Increased susceptibility to development of anhedonia in rats with chronic peripheral nerve injury: Involvement of sleep deprivation?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microscopic Evidences That Bone Marrow Mononuclear Cell Treatment Improves Sciatic Nerve Regeneration After Neurorrhaphy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The role of the vagus nerve in the generation of cardiorespiratory interactions in a neotropical fish, the pacu, Piaractus mesopotamicus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative study between fibrin glue and platelet rich plasma in dogs skin grafts

OBJETIVO: Comparar a cola de fibrina (Tissucol®) e o plasma rico em plaquetas em enxertos cutâneos de espessura completa em malha em cães. MÉTODOS: Foram utilizados 18 cães, distribuídos em dois grupos, cola de fibrina (CF) e plasma rico em plaquetas (PRP). em todos os animais foi realizado um enxerto cutâneo de 3x3 cm, em malha de espessura completa. No membro esquerdo foi colocado o biomaterial entre o enxerto e o leito receptor, cada qual em seu grupo, o membro direito serviu como grupo controle. Todos os animais foram avaliados clinicamente a cada 48 horas até o décimo quarto dia, através das variáveis: exsudação, coloração, edema e aspecto cosmético; histologicamente em três animais, no terceiro, sétimo e décimo quarto dia de pós-operatório através das variáveis: fibroblastos, colágeno, tecido de granulação, integração-aderência microscópica e inflamação aguda. RESULTADOS: Avaliações clínicas demonstraram que o grupo CF apresentou melhor escores em todas variáveis quando comparado com o grupo PRP. Nas avaliações histológicas o grupo PRP apresentou maior presença de fibroblastos ao sétimo e décimo quarto dia. CONCLUSÃO: A cola de fibrina foi clinicamente superior ao grupo plasma rico em plaquetas quando usados em enxertos cutâneos de espessura completa em cães.

Effect of electrical stimulation of the cranial tibial muscle after end-to-side neurorrhaphy of the peroneal nerve in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

2 END-TO-SIDE NEURORRHAPHIES AND NERVE GRAFT WITH REMOVAL OF THE EPINEURAL SHEATH - EXPERIMENTAL-STUDY IN RATS

We have studied a new type of end-to-side nerve repair in rats. The healthy (donor) nerve was not divided but an epineural window was created. In our experiment, a nerve graft bridged the tibial nerve to the distal end of the divided peroneal nerve. Electrophysiological studies showed electrical impulses conducted through both end-to-side nerve junctions. Histological studies demonstrated axons leaving the lateral surface of the healthy (donor) nerve. Based on these observations, we suggest that end-to-side neurorrhaphy from a healthy nerve may bridge a neural deficit.

Evaluation of autogenous bone grafts, particulate or collected during osteotomy with implant burs: Histologic and histomorphometric analysis in rabbits

Purpose: the aim of this study was to evaluate bone regeneration in bone cavities filled with particulate autogenous bone either harvest in blocks and subjected to milling procedures or collected during osteotomy with implant burs. Materials and Methods: In 12 rabbits, 3 noncritical unicortical cavities 7 mm in diameter were prepared with a trephine drill on the right tibia. The cavities were filled respectively with particulate autogenous bone achieved with a manual bone crusher ( particulate group), with particulate autogenous bone obtained using bone collector during osteotomy ( collected group), and with blood clot ( control group). Animals were sacrificed at 7, 15, and 30 days after surgery ( 4 animals for each time period). The sections were examined by histologic and histomorphometric analysis. Results: At 7 days, the samples were filled by coagulum, and bone particles were observed only in the collected (24%) and particulate groups (44.75%). At 15 days, there was connective differentiation in all groups, with presence of grafted bone particles and onset of newly formed bone in the collected (38.88%) and particulate groups (46.0%). At 30 days, there was bone fill ( immature trabecular bone) of the cavities in the control (50%), collected (64.63%) and particulate groups (66%). Conclusion: No significant difference was demonstrated between noncritical unicortical bone defects in rabbit tibiae filled with particulate bone harvested as a block and subjected to milling and those filled with bone collected during osteotomy with implant drills when the defects were observed up to 30 days following their creation.

Localization and irregular distribution of Na,K-ATPase in myelin sheath from rat sciatic nerve

Sodium, potassium adenosine triphosphatase (Na,K-ATPase) is a membrane-bound enzyme that maintains the Na+ and K+ gradients used in the nervous system for generation and transmission of bioelectricity. Recently, its activity has also been demonstrated during nerve regeneration. The present study was undertaken to investigate the ultrastructural localization and distribution of Na,K-ATPase in peripheral nerve fibers. Small blocks of the sciatic nerves of male Wistar rats weighing 250-300g were excised, divided into two groups, and incubated with and without substrate, the para-nitrophenyl phosphate (pNPP). The material was processed for transmission electron microscopy, and the ultra-thin sections were examined in a Philips CNI 100 (TM) electron microscope. The deposits of reaction product were localized mainly on the axolemma, on axoplasmic profiles, and irregularly dispersed on the myelin sheath, but not in the unmyelinated axons. In the axonal membrane, the precipitates were regularly distributed on the cytoplasmic side. These results together with published data warrant further studies for the diagnosis and treatment of neuropathies with compromised Na,K-ATPase activity. (c) 2007 Elsevier Ltd. All rights reserved.

GENETIC INSTABILITY IN NERVE SHEATH CELL TUMORS

After in vitro culture, we analyzed cytogenetically four acoustic nerve neurinomas, one intraspinal neurinoma and one neurofibroma obtained from unrelated patients. Monosomy of chromosomes 22 and 16 was an abnormality common to all cases, followed in frequency by loss of chromosomes 18 (three cases) and chromosomes 8, 17 and 19 (two cases). Trisomy of chromosome 20 was also detected in two cases. Structural rearrangements were detected at low frequencies, with del(10)(p12) being present in two cases. In addition, we observed cell subpopulations showing a certain degree of genetic instability, reflected by the presence of polyploid cells with inconsistent abnormalities, endoreduplications and telomeric associations resulting in dicentric chromosomes. It is probable that these cytogenetic abnormalities represent some kind of evolutionary advantage for the in vitro progression of nerve sheath tumors.