Tibial and fibular nerves evaluation using intraoperative electromyography in rats

ABSTRACT PURPOSE: To evaluate a new model of intraoperative electromyographic (EMG) assessment of the tibial and fibular nerves, and its respectives motor units in rats. METHODS: Eight Wistar rats underwent intraoperative EMG on both hind limbs at two different moments: week 0 and week 12. Supramaximal electrical stimulation applied on sciatic nerve, and compound muscle action potential recorded on the gastrocnemius muscle (GM) and the extensor digitorum longus muscle (EDLM) through electrodes at specifics points. Motor function assessment was performaced through Walking Track Test. RESULTS: Exposing the muscles and nerves for examination did not alter tibial (p=0.918) or fibular (p=0.877) function between the evaluation moments. Electromyography of the GM, innervated by the tibial nerve, revealed similar amplitude (p=0.069) and latency (p=0.256) at week 0 and at 12 weeks, creating a standard of normality. Meanwhile, electromyography of the EDLM, innervated by the fibular nerve, showed significant differences between the amplitudes (p=0.003) and latencies (p=0.021) at the two different moments of observation. CONCLUSION: Intraoperative electromyography determined and quantified gastrocnemius muscle motor unit integrity, innervated by tibial nerve. Although this study was not useful to, objectively, assess extensor digitorum longus muscle motor unit, innervated by fibular nerve.

Combined polyglycolic acid tube and autografting versus autografting or polyglycolic acid tube alone. A comparative study of peripheral nerve regeneration in rats

PURPOSE: To compare sciatic nerve regeneration in rats using three different techniques of repair. METHODS: Fifteen isogonics rats were divided into three groups according to the method used to repair a 5-mm long defect created in the sciatic nerve: autogenous graft (Group A), polyglycolic acid tube (PGAt) (Group B), and of the association of PGAt with the graft (Group C). Histological analysis, regenerated myelinated axon number count and functional analysis were used to compare after six weeks. RESULTS: There was no difference in fiber diameter and degree of myelinization presented by Groups A, B and C. Group B presented the lowest number of regenerated axons. The groups did not display any significant functional difference after walking track analysis (p<0.05). CONCLUSION: No differences between the three groups in terms of functional recovery, although there were histological differences among them. .

Influência da adição de células-tronco mesenquimais derivadas de tecido adiposo associadas a conduto de fibrina na regeneração de nervo periférico em modelo experimental de ratos / Influence of the addition of adipose derived stem cell in fibrin conduit for peripheral nerve regeneration in a rat model

INTRODUÇÃO: O tratamento padrão para lesões de nervo periférico que não podem ser suturados primariamente é a enxertia de nervo autólogo. Esse método, porém, carece de resultados satisfatórios e impõe algumas limitações técnicas e complicações. Várias opções já foram estudadas como alternativas ao enxerto de nervo, porém ainda não há conduto biológico ou sintético disponível para uso clínico que tenha a mesma capacidade regenerativa do enxerto de nervo autólogo. Os avanços em cultura celular e o maior entendimento dos mecanismos moleculares e celulares da regeneração nervosa levaram ao uso de células promotoras de regeneração associado aos condutos na tentativa de melhorar os resultados da reconstrução nervosa. Vários estudos demonstraram que o uso de célulastronco derivadas de tecido adiposo (ADSC) em condutos aloplásticos potencializa a regeneração neural. No entanto, nenhum estudo até hoje comparou a adição de ADSC indiferenciadas em conduto aloplástico ao tratamento padrão com autoenxerto. Esse estudo tem como objetivo avaliar a influência da adição de células-tronco mesenquimais derivadas de tecido adiposo em conduto de fibrina na regeneração de nervo periférico e comparar com enxertia de nervo autógeno em modelo experimental de ratos. MÉTODO: Em um modelo de lesão de nervo ciático (defeito de 10 mm) foram avaliados 30 ratos Wistar divididos em 3 grupos. O defeito de nervo foi reconstruído usando conduto de fibrina (Grupo Conduto, n=10), conduto de fibrina acrescido de ADSC (Grupo ADSC, n=10) e autoenxerto do nervo (Grupo Autoenxerto, n=10). A avaliação funcional dos ratos foi realizada com o teste de marcha (walking track analysis) com 4, 8 e 12 semanas e o índice de função ciática (IFC) foi determinado. Após 12 semanas, o peso do músculo tríceps sural foi avaliado. Segmentos dos nervos regenerados também foram coletados para análises histológicas como densidade axonal e diâmetro médio das fibras. RESULTADOS: O grupo Conduto mostrou recuperação...

Introduction: The standard treatment for peripheral nerve injuries that cannot be primarily sutured is nerve autograft. But this method lacks satisfactory results and imposes some technical limitations and complications. Several options have been studied as alternatives to nerve autografting, but there is no biological or synthetic conduit available for clinical use that provides the same regenerative capacity of nerve autograft. Advances in cell culture and understanding of nerve regeneration mechanisms led to the use of regeneration-inducing cells in association with conduits, in an attempt to improve the reconstruction results. Several studies have shown that the use of adipose derived stem cells (ADSC) into conduits enhances neural regeneration. However, there is no study that compared the addition of undifferentiated ADSC in alloplastic conduit to standard treatment with autograft. This study evaluated the influence of the addition of adipose derived stem cell in fibrin conduit for peripheral nerve regeneration in comparison to the nerve autograft, in a rat model. Method: A sciatic nerve injury model (10-mm defect) was performed in 30 Wistar rats, which were divided into 3 groups. Nerve defect was reconstructed using fibrin conduit (Conduit group, n=10), fibrin conduit filled with ADSC (ADSC group, n = 10) and nerve autograft, (Autograft group, n=10). The walking behavior was measured by footprint analysis at 4, 8, and 12 weeks and sciatic function index (SFI) was determined. After 12 weeks, the triceps surae muscle weight was evaluated and histological analysis was performed to evaluate the regenerated nerve and measured axonal density and fibers diameter average. Results: The Conduit group showed less improvement in walking behavior compared to ADSC group and Autograft group (SFI at 12 weeks, - 53.3 ± .3 vs -44.7 ± 3 vs -35.6 ± 2 respectively, p< 0.001). The triceps surae muscle weight ratio of the fibrin conduit group was 41.1± 3%, ADSC group was...

Análise morfométrica do lábio superior e da ação do envelhecimento / Morphometric analysis of the upper lip and the action of ageing

A pleasant smile depends on harmonious relationships between the teeth, gums, and lips. The present study measured upper lip changes related to ageing using a morphometric analysis. Methods: Forty six Caucasian women at least 15 years of age were selected and divided into four groups: 15 - 30 years old, 31 - 45 years old, 46 - 60 years old, and > 60 years old. Frontal photographs with closed lips and parted lips were taken. The following measurements were performed: upper lip height, upper vermilion height in parted and closed lips positions, and exposure of the central upper incisors in the relaxed position. Results: Upper lip height increased with age. The average upper lip height in the closed lips position was 13.75 mm in the youngest age-range (15 - 30 years old). The upper lip height gradually increased with age until reaching an average of 19.24 mm was observed in the > 60 years old group. The opposite result was observed in upper vermilion height, which decreased with increasing age. The average vermilion height in the parted lips position was 7.09 mm in the youngest age-range (15-30 years old) and decreased to 4.58 mm in the oldest group (> 60 years old). Teeth exposure decreased with age. The average upper teeth exposure was 3.55 mm in the youngest group and decreased to 0.40 mm in the oldest group. Conclusion: The upper lip height increases, while the upper vermilion height and exposure of the upper teeth decrease with age...

Um sorriso considerado agradável envolve relações harmônicas entre os dentes, gengivas e lábios. O presente estudo mediu as alterações no lábio superior, relacionadas ao envelhecimento, utilizando análise morfométrica. Método: Foram selecionadas 46 mulheres caucasianas com idade mínima de 15 anos e divididas em quatro grupos: 15-30 anos, 31-45 anos, 46-60 anos e > 60 anos. Foram tiradas fotografias frontais com a boca fechada e na posição de repouso. As seguintes medidas foram realizadas: altura do lábio superior, altura do vermelhão do lábio superior nas posições repouso e fechada, e exposição dos dentes incisivos superiores centrais na posição repouso. Resultados: A altura do lábio superior aumentou com a idade. A média da altura do lábio superior com a boca fechada foi 13,75 mm na faixa etária mais nova (15-30 anos). A altura do lábio superior gradualmente aumenta com a idade até atingir uma média de 19,24 mm, observada no grupo > 60 anos. O resultado oposto foi observado na altura do vermelhão superior, que diminuiu com o aumento da idade. A altura média do vermelhão com a boca em repouso foi 7,09 mm na faixa etária mais nova (15-30 anos) e diminuiu para 4,58 mm no grupo mais velho (> 60 anos). A exposição dos dentes diminuiu com a idade. A exposição média dos dentes superiores foi de 3,55 mm no grupo mais jovem e diminuiu para 0.40 mm no grupo mais velho. Conclusão: A altura do lábio superior aumenta, enquanto a altura do vermelhão superior e a exposição dos dentes superiores diminuem com a idade...