In vitro immunogenic profile of recombinant SARS-CoV2 S1-RBD peptide in murine macrophage and microglial cells

BACKGROUND The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants can infect common mice inducing significant pathological lung lesions and inflammatory responses. This substantially mimics coronavirus disease 19 (COVID-19) infection and pathogenesis in humans. OBJECTIVES To characterise the effects of recombinant SARS-CoV-2 S1 receptor-binding domain (RBD) peptide in murine macrophage and microglial cells' immune activation compared with classical PAMPs in vitro. METHODS Murine RAW 264.7 macrophages and BV2 microglial cells were exposed to increasing concentrations of the RBD peptide (0.01, 0.05, and 0.1 µg/mL), Lipopolysaccharide (LPS) and Poly(I:C) and evaluated after two and 24 h for significant markers of macrophage activation. We determined the effects of RBD peptide on cell viability, cleaved caspase 3 expressions, and nuclear morphometry analysis. FINDINGS In RAW cells, RBD peptide was cytotoxic, but not for BV2 cells. RAW cells presented increased arginase activity and IL-10 production; however, BV2 cells expressed iNOS and IL-6 after RBD peptide exposure. In addition, RAW cells increased cleaved-caspase-3, apoptosis, and mitotic catastrophe after RBD peptide stimulation but not BV2 cells. CONCLUSION RBD peptide exposure has different effects depending on the cell line, exposure time, and concentration. This study brings new evidence about the immunogenic profile of RBD in macrophage and microglial cells, advancing the understanding of SARS-Cov2 immuno- and neuropathology.

Sugarcane biopolymer as a guide tube in the regeneration of peripheral nerves in rats / Biopolímero de caña de azúcar como tubo guía en la regeneración de nervios periféricos en ratones

SUMMARY: Peripheral nerve regeneration is a serious clinical problem. The goal of this work was to evaluate comparatively a biopolymer tube of sugarcane with an expanded polyethylene tube as a tube guide in peripheral nerve regeneration. Fourteen male albino Wistar rats were used, separated into three different groups: control (CG), lesion + polyethylene tube (PG) and lesion + sugarcane biopolymer (SBG). At 60 days old, animals from the PG and SBG underwent surgery for tubulization of the sciatic nerve, and 60 days after the injury they were sacrificed for collection of the nerve. In the analysis of the number of nerve fibers, a smaller number was seen in the PG and SBG groups compared to the CG, no difference was seen between the PG and SBG groups (p<0.05). With regard to the number of blood vessels, the SBG group had a larger number than the CG and PG groups (p<0.05). The SBG also presented increase on axonal diameter and G -ratio compared to PG (p<0.05). Taken together these data revealed that biopolymer tube favors a suitable environment for peripheral nerve regeneration.

RESUMEN: La regeneración nerviosa periférica es un problema clínico grave. El objetivo de este trabajo fue evaluar comparativamente un tubo de biopolímero de caña de azúcar con un tubo de polietileno expandido, como guía de tubo en la regeneración de nervios periféricos. Se utilizaron dieciocho ratas Wistar albinas macho, separadas en tres grupos: control (CG), lesión + tubo de polietileno (PG) y lesión + biopolímero de caña de azúcar (SBG). A los 60 días de edad, los animales del PG y SBG fueron sometidos a una cirugía para la tubulización del nervio ciático, y 60 días después de la lesión fueron sacrificados para la recolección del nervio. En el análisis del número de fibras nerviosas, se observó un número menor en los grupos PG y SBG en comparación con el CG; no se observaron diferencias entre los grupos PG y SBG (p <0,05). Con respecto al número de vasos sanguíneos, el grupo SBG tuvo un número mayor que los grupos CG y PG (p <0,05). El SBG también presentó un aumento en el diámetro axonal y la proporción G en comparación con PG (p <0,05). En conjunto, estos datos revelaron que el tubo de biopolímero favorece un entorno adecuado para la regeneración de nervios periféricos.

Regenerative capacity and histomorphometric changes in rat sciatic nerve following experimental neurotmesis / Capacidad regenerativa y cambios histomorfométricos en el nervio ciático de ratas luego de una neurotmesis experimental

Through a wide range of cellular and molecular events, the peripheral nervous system is endowed with great regenerative capacity, responding immediately to injuries that occur along the length of the nerve. The aim of this study was to histomorphometrically assess the degree of maturity of the nervous tissue and possible microscopic changes in newly formed nerve segments 60 days after experimental neurotmesis of the sciatic nerve in rats. Control Group (CG) and an Injury Group (IG) were used. IG underwent neurotmesis of the sciatic nerve of the right foot, with immediate surgical repair using the tubulization technique. 60 days following experimental surgery, animals from both groups had their sciatic nerves collected for histomorphometric analysis. Statistical analysis was performed, using the Student t-test for independent samples, expressed as mean ± standard deviation, with 5% significance. In the event of injury, peripheral nerve tissue is mobilized in an intrinsic self-healing process. 60 days following of nerve regeneration in neurotmesis injury, the peripheral nerve presents a segment joining the newly formed neural stump. The new stump has a number of regenerated axons compatible with an intact nerve, but which still show great immaturity in the axonal structural layers of the nerve.

Mediante diversos procesos celulares y moleculares, el sistema nervioso periférico tiene una gran capacidad regenerativa, respondiendo inmediatamente a las lesiones ocurridas a lo largo de su extensión. El objetivo de este estudio fue evaluar histomorfométricamente el grado de madurez del tejido nervioso y los posibles cambios microscópicos en los segmentos nerviosos recién formados 60 días después de la neurotmesis experimental en el nervio ciático de ratas. Se utilizaron 9 ratas (Wistar) separadas en grupo control (GC, n= 4) y Grupo lesión (GL, n= 5). A los 60 días de vida, el grupo GL fue sometido a neurotmesis del nervio ciático de la miembro posterior derecho, con inmediata corección quirúrgica con la técnica de tubolización. Completados 60 días luego de la cirugía experimental, los animales de ambos grupos fueron anestesiados y sus nervios ciáticos seccionados para el análisis histomorfométrico. Se realizó un análisis estadístico utilizando la prueba t de Student para muestras independientes, expresado como media ± desviación estándar, con un 5% de significancia. A los 60 días de la lesión por neurotmesis, el nervio ciático del GL presentó alteraciones histomorfométricas significativas para las variables: número de vasa nevorum, densidad de fibras mielínicas, diámetro axonal y de fibras mielínicas, espesor de la vaina de mielina y razón G, con similitud solamente para los números absolutos de fibras mielínicas regeneradas. El nervio periférico durante su proceso regenerativo, pasa por grandes alteraciones estructurales, siguiendo una secuencia coordinada de acciones, que dependiendo de las condiciones del microambiente donde ocurre esta regeneración, podrá ser clave para el nivel de regenerecion nerviosa periférica.

The effectiveness of biofeedback in treatment of women with stress urinary incontinence: a systematic review / Eficácia do biofeedback no tratamento de mulheres com incontinência urinária de esforço: revisão sistemática

OBJECTIVES: to assess whether pelvic-floor muscle training associated with biofeedback is more effective in the treatment of women with stress urinary incontinence, when compared to exercise alone. METHODS: a research of articles published in the last 20 years in Lilacs, PubMed and SCIRUS databases, using the descriptors urinary incontinence, stress and biofeedback was conducted. Randomized clinical trials comparing pelvic-floor muscle training with and without biofeedback were included. RESULTS: the study involved three randomized clinical trials involving 169 patients. A physical therapist was responsible for conducting the treatment using electromyographic or pressure biofeedback, and exercises were performed in the clinic or at home. The assessment methods, treatment times and protocols used were heterogeneous. Statistical analysis and rates of cure/improvement were similar between the groups of articles analyzed. Two studies had a score 8, and the third had 6 points according to PEDro's Scale. CONCLUSIONS: examination of the studies found suggests that adding biofeedback to pelvic-floor muscle training appears not to bring about a significant difference in terms of the success of treatment, when compared to perineal exercises performed in isolation.

OBJETIVOS: verificar se os exercícios para a musculatura do assoalho pélvico (MAP) associados ao biofeedback promovem maior eficácia no tratamento da incontinência urinária de esforço em mulheres, quando comparados a cinesioterapia de forma isolada. MÉTODOS: foi realizada uma pesquisa dos artigos publicados nos últimos 20 anos, nas bases de dados Lilacs, PubMed e SCIRUS, através dos descritores urinary incontinence, stress e biofeedback. Foram incluídos ensaios clínicos aleatorizados que utilizaram como intervenção exercícios para a MAP isolados e associados ao biofeedback, de forma comparativa. RESULTADOS: foram incluídos três ensaios clínicos randomizados envolvendo 169 pacientes. O fisioterapeuta foi responsável por conduzir o tratamento utilizando biofeedback eletromiográfico ou pressórico, e os exercícios foram realizados no ambulatório ou orientados para casa. Verificou-se heterogeneidade quanto ao método de avaliação, tempo de tratamento e protocolos utilizados. As análises estatísticas e os índices de cura/melhora foram semelhantes entre os grupos dos artigos analisados. Dois estudos obtiveram pontuação igual a oito e o terceiro alcançou seis pontos de acordo com a Escala PEDro. CONCLUSÕES: a análise dos estudos encontrados sugere que a adição do biofeedback aos exercícios perineais parece não promover diferença significativa para o sucesso do tratamento, quando comparado aos exercícios perineais realizados de forma isolada.