Biomechanical gait analysis in sheep: kinematic parameters.

Animals have been used as models to help to better understand biological and anatomical systems, and pathologies in both humans and non-human species, and sheep are often used as an in vivo experimental model for orthopedic research. Gait analysis has been shown to be an important tool in biomechanics research with clinical applications. The purpose of this study was to perform a kinematic analysis using a tridimensional (3D) reconstruction of the sheep hindlimb. Seven healthy sheep were evaluated for natural overground walking, and motion capture of the right hindlimb was collected with an optoelectronic system while the animals walked in a track. The analysis addressed gait spatiotemporal variables, hip, knee and ankle angle and intralimb joint angle coordination measures during the entire walking cycle. This study is the first that describes the spatiotemporal parameters from the hip, knee and ankle joints in a tridimensional way: flexion/extension; abduction/adduction and inter/external rotation. The results of this assessment can be used as an outcome indicator to guide treatment and the efficacy of different therapies for orthopedic and neurological conditions involving the locomotor system of the sheep animal model.

Feocromocitoma y Paraganglioma: un reto más allá de la clínica / Pheochromocytoma and Paraganglioma: a Challenge beyond the Clinic

Resumen Los feocromocitomas y paragangliomas son tumores raros que se originan en las células cromafines. Tienen un amplio espectro clínico que va desde el hallazgo incidental hasta manifestaciones por la producción exagerada de catecolaminas. El diagnóstico bioquímico se realiza mediante medición de metanefrinas libres en plasma. El tratamiento ideal es la escisión quirúrgica completa previo bloqueo de receptores a y 6 adrenérgicos. En caso de enfermedad metastásica, las opciones de tratamiento sistêmico actuales son limitadas y con escasa tasa de respuesta. Está en investigación el uso de antiangiogénicos.

Abstract Pheochromocytomas and Paragangliomas are rare tumors, originated from the chromaffin cells. They have a broad clinical spectrum from incidental finding to full clinical manifestations explain to overproduction of catecholamines. The biochemistry diagnosis is made by the measurement of free Metanephrines in plasma. Complete surgical removal is the optimal treatment, previously having a y 6 adrenergic receptors blockage. In case of metastasic disease, treatment options are palliative, limited and with a low rate response; the use of antiangiogenic treatments is under investigation.

Combined Use of Chitosan and Olfactory Mucosa Mesenchymal Stem/Stromal Cells to Promote Peripheral Nerve Regeneration In Vivo.

Peripheral nerve injury remains a clinical challenge with severe physiological and functional consequences. Despite the existence of multiple possible therapeutic approaches, until now, there is no consensus regarding the advantages of each option or the best methodology in promoting nerve regeneration. Regenerative medicine is a promise to overcome this medical limitation, and in this work, chitosan nerve guide conduits and olfactory mucosa mesenchymal stem/stromal cells were applied in different therapeutic combinations to promote regeneration in sciatic nerves after neurotmesis injury. Over 20 weeks, the intervened animals were subjected to a regular functional assessment (determination of motor performance, nociception, and sciatic indexes), and after this period, they were evaluated kinematically and the sciatic nerves and cranial tibial muscles were evaluated stereologically and histomorphometrically, respectively. The results obtained allowed confirming the beneficial effects of using these therapeutic approaches. The use of chitosan NGCs and cells resulted in better motor performance, better sciatic indexes, and lower gait dysfunction after 20 weeks. The use of only NGGs demonstrated better nociceptive recoveries. The stereological evaluation of the sciatic nerve revealed identical values in the different parameters for all therapeutic groups. In the muscle histomorphometric evaluation, the groups treated with NGCs and cells showed results close to those of the group that received traditional sutures, the one with the best final values. The therapeutic combinations studied show promising outcomes and should be the target of new future works to overcome some irregularities found in the results and establish the combination of nerve guidance conduits and olfactory mucosa mesenchymal stem/stromal cells as viable options in the treatment of peripheral nerves after injury.

A Multimodal Stimulation Cell Culture Bioreactor for Tissue Engineering: A Numerical Modelling Approach.

The use of digital twins in tissue engineering (TE) applications is of paramount importance to reduce the number of in vitro and in vivo tests. To pursue this aim, a novel multimodal bioreactor is developed, combining 3D design with numerical stimulation. This approach will facilitate the reproducibility between studies and the platforms optimisation (physical and digital) to enhance TE. The new bioreactor was specifically designed to be additive manufactured, which could not be reproduced with conventional techniques. Specifically, the design suggested allows the application of dual stimulation (electrical and mechanical) of a scaffold cell culture. For the selection of the most appropriate material for bioreactor manufacturing several materials were assessed for their cytotoxicity. Numerical modelling methods were then applied to the new bioreactor using one of the most appropriate material (Polyethylene Terephthalate Glycol-modified (PETG)) to find the optimal stimulation input parameters for bone TE based on two reported in vitro studies.

Implementation of the International Classification of Functioning, Disability, and Health (ICF) Core Sets for Children and Youth with Cerebral Palsy: Global Initiatives Promoting Optimal Functioning.

Background: The International Classification of Functioning, Disability, and Health (ICF) Core Sets for children and youth with cerebral palsy (CP) offer service providers and stakeholders a specific framework to explore functioning and disability for assessment, treatment, evaluation, and policy purposes in a global context. Objective: Describe global initiatives applying the ICF Core Sets for children and youth with CP, with a focus on contributions to clinical practice and challenges in their implementation. Methods: This is a descriptive cross-sectional study. Ongoing initiatives applying the ICF Core Sets for CP in Russia, Poland, Malawi, and Brazil are included. Results: The main contributions of applying the ICF Core Sets for children and youth with CP include: (1) an objective description of abilities and limitations in everyday activities; (2) a consistent identification of facilitators and barriers influencing functioning; (3) a practical communication tool promoting client-centered care and multidisciplinary teamwork; and, (4) a useful guideline for measurement selection. The main challenges of adopting the ICF Core Sets are related to lack of ICF knowledge requiring intense training and translating results from standardized measures into the ICF qualifiers in a consistent way. Conclusions: Global initiatives include research and clinical applications at the program, service and system levels. The ICF Core Sets for CP are useful tools to guide service provision and build profiles of functioning and disability. Global interprofessional collaboration, capacity training, and informatics (e-records) will maximize their applications and accelerate adoption.

Evaluation of PVA biodegradable electric conductive membranes for nerve regeneration in axonotmesis injuries: the rat sciatic nerve animal model.

The therapeutic effect of three polyvinyl alcohol (PVA) membranes loaded with electrically conductive materials - carbon nanotubes (PVA-CNTs) and polypyrrole (PVA-PPy) - were tested in vivo for neuro-muscular regeneration after an axonotmesis injury in the rat sciatic nerve. The membranes electrical conductivity measured was 1.5 ± 0.5 × 10-6 S/m, 579 ± 0.6 × 10-6 S/m, and 1837.5 ± 0.7 × 10-6 S/m, respectively. At week-12, a residual motor and nociceptive deficit were present in all treated groups, but at week-12, a better recovery to normal gait pattern of the PVA-CNTs and PVA-PPy treated groups was observed. Morphometrical analysis demonstrated that PVA-CNTs group presented higher myelin thickness and lower g-ratio. The tibialis anterior muscle, in the PVA-PPy and PVA-CNTs groups showed a 9% and 19% increase of average fiber size area and a 5% and 10% increase of the "minimal Feret's diameter," respectively. No inflammation, degeneration, fibrosis or necrosis were detected in lung, liver, kidneys, spleen, and regional lymph nodes and absence of carbon deposits was confirmed with Von Kossa and Masson-Fontana stains. In conclusion, the membranes of PVA-CNTs and PVA-PPy are biocompatible and have electrical conductivity. The higher electrical conductivity measured in PVA-CNTs membrane might be responsible for the positive results on maturation of myelinated fibers. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1267-1280, 2017.

Trichobezoar - A Rare Cause of Abdominal Mass and Gastric Outlet Obstruction.

The authors present the clinical case of a 14-year old girl with weight loss, anorexia, epigastric abdominal pain and postprandial vomiting with 5 months duration. There was a background of trichophagia for 2 years without evidence of alopecia or psychiatric history. The physical examination revealed an epigastric mass motionless, stony, with poorly defined limits, painful on palpation and about 7 cm diameter. Abdominal ultrasonography showed thickening of the gastric wall and antrum with gastric distension. The abdominal tomography scan and endoscopic examination revealed the presence of a bulky trichobezoar occupying almost the entire gastric lumen. It was decided to undergo gastrotomy and extraction of the bezoar. The postoperative period was uneventful.

Apresentamos o caso clínico de uma adolescente de 14 anos com emagrecimento, anorexia, epigastralgia e vómitos pós-prandiais com 5 meses de evolução. Apurou-se história de tricofagia com 2 anos de evolução mas sem áreas de alopécia ou antecedentes psiquiátricos. Apresentava massa epigástrica imóvel, pétrea, de limites mal definidos, dolorosa à palpação e com cerca de 7 cm de diâmetro. A ecografia abdominal mostrou espessamento da parede gástrica e do antro com distensão gástrica. Realizou tomografia abdominal e endoscopia digestiva alta que revelaram a presença de volumoso tricobezoar ocupando quase a totalidade do lúmen gástrico. Foi decidido realizar gastrotomia e extração do bezoar. O pós-operatório decorreu sem incidentes.

Evaluation of biodegradable electric conductive tube-guides and mesenchymal stem cells.

AIM: To study the therapeutic effect of three tube-guides with electrical conductivity associated to mesenchymal stem cells (MSCs) on neuro-muscular regeneration after neurotmesis. METHODS: Rats with 10-mm gap nerve injury were tested using polyvinyl alcohol (PVA), PVA-carbon nanotubes (CNTs) and MSCs, and PVA-polypyrrole (PPy). The regenerated nerves and tibialis anterior muscles were processed for stereological studies after 20 wk. The functional recovery was assessed serially for gait biomechanical analysis, by extensor postural thrust, sciatic functional index and static sciatic functional index (SSI), and by withdrawal reflex latency (WRL). In vitro studies included cytocompatibility, flow cytometry, reverse transcriptase polymerase chain reaction and karyotype analysis of the MSCs. Histopathology of lung, liver, kidneys, and regional lymph nodes ensured the biomaterials biocompatibility. RESULTS: SSI remained negative throughout and independently from treatment. Differences between treted groups in the severity of changes in WRL existed, showing a faster regeneration for PVA-CNTs-MSCs (P < 0.05). At toe-off, less acute ankle joint angles were seen for PVA-CNTs-MSCs group (P = 0.051) suggesting improved ankle muscles function during the push off phase of the gait cycle. In PVA-PPy and PVA-CNTs groups, there was a 25% and 42% increase of average fiber area and a 13% and 21% increase of the "minimal Feret's diameter" respectively. Stereological analysis disclosed a significantly (P < 0.05) increased myelin thickness (M), ratio myelin thickness/axon diameter (M/d) and ratio axon diameter/fiber diameter (d/D; g-ratio) in PVA-CNT-MSCs group (P < 0.05). CONCLUSION: Results revealed that treatment with MSCs and PVA-CNTs tube-guides induced better nerve fiber regeneration. Functional and kinematics analysis revealed positive synergistic effects brought by MSCs and PVA-CNTs. The PVA-CNTs and PVA-PPy are promising scaffolds with electric conductive properties, bio- and cytocompatible that might prevent the secondary neurogenic muscular atrophy by improving the reestablishment of the neuro-muscular junction.

Síndrome de apnea/hipopnea obstructiva del sueño y su asociación con las enfermedades cardiovasculares / Obstructive Sleep Apnea Hypopnea Syndrome and its association with cardiovascular disease

Introducción:El síndrome de apnea/hipopnea obstructiva del sueño, es una entidad que ha cobrado importancia en los últimos años, con una prevalencia estimada en adultos de edad media cercana al 4 y al 2% en hombres y mujeres, respectivamente, y que por su frecuencia constituye un problema de salud pública. Objetivo:Exponer, tras un análisis exhaustivo de la literatura disponible, la asociación entre el síndrome de apnea/hipopnea obstructiva del sueño y las enfermedades cardiovasculares. Método: Se hizo una revisión narrativa a partir de la literatura encontrada en las bases de datos más reconocidas. Se incluyeron 59 estudios publicados en los últimos treinta años y se excluyeron reportes y series de casos. Conclusiones: El síndrome de apnea/hipopnea obstructiva del sueño se reconoce hoy en día como un problema de salud pública mundial. En Latinoamérica, más específicamente en Colombia, se requieren estudios prospectivos de cohorte que sirvan de pauta para la población del continente e indiquen posibles diferencias respecto a la comunidad internacional en cuanto a su tratamiento y diagnóstico oportunos, así como acerca del impacto de estos en lo concerniente a los desenlaces cardiovasculares de los pacientes.

Introduction: The Obstructive Sleep Apnea Hypopnea Syndrome has gained importance has gained importance in recent years, with an estimated prevalence in population of middle-aged adults around 4 and 2% in men and women respectively, and that given its frequency constitutes a public health problem. Objective: To show, after a thorough analysis of the available literature, the association between the Obstructive Sleep Apnea Hypopnea Syndrome and cardiovascular diseases. Method: A narrative review was made from the literature found at the most recognized databases. Fifty nine studies published in the last thirty years were included and reports and case series were excluded. Conclusions: The Obstructive Sleep Apnea Hypopnea Syndrome is recognized today as a global public health problem. Latin America, specifically Colombia, requires prospective cohort studies that serve as a guideline for the continent's population and that could indicate possible differences compared to the international community regarding early diagnosis and treatment, and its impact in cardiovascular outcomes of these patients.

Promoting nerve regeneration in a neurotmesis rat model using poly(DL-lactide-ε-caprolactone) membranes and mesenchymal stem cells from the Wharton's jelly: in vitro and in vivo analysis.

In peripheral nerves MSCs can modulate Wallerian degeneration and the overall regenerative response by acting through paracrine mechanisms directly on regenerating axons or upon the nerve-supporting Schwann cells. In the present study, the effect of human MSCs from Wharton's jelly (HMSCs), differentiated into neuroglial-like cells associated to poly (DL-lactide-ε-caprolactone) membrane, on nerve regeneration, was evaluated in the neurotmesis injury rat sciatic nerve model. Results in vitro showed successful differentiation of HMSCs into neuroglial-like cells, characterized by expression of specific neuroglial markers confirmed by immunocytochemistry and by RT-PCR and qPCR targeting specific genes expressed. In vivo testing evaluated during the healing period of 20 weeks, showed no evident positive effect of HMSCs or neuroglial-like cell enrichment at the sciatic nerve repair site on most of the functional and nerve morphometric predictors of nerve regeneration although the nociception function was almost normal. EPT on the other hand, recovered significantly better after HMSCs enriched membrane employment, to values of residual functional impairment compared to other treated groups. When the neurotmesis injury can be surgically reconstructed with an end-to-end suture or by grafting, the addition of a PLC membrane associated with HMSCs seems to bring significant advantage, especially concerning the motor function recovery.

Role of physical exercise for improving posttraumatic nerve regeneration.

Despite the great regenerative ability of the peripheral nervous system (PNS), traumatic peripheral nerve damage often causes severe chronic disability. Rehabilitation following PNS trauma usually employs therapeutic exercise in an attempt to reanimate the target organs and stimulate functional recovery. Over the past years, important neurobiological determinants of PNS regeneration and successful end-organ reinnervation were unveiled. Such knowledge provides cues for designing novel strategies for treating and rehabilitating traumatic PNS damage. Physical exercise, by means of treadmill or wheel running, is neuroprotective and neuroregenerative. Research conducted on rodents demonstrates that endurance exercise modulates several of the cellular and molecular responses to peripheral nerve injury and by doing so it stimulates nerve regeneration and functional recovery following experimental PNS injury. Treadmill running increases the number of regenerating neurons, the rate of axonal growth, and the extent of muscle reinnervation following peripheral nerve injury. Furthermore, treadmill running has the ability to increase the release of neurotrophins and growth factors in the spinal cord, the injured nerve, and reinnervating muscles. Treadmill running also seems to prevent the development of neuropathic pain and allodynia as a result of peripheral nerve damage. In addition, physical exercise, even if performed for a short period of time, exerts positive conditioning effects in neuroregeneration capacity, improving the acute response to peripheral nerve insults. Some of these effects can also be obtained with passive exercise or manual stimulation. In humans, however, evidence demonstrating a positive effect of exercise on nerve regeneration is at best poor.

Empiema Necessitatis / Empyema necessitatis

Se presenta el caso de un hombre de 73 años, agricultor, quien consulta por cuadro de tres meses de tos húmeda con expectoración verdosa, posteriormente hemoptoica, de predominio matutino, asociado a dolor lumbar izquierdo. Se documentó en imágenes empiema que se comunica con región lumbar izquierda, constituyendo así un cuadro de empiema necessitatis con presentación poco usual como lo es el drenaje hacia espacio paravertebral. (Acta Med Colomb 2013; 38: 28-31).

We present the case of a 73-year-old farmer, who consults for a 3 months clinical picture of wet cough with greenish sputum, subsequently hemoptoic predominantly in the mornings, associated with left lumbar pain. We documented in images empyema communicating with the left lumbar region, constituting an empyema necessitatis picture with unusual presentation as is the drainage to the paravertebral space. (Acta Med Colomb 2013; 38: 28-31).

The sensitivity of two-dimensional hindlimb joint kinematics analysis in assessing functional recovery in rats after sciatic nerve crush.

Walking analysis in the rat is increasingly used to assess functional recovery after peripheral nerve injury. Here we assess the sensitivity and specificity of hindlimb joint kinematics measures during the rat gait early after sciatic nerve crush injury (DEN), after twelve weeks of recovery (REINN) and in sham-operated controls (Sham) using discriminant analysis. The analysis addressed gait spatiotemporal variables and hip, knee and ankle angle and angular velocity measures during the entire walking cycle. In DEN animals, changes affected all studied joints plus spatiotemporal parameters of gait. Both the spatiotemporal and ankle kinematics parameters recovered to normality within twelve weeks. At this time point, some hip and knee kinematics values were still abnormal when compared to sham controls. Discriminant models based on hip, knee and ankle kinematics displayed maximal sensitivity to identify DEN animals. However, the discriminant models based on spatiotemporal and ankle kinematics data showed a poor performance when assigning animals to the REINN and Sham groups. Models using hip and knee kinematics during walking showed the best sensitivity to recognize the reinnervated animals. The model construed on the basis of hip joint kinematics was the one combining highest sensitivity with robustness and high specificity. It is concluded that ankle joint kinematics fails in detecting minor functional deficits after long term recovery from sciatic nerve crush and extending the kinematic analysis during walking to the hip and knee joints improves the sensitivity of this functional test.

Effects of collagen membranes enriched with in vitro-differentiated N1E-115 cells on rat sciatic nerve regeneration after end-to-end repair.

Peripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent of regeneration is often poor and may benefit from exogenous factors that enhance growth. The use of cellular systems is a rational approach for delivering neurotrophic factors at the nerve lesion site, and in the present study we investigated the effects of enwrapping the site of end-to-end rat sciatic nerve repair with an equine type III collagen membrane enriched or not with N1E-115 pre-differentiated neural cells. After neurotmesis, the sciatic nerve was repaired by end-to-end suture (End-to-End group), end-to-end suture enwrapped with an equine collagen type III membrane (End-to-EndMemb group); and end-to-end suture enwrapped with an equine collagen type III membrane previously covered with neural cells pre-differentiated in vitro from N1E-115 cells (End-to-EndMembCell group). Along the postoperative, motor and sensory functional recovery was evaluated using extensor postural thrust (EPT), withdrawal reflex latency (WRL) and ankle kinematics. After 20 weeks animals were sacrificed and the repaired sciatic nerves were processed for histological and stereological analysis. Results showed that enwrapment of the rapair site with a collagen membrane, with or without neural cell enrichment, did not lead to any significant improvement in most of functional and stereological predictors of nerve regeneration that we have assessed, with the exception of EPT which recovered significantly better after neural cell enriched membrane employment. It can thus be concluded that this particular type of nerve tissue engineering approach has very limited effects on nerve regeneration after sciatic end-to-end nerve reconstruction in the rat.

Use of chitosan scaffolds for repairing rat sciatic nerve defects.

Neurotmesis must be surgically treated by direct end-to-end suture of the two nerve stumps or by a nerve graft harvested from elsewhere in the body in case of tissue loss. To avoid secondary damage due to harvesting of the nerve graft, a tube-guide can be used to bridge the nerve gap. Previously, our group developed and tested hybrid chitosan membranes for peripheral nerve tubulization and showed that freeze-dried chitosan type III membranes were particularly effective for improving peripheral nerve functional recovery after axonotmesis. Chitosan type III membranes have about 110 microm pores and about 90% of porosity, due to the employment of freeze-drying technique. The present study aimed to verify if chitosan type III membranes can be successfully used also for improving peripheral nerve functional recovery after neurotmesis of the rat sciatic nerve. Sasco Sprague-Dawley adult rats were divided into 6 groups: Group 1: end-to-end neurorrhaphy enwrapped by chitosan membrane type III (End-to-EndChitll); Group 2: 10mm-nerve gap bridged by an autologous nerve graft enwrapped by chitosan membrane type III (Graf180degreeChitIII); Group 3: 10 mm-nerve gap bridged by chitosan type III tube-guides (GapChitIII); These 3 experimental groups were compared with 3 control groups, respectively: Group 4: 10 mm-nerve gap bridged by an autologous nerve graft (Graft180degree); Group 5: 10 mm-nerve gap bridged by PLGA 90:10 tube-guides (PLGA); Group 6: end-to-end neurorrhaphy alone (End-to-End). Motor and sensory functional recovery were evaluated throughout a healing period of 20 weeks using extensor postural thrust (EPT), withdrawal reflex latency (WRL) and ankle kinematics. Regenerated nerves withdrawn at the end of the experiment were analysed histologically. Results showed that nerve regeneration was successful in all experimental and control groups and that chitosan type III tubulization induced a significantly better nerve regeneration and functional recovery in comparison to PLGA tubulization control. Further investigation is needed to explore the mechanisms at the basis of the positive effects of chitosan type III on axonal regeneration.

Anatomical reference frame versus planar analysis: implications for the kinematics of the rat hindlimb during locomotion.

Functional recovery is the primary goal of therapeutic intervention in neuromuscular rehabilitation. The purpose of this study was to perform a segmental kinematic analysis using both planar angles computation and a tridimensional (3D) reconstruction of the rat hindlimb, regarding the morphology and the movement of each segment. Seven rats were evaluated for natural overground walking, and motion capture of the right hindlimb was collected with an optoeletronic system while the animals walked in the track. 3D biomechanical analyses were carried out and hip, knee, ankle, and metatarsophalangeal joint angular displacements were calculated. For flexion/extension, the knee joint and toe segment were statistically different between planar and 3D analysis, with the toe segment performing less extension at initial contact (IC) and the amplitude during swing phase for the knee being larger. During abduction/adduction, all hip joint parameters were statistically different except at IC and toe-off (TO) instants, the planar angles being higher than the 3D angles. In the horizontal plane, significant differences were found for ankle peaks of rotation, with increased results for the planar angles. In conclusion, a comparison between planar and 3D segmental kinematic analysis using a tridimensional reconstruction of the rat hindlimb demonstrated that different joints have different motion patterns within motion planes, probably related with physiological constraints and muscle actions. A major indication of the need for an anatomical reference frame kinematic analysis is supported by the knowledge that neuromuscular diseases are related to important clinical signs or motor deficits that should be observed, qualified, and quantified.

Use of PLGA 90:10 scaffolds enriched with in vitro-differentiated neural cells for repairing rat sciatic nerve defects.

Poly(lactic-co-glycolic acid) (PLGA) nerve tube guides, made of a novel proportion (90:10) of the two polymers, poly(L-lactide): poly(glycolide) and covered with a neural cell line differentiated in vitro, were tested in vivo for promoting nerve regeneration across a 10-mm gap of the rat sciatic nerve. Before in vivo testing, the PLGA 90:10 tubes were tested in vitro for water uptake and mass loss and compared with collagen sheets. The water uptake of the PLGA tubes was lower, and the mass loss was more rapid and higher than those of the collagen sheets when immersed in phosphate-buffered saline (PBS) solution. The pH values of immersing PBS did not change after soaking the collagen sheets and showed to be around 7.4. On the other hand, the pH values of PBS after soaking PLGA tubes decreased gradually during 10 days reaching values around 3.5. For the in vivo testing, 22 Sasco Sprague adult rats were divided into four groups--group 1: gap not reconstructed; group 2: gap reconstructed using an autologous nerve graft; group 3: gap reconstructed with PLGA 90:10 tube guides; group 4: gap reconstructed with PLGA 90:10 tube guides covered with neural cells differentiated in vitro. Motor and sensory functional recovery was evaluated throughout a healing period of 20 weeks using sciatic functional index, static sciatic index, extensor postural thrust, withdrawal reflex latency, and ankle kinematics. Stereological analysis was carried out on regenerated nerve fibers. Both motor and sensory functions improved significantly in the three experimental nerve repair groups, although the rate and extent of recovery was significantly higher in the group where the gap was reconstructed using the autologous graft. The presence of neural cells covering the inside of the PLGA tube guides did not make any difference in the functional recovery. By contrast, morphometric analysis showed that the introduction of N1E-115 cells inside PLGA 90:10 tube guides led to a significant lower number and size of regenerated nerve fibers, suggesting thus that this approach is not adequate for promoting peripheral nerve repair. Further studies are warranted to assess the role of other cellular systems as a foreseeable therapeutic strategy in peripheral nerve regeneration.

PLGA 90/10 and caprolactone biodegradable nerve guides for the reconstruction of the rat sciatic nerve.

The purpose of this study was to test in vivo two different nerve guides for promoting nerve regeneration across a 10-mm gap of the rat sciatic nerve: 1) one made of PLGA in a novel proportion (90:10) of the two polymers poly(L-lactide):poly(glycolide); 2) another made of (DL-lactide-epsilon-caprolactone) copolyester (Neurolac) tube, by comparing its healing efficacy with that of the more traditional methods of end-to-end nerve suture and autologous graft. Motor and sensory functional recovery were assessed throughout the healing period of 20 weeks, and the repaired nerves were processed for morphological and histomorphometrical analysis. Both motor and sensory functions improved significantly in all experimental nerve repaired groups. At the end of the 20-week follow-up, the end-to-end group showed better recovery of motor function when compared with the groups treated with guiding tubes. However, at this time point, the level of motor function in the Neurolac(R) and PLGA groups was similar to the one of the graft group. Nociception function also recovered faster in the end-to-end group compared with the Neurolac(R) and PLGA groups, and in this case, recovery was also delayed in the graft group. At the end of follow-up, nociception was similar in all experimental groups. Morphological and histomorphometrical analysis showed that axon regeneration occurred in both PLGA and Neurolac(R) experimental groups, with no significant differences in the total number of regenerated fibers, but disclosed a different pattern of degradation of the two types of tubes with larger biodegradation of PLGA material by the end of 20 weeks. These results suggest that both types of biomaterials are a good substrate for preparing tubular nerve guides, and their different pattern of degradation does not seem to influence the degree of nerve regeneration.

Evaluation of two biodegradable nerve guides for the reconstruction of the rat sciatic nerve.

The purpose of this study was to test in vivo two different nerve guides, one of PLGA made of a novel proportion (90:10) of the two polymers, Poly(L-lactide):Poly(glycolide), with (DL-lactide-epsilon-caprolactone) copolyester (Neurolac) tube, in promoting nerve regeneration across a 10 mm-gap of the rat sciatic nerve. Finally, end-to-end coaptation was performed. Motor and sensory functional recovery was assessed throughout the healing period of 20 weeks and the repaired nerves were processed for morphological analysis. Both motor and sensory functions improved significantly in all experimental nerve repair groups, although the rate and extent of recovery was significantly higher in the end-to-end group. No significant differences were detected in the comparison between the two types of tubes. Compatible with results of functional tests, morphological analysis showed that axon regeneration occurred in both PLGA and Neurolac experimental groups but disclosed a different pattern of degradation of the two types of tubes with larger biodegradation of PLGA material by the end of 20 weeks. These results suggest that both types of biomaterial are a good substrate for preparing tubular nerve guides and the different pattern of degradation does not seem to influence the degree of nerve regeneration.

Formação de professores: pequenas histórias, grandes personagens. Novas práticas e reconhecimento de novos saberes / Teacher training: small stories, great characters. New practices and recognition of new knowledge

O trabalho discute experiência em curso de formação universitária de professores. Permite reflexão sobre novo entendimento dos saberes oferecidos pela universidade, que alcançam alunos atuantes nas redes públicas e particular, em escolas de educação infantil e fundamental. No contexto atual, quando se discute o locus da formação - cursos de Pedagogia, institutos superiores de Educação e cursos normais médios - procura mostrar que a reflexão sobre tal formação ultrapassa o locus, alcançando o processo em si, envolvendo estratégias de formação do professor crítico-reflexivo. Ante a necessidade de oferecer a tais professores formação ampliada, mais importantes se tornam as contribuições à construção do ser, do saber e do fazer desse professor. A pesquisa apresenta-se como elemento integrador de dois focos de produção da realidade - pesquisador e pesquisados, validando estudos/resultados obtidos em construção coletiva do contexto que envolve a universidade e os espaços de atuação dos alunos-professores (AU)