Objectives. Emerging evidence of dysregulation of the myeloid cell compartment urges investigations on neutrophil characteristics in coronavirus disease 2019 . We isolated neutrophils from the blood of COVID-19 patients receiving general ward care and from patients hospitalised at intensive care units (ICUs) to explore the kinetics of circulating neutrophils and factors important for neutrophil migration and activation. Methods. Multicolour flow cytometry was exploited for the analysis of neutrophil differentiation and activation markers. Multiplex and ELISA technologies were used for the quantification of protease, protease inhibitor, chemokine and cytokine concentrations in
Peripheral nerve injuries severely impair patients' quality of life as full recovery is seldom achieved. Upon axonal disruption, the distal nerve stump undergoes fragmentation, and myelin breaks down; the subsequent regeneration progression is dependent on cell debris removal. In addition to tissue clearance, macrophages release angiogenic and neurotrophic factors that contribute to axon growth. Based on the importance of macrophages for nerve regeneration, especially during the initial response to injury, we treated mice with granulocyte-macrophage colony-stimulating factor (GM-CSF) at various intervals after sciatic nerve crushing. Sciatic nerves were histologically analyzed at different time intervals after injury for the presence of macrophages and indicators of regeneration. Functional recovery was followed by an automated walking track test. We found that GM-CSF potentiated early axon growth, as indicated by the enhanced expression of growth-associated protein at 7 days postinjury. Inducible nitric oxide synthase expression increased at the beginning and at the end of the regenerative process, suggesting that nitric oxide is involved in axon growth and pruning. As expected, GM-CSF treatment stimulated macrophage infiltration, which increased at 7 and 14 days; however, it did not improve myelin clearance. Instead, GM-CSF stimulated early brain-derived neurotrophic factor (BDNF) production, which peaked at 7 days. Locomotor recovery pattern was not improved by GM-CSF treatment. The present results suggest that GM-CSF may have beneficial effects on early axonal regeneration.
A decomposição da matéria orgânica é um processo natural de reciclagem que resulta na transformação de compostos orgânicos mais complexos em compostos inorgânicos que posteriormente serão reintegrados aos diferentes ciclos de vida de organismos. O presente estudo comparou a taxa de decomposição entre matérias orgânicas de origem vegetal e animal. Utilizamos 500g de folhas secas e 100g de carne de origem bovina, com 10 repetições cada. O material foi depositado em bolsas de confinamento ( litterbags ) e distribuído separadamente na área experimental, em contato com o solo. Nos dias 3, 7 e 21, as bolsas foram pesadas e a taxa de decomposição dos materiais foi quantificada medindo-se a massa remanescente. Verificamos que a taxa de decomposição de matéria orgânica animal é significativamente maior que a taxa de decomposição da matéria orgânica vegetal. Isso é explicado pela maior quantidade de proteínas, lipídeos e açúcares na matéria animal, os quais decompõem rapidamente, em comparação com a maior quantidade de celulose e ligninas no material vegetal, os quais decompõem vagarosamente.
Palavras-chave:Ciclagem de nutrientes, decomposição, litterbags
Dada a importância dos macrófagos durante a regeneração nervosa periférica, propomos administrar GM-CSF aos camundongos WT após o esmagamento do nervo, visando elevar a produção e o influxo de macrófagos no local da lesão e, consequentemente, acelerar a limpeza tecidual e a regeneração axonal. Zero, 24 e 48h após o esmagamento unilateral do nervo isquiático, camundongos C57BL/6 (M, 6-8 semanas) foram tratados com GM-CSF (50 ug/Kg, i.p.) ou PBS e sacrificados aos 3, 7, 14 ou 28 dias após a lesão, dal, (n=5/grupo/dia). A análise dos nervos se deu por imunomarcação de axônios e macrófagos; animais não lesionados foram utilizados como controle negativo (CN). A recuperação motora foi avaliada diariamente, via teste de marcha (sistema CatWalk). Observamos que não houve melhora na recuperação motora dos animais tratados com GM-CSF em comparação ao grupo controle, porém, em nível tecidual, o GM-CSF demonstra ser eficaz na antecipação do processo regenerativo axonal.
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