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Nerve Injury Model (nerve + injury_model)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

The Effect of Hyperbaric Oxygen Therapy on Erectile Function Recovery in a Rat Cavernous Nerve Injury Model

THE JOURNAL OF SEXUAL MEDICINE, Issue 3 2008
Alexander Müller MD
ABSTRACT Introduction., Cavernosal oxygenation appears to be important for preservation of erectile tissue health. Hyperbaric oxygen therapy (HBOT) has been shown to improve tissue oxygenation and has neuromodulatory effects. Aim., This study was designed to define the effects of HBOT on erectile function (EF) and cavernosal tissue in the rat cavernous nerve (CN) injury model. Methods., Four groups of Sprague-Dawley rats were studied: rats with bilateral CN crush, HBOT treated (Crush+/HBOT+); bilateral CN-crush/no HBOT (C+/H,); no crush/no HBOT (C,/H,); and no crush/HBOT (C,/H+). HBOT was delivered daily for 90 minutes at three atmospheres for 10 days commencing the day of CN crush. Main Outcome Measures., Ten days after CN injury, the animals underwent CN stimulation measuring the maximal intracavernosal pressure/mean arterial pressure (ICP/MAP) ratios. Corporal tissue was harvested pre-sacrifice, and immunohistochemically stained for nerve growth factor (NGF), endothelial nitric oxide synthase (eNOS), and cluster of differentiation molecule (CD31). Histologic analysis was performed for Masson's trichrome to assess the smooth muscle,collagen ratio. Terminal deoxynucleotidyl transferase Biotin-dUTP Nick End Labeling assay was used to define apoptotic indices (AIs). Results., The C+/H, group had significantly lower ICP/MAP ratios compared with C,/H, rats, (31% vs. 70%, P < 0.001). C+/H+ rats had significantly higher ICP/MAP ratio recovery compared with the C+/H, group (55% vs. 31%, P = 0.005). NGF and eNOS staining densities were higher in C+/H+ rats compared with C+/H, rats (P < 0.05 and P < 0.001, respectively). No difference was seen in CD31 expression. Staining density for MT displayed a trend toward higher smooth muscle preservation after HBOT. AIs were significantly increased by HBOT (P < 0.05). Conclusion., HBOT following a CN injury improved EF preservation in this model, supporting the cavernosal oxygenation concept as protective mechanism for EF. The effects appear to be mediated via preservation of neurotrophic and endothelial factor expression. Müller A, Tal R, Donohue JF, Akin-Olugbade Y, Kobylarz K, Paduch D, Cutter SC, Mehrara BJ, Scardino PT, and Mulhall JP. The effect of hyperbaric oxygen therapy on erectile function recovery in a rat cavernous nerve injury model. J Sex Med 2008;5:562,570. [source]

Effect of neurotrophin-3 on reinnervation of the larynx using the phrenic nerve transfer technique

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2007
Paul J. Kingham
Abstract Current techniques for reinnervation of the larynx following recurrent laryngeal nerve (RLN) injury are limited by synkinesis, which prevents functional recovery. Treatment with neurotrophins (NT) may enhance nerve regeneration and encourage more accurate reinnervation. This study presents the results of using the phrenic nerve transfer method, combined with NT-3 treatment, to selectively reinnervate the posterior cricoarytenoid (PCA) abductor muscle in a pig nerve injury model. RLN transection altered the phenotype and morphology of laryngeal muscles. In both the PCA and thyroarytenoid (TA) adductor muscle, fast type myosin heavy chain (MyHC) protein was decreased while slow type MyHC was increased. These changes were accompanied with a significant reduction in muscle fibre diameter. Following nerve repair there was a progressive normalization of MyHC phenotype and increased muscle fibre diameter in the PCA but not the TA muscle. This correlated with enhanced abductor function indicating the phrenic nerve accurately reinnervated the PCA muscle. Treatment with NT-3 significantly enhanced phrenic nerve regeneration but led to only a small increase in the number of reinnervated PCA muscle fibres and minimal effect on abductor muscle phenotype and morphology. Therefore, work exploring other growth factors, either alone or in combination with NT-3, is required. [source]

Effects of axotomy on telomere length, telomerase activity, and protein in activated microglia

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2005
Barry E. Flanary
Abstract The adult central nervous system (CNS) is generally thought of as a postmitotic organ. However, DNA labeling studies have shown that one major population of nonneuronal cells, called microglia, retain significant mitotic potential. Microglial cell division is prominent during acute CNS injury involving neuronal damage or death. Prior work from this laboratory has shown that purified microglia maintained in vitro with continual mitogenic stimulation exhibit telomere shortening before entering senescence. In the current study, we sought to investigate whether telomere shortening occurs in dividing microglia in vivo. For this purpose, we used a nerve injury model that is known to trigger localized microglial proliferation in a well-defined CNS region, the facial motor nucleus. Adult Sprague-Dawley rats underwent facial nerve axotomy, and facial motor nuclei were microdissected after 1, 4, 7, and 10 days. Whole tissue samples were subjected to measurements of telomere length, telomerase activity, and telomerase protein. Results revealed a tendency for all of these parameters to be increased in lesioned samples. In addition, microglial cells isolated directly from axotomized facial nuclei with fluorescence-activated cell sorting (FACS) showed increased telomerase activity relative to unoperated controls, suggesting that microglia are the primary cell type responsible for the increases observed in whole tissue samples. Overall, the results show that microglia activated by injury are capable of maintaining telomere length via telomerase during periods of high proliferation in vivo. We conclude that molecular mechanisms pertaining to telomere maintenance are active in the injured CNS. © 2005 Wiley-Liss, Inc. [source]