Reconstruction of nerves

Computer reconstruction of nerve membrane behaviour in the presence of pyrethroids... 

Fig.6 Computer reconstruction of nerve membrane activity based on the existence in the membrane of a small proportion (A) of modified sodium channels. In panels A and B, this proportion was varied from zero to 0.048 (i.e. 4.8 % of modified channels) to reproduce the membrane potential changes observed in strongly poisoned insects. In panel C, repetitive firing was obtained by shifting the sodium inactivation curve towards more positive potentials. Tau p x 200 indicates that, for these examples, the time constant of activation of the modified channels was 100 times slower than that of the normal channels.

The use of nanocellulose has been suggested in different areas of medicine as substitute of blood vessels and linfatics (Yamanaka et al. 1990 Klemm et al. 2003) substitute of hollow internal organs as ureter, trachea, and digestive tract (Yamanaka et al. 1990 Klemm et al. 2003 Ono et al. 1989) cuff for reconstruction of nerves (Klemm et al. 2003) substitute of duramater (Oster et al. 2003 Damien et al. 2005) substitute of the abdominal wall, skin, subcutaneous tissue, articulation, cartilage, and reinforcement of areas of decreased resistance in the abdominal wall, esophagus, and intestinal tube (Ono et al. 1989) threads (Roberts et al. 1986) and agent for increases in soft tissue, reconstruction of the pelvic... 

Figure 24.1 A surface reconstruction of a male antennal lobe of the moth Spodoptera littoralis. The brain was immunostained with synapsin antibody and optically sectioned using a confocal microscope. Stacks of images were integrated with the software Imaris 2,7 (Bitplane AG, Switzerland) on a Silicon Graphics workstation to obtain surface projections of the lobe. The macroglomerular complex (MGC) is located close to the entrance of the antennal nerve. M, medial D, dorsal (modified from Carlsson et at, 2002). B Synaptic organization of the major types of antennal lobe neurons. Sensory neurons (ORNs) make uniglomerular synapses both directly with projection neurons (PNs) and indirectly via local interneurons (LNs). In addition, local interneurons innervate several glomeruli and generally make inhibitory synapses. Cell bodies of PNs and LNs are located within the antennal lobe.

Tuszynski, M. H., Buzsaki, G., and Gage, F. H., Nerve growth factor infusions combined with fetal hippocampal grafts enhance reconstruction of the lesioned septohip-pocampal projection, Neuroscience, 36, 33, 1990. 

The denervated endplate loses the complex of nerve terminals that had branched within it, and is seen as an empty structure. These pre-existing, empty endplates then are re-innervated by one or more growing axons, reconstructing the developmental stage of polyneuronal innervation. These changes are illustrated in Fig. 9. 

Suzuki K., Suzuki Y, Xanihara M., Ohnishi K., Hashimoto X, Endo K., Nishimura Y.Y., Reconstruction of rat peripheral nerve gap without sutures using freeze-dried alginate gel, J. Biomed. Mater. Res., 49(4), 1999, 528-533. 

Knee proprioception and SEPs to stimulation of the common peroneal nerve (CPN) were studied by Veleriani et al. in patients with ACL injury before and after ACL reconstruction [21]. Before surgery, all patients showed decreased knee position sense and lack of cortical P27 potential on the injured side. Arthroscopic reconstruction of the ligament was performed but knee proprioception and somatosensory central conduction did not recover to normal level. However, the loss of knee mechanoreceptors may possibly be restored by modifications of the CNS, which are not compensated by other nervous structures. 

Fig. 5.16. a Giant ICA aneurysm inducing optic nerve compression in a 10-year-old boy with visual deficit on the right eye. b Brain stem aneurysm between origin of the superior cerebellar artery and posterior cerebral artery resulting in right sided oculomotor palsy. c,d Pcom aneurysm (c DSA, lateral view) in a 46-year-old-patient with oculomotor palsy note the close relationship of the aneurysm and the oculomotor nerve (arrow) but without visible contact (d, sagittal reconstruction of CISS sequence)... 

Luis AL, Rodrigus JM, Lobato JV, Lopes MA, Amado S, Veloso AP, et al. Evaluation of two biodegradable nerve guides for the reconstruction of the rat sciatic nerve. Biomed Mater Eng 2007 17 39-52. 

Acellular nerve matrix allografts have also been observed as useful biomaterials for nerve regeneration [34]. These allografts preserve extracellular matrix (ECM) components and, therefore, mimic the ECM of peripheral nerves mechanically and physically. In this way, acellular nerve matrices aid in the reconstruction of the peripheral nerve. However, decellularization techniques, such as thermal deceUularization, can damage the ECM structure and fail to extract all cellular components leading to inflammation upon implantation [35]. 

Frerichs, O., Fansa, H., Schicht, C., Wolf, G., Schneider, W., and KeiUioff, G., Reconstruction of peripheral nerves using acellular nerve grafts with implanted cultured Schwann cells. Microsurgery, 22,311-315,2002. 

Skin A chemical bum was reported in a case of a 35-year-old man who xmderwent anterior cruciate ligament reconstruction of the left knee. A 5% aqueous solution of povidone-iodine was used as topical antiseptic and the partial thickness bum occurred xmdemeath the area of tourniquet application [77 ]. A case of massive adverse reaction (severe oedema and diffuse skin lesions) to the irrigation of surgical woxmd dehiscence with 10% povidone-iodine solution after deep-impacted, lower third molar extract was reported. The reaction was probably related to a peripheral chemical insult of mandible nerve [78 ]. 

Concurrent with these investigations, polyphosphazene matrices, functionalized with aminoacid esters or with imidazole groups, became of importance because of their tissue engineering aspects in bone regeneration [655,656,679], treatment of periodontal diseases [657], and nerve reconstruction problems [680-682] in which the remarkable bio compatibility of POP matrices was coupled with their tuneable bio degradability. 

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