VEGF121 como Mediador de Efeitos Cardioprotetores Pós-Hipóxia via CaSR e via da Protease Dependente de Mitocôndria / VEGF121 Mediates Post-Hypoxia Cardioprotective Effects Via CaSR and Mitochondria-Dependent Protease Pathway

Resumo Fundamento: A doença cardiovascular é a principal causa de morte em todo o mundo. A apoptose mediada por hipóxia em cardiomiócitos é uma das principais causas de distúrbios cardiovasculares. O tratamento com a proteína do fator de crescimento endotelial vascular (VEGF, do inglês vascular endothelial growth factor) foi testado, mas as dificuldades operacionais limitaram seu uso. Entretanto, com os avanços da terapia gênica, aumentou o interesse na terapia gênica baseada no VEGF em doenças cardiovasculares. No entanto, o mecanismo preciso pelo qual a reposição de VEGF resgata os danos pós-hipóxia em cardiomiócitos não é conhecido. Objetivos: Investigar o efeito da expressão de VEGF121 pós-hipóxia utilizando cardiomiócitos de ratos neonatos. Métodos: Cardiomiócitos isolados de ratos neonatos foram utilizados para estabelecer um modelo in vitro de lesão cardíaca induzida por hipóxia. O efeito da superexpressão de VEGF, isolado ou em conjunto com inibidores de moléculas pequenas que têm como alvo os canais de cálcio, receptores sensíveis ao cálcio (CaSR, do inglês calcium-sensitive receptors) e calpaína, no crescimento e proliferação celular em lesão de cardiomiócitos induzidos por hipóxia, foram determinados com ensaio de MTT, coloração TUNEL, coloração com Anexina V/PI, lactato desidrogenase e atividade da caspase. Para análise estatística, um valor de p<0,05 foi considerado significativo. Resultados: Verificou-se que o efeito do VEGF121 foi mediado por CaSR e calpaína, mas não foi dependente dos canais de cálcio. Conclusões: Nossos resultados, mesmo em um ambiente in vitro, estabelecem as bases para uma validação futura e testes pré-clínicos da terapia gênica baseada em VEGF em doenças cardiovasculares.

Abstract Background: Cardiovascular disease is the major cause of death worldwide. Hypoxia-mediated apoptosis in cardiomyocytes is a major cause of cardiovascular disorders. Treatment with vascular endothelial growth factor (VEGF) protein has been tested but operational difficulties have limited its use. However, with the advancements of gene therapy, interest has risen in VEGF-based gene therapy in cardiovascular disorders. However, the precise mechanism by which VEGF replenishment rescues post-hypoxia damage in cardiomyocytes is not known. Objectives: To investigate the effect of post-hypoxia VEGF121 expression using neonatal rat cardiomyocytes. Methods: Cardiomyocytes isolated from neonatal rats were used to establish an in vitro model of hypoxia-induced cardiac injury. The effect of VEGF overexpression, alone or in combination with small-molecule inhibitors targeting calcium channel, calcium sensitive receptors (CaSR), and calpain on cell growth and proliferation on hypoxia-induced cardiomyocyte injury were determined using an MTT assay, TUNEL staining, Annexin V/PI staining, lactate dehydrogenase and caspase activity. For statistical analysis, a value of P<0.05 was considered to be significant. Results: The effect of VEGF121 was found to be mediated by CaSR and calpain but was not dependent on calcium channels. Conclusions: Our findings, even though using an in vitro setting, lay the foundation for future validation and pre-clinical testing of VEGF-based gene therapy in cardiovascular diseases.

Ilizarov technique in treatment of Gustilo type Ⅲ B and C of large tibia bone defect combined with soft tissue defect / 局解手术学杂志

Objective To investigate the efficacy of Ilizarov technique in treatment of Gustilo type Ⅲ B and C of large tibia bone defect combined with soft tissue defect. Methods Thirty cases with large tibia bone defect combined with soft tissue defect in our hospital from January 2016 to December 2018 were selected including 25 cases with type Ⅲ B and 5 cases with type Ⅲ C,who were all open tibia fractures and treated with Ilizarov technique. Results All patients were followed up for 10 to 18 months with an average of 15 months. The bone defects were reconstructed, the difference between the length of the affected limb and the healthy side was less than 2 cm. The fracture was healed and the wound was closed. One case was with paralysis of common peroneal nerve and recoveried after 3 months. Twenty-two cases recovered without extra surgery, five cases restored with skin graft and three cases covered the wound by rotating skin flap. Conclusion Ilizarov technique is one of effective ways to treat Gustilo Ⅲ type B and type C of large defect combined with soft tissue defect.

Isolation, Purification and Characterization of Human Serum Apolipoprotein A Ⅰ / 中国基层医药

Objective To explore a method to separate and purify apolipoprotein Ⅰ from human serum conveniently and efficiently. Methods Apolipoprotein Ⅰ was separated and pufified by ultracentrifugation and affinity chromatography. Then the purified apolipoprotein Ⅰ was analyzed by SDS-polyacrylamide gel electrophoresis and agar gel double immunodiffusion test. Results The purified apolipoprotein Ⅰ was satisfactory. Conclusion This method had good reliability and was convenient and economical.