potential for endothelialization. Elastomeric PVDF-HFP samples were electrospun to evaluate their potential use as small diameter artificial vascular graft scaffold (SDAVG) and compared with solvent cast (SC) PVDF-HFP films. We examined the consequences of fibrinogen adsorption onto the ES and SC samples for endothelialisation. Bone marrow derived endothelial cells (BMEC) of human origin were incubated with the test and control samples and their attachment, proliferation, and viability were examined. The nature of interaction of fibrinogen with SC and ES samples was investigated in detail using ELISA, XPS, and FTIR techniques. The pristine SC and ES PVDF-HFP samples displayed hydrophobic and ultrahydrophobic behavior and accordingly, exhibited minimal BMEC growth. Fibrinogen adsorbed SC samples did not significantly enhance endothelial cell binding or proliferation. In contrast, the fibrinogen adsorbed electrospun surfaces showed a clear ability to modulate endothelial cell behavior. This system also represents an ideal model system that enables us to understand the natural interaction between cells and their extracellular environment. The research reported shows potential of ES surfaces for artificial vascular graft applications.

  3. 无细胞神经移植物复合骨髓间充质干细胞修复大鼠坐骨神经缺损%Repairing rat sciatic nerve defects with the compound of acellular nerve graft and bone marrow mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    张彩顺; 吕刚; 张基仁; 肖强

    2009-01-01

    BACKGROUND: Previous studies have successfully prepared the natural and biologically degraded acellular nerve graft and have proved the effect of promoting neural regeneration.OBJECTIVE: To construct tissue engineered artificial nerve with acellular nerve graft and bone marrow mesenchymal stem cells, and to observe the effect of promoting motor functional recovery and repairing rat sciatic nerve defects. DESIGN, TIME AND SETTING: Randomized control animal experiment was performed in the Medical TIssue Engineering Laboratory of the First Affiliated Hospital of Liaoning Medical University between June 2008 and February 2009. MATERIALS: Wistar adult healthy male rats weighing 180-200 g were used to prepare acellular nerve graft, while Wistar adult healthy male rats weighing 100-120 g were used to prepare bone marrow mesenchymal stem cells. Tissue engineered artificial nerve was produced with acellular nerve graft co-cultured with bone marrow mesenchymal stem cells. METHODS: Sixty Wistar adult healthy male rats weighing 180-200 g were induced sciatic nerve defect models, 15 mm long. SD rats were divided into three groups at random with 20 animals in each group. ①Experiment group: Rat sciatic nerve defects were bridged with tissue engineered artificial nerve. ②Blank control group: Rat sciatic nerve defects were bridged with tissue engineered nerve scaffold. ③Autologous nerve control group: Rat sciatic nerve defects were bridged with autologous nerve graft. MAIN OUTCOME MEASURES: At 12 weeks postoperation, the recovery of motor function was evaluated with gross observation, electrophysiology, histological observation and triceps surae wet weight.RESULTS: ①At 12 weeks postoperation, the toes at the operation side could separate and supported to the ground in the experiment group; there was no significant difference in the regenerated nerve conduction velocity between experimental group and autologous nerve graft group. ②At 12 weeks postoperation, histochemical

  4. Design and characterization of artificial extracellular matrix proteins for use as small-diameter vascular grafts

    Science.gov (United States)

    Heilshorn, Sarah

    Synthetic small-diameter vascular grafts often fail within three years of implantation. The underlying causes of graft failure are thought to be (i) a mismatch in the mechanical properties between the graft and host material and (ii) an inability of the graft to support the adhesion of endothelial cells. To address these two issues, artificial extracellular matrix (aECM) proteins contain elastin-like regions to provide physical integrity and cell-binding domains derived from fibronectin to promote endothelial cell attachment. Using recombinant protein technology, a family of artificial proteins was created with differing ratios of elastin-like regions to cell-binding domains, with variable placement of amino acid crosslinking residues, and with differing identity of cell-binding domain. Human umbilical vein endothelial cells (HUVEC) adhere in a sequence-specific manner to aECM proteins, secrete basal levels of key fibrinolytic regulators, and are capable of resisting a physiologically relevant detachment force. HUVEC spread more quickly and adhere more firmly to aECM proteins that contain the RGD versus the CS5 cell-binding domain. Decreasing the density of RGD cell-binding domains results in decreased HUVEC adhesion. Furthermore, amino acid selection even at sites up to 16 residues away from the cell-binding domain impacts HUVEC spreading and adhesion. HUVEC also adhere more strongly to stiffer aECM films. Therefore, the identity, density, and context of the cell-binding domain as well as the elastic modulus of the substrate are all important variables in influencing cell-substrate interactions. Proper amino acid sequence choice also influences the susceptibility of aECM proteins to elastase proteolysis; modifying 3% of the amino acid side chains results in a 7-fold reduction in degradation rate. An alternative strategy to decrease degradation involves incorporation of the noncanonical amino acid, 5,5,5-trifluoroisoleucine, into the favored proteolytic cut site

  5. Comparison of hemihypoglossal-facial nerve transposition with a cross-facial nerve graft and muscle transplant for the rehabilitation of facial paralysis using the facial clima method.

    Science.gov (United States)

    Hontanilla, Bernardo; Vila, Antonio

    2012-02-01

    To compare quantitatively the results obtained after hemihypoglossal nerve transposition and microvascular gracilis transfer associated with a cross facial nerve graft (CFNG) for reanimation of a paralysed face, 66 patients underwent hemihypoglossal transposition (n = 25) or microvascular gracilis transfer and CFNG (n = 41). The commissural displacement (CD) and commissural contraction velocity (CCV) in the two groups were compared using the system known as Facial clima. There was no inter-group variability between the groups (p > 0.10) in either variable. However, intra-group variability was detected between the affected and healthy side in the transposition group (p = 0.036 and p = 0.017, respectively). The transfer group had greater symmetry in displacement of the commissure (CD) and commissural contraction velocity (CCV) than the transposition group and patients were more satisfied. However, the transposition group had correct symmetry at rest but more asymmetry of CCV and CD when smiling.

  6. 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

    2015-12-14

    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.

  7. One-stage, simultaneous skin grafting with artificial dermis and basic fibroblast growth factor successfully improves elasticity with maturation of scar formation.

    Science.gov (United States)

    Hamuy, Rodrigo; Kinoshita, Naoshi; Yoshimoto, Hiroshi; Hayashida, Kenji; Houbara, Seiji; Nakashima, Masahiro; Suzuki, Keiji; Mitsutake, Norisato; Mussazhanova, Zhanna; Kashiyama, Kazuya; Hirano, Akiyoshi; Akita, Sadanori

    2013-01-01

    The efficacy of one-stage artificial dermis and skin grafting was tested in a nude rat model. Reconstruction with artificial dermis is usually a two-stage procedure with 2- to 3-week intermission. If one-stage use of artificial dermis and split-thickness skin grafting are effective, the overall burden on patients and the medical cost will markedly decrease. The graft take rate, contraction rate, tissue elasticity, histology, morphometric analysis of the dermal thickness, fibroblast counting, immunohistochemistry of α-smooth muscle actin, matrix metalloproteinase-2, CD31, and F4/80, as well as gelatin zymography, real-time reverse transcriptase polymerase chain reaction for matrix metalloproteinase-2, and electron microscopy, were investigated from day 3 to 3 months postoperatively. The graft take rate was good overall in one-stage artificial dermis and skin grafting groups up to 3 weeks, and the contraction rate was greater in the two-staged artificial dermis and skin grafting group than in the skin grafting alone or one stage of artificial dermis and skin grafting groups. Split-thickness skin grafting with artificial dermis and basic fibroblast growth factor at a concentration of 1 μg/cm(2) showed significantly greater elasticity by Cutometer, and the dermal thickness was significantly thinner, fibroblast counting was significantly greater, and the α-smooth muscle actin expression level was more notable with a more mature blood supply in the dermis and more organized dermal fibrils by electron microscopy at 3 weeks. Thus, one-stage artificial dermis and split-thickness skin grafting with basic fibroblast growth factor show a high graft take rate and better tissue elasticity determined by Cutometer analysis, maturity of the dermis, and increased fibroblast number and blood supply compared to a standard two-stage reconstruction.

  8. Effect of FGF-2 and sciatic nerve grafting on ChAT expression in dorsal root ganglia neurons of spinal cord transected rats.

    Science.gov (United States)

    Guzen, Fausto Pierdoná; de Araújo, Dayane Pessoa; Lucena, Eudes Euler de Souza; de Morais, Hécio Henrique Araújo; Cavalcanti, José Rodolfo Lopes de Paiva; do Nascimento, Expedito Silva; Costa, Miriam Stela Maris de Oliveira; Cavalcante, Jeferson Sousa

    2016-03-11

    Neurotrophic factors and peripheral nerves are known to be good substrates for bridging CNS trauma. The involvement of fibroblast growth factor-2 (FGF-2) activation in the dorsal root ganglion (DRG) was examined following spinal cord injury in the rat. We evaluated whether FGF-2 increases the ability of a sciatic nerve graft to enhance neuronal plasticity, in a gap promoted by complete transection of the spinal cord. The rats were subjected to a 4mm-long gap at low thoracic level and were repaired with saline (Saline or control group, n=10), or fragment of the sciatic nerve (Nerve group, n=10), or fragment of the sciatic nerve to which FGF-2 (Nerve+FGF-2 group, n=10) had been added immediately after lesion. The effects of the FGF-2 and fragment of the sciatic nerve grafts on neuronal plasticity were investigated using choline acetyl transferase (ChAT)-immunoreactivity of neurons in the dorsal root ganglion after 8 weeks. Preservation of the area and diameter of neuronal cell bodies in dorsal root ganglion (DRG) was seen in animals treated with the sciatic nerve, an effect enhanced by the addition of FGF-2. Thus, the addition of exogenous FGF-2 to a sciatic nerve fragment grafted in a gap of the rat spinal cord submitted to complete transection was able to improve neuroprotection in the DRG. The results emphasized that the manipulation of the microenvironment in the wound might amplify the regenerative capacity of peripheral neurons.

  9. Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man.

    Science.gov (United States)

    Kato, Kenji; Sasada, Syusaku; Nishimura, Yukio

    2016-02-01

    Controlling a neuroprosthesis requires learning a novel input-output transformation; however, how subjects incorporate this into limb control remains obscure. To elucidate the underling mechanisms, we investigated the motor adaptation process to a novel artificial recurrent connection (ARC) from a muscle to a peripheral nerve in healthy humans. In this paradigm, the ulnar nerve was electrically stimulated in proportion to the activation of the flexor carpi ulnaris (FCU), which is ulnar-innervated and monosynaptically innervated from Ia afferents of the FCU, defined as the "homonymous muscle," or the palmaris longus (PL), which is not innervated by the ulnar nerve and produces similar movement to the FCU, defined as the "synergist muscle." The ARC boosted the activity of the homonymous muscle and wrist joint movement during a visually guided reaching task. Participants could control muscle activity to utilize the ARC for the volitional control of wrist joint movement and then readapt to the absence of the ARC to either input muscle. Participants reduced homonymous muscle recruitment with practice, regardless of the input muscle. However, the adaptation process in the synergist muscle was dependent on the input muscle. The activity of the synergist muscle decreased when the input was the homonymous muscle, whereas it increased when it was the synergist muscle. This reorganization of the neuromotor map, which was maintained as an aftereffect of the ARC, was observed only when the input was the synergist muscle. These findings demonstrate that the ARC induced reorganization of neuromotor map in a targeted and sustainable manner.

  10. 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.

  11. 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.

  12. In vivo integration of poly(ε-caprolactone)/gelatin nanofibrous nerve guide seeded with teeth derived stem cells for peripheral nerve regeneration.

    Science.gov (United States)

    Beigi, Mohammad-Hossein; Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Karbalaie, Khadijeh; Azadeh, Hamid; Ramakrishna, Seeram; Baharvand, Hossein; Nasr-Esfahani, Mohammad-Hossein

    2014-12-01

    Artificial nanofiber nerve guides have gained huge interest in bridging nerve gaps and associated peripheral nerve regeneration due to its high surface area, flexibility and porous structure. In this study, electrospun poly (ε-caprolactone)/gelatin (PCL/Gel) nanofibrous mats were fabricated, rolled around a copper wire and fixed by medical grade adhesive to obtain a tubular shaped bio-graft, to bridge 10 mm sciatic nerve gap in in vivo rat models. Stem cells from human exfoliated deciduous tooth (SHED) were transplanted to the site of nerve injury through the nanofibrous nerve guides. In vivo experiments were performed in animal models after creating a sciatic nerve gap, such that the nerve gap was grafted using (i) nanofiber nerve guide (ii) nanofiber nerve guide seeded with SHED (iii) suturing, while an untreated nerve gap remained as the negative control. In vitro cell culture study was carried out for primary investigation of SHED-nanofiber interaction and its viability within the nerve guides after 2 and 16 weeks of implantation time. Walking track analysis, plantar test, electrophysiology and immunohistochemistry were performed to evaluate functional recovery during nerve regeneration. Vascularization was also investigated by hematoxilin/eosine (H&E) staining. Overall results showed that the SHED seeded on nanofibrous nerve guide could survive and promote axonal regeneration in rat sciatic nerves, whereby the biocompatible PCL/Gel nerve guide with cells can support axonal regeneration and could be a promising tissue engineered graft for peripheral nerve regeneration.

  13. Artificial cornea: surface modification of silicone rubber membrane by graft polymerization of pHEMA via glow discharge.

    Science.gov (United States)

    Lee, S D; Hsiue, G H; Kao, C Y; Chang, P C

    1996-03-01

    A method for producing various surfaces of silicone rubber membrane (SR) was developed in this study by grafting various amounts of poly(2-hydroxy ethyl methacrylate) (pHEMA) onto SR by plasma-induced grafted polymerization (PIP) as a homobifunctional membrane. The elemental composition and different carbon bindings on the surface of SR were examined by electron spectroscopy for chemical analysis with the amount of O1s/C1s being approximately 0.7 at 1 min, 60 W, 200 mTorr of Ar-plasma treatment. The peroxide group introduced on SR was measured via 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the amount of 6.85 x 10(-8) mol cm-2 reached optimum value at 1 min of Ar-plasma treatment. After Ar-plasma treated SR, the peroxide group (33D peak) was introduced on the surface of SR by negative spectra of secondary ion mass spectroscopy analysis, whereas ester groups (72D peak) were observed for pHEMA-grafted SR. For the in vitro test, the influence of various surfaces of SR on attachment and growth of rabbit corneal epithelial cells (CEC) was studied by cell culture assay. These results indicated that 56-150 micrograms cm-2 of pHEMA grafted onto SR were suitable values for attachment and growth of CEC. On the contrary, the large grafted amounts (500-1650 micrograms cm-2) of pHEMA on SR were insufficient for attachment and growth of CEC. For the in vivo test, the migration of CEC from host cornea to implant was investigated by slit lamp microscopy. The experimental results indicated that SRs grafted with pHEMA were completely covered with CEC 3 weeks after implantation of the membranes into the host cornea. These results provide a valuable reference for developing an artificial cornea.

  14. A Cell Line Producing Recombinant Nerve Growth Factor Evokes Growth Responses in Intrinsic and Grafted Central Cholinergic Neurons

    Science.gov (United States)

    Ernfors, Patrik; Ebendal, Ted; Olson, Lars; Mouton, Peter; Stromberg, Ingrid; Persson, Hakan

    1989-06-01

    The rat β nerve growth factor (NGF) gene was inserted into a mammalian expression vector and cotransfected with a plasmid conferring resistance to neomycin into mouse 3T3 fibroblasts. From this transfection a stable cell line was selected that contains several hundred copies of the rat NGF gene and produces excess levels of recombinant NGF. Such genetically modified cells were implanted into the rat brain as a probe for in vivo effects of NGF on central nervous system neurons. In a model of the cortical cholinergic deficits in Alzheimer disease, we demonstrate a marked increase in the survival of, and fiber outgrowth from, grafts of fetal basal forebrain cholinergic neurons, as well as stimulation of fiber formation by intact adult intrinsic cholinergic circuits in the cerebral cortex. Adult cholinergic interneurons in intact striatum also sprout vigorously toward implanted fibroblasts. Our results suggest that this model has implications for future treatment of neurodegenerative diseases.

  15. 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

  16. P3-7: On Prototyping a Visual Prosthesis System with Artificial Retina and Optic Nerve Based on Arrayed Microfibers

    Directory of Open Access Journals (Sweden)

    Jian Hong Chen

    2012-10-01

    Full Text Available The traditional visual prosthesis system combines both a camera and a microelectrode array implanted on the visual neural network including retina, optic nerve, and visual cortex. Here, we introduce a new visual prosthesis system in which an artificial retina and optic nerve are demonstrated. The prototype of optic nerve for image transmission is comprised of arrayed PMMA microfibers with both ends connected with two planes, one functioned as retina for light reception and another attached to visual cortex. The microfibers are drawn from the thin film prepared by PMMA/chlorobenzene solution. Each micro fiber serves as an optical waveguide for the delivery of a single image pixel. It is demonstrated that with proper imaging optics, arrayed micro fibers could be lit as discrete light spots in accordance with the input image. Each micro fiber is expected to function as a stimulation unit for optical neural modulation in a visual prosthesis system.

  17. Sensing and stimulation of the vagus nerve for artificial cardiac control

    NARCIS (Netherlands)

    Ordelman, Simone Cornelia Maria Anna

    2012-01-01

    This thesis focuses on sensing cardiovascular signals from the vagus nerve and electrically stimulating the vagus nerve for cardiovascular effects. Sensing cardiovascular signals was attempted on both spontaneous and evoked neural activity. A cardiac-modulated vagus nerve activity pattern was found

  18. The effect of polystyrene sodium sulfonate grafting on polyethylene terephthalate artificial ligaments on in vitro mineralisation and in vivo bone tissue integration

    Science.gov (United States)

    Vaquette, Cédryck; Viateau, Véronique; Guérard, Sandra; Anagnostou, Fani; Manassero, Mathieu; Castner, David G.; Migonney, Véronique

    2013-01-01

    This study investigates the impact of polystyrene sodium sulfonate (PolyNaSS) grafting onto the osseointegration of a polyethylene terephthalate artificial ligament (Ligament Advanced Reinforcement System, LARS™) used for Anterior Cruciate Ligament (ACL). The performance of grafted and non-grafted ligaments was assessed in vitro by culturing human osteoblasts under osteogenic induction and this demonstrated that the surface modification was capable of up-regulating the secretion of ALP and induced higher level of mineralisation as measured 6 weeks post-seeding by Micro-Computed Tomography. Grafted and non-grafted LARS™ were subsequently implanted in an ovine model for ACL reconstruction and the ligament-to-bone interface was evaluated by histology and biomechanical testing 3 and 12 months post-implantation. The grafted ligaments exhibited more frequent direct ligament-to-bone contact and bone formation in the core of the ligament at the later time point than the nongrafted specimens, the grafting also significantly reduced the fibrous encapsulation of the ligament 12 months post-implantation. However, this improved osseo-integration was not translated into a significant increase in the biomechanical pull-out loads. These results provide evidences that PolyNaSS grafting improved the osseo-integration of the artificial ligament within the bone tunnels. This might positively influence the outcome of the surgical reconstructions, as higher ligament stability is believed to limit micro-movement and therefore permits earlier and enhanced healing. PMID:23790438

  19. Nerve regeneration and elastin formation within poly(glycerol sebacate)-based synthetic arterial grafts one-year post-implantation in a rat model

    Science.gov (United States)

    Allen, Robert A.; Wu, Wei; Yao, Mingyi; Dutta, Debaditya; Duan, Xinjie; Bachman, Timothy N.; Champion, Hunter C.; Stolz, Donna B.; Robertson, Anne M.; Kim, Kang; Isenberg, Jeffrey S.; Wang, Yadong

    2013-01-01

    The objective of this study was to evaluate the long term performance of cell-free vascular grafts made from a fast-degrading elastic polymer. We fabricated small arterial grafts from microporous tubes of poly(glycerol sebacate) (PGS) reinforced with polycaprolactone (PCL) nanofibers on the outer surface. Grafts were interpositioned in rat abdominal aortas and characterized at 1 year post-implant. Grafts remodeled into “neoarteries” (regenerated arteries) with similar gross appearance to native rat aortas. Neoarteries mimic arterial tissue architecture with a confluent endothelium and media and adventita-like layers. Patent vessels (80%) showed no significant stenosis, dilation, or calcification. Neoarteries contain nerves and have the same amount of mature elastin as native arteries. Despite some differences in matrix organization, regenerated arteries had similar dynamic mechanical compliance to native arteries in vivo. Neoarteries responded to vasomotor agents, albeit with different magnitude than native aortas. These data suggest that an elastic vascular graft that resorbs quickly has potential to improve the performance of vascular grafts used in small arteries. This design may also promote constructive remodeling in other soft tissues. PMID:24119457

  20. Effect of a Nerve Graft Substitute Single-walled Carbon Nanotubes on Rat Pheochromocytoma Cells

    Institute of Scientific and Technical Information of China (English)

    WU Qian; ZHANG Juan; HU Zheqin

    2015-01-01

    Carbon nanotubes (CNTs) were extensively explored for their beneficial use in nervous system tissue engineering. However, an important concern regarding the use of CNTs is their toxicity during the interaction between cells and the nano particles. The rat pheochromocytoma cell line (PC12) was co-cultured with three types of single-walled carbon nanotubes (SWNTs), purified raw SWNTs (C), hydroxyl purified SWNTs (C-OH) and carboxyl purified SWNTs (C-COOH) at 25 µg/mL and 100 µg/ml. The experimental results revealed that SWNTs at the concentration below 100 µg/mL did not affect the cell viability. Notably, powerful antioxidant system in nerous system tissue is able to counteract with the toxicity of CNTs, which is characterized by the prominently enhanced expression of main antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST)). Therefore, we believe that CNTs can be good candidates for the fabrication of biomedical scaffolds for the nerve tissue repair.

  1. Hairy polyelectrolyte brushes-grafted thermosensitive microgels as artificial synovial fluid for simultaneous biomimetic lubrication and arthritis treatment.

    Science.gov (United States)

    Liu, Guoqiang; Liu, Zhilu; Li, Na; Wang, Xiaolong; Zhou, Feng; Liu, Weimin

    2014-11-26

    We report the fabrication of poly(3-sulfopropyl methacrylate potassium salt) (PSPMK) brushes grafted poly(N-isopropylacrylamide) (PNIPAAm) microgels and their potential as artificial synovial fluid for biomimetic aqueous lubrication and arthritis treatment. The negatively charged PSPMK brushes and thermosensitive PNIPAAm microgels play water-based hydration lubrication and temperature-triggered drug release, respectively. Under soft friction pairs, an ultralow coefficient of friction was achieved, while the hairy thermosensitive microgels showed a desirable temperature-triggered drugs release performance. Such a soft charged hairy microgel offers great possibility for designing intelligent synovial fluid. What is more, the combination of lubrication and drug loading capabilities enables the large clinical potential of novel soft hairy nanoparticles as synthetic joint lubricant fluid in arthritis treatment.

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

    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.

  3. Specificity of reinnervation and motor recovery after interposition of an artificial barrier between transected and repaired nerves in adjacency--an experimental study in the rat.

    Science.gov (United States)

    Lutz, B S; Ma, S F; Chuang, D C; Lidman, D; Wei, F C

    2001-01-01

    Non-specific re-innervation of target organs caused by misdirected axonal growth at the repair site is regarded as one reason for a poor functional outcome after peripheral nerve transsection and repair. This study investigates the rate of aberrant re-innervation and its influence on motor recovery in the rat sciatic nerve using artificial sheets as barrier between tibial and peroneal nerves. The sciatic nerve was transsected and repaired as follows: epineural sutures (A x 6), fascicular repair of tibial and peroneal nerves respectively (B x 8), and the same as in group B, but separating both nerves using an Integra-sheet with silicone (C x 8), or Integra without silicone (D x 8). As control, solely the tibial nerve was transsected and repaired (E x 5). Final investigations after 4 months revealed that in group C, 50% of the Integra-silicone sheets were dislocated. No dislocation was found in group D. Muscle contraction force of the gastrocnemius muscle was significantly higher in group E as compared to all other groups. However although not significant, group D showed a consistently higher muscle contraction force than groups A, B, and C. Histology in groups A, B, and C with dislocated sheets demonstrated multiple axons growing from the tibial to the peroneal nerve and vice versa. In groups D and E, no such axonal growth was visible. These findings were confirmed by a significantly higher rate of specific reinnervation of the soleus muscle using sequential retrograde double labelling technique. Results of this study suggest that an artificial sheet such as Integra bears the potential of preventing aberrant re-innervation between repaired adjacent nerves resulting in improved motor recovery. Clinically, this technique may be of importance for brachial plexus, sciatic nerve, and facial nerve repair.

  4. 预血管化组织工程神经修复周围神经缺损的研究%Repairing peripheral nerve defect with prevascularized artificial nerve

    Institute of Scientific and Technical Information of China (English)

    蒋良福; 陈鸥; 虞庆; 褚庭纲; 丁健; 李志杰

    2014-01-01

    Objective To evaluate the effectiveness of prevascularized acellular nerve graft combined with autologous differentiated adipose-derived stem cells on repairing nerve defect in rats.Methods Adiposederived stem cells (ADSCs) were isolated from rat inguinal fat pad.Vascular endothelial growth factor (VEGF) encapsulated nanoparticles were injected into the chemically decellularized nerve graft which in turn was buried into the incision for fat harvesting.The rat was kept for 2 weeks to allow prevascularization of the acellular nerve graft.The ADSCs were cultured under neurogeneic conditions for 2 weeks to differentiate into Schwann cells.A 15 mm sciatic nerve gap in rats was repaired by VEGF nanoparticle prevascularized acellular nerve graft injected with differentiated ADSCs (Group A),by non-VEGF nanoparticle prevascularized acellular nerve injected with differentiated ADSCs (Group B),by acellular nerve injected with differentiated ADSCs (Group C),by autologous nerve graft (Group D),and by VEGF nanoparticle prevascularized acellular nerve graft (Group E).On postoperative day 7 grafts from Groups A,B and C were harvested.Microvessel density (MVD) and graft cell apoptosis were examined.After 12 weeks,nerve conduction study,triceps surae muscle wet weight,and neuromorphometry analysis were carried out to evaluate the extent of nerve regeneration.Results Seven days postoperatively,graft cell apoptosis was most prominent in group C.Apoptosis in group A was less severe than Group B.MVD was highest in group A,followed by group B and then group C.Evaluations at 12 weeks postoperatively showed significantly higher nerve conduction velocity,larger action potential amplitude,higher triceps surae muscle weight recovery rate and larger myelinated nerve fiber count in Group A than in Group B,Group C and Group E (P < 0.05).Conclusion There is a synergistic effect of acellular nerve and differentiated ADSCs in repairing nerve gap in rats.The prevascularized acellular nerve

  5. Extracellular matrix components in peripheral nerve regeneration.

    Science.gov (United States)

    Gonzalez-Perez, Francisco; Udina, Esther; Navarro, Xavier

    2013-01-01

    Injured axons of the peripheral nerve are able to regenerate and, eventually, reinnervate target organs. However, functional recovery is usually poor after severe nerve injuries. The switch of Schwann cells to a proliferative state, secretion of trophic factors, and the presence of extracellular matrix (ECM) molecules (such as collagen, laminin, or fibronectin) in the distal stump are key elements to create a permissive environment for axons to grow. In this review, we focus attention on the ECM components and their tropic role in axonal regeneration. These components can also be used as molecular cues to guide the axons through artificial nerve guides in attempts to better mimic the natural environment found in a degenerating nerve. Most used scaffolds tested are based on natural molecules that form the ECM, but use of synthetic polymers and functionalization of hydrogels are bringing new options. Progress in tissue engineering will eventually lead to the design of composite artificial nerve grafts that may replace the use of autologous nerve grafts to sustain regeneration over long gaps.

  6. Wear resistance of artificial hip joints with poly(2-methacryloyloxyethyl phosphorylcholine) grafted polyethylene: comparisons with the effect of polyethylene cross-linking and ceramic femoral heads.

    Science.gov (United States)

    Moro, Toru; Kawaguchi, Hiroshi; Ishihara, Kazuhiko; Kyomoto, Masayuki; Karita, Tatsuro; Ito, Hideya; Nakamura, Kozo; Takatori, Yoshio

    2009-06-01

    Aseptic loosening of artificial hip joints induced by wear particles from the polyethylene (PE) liner remains the ruinous problem limiting their longevity. We reported here that grafting with a polymer, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)) (PMPC), on the PE liner surface dramatically decreased the wear production under a hip joint simulator condition. We examined that the effect of properties of both PE by cross-linking and femoral head by changing the materials on wearing properties of PE. The PMPC grafting on the liners increased hydrophilicity and decreased friction torque, regardless of the cross-linking of the PE liner or the difference in the femoral head materials. During the hip joint simulator experiments (5 x 10(6) cycles of loading), cross-linking caused a decrease of wear amount and a reduction of the particle size, while the femoral head materials did not affect it. The PMPC grafting abrogated the wear production, confirmed by almost no wear of the liner surface, independently of the liner cross-linking or the femoral head material. We concluded that the PMPC grafting on the PE liner surpasses the liner cross-linking or the change of femoral head materials for extending longevity of artificial hip joints.

  7. Repair of skin defect with autologous head skin graft and artificial dermis graft in 10 children cases%人工真皮联合头部断层薄皮片修复小儿皮肤缺损

    Institute of Scientific and Technical Information of China (English)

    田彭; 周业平

    2012-01-01

    目的 研究并评价人工真皮联合头部薄皮片修复小儿皮肤缺损,为临床治疗提供依据.方法 2009年3月至2011年3月我院烧伤科治疗患儿10例,男8例,女2例,年龄5~12岁,平均(8±2.5)岁,其中3例热烧伤,4例外伤,3例为皮瓣转移供瓣区皮肤缺损.所有皮肤缺损均通过人工真皮移植联合头部薄断层皮片移植两次手术进行修复,观察人工真皮及头部薄断层皮片存活情况,供皮区愈合情况及愈合后外观.结果 所有人工真皮及头部薄皮片均存活,头部供皮区7~10d愈合.随访未发现明显皮片挛缩及瘢痕增生影响肢体功能.结论 人工真皮联合头部薄皮片可以修复小儿皮肤缺损,并达到较好效果,可以为将来手术保留较好的皮源.%Objective This study appraised the application of artificial dermis and autologus head skin graft in repairing skin defects in children.Methods 10 children underwent artificial dermis and autologus head skin transplantation at the Department of Burn and Plastic Surgery,Beijing Jishuitan Hospital from March 2009 to March 2011.The clinical data were collected.After debridement,artificial dermis graft was performed and followed by autologus split thickness skin transplantation,taken from head skin.The survival of artificial demis and autologus head skin graft was observed.Results Artificial dermis and autologus head skin both survived well,and the skin defect was repaired efficiently.No obvious scar occurred.Conclusions This study showed that prompt artificial dermis and autologous head skin graft could help repair skin defects and reserve the skin of limbs and abdomen as donor sites for future operation.

  8. 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.

  9. 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.

  10. Correction of surgically induced erectile dysfunction in the rat by repairing ablated cavernous nerve with neural stem cell grafts%神经干细胞移植重建勃起功能的研究

    Institute of Scientific and Technical Information of China (English)

    袁小旭; 邱剑光

    2010-01-01

    Objective To investigate the feasibility of restoring erectile function by repairing abla-ted cavernous nerve with neural stem cell grafts. Methods Forty-two male Sprague-Dawley rats (3-4 months old, weighing 300-400 g) were randomly divided into three groups: sham-operated controls (n = 14 ) subject to pelvic exploration without transection of the cavernous nerve; nerve ablation group (n = 14) having a 3 nun segment of cavernous nerve excised bilaterally; graft group (n = 14) having a 3 mm segment of cavernous nerve excised bilaterally, followed by immediate neural stem cell grafting. Two and 4 months postoperatively the rats of each group were electrostimulated to the cavernousal nerves to determine potency. Corpora cavernosa were harvested and nNOS-positive nerve fibers were examined by using immunohisto-chemistry. Results At the 2nd month postoperatively, electrical stimulation produced no erections in the nerve ablation or the graft group and 100 % erections in the sham-operated group. There was no significant difference in the nNOS-positive nerve fibers between the nerve ablation group and the graft group. At the 4th month postoperatively, 57. 14% of the grafted nerves produced erections upon electrical stimulation, significantly different from that in the nerve ablation group (7. 19% ). The nNOS-positive nerve fibers in the graft group (86. 0 ± 13.4) significantly differed from those in the nerve ablation group (26. 5±4. 3), and approximated the level of the sham-operated group (95.1 ± 7.7). Conclusion Neural stem cell graft-ing can be an effective method in restoring potency after injury.%目的 观察神经干细胞移植修复损伤的海绵体神经从而恢复勃起功能的可行性.方法 42只雄性SD大鼠(3~4个月龄和体质量300~400 g)随机分为假手术组、神经干细胞移植组和神经损伤组,每组14只.2、4个月后,海绵体神经电刺激检测大鼠阴茎勃起功能,免疫组织化学法检测海绵体内一氧化氮

  11. Analyze the Efficacy of 50 Cases of Free Nerve Graft Repair of Peripheral Nerve Injury%游离神经移植修复周围神经缺损50例疗效分析

    Institute of Scientific and Technical Information of China (English)

    王杰; 王浩; 黄飞; 黄荣华; 范亚生

    2015-01-01

    目的:探讨游离神经移植修复在周围神经损伤患者中的临床治疗效果。方法:对来笔者医院诊断、治疗的50例周围神经损伤患者相关资料进行分析,根据患者不同治疗方法将其分为两组,每组各25例,对照组采用单纯的神经游离移植,试验组实施带血管的神经游离移植,比较两组治疗效果。结果:试验组92.0%患者对修复方案给予肯定评价,高于对照组的76.0%;试验组92.0%对修复方案满意,高于对照组的72.0%;试验组ADL评分为(16.2±3.7)分,躯体功能评分为(59.6±7.5)分,心理功能评分为(65.8±9.2)分,社会功能评分为(57.2±6.5)分,均高于对照组,两组比较差异有统计学意义(P<0.05);试验组并发症发生率为8.0%,低于对照组的28.0%。结论:周围神经损伤发病率较高,临床上采用带血管的神经游离移植修复效果理想,值得推广使用。%Objective:To explore the free nerve graft repair clinical outcomes in patients with peripheral nerve injury.Method:The data of 50 patients with peripheral nerve injury was analyzed,according to the different methods of treatment,the patients were divided into two groups,25 cases in each group.The control group was treated by a simple nerve graft,the experimental group was implemented the free vascularized nerve transplant treatment,the effect of two groups were compared.Result:92.0% of patients in the experimental group affirmed rehabilitation program evaluation, higher than control group of 76.0%.92.0% for the experimental group rehabilitation program satisfaction was higher than the control group of 72.0%.The experimental group of ADL scores were (16.2±3.7)points,physical function scores were (59.6±7.5)points,psychological function score were (65.8±9.2)points,social function score were (57.2±6.5) points,higher than the control group,the difference was statistically significant(P<0.05).The experimental

  12. Cross-face nerve grafting for reanimation of incomplete facial paralysis: quantitative outcomes using the FACIAL CLIMA system and patient satisfaction.

    Science.gov (United States)

    Hontanilla, Bernardo; Marre, Diego; Cabello, Alvaro

    2014-01-01

    Although in most cases Bell palsy resolves spontaneously, approximately one-third of patients will present sequela including facial synkinesis and paresis. Currently, the techniques available for reanimation of these patients include hypoglossal nerve transposition, free muscle transfer, and cross-face nerve grafting (CFNG). Between December 2008 and March 2012, eight patients with incomplete unilateral facial paralysis were reanimated with two-stage CFNG. Gender, age at surgery, etiology of paralysis denervation time, donor and recipient nerves, presence of facial synkinesis, and follow-up were registered. Commissural excursion and velocity and patient satisfaction were evaluated with the FACIAL CLIMA and a questionnaire, respectively. Mean age at surgery was 33.8 ± 11.5 years; mean time of denervation was 96.6 ± 109.8 months. No complications requiring surgery were registered. Follow-up period ranged from 7 to 33 months with a mean of 19 ± 9.7 months. FACIAL CLIMA showed improvement of both commissural excursion and velocity greater than 75% in 4 patients, greater than 50% in 2 patients, and less than 50% in the remaining two patients. Qualitative evaluation revealed a high grade of satisfaction in six patients (75%). Two-stage CFNG is a reliable technique for reanimation of incomplete facial paralysis with a high grade of patient satisfaction.

  13. Monitoring of ultrasonography in artificial vascular graft for arteriovenous fistula%人工血管移植动静脉瘘术后超声检测价值

    Institute of Scientific and Technical Information of China (English)

    韩秀婕; 陈秀华; 任俊红

    2008-01-01

    Objective To evaluate the monitoring of ultrasonography in artificial vascular graft for arteriovenous fistula and its complications in patients with chronic renal failure. Methods Eighteen cases of artificial vascular graft arteriovenous fistula after four to six weeks were enrolled. The diameter, the peak velocity and blood flow were examined in arterial fistula. And the artificial vascular diameter, the peak velocity and blood flow of artificial vessels next to artery were all examined and analyzed. And the patients with symptoms in the upper extremity were tested by ultrasound. Results Intravascular blood showed good filling in fistula and artificial blood vessels in four to six weeks after artificial vascular graft for arteriovenous fistula by color doppler ultrasonography. The arterial fistula diameter, the peak velocity and blood flow were(3.61±0.68)mm and(298.56±93.42)cm/s and (583.62±216.77)ml/min. Artificial vascular diameter in (4.47±0.61)mm, the peak velocity and blood flow were (219.37±68.42)cm/s and (325.23±117.12) ml/min in the artificial blood vessels next to artery. Seven patients with upper extremity discomfort were examined by ultrasonography. One case was serum swollen. Three cases were thrombosis in artificial vessels. One case was pseudoaneurysm. Two cases were edema. Conclusions Ultrasonography plays a significant clinic role in testing artificial vascular graft for arteriovenous fistula and its complications.%目的 探讨彩色多普勒超声对人工血管移植动静脉瘘及其并发症的检测价值.方法 对18例人工血管移植动静脉瘘术后4~6周的患者,应用彩色多普勒超声测量动脉侧吻合口和移植人工血管动脉端内径、峰值流速和血流量,同时对上肢出现不适症状患者进行超声检测.结果 术后4~6周彩色多普勒超声显示吻合口和移植人工血管血流充盈良好,动脉侧吻合口内径、峰值流速和血流量分别为(3.61±0.68)mm、(298

  14. Denatured Autologous Muscle Graft Combining PLGA Nerve Guide Conduits in Repairing Peripheral Nerve Defects%神经导管联合自体变性肌桥修复大鼠周围神经缺损的实验研究

    Institute of Scientific and Technical Information of China (English)

    李政; 周明

    2012-01-01

    Objective To explore the feasibility of denatured autologous muscle graft combining PLGA Nerve guide conduits in repairing sciatic: nerve defects in rats. Methods Forty-five Sprague-Dawley rats were randomly divided inlo three groups (n=15) and the left sciatic nerve defects model was established on each rat. Autologous nerve (group A), PLGA nerve guide conduits (group B) and denatured autologous muscle graft combining PLGA nerve guide conduits (group C) were used to bridge the nerve defects. Microscopic observation, sciatic nerve function index,recovery rate of gastrocnemius wet weight, histological observation and computerized imaging analysis were carried out postoperatively. Results 'flie findings showed that denatured autologous muscle graft combining nerve guide conduits was better than nerve guide conduits, but less effective than autologous nerve transplantation. Conclusion Denatured autologous muscle graft combining nerve guide conduits can promote the peripheral nerve regeneration and repair nerve defects.%目的 探讨PLGA神经导管联合化学萃取的自体骨骼肌肌桥,修复大鼠坐骨神经缺损的可能性.方法 SD大鼠45只,建立大鼠左侧坐骨神经缺损模型.随机分为3组,分别采用自体神经(A组)、PLGA神经导管(B组)和PLGA神经导管联合化学萃取自体骨骼肌肌桥(C组),来修复神经缺损.术后通过大体观察、坐骨神经功能指数测定、腓肠肌湿质量恢复率测定、组织学观察和图像分析对比等,检测神经缺损修复情况.结果 神经导管联合化学萃取白体骨骼肌肌桥能促进坐骨神经再生,各项指标均优于单纯神经导管移植,但是效果略差于自体神经移植.结论 PLGA神经导管联合化学萃取自体骨骼肌肌桥,对大鼠坐骨神经缺损具有良好的桥梁作用和促神经生长的作用.

  15. Characterization and Schwann Cell Seeding of up to 15.0 cm Long Spider Silk Nerve Conduits for Reconstruction of Peripheral Nerve Defects

    Directory of Open Access Journals (Sweden)

    Tim Kornfeld

    2016-11-01

    Full Text Available Nerve reconstruction of extended nerve defect injuries still remains challenging with respect to therapeutic options. The gold standard in nerve surgery is the autologous nerve graft. Due to the limitation of adequate donor nerves, surgical alternatives are needed. Nerve grafts made out of either natural or artificial materials represent this alternative. Several biomaterials are being explored and preclinical and clinical applications are ongoing. Unfortunately, nerve conduits with successful enhancement of axonal regeneration for nerve defects measuring over 4.0 cm are sparse and no conduits are available for nerve defects extending to 10.0 cm. In this study, spider silk nerve conduits seeded with Schwann cells were investigated for in vitro regeneration on defects measuring 4.0 cm, 10.0 cm and 15.0 cm in length. Schwann cells (SCs were isolated, cultured and purified. Cell purity was determined by immunofluorescence. Nerve grafts were constructed out of spider silk from Nephila edulis and decellularized ovine vessels. Finally, spider silk implants were seeded with purified Schwann cells. Cell attachment was observed within the first hour. After 7 and 21 days of culture, immunofluorescence for viability and determination of Schwann cell proliferation and migration throughout the conduits was performed. Analyses revealed that SCs maintained viable (>95% throughout the conduits independent of construct length. SC proliferation on the spider silk was determined from day 7 to day 21 with a proliferation index of 49.42% arithmetically averaged over all conduits. This indicates that spider silk nerve conduits represent a favorable environment for SC attachment, proliferation and distribution over a distance of least 15.0 cm in vitro. Thus spider silk nerve implants are a highly adequate biomaterial for nerve reconstruction.

  16. Characterization and Schwann Cell Seeding of up to 15.0 cm Long Spider Silk Nerve Conduits for Reconstruction of Peripheral Nerve Defects.

    Science.gov (United States)

    Kornfeld, Tim; Vogt, Peter M; Bucan, Vesna; Peck, Claas-Tido; Reimers, Kerstin; Radtke, Christine

    2016-11-30

    Nerve reconstruction of extended nerve defect injuries still remains challenging with respect to therapeutic options. The gold standard in nerve surgery is the autologous nerve graft. Due to the limitation of adequate donor nerves, surgical alternatives are needed. Nerve grafts made out of either natural or artificial materials represent this alternative. Several biomaterials are being explored and preclinical and clinical applications are ongoing. Unfortunately, nerve conduits with successful enhancement of axonal regeneration for nerve defects measuring over 4.0 cm are sparse and no conduits are available for nerve defects extending to 10.0 cm. In this study, spider silk nerve conduits seeded with Schwann cells were investigated for in vitro regeneration on defects measuring 4.0 cm, 10.0 cm and 15.0 cm in length. Schwann cells (SCs) were isolated, cultured and purified. Cell purity was determined by immunofluorescence. Nerve grafts were constructed out of spider silk from Nephila edulis and decellularized ovine vessels. Finally, spider silk implants were seeded with purified Schwann cells. Cell attachment was observed within the first hour. After 7 and 21 days of culture, immunofluorescence for viability and determination of Schwann cell proliferation and migration throughout the conduits was performed. Analyses revealed that SCs maintained viable (>95%) throughout the conduits independent of construct length. SC proliferation on the spider silk was determined from day 7 to day 21 with a proliferation index of 49.42% arithmetically averaged over all conduits. This indicates that spider silk nerve conduits represent a favorable environment for SC attachment, proliferation and distribution over a distance of least 15.0 cm in vitro. Thus spider silk nerve implants are a highly adequate biomaterial for nerve reconstruction.

  17. 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

  18. Axonal regeneration and remyelination evaluation of chitosan/gelatin-based nerve guide combined with transforming growth factor-β1 and Schwann cells.

    Science.gov (United States)

    Nie, Xin; Deng, Manjing; Yang, Maojin; Liu, Luchuan; Zhang, Yongjie; Wen, Xiujie

    2014-01-01

    Despite efforts in peripheral nerve injury and regeneration, it is difficult to achieve a functional recovery following extended peripheral nerve lesions. Even if artificial nerve conduit, cell components and growth factors can enhance nerve regeneration, integration in peripheral nerve repair and regeneration remains yet to be explored. For this study, we used chitosan/gelatin nerve graft constructed with collagenous matrices as a vehicle for Schwann cells and transforming growth factor-β1 to bridge a 10-mm gap of the sciatic nerve and explored the feasibility of improving regeneration and reinnervation in rats. The nerve regeneration was assessed with functional recovery, electrophysiological test, retrograde labeling, and immunohistochemistry analysis during the post-operative period of 16 weeks. The results showed that the internal sides of the conduits were compact enough to prevent the connective tissues from ingrowth. Nerve conduction velocity, average regenerated myelin area, and myelinated axon count were similar to those treated with autograft (p > 0.05) but significantly higher than those bridged with chitosan/gelatin nerve graft alone (p regeneration and remyelination. A designed graft incorporating all of the tissue-engineering strategies for peripheral nerve regeneration may provide great progress in tissue engineering for nerve repair.

  19. Protein selective adsorption properties of a polyethylene terephtalate artificial ligament grafted with poly(sodium styrene sulfonate) (polyNaSS): correlation with physicochemical parameters of proteins.

    Science.gov (United States)

    Lessim, S; Oughlis, S; Lataillade, J J; Migonney, V; Changotade, S; Lutomski, D; Poirier, F

    2015-12-14

    Immediately after surgical placement of biomaterials, a first step consists in the adsorption of proteins from the biological environment on the artificial surfaces. Because the composition of the adsorbed protein layer modulates the cell response to the implanted material, researchers in the biomaterials field have focused on coating proteins or peptides onto surfaces to improve cell response and therefore the long-term compatibility of the implant. However, some materials used in tissue engineering, mainly synthetic polymers, are too hydrophobic to allow the optimal adsorption of proteins and have to be first submitted to physical or chemical treatments. In our laboratory, we have demonstrated that grafting of poly(sodium styrene sulfonate) (polyNaSS) onto biomaterials can strongly modulate the protein adsorption and the cellular response compared to unmodified surfaces. In this study, we used a liquid chromatography strategy coupled to proteomics to evaluate the adsorptive properties of a polyethylene terephtalate (PET) artificial ligament grafted with polyNaSS, and to identify and analyse proteins adsorbed on PET fibers. Results obtained with platelet rich plasma (PRP) proteins demonstrated that grafting significantly increases the protein adsorption of the PET and also selectively modulates the adsorption of proteins on PET fibers. Finally, regarding physicochemical parameters calculated from the amino acid sequence of identified proteins, we found that the aliphatic index is highly correlated with the selective adsorption of proteins onto the polyNaSS/PET surface. Therefore, the proteomic approach complemented with physicochemical property evaluation could provide a powerful tool for the elaboration of new biomaterials based on protein layer deposition.

  20. The Effect of Electrospun Gelatin Fibers Alignment on Schwann Cell and Axon Behavior and Organization in the Perspective of Artificial Nerve Design.

    Science.gov (United States)

    Gnavi, Sara; Fornasari, Benedetta Elena; Tonda-Turo, Chiara; Laurano, Rossella; Zanetti, Marco; Ciardelli, Gianluca; Geuna, Stefano

    2015-01-01

    Electrospun fibrous substrates mimicking extracellular matrices can be prepared by electrospinning, yielding aligned fibrous matrices as internal fillers to manufacture artificial nerves. Gelatin aligned nano-fibers were prepared by electrospinning after tuning the collector rotation speed. The effect of alignment on cell adhesion and proliferation was tested in vitro using primary cultures, the Schwann cell line, RT4-D6P2T, and the sensory neuron-like cell line, 50B11. Cell adhesion and proliferation were assessed by quantifying at several time-points. Aligned nano-fibers reduced adhesion and proliferation rate compared with random fibers. Schwann cell morphology and organization were investigated by immunostaining of the cytoskeleton. Cells were elongated with their longitudinal body parallel to the aligned fibers. B5011 neuron-like cells were aligned and had parallel axon growth when cultured on the aligned gelatin fibers. The data show that the alignment of electrospun gelatin fibers can modulate Schwann cells and axon organization in vitro, suggesting that this substrate shows promise as an internal filler for the design of artificial nerves for peripheral nerve reconstruction.

  1. Effects of mature adipocyte-derived dedifferentiated fat (DFAT) cells on generation and vascularisation of dermis-like tissue after artificial dermis grafting.

    Science.gov (United States)

    Soejima, Kazutaka; Kashimura, Tsutomu; Asami, Takashi; Kazama, Tomohiko; Matsumoto, Taro; Nakazawa, Hiroaki

    2015-02-01

    Although artificial dermis (AD) is effective for skin reconstruction, it requires two separate procedures, because the AD must be vascularised before skin grafts. To shorten the period of the dermis-like tissue generation before the secondary skin grafting must be beneficial. Dedifferentiated fat (DFAT) cells are isolated from mature adipose cell suspensions and have potential to differentiate into multiple cell types including endothelial cells. This study aimed to investigate effects of DFAT cells on dermal regeneration after AD grafts in rats. The effects of combination use of DFAT cells and basic fibroblast growth factor (bFGF) were also tested to mimic clinical situations. DFAT cells were isolated from SD rats. Full-thickness wounds were created on the back of rats followed by AD grafting. Five groups were established; Group I: control, Group II: treated with DFAT cells, Group III: treated with bFGF, Group IV: treated with both of DFAT cells and bFGF, and Group V: treated with Green fluorescent protein (GFP)-labelled DFAT cells and bFGF. Histological evaluation was serially performed. Group IV showed markedly promoted vascularisation of dermis-like tissue. In particular, capillary infiltration into the dermis was obtained within 2 days. Immunohistochemical examination revealed that the transplanted DFAT cells had differentiated into endothelial cells and participated in angiogenesis. Group IV also showed a marked increase in the thickness of the dermis like tissue. The present results suggest that the use of DFAT cells under bFGF treatment could be beneficial to shorten the period required for dermal regeneration and vascularisation and contribute to use AD more effectively and safely.

  2. Computational estimation of fluid mechanical benefits from a fluid deflector at the distal end of artificial vascular grafts.

    Science.gov (United States)

    Roos, M W; Wadbro, E; Berggren, M

    2013-02-01

    Intimal hyperplasia at the distal anastomosis is considered to be an important determinant for arterial and arteriovenous graft failure. The connection between unhealthy hemodynamics and intimal hyperplasia motivates the use of computational fluid dynamics modeling to search for improved graft design. However, studies on the fluid mechanical impact on intimal hyperplasia at the suture line intrusion have previously been scanty. In the present work, we focus on intimal hyperplasia at the suture line and illustrate potential benefits from the introduction of a fluid deflector to shield the suture line from unhealthily high wall shear stress.

  3. Post-ischaemic angiogenic therapy using in vivo prevascularized ascorbic acid-enriched myocardial artificial grafts improves heart function in a rat model.

    Science.gov (United States)

    Martinez, Eliana C; Wang, Jing; Lilyanna, Shera; Ling, Lieng H; Gan, Shu U; Singh, Rajeev; Lee, Chuen N; Kofidis, Theo

    2013-03-01

    Angiogenesis plays a key role in post-ischaemic myocardial repair. We hypothesized that epicardial implantation of an ascorbic acid (AA)-enriched myocardial artificial graft (MAG), which has been prevascularized in the recipients' own body, promotes restoration of the ischaemic heart. Gelatin patches were seeded with GFP-luciferase-expressing rat cardiomyoblasts and enriched with 5 μm AA. Grafts were prevascularized in vivo for 3 days, using a renal pouch model in rats. The MAG patch was then implanted into the same rat's ischaemic heart following myocardial infarction (MI). MAG-treated animals (MAG group, n = 6) were compared to untreated infarcted animals as injury controls (MI group, n = 6) and sham-operated rats as healthy controls (healthy group, n = 7). In vivo bioluminescence imaging indicated a decrease in donor cell survival by 83% during the first week post-implantation. Echocardiographic and haemodynamic assessment 4 weeks after MI revealed that MAG treatment attenuated left ventricular (LV) remodelling (LV end-systolic volume, 0.31 ± 0.13 vs 0.81 ± 0.01 ml, p hearts, attenuated LV remodelling and preserved LV function.

  4. Chitosan-cross-linked nanofibrous PHBV nerve guide for rat sciatic nerve regeneration across a defect bridge.

    Science.gov (United States)

    Biazar, Esmaeil; Keshel, Saeed Heidari

    2013-01-01

    The aim of this study was to produce a chitosan-cross-linked nanofibrous biodegradable poly (3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit. The artificial nerve scaffold designed by electrospinning method and cross-linked with chitosan by chemical method. Afterwards, the scaffolds were evaluated by microscopic, physical, and mechanical analyses and cell culture assays with Schwann cells. The conduits were implanted into a 10 mm gap in the sciatic nerves of the rats. Four months after surgery, the regenerated nerves were evaluated by macroscopic assessments and histology. This polymeric conduit had sufficiently good mechanical properties to serve as a nerve guide. Cellular experiments showed a better cell adhesion, growth, and proliferation inside the cross-linked nanofibrous scaffolds compared with un-cross-linked ones, also Schwann cells well attached on chitosan-cross-linked nanofibrous surface. The in vivo results demonstrated that in the nanofibrous graft, the sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. This neural conduit appears to have the right organization for testing in vivo nerve tissue engineering studies.

  5. 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.

  6. 携带eNOS基因的小口径人工血管在犬的体内研究%Study on small diameter artificial vascular graft with eNOS gene transfected endothelial cells in canine

    Institute of Scientific and Technical Information of China (English)

    薛冠华; 张纪蔚; 张皓; 张柏根

    2008-01-01

    目的 观察转染内皮型一氧化氮合酶(eNOS)基因的内皮细胞(EC)种植小口径人工血管在实验犬体内的通畅效果.方法 采用"高压灌注两步法"将转染eNOS基因的EC种植于3 mm人工血管;并植入实验犬股动脉,分1、4、12、24周行数字减影血管造影(DSA)、扫描电镜和透射电镜观察植入后情况.结果 转染eNOS基因的EC种植3 mm人工血管,贴附率在90%以上;10 d左右延伸为一层完整连续的内膜.植入犬体内后1周,单纯人工血管组1/3(3/9)血管阻塞;术后4周,单纯人工血管组全部阻塞(9/9),未转染组近半数阻塞(5/10、4/9);术后12周,单纯人工血管组全部阻塞,未转染组几乎全部阻塞(9/9、9/10);术后24周,未转染组全部阻塞,eNOS转染组8/10通畅.电镜检查表明,eNOS转染组人工血管腔面EC排列紧密,形成一层连续完整的内膜,仅见少许红细胞、血小板及白细胞沉积.结论 转染eNOS基因的EC种植小口径人工血管效果满意,植入实验犬体内后通畅效果良好.%Objective To investigate the patency efficacy of small diameter artificial vascular graft with eNOS gene transfected endothelial cells in canine. Methods By using the two steps high pressure injection, eNOS gene transfected endothelial cells were planted on artificial vascular graft with a diameter of 3 mm. The artificial vascular grafts were transplanted into canine femoral artery, and the patency of the artery was observed through digital subtracted angiography (DSA) and electron telescope 1, 4, 12 and 24 weeks after the operation. Results The adherence rate of eNOS gene transfected endothelial cells to artificial vascular grafts was up to 90%. For 10 days, the cells extended and formed a continuous intima. One week after the operation, 3/9 grafts were obstructed in the group of simple artificial vascular grafts; 4 weeks after, all of grafts (9/9) were obstructed in the group of simple artificial vascular grafts and almost half grafts (5

  7. Sensory Recovery Outcome after Digital Nerve Repair in Relation to Different Reconstructive Techniques: Meta-Analysis and Systematic Review

    Directory of Open Access Journals (Sweden)

    Felix J. Paprottka

    2013-01-01

    Full Text Available Good clinical outcome after digital nerve repair is highly relevant for proper hand function and has a significant socioeconomic impact. However, level of evidence for competing surgical techniques is low. The aim is to summarize and compare the outcomes of digital nerve repair with different methods (end-to-end and end-to-side coaptations, nerve grafts, artificial conduit-, vein-, muscle, and muscle-in-vein reconstructions, and replantations to provide an aid for choosing an individual technique of nerve reconstruction and to create reference values of standard repair for nonrandomized clinical studies. 87 publications including 2,997 nerve repairs were suitable for a precise evaluation. For digital nerve repairs there was practically no particular technique superior to another. Only end-to-side coaptation had an inferior two-point discrimination in comparison to end-to-end coaptation or nerve grafting. Furthermore, this meta-analysis showed that youth was associated with an improved sensory recovery outcome in patients who underwent digital replantation. For end-to-end coaptations, recent publications had significantly better sensory recovery outcomes than older ones. Given minor differences in outcome, the main criteria in choosing an adequate surgical technique should be gap length and donor site morbidity caused by graft material harvesting. Our clinical experience was used to provide a decision tree for digital nerve repair.

  8. Biological artificial vessel graft in distal arterial bypass for treating diabetic lower limb ischemia: a case report

    Institute of Scientific and Technical Information of China (English)

    GU Yong-quan; WU Ying-feng; QI Li-xing; GUO Lian-ri; LI Xue-feng; CUI Shi-jun; TONG Zhu; GUO Jian-ming; ZHANG Jian

    2011-01-01

    A 68-year-old female patient was treated for unhealed ulcer in the fourth toe of the left foot. Clinical examinations identified severe stenosis of the proximal segment and occlusion of the distal segment of the left anterior tibial artery, and occlusion of the left posterior tibial artery and the peroneal artery. The proximal stenotic segment of the left anterior tibial artery was dilated, but the distal occlusive part failed to be re-canalized. Left anterior tibial artery to dorsal pedal artery bypass was performed on the patient with an epoxide-crosslinked, special radicals antigen-sealed, porcine-derived biological graft; debridement of the left 4th digiti pedis was also performed. Postoperation course was uneventful. The pulse of the left dorsal pedal artery was strong. The ankle brachial index (ABI) increased from 0.60 to 1.09. Warfarin and two antiplatelet drugs were given after the operation. Six months after operation, computed tomographic angiogram (CTA)identified the patent graft.

  9. Acellular nerve allograft promotes selective regeneration

    Institute of Scientific and Technical Information of China (English)

    Haili Xin; Guanjun Wang; Xinrong He; Jiang Peng; Quanyi Guo; Wenjing Xu

    2011-01-01

    Acellular nerve allograft preserves the basilar membrane tube and extracellular matrix, which pro-motes selective regeneration of neural defects via bridging. In the present study, a Sprague Dawley rat sciatic nerve was utilized to prepare acellular nerve allografts through the use of the chemical extraction method. Subsequently, the allograft was transplanted into a 10-mm sciatic nerve defect in Wistar rats, while autologous nerve grafts from Wistar rats served as controls. Compared with autologous nerve grafts, the acellular nerve allografts induced a greater number of degenerated nerve fibers from sural nerves, as well as a reduced misconnect rate in motor fibers, fewer acetyl-choline esterase-positive sural nerves, and a greater number of carbonic anhydrase-positive senso-ry nerve fibers. Results demonstrated that the acellular nerve allograft exhibited significant neural selective regeneration in the process of bridging nerve defects.

  10. The nursing of microvascular arterialized venous pedicle sural nerve grafting in repairing antebrachium nerve defect%小隐静脉蒂动脉化游离腓肠神经移植修复前臂神经缺损的护理

    Institute of Scientific and Technical Information of China (English)

    朱玉花; 张全英

    2010-01-01

    探讨小隐静脉蒂动脉化游离腓肠神经移植修复前臂神经缺损的围手术期护理.采用带小隐静脉蒂的腓肠神经移植修复前臂神经损伤30例,术前进行必要准备及心理支持等护理,术后密切观察病情,预防血管危象及低血容量休克,积极康复锻炼.30例患者上肢周围神经功能评定优良率达83.3%.小隐静脉蒂动脉化游离腓肠神经移植修复前臂神经缺损疗效满意,术前术后有效的护理支持是获得满意疗效的必要因素.%To study the microvascular arterialized venous pedicle sural nerve grafting in repairing antebrachium nerve defect. Thirty cases with antebrachium nerve defect were cured by microvascular arterialized venous pedicle sural nerve grafting. All patients were cared with necessary preparations and psychological support before surgery, close observation after surgery, vascular crisis and hypovolemic shock were prevented and rehabilitation exercises were active. The effective rate was 83.3%. Effective patient care is a key factor in curing the disease.

  11. 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.

  12. 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

  13. 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...

  14. An experimental study peripheral nerve regeneration through NGF · HAMM grafts in rats%含神经生长因子的羊膜基质管桥接修复神经缺损的实验研究

    Institute of Scientific and Technical Information of China (English)

    王平; 彭学良; 刘晋才

    2001-01-01

    Objective To determine the effect of peripheral nerve regeneration through NGF ·HAMM (Nerve growth factor and Human Ammion membrane Matrix) grafts. Methods A 1.2 cm defect of the left sciatic nerve were made and then repaired randomly by means of autogenous nerve bridging (group N),NGF · HAMM microporous conduit bridging (group NH) or HAMM microporous conduit bridging (group H) in 60 adult Wistar rats. There were 20 animals in every group. At 1,2 and 3months post operation,the following items as qualitative histology,quatitative histomorphometry,electrophysiology and functional assessments of end-organ reconnection were determined. Results At 2and 3 months post operation,Motor nerve conduction velocity (MNCV) of the nerve repaired with HAMM were lower than that of the nerve repaired with autograft and NGF · HAMM. At 3 months post operation,there was no significant difference between NH group and N group in nerve conduction velocity (P>0. 05). At 2 and 3 months post operation,both NGF · HAMM conduit and nerve autograft groups showed more nerve fibers,bigger axon diameter and thicker meylin sheaths than H group.Conclution The combination of HAMM and NGF world enhance nerve regeneration and myeliogeny,as well as could cooperatively promote the functional recovery of injured nerves and limbs. Our results indicate that the NGF · HAMM microporous conduit is a promising tool for use as a nerve guide tube in peripheral nerve regeneration.%目的研究含神经生长因子的人羊膜基质微孔管(NGF·HAMM)、桥接修复周围神经缺损的效果。方法分别用含神经生长因子的人羊膜基质微孔管(NGF·HAMM)、人羊膜基质微孔管(HAMM)、自体神经移植修复60只Wistar大鼠坐骨神经1.2 cm缺损;同时将大鼠按手术方法分为3组,每组20只。术后进行组织形态学、电生理学、伤肢功能恢复等检测。结果近端神经再生轴突生长通过1.2 cm长的NGF·HAMM移植体,重新支配终末骨骼肌,其再

  15. Nerve grafting and neuromuscular transfers.

    Science.gov (United States)

    Carroll, W R

    1994-02-01

    In today's otolaryngology practice, surgeons frequently encounter situations in which soft-tissue augmentation is needed. Traditionally, fat, fascia, and nonvascularized muscle have been used for these purposes. This article reviews the history as well as the current applications and limitations of these materials. Although not ideal in all circumstances, these materials remain useful in selected situations.

  16. 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

  17. Repair of sciatic nerve defects using tissue engineered nerves*

    Institute of Scientific and Technical Information of China (English)

    Caishun Zhang; Gang Lv

    2013-01-01

    In this study, we constructed tissue-engineered nerves with acel ular nerve al ografts in Sprague-Dawley rats, which were prepared using chemical detergents-enzymatic digestion and mechanical methods, in combination with bone marrow mesenchymal stem cel s 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 tis-sue-engineered nerves was similar to that after autologous nerve grafting, and was higher than that after repair with acel ular nerve al ografts. Immunohistochemical staining revealed that motor endplates with acetylcholinesterase-positive nerve fibers were orderly arranged in the middle and superior parts of the gastrocnemius muscle;regenerated nerve tracts and sprouted branches were connected with motor endplates, as shown by acetylcholinesterase histochemistry combined with silver staining. The wet weight ratio of the tibialis anterior muscle at the affected contralateral hind limb was similar to the sciatic nerve after repair with autologous nerve grafts, and higher than that after repair with acel ular nerve al ografts. The hind limb motor function at the affected side was significantly improved, indicating that acel ular nerve al ografts combined with bone marrow me-senchymal stem cel bridging could promote functional recovery of rats with sciatic nerve defects.

  18. 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.

  19. Cadaveric nerve allotransplantation in the treatment of persistent thoracic neuralgia.

    Science.gov (United States)

    Barbour, John R; Yee, Andrew; Moore, Amy M; Trulock, Elbert P; Buchowski, Jacob M; Mackinnon, Susan E

    2015-04-01

    When relief from neuralgia cannot be achieved with traditional methods, neurectomy may be considered to abate the stimulus, and primary opposition of the terminal nerve ending is recommended to prevent neuroma. Nerve repair with autograft is limited by autologous nerves available for large nerve defects. Cadaveric allografts provide an unlimited graft source without donor-site morbidities, but are rapidly rejected unless appropriate immunosuppression is achieved. An optimal treatment method for nerve allograft transplantation would minimize rejection while simultaneously permitting nerve regeneration. This report details a novel experience of nerve allograft transplantation using cadaveric nerve grafts to desensitize persistent postoperative thoracic neuralgia.

  20. 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.

  1. 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.

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

    Institute of Scientific and Technical Information of China (English)

    Wei-ling Cui; Long-hai Qiu; Jia-yan Lian; Jia-chun Li; Jun Hu; Xiao-lin Liu

    2016-01-01

    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.

  3. A Silk Fibroin/Collagen Nerve Scaffold Seeded with a Co-Culture of Schwann Cells and Adipose-Derived Stem Cells for Sciatic Nerve Regeneration.

    Directory of Open Access Journals (Sweden)

    Yunqiang Xu

    Full Text Available As a promising alternative to autologous nerve grafts, tissue-engineered nerve grafts have been extensively studied as a way to bridge peripheral nerve defects and guide nerve regeneration. The main difference between autogenous nerve grafts and tissue-engineered nerve grafts is the regenerative microenvironment formed by the grafts. If an appropriate regenerative microenvironment is provided, the repair of a peripheral nerve is feasible. In this study, to mimic the body's natural regenerative microenvironment closely, we co-cultured Schwann cells (SCs and adipose-derived stem cells (ADSCs as seed cells and introduced them into a silk fibroin (SF/collagen scaffold to construct a tissue-engineered nerve conduit (TENC. Twelve weeks after the three different grafts (plain SF/collagen scaffold, TENC, and autograft were transplanted to bridge 1-cm long sciatic nerve defects in rats, a series of electrophysiological examinations and morphological analyses were performed to evaluate the effect of the tissue-engineered nerve grafts on peripheral nerve regeneration. The regenerative outcomes showed that the effect of treatment with TENCs was similar to that with autologous nerve grafts but superior to that with plain SF/collagen scaffolds. Meanwhile, no experimental animals had inflammation around the grafts. Based on this evidence, our findings suggest that the TENC we developed could improve the regenerative microenvironment and accelerate nerve regeneration compared to plain SF/collagen and may serve as a promising strategy for peripheral nerve repair.

  4. A Silk Fibroin/Collagen Nerve Scaffold Seeded with a Co-Culture of Schwann Cells and Adipose-Derived Stem Cells for Sciatic Nerve Regeneration.

    Science.gov (United States)

    Xu, Yunqiang; Zhang, Zhenhui; Chen, Xuyi; Li, Ruixin; Li, Dong; Feng, Shiqing

    2016-01-01

    As a promising alternative to autologous nerve grafts, tissue-engineered nerve grafts have been extensively studied as a way to bridge peripheral nerve defects and guide nerve regeneration. The main difference between autogenous nerve grafts and tissue-engineered nerve grafts is the regenerative microenvironment formed by the grafts. If an appropriate regenerative microenvironment is provided, the repair of a peripheral nerve is feasible. In this study, to mimic the body's natural regenerative microenvironment closely, we co-cultured Schwann cells (SCs) and adipose-derived stem cells (ADSCs) as seed cells and introduced them into a silk fibroin (SF)/collagen scaffold to construct a tissue-engineered nerve conduit (TENC). Twelve weeks after the three different grafts (plain SF/collagen scaffold, TENC, and autograft) were transplanted to bridge 1-cm long sciatic nerve defects in rats, a series of electrophysiological examinations and morphological analyses were performed to evaluate the effect of the tissue-engineered nerve grafts on peripheral nerve regeneration. The regenerative outcomes showed that the effect of treatment with TENCs was similar to that with autologous nerve grafts but superior to that with plain SF/collagen scaffolds. Meanwhile, no experimental animals had inflammation around the grafts. Based on this evidence, our findings suggest that the TENC we developed could improve the regenerative microenvironment and accelerate nerve regeneration compared to plain SF/collagen and may serve as a promising strategy for peripheral nerve repair.

  5. An anatomical study of porcine peripheral nerve and its potential use in nerve tissue engineering

    Science.gov (United States)

    Zilic, Leyla; Garner, Philippa E; Yu, Tong; Roman, Sabiniano; Haycock, John W; Wilshaw, Stacy-Paul

    2015-01-01

    Current nerve tissue engineering applications are adopting xenogeneic nerve tissue as potential nerve grafts to help aid nerve regeneration. However, there is little literature that describes the exact location, anatomy and physiology of these nerves to highlight their potential as a donor graft. The aim of this study was to identify and characterise the structural and extracellular matrix (ECM) components of porcine peripheral nerves in the hind leg. Methods included the dissection of porcine nerves, localisation, characterisation and quantification of the ECM components and identification of nerve cells. Results showed a noticeable variance between porcine and rat nerve (a commonly studied species) in terms of fascicle number. The study also revealed that when porcine peripheral nerves branch, a decrease in fascicle number and size was evident. Porcine ECM and nerve fascicles were found to be predominately comprised of collagen together with glycosaminoglycans, laminin and fibronectin. Immunolabelling for nerve growth factor receptor p75 also revealed the localisation of Schwann cells around and inside the fascicles. In conclusion, it is shown that porcine peripheral nerves possess a microstructure similar to that found in rat, and is not dissimilar to human. This finding could extend to the suggestion that due to the similarities in anatomy to human nerve, porcine nerves may have utility as a nerve graft providing guidance and support to regenerating axons. PMID:26200940

  6. An anatomical study of porcine peripheral nerve and its potential use in nerve tissue engineering.

    Science.gov (United States)

    Zilic, Leyla; Garner, Philippa E; Yu, Tong; Roman, Sabiniano; Haycock, John W; Wilshaw, Stacy-Paul

    2015-09-01

    Current nerve tissue engineering applications are adopting xenogeneic nerve tissue as potential nerve grafts to help aid nerve regeneration. However, there is little literature that describes the exact location, anatomy and physiology of these nerves to highlight their potential as a donor graft. The aim of this study was to identify and characterise the structural and extracellular matrix (ECM) components of porcine peripheral nerves in the hind leg. Methods included the dissection of porcine nerves, localisation, characterisation and quantification of the ECM components and identification of nerve cells. Results showed a noticeable variance between porcine and rat nerve (a commonly studied species) in terms of fascicle number. The study also revealed that when porcine peripheral nerves branch, a decrease in fascicle number and size was evident. Porcine ECM and nerve fascicles were found to be predominately comprised of collagen together with glycosaminoglycans, laminin and fibronectin. Immunolabelling for nerve growth factor receptor p75 also revealed the localisation of Schwann cells around and inside the fascicles. In conclusion, it is shown that porcine peripheral nerves possess a microstructure similar to that found in rat, and is not dissimilar to human. This finding could extend to the suggestion that due to the similarities in anatomy to human nerve, porcine nerves may have utility as a nerve graft providing guidance and support to regenerating axons.

  7. 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

  8. Clinical significance of suprascapular nerve mobilization.

    Science.gov (United States)

    Bodily, Kale D; Spinner, Robert J; Shin, Alexander Y; Bishop, Allen T

    2005-11-01

    The anatomy of the suprascapular nerve is important to surgeons when focal nerve lesions necessitate surgical repair. Recent experience with a patient who had a complete suprascapular nerve lesion in the retroclavicular region (combined with axillary and musculocutaneous nerve lesions) is presented to illustrate that successful direct nerve repair is possible despite resection of a neuroma. Specifically, we found that neurolysis and mobilization of the suprascapular nerve and release of the superior transverse scapular ligament provided the necessary nerve length to achieve direct nerve repair after the neuroma was removed. A combined supraclavicular and infraclavicular approach to the suprascapular nerve provided excellent visualization, especially in the retroclavicular region. Postoperatively, the patient recovered complete shoulder abduction and external rotation with the direct repair, an outcome uncommonly achieved with interpositional grafting. Based on our operative experience, we set out to quantify the length that the suprascapular nerve could be mobilized with neurolysis. Mobilization of the nerve and release of the superior transverse scapular ligament generated an average of 1.6 cm and 0.7 cm of extra nerve length respectively, totaling 2.3 cm of additional usable nerve length overall. The ability to expose the suprascapular nerve in the retroclavicular/infraclavicular region and to mobilize the suprascapular nerve for possible direct repair has not been previously emphasized and is clinically important. This surgical approach and technique permits direct nerve repair after resection of a focal neuroma in the retroclavicular or infraclavicular region, thus avoiding interpositional grafting, and improving outcomes.

  9. 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

  10. Comparative neuro tissue engineering using different nerve guide implants.

    Science.gov (United States)

    Sinis, N; Schaller, H E; Schulte-Eversum, C; Lanaras, T; Schlosshauer, B; Doser, M; Dietz, K; Rösner, H; Müller, H W; Haerle, M

    2007-01-01

    At the moment autologous nerve grafting remains the only reasonable technique for reconstruction of peripheral nerve defects. Unfortunately, this technique has a lot of complications and disadvantages. These problems are related to the autologous nerve that is harvested for this procedure. Donor site morbidity with loss of sensitivity, painful neuroma formation and of course the restricted availability of autologous nerves stimulates the idea for alternative techniques on that field. In this paper we describe our experience with different graft materials for reconstruction of a 2 cm nerve gap in a median nerve model in rats. After implantation of various materials (biological/synthetic) the main experiments were conducted with a synthetic, biodegradable nerve conduit seeded with autologous Schwann cells. With this material we were able to reconstruct successfully a 2 cm gap in the rat median nerve. Regeneration with this material was found to be equally to an autologous nerve graft.

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

    Institute of Scientific and Technical Information of China (English)

    Ying Liu; Xun-cheng Xu; Yi Zou; Su-rong Li; Bin Zhang; Yue Wang

    2015-01-01

    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 per-formed 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 conduc-tion 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 regener-ated potentials ifrst 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 ‘ex-cellent’ 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 func-tional recovery of a transplanted nerve can be dynamically observed after the surgery.

  12. Acetabular defect reconstruction with impacted morsellized bone grafts or TCP/HA particles. A study on the mechanical stability of cemented cups in an artificial acetabulum model.

    NARCIS (Netherlands)

    Bolder, S.B.T.; Verdonschot, N.J.J.; Schreurs, B.W.; Buma, P.

    2002-01-01

    In revision surgery of the acetabulum bone defects can be filled with impacted human morsellized bone grafts. Because of a worldwide limited availability of human bone, alternatives are being considered. In this study we compared the initial stability of acetabular cups after reconstructing a cavita

  13. Post-explant visualization of thrombi in outflow grafts and their junction to a continuous-flow total artificial heart using a high-definition miniaturized camera.

    Science.gov (United States)

    Karimov, Jamshid H; Horvath, David; Sunagawa, Gengo; Byram, Nicole; Moazami, Nader; Golding, Leonard A R; Fukamachi, Kiyotaka

    2015-12-01

    Post-explant evaluation of the continuous-flow total artificial heart in preclinical studies can be extremely challenging because of the device's unique architecture. Determining the exact location of tissue regeneration, neointima formation, and thrombus is particularly important. In this report, we describe our first successful experience with visualizing the Cleveland Clinic continuous-flow total artificial heart using a custom-made high-definition miniature camera.

  14. Volar locking compression plate combined with artificial bone grafting for treatment of comminuted distal radial fracture%掌侧锁定加压接骨板结合人工骨植骨治疗桡骨远端骨折

    Institute of Scientific and Technical Information of China (English)

    周凯龙; 王培吉

    2014-01-01

    目的 探讨应用掌侧锁定加压接骨板(LCP)结合人工骨植骨治疗桡骨远端粉碎性骨折的临床疗效.方法 2011年1月至2013年8月期间在我院行掌侧LCP结合人工骨植骨,治疗A3、C2、C3型桡骨远端粉碎性骨折45例.术前及术后测量掌倾角、尺偏角、桡骨轴向短缩及关节面台阶程度.结果 所有患者均获得6~18个月的随访,平均12个月,骨折均获得骨性愈合,人工骨无不良反应;各影像学数据较术前均有明显改善;按Gartland-Werley评分标准评定,A3型优良率为94.4%、C2型优良率为87.5%、C3型优良率为81.8%.结论 应用掌侧LCP结合人工骨植骨治疗A3、C2、C3型桡骨远端粉碎性骨折,能够恢复桡骨长度,获得坚强内固定.%Objective To investigate the clinical results of the application of volar locking compression plate combined with artificial bone grafting in the treatment of comminuted distal radial fractures.Methods From January 2011 to August 2013,45 cases of type A3,type C2 and type C3 comminuted distal radial fractures were treated with volar locking compression plate combined with artificial bone grafting.All the cases were closed fractures with radial shortening or articular surface collapse.Volar tilt angle,radial inclination angle,axial shortening of the radius and extent of joint surface step deformity were measured both pre and post operatively.Results All the patients were follow-up for 6 to 18 months,with an average of 12 months.Bone union was noted in all the cases.There was no adverse reaction to the artificial bone grafts.Radiographic parameters were significantly improved.The clinical results were evaluated using the Gartland-Werley wrist score and rated as excellent and good in 94.4% of type A3 fractures,87.5% of type C2 fractures,and 81.8% of type C3 fractures.Conclusion Applying volar locking compression plate combined with artificial bone grafting can achieve rigid fixation and restore radial length in

  15. 慢性下肢缺血搭桥术后再狭窄分析%A study on restenosis after artificially grafting bypass for chronic ischemia of the lower extremities

    Institute of Scientific and Technical Information of China (English)

    赵克强; 张小明; 沈晨阳; 万峰

    2008-01-01

    目的 探讨慢性下肢缺血患者行人工血管搭桥术后再狭窄的病因及治疗方法.方法 回顾性分析2002年1月至2007年4月收治的慢性下肢缺血患者的临床资料,其中股腘动脉搭桥术后再狭窄行二次手术的52例患者作为实验组,同时随访资料完整的32例搭桥术后人工血管通畅者作为对照组.分析两组问伴随疾病及高危因素,检测血脂、纤维蛋白原及C反应蛋白水平.结果 实验组纤维蛋白原(4.48±1.68)g/L、CRP(9.5±2.6)mg/L、低密度脂蛋白(4.5±1.7)mmol/L高于对照组(3.50±0.72)g/L、(4.0±3.2)mg/L、(2.8±0.9)mmol/L,差异有统计学意义(P<0.01).实验组高密度脂蛋白为(1.02±0.32)mmol/L略低于对照组(1.12±0.28)mmol/L,差异无统计学意义(P>0.05).实验组再次手术中见吻合口处重度内膜增生并继发血栓形成42例,人工血管内原发血栓形成10例.二次术后人工血管保持通畅28例,截肢10例,人工血管感染取出3例,死亡5例.结论 人工血管搭桥术后再狭窄主要原因是吻合口内膜增生.CRP、纤维蛋白原、低密度脂蛋白增高可能是导致吻合口内膜增生、人工血管闭塞的重要高危因素.%Objective To probe the etiology and management of restenosis after artificially grafting bypass for chronic ischemia of the lower extremities. Methods In this study 52 cases suffering from postoperative restenosis and obliteration were compared with 32 cases whose artificial grafts remain patent during the same postoperative follow-up period of 3~62 months.Possible risk factors that lead to restenosis were evaluated.Resuits FIB(4.48±1.68)g/L,CRP(9.5±2.6)mg/L and LDL(4.5±1.7)mmol/L were significantly higher in the restenosis group than FIB(3.50±0.72)g/L,CRP(4.0±3.2)mg/L and LDL(2.8±0.9)mmol/L in the patent group(P<0.01).There were no significant difference between HDL(1.02±0.32)mmol/L in the restenosis group and HDL(1.12±0.28)mmol/L in the patent group (P>0.05).Reoperation

  16. 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

  17. 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 ...

  18. 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.

  19. 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.

  20. 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.

  1. 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)

    Celia eHerrera-Rincon

    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.

  2. 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.

  3. 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

  4. 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.

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

    Science.gov (United States)

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

    2013-07-25

    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 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) conduit-repaired sciatic nerve following tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Following 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 autogenous 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.

  6. 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 orC5-7 avulsion of the brachial plexus with that of using phrenic and spinal accessary nerves.Methods:The patients were divided into 2groups 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 1to 3years and the clinical outcome was compared between the two groups.

  7. LONG-TERM EVALUATION OF NERVE REGENERATION IN A BIODEGRADABLE NERVE GUIDE

    NARCIS (Netherlands)

    DENDUNNEN, WFA; VANDERLEI, B; SCHAKENRAAD, JM; BLAAUW, EH; STOKROOS, [No Value; PENNINGS, AJ; ROBINSON, PH

    1993-01-01

    Nerve regeneration using artificial biodegradable conduits is of increasing interest. The aim of this study is to evaluate the regeneration and maturation of a nerve after long-term implantation (2 years) of a biodegradable poly-L-lactide/poly-E-caprolactone (PLLA/PCL) copolymeric nerve guide in the

  8. 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.

  9. 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.

  10. Chondroitinase ABC improves recovery of long sciatic nerve defects

    Institute of Scientific and Technical Information of China (English)

    Hailong Yu; Liangbi Xiang; Wenjing Xu; Bin Zhao; Yu Wang; Jiang Peng; Shibi Lu

    2012-01-01

    Sciatic nerves from allogeneic Sprague-Dawley rats were pretreated with chondroitinase ABC and were used to bridge damaged sciatic nerves in Wistar rats. Chondroitin sulfate proteoglycans were removed from the chemically extracted acellular nerves. At 3 months after grafting, the footplate pinch test result was positive in the Wistar rats. Autotomy scores decreased, and increased muscular contraction tension appeared when triceps surae muscles were stimulated. In addition, the recovery rate of wet triceps surae muscle weight increased, and the distal segment of the chondroitinase ABC-treated graft exhibited Schwann cells next to the nerve fibers. These results suggested that chondroitinase ABC pretreatment enhanced repair of long nerve defects via acellular nerve grafting.

  11. Bone graft

    Science.gov (United States)

    ... around the area. The bone graft can be held in place with pins, plates, or screws. Why ... Orthopaedic Surgery, San Francosco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  12. 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

  13. 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.

  14. Engineered neural tissue with aligned, differentiated adipose-derived stem cells promotes peripheral nerve regeneration across a critical sized defect in rat sciatic nerve.

    Science.gov (United States)

    Georgiou, Melanie; Golding, Jon P; Loughlin, Alison J; Kingham, Paul J; Phillips, James B

    2015-01-01

    Adipose-derived stem cells were isolated from rats and differentiated to a Schwann cell-like phenotype in vitro. The differentiated cells (dADSCs) underwent self-alignment in a tethered type-1 collagen gel, followed by stabilisation to generate engineered neural tissue (EngNT-dADSC). The pro-regenerative phenotype of dADSCs was enhanced by this process, and the columns of aligned dADSCs in the aligned collagen matrix supported and guided neurite extension in vitro. EngNT-dADSC sheets were rolled to form peripheral nerve repair constructs that were implanted within NeuraWrap conduits to bridge a 15 mm gap in rat sciatic nerve. After 8 weeks regeneration was assessed using immunofluorescence imaging and transmission electron microscopy and compared to empty conduit and nerve graft controls. The proportion of axons detected in the distal stump was 3.5 fold greater in constructs containing EngNT-dADSC than empty tube controls. Our novel combination of technologies that can organise autologous therapeutic cells within an artificial tissue construct provides a promising new cellular biomaterial for peripheral nerve repair.

  15. 人工神经网络在晚期肝癌治疗计划系统中的应用%Therapy Plan System(TPS)with Artificial Nerve Network on Treatment of Advanced Liver Cancer

    Institute of Scientific and Technical Information of China (English)

    罗保平; 罗文新; 唐玉琼; 袁俊; 胡爱红; 尹红; 何敢想

    2013-01-01

    目的 将人工神经网络系统应用于晚期肝癌的治疗,建立临床实用的治疗计划系统,提高肝癌的治疗水平.方法 应用Visual C++6.0计算机语言,以临床症状、体征、诊断、辅助检查等重要的病理生理状态为类对象,建立数字人体,量化生理功能和药物效价,模拟生态系统,组建人工神经网络系统,用以代替医疗专家制定精确的治疗方案.结果 治疗计划系统提出的治疗方案准确无误,能精确控制化疗剂量,化疗副反应明显减少.结论 晚期肝癌治疗计划系统能较全面地模拟医疗专家的治疗思想,准确地提出治疗方案.%Objective Apply the artificial nerve network on the treatment of advanced liver cancer, establing TPS to improve the therapy of liver cancer . Methods With the Visual C+ +6. 0 calculator language, take the important pathophysiologi-cal state of clinical symptoms,signs,diagnosis,laboratory examinations as the object,and to quantify the physiological function of drug potency,imitate the ecological system,apply the artificial nerve network system instead of the accurate treatment plan from the medical expert . Results The rate of reliability for the group using TPS is as high as 100%. TPS can exactly control chemotherapy measure,and obviously reduce the vice-reaction of chemotherapy as well. Conclusion The treatment plan system of advanced liver cancer can comprehensiverly imitate the expert's thought,put forward an accurate plan on the treatment.

  16. Applied anatomy of the sciatic nerve injury in the artificial total hip arthroplasty%人工全髋关节置换术中坐骨神经损伤的应用解剖学观察

    Institute of Scientific and Technical Information of China (English)

    杨景武; 史晓林

    2005-01-01

    背景:人工全髋关节置换术(THR)是近年来治疗老年人髋关节疾患的首选方法,按Harri's评分优良率为84%.该手术对坐骨神经损伤发生率国内报道为0.46%,国外报道为0.08%~9.70%.目的:通过解剖位置的分析探讨THR术中坐骨神经损伤的因素.设计:以人体解剖标本为研究对象,单一样本研究.单位:湖州师范学院医学院解剖实验室.对象:实验于2003-03/05在湖州师范学院医学院解剖实验室完成.正常人体成年骨盆标本56具,男27具,女29具.方法:对坐骨神经的来源及走行、坐骨神经与髋臼的关系进行测量分析,并对在THR术中拉钩及螺丝钉固定所致坐骨神经损伤,进行详尽测量分析. 主要观察指标:坐骨神经与髋臼的位置关系.结果:测出坐骨神经至髋臼底的距离左侧为(6.00±0.85)mm,右侧为(6.00±0.71)mm;坐骨神经至髋臼缘的距离左侧为(13.00±0.75)mm,右侧为(14.00±0.06)mm.坐骨神经在髋臼缘处周径左侧为(32.00±0.28)mm,右侧为(31.00±0.68)mm.髋臼底至坐骨大孔的距离为左侧为(29.00±0.36)mm,右侧为(29.00±0.24)mm.结论:确定拉钩及螺丝钉固定在1~3点及5~6点为安全区.在THR术中陈旧髋臼骨折脱位、拉钩的位置不当、螺钉固定髋臼位置不当均可导致医源因素损伤坐骨神经.%BACKGROUND: At present, the artificial total hip replacement(THR) is the first choice of the hip joint disease for the old, and the choiceness rate is 84% according to the Harri' s grade, and the therapeutic effect is content. The occurrence rate of the sciatic nerve injury in the THR is reported to be 0.46% in and 0. 08%-9.7% abroad.OBJECTIVE: To study the influencing factors of the sciatic nerve injury in the THR through the anatomical location analysis.DESIGN: Single sample study based on the human anatomical samples.SETTING: Human Anatomy Laboratory in the Medical Department of the Huzhou Normal University.PARTICIPANTS: The study was completed in the

  17. Bilateral high radial nerve compressions: a case report.

    Science.gov (United States)

    Chuangsuwanich, A; Muangsombut, S; Sangruchi, T

    2000-06-01

    A 40-year-old woman with bilateral high radial nerve compressions by non-traumatic cause was reported. It occurred first at the right radial nerve which was explored after a period of investigation and conservative treatment. Two constricted sites 2.0 cm apart of the right radial nerve crossed by branches of the radial collateral artery beneath the lateral head of the triceps were found. The constricted sites including tissue in between was resected and replaced with a sural nerve graft. One year later the patient had the same episode on the left side. The operative finding was the same as the previous one. Sural nerve graft was performed after neurolysis had failed. The patient's normal radial nerve function returned in one year. This is the first reported case in the literature of bilateral high radial nerve compressions by branches of the radial collateral artery.

  18. 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

  19. Use of Natural Neural Scaffolds Consisting of Engineered Vascular Endothelial Growth Factor Immobilized on Ordered Collagen Fibers Filled in a Collagen Tube for Peripheral Nerve Regeneration in Rats

    Directory of Open Access Journals (Sweden)

    Fukai Ma

    2014-10-01

    Full Text Available The search for effective strategies for peripheral nerve regeneration has attracted much attention in recent years. In this study, ordered collagen fibers were used as intraluminal fibers after nerve injury in rats. Vascular endothelial growth factor (VEGF plays an important role in nerve regeneration, but its very fast initial burst of activity within a short time has largely limited its clinical use. For the stable binding of VEGF to ordered collagen fibers, we fused a collagen-binding domain (CBD to VEGF through recombinant DNA technology. Then, we filled the ordered collagen fibers-CBD-VEGF targeting delivery system in a collagen tube to construct natural neural scaffolds, which were then used to bridge transected nerve stumps in a rat sciatic nerve transection model. After transplantation, the natural neural scaffolds showed minimal foreign body reactions and good integration into the host tissue. Oriented collagen fibers in the collagen tube could guide regenerating axons in an oriented manner to the distal, degenerating nerve segment, maximizing the chance of target reinnervation. Functional and histological analyses indicated that the recovery of nerve function in the natural neural scaffolds-treated group was superior to the other grafted groups. The guiding of oriented axonal regeneration and effective delivery systems surmounting the otherwise rapid and short-lived diffusion of growth factors in body fluids are two important strategies in promoting peripheral nerve regeneration. The natural neural scaffolds described take advantage of these two aspects and may produce synergistic effects. These properties qualified the artificial nerve conduits as a putative candidate system for the fabrication of peripheral nerve reconstruction devices.

  20. Use of natural neural scaffolds consisting of engineered vascular endothelial growth factor immobilized on ordered collagen fibers filled in a collagen tube for peripheral nerve regeneration in rats.

    Science.gov (United States)

    Ma, Fukai; Xiao, Zhifeng; Meng, Danqing; Hou, Xianglin; Zhu, Jianhong; Dai, Jianwu; Xu, Ruxiang

    2014-10-15

    The search for effective strategies for peripheral nerve regeneration has attracted much attention in recent years. In this study, ordered collagen fibers were used as intraluminal fibers after nerve injury in rats. Vascular endothelial growth factor (VEGF) plays an important role in nerve regeneration, but its very fast initial burst of activity within a short time has largely limited its clinical use. For the stable binding of VEGF to ordered collagen fibers, we fused a collagen-binding domain (CBD) to VEGF through recombinant DNA technology. Then, we filled the ordered collagen fibers-CBD-VEGF targeting delivery system in a collagen tube to construct natural neural scaffolds, which were then used to bridge transected nerve stumps in a rat sciatic nerve transection model. After transplantation, the natural neural scaffolds showed minimal foreign body reactions and good integration into the host tissue. Oriented collagen fibers in the collagen tube could guide regenerating axons in an oriented manner to the distal, degenerating nerve segment, maximizing the chance of target reinnervation. Functional and histological analyses indicated that the recovery of nerve function in the natural neural scaffolds-treated group was superior to the other grafted groups. The guiding of oriented axonal regeneration and effective delivery systems surmounting the otherwise rapid and short-lived diffusion of growth factors in body fluids are two important strategies in promoting peripheral nerve regeneration. The natural neural scaffolds described take advantage of these two aspects and may produce synergistic effects. These properties qualified the artificial nerve conduits as a putative candidate system for the fabrication of peripheral nerve reconstruction devices.

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

    Institute of Scientific and Technical Information of China (English)

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

    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 macroscopi-cal y observed and histological y assessed. In the nanofibrous graft, the rat sciatic nerve trunk had been reconstructed by restoration of nerve continuity and formation of myelinated nerve fiber. There were Schwann cel s and glial cel s in the regenerated nerves. Masson’s trichrome staining showed that there were no pathological changes in the size and structure of gastrocnemius muscle cel s on the operated side of rats. These findings suggest that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit is suitable for repair of long-segment sciatic nerve defects.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Mohammadi Rahim

    2013-12-01

    Full Text Available 【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 phosphate-buffered saline. In sham-operated group the sciatic nerve was ex- posed 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 indi- ces confirmed a faster recovery of regenerated axons in VEGF group than in silicone group (P<0.05. In immunohistochemi- cal assessment, reactions to S-100 in VEGF group were more positive than that in silicone group. Conclusion: Local administration of VEGF will im- prove functional recovery and morphometric indices of sci- atic nerve. Key words: Peripheral nerves; Nerve regeneration; Sciatic nerve; Vascular endothelial growth factor

  4. VSD联合人工真皮复合自体刃厚皮移植在手足电击伤创面中的应用%Application of VSD combined with artificial dermis composite autologous split-thickness skin graft in electric injury of hands and feet

    Institute of Scientific and Technical Information of China (English)

    宋德恒; 刘继松; 李勇; 章祥洲; 余勇

    2016-01-01

    目的:观察应用负压封闭引流术( VSD)联合人工真皮复合自体刃厚皮移植修复手足电击伤创面的效果。方法:选取2011年1月-2014年12月应用VSD联合人工真皮支架复合自体刃厚皮片移植修复手足电击伤创面的病例,共11例创面,对创面先行扩创+VSD,10 d~3周创面基底肉芽发育良好后行人工真皮移植,2周后进行自体刃厚皮片移植。结果:11处电击伤创面移植皮片全部成活,皮片质地柔软形态饱满、弹性佳,手足关节功能满意,供皮区瘢痕不明显。结论:应用VSD联合人工真皮复合自体刃厚皮片移植修复手足电击伤创面能较好地保护患肢的形态和功能。%Objective:To observe application and effect of VSD combined with artificial dermis composite autologous split-thickness skin graft in the repair of electrically damaged wound of hands and feet.Methods:11cases of wounds of electrically damaged hands and feet were chosen which were treated with VSD combined with artificial dermis composite autologous split-thickness skin graft from Janu-ary 2011 to December 2014.Debridement of the wound was first conducted added with VSD.Artificial dermis transplantation was carried out after 10 days to 3 weeks when granulation tissues were well developed at the wound base.Autologous split-thickness skin grafting was given 2 weeks later.Results:All the 11cases of electrically damaged wounds survived after the surgery.The skin was soft in texture and good in elasticity.The joint function of hands and feet was satisfactory.Scar was not obvious.Conclusion:The application of VSD combined with artificial dermis composite antilogous split-thickness skin graft to repair electrically damaged wound of hands and feet can better protect the form and function of suffered limbs.

  5. Artificial human vision.

    Science.gov (United States)

    Dowling, Jason

    2005-01-01

    Can vision be restored to the blind? As early as 1929 it was discovered that stimulating the visual cortex of an individual led to the perception of spots of light, known as phosphenes [1] . The aim of artificial human vision systems is to attempt to utilize the perception of phosphenes to provide a useful substitute for normal vision. Currently, four locations for electrical stimulation are being investigated; behind the retina (subretinal), in front of the retina (epiretinal), the optic nerve and the visual cortex (using intra- and surface electrodes). This review discusses artificial human vision technology and requirements, and reviews the current development projects.

  6. 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.

  7. The role of exosomes in peripheral nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Rosanna C Ching; Paul J Kingham

    2015-01-01

    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 im-pregnated 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 dififculties and ethical concerns, and the use of autologous nerve grafts and Schwann cells requires the sacriifce 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.

  8. Operative considerations in implantation of the Perma-Flow graft.

    Science.gov (United States)

    Emery, R W; Joyce, L D; Arom, K V; King, R M; Nicoloff, D M

    1994-12-01

    The Perma-Flow coronary bypass graft (Possis Medical, Inc, Minneapolis, MN) currently is undergoing expanded clinical trial. From November 1992 through June 1994 we have used this artificial conduit in 8 patients without autologous alternatives. These cases allowed the establishment of a technical basis for successful implantation of this graft. All studied coronary anastomoses are patent.

  9. 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.

  10. 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

  11. Clinical implications of the surgical anatomy of the sural nerve.

    Science.gov (United States)

    Coert, J H; Dellon, A L

    1994-11-01

    The exact anatomy of the sural nerve remains important for many clinical situations. To better understand this anatomy, 25 embalmed and 10 fresh cadaver pairs were studied. The origin of the common sural nerve in relation to the fibular head and its medial and lateral sural components were investigated. The lateral sural nerve was absent in 4 percent of the embalmed cadavers. The lateral and medial sural nerves united in the popliteal fossa in 12 percent and in the lower third of the leg in 84 percent of the cadavers. A site was identified where the lateral sural and lateral cutaneous nerve of the calf pierced the deep fascia. This site was centered about the fibular head and may be viewed as a potential site of nerve compression. There is application of these findings to nerve grafting, neuroma prevention and treatment, and sural nerve biopsy.

  12. 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.

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

    Science.gov (United States)

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

    2010-02-09

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

  14. Effect of injecting brain cell growth peptide into conduit at the anastomose end of autogenous vein graft conduit on functional rehabilitation of facial nerve injury%自体静脉套吻合端套管内注入脑细胞生长肽对面神经损伤功能恢复的作用

    Institute of Scientific and Technical Information of China (English)

    韩思源; 宋涛; 王玉新

    2004-01-01

    背景:面神经损伤后功能恢复需要较长时间,如何加速面神经的功能恢复是该领域正在研究的课题.目的:比较面神经损伤修复的不同方法,探讨自体静脉套接吻合口及脑细胞生长肽在临床上修复面神经损伤的效果.设计:以诊断为依据的病例对照研究.地点和对象:中国医科大学附属第一医院1999-01/2001-12收治44例面神经损伤患者和1999-01以前收治面神经损伤患者30例.干预:对44例创伤后和腮腺区恶性肿瘤切除造成的面神经损伤患者,在手术显微镜下行神经断端对位吻合,将自体静脉管套入吻合口并在管套内注入脑细胞生长肽.对30例面神经损伤患者采用传统神经端吻合法修复,术后不同时间观察面部表情肌功能恢复及肌电图的动态变化.主要观察指标:观察面部表情肌功能恢复的时间,检测面神经传导速度的动态变化.结果:30例创伤性面神经损伤患者,功能恢复最快9周,最迟13周,平均(11.1±1.1)周,与传统方法(25.8±1.8)周比较有显著性差异(t=34.875,P<0.01);14例肿瘤切除面神经立即修复的患者,功能恢复最快13周,最迟15周,平均(13.8±0.8)周,与传统方法(34.8±2.9)周比较有显著性差异(t=26.336,P<0.01).肌电图检测面神经传导速度的恢复呈递增趋势,表情肌功能恢复时两种方法传导速度比较无显著性差异(P>0.05).结论:自体静脉管套入吻合口并注入脑细胞生长肽的方法均比传统方法效果显著,是一种临床效果比较突出的面神经损伤修复方法.%BACKGROUND: Functional rehabilitation requires longer time after facial nerve injury. How to speed up the functional rehabilitation of facial nerve is a topic in this academic field.OBJECTIVE: To discuss the effect of autogenous vein graft conduit anastomose and brain cell growth peptide(BCGP) on clinical rehabilitation of facial nerve injury by comparing different methods in the rehabilitation of facial

  15. 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

  16. 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.

  17. 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.

  18. Vascularized peripheral nerve trunk autografted in the spinal cord: a new experimental model in adult rats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To investigate the effect of vascularized peripheral nerve trunk autografted in spinal cord. Methods: With modern microsurgical technique,vascularized peripheral median and ulnar nerve trunk autografted in the upper thoracic region of the spinal cord were established in 20 female adult rats. The origin and the termination of axons in the graft were studied by retrograde neuronal labeling with horseradish peroxidase (HRP).Cord, nerve grafts and some normal median and ulnar nerves in the right upper limb were removed and sectioned for Bielschowsky's silver stain and haematoxylin and eosin (H&E) stain. Light and electron microscopic examination and electrophysiological examination were applied.Results: The grafts were innervated by many new fibers. Studies with HRP indicated that new axons in graft were originated from intrinsic central nervous system (CNS) neurons with their cell bodies from brain stem to sacral segments of spinal cord. Other axons arose from dorsal root ganglia at the level of graft and at least 19 distal segments to them. Together with electron microscopy, electrophysiological examination, silver and H&E stain, the results demonstrated that vascularized peripheral nerve trunk grafted in spinal cord attracted many neurons to grow into the nerve grafts.Conclusions: The findings implicate that CNS is able to regenerate much better in vascularized nerve autografted in spinal cord.

  19. Polyethylene glycol-grafted polystyrene particles.

    Science.gov (United States)

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

    2004-07-01

    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 characterized by determination of the PEG surface concentration, zeta-potential, size, and morphology. Under optimized grafting conditions, a dense "brush-like" PEG layer was formed. A PEG surface concentration of approximately 60 pmol/cm2, corresponding with an average distance between grafted PEG chains of approximately 17 A can be realized. It was shown that grafting of PEG onto PS-COOH reduced the adsorption of proteins from human plasma (85 vol %) in phosphate-buffered saline up to 90%.

  20. 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

  1. 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

  2. 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.

  3. 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 ...

  4. Vagus Nerve Stimulation

    Science.gov (United States)

    Vagus nerve stimulation Overview By Mayo Clinic Staff Vagus nerve stimulation is a procedure that involves implantation of a device that stimulates the vagus nerve with electrical impulses. There's one vagus nerve on ...

  5. Ulnar nerve dysfunction

    Science.gov (United States)

    Neuropathy - ulnar nerve; Ulnar nerve palsy; Mononeuropathy; Cubital tunnel syndrome ... neuropathy occurs when there is damage to the ulnar nerve. This ... syndrome may result. When damage destroys the nerve covering ( ...

  6. Nerve growth factor combined with an epineural conduit for bridging a short nerve gap (10 mm). A study in rabbits.

    Science.gov (United States)

    Barmpitsioti, Antonia; Konofaos, Petros; Ignatiadis, Ioannis; Papalois, Apostolos; Zoubos, Aristides B; Soucacos, Panagiotis N

    2011-10-01

    The purpose of this study was to evaluate the effect of direct administration of nerve growth factor (NGF) into an epineural conduit across a short nerve gap (10 mm) in a rabbit sciatic nerve model. The animals were divided into two groups. In group 1, n = 6, a 10-mm defect was created in the sciatic nerve and bridged with an epineural flap. A dose of 1 μg of NGF was locally administered daily for the first 21 days. NGF administration was made inside the epineural flap using a silicone reservoir connected to a silicone tube. In group 2, n = 6, the 10-mm defect was bridged with a nerve graft. This group did not receive any further treatment. At 13 weeks, all animals, before euthanasia, underwent electromyography (EMG) studies and then specimen sent for histology morphometric analysis. NGF administration ensured a significantly increased average number of myelinated axons per μm(2) (P = 0.028) and promoted fiber maturation (P = 0.031) and better EMG results (P = 0.046 for latency P = 0.048 for amplitude), compared with the control group. Although nerve grafts remain the gold standard for peripheral nerve repair, NGF-treated epineural conduits represent a good alternative, particularly when an unfavorable environment for nerve grafts is present.

  7. 人工真皮复合自体刃厚皮片修复关节处皮肤缺损创面的临床研究%Clinical study of artificial dermis combined with autologous thin skin graft for repairing soft tissue wounds at joints

    Institute of Scientific and Technical Information of China (English)

    俞泽浩; 肖亮; 邹崎葩; 贺光照

    2014-01-01

    目的:探讨人工真皮复合自体刃厚皮片对全身关节处皮肤缺损创面的疗效及愈后。方法收集2008~2013年采用人工真皮复合自体刃厚皮片修复关节处皮肤缺损创面25例,其中创面覆盖膝关节10例,踝关节5例,肘关节4例,腕关节2例,指关节间3例,腋窝部1例。观察其手术后皮片存活情况,术后3个月瘢痕形成程度及功能恢复情况。结果在采用人工真皮复合自体刃厚皮片治疗方法的患者中,18例患者一期术后通过换药及时清除脓性分泌物,类真皮样肉芽组织形成良好,3例患者人工真皮下出现感染,通过清洁换药,引流脓液后,类真皮样肉芽组织可再次形成。2例患者因感染较重,通过再次手术彻底清创并更换人工真皮,获得同样疗效,二期植皮术后,皮片均贴附良好。2例患者创面面积小,揭除人工真皮薄膜后,创面通过周围正常上皮爬行覆盖,自行愈合。术后3个月随访患者关节功能恢复良好,无明显瘢痕增生级瘢痕挛缩形成。结论人工真皮复合自体刃厚皮片疗法不仅能提高创面自体皮片移植成活率,并可有效降低关节处瘢痕挛缩程度,为患者的远期关节功能恢复,提供有效的治疗方案。%Objective To investigate the efficacy and prognosis of artificial dermis combined with autologous skin graft in the body joints dermal wounds.Methods Twenty-five cases were collected from 2008 to 2013,who used artificial dermis combined with autologous skin graft repair articular wounds,including 10 cases of wound knee,5 cases of the ankle,4 cases of the elbow,2 cases of the wrist,3 cases of the knuckles,1 case of the axillary.Skin graft survival after surgery,the extent and functional recovery of scar formation after 3 months were observed.Results Among the patients,who underwent artificial dermis combined with autologous skin graft repair operations,dermal tissue of 1 8 cases

  8. 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.

  9. Recent Strategies in Tissue Engineering for Guided Peripheral Nerve Regeneration.

    Science.gov (United States)

    Belanger, Kayla; Dinis, Tony M; Taourirt, Sami; Vidal, Guillaume; Kaplan, David L; Egles, Christopher

    2016-04-01

    The repair of large crushed or sectioned segments of peripheral nerves remains a challenge in regenerative medicine due to the complexity of the biological environment and the lack of proper biomaterials and architecture to foster reconstruction. Traditionally such reconstruction is only achieved by using fresh human tissue as a surrogate for the absence of the nerve. However, recent focus in the field has been on new polymer structures and specific biofunctionalization to achieve the goal of peripheral nerve regeneration by developing artificial nerve prostheses. This review presents various tested approaches as well their effectiveness for nerve regrowth and functional recovery.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. Artificial Intelligence.

    Science.gov (United States)

    Waltz, David L.

    1982-01-01

    Describes kinds of results achieved by computer programs in artificial intelligence. Topics discussed include heuristic searches, artificial intelligence/psychology, planning program, backward chaining, learning (focusing on Winograd's blocks to explore learning strategies), concept learning, constraint propagation, language understanding…

  15. 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

  16. Promising Technique for Facial Nerve Reconstruction in Extended Parotidectomy

    Directory of Open Access Journals (Sweden)

    Ithzel Maria Villarreal

    2015-11-01

    Full Text Available Introduction: Malignant tumors of the parotid gland account scarcely for 5% of all head and neck tumors. Most of these neoplasms have a high tendency for recurrence, local infiltration, perineural extension, and metastasis. Although uncommon, these malignant tumors require complex surgical treatment sometimes involving a total parotidectomy including a complete facial nerve resection. Severe functional and aesthetic facial defects are the result of a complete sacrifice or injury to isolated branches becoming an uncomfortable distress for patients and a major challenge for reconstructive surgeons.   Case Report: A case of a 54-year-old, systemically healthy male patient with a 4 month complaint of pain and swelling on the right side of the face is presented. The patient reported a rapid increase in the size of the lesion over the past 2 months. Imaging tests and histopathological analysis reported an adenoid cystic carcinoma. A complete parotidectomy was carried out with an intraoperative notice of facial nerve infiltration requiring a second intervention for nerve and defect reconstruction. A free ALT flap with vascularized nerve grafts was the surgical choice. A 6 month follow-up showed partial facial movement recovery and the facial defect mended.   Conclusion:  It is of critical importance to restore function to patients with facial nerve injury.  Vascularized nerve grafts, in many clinical and experimental studies, have shown to result in better nerve regeneration than conventional non-vascularized nerve grafts. Nevertheless, there are factors that may affect the degree, speed and regeneration rate regarding the free fasciocutaneous flap. In complex head and neck defects following a total parotidectomy, the extended free fasciocutaneous ALT (anterior-lateral thigh flap with a vascularized nerve graft is ideally suited for the reconstruction of the injured site.  Donor–site morbidity is low and additional surgical time is minimal

  17. Promising Technique for Facial Nerve Reconstruction in Extended Parotidectomy

    Science.gov (United States)

    Villarreal, Ithzel Maria; Rodríguez-Valiente, Antonio; Castelló, Jose Ramon; Górriz, Carmen; Montero, Oscar Alvarez; García-Berrocal, Jose Ramon

    2015-01-01

    Introduction: Malignant tumors of the parotid gland account scarcely for 5% of all head and neck tumors. Most of these neoplasms have a high tendency for recurrence, local infiltration, perineural extension, and metastasis. Although uncommon, these malignant tumors require complex surgical treatment sometimes involving a total parotidectomy including a complete facial nerve resection. Severe functional and aesthetic facial defects are the result of a complete sacrifice or injury to isolated branches becoming an uncomfortable distress for patients and a major challenge for reconstructive surgeons. Case Report: A case of a 54-year-old, systemically healthy male patient with a 4 month complaint of pain and swelling on the right side of the face is presented. The patient reported a rapid increase in the size of the lesion over the past 2 months. Imaging tests and histopathological analysis reported an adenoid cystic carcinoma. A complete parotidectomy was carried out with an intraoperative notice of facial nerve infiltration requiring a second intervention for nerve and defect reconstruction. A free ALT flap with vascularized nerve grafts was the surgical choice. A 6 month follow-up showed partial facial movement recovery and the facial defect mended. Conclusion: It is of critical importance to restore function to patients with facial nerve injury. Vascularized nerve grafts, in many clinical and experimental studies, have shown to result in better nerve regeneration than conventional non-vascularized nerve grafts. Nevertheless, there are factors that may affect the degree, speed and regeneration rate regarding the free fasciocutaneous flap. In complex head and neck defects following a total parotidectomy, the extended free fasciocutaneous ALT (anterior-lateral thigh) flap with a vascularized nerve graft is ideally suited for the reconstruction of the injured site. Donor–site morbidity is low and additional surgical time is minimal compared with the time of a single

  18. 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.

  19. 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.

  20. Posterior Interosseous Nerve Syndrome from Thermal Injury

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    Vijay A. Singh

    2014-01-01

    Full Text Available 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 posterior interosseous branch. However, problems can occur at the junction of the middle and proximal thirds of the humerus and wrist radially. When the radial nerve is injured by a burn, a new rehabilitation dynamic arises. Not only does one agonize about the return of nerve function but also fret about the skin grafts that replaced the devitalized tissue housing that compartment. Discussion. Although posterior interosseous nerve syndrome has been described in the context of many different etiologies, it has not previously been discussed in relation to burn injuries. In this case, not only did the patient’s rehabilitation involve aggressive therapy for return of sensation and function of the arm, but also prevention of contracture normally seen in replacement of full thickness burns.

  1. Multifunctional Silk Nerve Guides for Axon Outgrowth

    Science.gov (United States)

    Tupaj, Marie C.

    Peripheral nerve regeneration is a critical issue as 2.8% of trauma patients present with this type of injury, estimating a total of 200,000 nerve repair procedures yearly in the United States. While the peripheral nervous system exhibits slow regeneration, at a rate of 0.5 mm -- 9 mm/day following trauma, this regenerative ability is only possible under certain conditions. Clinical repairs have changed slightly in the last 30 years and standard methods of treatment include suturing damaged nerve ends, allografting, and autografting, with the autograft the gold standard of these approaches. Unfortunately, the use of autografts requires a second surgery and there is a shortage of nerves available for grafting. Allografts are a second option however allografts have lower success rates and are accompanied by the need of immunosuppressant drugs. Recently there has been a focus on developing nerve guides as an "off the shelf" approach. Although some natural and synthetic guidance channels have been approved by the FDA, these nerve guides are unfunctionalized and repair only short gaps, less than 3 cm in length. The goal of this project was to identify strategies for functionalizing peripheral nerve conduits for the outgrowth of neuron axons in vitro . To accomplish this, two strategies (bioelectrical and biophysical) were indentified for increasing axon outgrowth and promoting axon guidance. Bioelectrical strategies exploited electrical stimulation for increasing neurite outgrowth. Biophysical strategies tested a range of surface topographies for axon guidance. Novel methods were developed for integrating electrical and biophysical strategies into silk films in 2D. Finally, a functionalized nerve conduit system was developed that integrated all strategies for the purpose of attaching, elongating, and guiding nervous tissue in vitro. Future directions of this work include silk conduit translation into a rat sciatic nerve model in vivo for the purpose of repairing long

  2. 不同时段应用他克莫司纳米微球缓释颗粒促进同种异体神经移植再生的实验研究%Effects of controlled release of FK506 by P (DLLA-co-TMC) microspheres at different intervals on regeneration after allogenic nerve graft in a rodent model

    Institute of Scientific and Technical Information of China (English)

    柯于海; 张振伟; 冯登殿; 廖坚文; 李征; 庄加川

    2010-01-01

    目的 探讨不同时间段使用他克莫司(FK506)纳米微球在同种异体移植后促进神经的再生作用.方法 采用单乳化-溶剂挥发法(O/W)制备FK506纳米微球,同种异体移植大鼠胫神经.A组术后立即局部应用FK506纳米微球,B组24 h给药,C组3 d后给药,D组不给药;于术后第4、8和12周行移植神经大体观察、组织学检查及有髓纤维图像分析、小腿三头肌湿重测定、荧光素逆行标记神经元、双侧胫神经电生理比较.结果 FK506纳米微球降解快、吸收好.A、B组神经再生效果相似,都明显要比C、D组好,差异有统计学意义;C、D组之间差异也有统计学意义.结论 FK506纳米微球释药速度符合神经损伤后再生规律,局部应用有良好的促进神经再生作用,而且早期(24 h内)给药效果更加明显.%Objective To study the effect of the application of P(DLLA-co-TMC)/FK506 microspheres at different intervals on peripheral nerve regeneration after tibial nerve allograft. Methods P (DLLA-coTMC)/FK506 microspheres were fabricated using an oil-in-water single emulsion and solvent evaporation method.Tibial nerve allograft model was created in mice which were divided into group A, B, C and D. In groups A, B and C were P( DLLA-co-TMC)/FK506 microspheres were administered locally on the day of surgery, 24 hours postoperatively, and 3 days postoperatively, respectively. Group D was left untreated. On postoperative weeks 4,8 and 12, gross observation of the graft, histomorphometric image analysis, triceps surae wet weight,retrograde tracing and fluorescence microscopy of motor neurons, and electrophysiological examination of bilateral tibial nerves were carried out. Results P (DLLA-co-TMC)/FK506 microspheres degraded fast and were well absorbed. There was a statistically significant improvement in neuroregeneration in groups A and B comparing to that in groups C and D. There was also significant difference between groups C and D. Conclusion The

  3. Handcrafted multilayer PDMS microchannel scaffolds for peripheral nerve regeneration.

    Science.gov (United States)

    Hossain, Ridwan; Kim, Bongkyun; Pankratz, Rachel; Ajam, Ali; Park, Sungreol; Biswal, Sibani L; Choi, Yoonsu

    2015-12-01

    Injuries that result in the loss of limb functionality may be caused by the severing of the peripheral nerves within the affected limb. Several bioengineered peripheral nerve scaffolds have been developed in order to provide the physical support and topographical guidance necessary for the naturally disorganized axon outgrowth to reattach to distal nerve stumps as an alternative to other procedures, like nerve grafting. PDMS has been chosen for the base material of the scaffolds due to its biocompatibility, flexibility, transparency, and well-developed fabrication techniques. The process of observing the axon outgrowth across the nerve gaps with PDMS scaffolds has been challenging due to the limited number and fineness of longitudinal sections that can be extracted from harvested nerve tissue samples after implantation. To address this, multilayer microchannel scaffolds were developed with the object of providing more refined longitudinal observation of axon outgrowth by longitudinally 'sectioning' the device during fabrication, removing the need for much of the sample preparation process. This device was then implanted into the sciatic nerves of Lewis rats, and then harvested after two and four weeks to analyze the difference in nerve regeneration between two different time periods. The present layer by layer structure, which is separable after nerve regeneration and is treated as an individual layer during the histology process, provides the details of biological events during axonal regeneration. Confocal microscopic imaging showed the details of peripheral nerve regeneration including nerve branches and growth cones observable from within the microchannels of the multilayer PDMS microchannel scaffolds.

  4. 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.

  5. A biosynthetic nerve guide conduit based on silk/SWNT/fibronectin nanocomposite for peripheral nerve regeneration.

    Science.gov (United States)

    Mottaghitalab, Fatemeh; Farokhi, Mehdi; Zaminy, Arash; Kokabi, Mehrdad; Soleimani, Masoud; Mirahmadi, Fereshteh; Shokrgozar, Mohammad Ali; Sadeghizadeh, Majid

    2013-01-01

    As a contribution to the functionality of nerve guide conduits (NGCs) in nerve tissue engineering, here we report a conduit processing technique through introduction and evaluation of topographical, physical and chemical cues. Porous structure of NGCs based on freeze-dried silk/single walled carbon nanotubes (SF/SWNTs) has shown a uniform chemical and physical structure with suitable electrical conductivity. Moreover, fibronectin (FN) containing nanofibers within the structure of SF/SWNT conduits produced through electrospinning process have shown aligned fashion with appropriate porosity and diameter. Moreover, fibronectin remained its bioactivity and influenced the adhesion and growth of U373 cell lines. The conduits were then implanted to 10 mm left sciatic nerve defects in rats. The histological assessment has shown that nerve regeneration has taken places in proximal region of implanted nerve after 5 weeks following surgery. Furthermore, nerve conduction velocities (NCV) and more myelinated axons were observed in SF/SWNT and SF/SWNT/FN groups after 5 weeks post implantation, indicating a functional recovery for the injured nerves. With immunohistochemistry, the higher S-100 expression of Schwann cells in SF/SWNT/FN conduits in comparison to other groups was confirmed. In conclusion, an oriented conduit of biocompatible SF/SWNT/FN has been fabricated with acceptable structure that is particularly applicable in nerve grafts.

  6. A biosynthetic nerve guide conduit based on silk/SWNT/fibronectin nanocomposite for peripheral nerve regeneration.

    Directory of Open Access Journals (Sweden)

    Fatemeh Mottaghitalab

    Full Text Available As a contribution to the functionality of nerve guide conduits (NGCs in nerve tissue engineering, here we report a conduit processing technique through introduction and evaluation of topographical, physical and chemical cues. Porous structure of NGCs based on freeze-dried silk/single walled carbon nanotubes (SF/SWNTs has shown a uniform chemical and physical structure with suitable electrical conductivity. Moreover, fibronectin (FN containing nanofibers within the structure of SF/SWNT conduits produced through electrospinning process have shown aligned fashion with appropriate porosity and diameter. Moreover, fibronectin remained its bioactivity and influenced the adhesion and growth of U373 cell lines. The conduits were then implanted to 10 mm left sciatic nerve defects in rats. The histological assessment has shown that nerve regeneration has taken places in proximal region of implanted nerve after 5 weeks following surgery. Furthermore, nerve conduction velocities (NCV and more myelinated axons were observed in SF/SWNT and SF/SWNT/FN groups after 5 weeks post implantation, indicating a functional recovery for the injured nerves. With immunohistochemistry, the higher S-100 expression of Schwann cells in SF/SWNT/FN conduits in comparison to other groups was confirmed. In conclusion, an oriented conduit of biocompatible SF/SWNT/FN has been fabricated with acceptable structure that is particularly applicable in nerve grafts.

  7. Synergistic motor nerve fiber transfer between different nerves through the use of end-to-side coaptation.

    Science.gov (United States)

    Schmidhammer, R; Nógrádi, A; Szabó, A; Redl, H; Hausner, T; van der Nest, D G; Millesi, H

    2009-06-01

    End-to-end nerve repair is a widely used and successful experimental microsurgical technique via which a denervated nerve stump is supplied with reinnervating motor or sensory axons. On the other hand, questions are still raised as concerns the reliability and usefulness of the end-to-side coaptation technique. This study had the aim of the reinnervation of the denervated forearm flexor muscles in baboons through the use of an end-to-side coaptation technique and the synergistic action of the radial nerve. The median and ulnar nerves were transected, and the motor branch of the radial nerve supplying the extensor carpi radialis muscles (MBECR) was used as an axon donor for the denervated superficial forearm flexors. A nerve graft was connected to the axon donor nerve through end-to-side coaptation, while at the other end of the graft an end-to-end connection was established so as to reinnervate the motor branch of the forearm flexors. Electrophysiological investigations and functional tests indicated successful reinnervation of the forearm flexors and recovery of the flexor function. The axon counts in the nerve segments proximal (1038+/-172 S.E.M.) and distal (1050+/-116 S.E.M.) to the end-to-side coaptation site and in the nerve graft revealed that motor axon collaterals were given to the graft without the loss or appreciable misdirection of the axons in the MBECR nerve distal to the coaptation site. The nerve graft was found to contain varying, but satisfactory numbers of axons (269+/-59 S.E.M.) which induced morphological reinnervation of the end-plates in the flexor muscles. Accordingly, we have provided evidence that end-to-side coaptation can be a useful technique when no free donor nerve is available. This technique is able to induce limited, but still useful reinnervation for the flexor muscles, thereby producing a synergistic action of the flexor and extensor muscles which allows the hand to achieve a basic gripping function.

  8. Olecranon bone graft: revisited.

    Science.gov (United States)

    Mersa, Berkan; Ozcelik, Ismail Bulent; Kabakas, Fatih; Sacak, Bulent; Aydin, Atakan

    2010-09-01

    Autogenous bone grafts are frequently in use in the field of reconstructive upper extremity surgery. Cancellous bone grafts are applied to traumatic osseous defects, nonunions, defects after the resection of benign bone tumors, arthrodesis, and osteotomy procedures. Cancellous bone grafts do not only have benefits such as rapid revascularization, but they also have mechanical advantages. Despite the proximity to the primary surgical field, cancellous olecranon grafts have not gained the popularity they deserve in the field of reconstructive hand surgery. In this study, the properties, advantages, and technical details of harvesting cancellous olecranon grafts are discussed.

  9. An animal model of peripheral nerve regeneration after the application of a collagen-polyvinyl alcohol scaffold and mesenchymal stem cells.

    Science.gov (United States)

    Marinescu, Silviu Adrian; Zărnescu, Otilia; Mihai, Ioana Ruxandra; Giuglea, Carmen; Sinescu, Ruxandra Diana

    2014-01-01

    Extensive nerve injuries often leading to nerve gaps can benefit, besides the gold standard represented by autologous nerve grafts, by the inciting field of tissue engineering. To enhance the role of biomaterials in nerve regeneration, the nerve conduits are associated with Schwann or Schwann-like cells. In this study, we evaluated rat sciatic nerve regeneration, by using a biodegradable nerve guide composed of Collagen (COL) and Polyvinyl Alcohol (PVA), associated with mesenchymal stem cells (MSC). After the exposure of the rat sciatic nerve, a nerve gap was created by excising 1 cm of the nerve. Three experimental groups were used for nerve gap bridging: autografts, nerve conduits filled with medium culture and nerve conduits filled with MSC. The methods of sensory and motor assessment consisted of the functional evaluation of sciatic nerve recovery - toe-spread, pinprick tests and gastrocnemius muscle index (GMI). The histological and immunocytochemical analysis of the probes that were harvested from the repair site was performed at 12 weeks. Successful nerve regeneration was noted in all three groups at the end of the 12th week. The functional and immunocytochemical results suggested that COL-PVA tubes supported with mesenchymal stem cells could be considered similar to autologous nerve grafts in peripheral nerve regeneration, without the drawbacks of the last ones. The functional results were better for the autografts and the ultrastructural data were better for the nerve conduits, but there were not noticed any statistical differences.

  10. Artificial neural interfaces for bionic cardiovascular treatments.

    Science.gov (United States)

    Kawada, Toru; Sugimachi, Masaru

    2009-01-01

    An artificial nerve, in the broad sense, may be conceptualized as a physical and logical interface system that reestablishes the information traffic between the central nervous system and peripheral organs. Studies on artificial nerves targeting the autonomic nervous system are in progress to explore new treatment strategies for several cardiovascular diseases. In this article, we will review our research targeting the autonomic nervous system to treat cardiovascular diseases. First, we identified the rule for decoding native sympathetic nerve activity into a heart rate using transfer function analysis, and established a framework for a neurally regulated cardiac pacemaker. Second, we designed a bionic baroreflex system to restore the baroreflex buffering function using electrical stimulation of the celiac ganglion in a rat model of orthostatic hypotension. Third, based on the hypothesis that autonomic imbalance aggravates chronic heart failure, we implanted a neural interface into the right vagal nerve and demonstrated that intermittent vagal stimulation significantly improved the survival rate in rats with chronic heart failure following myocardial infarction. Although several practical problems need to be resolved, such as those relating to the development of electrodes feasible for long-term nerve activity recording, studies of artificial neural interfaces with the autonomic nervous system have great possibilities in the field of cardiovascular treatment. We expect further development of artificial neural interfaces as novel strategies to cope with cardiovascular diseases resistant to conventional therapeutics.

  11. Lateralization Technique and Inferior Alveolar Nerve Transposition

    Directory of Open Access Journals (Sweden)

    Angélica Castro Pimentel

    2016-01-01

    Full Text Available 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.

  12. 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

  13. Reconstruction of posterior interosseous nerve injury following biceps tendon repair: case report and cadaveric study.

    Science.gov (United States)

    Mokhtee, David B; Brown, Justin M; Mackinnon, Susan E; Tung, Thomas H

    2009-06-01

    Surgical repair of distal biceps tendon rupture is a technically challenging procedure that has the potential for devastating and permanently disabling complications. We report two cases of posterior interosseous nerve (PIN) injury following successful biceps tendon repair utilizing both the single-incision and two-incision approaches. We also describe our technique of posterior interosseous nerve repair using a medial antebrachial cutaneous nerve graft (MABC) and a new approach to the terminal branches of the posterior interosseous nerve that makes this reconstruction possible. Finally, we advocate consideration for identification of the posterior interosseous nerve prior to reattachment of the biceps tendon to the radial tuberosity.

  14. 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.

  15. Artificial blood.

    Science.gov (United States)

    Sarkar, Suman

    2008-07-01

    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.

  16. Recovery of Peripheral Nerve with Massive Loss Defect by Tissue Engineered Guiding Regenerative Gel

    Directory of Open Access Journals (Sweden)

    Shimon Rochkind

    2014-01-01

    Full Text Available Objective. Guiding Regeneration Gel (GRG was developed in response to the clinical need of improving treatment for peripheral nerve injuries and helping patients regenerate massive regional losses in peripheral nerves. The efficacy of GRG based on tissue engineering technology for the treatment of complete peripheral nerve injury with significant loss defect was investigated. Background. Many severe peripheral nerve injuries can only be treated through surgical reconstructive procedures. Such procedures are challenging, since functional recovery is slow and can be unsatisfactory. One of the most promising solutions already in clinical practice is synthetic nerve conduits connecting the ends of damaged nerve supporting nerve regeneration. However, this solution still does not enable recovery of massive nerve loss defect. The proposed technology is a biocompatible and biodegradable gel enhancing axonal growth and nerve regeneration. It is composed of a complex of substances comprising transparent, highly viscous gel resembling the extracellular matrix that is almost impermeable to liquids and gasses, flexible, elastic, malleable, and adaptable to various shapes and formats. Preclinical study on rat model of peripheral nerve injury showed that GRG enhanced nerve regeneration when placed in nerve conduits, enabling recovery of massive nerve loss, previously unbridgeable, and enabled nerve regeneration at least as good as with autologous nerve graft “gold standard” treatment.

  17. Skin grafting in severely contracted socket with the use of ′Compo′

    Directory of Open Access Journals (Sweden)

    Betharia S

    1990-01-01

    Full Text Available The results of split thickness autologous skin grafting along with the use of a dental impression material (Compo, a thermoplastic substance are presented in a series of 11 patients of acquired, severely contracted, anophthalmic sockets. Only the fornix fixation sutures and the central tarsorrhaphy were employed for the proper placement of graft without the use of retention devices. Artificial eyes were successfully fitted and retained subsequently after 6 weeks of grafting.

  18. Perioperative Period Treatments for Patients Underwent One-stage Coronary Artery bypass Grafting and Artificial Heart Valve Repair or Replacement%冠心病合并心脏瓣膜疾病同期手术治疗的围手术期处理要点

    Institute of Scientific and Technical Information of China (English)

    黎昱江; 刘学刚

    2013-01-01

    目的:探讨同期行冠脉旁路移植术和瓣膜置换或瓣膜成形术的围手术期的处理要点和注意事项,以期降低该类手术围手术期的死亡率.方法:通过Pubmed、万方数据库、中国知网等检索近几年国内外关于同期行冠脉旁路移植术和瓣膜置换或瓣膜成形术研究的相关文献,总结其围手术期的处理要点和注意事项.结果:同期行冠脉旁路移植术和瓣膜置换或瓣膜成形术,术前应注意患者各脏器功能情况,积极处理合并症;严格掌握手术适应证,制定合理的手术方式、手术流程;术中需掌握各种手术技巧,注意加强心肌保护;术后积极处理各种并发症.结论:同期行冠脉旁路移植术和瓣膜置换或瓣膜成形术,重视并掌握围手术期的处理要点和注意事项,在提高该类手术病人的生存率上起关键作用,能有效提高病人术后生存质量、降低其死亡率.%Objective:To investigate the perioperative period treatments for patients underwent one-stage coronary artery bypass grafting and artificial heart valve repair or replacement in order to reduce the surgical perioperative morbidity and mortality.Methods:To search the related literature in the database of PubMed,Wanfang Data and CNKI in recent years,to sum up the appropriate perioperative treatments.Results:In the perioperative period treatments for patients underwent one-stage coronary artery bypass grafting and artificial heart valve repair or replacement,it has many critical factors,including organs' condition before operation,correct assessment for operative indications,rational operative plan,operative skills,myocardial preservation in operation and prophylaxis and treatment for operation complications.Conclusions:The operation effect of patients underwent one-stage coronary artery bypass grafting and artificial heart valve repair or replacement will be increased remarkably if we pay attention to above-mentioned perioperative period

  19. Reconstruction of Posterior Interosseous Nerve Injury Following Biceps Tendon Repair: Case Report and Cadaveric Study

    OpenAIRE

    Mokhtee, David B.; Brown, Justin M.; Mackinnon, Susan E.; Tung, Thomas H.

    2008-01-01

    Surgical repair of distal biceps tendon rupture is a technically challenging procedure that has the potential for devastating and permanently disabling complications. We report two cases of posterior interosseous nerve (PIN) injury following successful biceps tendon repair utilizing both the single-incision and two-incision approaches. We also describe our technique of posterior interosseous nerve repair using a medial antebrachial cutaneous nerve graft (MABC) and a new approach to the termin...

  20. 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

  1. Immune Responses Following Mouse Peripheral Nerve Xenotransplantation in Rats

    Directory of Open Access Journals (Sweden)

    Lai-Jin Lu

    2009-01-01

    Full Text Available Xenotransplantation offers a potentially unlimited source for tissues and organs for transplantation, but the strong xenoimmune responses pose a major obstacle to its application in the clinic. In this study, we investigate the rejection of mouse peripheral nerve xenografts in rats. Severe intragraft mononuclear cell infiltration, graft distension, and necrosis were detected in the recipients as early as 2 weeks after mouse nerve xenotransplantation. The number of axons in xenografts reduced progressively and became almost undetectable at week 8. However, mouse nerve xenotransplantation only led to a transient and moderate increase in the production of Th1 cytokines, including IL-2, IFN-γ, and TNF-α. The data implicate that cellular immune responses play a critical role in nerve xenograft rejection but that further identification of the major effector cells mediating the rejection is required for developing effective means to prevent peripheral nerve xenograft rejection.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. Cross-chest median nerve transfer: a new model for the evaluation of nerve regeneration across a 40 mm gap in the rat.

    Science.gov (United States)

    Sinis, Nektarios; Schaller, Hans-Eberhard; Becker, Stephan Thomas; Lanaras, Tatjana; Schulte-Eversum, Caterina; Müller, Hans-Werner; Vonthein, Reinhard; Rösner, Harald; Haerle, Max

    2006-09-30

    A new animal model for the study of nerve regeneration in rats across a 40 mm gap between both median nerves is described. For autologous grafting, the ulnar nerves were dissected and sutured together. From the left median nerve, they were transplanted across the chest to the right median nerve. Animals having undergone this operation were observed for 12 months and periodically assessed using the grasping test and measurements of body-weight. For histological analysis rats were sacrificed after this period and axon counts were determined at the suture points of operated animals and in the median nerve of non-operated animals. Functional recovery could be seen, although partially, beginning as early as the fifth postoperative month, as demonstrated by the grasping test. Quantification of the number of axons demonstrated axonal regeneration across all three coaptation points. This model provides a new approach for analysis of long distance peripheral nerve regeneration without impairment of behaviour.

  7. 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

  8. 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...

  9. Artificial Limbs

    Science.gov (United States)

    ... diabetes. They may cause you to need an amputation. Traumatic injuries, including from traffic accidents and military combat Cancer Birth defects If you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which is ...

  10. 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....

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

    Institute of Scientific and Technical Information of China (English)

    Rodrigo Guerra Sabongi; Marcela Fernandes; Joo Baptista Gomes dos Santos

    2015-01-01

    Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the com-plexity 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 au-tologous 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.

  12. 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.

  13. 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.

  14. Laser Scanning In Vivo Confocal Microscopy of Clear Grafts after Penetrating Keratoplasty

    Science.gov (United States)

    Wang, Dai; Song, Peng; Wang, Shuting; Sun, Dapeng; Wang, Yuexin; Zhang, Yangyang

    2016-01-01

    Purpose. To evaluate the changes of keratocytes and dendritic cells in the central clear graft by laser scanning in vivo confocal microscopy after penetrating keratoplasty (PK). Methods. Thirty adult subjects receiving PK at Shandong Eye Institute and with clear grafts and no sign of immune rejection after surgery were recruited into this study, and 10 healthy adults were controls. The keratocytes and dendritic cells in the central graft were evaluated by laser scanning confocal microscopy, as well as epithelium cells, keratocytes, corneal endothelium cells, and corneal nerves (especially subepithelial plexus nerves). Results. Median density of subepithelial plexus nerves, keratocyte density in each layer of the stroma, and density of corneal endothelium cells were all lower in clear grafts than in controls. The dendritic cells of five (16.7%) patients were active in Bowman's membrane and stromal membrane of the graft after PK. Conclusions. Activated dendritic cells and Langerhans cells could be detected in some of the clear grafts, which indicated that the subclinical stress of immune reaction took part in the chronic injury of the clear graft after PK, even when there was no clinical rejection episode. PMID:27034940

  15. Laser Scanning In Vivo Confocal Microscopy of Clear Grafts after Penetrating Keratoplasty

    Directory of Open Access Journals (Sweden)

    Dai Wang

    2016-01-01

    Full Text Available Purpose. To evaluate the changes of keratocytes and dendritic cells in the central clear graft by laser scanning in vivo confocal microscopy after penetrating keratoplasty (PK. Methods. Thirty adult subjects receiving PK at Shandong Eye Institute and with clear grafts and no sign of immune rejection after surgery were recruited into this study, and 10 healthy adults were controls. The keratocytes and dendritic cells in the central graft were evaluated by laser scanning confocal microscopy, as well as epithelium cells, keratocytes, corneal endothelium cells, and corneal nerves (especially subepithelial plexus nerves. Results. Median density of subepithelial plexus nerves, keratocyte density in each layer of the stroma, and density of corneal endothelium cells were all lower in clear grafts than in controls. The dendritic cells of five (16.7% patients were active in Bowman’s membrane and stromal membrane of the graft after PK. Conclusions. Activated dendritic cells and Langerhans cells could be detected in some of the clear grafts, which indicated that the subclinical stress of immune reaction took part in the chronic injury of the clear graft after PK, even when there was no clinical rejection episode.

  16. Clinical Effect of Anterior Disc Excision with Bone Graft Fusion and Bryan Artificial Cervical Disc Replacement%颈前路减压植骨融合与Bryan人工颈椎间盘置换疗效比较

    Institute of Scientific and Technical Information of China (English)

    陈昆; 蔡惠民; 陈荣滋

    2014-01-01

    目的:探讨颈椎前路减压植骨融合术( anterior cervical decompression and fusion,ACDF)与Bryan人工颈椎椎间盘置换术( artificial cervical disc replacement,ACDR)两种手术方式用于治疗脊髓型颈椎病及神经根型颈椎病的近期和远期疗效。方法系统分析我院2010年11月至2012年11月70例(70个节段)脊髓型或神经根型颈椎病患者病例资料,将70例(70个节段)脊髓型或神经根型颈椎病患者,通过随机数字表法随机分为ACDF组(35例)及Bryan组(35例)。通过分析术前及术后随访12个月的Odom′s标准评分、活动度( range of motion,ROM)、日本骨科协会( Japa-nese orthopaedic association,JOA)、健康调查简表( the MOS item short from health survey,SF-36)及颈椎残障功能指数( neck disability index,NDI)观察指标的差异,同时对随访12个月的上述各项指标进行两组间比较,比较两者疗效,分析两种术式的优点及他们产生的问题。结果两种手术方式都能取得明确疗效,治疗后患者症状明显缓解( P0.05);JOA评分及SF-36评分两者差异性不显著( P>0.05);而在12个月随访ROM评估及NDI比较有差异,Bryan组数据优于 ACDF组,差异具有统计学意义( P0. 05). JOA score and SF-36 scale had no significant differences(P>0. 05). There was difference between ROM and NDI in the evaluation of 12 month follow-up. Data of Bryan group were better than ACDF group(P<0. 05). Conclusion Bryan artificial cervical disc re-placement(ACDR)is superior to the anterior cervical decompression and fusion(ACDF)in reducing the adjacent segment degeneration of cervical vertebra. Its short-term and mid-term curative effect is superior to the ACDF. But Bryan artificial cervi-cal disc replacement( ACDR)coexist the complications such as incomplete decompression and heterotopic ossification,the long-term curative effect is inferior than ACDF.

  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. Desorption electrospray ionization-based imaging of interaction between vascular graft and human body.

    Science.gov (United States)

    Bodzon-Kulakowska, Anna; Drabik, Anna; Mystkowska, Joanna; Chlabicz, Michal; Gacko, Marek; Dabrowski, Jan R; Mielczarek, Przemyslaw; Silberring, Jerzy; Suder, Piotr

    2016-01-01

    The desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) is known as a fast and convenient MS-based method for lipid imaging in various biological materials. Here, we applied this technique to visualize lipid distribution in a vascular graft removed from a patient's body. This is a good example of the DESI system capabilities toward imaging of interaction between artificial material and living tissues. Detailed analysis allowed for visualization of the spatial distribution of selected lipids in this implanted, artificial material. Not only DESI-MSI allowed visualization of lipid distribution in the investigated material but also enabled identification of the detected molecular species using MS/MS. Here, this technique was successfully used to evaluate the saturation and spatial distribution of endogenous lipids in the artificial vascular graft. Unambiguous identification of the lipids was done with the aid of fragmentation procedure. We also showed that various lipids localize preferably in graft material or internal plaque existing inside the graft.

  19. Iatrogenic facial nerve palsy "Prevention is better than cure": Analysis of four cases

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2011-01-01

    Full Text Available Iatrogenic facial nerve palsy in mastoid surgery is considered a crime or a taboo in the present scenario of medical science. But one has to accept the fact that every otologist encounters this entity at some point in his/her career. Hence it is of prime importance to be equipped to detect and to manage these cases. The obvious and disfiguring facial deformity it causes makes this a dreaded complication. Our article here discusses our experience in managing four cases of iatrogenic facial palsy. The etiology in all the cases was mastoidectomy for cholesteatoma. The detection of the site and repair was performed by the same surgeon in all cases. The facial nerve was transected completely in three cases, and in one case there was partial loss (>50% of fibers. Cable nerve grafting was utilized in three patients. There was grade 4 improvement in three patients who underwent cable nerve grafting, and one patient had grade 2 recovery after end-to-end anastomosis. A good anatomical knowledge and experience with temporal bone dissection is of great importance in preventing facial nerve injury. If facial nerve injury is detected, it should be managed as early as possible. An end-to-end anastomosis provides better results in final recovery as opposed to cable nerve grafting for facial nerve repair.

  20. Nerve conduction velocity

    Science.gov (United States)

    ... to measure the speed of the nerve signals. Electromyography (recording from needles placed into the muscles) is ... Often, the nerve conduction test is followed by electromyography (EMG). In this test, needles are placed into ...

  1. Common peroneal nerve dysfunction

    Science.gov (United States)

    ... toe-out movements Tests of nerve activity include: Electromyography (EMG, a test of electrical activity in muscles) Nerve ... Peroneal neuropathy. In: Preston DC, Shapiro BE, eds. Electromyography and Neuromuscular Disorders . 3rd ed. Philadelphia, PA: Elsevier; ...

  2. 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; Ming ZHANG; 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...

  3. Guided regeneration with resorbable conduits in experimental peripheral nerve injuries

    OpenAIRE

    Nicoli Aldini, N.; Fini, M; Rocca, M; Giavaresi, G.; Giardino, R.

    2000-01-01

    Guided tissue regeneration is a new approach in the reconstructive surgery of peripheral nerves. Artificial conduits can be constructed from biodegradable polymers. Lactic/caproic acid copolymers and polyphospazenes are biocompatible materials with a slow resorption rate. Conduits made from either poly-[l-lactide-co-6-caprolatone] or poly-[bis-(ethylalanate)-phosphazene] were assessed for use as guides for nerve regeneration in experimental animals. Under general anesthesia and by using a mic...

  4. 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

  5. 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......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...

  6. Repairing nerve gaps by vein conduits filled with lipoaspirate-derived entire adipose tissue hinders nerve regeneration.

    Science.gov (United States)

    Papalia, Igor; Raimondo, Stefania; Ronchi, Giulia; Magaudda, Ludovico; Giacobini-Robecchi, Maria G; Geuna, Stefano

    2013-05-01

    In spite of great recent advancements, the definition of the optimal strategy for bridging a nerve defect, especially across long gaps, still remains an open issue since the amount of autologous nerve graft material is limited while the outcome after alternative tubulization techniques is often unsatisfactory. The aim of this study was to investigate a new tubulization technique based on the employment of vein conduits filled with whole subcutaneous adipose tissue obtained by lipoaspiration. In adult rats, a 1cm-long defect of the left median nerve was repaired by adipose tissue-vein-combined conduits and compared with fresh skeletal muscle tissue-vein-combined conduits and autologous nerve grafts made by the excised nerve segment rotated by 180°. Throughout the postoperative period, functional recovery was assessed using the grasping test. Regenerated nerve samples were withdrawn at postoperative month-6 and processed for light and electron microscopy and stereology of regenerated nerve fibers. Results showed that functional recovery was significantly slower in the adipose tissue-enriched group in comparison to both control groups. Light and electron microscopy showed that a large amount of adipose tissue was still present inside the vein conduits at postoperative month-6. Stereology showed that all quantitative morphological predictors analyzed performed significantly worse in the adipose tissue-enriched group in comparison to the two control groups. On the basis of this experimental study in the rat, the use of whole adipose tissue for tissue engineering of peripheral nerves should be discouraged. Pre-treatment of adipose tissue aimed at isolating stromal vascular fraction and/or adipose derived stem/precursor cells should be considered a fundamental requisite for nerve repair.

  7. 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.

  8. Allograft pretreatment for the repair of sciatic nerve defects:green tea polyphenolsversus radiation

    Institute of Scientific and Technical Information of China (English)

    Sheng-hu Zhou; Ping Zhen; Shen-song Li; Xiao-yan Liang; Ming-xuan Gao; Qi Tian; Xu-sheng Li

    2015-01-01

    Pretreatment of nerve allografts by exposure to irradiation or green tea polyphenols can elimi-nate neuroimmunogenicity, inhibit early immunological rejection, encourage nerve regeneration and functional recovery, improve tissue preservation, and minimize postoperative infection. In the present study, we investigate which intervention achieves better results. We produced a 1.0 cm sciatic nerve defect in rats, and divided the rats into four treatment groups: autograft, fresh nerve allograft, green tea polyphenol-pretreated (1 mg/mL, 4°C) nerve allograft, and irradiation-pre-treated nerve allograft (26.39 Gy/min for 12 hours; total 19 kGy). The animals were observed, and sciatic nerve electrophysiology, histology, and transmission electron microscopy were carried out at 6 and 12 weeks after grafting. The circumference and structure of the transplanted nerve in rats that received autografts or green tea polyphenol-pretreated nerve allografts were similar to those of the host sciatic nerve. Compared with the groups that received fresh or irradiation-pre-treated nerve allografts, motor nerve conduction velocity in the autograft and fresh nerve allograft groups was greater, more neurites grew into the allografts, Schwann cell proliferation was evident, and a large number of new blood vessels was observed; in addition, massive myelinated nerve ifbers formed, and abundant microiflaments and microtubules were present in the axoplasm. Our ifndings indicate that nerve allografts pretreated by green tea polyphenols are equivalent to trans-planting autologous nerves in the repair of sciatic nerve defects, and promote nerve regeneration. Pretreatment using green tea polyphenols is better than pretreatment with irradiation.

  9. 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.

  10. Creating an Artificial Muscle

    Science.gov (United States)

    Bohon, Katherine; Krause, Sonja

    1997-03-01

    Striated skeletal muscle responds to a nerve impulse in less than 100 ms. In the past, polymeric gels and conducting polymers have been investigated for use as artificial muscle. However, the main problem with these materials is their relatively slow response (>3 seconds). On the other hand, electrorheological (ER) fluids are materials that change from a liquid to a solid upon application of an electric field. These fluids have a response on the order of a millisecond. A novel approach to artificial muscle utilizing the fast time response of ER fluids and the elasticity of polymeric gels has been investigated. A commercial sample of a two-part poly(dimethyl siloxane) (PDMS) dielectric gel was used. The PDMS was cured around two flexible electrodes 5 mm apart while a mixture of PDMS with solvent was cured between the electrodes. The solvents were either silicone oil or an ER fluid composed of crosslinked poly(ethylene oxide) (PEO) particles in silicone oil. The mixtures investigated were 90/10, 60/40, 50/50, 40/60, 10/90 PDMS/solvent. Upon application of a 6.2 kV/cm DC electric field the gel was reversibly compressed. The time response of the gel was actuator has been created using the 60/40 PDMS/ER fluid mixture.

  11. 人工耳蜗植入中的相关解剖与面神经功能保护%Morphologic study of the adjacent structures in artificial cochlea implantation and their correlation with facial nerve

    Institute of Scientific and Technical Information of China (English)

    何利平; 贺飞; 李永新; 赵啸天

    2004-01-01

    AIM: To define anatomical relationships important in cochlear implantation with morphometry of the adjacent structures so as to provide theoretical foundation for extended clinical application.METHODS: Microanatomical study was carried out on 40 adult temporal bones with operation microscope to measure the height of pyramidal eminence (PE) and facial nerve canal(FNC), and the depth of facial recess(FR) and tympanic sinus(TS).RESULTS: The height of PE and FNC were(2. 2 +0.07) mm and(2.2 +0.07) mm, and the depth of FR and TS were(1.8 +0.09) mm and (2.9 +0. 11 ) mm respectively. Statistical analysis has proved the correlation of PE with FR( R = 0. 55, t = 3.82), which is of significance( P < 0.01 ).CONCLUSION: PE was an important anatomical landmark not only with respect to posterior tympanic, but also to the second genu of facial nerve (FN), styloid complex, four recesses and five bone ridges, whose height has positive relation with the depth of FR. The results obtained in this study supplement our knowledge of the anatomy of the middle ear, which was of great importance in avoiding possible trauma of facial nerve and other adjacent structure during operation.%目的:对人工耳蜗植入手术相关的部分解剖结构进行观察、测量,找出与手术相关的因素,为临床开展人工耳蜗植入手术提供理论参考.方法:取成人颞骨40侧(左:23,右:17),在手术显微镜下观察、测量了锥隆起及面神经管的高度、面隐窝和鼓室窦的深度.结果:锥隆起的高度为(2.2±0.07)mm,面神经骨管的高度为(3.8±0.1)mm,面隐窝的深度为(1.8±0.09)mm,鼓室窦的深度为(2.9±0.11)mm,统计学表明锥隆起与面隐窝有相关性(R=0.55,t=3.82),因此两者有显著性意义(P<0.01).结论:锥隆起不仅为后鼓室的重要解剖标志,也为面神经第2膝、茎突复合体、4个隐窝和5个骨嵴的解剖标志,并且锥隆起越高面隐窝相应的越深.文中数据为中耳手术提供了更多的参考数

  12. Polymer scaffolds with preferential parallel grooves enhance nerve regeneration.

    Science.gov (United States)

    Mobasseri, Atefeh; Faroni, Alessandro; Minogue, Ben M; Downes, Sandra; Terenghi, Giorgio; Reid, Adam J

    2015-03-01

    We have modified the surface topography of poly ɛ-caprolactone (PCL) and polylactic acid (PLA) blended films to improve cell proliferation and to guide the regeneration of peripheral nerves. Films with differing shaped grooves were made using patterned silicon templates, sloped walls (SL), V-shaped (V), and square-shaped (SQ), and compared with nongrooved surfaces with micropits. The solvent cast films were tested in vitro using adult adipose-derived stem cells differentiated to Schwann cell-like cells. Cell attachment, proliferation, and cell orientation were all improved on the grooved surfaces, with SL grooves giving the best results. We present in vivo data on Sprague-Dawley rat sciatic nerve injury with a 10-mm gap, evaluating nerve regeneration at 3 weeks across a polymer nerve conduit modified with intraluminal grooves (SL, V, and SQ) and differing wall thicknesses (70, 100, 120, and 210 μm). The SL-grooved nerve conduit showed a significant improvement over the other topographical-shaped grooves, while increasing the conduit wall thickness saw no positive effect on the biological response of the regenerating nerve. Furthermore, the preferred SL-grooved conduit (C) with 70 μm wall thickness was compared with the current clinical gold standard of autologous nerve graft (Ag) in the rat 10-mm sciatic nerve gap model. At 3 weeks postsurgery, all nerve gaps across both groups were bridged with regenerated nerve fibers. At 16 weeks, features of regenerated axons were comparable between the autograft (Ag) and conduit (C) groups. End organ assessments of muscle weight, electromyography, and skin reinnervation were also similar between the groups. The comparable experimental outcome between conduit and autograft, suggests that the PCL/PLA conduit with inner lumen microstructured grooves could be used as a potential alternative treatment for peripheral nerve repair.

  13. Optic nerve oxygenation

    DEFF Research Database (Denmark)

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

    2005-01-01

    -oxygenase inhibitor, indomethacin, which indicates that prostaglandin metabolism plays a role. Laboratory studies suggest that carbonic anhydrase inhibitors might be useful for medical treatment of optic nerve and retinal ischemia, potentially in diseases such as glaucoma and diabetic retinopathy. However, clinical...... 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...... 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...

  14. Optic nerve oxygenation

    DEFF Research Database (Denmark)

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

    2005-01-01

    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...... 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......-oxygenase inhibitor, indomethacin, which indicates that prostaglandin metabolism plays a role. Laboratory studies suggest that carbonic anhydrase inhibitors might be useful for medical treatment of optic nerve and retinal ischemia, potentially in diseases such as glaucoma and diabetic retinopathy. However, clinical...

  15. Artificial ribonucleases.

    Science.gov (United States)

    Morrow, J R

    1994-01-01

    Many inorganic and organic compounds promote the reactions catalyzed by RNase A. Both the transesterification step, where a 2',3'-cyclic phosphate is formed with concomitant cleavage of RNA, and the hydrolysis step, where the 2',3'-cyclic phosphate is converted to a phosphate monoester, may be mimicked with compounds that are readily synthesized in the laboratory. Electrophilic activation of the phosphate ester and charge neutralization are generally important means by which artificial RNases promote phosphate diester displacement reactions. Several artificial RNases operate by a bifunctional general acid/general base mechanism, as does RNase A. Provision of an intramolecular nucleophile appears to be an important pathway for metal complex promoted phosphate diester hydrolysis. In contrast to the successful design of compounds that promote the reactions catalyzed by RNase A, there are no artificial nucleases to date that will cleave the 3' P-O bond of RNA or hydrolyze an oligonucleotide of DNA. Artificial RNases based on both metal complexes and organic compounds have been described. Metal complexes may be particularly effective catalysts for both transesterification and hydrolysis reactions of phosphate diesters. Under physiological conditions (37 degrees C and neutral pH), several metal complexes catalyze the transesterification of RNA. Future work should involve the development of metal complexes which are inert to metal ion release but which maintain open coordination sites for catalytic activity. The design of compounds containing multiple amine or imidazole groups that may demonstrate bifunctional catalysis is a promising route to new artificial RNases. Further design of these compounds and careful placement of catalytic groups may yield new RNase mimics that operate under physiological conditions. The attachment of artificial RNases to recognition agents such as oligodeoxynucleotides to create new sequence-specific endoribonucleases is an exciting field of

  16. [Microneural reconstruction after iatrogenic lesions of the lingual nerve and the inferior alveolar nerve. Critical evaluation].

    Science.gov (United States)

    Cornelius, C P; Roser, M; Ehrenfeld, M

    1997-07-01

    As microneural repair techniques of the sensory mandibular branches enter the third decade of their clinical use, there are but a few long-term investigations into the value of these procedures in the treatment of iatrogenic injury to the lingual (LN), inferior alveolar (IAN) or mental (MN) nerve. To establish the efficacy of microneural repair in lesions of the LN, IAN or MN with loss of continuity, the outcome of sensory recovery was evaluated in a series of 92 patients (LN: direct coaptation n = 39, coaptation + sural nerve grafting n = 23; IAN: direct coaptation n = 11 coaptation + sural nerve grafting n = 10; MN: direct coaptation n = 11). The minimum duration of follow-up was 14 months postoperatively. The persistent sensory deficit was assessed using standardized neurosensory testing and gustometric stimuli. In addition the patients answered a multiple-choice questionnaire containing a list of complaints. To obtain a numeric estimate for interindividual and intergroup comparison the information from clinical measurements and patient reports was condensed into a 'neurological score' and a 'complaint score', respectively. Furthermore, adequate items from both scores were combined to affirm or deny the return of sensory function in terms of protective and discriminative sensation. The overall results show a broad range of variation in the scores, sometimes reflecting severe degrees of persistent sensory impairment. The lowest scores, corresponding to the best regeneration, were found after direct coaptation of the LN, IAN and NM, but even the best results did not provide sensory recovery to a preinjury level. After direct coaptation of LN 69% of the patients exhibited protective sensation and 41% regained discriminative function. In contrast, LN grafting was ensued from restoration of protective function in 39% and discriminative function in 17% of the patients. More striking differences were found between coaptation and grafting of the IAN (IAN coaptation: 91

  17. 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.

  18. An anatomic study of vascularized fibular grafts

    Institute of Scientific and Technical Information of China (English)

    ZHU Yue-liang; XU Yong-qing; YANG Jun; Li Jun; LAN Xiu-fu

    2008-01-01

    Objective: To study the applied anatomy of the vascular and muscular innervations related to vascularized fibular grafts.Methods: Thirty-four cadaveric lower extremities were dissected for this study.The observations included fibular length,fibular nutrient artery,arcuate arteries,and innervation of fibular muscles.The fibulas were averagely divided into four segments and the locations of relevant vessels and nerves were ascertained.Results: All specimens had 1 fibular nutrient artery and 4-9 arcuate arteries except 1 specimen which had only 1 arcuate artery.The fibular nutrient artery and the first threearcuate arteries were constantly located between the distal half of the 1/4 segment and 2/4 segment of the fibula.The muscular branch of the superficial peroneal nerve passed through the surface of the periosteum in the 2/4 segment of the fibula.Conclusions: The most proximal osteotomy point locates at the midpoint of the 1/4 segment by which it ensure the maximal potential for preserving the nutrient vessels.The muscular branch of the superficial peroneal nerve is fragile to injury at the 2/4 segment of the fibula.

  19. Artificial blood.

    OpenAIRE

    1983-01-01

    #Blood substitutes have been developed for almost a century. The various type of artificial blood was continuously available on the market. The theme of this report is to identify the best substitute in emergency situation for some patients and science students. The definition of best is given; thus, as the vital part of the report, the comparison between them is described and discussed. Modified hemoglobin, bovine-based hemoglobin and PFCs are three basic types. In terms of the perfor...

  20. 髂外-腘动脉人工血管交叉转流术治疗髂股动脉硬化闭塞症%External iliac-popliteal artery artificial graft cross bypass for the treatment of arterial occlusion in lilac-femoral arteriosclerosis

    Institute of Scientific and Technical Information of China (English)

    马杰; 马韬

    2009-01-01

    Objective To study the curative effectiveness of external iliac-popliteal artery artificial graft cross bypass in treating extensive arterial occlusion in unilateral lilac-femoral arteriosclerosis. Methods From Sep. 1999 to Oct. 2007, 39 elder patients were diagnosed as having extensive arterial occlusion in unilateral lilac-femoral arteriosclerosis by color Doppler ultrasonography, CTA or DSA. 25 patients (61.5%) had resting pain, 14 had ulcers or gangrenes in the toes. The average ankle-brachial index was 0. 19. Contralateral external iliac-popliteal artery artificial graft cross bypass surgeries were performed on 22 patients from left to right, the other 17 were from right to left. Results There were no perioperative death or amputation. The ankle-brachial index increased from 0 ~ 0. 41 ( preoperative ) to 0. 85 ~ 1.02(postoperative) ; the claudication distance increased from 15 ~ 60 m (preoperative) to 350 ~ 500 m or more than 500 m [ postoperatively at the speed of (100 ~ 120) m/min] ; The postoperative color Doppler uhrasonography showed the average velocity of the popliteal artery was 45 cm/s. In the anterior tibial artery or the posterior tibial artery, little blood flow was showed in preoperative color Doppler ultrasonography examination, the postoperative average blood flow velocity was 41 cm/s. 35 patients (89. 7% ) were followed up for an average of 3.4 years, with an accumulative patency rate of 85.7%. Four patients had amputation, the limb salvage rate is 88.6%. Conclusion External iliac-popliteal artery artificial graft cross bypass is effective in treating unilateral lilac-femoral arterial occlusion, particularly for aged patients with vital organ incompetence.%目的 探讨髂外动脉-腘动脉人工血管移植交义转流术治疗单侧髂股动脉硬化广泛性闭塞的疗效.方法 1999年9月至2007年10月39例患者经血管彩超、CT血管造影(CTA)或数字减影血管造影(DSA)检查,证实单侧髂股动脉

  1. Artificial vision.

    Science.gov (United States)

    Zarbin, M; Montemagno, C; Leary, J; Ritch, R

    2011-09-01

    A number treatment options are emerging for patients with retinal degenerative disease, including gene therapy, trophic factor therapy, visual cycle inhibitors (e.g., for patients with Stargardt disease and allied conditions), and cell transplantation. A radically different approach, which will augment but not replace these options, is termed neural prosthetics ("artificial vision"). Although rewiring of inner retinal circuits and inner retinal neuronal degeneration occur in association with photoreceptor degeneration in retinitis pigmentosa (RP), it is possible to create visually useful percepts by stimulating retinal ganglion cells electrically. This fact has lead to the development of techniques to induce photosensitivity in cells that are not light sensitive normally as well as to the development of the bionic retina. Advances in artificial vision continue at a robust pace. These advances are based on the use of molecular engineering and nanotechnology to render cells light-sensitive, to target ion channels to the appropriate cell type (e.g., bipolar cell) and/or cell region (e.g., dendritic tree vs. soma), and on sophisticated image processing algorithms that take advantage of our knowledge of signal processing in the retina. Combined with advances in gene therapy, pathway-based therapy, and cell-based therapy, "artificial vision" technologies create a powerful armamentarium with which ophthalmologists will be able to treat blindness in patients who have a variety of degenerative retinal diseases.

  2. Propagation and spatiotemporal summation of electrical pulses in semiconductor nerve fibers

    Science.gov (United States)

    Samardak, A.; Taylor, S.; Nogaret, A.; Hollier, G.; Austin, J.; Ritchie, D. A.

    2007-08-01

    The authors report the propagation and analog summation of electrical impulses in artificial nerve fibers made of submicron p-n wires. These wires model the longitudinal conductivities of K + and Na+ ions inside and outside a nerve capillary as well as the transverse capacitance of the nerve membrane and the nonlinear conductance of its ion channels. They demonstrate the summation and annihilation of electrical impulses at room temperature which form the basis for making spike timing neural networks.

  3. Modulation of brain dead induced inflammation by vagus nerve stimulation.

    Science.gov (United States)

    Hoeger, S; Bergstraesser, C; Selhorst, J; Fontana, J; Birck, R; Waldherr, R; Beck, G; Sticht, C; Seelen, M A; van Son, W J; Leuvenink, H; Ploeg, R; Schnuelle, P; Yard, B A

    2010-03-01

    Because the vagus nerve is implicated in control of inflammation, we investigated if brain death (BD) causes impairment of the parasympathetic nervous system, thereby contributing to inflammation. BD was induced in rats. Anaesthetised ventilated rats (NBD) served as control. Heart rate variability (HRV) was assessed by ECG. The vagus nerve was electrically stimulated (BD + STIM) during BD. Intestine, kidney, heart and liver were recovered after 6 hours. Affymetrix chip-analysis was performed on intestinal RNA. Quantitative PCR was performed on all organs. Serum was collected to assess TNFalpha concentrations. Renal transplantations were performed to address the influence of vagus nerve stimulation on graft outcome. HRV was significantly lower in BD animals. Vagus nerve stimulation inhibited the increase in serum TNFalpha concentrations and resulted in down-regulation of a multiplicity of pro-inflammatory genes in intestinal tissue. In renal tissue vagal stimulation significantly decreased the expression of E-selectin, IL1beta and ITGA6. Renal function was significantly better in recipients that received a graft from a BD + STIM donor. Our study demonstrates impairment of the parasympathetic nervous system during BD and inhibition of serum TNFalpha through vagal stimulation. Vagus nerve stimulation variably affected gene expression in donor organs and improved renal function in recipients.

  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. 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.

  6. 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.).

  7. 周围神经损伤修复及功能恢复评价%Peripheral nerve injury repair and functional recovery

    Institute of Scientific and Technical Information of China (English)

    吕荣

    2011-01-01

    OBJECTIVE: To evaluate the properties, application and evaluation method of functional recovery in the repair of peripheral nerve defects using various biological artificial materials, and to search a suitable alternative to peripheral nerves.METHODS: Using "nerve conduit, peripheral nerve repair, biomaterials, Schwann cells" in Chinese as key words, a computer retrieval for articles from January 2004 to November 2010 was performed. Literatures about tissue engineering nerve and biomaterials were included; repeat study or Meta analysis articles were excluded. A total of 59 papers mainly focus the type,performance, and appropriate evaluation method of functional recovery of biological artificial materials on the restoration of peripheral nerve.RESULTS : The acellular nerve matrix and the composite biological engineered materials based on synthetic degradable materials as the main body, can be used as ideal scaffold materials for peripheral nerve tissue engineering. Acellular nerve scaffolds solve limited source of autologous nerve, graft rejection and other problems, its toughness and plasticity are close to autologous nerve, its micro-environment is more conducive to peripheral nerve regeneration. Synthetic biodegradable materials have biodegradability, plasticity, permeability and other advantages, and the commercialized products have emerged. If such materials were used to structure the complex materials, it is likely possible to obtain tissue engineered nerve graft with good performance. Functional recovery after peripheral nerve repair is mainly assessed by general and morphology, histological observations, neuromuscular fu nction assessment, as well as molecular biology techniques. The application of various evaluation methods is conducive to screen out the repair materials and construction programs of peripheral nerve injury.CONCLUSION: The biological artificial materials in the restoration of peripheral nerve injury are rapidly developing, but still need a

  8. [Chickenpox, burns and grafts].

    Science.gov (United States)

    Rojas Zegers, J; Fidel Avendaño, L

    1979-01-01

    An outbreak of chickenpox that occurred at the Burns Repair Surgery Unit, Department of Children's Surgery, Hospital R. del Río, between June and November, 1975, is reported. 27 cases of burned children were studied, including analysis of correlations of the stages and outcome of the disease (varicela), the trauma (burns) and the graft (repair surgery). As a result, the authors emphasize the following findings: 1. Burns and their repair are not aggravating factors for varicella. In a small number of cases the exanthema looked more confluent in the graft surgical areas and in the first degree burns healing spontaneously. 2. Usually there was an uneventful outcome of graft repair surgery on a varicella patient, either during the incubation period, the acme or the convalescence. 3. The fact that the outmost intensity of secondary viremia of varicella occurs before the onset of exanthemia, that is, during the late incubation period, is confirmed.

  9. Alveolar bone grafting

    Directory of Open Access Journals (Sweden)

    Lilja Jan

    2009-10-01

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

  10. End-to-side neurorrhaphy as a salvage procedure for irreparable nerve injuries. Technical note.

    Science.gov (United States)

    Oğün, Tunç C; Ozdemir, Mustafa; Senaran, Hakan; Ustün, Mehmet E

    2003-07-01

    After a few reports on end-to-side nerve repair at the beginning of the last century, the technique was put aside until its recent reintroduction. The authors present their results in three patients with median nerve defects that were between 15 and 22 cm long and treated using end-to-side median-to-ulnar neurorrhaphy through an epineurial window. The follow-up times were between 32 and 38 months. Sensory evaluation involved superficial touch, pinprick, and two-point discrimination tests. Motor evaluation was completed by assessing the presence of opposition and by palpating the abductor pollicis brevis muscle. Sensory recovery was observed in all patients in the median nerve dermatome, and motor recovery was absent, except in Case 1. End-to-side nerve repair can be a viable alternative to nerve grafting in patients with long gaps between the ends of the injured nerve.

  11. 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.

  12. Long-term survival and integration of transplanted engineered nervous tissue constructs promotes peripheral nerve regeneration.

    Science.gov (United States)

    Huang, Jason H; Cullen, D Kacy; Browne, Kevin D; Groff, Robert; Zhang, Jun; Pfister, Bryan J; Zager, Eric L; Smith, Douglas H

    2009-07-01

    Although peripheral nerve injury is a common consequence of trauma or surgery, there are insufficient means for repair. In particular, there is a critical need for improved methods to facilitate regeneration of axons across major nerve lesions. Here, we engineered transplantable living nervous tissue constructs to provide a labeled pathway to guide host axonal regeneration. These constructs consisted of stretch-grown, longitudinally aligned living axonal tracts inserted into poly(glycolic acid) tubes. The constructs (allogenic) were transplanted to bridge an excised segment of sciatic nerve in the rat, and histological analyses were performed at 6 and 16 weeks posttransplantation to determine graft survival, integration, and host regeneration. At both time points, the transplanted constructs were found to have maintained their pretransplant geometry, with surviving clusters of graft neuronal somata at the extremities of the constructs spanned by tracts of axons. Throughout the transplanted region, there was an intertwining plexus of host and graft axons, suggesting that the transplanted axons mediated host axonal regeneration across the lesion. By 16 weeks posttransplant, extensive myelination of axons was observed throughout the transplant region. Further, graft neurons had extended axons beyond the margins of the transplanted region, penetrating into the host nerve. Notably, this survival and integration of the allogenic constructs occurred in the absence of immunosuppression therapy. These findings demonstrate the promise of living tissue-engineered axonal constructs to bridge major nerve lesions and promote host regeneration, potentially by providing axon-mediated axonal outgrowth and guidance.

  13. Joint Probability Algorithm in Data Association Based on DHN Artificial Nerve Network%多目标跟踪中联合概率数据关联优化算法

    Institute of Scientific and Technical Information of China (English)

    廖辉荣; 李国林

    2011-01-01

    In the complex electromagnetic environment with dense target concentration, the classic joint probability data association algorithm in multi-target tracking is associated with the enormous amount of computing. The realtime ability and associating effectiveness of algorithm cannot meet the requirements base on present hardware. The conditions of constraints for optimizing are defined by quantizing the statistical distance of targets with measurement in the feasible joint event, thus constructing an energy function and translating the problem of searching the best feasible matrix into an integer planning optimization problem. On the basis of analyzing the completeness of optimality conditions, the preferred joint probability data association algorithm is invented by constructing DHN artificial neural network and using the nonlinear computing ability. And the method of disturbance controlled by system temperature is a-dopted to improve the convergence rate and reduce the amount of computing. The simulation results indicate that the algorithm can distribute the measured data to target-path effectively in real-time.%研究多目标实时精确跟踪问题,针对在战场目标密集和电磁环境复杂的情况下,经典多目标跟踪联合概率数据关联算法的计算量剧增,在目前的硬件条件下,算法的实时性和有效性已不能满足要求.为提高算法的计算速度和效率,通过量化可行联合事件中相匹配的量测与目标的统计距离,来定义优化计算的约束条件,从而构建能量函数,把搜索最优可行矩阵问题转化为整数规划问题,对算法进行改进.在分析优化条件完备性的基础上,构建DHN人工神经网络,利用非线性计算能力对整数规划问题进行求解,并采用温控扰动的办法提高收敛速度,降低计算量.仿真结果表明,算法能在复杂条件下实时有效地量测数据,准确分配给目标航迹.

  14. Effects of a laminin peptide (YIGSR) immobilized on crab-tendon chitosan tubes on nerve regeneration.

    Science.gov (United States)

    Itoh, Soichiro; Matsuda, Atsushi; Kobayashi, Hisatoshi; Ichinose, Shizuko; Shinomiya, Kenichi; Tanaka, Junzo

    2005-05-01

    Thiolated and nonthiolated hydroxyapatite-coated crab-tendon chitosan (t-chitosan/HAp-SH and t-chitosan/HAp, respectively) tubes, both alone and conjugated with CDPGYIGSR (YIGSR) peptide, were compared, in order to determine their biocompatibility and efficacy as nerve conduits. YIGSR peptide was adsorbed on the t-chitosan/HAp (HAp) tubes, and covalently bound on the t-chitosan/HAp-SH (HAp-SH) tubes (Y/HAp and Y/HAp-SH tubes, respectively). HAp, HAp-SH, Y/HAp, or Y/HAp-SH tubes measuring 15 mm were bridge grafted into the sciatic nerve of SD rats. Grafting of 15-mm-long Type I atelocollagen tubes and isografting of sciatic nerves were also carried out (N = 6 in each group). After 12 weeks, evoked muscle action potentials were recorded to calculate the terminal latency quotient. Histological observation and analysis of myelinated axons were also carried out. Nerve-tissue regeneration did not occur directly on the tubes' surfaces in the YIGSR peptide-unconjugated groups. Transplantation of YIGSR-conjugated tubes, however, gave rise to regenerated nerve tissue attached to thin layers of epineurium-like structure formed on the inner-tube surface. Histological and electrophysiological analyses suggested that although thiolation retards nerve-tissue regeneration, adsorbed YIGSR, and, to a lesser extent, peptide that had been covalently bound onto the tube surfaces, enhance nerve regeneration, promoting sprouting from the proximal nerve stump and bridging of regenerated axons throughout the tube.

  15. 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

  16. Management of Facial Nerve in Surgical Treatment of Previously Untreated Fisch Class C Tympanojugular Paragangliomas: Long-Term Results

    Science.gov (United States)

    Bacciu, Andrea; Ait Mimoune, Hassan; D'Orazio, Flavia; Vitullo, Francesca; Russo, Alessandra; Sanna, Mario

    2013-01-01

    The aim of this study was to evaluate the long-term facial nerve outcome according to management of the facial nerve in patients undergoing surgery for Fisch class C tympanojugular paragangliomas. The study population consisted of 122 patients. The infratemporal type A approach was the most common surgical procedure. The facial nerve was left in place in 2 (1.6%) of the 122 patients, anteriorly rerouted in 97 (79.5%), anteriorly rerouted with segmental resection of the epineurium in 7 (5.7%), and sacrificed and reconstructed in 15 (12.3%). One patient underwent cross-face nerve grafting. At last follow-up, House-Brackmann grade I to II was achieved in 51.5% of patients who underwent anterior rerouting and in 28.5% of those who underwent anterior rerouting with resection of the epineurium. A House-Brackmann grade III was achieved in 73.3% of patients who underwent cable nerve graft interposition. The two patients in whom the facial nerve was left in place experienced grade I and grade III, respectively. The patient who underwent cross-face nerve grafting had grade III. Gross total resection was achieved in 105 cases (86%). Management of the facial nerve in tympanojugular paraganglioma surgery can be expected to ensure satisfactory facial function long-term outcome. PMID:24498582

  17. 人工植骨结合二次球囊扩张在椎体后凸成形术中骨水泥外渗中的临床应用%Clinical application of artificial bone graft combined with the two balloon dilation in prevention of cement extravasation in percutaneous kyphoplasty

    Institute of Scientific and Technical Information of China (English)

    陶学顺; 余润泽; 张长春; 沈政; 曹参

    2014-01-01

    Objective To explore the clinical efficacy of cement extravasation prevention by artificial bone graft combined with the two balloon dilation for the treatment of osteoporotic vertebral compression fractures.Methods Clinical data of 60 cases with osteoporotic thoracolumbar vertebral compression fracture treated by the unilateral pedicle puncture percutaneous kyphoplasty (PKP) were retrospectively analyzed,including 15 cases(T11 3 cases,T12 3 cases,L1 5 cases,L2 2 cases,L4 1 case,L5 1 case) of contrast agent extravasation found in operation.The artificial bone was pressed into powder and tuned into a thick paste ; the thick paste was injected into the vertebral body by the injector.After the second balloon dilatation,bone cement like toothpaste was injected into the vertebral body slowly in X-ray fluoroscopy.Postoperative bone cement extravasation and kyphosis Cobb angle as well as visual analogue scale (VAS) score improvement were observed.According to the degree of pain reliesing evaluate the clinical curative effect.Results All 15 patients were completed the operation.The third day after the operation,the review X-ray showed a good recovery of vertebral height of each disease,the vertebral bone cement filling was good,evenly distributed,without intervertebral,paraspinal or spinal bone cement extravasation.The average Cobb angle of kyphosis was corrected 10.1 ° ± 2.4°,and the average VAS score was reduced by 6.2 ± 0.2.Compared with preoperation,the differences were statistically significant (tCobb =16.299,tvAs =120.062,all P values < 0.01).Fifteen cases were followed up for 4 weeks to 24 weeks,with an average of 19 weeks.The fourth week of the postoperative,X-ray showed that no significant vertebral height of each disease was missing,no new adjacent vertebral fracture was found.The efficacy was evaluated the fourth week after surgery,the symptoms of pain was disappeared or obviously improved,and the patients could walk normally.Among them,2 cases were

  18. Imaging the hypoglossal nerve

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Pedro [Department of Radiology, Centro Hospitalar de Lisboa Central-Hospital de Sao Jose, Rua Jose Antonio Serrano, 1150-199 Lisboa Codex (Portugal)], E-mail: tojais.pedro@gmail.com

    2010-05-15

    The hypoglossal nerve is a pure motor nerve. It provides motor control to the intrinsic and extrinsic tongue muscles thus being essential for normal tongue movement and coordination. In order to design a useful imaging approach and a working differential diagnosis in cases of hypoglossal nerve damage one has to have a good knowledge of the normal anatomy of the nerve trunk and its main branches. A successful imaging evaluation to hypoglossal diseases always requires high resolution studies due to the small size of the structures being studied. MRI is the preferred modality to directly visualize the nerve, while CT is superior in displaying the bony anatomy of the neurovascular foramina of the skull base. Also, while CT is only able to detect nerve pathology by indirect signs, such as bony expansion of the hypoglossal canal, MRI is able to visualize directly the causative pathological process as in the case of small tumors, or infectious/inflammatory processes affecting the nerve. The easiest way to approach the study of the hypoglossal nerve is to divide it in its main segments: intra-axial, cisternal, skull base and extracranial segment, tailoring the imaging technique to each anatomical area while bearing in mind the main disease entities affecting each segment.

  19. Suprascapular nerve palsy.

    Science.gov (United States)

    Moskowitz, E; Rashkoff, E S

    1989-11-01

    Isolated traumatic suprascapular nerve palsy without associated fracture is a rare occurrence. Localized segmental muscle atrophy limited to the supraspinatus and infraspinatus muscles associated with weakness in initiating abduction and in external rotation of the shoulder should suggest the diagnosis. Electromyography will confirm the diagnosis by excluding nerve root and brachial plexus involvement with denervation potentials limited to the supraspinatus and infraspinatus muscles.

  20. Primary renal graft thrombosis

    NARCIS (Netherlands)

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

    1996-01-01

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

  1. 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.

  2. Tissue-Engineered Nanofibrous Nerve Grafts for Enhancing the Rate of Nerve Regeneration

    Science.gov (United States)

    2014-10-01

    improve their bioactivity and assess the optimal concentration to incorporate and its stability. Polymeric blends and composite approach was adopted...These findings suggest that inclusion of gelatin in PCL improve matrix hydrophilicity and cell compatibility. Matrix degradation and other properties...applications: sulfonated ionic membranes Conductive polymers have found extensive application in fuel cells, sensors and more recently as scaffolds

  3. The efficacy of a scaffold-free Bio 3D conduit developed from human fibroblasts on peripheral nerve regeneration in a rat sciatic nerve model

    Science.gov (United States)

    Yurie, Hirofumi; Ikeguchi, Ryosuke; Aoyama, Tomoki; Kaizawa, Yukitoshi; Tajino, Junichi; Ito, Akira; Ohta, Souichi; Oda, Hiroki; Takeuchi, Hisataka; Akieda, Shizuka; Tsuji, Manami; Nakayama, Koichi; Matsuda, Shuichi

    2017-01-01

    Background Although autologous nerve grafting is the gold standard treatment of peripheral nerve injuries, several alternative methods have been developed, including nerve conduits that use supportive cells. However, the seeding efficacy and viability of supportive cells injected in nerve grafts remain unclear. Here, we focused on a novel completely biological, tissue-engineered, scaffold-free conduit. Methods We developed six scaffold-free conduits from human normal dermal fibroblasts using a Bio 3D Printer. Twelve adult male rats with immune deficiency underwent mid-thigh-level transection of the right sciatic nerve. The resulting 5-mm nerve gap was bridged using 8-mm Bio 3D conduits (Bio 3D group, n = 6) and silicone tube (silicone group, n = 6). Several assessments were conducted to examine nerve regeneration eight weeks post-surgery. Results Kinematic analysis revealed that the toe angle to the metatarsal bone at the final segment of the swing phase was significantly higher in the Bio 3D group than the silicone group (-35.78 ± 10.68 versus -62.48 ± 6.15, respectively; p < 0.01). Electrophysiological studies revealed significantly higher compound muscle action potential in the Bio 3D group than the silicone group (53.60 ± 26.36% versus 2.93 ± 1.84%; p < 0.01). Histological and morphological studies revealed neural cell expression in all regions of the regenerated nerves and the presence of many well-myelinated axons in the Bio 3D group. The wet muscle weight of the tibialis anterior muscle was significantly higher in the Bio 3D group than the silicone group (0.544 ± 0.063 versus 0.396 ± 0.031, respectively; p < 0.01). Conclusions We confirmed that scaffold-free Bio 3D conduits composed entirely of fibroblast cells promote nerve regeneration in a rat sciatic nerve model. PMID:28192527

  4. Sciatic nerve repair with tissue engineered nerve: Olfactory ensheathing cells seeded poly(lactic-co-glygolic acid conduit in an animal model

    Directory of Open Access Journals (Sweden)

    C W Tan

    2013-01-01

    Full Text Available Background and Aim: Synthetic nerve conduits have been sought for repair of nerve defects as the autologous nerve grafts causes donor site morbidity and possess other drawbacks. Many strategies have been investigated to improve nerve regeneration through synthetic nerve guided conduits. Olfactory ensheathing cells (OECs that share both Schwann cell and astrocytic characteristics have been shown to promote axonal regeneration after transplantation. The present study was driven by the hypothesis that tissue-engineered poly(lactic-co-glycolic acid (PLGA seeded with OECs would improve peripheral nerve regeneration in a long sciatic nerve defect. Materials and Methods: Sciatic nerve gap of 15 mm was created in six adult female Sprague-Dawley rats and implanted with PLGA seeded with OECs. The nerve regeneration was assessed electrophysiologically at 2, 4 and 6 weeks following implantation. Histopathological examination, scanning electron microscopic (SEM examination and immunohistochemical analysis were performed at the end of the study. Results: Nerve conduction studies revealed a significant improvement of nerve conduction velocities whereby the mean nerve conduction velocity increases from 4.2 ΁ 0.4 m/s at week 2 to 27.3 ΁ 5.7 m/s at week 6 post-implantation ( P < 0.0001. Histological analysis revealed presence of spindle-shaped cells. Immunohistochemical analysis further demonstrated the expression of S100 protein in both cell nucleus and the cytoplasm in these cells, hence confirming their Schwann-cell-like property. Under SEM, these cells were found to be actively secreting extracellular matrix. Conclusion: Tissue-engineered PLGA conduit seeded with OECs provided a permissive environment to facilitate nerve regeneration in a small animal model.

  5. Plasma-modified and polyethylene glycol-grafted polymers for potential tissue engineering applications.

    Science.gov (United States)

    Svorcík, V; Makajová, Z; Kasálková-Slepicková, N; Kolská, Z; Bacáková, L

    2012-08-01

    Modified and grafted polymers may serve as building blocks for creating artificial bioinspired nanostructured surfaces for tissue engineering. Polyethylene (PE) and polystyrene (PS) were modified by Ar plasma and the surface of the plasma activated polymers was grafted with polyethylene glycol (PEG). The changes in the surface wettability (contact angle) of the modified polymers were examined by goniometry. Atomic Force Microscopy (AFM) was used to determine the surface roughness and morphology and electrokinetical analysis (Zeta potential) characterized surface chemistry of the modified polymers. Plasma treatment and subsequent PEG grafting lead to dramatic changes in the polymer surface morphology, roughness and wettability. The plasma treated and PEG grafted polymers were seeded with rat vascular smooth muscle cells (VSMCs) and their adhesion and proliferation were studied. Biological tests, performed in vitro, show increased adhesion and proliferation of cells on modified polymers. Grafting with PEG increases cell proliferation, especially on PS. The cell proliferation was shown to be an increasing function of PEG molecular weight.

  6. Quadratus lumborum block for femoral–femoral bypass graft placement

    Science.gov (United States)

    Watanabe, Kunitaro; Mitsuda, Shingo; Tokumine, Joho; Lefor, Alan Kawarai; Moriyama, Kumi; Yorozu, Tomoko

    2016-01-01

    Abstract Introduction: Atherosclerosis has a complex etiology that leads to arterial obstruction and often results in inadequate perfusion of the distal limbs. Patients with atherosclerosis can have severe complications of this condition, with widespread systemic manifestations, and the operations undertaken are often challenging for anesthesiologists. Case report: A 79-year-old woman with chronic heart failure and respiratory dysfunction presented with bilateral gangrene of the distal lower extremities with obstruction of the left common iliac artery due to atherosclerosis. Femoral–femoral bypass graft and bilateral foot amputations were planned. Spinal anesthesia failed due to severe scoliosis and deformed vertebrae. General anesthesia was induced after performing multiple nerve blocks including quadratus lumborum, sciatic nerve, femoral nerve, lateral femoral cutaneous nerve, and obturator nerve blocks. However, general anesthesia was abandoned because of deterioration in systemic perfusion. The surgery was completed; the patient remained comfortable and awake without the need for further analgesics. Conclusion: Quadratus lumborum block may be a useful anesthetic technique to perform femoral–femoral bypass. PMID:27583851

  7. Spider silk constructs enhance axonal regeneration and remyelination in long nerve defects in sheep.

    Directory of Open Access Journals (Sweden)

    Christine Radtke

    Full Text Available BACKGROUND: Surgical reapposition of peripheral nerve results in some axonal regeneration and functional recovery, but the clinical outcome in long distance nerve defects is disappointing and research continues to utilize further interventional approaches to optimize functional recovery. We describe the use of nerve constructs consisting of decellularized vein grafts filled with spider silk fibers as a guiding material to bridge a 6.0 cm tibial nerve defect in adult sheep. METHODOLOGY/PRINCIPAL FINDINGS: The nerve constructs were compared to autologous nerve grafts. Regeneration was evaluated for clinical, electrophysiological and histological outcome. Electrophysiological recordings were obtained at 6 months and 10 months post surgery in each group. Ten months later, the nerves were removed and prepared for immunostaining, electrophysiological and electron microscopy. Immunostaining for sodium channel (NaV 1.6 was used to define nodes of Ranvier on regenerated axons in combination with anti-S100 and neurofilament. Anti-S100 was used to identify Schwann cells. Axons regenerated through the constructs and were myelinated indicating migration of Schwann cells into the constructs. Nodes of Ranvier between myelin segments were observed and identified by intense sodium channel (NaV 1.6 staining on the regenerated axons. There was no significant difference in electrophysiological results between control autologous experimental and construct implantation indicating that our construct are an effective alternative to autologous nerve transplantation. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that spider silk enhances Schwann cell migration, axonal regrowth and remyelination including electrophysiological recovery in a long-distance peripheral nerve gap model resulting in functional recovery. This improvement in nerve regeneration could have significant clinical implications for reconstructive nerve surgery.

  8. Changes in nerve microcirculation following peripheral nerve compression

    Institute of Scientific and Technical Information of China (English)

    Yueming Gao; Changshui Weng; Xinglin Wang

    2013-01-01

    Following peripheral nerve compression, peripheral nerve microcirculation plays important roles in regulating the nerve microenvironment and neurotrophic substances, supplying blood and oxygen and maintaining neural conduction and axonal transport. This paper has retrospectively analyzed the articles published in the past 10 years that addressed the relationship between peripheral nerve compression and changes in intraneural microcirculation. In addition, we describe changes in different peripheral nerves, with the aim of providing help for further studies in peripheral nerve microcirculation and understanding its protective mechanism, and exploring new clinical methods for treating peripheral nerve compression from the perspective of neural microcirculation.

  9. Study on biotribological properties of UHMWPE grafted with MPDSAH.

    Science.gov (United States)

    Deng, Yaling; Xiong, Dangsheng; Shao, Silong

    2013-04-01

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

  10. Carotid and cranial nerve reconstruction after removal of cavernous sinus lesions.

    Science.gov (United States)

    Sekhar, L N; Sen, C N; Lanzino, G; Pomonis, S

    1991-12-01

    During the last 7 years, approximately 170 neoplasms, and 35 vascular lesions involving the cavernous sinus were treated by the first two authors. During the treatment of such lesions, the direct vein graft reconstruction of the internal carotid artery from the petrous to the supraclinoid or infraclinoid ICA was performed in 23 patients. Graft occlusion occurred in 3 patients and in one of these, it was successfully salvaged by placing a long venous graft from the extracranial ICA to the M3 segment of the middle cerebral artery. The latter 3 patients were neurologically normal. One patient with significant atherosclerotic disease suffered the dissection of the distal internal carotid artery with the graft being patent. The suturing technique. This patient eventually died. Two patients with severely compromised collateral circulation suffered minor strokes due to the temporary occlusion of the ICA. This has been avoided in the more recent patients by the adoption of brain protection techniques such as moderate hypothermia, induced hypertension, and barbiturate coma. Low dose heparin therapy during grafting and high dose intravenous steroids prior to the grafting also appear to be beneficial. Direct vein graft reconstruction of the intracavernous carotid artery is a valuable tool during the management of cavernous sinus lesions. The advantages and disadvantages of this technique as well as the pros and cons of other revascularization techniques will be discussed. During microsurgical removal of cavernous sinus lesions, the cranial nerves III-VI were reconstructed by direct resuture or by nerve grafting in 16 patients. In the majority of these patients, recovery of cranial nerve function was observed, which was very encouraging.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. [Grafting of carotid arteries].

    Science.gov (United States)

    Belov, Iu V; Stepanenko, A B; Gens, A P; Bazylev, V V; Seleznev, M N; Savichev, D D

    2005-01-01

    Over 5-years, 167 reconstructive surgeries for stenosis of internal carotid arteries (ICA) were performed in 124 patients. Mean age of the patients was 63.5 years. One hundred and twenty-nine carotid endarterectomies (CEAE) in 86 patients and 38 reconstructive operations of ICA in 38 patients were performed. There were no lethal outcomes in short- and long-term postoperative period. In short-term period after prosthesis of ICA restenosis was revealed in 3% patients, after eversion CEAE in 3% patients the embolism was seen, after standard CEAE restenosis were diagnosed in 8% patients and thrombosis -- in 3%. In long-term period after grafting of ICA the strokes were seen in 3%, stenosis -- in 6% patients, after eversion endarterectomy -- in 0 and 3% patients, and after standard CEAE -- in 3 and 24% patients, respectively. It is concluded that grafting of ICA is adequate surgical method of reconstruction and stroke prevention in specific variants of carotid atherosclerosis.

  12. 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.

  13. Buccal Mucosal Graft Urethroplasty

    Directory of Open Access Journals (Sweden)

    Angela M. Arlen

    2010-01-01

    Full Text Available At our institution, the majority of buccal mucosal graft urethroplasties are performed using a two-team approach with an otolaryngologic surgeon. We report our two-surgeon experience with buccal mucosal grafting for reconstruction of all anterior urethral strictures. Twenty-four men underwent autologous buccal mucosal graft urethroplasty between October 2001 and September 2008 for recurrent urethral stricture disease. Twenty-two underwent a single-stage repair and two underwent a two-stage repair. Medical charts were retrospectively reviewed for demographics, comorbidities, etiology, location and length of stricture, and prior interventions in order to identify predictors of buccal urethroplasty success, defined as no evidence of stricture recurrence. All patients underwent retrograde urethrogram and cystoscopy. Operative and anesthesia times were evaluated. We determined an overall success rate of 83.3% (20 of 24 cases. Mean anesthesia time for single-stage urethroplasty was 155 min and mean operative time was 123 min. One of the two two-stage urethroplasties experienced stricture recurrence (50%. The single-stage buccal graft success rate was 86.4% (19 of 22 cases. Two of the four who developed recurrent stricture disease that required intervention had undergone a previous mesh urethroplasty. Complications developed in four of 24 patients (16.6%, including superficial wound infection (one, superficial wound dehiscence (two, and abscess/fistula formation requiring reoperation (one. The buccal mucosa is an ideal tissue for both single- and two-stage substitution urethroplasty for patients with recurrent stricture disease. Our two-surgeon technique minimizes anesthesia and operative times, and contributes to the overall high success rate and relatively low complication rate.

  14. 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....

  15. 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 of these diseases are genetic. Sometimes the cause is a medical ...

  16. Diabetes and nerve damage

    Science.gov (United States)

    Diabetic neuropathy; Diabetes - neuropathy; Diabetes - peripheral neuropathy ... In people with diabetes, the body's nerves can be damaged by decreased blood flow and a high blood sugar level. This condition is ...

  17. 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. ...

  18. Damaged axillary nerve (image)

    Science.gov (United States)

    Conditions associated with axillary nerve dysfunction include fracture of the humerus (upper arm bone), pressure from casts or splints, and improper use of crutches. Other causes include systemic disorders that cause neuritis (inflammation of ...

  19. Sacral nerve stimulation.

    Science.gov (United States)

    Matzel, K E; Stadelmaier, U; Besendörfer, M

    2004-01-01

    The current concept of recruiting residual function of an inadequate pelvic organ by electrostimulation involves stimulation of the sacral spinal nerves at the level of the sacral canal. The rationale for applying SNS to fecal incontinence was based on clinical observations of its effect on bowel habits and anorectal continence function in urologic patients (increased anorectal angulation and anal canal closure pressure) and on anatomic considerations: dissection demonstrated a dual peripheral nerve supply of the striated pelvic floor muscles that govern these functions. Because the sacral spinal nerve site is the most distal common location of this dual nerve supply, stimulating here can elicit both functions. Since the first application of SNS in fecal incontinence in 1994, this technique has been improved, the patient selection process modified, and the spectrum of indications expanded. At present SNS has been applied in more than 1300 patients with fecal incontinence limited.

  20. Conjoined lumbosacral nerve roots

    Directory of Open Access Journals (Sweden)

    Atila Yılmaz

    2012-03-01

    Full Text Available Lumbosacral nerve root anomalies are a rare group ofcongenital anatomical anomalies. Various types of anomaliesof the lumbosacral nerve roots have been documentedin the available international literature. Ttheseanomalies may consist of a bifid, conjoined structure, ofa transverse course or of a characteristic anastomizedappearance. Firstly described as an incidental findingduring autopsies or surgical procedures performed forlumbar disk herniations and often asymptomatic, lumbosacralnerve root anomalies have been more frequentlydescribed in the last years due to the advances made inradiological diagnosis.

  1. Anatomical study of sciatic nerve and common peroneal nerve compression

    Institute of Scientific and Technical Information of China (English)

    Mingzhao Jia; Qing Xia; Jinmin Sun; Qiang Zhou; Weidong Wang

    2008-01-01

    BACKGROUND: Many diseases of the common peroneal nerve are a result of sciatic nerve injury. The present study addresses whether anatomical positioning of the sciatic nerve is responsible for these injuries. OBJECTIVE: To analyze anatomical causes of sciatic nerve and common peroneal nerve injury by studying the relationship between the sciatic nerve and piriformis. DESIGN, TIME AND SETTING: Observe and measure repeatedly. The experiment was conducted in the Department of Anatomy, Tianjin Medical College between January and June 2005. MATERIALS: Fifty-two adult cadavers 33 males and 19 females, with a total of 104 hemispheres, and fixed with formaldehyde, were provided by Tianjin Medical College and Tianjin Medical University. METHODS: A posterior cut was made from the lumbosacral region to the upper leg, fully exposing the piriformis and path of the sciatic nerve. MAIN OUTCOME MEASURES: (1) Anatomical characteristics of the tibial nerve and common peroneal nerve. (2) According to different areas where the sciatic nerve crosses the piriformis, the study was divided into two types--normal and abnormal. Normal is considered to be when the sciatic nerve passes through the infrapiriform foramen. Remaining pathways are considered to be abnormal. (3) Observe the relationship between the suprapiriform foramen, infrapiriform foramen, as well as the superior and inferior space of piriformis. RESULTS: (1) The nerve tract inside the common peroneal nerve is smaller and thinner, with less connective tissue than the tibial nerve. When pathological changes or variations of the piriformis, or over-abduction of the hip joint, occur, injury to the common peroneal nerve often arises due to blockage and compression. (2) A total of 76 hemispheres (73.08%) were normal, 28 were abnormal (26.92%). The piriformis can be injured, and the sciatic nerve can become compressed, when the hip joint undergoes intorsion, extorsion, or abduction. (3) The structures between the infrapiriform and

  2. Restoration of contralateral representation in the mouse somatosensory cortex after crossing nerve transfer.

    Directory of Open Access Journals (Sweden)

    Haruyoshi Yamashita

    Full Text Available Avulsion of spinal nerve roots in the brachial plexus (BP can be repaired by crossing nerve transfer via a nerve graft to connect injured nerve ends to the BP contralateral to the lesioned side. Sensory recovery in these patients suggests that the contralateral primary somatosensory cortex (S1 is activated by afferent inputs that bypassed to the contralateral BP. To confirm this hypothesis, the present study visualized cortical activity after crossing nerve transfer in mice through the use of transcranial flavoprotein fluorescence imaging. In naïve mice, vibratory stimuli applied to the forepaw elicited localized fluorescence responses in the S1 contralateral to the stimulated side, with almost no activity in the ipsilateral S1. Four weeks after crossing nerve transfer, forepaw stimulation in the injured and repaired side resulted in cortical responses only in the S1 ipsilateral to the stimulated side. At eight weeks after crossing nerve transfer, forepaw stimulation resulted in S1 cortical responses of both hemispheres. These cortical responses were abolished by cutting the nerve graft used for repair. Exposure of the ipsilateral S1 to blue laser light suppressed cortical responses in the ipsilateral S1, as well as in the contralateral S1, suggesting that ipsilateral responses propagated to the contralateral S1 via cortico-cortical pathways. Direct high-frequency stimulation of the ipsilateral S1 in combination with forepaw stimulation acutely induced S1 bilateral cortical representation of the forepaw area in naïve mice. Cortical responses in the contralateral S1 after crossing nerve transfer were reduced in cortex-restricted heterotypic GluN1 (NMDAR1 knockout mice. Functional bilateral cortical representation was not clearly observed in genetically manipulated mice with impaired cortico-cortical pathways between S1 of both hemispheres. Taken together, these findings strongly suggest that activity-dependent potentiation of cortico

  3. Biomedical engineering strategies for peripheral nerve repair: surgical applications, state of the art, and future challenges.

    Science.gov (United States)

    Pfister, Bryan J; Gordon, Tessa; Loverde, Joseph R; Kochar, Arshneel S; Mackinnon, Susan E; Cullen, D Kacy

    2011-01-01

    Damage to the peripheral nervous system is surprisingly common and occurs primarily from trauma or a complication of surgery. Although recovery of nerve function occurs in many mild injuries, outcomes are often unsatisfactory following severe trauma. Nerve repair and regeneration presents unique clinical challenges and opportunities, and substantial contributions can be made through the informed application of biomedical engineering strategies. This article reviews the clinical presentations and classification of nerve injuries, in addition to the state of the art for surgical decision-making and repair strategies. This discussion presents specific challenges that must be addressed to realistically improve the treatment of nerve injuries and promote widespread recovery. In particular, nerve defects a few centimeters in length use a sensory nerve autograft as the standard technique; however, this approach is limited by the availability of donor nerve and comorbidity associated with additional surgery. Moreover, we currently have an inadequate ability to noninvasively assess the degree of nerve injury and to track axonal regeneration. As a result, wait-and-see surgical decisions can lead to undesirable and less successful "delayed" repair procedures. In this fight for time, degeneration of the distal nerve support structure and target progresses, ultimately blunting complete functional recovery. Thus, the most pressing challenges in peripheral nerve repair include the development of tissue-engineered nerve grafts that match or exceed the performance of autografts, the ability to noninvasively assess nerve damage and track axonal regeneration, and approaches to maintain the efficacy of the distal pathway and targets during the regenerative process. Biomedical engineering strategies can address these issues to substantially contribute at both the basic and applied levels, improving surgical management and functional recovery following severe peripheral nerve injury.

  4. 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....

  5. Effects of Motor versus Sensory Nerve Autografts on Peripheral Nerve Regeneration%不同神经移植体移植修复自体周围神经缺损时的再生效果比较

    Institute of Scientific and Technical Information of China (English)

    黄启顺; 甘萌; 郑怀远; 周学武; 周攀; 陈振兵

    2013-01-01

    目的 比较不同自体神经移植材料在移植修复周围混合神经缺损时的再生效果.方法 取45只SD大鼠,随机分成3组,分别切除0.5 cm右侧坐骨神经,建立神经缺损模型.运动神经移植组:取左侧后肢的股神经运动支移植修复缺损的坐骨神经;感觉神经移植组:取左侧后肢的腓肠神经移植修复缺损的坐骨神经;混合神经移植组:取左侧后肢的坐骨神经移植修复.分别于术后2、4和8周,采用神经夹捏实验测量神经再生长度,处死动物后取下术侧腓肠肌称取肌肉湿重.术后8周取胫神经远侧吻合口远端3 mm神经组织行甲苯胺蓝染色,同时电镜下观察神经纤维的直径及髓鞘的厚度,采用图像分析软件进行图片分析,计数神经纤维总数并计算神经纤维的密度.结果 神经再生长度,术后2周时3组间差异无统计学意义;术后4、8周时运动神经移植组及混合神经移植组大于感觉神经移植组(均P<0.05).腓肠肌湿重,术后2、4周时3组间差异无统计学意义;术后8周时运动神经移植组和混合神经移植组重于感觉神经移植组(均P<0.05).术后8周时,在运动神经移植组和混合神经移植组中可见大量神经纤维生长,神经纤维的数量、轴突的密度均大于感觉神经移植组(均P<0.05);再生神经轴突在运动神经移植组更加成熟.结论 不同的神经移植材料对自体神经移植再生效果有着显著影响.运动神经及混合神经移植修复自体周围神经缺损时的再生效果优于感觉神经移植.%Objective To compare effects of different autologous nerve grafts on the regeneration of the peripheral mixed nerve. Methods Nerve defect models were established by removing 0. 5 cm right sciatic nerve in SD rats (n= 45 ). Then ,the animals received motor ,sensory or mixed nerve grafts ,which originated from the femoral nerve ,sural nerve and sciatic nerve of the contralateral hind limb. At 2 ,4 and 8 weeks post

  6. 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)

  7. [Effect of embryonic anlage allografts of the rat spinal cord on growth of regenerating fibers of the recipient nerve].

    Science.gov (United States)

    Petrova, E S; Isaeva, E N

    2014-01-01

    A comparative study of the effect of tissue and suspension allografts of an embryonic spinal cord on regeneration of nerve fibers of impaired (by application of a ligature) sciatic nerve in rats was conducted. It was demonstrated that unlike tissue grafts that reach a large volume 21 and 60 days after transplantation, suspension grafts do not inhibit the growth of axons of the recipient to the periphery. It was established that introduction of a suspension of dissociated cells of the spinal cord embryonic anlages (but not fragments of these anlages) into the impaired sciatic nerve in rats results in an increase in the amount of myelinated regenerating nerve fibers of the recipient 60 days after the operation.

  8. 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.

  9. Assessing Donor Site Complications of Iliac Crest Bone Graft in Treatment of Scaphoid Nonunion

    Directory of Open Access Journals (Sweden)

    Davod Jafari

    2016-07-01

    Full Text Available Background Bone grafting is a common surgical technique to augment bone regeneration in orthopedic surgery. Autologous bone graft harvesting is the reliable treatment option and iliac crest is the most common harvesting site for healing bone fractures. However, the results of iliac crest bone graft harvesting are associated with morbidity and a number of complications. Objectives The aim of this study was to assess donor site complications of scaphoid nonunion, to find clinical outcomes and the impact of iliac crest bone graft on age, gender, pain, numbness, itching, nerve injury and scar appearance of patients. Methods In a prospective review of 61 cases of iliac crest bone graft procedures at the Shafa hospital from 2013 to 2014, complications including pain, infection, hematoma, stress fracture, hypertrophic scars, numbness area and itching were assessed clinically. Results Pain identified as the most common complication. The most common complications following postoperative pain at the donor site that reduced after six weeks were: numbness 3.27%, unsatisfactory scar appearance 3.27% and itching discomfort 1.63%. Conclusions Harvesting of iliac crest bone graft can be the ideal way to prepare graft procedures required surgery scaphoid nonunion fractures with minimal complications. Nevertheless, with an adequate preoperative planning and appropriate surgical technique, the prevalence of these complications can be reduced.

  10. Grafting a lubricious coating onto photo-crosslinked poly(trimethylene carbonate)

    NARCIS (Netherlands)

    van Bochove, Bas; Rongen, Jan J.; Hannink, Gerjon; van Tienen, Tony G.; Buma, Pieter; Grijpma, Dirk W.

    2015-01-01

    For biomaterial applications that involve moving parts such as artificial joints, lubricity is an essential property. Poly (trimethylene carbonate) networks are relatively hydrophobic. To create a lubricious layer, methacrylated poly(ethylene glycol) and methoxy-poly(ethylene glycol) were grafted on

  11. 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.

  12. Neuromuscular ultrasound of cranial nerves.

    Science.gov (United States)

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

    2015-04-01

    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 reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed.

  13. Graft selection in cerebral revascularization.

    Science.gov (United States)

    Baaj, Ali A; Agazzi, Siviero; van Loveren, Harry

    2009-05-01

    Cerebral revascularization constitutes an important treatment modality in the management of complex aneurysms, carotid occlusion, tumor, and moyamoya disease. Graft selection is a critical step in the planning of revascularization surgery, and depends on an understanding of graft and regional hemodynamics, accessibility, and patency rates. The goal of this review is to highlight some of these properties.

  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. Nerve allograft regeneration and immunological tolerance of rats with sciatic nerve transplantation after intragastric pretreatment with ultraviolet B-irradiated donor splenocytes

    Institute of Scientific and Technical Information of China (English)

    Rui Mi; Qiang Liu; Dou Wu

    2008-01-01

    BACKGROUND: Nerve allograft rejection is an unavoidable problem for nerve allografts. Traumatic peripheral nerve injuries are commonly reconstructed using autogenous nerve grafts. However, this form of reconstruction is limited by insufficient autologous nerves for large gap repairs and by morbidity at the nerve donor site.OBJECTIVE: To examine sciatic nerve regeneration and immune tolerance reaction after intragastric administration of ultraviolet B-irradiated (UVB) donor splenocytes.DESIGN, TIME AND SETTING: A complete randomized grouping design and controlled experiment. The experiments were conducted in the Department of Orthopedics, the First Affiliated Hospital to Shanxi Medical University, China, between March and October 2007.MATERIALS: Fourteen adult male SD rats and fourteen male Wistar rats, weighing 250-300g, were randomly matched as donors and acceptors. A further seven male SD rats (weight 250-300g, age 12-16 weeks) were used for nerve isografts. Immune preparations and the Epics XL flow cytometer were purchased from B-D Company, USA. A computer-assisted electromyograph machine was provided by Keypoint P, Dantel Company, Denmark.METHODS: Splenocytes from Wistar rats were isolated, purified, and cultured, and then irradiated with ultraviolet B. In the first control group (Group 1), the SD rats received a syngeneic SD nerve isograft. In the second control group (Group 2), the SD rats received a nerve allograft from Wistar rats without pretreatment. In the oral-tolerance treated group (Group 3), the SD recipient rats were inoculated with 2.5×107 Lewis UVB-irradiated donor splenocyte cells by intestinal tract administration at seven days before transplantation.MAIN OUTCOME MEASURES: (1) The recent end and the middle and distal end of the transplanted nerve were cut at 8 and 12 weeks after operation. Recovery of nerve regeneration was measured with HE staining using the total number, density, and diameter of the nerve fibers. (2) The level of CD25+T

  16. [Peripheral facial nerve palsy].

    Science.gov (United States)

    Pons, Y; Ukkola-Pons, E; Ballivet de Régloix, S; Champagne, C; Raynal, M; Lepage, P; Kossowski, M

    2013-06-01

    Facial palsy can be defined as a decrease in function of the facial nerve, the primary motor nerve of the facial muscles. When the facial palsy is peripheral, it affects both the superior and inferior areas of the face as opposed to central palsies, which affect only the inferior portion. The main cause of peripheral facial palsies is Bell's palsy, which remains a diagnosis of exclusion. The prognosis is good in most cases. In cases with significant cosmetic sequelae, a variety of surgical procedures are available (such as hypoglossal-facial anastomosis, temporalis myoplasty and Tenzel external canthopexy) to rehabilitate facial aesthetics and function.

  17. 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.

  18. Bilateral eventration of sciatic nerve

    Directory of Open Access Journals (Sweden)

    T Sharma

    2010-12-01

    Full Text Available During routine dissection of a 60 years male cadaver, it was observed that the two divisions of sciatic nerve were separate in the gluteal region on both the sides with the tibial nerve passing below the piriformis and the common peroneal nerve piercing the piriformis muscle. The abnormal passage of the sciatic nerve (SN, the common peroneal nerve (CPN, and the tibial nerve (TN, either through the piriformis or below the superior gemellus may facilitate compression of these nerves. Knowledge of such patterns is also important for surgeons dealing with piriformis syndrome which affects 5-6% of patients referred for the treatment of back and leg pain. A high division may also account for frequent failures reported with the popliteal block. Keywords: eventration, piriformis muscle, piriformis syndrome, sciatic nerve

  19. Tumors of the optic nerve

    DEFF Research Database (Denmark)

    Lindegaard, Jens; Heegaard, Steffen

    2009-01-01

    A variety of lesions may involve the optic nerve. Mainly, these lesions are inflammatory or vascular lesions that rarely necessitate surgery but may induce significant visual morbidity. Orbital tumors may induce proptosis, visual loss, relative afferent pupillary defect, disc edema and optic...... atrophy, but less than one-tenth of these tumors are confined to the optic nerve or its sheaths. No signs or symptoms are pathognomonic for tumors of the optic nerve. The tumors of the optic nerve may originate from the optic nerve itself (primary tumors) as a proliferation of cells normally present...... in 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...

  20. Nerve Injuries of the Upper Extremity

    Science.gov (United States)

    ... nerves do both of these things. Injury to nerves that carry motor signals causes some amount of weakness. Pain : This is frequently a symptom after nerve injury. The pain present after a nerve injury ...

  1. High division of sciatic nerve

    Directory of Open Access Journals (Sweden)

    Tripti Shrivastava

    2014-04-01

    Results: In all except two cadavers, the nerve divided at the apex of the popliteal fossa. In two cadavers the sciatic nerve divided bilaterally in the upper part of thigh. Conclusion: The high division presented in this study can make popliteal nerve blocks partially ineffective. The high division of sciatic nerve must always be borne in mind as they have important clinical implications. [Int J Res Med Sci 2014; 2(2.000: 686-688

  2. Trends in Artificial Intelligence.

    Science.gov (United States)

    Hayes, Patrick

    1978-01-01

    Discusses the foundations of artificial intelligence as a science and the types of answers that may be given to the question, "What is intelligence?" The paradigms of artificial intelligence and general systems theory are compared. (Author/VT)

  3. 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 block...

  4. 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.

  5. Imaging the ocular motor nerves.

    NARCIS (Netherlands)

    Ferreira, T.; Verbist, B.M.; Buchem, M. van; Osch, T. van; Webb, A.

    2010-01-01

    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 reso

  6. Nerve growth factor and injured peripheral nerve regeneration

    Institute of Scientific and Technical Information of China (English)

    Endong Shi; Bingchen Wang; Qingshan Sun

    2008-01-01

    Nerve growth factor (NGF) exhibits many biological activities, such as supply of nutrients, neuroprotection, and the generation and rehabilitation of injured nerves. The neuroprotective and neurotrophic qualities of NGF are generally recognized. NGF may enhance axonal regeneration and myelination of peripheral nerves, as well as cooperatively promote functional recovery of injured nerves and limbs. The clinical efficacy of NGF and its therapeutic potentials are reviewed here. This paper also reviews the latest NGF research developments for repairing injured peripheral nerve, thereby providing scientific evidence for the appropriate clinical application of NGF.

  7. Artificiality in Social Sciences

    OpenAIRE

    Rennard, Jean-Philippe

    2007-01-01

    This text provides with an introduction to the modern approach of artificiality and simulation in social sciences. It presents the relationship between complexity and artificiality, before introducing the field of artificial societies which greatly benefited from the computer power fast increase, gifting social sciences with formalization and experimentation tools previously owned by "hard" sciences alone. It shows that as "a new way of doing social sciences", artificial societies should undo...

  8. Artificial life and Piaget.

    Science.gov (United States)

    Mueller, Ulrich; Grobman, K H.

    2003-04-01

    Artificial life provides important theoretical and methodological tools for the investigation of Piaget's developmental theory. This new method uses artificial neural networks to simulate living phenomena in a computer. A recent study by Parisi and Schlesinger suggests that artificial life might reinvigorate the Piagetian framework. We contrast artificial life with traditional cognitivist approaches, discuss the role of innateness in development, and examine the relation between physiological and psychological explanations of intelligent behaviour.

  9. Motor evoked potentials enable differentiation between motor and sensory branches of peripheral nerves in animal experiments.

    Science.gov (United States)

    Turkof, Edvin; Jurasch, Nikita; Knolle, Erik; Schwendenwein, Ilse; Habib, Danja; Unger, Ewald; Reichel, Martin; Losert, Udo

    2006-10-01

    Differentiation between motor and sensory fascicles is frequently necessary in reconstructive peripheral nerve surgery. The goal of this experimental study was to verify if centrally motor evoked potentials (MEP) could be implemented to differentiate sensory from motor fascicles, despite the well-known intermingling between nerve fascicles along their course to their distant periphery. This new procedure would enable surgeons to use MEP for placing nerve grafts at corresponding fascicles in the proximal and distal stumps without the need to use time-consuming staining. In ten sheep, both ulnar nerves were exposed at the terminal bifurcation between the last sensory and motor branch. Animals were then relaxed to avoid volume conduction. On central stimulation, the evoked nerve compound action potentials were simultaneously recorded from both terminal branches. In all cases, neurogenic motor nerve action potentials were recorded only from the terminal motor branch. The conclusion was that MEPs can be used for intraoperative differentiation between sensory and motor nerves. Further studies are necessary to develop this method for in situ measurements on intact nerve trunks.

  10. The masseteric nerve: a versatile power source in facial animation techniques.

    Science.gov (United States)

    Bianchi, B; Ferri, A; Ferrari, S; Copelli, C; Salvagni, L; Sesenna, E

    2014-03-01

    The masseteric nerve has many advantages including low morbidity, its proximity to the facial nerve, the strong motor impulse, its reliability, and the fast reinnervation that is achievable in most patients. Reinnervation of a neuromuscular transplant is the main indication for its use, but it has been used for the treatment of recent facial palsies with satisfactory results. We have retrospectively evaluated 60 patients who had facial animation procedures using the masseteric nerve during the last 10 years. The patients included those with recent, and established or congenital, unilateral and bilateral palsies. The masseteric nerve was used for coaptation of the facial nerve either alone or in association with crossfacial nerve grafting, or for the reinnervation of gracilis neuromuscular transplants. Reinnervation was successful in all cases, the mean (range) time being 4 (2-5) months for facial nerve coaptation and 4 (3-7) months for neuromuscular transplants. Cosmesis was evaluated (moderate, n=10, good, n=30, and excellent, n=20) as was functional outcome (no case of impairment of masticatory function, all patients able to smile, and achievement of a smile independent from biting). The masseteric nerve has many uses, including in both recent, and established or congenital, cases. In some conditions it is the first line of treatment. The combination of combined techniques gives excellent results in unilateral palsies and should therefore be considered a valid option.

  11. Graft stability after endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Jovanović Vesna

    2015-01-01

    Full Text Available Bacground/Aim. Techniques for replacing the corneal endothelium have been improved. The host-graft interface is the key to graft adhesion and visual recovery. The aim of this study was to establish graft stability after Descemet stripping with endothelial keratoplasty (DSEK, compare it to the graft stability after endothelial keratoplasty with the intact posterior corneal layers (nDSEK in the rabbit cornea, and to investigate the nature of wound healing. Methods. Adult white rabbits (n = 20 were divided in two experimental groups: ten rabbits underwent monocular DSEK, and ten rabbits underwent endothelial keratoplasty without Descemet stripping (nDSEK. On the second postoperative day a horizontal dislocation of the graft was tried using the Lindstrom roller in each animal. Corneas were processed for the light microscopy study. Results. Rolling the Lindstrom instrument over the corneal surface did not cause horizontal dislocation in any of the operated eyes. In the DSEK group light microscopy revealed the lack of inflammation and fibrosis at the clearly distinctive donor-recipient interface (DRI. Retrocorneal membrane was found in two eyes. In nDSEK group, the host Descemet` s membrane (DM was intact without endothelial cells, with good graft apposition, without inflammation, fibrosis, or retrocorneal membrane. Conclusion. This study suggests that there is no difference in graft stability in DSEK compared to nDSEK in rabbit corneas. Wounds healed at DRI by hypocellular scarring only in both experimental groups.

  12. Transduction of anti-cell death protein FNK suppresses graft degeneration after autologous cylindrical osteochondral transplantation.

    Science.gov (United States)

    Nakachi, Noriki; Asoh, Sadamitsu; Watanabe, Nobuyoshi; Mori, Takashi; Matsushita, Takashi; Takai, Shinro; Ohta, Shigeo

    2009-03-01

    This study shows that artificial super antiapoptotic FNK protein fused with a protein transduction domain (PTD-FNK) maintains the quality of osteochondral transplant by preventing chondrocyte death. Cylindrical osteochondral grafts were obtained from enhanced green fluorescent protein (EGFP)-expressing transgenic rats, in which living chondrocytes express green fluorescence, and submerged into medium containing PTD-FNK, followed by transplantation into cartilage defects of wild-type rats by impact insertion simulating autologous transplantation. The tissues were histologically evaluated by hematoxylin-eosin and Safranin-O staining. At 1 week, chondrocyte alignment was normal in the PTD-FNK treatment group, whereas all grafts without PTD-FNK treatment showed mixed cluster cell distribution. At 4 weeks, all grafts with PTD-FNK treatment showed almost normal matrix, whereas two grafts without PTD-FNK treatment showed fibrocartilage. Notably, all grafts with PTD-FNK retained high intensity of Safranin-O staining, but all grafts without PTD-FNK largely lost Safranin-O staining. PTD-FNK significantly suppressed a decrease in the survival rate and the density of EGFP-positive cells at 1 and 2 weeks, and this tendency continued at 4 weeks. The results of terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-nick end-labeling staining showed that PTD-FNK inhibited cell death, indicating that PTD-FNK protects chondrocyte death and suppresses graft degeneration.

  13. Preparation and characterization of acrylic acid-grafted poly (vinyl alcohol) hydrogel actuators using γ-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    An, Sung Jun; Lim, Youn Mook; Gwon, Hui Jeong; Kim, Yun Hye; Youn, Min Ho; Nho, Young Chang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Han, Dong Hyun; Kim, Chong Yeal [Dept. of Radiation Science AND Technology, Graduate School of Chonbuk National University, Jeonju (Korea, Republic of)

    2008-01-15

    Active polymer gels expand and contract in response to certain environmental stimuli, such as the application of an electric field or a change in the pH level of the surroundings. This ability to achieve large, reversible deformations with no external mechanical loading has generated much interest in the use of these gels as biomimetic actuators and artificial muscles. In this study, poly (vinyl alcohol)(PVA) grafted acrylic acid monomer (PVA-g-AAc) hydrogels were prepared by {sup 60}Co γ-ray irradiation and their properties such as degree of grafting and weight swelling in electrostimulation as an artificial muscle and actuator were investigated.

  14. 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.

  15. 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.

  16. Design of a Sapling Branch Grafting Robot

    Directory of Open Access Journals (Sweden)

    Qun Sun

    2014-01-01

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

  17. Influence of calcium alginate on peripheral nerve regeneration: in vivo study.

    Science.gov (United States)

    Szarek, Dariusz; Marycz, Krzysztof; Bednarz, Paulina; Tabakow, Paweł; Jarmundowicz, Włodzimierz; Laska, Jadwiga

    2013-01-01

    Recently, we described the influence of sodium alginate on the inflammatory infiltrate during neuroregeneration in tube nerve grafts. It was noticeable that there was the coexistence of inflammatory cells, including neutrophils, plasma cells, and macrophages with Schwann cells and axons. This may indicate a beneficial interaction between alginates and the infiltrate and the additional beneficial effect of the cells on the neuroregeneration process in the inflammatory infiltrates. In this study, we have performed in vivo evaluation of our novel tubular implant prepared by a polyurethane/polylactide blend filled with alginate fibers. The influence of filling the lumen of the tubes with sodium and calcium alginates on the regeneration process of the rat sciatic nerve was investigated. The neuroregeneration process was assessed by detailed histomorphometric studies, axon counting, and calculating the regenerative indexes. It was observed that calcium alginate had a supportive effect on nerve regeneration similar to nerve autotransplant.

  18. 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.

  19. Can amino-functionalized carbon nanotubes carry functional nerve growth factor?

    Institute of Scientific and Technical Information of China (English)

    Wen Chen; Qing Xiong; Quanxia Ren; Yake Guo; Gao Li

    2014-01-01

    Carbon nanotubes can carry protein into cells to induce biological effects. Amino-functionalized carbon nanotubes are soluble and biocompatible, have high reactivity and low toxicity, and can help promote nerve cell growth. In this study, amino-functionalized ethylenediamine-treated multi-walled carbon nanotubes were used to prepare carbon nanotubes-nerve growth factor complexes by non-covalent grafting. The physicochemical properties, cytotoxicity to PC12 and chick embryo dorsal root ganglion, and biological activity of the carbon nanotubes-nerve growth factor complexes were investigated. The results showed that amino functionalization improved carbon nanotubes-nerve growth factor complex dispersibility, reduced their toxicity to PC12 cells, and promoted PC12 cell differentiation and chick embryo dorsal root ganglion.

  20. Nanoparticles carrying neurotrophin-3-modified Schwann cells promote repair of sciatic nerve defects

    Institute of Scientific and Technical Information of China (English)

    Haibin Zong; Hongxing Zhao; Yilei Zhao; Jingling Jia; Libin Yang; Chao Ma; Yang Zhang; Yuzhen Dong

    2013-01-01

    Schwann cells and neurotrophin-3 play an important role in neural regeneration, but the secretion of neurotrophin-3 from Schwann cells is limited, and exogenous neurotrophin-3 is inactived easily in vivo. In this study, we have transfected neurotrophin-3 into Schwann cells cultured in vitro using nanoparticle liposomes. Results showed that neurotrophin-3 was successfully transfected into Schwann cells, where it was expressed effectively and steadily. A composite of Schwann cells transfected with neurotrophin-3 and poly(lactic-co-glycolic acid) biodegradable conduits was transplanted into rats to repair 10-mm sciatic nerve defects. Transplantation of the composite scaffold could restore the myoelectricity and wave amplitude of the sciatic nerve by electrophysiological examination, promote nerve axonal and myelin regeneration, and delay apoptosis of spinal motor neurons. Experimental findings indicate that neurotrophin-3 transfected Schwann cells combined with bridge grafting can promote neural regeneration and functional recovery after nerve injury.

  1. Anatomic variations of superficial peroneal nerve: clinical implications of a cadaver study.

    Science.gov (United States)

    Prakash; Bhardwaj, Ajay Kumar; Singh, Deepak Kumar; Rajini, T; Jayanthi, V; Singh, Gajendra

    2010-01-01

    Superficial peroneal nerve and its branches are frequently at risk for iatrogenic damage. Although different studies on anatomical variations of superficial peroneal nerve are available in the medical literature, such reports are rare from India. Hence the present study was undertaken on Indian population. A total of 60 specimens of inferior extremities from 30 properly embalmed and formalin fixed cadavers were dissected and examined for the location and course of the superficial peroneal nerve including number, level, course and distributions of branches. The superficial peroneal nerve in 28.3% specimens was located in the anterior compartment of the leg. In 8.3% specimens the superficial peroneal nerve branched before piercing between the peroneus longus and extensor digitorum longus muscle whereas in 11.7% specimens it branched after piercing the aforementioned muscles and before piercing the deep fascia. In 41 out of 60 specimens the sensory division of superficial peroneal nerve branched into the medial dorsal cutaneous nerve and intermediate dorsal cutaneous nerve distal to its emergence from the deep fascia and proximal to its relation to the extensor retinaculum. In 20 out of 60 specimens the accessory deep peroneal nerve, an additional branch from the sensory division of superficial peroneal nerve, through its course in the anterior compartment of the leg passed deep to the extensor retinaculum and supplied the ankle and the dorsum of foot. Hopefully the present study will help in minimizing iatrogenic damage to the superficial peroneal nerve and its branches while performing arthroscopy, local anesthetic block, surgical approach to the fibula, open reduction and internal fixation of lateral malleolar fractures, application of external fixators, elevation of a fasciocutaneous or fibular flaps for grafting, surgical decompression of neurovascular structures, or miscellaneous surgery on leg, foot and ankle.

  2. 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.

  3. Muscarinic receptor-mediated calcium changes in a rat model of facial nerve nucleus injury

    Institute of Scientific and Technical Information of China (English)

    Dawei Sun; Huamin Liu; Fugao Zhu; Yanqing Wang; Junfeng Wen; Rui Zhou; Yanjun Wang; Banghua Liu

    2010-01-01

    The muscarinic receptor modulates intracellular free calcium ion levels in the facial nerve nucleus via different channels.In the present study,muscarinic receptor-mediated free calcium ions levels were detected by confocal laser microscopy in the facial nerve nucleus following facial nerve injury in rats.There was no significant difference in muscarinic receptor expression at the affected facial nerve nucleus compared with expression prior to injury,but muscarinic receptor-mediated free calcium ion levels increased in the affected side following facial nerve injury(P < 0.01).At day 30after facial nerve injury,50 μmol/L muscarinic-mediated free calcium ion levels were significantly inhibited at the affected facial nerve nucleus in calcium-free artificial cerebrospinal fluid,and the change range was 82% of artificial cerebrospinal fluid(P < 0.05).These results suggest that increased free calcium ion concentrations are achieved by intracellular calcium ion release,and that the transmembrane flow of calcium ions is also involved in this process.

  4. Novel block, graft and random copolymers for biomedical applications

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Jankova Atanasova, Katja; Tanaka, Masaru;

    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...... 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....

  5. Vascular graft infections with Mycoplasma

    DEFF Research Database (Denmark)

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

    1995-01-01

    Vascular graft infection is one of the most serious complications in vascular surgery. It is associated with mortality rates ranging from 25% to 75% and with morbidity in the form of amputation in approximately 30% of patients. Staphylococcus aureus is the leading pathogen. With conventional...... 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....

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

    Institute of Scientific and Technical Information of China (English)

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

    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 ifltering principle of hair cells, external voice sig-nals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass ifltering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequen-cy analysis, the frequency range of the band-pass iflter can also be determined. These ifndings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to dis-tinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes’ hearing problems. Scientiifc hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized.

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

    Science.gov (United States)

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

    2014-08-15

    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 frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequency analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to distinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes' hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized.

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

    Energy Technology Data Exchange (ETDEWEB)

    Easterling, K.J.; Trumble, T.E. (Yale Univ. School of Medicine, New Haven, CT (USA))

    1990-10-01

    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.

  9. Microsurgical management of complex fingertip injuries: comparison to conventional skin grafting.

    Science.gov (United States)

    Rose, E H; Norris, M S; Kowalski, T A

    1988-01-01

    In selected cases of severe fingertip injuries, an aggressive approach using microvascular and microneural techniques can yield functional results equal or superior to conventional methods of treatment in less severe injuries. A series of 20 patients were treated microsurgically from 1983 to 1986 for severe acute distal finger injuries or their early sequelae--five distal replantations, eight neurovascular free tissue transfers, and nine distal neurorrhaphies/nerve grafts with or without vascular conduit. Concurrently, 33 simpler tip avulsions were treated with full-thickness skin grafts for comparison. In the microsurgical series, one replant and the distal 1 cm of a free toe flap necrosed. Replants averaged two-point discrimination of 9.8 mm and pulp pinch 65 percent of normal; free toe transfers, two-point of 6 mm, pulp pinch 58 percent; distal nerve reconstruction, two-point 6 mm. Operating time per digit averaged 5.0 hours for replants, 4.3 hours for toe flaps, and 1.5 hours for nerve repair/grafts. All patients returned to full pre-injury employment within six months. None required revisional surgery for dysesthetic fingertips. In the conventional skin graft series, greater than six months follow-up is available in 17 patients. Average two-point was 7 mm (range: 3 to greater than 15 mm) and pulp pinch 83 percent of normal. There were seven poor results with cold intolerance, numbness, and paresthesias, three of which required revisional surgery. The data suggest that microsurgical management of fingertip injuries achieves results comparable to skin grafts, despite the greater complexity of the initial injury. This approach has resulted in fewer secondary tip revisions. Operative times are acceptable. Parameters of sensory return are similar, although pulp pinch is slightly less. Disability times are comparable to the average in major pulp losses. Of importance, final permanent partial factors of disability are diminished in rating, due to retained digital

  10. Tissue engineering and peripheral nerve regeneration (III) -- Sciatic nerve regeneration with PDLLA nerve guide

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The biodegradation rate and biocompatibility of poly(d, l -lactide) (PDLLA) in vivo were evaluated. The aim of this study was to establish a nerve guide constructed by the PDLLA with 3-D microenvironment and to repair a 10 mm of sciatic nerve gap in rats. The process of the nerve regeneration was investigated by histological assessment, electrophysiological examination, and determination of wet weight recovery rate of the gastrocnemius muscle. After 3 weeks, the nerve guide had changed from a transparent to an opaque status. The conduit was degraded and absorbed partly and had lost their strength with breakage at the 9th week of postoperation. At the conclusion of 12 weeks, proximal and distal end of nerves were anastomosed by nerve regeneration and the conduit vanished completely. The results suggest that PDLLA conduits may serve for peripheral nerve regeneration and PDLLA is a sort of hopeful candidate for tissue engineering.

  11. 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.

  12. 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.

  13. Combination of Local Transplantation of In Vitro Bone-marrow Stromal Cells and Pulsed Electromagnetic Fields Accelerate Functional Recovery of Transected Sciatic Nerve Regeneration: A Novel Approach in Transected Nerve Repair.

    Science.gov (United States)

    Mohammadi, Rahim; Mahmoodzadeh, Sirvan

    2015-01-01

    Effect of combination of undifferentiated bone marrow stromal cells (BMSCs) and pulsed electromagnetic fields (PEMF) on transected sciatic nerve regeneration was assessed in rats. A 10 mm nerve segment was excised and a vein graft was used to bridge the gap. Twenty microliter undifferentiated BMSCs (2× 107 cells /mL) were administered into the graft inBMSC group with no exposure to PEMF. In BMSC/PEMF group the whole body was exposed to PEMF (0.3 mT, 2Hz) for 4h/day within 1-5 days. In PEMF group the transected nerve was bridged and phosphate buffered saline was administered into the graft. In authograft group (AUTO), the transected nervesegments were reimplanted reversely and the whole body was exposed to PEMF. The regenerated nerve fibers were studied within 12 weeks after surgery. Behavioral, functional, electrophysiological, biomechanical, gastrocnemius muscle mass findings, morphometric indices and immuonohistochemical reactions confirmed faster recovery of regenerated axons in BMSC/PEMF group compared to those in the other groups (Pelectromagnetic fields could be considered as an effective, safe and tolerable treatment for peripheral nerve repair in clinical practice.

  14. 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.

  15. 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.

  16. 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.

  17. [Electrical nerve stimulation for plexus and nerve blocks].

    Science.gov (United States)

    Birnbaum, J; Klotz, E; Bogusch, G; Volk, T

    2007-11-01

    Despite the increasing use of ultrasound, electrical nerve stimulation is commonly used as the standard for both plexus and peripheral nerve blocks. Several recent randomized trials have contributed to a better understanding of physiological and clinical correlations. Traditionally used currents and impulse widths are better defined in relation to the distance between needle tip and nerves. Commercially available devices enable transcutaneous nerve stimulation and provide new opportunities for the detection of puncture sites and for training. The electrically ideal position of the needle usually is defined by motor responses which can not be interpreted without profound anatomical knowledge. For instance, interscalene blocks can be successful even after motor responses of deltoid or pectoral muscles. Infraclavicular blocks should be aimed at stimulation of the posterior fascicle (extension). In contrast to multiple single nerve blocks, axillary single-shot blocks more commonly result in incomplete anaesthesia. Blockade of the femoral nerve can be performed without any nerve stimulation if the fascia iliaca block is used. Independently of the various approaches to the sciatic nerve, inversion and plantar flexion are the best options for single-shot blocks. Further clinical trials are needed to define the advantages of stimulating catheters in continuous nerve blocks.

  18. Functional self-assembling peptide nanofiber hydrogel for peripheral nerve regeneration.

    Science.gov (United States)

    Wu, Xiaoli; He, Liumin; Li, Wen; Li, Heng; Wong, Wai-Man; Ramakrishna, Seeram; Wu, Wutian

    2017-02-01

    Peripheral nerves are fragile and easily damaged, usually resulting in nervous tissue loss, motor and sensory function loss. Advances in neuroscience and engineering have been significantly contributing to bridge the damage nerve and create permissive environment for axonal regrowth across lesions. We have successfully designed two self-assembling peptides by modifying RADA 16-I with two functional motifs IKVAV and RGD. Nanofiber hydrogel formed when combing the two neutral solutions together, defined as RADA 16-Mix that overcomes the main drawback of RADA16-I associated with low pH. In the present study, we transplanted the RADA 16-Mix hydrogel into the transected rat sciatic nerve gap and effect on axonal regeneration was examined and compared with the traditional RADA16-I hydrogel. The regenerated nerves were found to grow along the walls of the large cavities formed in the graft of RADA16-I hydrogel, while the nerves grew into the RADA 16-Mix hydrogel toward distal position. RADA 16-Mix hydrogel induced more axons regeneration and Schwann cells immigration than RADA16-I hydrogel, resulting in better functional recovery as determined by the gait-stance duration percentage and the formation of new neuromuscular junction structures. Therefore, our results indicated that the functional SAP RADA16-Mix nanofibrous hydrogel provided a better environment for peripheral nerve regeneration than RADA16-I hydrogel and could be potentially used in peripheral nerve injury repair.

  19. 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

  20. 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.

  1. Chapter 23: Manual stimulation of target muscles has different impact on functional recovery after injury of pure motor or mixed nerves.

    Science.gov (United States)

    Sinis, Nektarios; Manoli, Thodora; Werdin, Frank; Kraus, Armin; Schaller, Hans E; Guntinas-Lichius, Orlando; Grosheva, Maria; Irintchev, Andrey; Skouras, Emanouil; Dunlop, Sarah; Angelov, Doychin N

    2009-01-01

    Direct coaptation and interpositional nerve grafting (IPNG) of an injured peripheral nerve is still associated with poor functional recovery. Main reasons for that are thought to be an extensive collateral axonal branching at the site of transection and the polyinnervation of motor endplates due to terminal axonal and intramuscular sprouting. Moreover, severe changes occurring within the muscle after long-term denervation, like loss of muscle bulk and circulation as well as progressive fibrosis, have a negative effect on the quality of functional recovery after reinnervation. We have recently shown that manual stimulation (MS) of paralyzed vibrissal muscles in rat promotes full recovery after facial nerve coaptation. Furthermore, MS improved functional recovery after hypoglossal nerve repair, hypoglossal-facial IPNG of the facial nerve in rat. In contrary, MS did not improve recovery after injury of the median nerve in rat, which is however a mixed peripheral nerve comparing to the facial nerve. It is speculated that manually stimulated recovery of motor function requires an intact sensory input, which is affected in case of mixed peripheral nerves but not in case of pure motor nerves. In this article, we summarize our results of MS in several peripheral nerve injury models in order to illustrate the application potential of this method and to give insights into further investigations on that field.

  2. 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.

  3. Synthetic biodegradable nerve conduits for repair of injured peripheral nerve:good biocompatibility%合成可生物降解神经导管修复损伤周围神经:生物相容性良好

    Institute of Scientific and Technical Information of China (English)

    张孙富; 王斌

    2015-01-01

    BACKGROUND:In the treatment of peripheral nerve injury, we can use autologous nerve or the nerve conduit of different materials. OBJECTIVE:To explore the effects of biodegradable nerve conduit in repairing peripheral nerve injury. METHODS:A total of 48 New Zealand white rabbits were randomly divided into autologous nerve graft group, silicone catheter group and biodegradable nerve conduit group. 10-mm sciatic nerve was obtained from each group to construct animal models of sciatic nerve defect, which was repaired with autologous nerve, silicone catheter and biodegradable nerve conduit. RESULTS AND CONCLUSION:At 3 weeks after transplantation, motor nerve conduction and recovery rate of triceps muscle wet weight were poorer in the silicone catheter group than in the autologous nerve graft group. Motor nerve conduction and recovery rate of triceps muscle wet weight were similar between the biodegradable nerve conduit group and autologous nerve graft group. At 12 weeks, a large number of uniform myelinated nerve fiber was visible in the autologous nerve graft group. A large number of uneven myelinated nerve fiber was found in the biodegradable nerve conduit group. A smal number of uneven myelinated nerve fiber was seen in the silicone catheter group. These data suggest that the synthetic biodegradable materials of nerve conduit can obtain good effect, which is close to the autologous nerve graft.%背景:临床对周围神经损伤进行修复治疗的时候,可以利用自体神经进行治疗或者利用不同材质的神经导管进行治疗。目的:探索合成可生物降解材料神经导管在周围神经损伤修复中的应用效果。方法:48只新西兰大白兔,随机等分为3组,自体神经移植组、硅胶导管组和可降解神经导管组。各组动物切除10 mm坐骨神经,构建坐骨神经缺损动物模型,并分别利用自体神经、硅胶导管以及可降解神经导管进行坐骨神经修复

  4. Neurolytic blockade of the obturator nerve in the treatment of idiopatic obturator neuralgia

    OpenAIRE

    Ćulafić Slobodan; Spaić Milan; Zoranović Uroš; Mišović Sidor

    2008-01-01

    Introduction. Idiopathic obturator neuralgia is a rare chronic pain condition. It consists of pain radiating from the obturator nerve territory to the inner thigh. However, the symptomatic obturator neuralgia is commonly caused by the obturator canal bowel hernia that causes painful compressive neuropathy in more than 85% of the cases. Case report. A 61-year-old female who underwent right femoral amputation due to the occlusion of the aortofemoral vascular graft, complained of the pain charac...

  5. On Artificial and Animal Electricity : Alessandro Volta vs. Luigi Galvani

    OpenAIRE

    2013-01-01

    Two Italians, Alessandro Volta (1745–1827), a physicist, and Luigi Galvani (1737–1798), an obstetrician and physiologist, separately conducted experiments on dead frogs using metals that made their legs twitch. Volta concluded that electricity was an artificial and external phenomenon, dependent on the metals and unrelated with the frog’s body; Galvani concluded that the frog’s movement proved that there was such a thing as animal electricity that, even after life, remained stored in nerves a...

  6. 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.

  7. Wear resistance of the biocompatible phospholipid polymer-grafted highly cross-linked polyethylene liner against larger femoral head.

    Science.gov (United States)

    Moro, Toru; Takatori, Yoshio; Kyomoto, Masayuki; Ishihara, Kazuhiko; Kawaguchi, Hiroshi; Hashimoto, Masami; Tanaka, Takeyuki; Oshima, Hirofumi; Tanaka, Sakae

    2015-07-01

    The use of larger femoral heads to prevent the dislocation of artificial hip joints has recently become more common. However, concerns about the subsequent use of thinner polyethylene liners and their effects on wear rate have arisen. Previously, we prepared and evaluated the biological and mechanical effects of a novel highly cross-linked polyethylene (CLPE) liner with a nanometer-scaled graft layer of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC). Our findings showed that the PMPC-grafted particles were biologically inert and caused no subsequent bone resorptive responses and that the PMPC-grafting markedly decreased wear in a hip joint simulator. However, the metal or ceramic femoral heads used in this previous study had a diameter of 26 mm. Here, we investigated the wear-resistance of the PMPC-grafted CLPE liner with a 40-mm femoral head during 10 × 10(6) cycles of loading in the hip joint simulator. The results provide preliminary evidence that the grafting markedly decreased gravimetric wear rate and the volume of wear particles, even when coupled with larger femoral heads. Thus, we believe the PMPC-grafting will prolong artificial hip joint longevity both by preventing aseptic loosening and by improving the stability of articular surface.

  8. Heart Rate Changes in Response to Mechanical Pressure Stimulation of Skeletal Muscles Are Mediated by Cardiac Sympathetic Nerve Activity

    Science.gov (United States)

    Watanabe, Nobuhiro; Hotta, Harumi

    2017-01-01

    Stimulation of mechanoreceptors in skeletal muscles such as contraction and stretch elicits reflexive autonomic nervous system changes which impact cardiovascular control. There are pressure-sensitive mechanoreceptors in skeletal muscles. Mechanical pressure stimulation of skeletal muscles can induce reflex changes in heart rate (HR) and blood pressure, although the neural mechanisms underlying this effect are unclear. We examined the contribution of cardiac autonomic nerves to HR responses induced by mechanical pressure stimulation (30 s, ~10 N/cm2) of calf muscles in isoflurane-anesthetized rats. Animals were artificially ventilated and kept warm using a heating pad and lamp, and respiration and core body temperature were maintained within physiological ranges. Mechanical stimulation was applied using a stimulation probe 6 mm in diameter with a flat surface. Cardiac sympathetic and vagus nerves were blocked to test the contribution of the autonomic nerves. For sympathetic nerve block, bilateral stellate ganglia, and cervical sympathetic nerves were surgically sectioned, and for vagus nerve block, the nerve was bilaterally severed. In addition, mass discharges of cardiac sympathetic efferent nerve were electrophysiologically recorded. Mechanical stimulation increased or decreased HR in autonomic nerve-intact rats (range: −56 to +10 bpm), and the responses were negatively correlated with pre-stimulus HR (r = −0.65, p = 0.001). Stimulation-induced HR responses were markedly attenuated by blocking the cardiac sympathetic nerve (range: −9 to +3 bpm, p mechanical stimulation increased, or decreased the frequency of sympathetic nerve activity in parallel with HR (r = 0.77, p = 0.0004). Furthermore, the changes in sympathetic nerve activity were negatively correlated with its tonic level (r = −0.62, p = 0.0066). These results suggest that cardiac sympathetic nerve activity regulates HR responses to muscle mechanical pressure stimulation and the direction of HR

  9. 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.

  10. 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

  11. Onion artificial muscles

    Science.gov (United States)

    Chen, Chien-Chun; Shih, Wen-Pin; Chang, Pei-Zen; Lai, Hsi-Mei; Chang, Shing-Yun; Huang, Pin-Chun; Jeng, Huai-An

    2015-05-01

    Artificial muscles are soft actuators with the capability of either bending or contraction/elongation subjected to external stimulation. However, there are currently no artificial muscles that can accomplish these actions simultaneously. We found that the single layered, latticed microstructure of onion epidermal cells after acid treatment became elastic and could simultaneously stretch and bend when an electric field was applied. By modulating the magnitude of the voltage, the artificial muscle made of onion epidermal cells would deflect in opposing directions while either contracting or elongating. At voltages of 0-50 V, the artificial muscle elongated and had a maximum deflection of -30 μm; at voltages of 50-1000 V, the artificial muscle contracted and deflected 1.0 mm. The maximum force response is 20 μN at 1000 V.

  12. 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;

    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....

  13. [Rehabilitation of facial paralysis using autogenous fascia lata graft. Stable results over time].

    Science.gov (United States)

    Graillon, N; Colson, T; Bardot, J

    2015-10-01

    Dynamic facial reanimation with free muscle or nerve transfers represents the mainstay of facial paralysis treatments particularly for perioral area and smile. These techniques are not always feasible, in such cases we perform a perioral suspension with fascia lata graft. However many teams blame this technique for short-term recurrence of the deformity. We describe in this paper details of our surgical technique, to improve the aesthetic result and stability over time, and the results and complications encountered. Fascia lata graft was sutured beyond the midline to the contralateral healthy lips, after tunneling through upper and lower orbicularis oris. Fascia lata graft was then tunneled through the buccal fat pad, then under the zygomatic arch to the temporal region, where the temporal aponeurosis was incised to make way for the fascia lata graft, which was fixed to the outer face of the temporal aponeurosis, applying slight overcorrection to the oral commissure. From 2003 to 2012, we performed this procedure on 8 patients. Results showed an immediate aesthetic improvement, stable over time. Perioral suspension with fascia lata graft is a surgical alternative when dynamic reanimation is not feasible.

  14. Ultrasonographic Evaluation of Peripheral Nerves.

    Science.gov (United States)

    Ali, Zarina S; Pisapia, Jared M; Ma, Tracy S; Zager, Eric L; Heuer, Gregory G; Khoury, Viviane

    2016-01-01

    There are a variety of imaging modalities for evaluation of peripheral nerves. Of these, ultrasonography (US) is often underused. There are several advantages of this imaging modality, including its cost-effectiveness, time-efficient assessment of long segments of peripheral nerves, ability to perform dynamic maneuvers, lack of contraindications, portability, and noninvasiveness. It can provide diagnostic information that cannot be obtained by electrophysiologic or, in some cases, magnetic resonance imaging studies. Ideally, the neurosurgeon can use US as a diagnostic adjunct in the preoperative assessment of a patient with traumatic, neoplastic, infective, or compressive nerve injury. Perhaps its most unique use is in intraoperative surgical planning. In this article, a brief description of normal US nerve anatomy is presented followed by a description of the US appearance of peripheral nerve disease caused by trauma, tumor, infection, and entrapment.

  15. Peripheral nerve lengthening as a regenerative strategy

    Institute of Scientific and Technical Information of China (English)

    Kenneth M.Vaz; Justin M.Brown; Sameer B.Shah

    2014-01-01

    Peripheral nerve injury impairs motor, sensory, and autonomic function, incurring substantial ifnancial costs and diminished quality of life. For large nerve gaps, proximal lesions, or chronic nerve injury, the prognosis for recovery is particularly poor, even with autografts, the current gold standard for treating small to moderate nerve gaps. In vivo elongation of intact proximal stumps towards the injured distal stumps of severed peripheral nerves may offer a promising new strategy to treat nerve injury. This review describes several nerve lengthening strategies, in-cluding a novel internal ifxator device that enables rapid and distal reconnection of proximal and distal nerve stumps.

  16. Coaxial electrospinning of P(LLA-CL)/heparin biodegradable polymer nanofibers: potential vascular graft for substitution of femoral artery.

    Science.gov (United States)

    Zhai, Wei; Qiu, Li-Jun; Mo, Xiu-Mei; Wang, Sheng; Xu, Yun-Fei; Peng, Bo; Liu, Min; Huang, Jun-Hua; Wang, Guang-Chun; Zheng, Jun-Hua

    2013-06-07

    Electrospinning is one of the most simple and effective methods to prepare polymer fibers with the diameters ranging from nanometer to several micrometers. Poly(L-lactide)-co-poly (ɛ-caprolactone) (P(LLA-CL)) fibers and P(LLA-CL)/heparin coaxial composite fibers herein were successfully prepared by single electrospinning and coaxial electrospinning, respectively. The prepared endothelialized P(LLA-CL) and P(LLA-CL)/heparin vascular grafts were used in the Beagle dogs experiment to evaluate the feasibility of thus made different scaffolds for substitution of dog femoral artery in early period, medium term, and long term, meanwhile the pure P(LLA-CL) vascular graft was used as the control group during all the experiments. The animal model was established by using the graft materials to anastomose both femoral arteries of dogs. The vascular grafts patency rates (i.e., the unobstructed capacity of blood vessel) were detected by color Doppler flow imaging technology and digital subtraction angiography. To observe the histological morphology at different periods, the vascular grafts were removed after 7, 14, and 30 days, and the corresponding histological changes were evaluated by hematoxylin and eosin staining. The experimental results show that in the early period, the patency rates of pure P(LLA-CL) graft, endothelial P(LLA-CL) graft, and P(LLA-CL)/heparin graft were 75%, 75%, and 100%, respectively; in the medium term, the patency rates of pure P(LLA-CL) graft and endothelial P(LLA-CL) graft were 25%, whereas that of P(LLA-CL)/heparin graft was 50%; the patency rates of pure P(LLA-CL) graft and endothelial P(LLA-CL) graft were down to 0%, whereas the patency rate of P(LLA-CL)/heparin graft was 25% in the long term. This preliminary study has demonstrated that P(LLA-CL)/heparin coaxial composite fiber maybe a reliable artificial graft for the replacement of femoral artery. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.

  17. Biomimetic approaches to bionic touch through a peripheral nerve interface.

    Science.gov (United States)

    Saal, Hannes P; Bensmaia, Sliman J

    2015-12-01

    State-of-the-art prosthetic hands nearly match the dexterity of the human hand, and sophisticated approaches have been developed to control them intuitively. However, grasping and dexterously manipulating objects relies heavily on the sense of touch, without which we would struggle to perform even the most basic activities of daily living. Despite the importance of touch, not only in motor control but also in affective communication and embodiment, the restoration of touch through bionic hands is still in its infancy, a shortcoming that severely limits their effectiveness. Here, we focus on approaches to restore the sense of touch through an electrical interface with the peripheral nerve. First, we describe devices that can be chronically implanted in the nerve to electrically activate nerve fibers. Second, we discuss how these interfaces have been used to convey basic somatosensory feedback. Third, we review what is known about how the somatosensory nerve encodes information about grasped objects in intact limbs and discuss how these natural neural codes can be exploited to convey artificial tactile feedback. Finally, we offer a blueprint for how these codes could be implemented in a neuroprosthetic device to deliver rich, natural, and versatile tactile sensations.

  18. Exposure to Nerve Growth Factor Worsens Nephrotoxic Effect Induced by Cyclosporine A in HK-2 Cells

    Science.gov (United States)

    Lofaro, Danilo; Toteda, Giuseppina; Lupinacci, Simona; Leone, Francesca; Gigliotti, Paolo; Papalia, Teresa; Bonofiglio, Renzo

    2013-01-01

    Nerve growth factor is a neurotrophin that promotes cell growth, differentiation, survival and death through two different receptors: TrkANTR and p75NTR. Nerve growth factor serum concentrations increase during many inflammatory and autoimmune diseases, glomerulonephritis, chronic kidney disease, end-stage renal disease and, particularly, in renal transplant. Considering that nerve growth factor exerts beneficial effects in the treatment of major central and peripheral neurodegenerative diseases, skin and corneal ulcers, we asked whether nerve growth factor could also exert a role in Cyclosporine A-induced graft nephrotoxicity. Our hypothesis was raised from basic evidence indicating that Cyclosporine A-inhibition of calcineurin-NFAT pathway increases nerve growth factor expression levels. Therefore, we investigated the involvement of nerve growth factor and its receptors in the damage exerted by Cyclosporine A in tubular renal cells, HK-2. Our results showed that in HK-2 cells combined treatment with Cyclosporine A + nerve growth factor induced a significant reduction in cell vitality concomitant with a down-regulation of Cyclin D1 and up-regulation of p21 levels respect to cells treated with Cyclosporine A alone. Moreover functional experiments showed that the co-treatment significantly up-regulated human p21promoter activity by involvement of the Sp1 transcription factor, whose nuclear content was negatively regulated by activated NFATc1. In addition we observed that the combined exposure to Cyclosporine A + nerve growth factor promoted an up-regulation of p75 NTR and its target genes, p53 and BAD leading to the activation of intrinsic apoptosis. Finally, the chemical inhibition of p75NTR down-regulated the intrinsic apoptotic signal. We describe two new mechanisms by which nerve growth factor promotes growth arrest and apoptosis in tubular renal cells exposed to Cyclosporine A. PMID:24244623

  19. Exposure to nerve growth factor worsens nephrotoxic effect induced by Cyclosporine A in HK-2 cells.

    Directory of Open Access Journals (Sweden)

    Donatella Vizza

    Full Text Available Nerve growth factor is a neurotrophin that promotes cell growth, differentiation, survival and death through two different receptors: TrkA(NTR and p75(NTR. Nerve growth factor serum concentrations increase during many inflammatory and autoimmune diseases, glomerulonephritis, chronic kidney disease, end-stage renal disease and, particularly, in renal transplant. Considering that nerve growth factor exerts beneficial effects in the treatment of major central and peripheral neurodegenerative diseases, skin and corneal ulcers, we asked whether nerve growth factor could also exert a role in Cyclosporine A-induced graft nephrotoxicity. Our hypothesis was raised from basic evidence indicating that Cyclosporine A-inhibition of calcineurin-NFAT pathway increases nerve growth factor expression levels. Therefore, we investigated the involvement of nerve growth factor and its receptors in the damage exerted by Cyclosporine A in tubular renal cells, HK-2. Our results showed that in HK-2 cells combined treatment with Cyclosporine A + nerve growth factor induced a significant reduction in cell vitality concomitant with a down-regulation of Cyclin D1 and up-regulation of p21 levels respect to cells treated with Cyclosporine A alone. Moreover functional experiments showed that the co-treatment significantly up-regulated human p21promoter activity by involvement of the Sp1 transcription factor, whose nuclear content was negatively regulated by activated NFATc1. In addition we observed that the combined exposure to Cyclosporine A + nerve growth factor promoted an up-regulation of p75 (NTR and its target genes, p53 and BAD leading to the activation of intrinsic apoptosis. Finally, the chemical inhibition of p75(NTR down-regulated the intrinsic apoptotic signal. We describe two new mechanisms by which nerve growth factor promotes growth arrest and apoptosis in tubular renal cells exposed to Cyclosporine A.

  20. 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.

  1. Nanofibrous nerve conduit-enhanced peripheral nerve regeneration.

    Science.gov (United States)

    Jiang, Xu; Mi, Ruifa; Hoke, Ahmet; Chew, Sing Yian

    2014-05-01

    Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (ε-caprolactone) (PCL) microfibers (981 ± 83 nm, Microfiber) or nanofibers (251 ± 32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p regeneration. These results could provide useful insights for future nerve guide designs.

  2. 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.

  3. Artificial intelligence in medicine.

    Science.gov (United States)

    Ramesh, A. N.; Kambhampati, C.; Monson, J. R. T.; Drew, P. J.

    2004-01-01

    INTRODUCTION: Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. METHODS: Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of different artificial intelligent techniques is presented in this paper along with the review of important clinical applications. RESULTS: The proficiency of artificial intelligent techniques has been explored in almost every field of medicine. Artificial neural network was the most commonly used analytical tool whilst other artificial intelligent techniques such as fuzzy expert systems, evolutionary computation and hybrid intelligent systems have all been used in different clinical settings. DISCUSSION: Artificial intelligence techniques have the potential to be applied in almost every field of medicine. There is need for further clinical trials which are appropriately designed before these emergent techniques find application in the real clinical setting. PMID:15333167

  4. Release of relaxin-like gonad-stimulating substance from starfish radial nerves by lonomycin.

    Science.gov (United States)

    Mita, Masatoshi

    2013-07-01

    In starfish, the peptide hormone gonad-stimulating substance (GSS) secreted from nervous tissue stimulates oocyte maturation to induce 1-methyladenine (1-MeAde) production by ovarian follicle cells. Recently, GSS was purified from radial nerves of the starfish Asterina pectinifera and identified as a relaxin-like peptide. This study examines the mechanism of GSS secretion from radial nerves. When radial nerves isolated from A. pectinifera were incubated in artificial seawater containing ionomycin as a calcium ionophore, GSS release increased in a dose-dependent manner; 50% activity of GSS release was obtained with approximately 10 µM ionomycin. Another calcium ionophore, A23187, also stimulated GSS release from radial nerves. In contrast, membrane permeable cyclic AMP and cyclic GMP analogs failed to induce GSS release. These results suggest that GSS secretion is induced by intracellular Ca(2+) as a second messenger.

  5. Gait analysis in rats with peripheral nerve injury.

    Science.gov (United States)

    Yu, P; Matloub, H S; Sanger, J R; Narini, P

    2001-02-01

    Rats are commonly used to study peripheral nerve repair and grafting. The traditional footprint method to assess functional recovery is messy, indirect, and not useful when contractures develop in the animal model. The aim of the present study was to establish an accurate, reproducible, but simple, method to assess dynamic limb function. The basic quantitative aspects of a normal gait were characterized from 59 recorded walks in 23 rats. The video was digitized and analyzed frame by frame on a personal computer. Seven parameters of the gait were assessed: (1) walking speed; (2) stance phase, swing phase and right to left stance/swing ratio; (3) step length and step length ratio; (4) ankle angles at terminal stance and midswing; (5) tail height; (6) midline deviation; and (7) tail deviation. These gait parameters were then applied to groups of animals with sciatic (group S), tibial (group T), and peroneal (group P) nerve injuries. A discriminant analysis was performed to analyze each parameter and to compute a functional score. We found that the video gait analysis was superior to the footprint method and believe it will be very useful in future studies on peripheral nerve injury.

  6. Correction of intrinsic penile chordee with a ventral penile graft of fascia lata.

    Science.gov (United States)

    Thomas, R; Palomar, J M; Evans, B B; Lewis, R W

    1988-07-01

    Chordee is an abnormal curvature of the penis detected on erection. Congenital or primary curvature of the penis without hypospadias is, however, rare. There are two kinds of primary curvatures; those associated with a normal corpus spongiosum and those with a hypoplastic spongiosum. Secondary curvatures associated with Peyronie's disease or periurethral fibrosis associated with urethral stricture are more common in adults. Four nonhuman primates had successful correction of artificially induced chordee with a graft of fascia lata.

  7. Sensory nerve conduction studies in neuralgic amyotrophy.

    Science.gov (United States)

    van Alfen, Nens; Huisman, Willem J; Overeem, S; van Engelen, B G M; Zwarts, M J

    2009-11-01

    Neuralgic amyotrophy is a painful, episodic peripheral nerve disorder localized to the brachial plexus. Sensory symptoms occur in 80% of the patients. We assessed the frequency of abnormalities in sensory nerve conduction studies of the lateral and medial antebrachial cutaneous, radial sensory, median sensory, and ulnar sensory nerves in 112 patients. Sensory nerve conduction studies showed abnormalities in nerves, even when the nerve was clinically affected. The lateral and medial antebrachial cutaneous nerves were most often abnormal, in 15% and 17% of nerves. No correlation with the presence or localization of clinical deficits was found. Brachial plexus sensory nerve conduction studies seem to be of little diagnostic value in neuralgic amyotrophy. Our findings also indicate that some sensory lesions may be in the nerve roots instead of the plexus. An examination of normal sensory nerve conduction studies does not preclude neuralgic amyotrophy as a diagnosis.

  8. [Paralysis of the femoral nerve complicating ilio-psoas hemorrhage after iliac bone transplantation (author's transl)].

    Science.gov (United States)

    Mestdagh, H

    1982-03-11

    The author reported an unusual complication of iliac bone transplantation for grafting of a tibial pseudarthrosis. In a patient having anticoagulant therapy, a large iliac haematoma developed in the donor site and extended deep to the iliacus muscle and through the osteomuscular gap into the retroperitoneal space. Moreover it spread downwards and entrapped the femoral nerve as it lies behind the iliac fascia, above the inguinal ligament. Both a paralytic ileus and a femoral nerve injury commanded surgical exploration through an oblique iliac approach; emptying of the clotted haematoma, section of the inguinal ligament and liberation of the femoral nerve enable to avoid definitive sequelae to the quadriceps but the time required is varying: three years after the accident, recovery is not complete in the operated patient probably owing to delayed surgery (three weeks).

  9. External iliac artery thrombus masquerading as sciatic nerve palsy in anterior column fracture of the acetabulum

    Directory of Open Access Journals (Sweden)

    Narender Kumar Magu

    2015-01-01

    Full Text Available We report a case of ischemic neuropathy of the sciatic nerve in a patient with an anterior column fracture of the acetabulum operated by ilioinguinal approach. It resulted from occlusion of the blood supply to the sciatic nerve. There were no signs of a vascular insult until ischemic changes ensued on the 6 th postoperative day on the lateral part of great toe. The patient underwent crossover femoro-femoral bypass grafting and there was a complete reversal of the ischemic changes at 6 months. The sciatic nerve palsy continued to recover until the end of 1 year; by which time the only deficit was a Grade 4 power in the extensor hallucis longus (EHL and the extensor digitorum longus (EDL. There was no further recovery at 2 years followup.

  10. 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.

  11. 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

  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. Dynamics of bone graft healing around implants

    Directory of Open Access Journals (Sweden)

    Narayan Venkataraman

    2015-01-01

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

  14. Artificial Neural Networks

    OpenAIRE

    Chung-Ming Kuan

    2006-01-01

    Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems. In this entry, we introduce ANN using familiar econometric terminology and provide an overview of ANN modeling approach and its implementation methods.

  15. Introduction to artificial intelligence

    Science.gov (United States)

    Cheeseman, P.; Gevarter, W.

    1986-01-01

    This paper presents an introductory view of Artificial Intelligence (AI). In addition to defining AI, it discusses the foundations on which it rests, research in the field, and current and potential applications.

  16. 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.)

  17. EXPRESSION OF CALCITONIN GENE-RELATED PEPTIDE IN FACIAL NERVE OF HEMIFACIAL SPASM

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective To study the immunoreactivity of Calcitonin gene-related peptide (CGRP) in the facial nerve when Hemifacial Spasm is occurring. Methods The electrophysiological technique was used to explore abnormal muscle response (AMR) which was characteristic of Hemifacial Spasm.The animal models of Hemifacial Spasm in New Zealand white rabbits were established by compressing the main trunk of artificial demyelinated facial nerve with the temporal superficial artery. At 6 weeks after surgery, the facial nerves were taken from the experimental group and control one, the immunohistochemistry for CGRP using polyclonal antibody with ABC kit was performed in the facial nerves; at the same time, the observation for the facial nerves of light and transmission electron microscope was performed. Results The facial nerve demyelinated and the axons retrogressively changed, CGRP immunoreactive positive fibers were significantly detected in experimental groups; whereas this phenomenon was not found in control group. Conclusion CGRP can nutrien the injured facial nerve and plays an important role in the pathogenesis of Hemifacial Spasm.

  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. Physics of Artificial Gravity

    Science.gov (United States)

    Bukley, Angie; Paloski, William; Clement, Gilles

    2006-01-01

    This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented.

  20. Radiation-induced grafting of diallyldimethylammonium chloride onto acrylic acid grafted polyethylene

    Science.gov (United States)

    Francis, Sanju; Dhanawade, B. R.; Mitra, D.; Varshney, Lalit; Sabharwal, Sunil

    2009-01-01

    Diallyldimethylammonium chloride (DADMAC) was grafted onto polyethylene (PE) films by a double grafting procedure. The PE film was initially modified by grafting acrylic acid (AA), through a mutual irradiation method. AA-g-PE film, thus obtained was subjected to subsequent radiation grafting reaction of DADMAC, to give a DADMAC-g-AA-g-PE film having a comb-type structure. The influence of different conditions, such as the extent of AA grafting, DADMAC concentration, absorbed dose and dose rate, on the grafting yield of DADMAC was investigated. A maximum DADMAC grafting of 30% was achieved. The equilibrium degree of swelling (EDS) of the grafted films were gravimetrically determined. TGA and FT-IR techniques were employed to characterize the grafted PE films.

  1. Radiation-induced grafting of diallyldimethylammonium chloride onto acrylic acid grafted polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Sanju [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)], E-mail: sanju@barc.gov.in; Dhanawade, B.R.; Mitra, D.; Varshney, Lalit; Sabharwal, Sunil [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2009-01-15

    Diallyldimethylammonium chloride (DADMAC) was grafted onto polyethylene (PE) films by a double grafting procedure. The PE film was initially modified by grafting acrylic acid (AA), through a mutual irradiation method. AA-g-PE film, thus obtained was subjected to subsequent radiation grafting reaction of DADMAC, to give a DADMAC-g-AA-g-PE film having a comb-type structure. The influence of different conditions, such as the extent of AA grafting, DADMAC concentration, absorbed dose and dose rate, on the grafting yield of DADMAC was investigated. A maximum DADMAC grafting of 30% was achieved. The equilibrium degree of swelling (EDS) of the grafted films were gravimetrically determined. TGA and FT-IR techniques were employed to characterize the grafted PE films.

  2. Heidegger and artificial intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, G.

    1987-01-01

    The discipline of Artificial Intelligence, in its quest for machine intelligence, showed great promise as long as its areas of application were limited to problems of a scientific and situation neutral nature. The attempts to move beyond these problems to a full simulation of man's intelligence has faltered and slowed it progress, largely because of the inability of Artificial Intelligence to deal with human characteristic, such as feelings, goals, and desires. This dissertation takes the position that an impasse has resulted because Artificial Intelligence has never been properly defined as a science: its objects and methods have never been identified. The following study undertakes to provide such a definition, i.e., the required ground for Artificial Intelligence. The procedure and methods employed in this study are based on Heidegger's philosophy and techniques of analysis as developed in Being and Time. Results of this study show that both the discipline of Artificial Intelligence and the concerns of Heidegger in Being and Time have the same object; fundamental ontology. The application of Heidegger's conclusions concerning fundamental ontology unites the various aspects of Artificial Intelligence and provides the articulation which shows the parts of this discipline and how they are related.

  3. Solitary fibrous tumour of the vagus nerve.

    Science.gov (United States)

    Scholsem, Martin; Scholtes, Felix

    2012-04-01

    We describe the complete removal of a foramen magnum solitary fibrous tumour in a 36-year-old woman. It originated on a caudal vagus nerve rootlet, classically described as the 'cranial' accessory nerve root. This ninth case of immunohistologically confirmed cranial or spinal nerve SFT is the first of the vagus nerve.

  4. 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.

  5. GRP nerves in pig antrum

    DEFF Research Database (Denmark)

    Holst, J J; Poulsen, Steen Seier

    1987-01-01

    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....

  6. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2015-10-01

    human amnion membrane and periosteal autograft on tendon healing: experimental study in rabbits. J Hand Surg Eur Vol 2010;35:262e8. 674 N.G. Fairbairn...SE, Hunter DA. Functional evaluation of complete sciatic, peroneal, and posterior tibial nerve lesions in the rat. Plast Reconstr Surg. 1989;83:129...complete sciatic, peroneal, and posterior tibial nerve lesions in the rat. Plastic and reconstructive surgery. 1989 Jan;83(1):129-38. PubMed PMID: 2909054

  7. [Autologous fat grafting in children].

    Science.gov (United States)

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

    2016-10-01

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

  8. Hybrid Graft Anterior Cruciate Ligament Reconstruction: A Predictable Graft for Knee Stabilization.

    Science.gov (United States)

    Alvarez-Pinzon, Andres M; Barksdale, Leticia; Krill, Michael K; Leo, Brian M

    2015-06-01

    Trauma to the anterior cruciate ligament (ACL) is a season-ending injury and involves months of activity modification and rehabilitation. The annual incidence of ACL tears in the United States is approximately 200,000, which allows for a broad range of individualized treatment options. Various surgical techniques, including transtibial and independent tunnel drilling, allograft and autograft tissue, and various implants, have been described in the literature. This article describes the indications and technique for a hybrid soft tissue graft for ACL reconstruction. Autologous grafts eliminate the risk of disease transmission and have recently been shown to have a lower rerupture rate, particularly in younger, active patients; however, the harvesting of autologous hamstring grafts carries a risk of donor-site morbidity, iatrogenic injury of the graft, and inadequate graft size. In contrast to a traditional autologous soft tissue graft, the hybrid graft allows for graft size customization for a desired reconstruction, especially in cases where autograft hamstrings may be iatrogenically damaged or of inadequate size when harvested. The goal of a hybrid graft ACL reconstruction is to provide a favorable-sized graft with clinical outcomes comparable with autologous soft tissue grafts. In contrast to a traditional autologous soft tissue graft, this technique provides another option in the event of unforeseen deficiencies or complications associated with harvesting and preparation of the autologous gracilis and semitendinosis soft tissue graft.

  9. CROSSING ANASTOMOSIS OF NERVE BUNDLES NEAR INNERVATED ORGANS TO TREAT IRREPARABLE NERVE INJURIES

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To study the therapeutical effects of crossing anastomosis of nerve on the peripheral and central nerve injuries.Methods Twelve kinds of central and peripheral nerve disorders and their complications were treated with 11 kinds of crossing anastomosis of nerve bundles near the innervated organs. After nerve injury and repair, somatosensory evoked potentials (SEPs) and horseradish peroxidase (HRP) retrograde tracing studies were used to investigate the rabbit's nerve function and morphology.Results The ulcers of all patients healed. Sensation, voluntary movement, and joint function recovered. Four weeks after the anastomosis of distal stump of radialis superficialis nerve and median nerve, pain sensation regained and SEPs appeared. HRP retrograde tracing studies demonstrated sensory nerve ending of medial nerve formed new connection with the body of neuron.Conclusion Crossing anastomosis of nerve is an effective method to treat peripheral and central nerve injuries.

  10. Clinical use of nerve conduits in peripheral-nerve repair : Review of the literature

    NARCIS (Netherlands)

    Meek, MF; Coert, JH

    2002-01-01

    The use of nerve conduits has evolved from a previous experimental idea to a clinical reality over the last ten years. An overview of the literature on the clinical use of nerve conduits in peripheral-nerve repair is presented.

  11. Twist and its effect on ACL graft forces

    NARCIS (Netherlands)

    Arnold, MP; Blankevoort, L; ten Ham, A; Verdonschot, N; van Kampen, A

    2004-01-01

    Graft tension is a controversial topic in anterior cruciate ligament (ACL) surgery. Evidence suggests a narrow range of graft tensions, which allow the graft to remodel to a stable and mature neoligament. In previous cadaver experiments, we showed that twisting the graft could modulate the graft for

  12. Twist and its effect on ACL graft forces.

    NARCIS (Netherlands)

    Arnold, M.P.; Blankevoort, L.; Ham, A. ten; Verdonschot, N.J.J.; Kampen, A. van

    2004-01-01

    Graft tension is a controversial topic in anterior cruciate ligament (ACL) surgery. Evidence suggests a narrow range of graft tensions, which allow the graft to remodel to a stable and mature neoligament. In previous cadaver experiments, we showed that twisting the graft could modulate the graft for

  13. 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.

  14. 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

  15. Artificial vision workbench.

    Science.gov (United States)

    Frenger, P

    1997-01-01

    Machine vision is an important component of medical systems engineering. Inexpensive miniature solid state cameras are now available. This paper describes how these devices can be used as artificial retinas, to take snapshots and moving pictures in monochrome or color. Used in pairs, they produce a stereoscopic field of vision and enable depth perception. Macular and peripheral vision can be simulated electronically. This paper also presents the author's design of an artificial orbit for this synthetic eye. The orbit supports the eye, protects it, and provides attachment points for the ocular motion control system. Convergence and image fusion can be produced, and saccades simulated, along with the other ocular motions. The use of lenses, filters, irises and focusing mechanisms are also discussed. Typical camera-computer interfaces are described, including the use of "frame grabbers" and analog-to-digital image conversion. Software programs for eye positioning, image manipulation, feature extraction and object recognition are discussed, including the application of artificial neural networks.

  16. Artificial intelligence in nanotechnology.

    Science.gov (United States)

    Sacha, G M; Varona, P

    2013-11-15

    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.

  17. Artificial muscles on heat

    Science.gov (United States)

    McKay, Thomas G.; Shin, Dong Ki; Percy, Steven; Knight, Chris; McGarry, Scott; Anderson, Iain A.

    2014-03-01

    Many devices and processes produce low grade waste heat. Some of these include combustion engines, electrical circuits, biological processes and industrial processes. To harvest this heat energy thermoelectric devices, using the Seebeck effect, are commonly used. However, these devices have limitations in efficiency, and usable voltage. This paper investigates the viability of a Stirling engine coupled to an artificial muscle energy harvester to efficiently convert heat energy into electrical energy. The results present the testing of the prototype generator which produced 200 μW when operating at 75°C. Pathways for improved performance are discussed which include optimising the electronic control of the artificial muscle, adjusting the mechanical properties of the artificial muscle to work optimally with the remainder of the system, good sealing, and tuning the resonance of the displacer to minimise the power required to drive it.

  18. Artificial intelligence in nanotechnology

    Science.gov (United States)

    Sacha, G. M.; Varona, P.

    2013-11-01

    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.

  19. Artificial organ engineering

    CERN Document Server

    Annesini, Maria Cristina; Piemonte, Vincenzo; Turchetti, Luca

    2017-01-01

    Artificial organs may be considered as small-scale process plants, in which heat, mass and momentum transfer operations and, possibly, chemical transformations are carried out. This book proposes a novel analysis of artificial organs based on the typical bottom-up approach used in process engineering. Starting from a description of the fundamental physico-chemical phenomena involved in the process, the whole system is rebuilt as an interconnected ensemble of elemental unit operations. Each artificial organ is presented with a short introduction provided by expert clinicians. Devices commonly used in clinical practice are reviewed and their performance is assessed and compared by using a mathematical model based approach. Whilst mathematical modelling is a fundamental tool for quantitative descriptions of clinical devices, models are kept simple to remain focused on the essential features of each process. Postgraduate students and researchers in the field of chemical and biomedical engineering will find that t...

  20. CHEMICAL MORPHOLOGY IN GRAFTING ACRYLAMIDE TO POLYETHYLENE

    Institute of Scientific and Technical Information of China (English)

    S. Termnak; K. Sintasanai; T. Amomsakchai; T. Nipithakul; D. Triampo

    2008-01-01

    The scanning force microscopy (SFM)/chemical force microscopy (CFM) were used to study the growth of grafted polyacrylamide (PAM) chains onto polyethylene (PE)-film with varying grafting time. Results from the CFM reveal reduced interaction between the probe and areas with grafted-PAM on the surface. The topography and the friction trace-minus-retrace (TMR) images are complementary to one another resulting from the reduced interaction of the probe that has specificity to chemical domains.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Bayesian artificial intelligence

    CERN Document Server

    Korb, Kevin B

    2003-01-01

    As the power of Bayesian techniques has become more fully realized, the field of artificial intelligence has embraced Bayesian methodology and integrated it to the point where an introduction to Bayesian techniques is now a core course in many computer science programs. Unlike other books on the subject, Bayesian Artificial Intelligence keeps mathematical detail to a minimum and covers a broad range of topics. The authors integrate all of Bayesian net technology and learning Bayesian net technology and apply them both to knowledge engineering. They emphasize understanding and intuition but also provide the algorithms and technical background needed for applications. Software, exercises, and solutions are available on the authors' website.

  6. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    Although spatial structures can play a crucial role in chemical systems and can drastically alter the outcome of reactions, the traditional framework of artificial chemistry is a well-stirred tank reactor with no spatial representation in mind. Advanced method development in physical chemistry has...... 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...

  7. General artificial neuron

    Science.gov (United States)

    Degeratu, Vasile; Schiopu, Paul; Degeratu, Stefania

    2007-05-01

    In this paper the authors present a model of artificial neuron named the general artificial neuron. Depending on application this neuron can change self number of inputs, the type of inputs (from excitatory in inhibitory or vice versa), the synaptic weights, the threshold, the type of intensifying functions. It is achieved into optoelectronic technology. Also, into optoelectronic technology a model of general McCulloch-Pitts neuron is showed. The advantages of these neurons are very high because we have to solve different applications with the same neural network, achieved from these neurons, named general neural network.

  8. What Protects Certain Nerves from Stretch Injury?

    Science.gov (United States)

    Schraut, Nicholas B; Walton, Sharon; Bou Monsef, Jad; Shott, Susan; Serici, Anthony; Soulii, Lioubov; Amirouche, Farid; Gonzalez, Mark H; Kerns, James M

    2016-01-01

    The human tibial nerves is less prone to injury following joint arthroplasty compared with the peroneal nerves. Besides the anatomical distribution, other features may confer protection from stretch injury. We therefore examined the size, shape and connective tissue distribution for the two nerves. The tibial and peroneal nerves from each side of nine fresh human cadavers we reharvested mid-thigh. Proximal segments manually stretched 20%-25% were fixed in aldehyde, while the adjacent distal segments were fixed in their natural length. Paraffin sections stained by Masson's trichrome method for connective tissue were examined by light microscopy. Tibial nerves had 2X more fascicles compared with the peroneal, but the axonal content appeared similar. Analysis showed that neither nerve had a significant reduction in cross sectional area of the fascicles following stretch. However, fascicles from stretched tibial nerves become significantly more oval compared with those from unstretched controls and peroneal nerves. Tibial nerves had a greater proportion that was extrafascicular tissue (50-55%) compared with peroneal nerves (38%-42%). This epineurium was typically adipose tissue. Perineurial thickness in both nerves was directly related to fascicular size. Tibial nerves have several unique histological features associated with size, shape and tissue composition compared with the peroneal nerve. We suggest that more fascicles with their tightly bound perineurium and more robust epineurium afford protection against stretch injury. Mechanical studies should clarify how size and shape contribute to nerve protection and/or neurapraxia.

  9. 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.

  10. Masseteric-facial nerve transposition for reanimation of the smile in incomplete facial paralysis.

    Science.gov (United States)

    Hontanilla, Bernardo; Marre, Diego

    2015-12-01

    Incomplete facial paralysis occurs in about a third of patients with Bell's palsy. Although their faces are symmetrical at rest, when they smile they have varying degrees of disfigurement. Currently, cross-face nerve grafting is one of the most useful techniques for reanimation. Transfer of the masseteric nerve, although widely used for complete paralysis, has not to our knowledge been reported for incomplete palsy. Between December 2008 and November 2013, we reanimated the faces of 9 patients (2 men and 7 women) with incomplete unilateral facial paralysis with transposition of the masseteric nerve. Sex, age at operation, cause of paralysis, duration of denervation, recipient nerves used, and duration of follow-up were recorded. Commissural excursion, velocity, and patients' satisfaction were evaluated with the FACIAL CLIMA and a questionnaire, respectively. The mean (SD) age at operation was 39 (±6) years and the duration of denervation was 29 (±19) months. There were no complications that required further intervention. Duration of follow-up ranged from 6-26 months. FACIAL CLIMA showed improvement in both commissural excursion and velocity of more than two thirds in 6 patients, more than one half in 2 patients and less than one half in one. Qualitative evaluation showed a slight or pronounced improvement in 7/9 patients. The masseteric nerve is a reliable alternative for reanimation of the smile in patients with incomplete facial paralysis. Its main advantages include its consistent anatomy, a one-stage operation, and low morbidity at the donor site.

  11. 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.

  12. Artificial phrenoesophageal ligament. An experimental study in dogs.

    Science.gov (United States)

    Sader, A A; Dantas, R O; Campos, A D; Evora, P R B

    2016-01-01

    This report deals with the preparation of a 'true' artificial phrenoesophageal ligament aimed at restoring effective anchoring of the esophagus to the diaphragm, keeping the esophagogastric sphincter in the abdomen. A total of 24 mongrel dogs were assigned to four groups: (i) Group I (n = 4): the esophageal diaphragm hiatus left wide open; (ii) Group II (n = 8): the anterolateral esophagus walls were attached to the diaphragm by the artificial ligament and the esophageal hiatus was left wide opened; (iii) Group III (n = 5): in addition to the use of the artificial ligament, the esophageal hiatus was narrowed with two retroesophageal stitches; (iv) Group IV (n = 7): the only procedure was the esophageal hiatus narrowing with two retroesophageal stitches. The phrenoesophagogastric connections were released, sparing the vagus nerves. Five animals of groups III and IV, which did not develop hiatal hernia, were submitted to esophageal manometry immediately before and 15 days after surgery. In group I, all animals developed huge sliding hiatal hernias. In group II, two dogs (25%) had a paraesophageal hernia between the two parts of the artificial ligament. In group III, neither sliding hiatal hernia nor paraesophageal hernia occurred. In group IV, two animals (28.6%) developed sliding esophageal hiatus hernia. Regarding esophageal manometry, postoperative significant difference between groups III and IV (P = 0.008) was observed. Thus, the artificial phrenoesophageal ligament maintained the esophagus firmly attached to the diaphragm in all animals and the esophagogastric sphincter pressure was significantly higher in this group.

  13. Cardiac autonomic nerve distribution and arrhythmia

    Institute of Scientific and Technical Information of China (English)

    Quan Liu; Dongmei Chen; Yonggang Wang; Xin Zhao; Yang Zheng

    2012-01-01

    OBJECTIVE: To analyze the distribution characteristics of cardiac autonomic nerves and to explore the correlation between cardiac autonomic nerve distribution and arrhythmia.DATA RETRIEVAL: A computer-based retrieval was performed for papers examining the distribution of cardiac autonomic nerves, using "heart, autonomic nerve, sympathetic nerve, vagus nerve, nerve distribution, rhythm and atrial fibrillation" as the key words.SELECTION CRITERIA: A total of 165 studies examining the distribution of cardiac autonomic nerve were screened, and 46 of them were eventually included.MAIN OUTCOME MEASURES: The distribution and characteristics of cardiac autonomic nerves were observed, and immunohistochemical staining was applied to determine the levels of tyrosine hydroxylase and acetylcholine transferase (main markers of cardiac autonomic nerve distribution). In addition, the correlation between cardiac autonomic nerve distribution and cardiac arrhythmia was investigated.RESULTS: Cardiac autonomic nerves were reported to exhibit a disordered distribution in different sites, mainly at the surface of the cardiac atrium and pulmonary vein, forming a ganglia plexus. The distribution of the pulmonary vein autonomic nerve was prominent at the proximal end rather than the distal end, at the upper left rather than the lower right, at the epicardial membrane rather than the endocardial membrane, at the left atrium rather than the right atrium, and at the posterior wall rather than the anterior wall. The main markers used for cardiac autonomic nerves were tyrosine hydroxylase and acetylcholine transferase. Protein gene product 9.5 was used to label the immunoreactive nerve distribution, and the distribution density of autonomic nerves was determined using a computer-aided morphometric analysis system.CONCLUSION: The uneven distribution of the cardiac autonomic nerves is the leading cause of the occurrence of arrhythmia, and the cardiac autonomic nerves play an important role in the

  14. 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.

  15. Imaging the ocular motor nerves.

    Science.gov (United States)

    Ferreira, Teresa; Verbist, Berit; van Buchem, Mark; van Osch, Thijs; Webb, Andrew

    2010-05-01

    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 7.0T 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.

  16. 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.

  17. Human amniotic epithelial cells express specific markers of nerve cells and migrate along the nerve fibers in the corpus callosum

    Institute of Scientific and Technical Information of China (English)

    Zhiyuan Wu; Guozhen Hui; Yi Lu; Tianjin Liu; Qin Huang; Lihe Guo

    2012-01-01

    Human amniotic epithelial cells were isolated from a piece of fresh amnion. Using immunocytochemical methods, we investigated the expression of neuronal phenotypes (microtubule-associated protein-2, glial fibrillary acidic protein and nestin) in human amniotic epithelial cells. The conditioned medium of human amniotic epithelial cells promoted the growth and proliferation of rat glial cells cultured in vitro, and this effect was dose-dependent. Human amniotic epithelial cells were further transplanted into the corpus striatum of healthy adult rats and the grafted cells could integrate with the host and migrate 1-2 mm along the nerve fibers in corpus callosum. Our experimental findings indicate that human amniotic epithelial cells may be a new kind of seed cells for use in neurograft.

  18. 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.

  19. 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...

  20. 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.

  1. Development and preclinical evaluation of acellular collagen scaffolding and autologous artificial connective tissue in the regeneration of oral mucosa wounds.

    Science.gov (United States)

    Espinosa, Lady; Sosnik, Alejandro; Fontanilla, Marta R

    2010-05-01

    This work assessed wound healing response in rabbit oral lesions grafted with autologous artificial connective tissue or acellular collagen scaffolds. Autologous artificial oral connective tissue (AACT) was produced using rabbit fibroblasts and collagen I scaffolds. Before implantation, AACT grafts were assayed to demonstrate the presence of fibroblasts and extracellular matrix components, as well as the expression of characteristic genes and secretion of chemokines, cytokines, and growth factors. AACT grafts were tested in the rabbits from which the fibroblasts were obtained, whereas acellular collagen type I scaffolds (CS) were evaluated in a separate group of rabbits. In both cases, contralateral wounds closed by secondary intention were used as controls. In a separate experiment, AACT-grafted wounds were directly compared with contralateral CS-grafted wounds in the same animals. Wound contraction and histological parameters were examined to evaluate closure differences between the treatments in the three animal experiments performed. Contraction of wounds grafted with AACT and CS was significantly lower than in their controls (p oral mucosa.

  2. Nanotribological study of grafted polymer

    Science.gov (United States)

    Bouhacina, T.; Aimé, J. P.; Attias, A. J.

    1998-06-01

    The frictional forces between grafted layers, organosilanes and polymer, on silica and a nanotip have been investigated as a function of the tip velocity. From the interpretation of these results and one gets a step forward for more quantitative information. Les forces de friction entre des couches greffées sur silice et une nanopointe ont été étudiées en fonction de la vitesse de la pointe. À partir de l'interprétation de ces résultats on s'avance vers plus d'infor mations quantitatives.

  3. 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

  4. 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.

  5. 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.

  6. 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...

  7. Artificial intelligence and psychiatry.

    Science.gov (United States)

    Servan-Schreiber, D

    1986-04-01

    This paper provides a brief historical introduction to the new field of artificial intelligence and describes some applications to psychiatry. It focuses on two successful programs: a model of paranoid processes and an expert system for the pharmacological management of depressive disorders. Finally, it reviews evidence in favor of computerized psychotherapy and offers speculations on the future development of research in this area.

  8. 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.

  9. 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.

  10. Radiation resistivity of polyacenaphthylene-grafted polyethylene

    Science.gov (United States)

    Hayakawa, Kiyoshi; Kawase, Kaoru; Yamakita, Hiromi

    Thin poly (ethylene-g-acenaphthylene) films prepared by the vapor-phase grafting method were subjected to the γ-irradiation in air, and various changes in tensile and structural properties of the film were investigated by comparing with those of the untreated or crosslinked polyethylene film. Polyethylene got to lose its inherent necking property by oxidative degradation and to be brittle-fractured by the irradiation dose less than 100 Mrad in air. The polyacenaphthylene-grafted polyethylenes (extent of grafting, ˜ 54 by {100( P-P°) }/{P°}), however, kept their ductility up to 200 Mrad or more, and the rate of increase in elastic modulus as well as yield strength with the increasing irradiation dose was considerably lower than that of untreated or crosslinked polyethylene. The effect of the grafting extent, and that of the irradiation dose-rate on the fracture energy were also examined. The weight increase of polyethylene due to the oxygen consumption and the resulting formation of carbonyl group which proceeded proportionally with the irradiation dose were remarkably suppressed by the grafting, whereas the double bond formation seemed to be unaffected by it. The grafted film held the original content of gel fraction unchanged during the irradiation in air, but the average molecular weight of the sol fraction decreased gradually. Meanwhile, the gel fraction of the crosslinked polyethylene was degenerated by a small dose of irradiation. The analysis of gaseous products revealed the formation of water, methanol, acetaldehyde and so forth from the irradiated grafted film. The grafting procedure and the subsequent irradiation of the grafted film did not affect the degree of crystallinity of the backbone polyethylene. The role played by the grafted polyacenaphthylene for endowing the radiation resistivity to polyethylene and its inherent limitation in effect were discussed from the structural point of view of the grafted film.

  11. Nerve injuries about the elbow.

    Science.gov (United States)

    Hariri, Sanaz; McAdams, Timothy R

    2010-10-01

    The ulnar, radial, median, medial antebrachial cutaneous, and lateral antebrachial cutaneous nerves are subject to traction and compression in athletes who place forceful, repetitive stresses across their elbow joint. Throwing athletes are at greatest risk, and cubital tunnel syndrome (involving the ulnar nerve) is clearly the most common neuropathy about the elbow. The anatomy and innervation pattern of the nerve involved determines the characteristic of the neuropathy syndrome. The most important parts of the work-up are the history and physical examination as electrodiagnostic testing and imaging are often not reliable. In general, active rest is the first line of treatment. Tailoring the surgery and rehabilitation protocol according to the functional requirements of that athlete's sport(s) can help optimize the operative outcomes for recalcitrant cases.

  12. Facial nerve paralysis in children.

    Science.gov (United States)

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-12-16

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology.

  13. Neuronal differentiation of PC12 cells induced by sciatic nerve and optic nerve conditioned medium

    Institute of Scientific and Technical Information of China (English)

    DU Chan; YANG De-mei; ZHANG Pei-xun; DENG Lei; JIANG Bao-guo

    2010-01-01

    Background Previous work has shown that optic nerve and sciatic nerve conditional medium had neurotrophic activity on neurons. In order to find if the optic nerve conditioned media (CM) had a similar activity to make PC12 cells differentiate as sciatic nerve CM did, we explored the neurotrophic activity in optic nerve CM in the same in vitro system and compared the neurotrophin expression levels in optic and sciatic nerves under both conditions.Methods PC12 cells were used to examine the effects of neurotrophins secreted by the sciatic nerve and optic nerve. RT-PCR and real-time QPCR showed that the sciatic nerve and optic nerve produced a range of neurotrophins including nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3).Results The effects of sciatic nerve and optic nerve CM on neurite outgrowth were tested against a range of neurotrophins, and they had different neuritogenic activities. Only NGF and sciatic nerve CM had obvious neuritogenic activities, although the concentration of NGF in the sciatic nerve CM was very low.Conclusions Our experiment showed that sciatic nerve CM had a higher neurotrophic activity on PC12 cells than optic nerve CM. These results suggested that peripheral nervous system (PNS) and central nervous system (CNS) had different expression levels of neurotrophin, which may in part explain the lack of ability to regenerate the CNS.

  14. 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.

  15. 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.

  16. 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....

  17. 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.

  18. PDGFBB promotes PDGFR{alpha}-positive cell migration into artificial bone in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shigeyuki [Department of Dentistry and Oral Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Iwasaki, Ryotaro; Kawana, Hiromasa [Department of Dentistry and Oral Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Miyauchi, Yoshiteru [Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Integrated Bone Metabolism and Immunology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Hoshi, Hiroko; Miyamoto, Hiroya; Mori, Tomoaki [Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Kanagawa, Hiroya [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Katsuyama, Eri; Fujie, Atsuhiro [Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Hao, Wu [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); and others

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer We examined effects of PDGFBB in PDGFR{alpha} positive cell migration in artificial bones. Black-Right-Pointing-Pointer PDGFBB was not expressed in osteoblastic cells but was expressed in peripheral blood cells. Black-Right-Pointing-Pointer PDGFBB promoted PDGFR{alpha} positive cell migration into artificial bones but not osteoblast proliferation. Black-Right-Pointing-Pointer PDGFBB did not inhibit osteoblastogenesis. -- Abstract: Bone defects caused by traumatic bone loss or tumor dissection are now treated with auto- or allo-bone graft, and also occasionally by artificial bone transplantation, particularly in the case of large bone defects. However, artificial bones often exhibit poor affinity to host bones followed by bony union failure. Thus therapies combining artificial bones with growth factors have been sought. Here we report that platelet derived growth factor bb (PDGFBB) promotes a significant increase in migration of PDGF receptor {alpha} (PDGFR{alpha})-positive mesenchymal stem cells/pre-osteoblastic cells into artificial bone in vivo. Growth factors such as transforming growth factor beta (TGF{beta}) and hepatocyte growth factor (HGF) reportedly inhibit osteoblast differentiation; however, PDGFBB did not exhibit such inhibitory effects and in fact stimulated osteoblast differentiation in vitro, suggesting that combining artificial bones with PDGFBB treatment could promote host cell migration into artificial bones without inhibiting osteoblastogenesis.

  19. Ethylene vinyl acetate based radiation grafted hydrophilic matrices: Process parameter standardization, grafting kinetics and characterization

    Science.gov (United States)

    Chaudhari, C. V.; Mondal, R. K.; Dubey, K. A.; Grover, V.; Panicker, L.; Bhardwaj, Y. K.; Varshney, L.

    2016-08-01

    A transparent, elastomeric, grafted matrix for several potential applications was synthesized by single-step simultaneous radiation grafting of methacrylic acid onto ethylene vinyl acetate (EVA). CuSO4 was found to be the most suitable homo-polymerization inhibitor among different inhibitors tried. The grafting kinetics was found to be a strong function of dose rate (D) and monomer content (M) and an equation relating grafting rate Rg=Kg [M]1.13D0.23 was deduced. Crystallinity of the grafted matrices as assessed from XRD and DSC measurements indicated decrease in crystalline content with increase in grafting yield, suggesting crystalline domain of EVA get disrupted on grafting. Elastic modulus increased linearly with the increase in grafting yield, though elongation at break decreased precipitously from 900% to 30% at even ~9% grafting. Thermo-gravimetric analysis showed three step weight loss of the grafted EVA matrix. The grafting of MAA resulted in increase in surface energy mainly due to enhanced polar component.

  20. A novel initiating system for wool grafting

    Directory of Open Access Journals (Sweden)

    Magdy Kandil Zahran

    2016-05-01

    Full Text Available This paper describes a new method for the grafting of methacrylic acid (MAA and other acrylic monomers onto wool fabric in aqueous medium. The novelty principally concerns the chemical approach of the redox grafting reaction that was carried out in the presence of sodium perborate (SPB initiator. Before the grafting reaction was started, the wool fabric was treated first with a freshly prepared ferrous ammonium sulfate (FAS solution. The so-treated fabric formed, with SPB, an efficacious redox system capable of initiating grafting of methacrylic acid (MAA and other acrylic monomers onto the wool fabric. The effect of the polymerization conditions on the polymer criteria, namely, graft yield (%GY, homopolymer (%HP, total conversion (%TC, and grafting efficiency (%GE, was studied. These polymer criteria were found to depend spaciously upon concentrations of the Fe2+ ion (activator, SPB (initiator, and MAA, pH of the polymerization medium, duration and temperature of polymerization. The graft copolymerization reaction has also been carried out in the presence of polymerization activators (e.g. reductant transition metal ions and an inhibitor (e.g. hydroquinone. A suitable mechanism for the grafting processes has been suggested, in accordance with the experimental results.

  1. Multimodality imaging of coronary artery bypass grafts

    NARCIS (Netherlands)

    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 c

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

    Science.gov (United States)

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

    2017-04-01

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

  3. 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

  4. Infraspinatus muscle atrophy from suprascapular nerve compression.

    Science.gov (United States)

    Cordova, Christopher B; Owens, Brett D

    2014-02-01

    Muscle weakness without pain may signal a nerve compression injury. Because these injuries should be identified and treated early to prevent permanent muscle weakness and atrophy, providers should consider suprascapular nerve compression in patients with shoulder muscle weakness.

  5. Optic nerve invasion of uveal melanoma

    DEFF Research Database (Denmark)

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

    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......; and 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...

  6. Vagus Nerve Stimulation for Treating Epilepsy

    Science.gov (United States)

    ... Evidence-based Guideline for PATIENTS and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you understand how vagus nerve stimulation (VNS) may help treat epilepsy. The American ...

  7. Polyethylene oxide hydration in grafted layers

    Science.gov (United States)

    Dormidontova, Elena; Wang, Zilu

    Hydration of water soluble polymers is one of the key-factors defining their conformation and properties, similar to biopolymers. Polyethylene oxide (PEO) is one of the most important biomedical-applications polymers and is known for its reverse temperature solubility due to hydrogen bonding with water. As in many practical applications PEO chains are grafted to surfaces, e.g. of nanoparticles or planar surfaces, it is important to understand PEO hydration in such grafted layers. Using atomistic molecular dynamic simulations we investigate the details of molecular conformation and hydration of PEO end-grafted to gold surfaces. We analyze polymer and water density distribution as a function of distance from the surface for different grafting densities. Based on a detailed analysis of hydrogen bonding between polymer and water in grafted PEO layers, we will discuss the extent of PEO hydration and its implication for polymer conformation, mobility and layer properties. This research is supported by NSF (DMR-1410928).

  8. Graft Take-Rates After Tympanoplasty

    DEFF Research Database (Denmark)

    Andersen, Steven Arild Wuyts; Aabenhus, Kristine; Glad, Henrik;

    2014-01-01

    , technique, graft material, and revision surgery) for tympanoplasty type I were studied. A comparison with the graft take-rates for tympanoplasty types II to IV and/or cholesteatoma was made. RESULTS: A user-friendly ear surgery database with fast data entry and direct import of audiometric data......OBJECTIVE: To present a prospective ear surgery database and investigate the graft take-rate and prognostic factors for graft take-rate in tympanoplasty using the database. STUDY DESIGN: Prospective database study. SETTING: Tertiary referral center. PATIENTS: A total of 1606 cases undergoing...... tympanoplasty types I to IV were registered in the database in the period from February 2004 to November 2013. INTERVENTION: A total of 837 cases underwent myringoplasty/tympanoplasty type I. MAIN OUTCOME MEASURE: Graft take-rate and prognostic factors (age, discharge at time of surgery, tuba function...

  9. Outcome of contralateral C7 nerve transferring to median nerve

    Institute of Scientific and Technical Information of China (English)

    GAO Kai-ming; LAO Jie; ZHAO Xin; GU Yu-dong

    2013-01-01

    Background Contralateral C7 (cC7) transfer had been widely used in many organizations in the world,but the outcomes were significantly different.So the purpose of the study was to evaluate the outcome of patients treated with cC7 transferring to median nerve and to determine the factors affecting the outcome of this procedure.Methods A retrospective review of 51 patients with total root avulsion brachial plexus injuries who underwent cC7 transfer was conducted.All of the surgeries were performed with two surgery stages and median nerve was the recipient nerve.The cC7 nerve was used in three different ways.The entire C7 root was used in 11 patients; the posterior division together with the lateral part of the anterior division was used in 15 patients; the anterior or the posterior division alone was used in 25 patients.The mean follow-up period was 6.9 years.Results The efficiency of the surgery in these 51 patients was 49.02% in motor and 62.75% in sensory function.The patients with entire C7 root transfer obtained significantly better recovery in both motor and sensory function than the patients with partial C7 transfer.The best function recovery could be induced if the interval between the two surgery stages was 4-8 months.Conclusions cC7 transfer is an effective procedure in repairing median nerve.But using the entire C7 root transfer can obtain better recovery; so we emphasize using the entire root as the donor.The optimal interval between two surgery stages is 4-8 months.

  10. Mesenchymal stem cells support hepatocyte function in engineered liver grafts.

    Science.gov (United States)

    Kadota, Yoshie; Yagi, Hiroshi; Inomata, Kenta; Matsubara, Kentaro; Hibi, Taizo; Abe, Yuta; Kitago, Minoru; Shinoda, Masahiro; Obara, Hideaki; Itano, Osamu; Kitagawa, Yuko

    2014-01-01

    Recent studies suggest that organ decellularization is a promising approach to facilitate the clinical application of regenerative therapy by providing a platform for organ engineering. This unique strategy uses native matrices to act as a reservoir for the functional cells which may show therapeutic potential when implanted into the body. Appropriate cell sources for artificial livers have been debated for some time. The desired cell type in artificial livers is primary hepatocytes, but in addition, other supportive cells may facilitate this stem cell technology. In this context, the use of mesenchymal stem cells (MSC) is an option meeting the criteria for therapeutic organ engineering. Ideally, supportive cells are required to (1) reduce the hepatic cell mass needed in an engineered liver by enhancing hepatocyte function, (2) modulate hepatic regeneration in a paracrine fashion or by direct contact, and (3) enhance the preservability of parenchymal cells during storage. Here, we describe enhanced hepatic function achieved using a strategy of sequential infusion of cells and illustrate the advantages of co-cultivating bone marrow-derived MSCs with primary hepatocytes in the engineered whole-liver scaffold. These co-recellularized liver scaffolds colonized by MSCs and hepatocytes were transplanted into live animals. After blood flow was established, we show that expression of adhesion molecules and proangiogenic factors was upregulated in the graft.

  11. 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

  12. Drug Delivery for Peripheral Nerve Regeneration

    Science.gov (United States)

    2015-11-01

    compared functional recovery between an autograft, PLGA nerve conduit, and PLGA nerve conduit that releases NGF in a rat sciatic nerve gap model...and scope of the research. Combat gear for the modern day warrior has greatly improved protection for the head and body, but limbs are still...and non-combat veterans peripheral nerve injuries affect 2-3% of trauma patients and vastly more subsequent to tumor extirpation or iatrogenic

  13. 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.

  14. 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.

  15. 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.

  16. Diverse mechanisms for assembly of branchiomeric nerves

    OpenAIRE

    Cox, Jane A.; LaMora, Angela; Johnson, Stephen L.; 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...

  17. A Review of Facial Nerve Anatomy

    OpenAIRE

    2004-01-01

    An intimate knowledge of facial nerve anatomy is critical to avoid its inadvertent injury during rhytidectomy, parotidectomy, maxillofacial fracture reduction, and almost any surgery of the head and neck. Injury to the frontal and marginal mandibular branches of the facial nerve in particular can lead to obvious clinical deficits, and areas where these nerves are particularly susceptible to injury have been designated danger zones by previous authors. Assessment of facial nerve function is no...

  18. Simultaneous paresthesia of the lingual nerve and inferior alveolar nerve caused by a radicular cyst.

    Science.gov (United States)

    Hamada, Yoshiki; Yamada, Hiroyuki; Hamada, Akiko; Kondoh, Toshirou; Suzuki, Mami; Noguchi, Kazuhide; Ito, Ko; Seto, Kanichi

    2005-10-01

    The inferior alveolar nerve is sometimes affected by periapical pathoses and mandibular cysts. However, mandibular intraosseous lesions have not been reported to disturb the lingual nerve. A case of simultaneous paresthesia of the right lingual nerve and the right inferior alveolar nerve is presented. The possible mechanisms of this extremely uncommon condition are discussed.

  19. [Transformation of trigeminal nerve tumor into malignant peripheral nerve sheath tumor (MPNST)].

    Science.gov (United States)

    Nenashev, E A; Cherekaev, V A; Kadasheva, A B; Kozlov, A V; Rotin, D L; Stepanian, M A

    2012-01-01

    Malignant peripheral nerve sheath tumor (MPNST) is a rare entity with only 18 cases of trigeminal nerve MPNST described by now and only one report of malignant transformation of trigeminal nerve tumor into MPNST published up to date. One more case of malignant transformation of trigeminal nerve (1st division) tumor into MPNST is demonstrated.

  20. 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