ABSTRACT
BACKGROUND: Intra-articular injections of local anesthetics are commonly used to enhance post-operative analgesia following orthopedic surgery as arthroscopic surgeries. Nevertheless, recent reports of severe complications due to the use of intra-articular local anesthetic have raised concerns. OBJECTIVES: The study aims to assess use of vitamin C in reducing adverse effects of the most commonly employed anesthetics - ropivacaine, bupivacaine and lidocaine - on human chondrocytes. METHODS: The chondrocyte viability following exposure to 0.5% bupivacaine or 0.75% ropivacaine or 1.0% lidocaine and/or vitamin C at doses 125, 250 and 500 µM was determined by LIVE/DEAD assay and annexin V staining. Expression levels of caspases 3 and 9 were assessed using antibodies by Western blotting. Flow cytometry was performed to analyze the generation of reactive oxygen species. RESULTS: On exposure to the local anesthetics, chondrotoxicity was found in the order ropivacaine < bupivacaine < lidocaine. Vitamin C effectively improved the reduced chondrocyte viability and decreased the raised apoptosis levels following exposure to anesthesia. At higher doses, vitamin C was found efficient in reducing the generation of reactive oxygen species and as well down-regulate the expressions of caspases 3 and 9. CONCLUSIONS: Vitamin C was observed to effectively protect chondrocytes against the toxic insult of local anesthetics ropivacaine, bupivacaine and lidocaine.
JUSTIFICATIVA: Injeções de anestésicos locais por via intra-articular são comumente usadas para melhorar a analgesia no período pós-operatório de cirurgia ortopédica como artroscopia. No entanto, relatos recentes de complicações graves devido ao uso de anestésico local por via intra-articular causou preocupações. OBJETIVOS: O objetivo do estudo foi avaliar o uso de vitamina C para reduzir os efeitos adversos dos anestésicos mais comumente usados (ropivocaína, bupivacaína e lidocaína) sobre condrócitos humanos. MÉTODOS: A viabilidade dos condrócitos após a exposição à bupivacaína a 0,5% ou ropivacaína a 0,75% ou lidocaína a 1,0% e/ou vitamina C em doses de 125, 250 e 500 µM foi determinada pelo ensaio Vivo/Morto e coloração com anexina V. Os níveis de expressão das caspases 3 e 9 foram avaliados com o uso de anticorpos pela técnica Western blotting. Citometria de fluxo foi feita para analisar a geração de espécies reativas ao oxigênio. RESULTADOS: Na exposição aos anestésicos locais, condrotoxicidade foi encontrada na seguinte ordem: ropivacaína < bupivacaína < lidocaína. A vitamina C efetivamente melhorou a redução da viabilidade dos condrócitos e diminuiu os níveis elevados de apoptose após a exposição à anestesia. Em doses mais altas, a vitamina C foi eficiente para reduzir a geração de espécies reativas ao oxigênio e assim regular negativamente a expressão das caspases 3 e 9. CONCLUSÕES: Observamos que a vitamina C foi eficaz na proteção dos condrócitos contra a agressão tóxica dos anestésicos locais ropivacaína, bupivacaína e lidocaína.
Subject(s)
Humans , Ascorbic Acid/pharmacology , Reactive Oxygen Species/metabolism , Chondrocytes/drug effects , Anesthetics, Local/toxicity , Ascorbic Acid/administration & dosage , Bupivacaine/toxicity , Down-Regulation/drug effects , Cells, Cultured , Apoptosis/drug effects , Chondrocytes/pathology , Dose-Response Relationship, Drug , Caspase 3/genetics , Caspase 9/genetics , Flow Cytometry , Ropivacaine , Amides/toxicity , Lidocaine/toxicity , Antioxidants/administration & dosage , Antioxidants/pharmacologyABSTRACT
Gastric cancer is the most prevalent cancer with poor survival in gastrointestinal tract. Caspase 3 and 9 play an important role in the development and progression of cancer. Polymorphisms in the genes for these enzymes can affect gene activity and thus may influence susceptibility to gastric cancer. In this study, caspase 3 and 9 genes polymorphisms in patients with gastric cancer were examined. In a case - control study, 100 patients with gastric cancer and 100 healthy individuals were evaluated in the region rs4647601: G> T for caspase-3 and -1263 A> G gene promoter for caspase 9. DNA extraction was performed from whole blood according to manufacture protocol. RFLP-PCR method was carrying out for detection of caspase 3 and 9 genes genotype in two groups. In this study, 143 men and 57 women were evaluated. All of them were selected from the same race and geographical area. The results indicated an increase of the mutant G allele in the control group, which leads to a decreasing in the incidence of gastric cancer [P<0.0001, OR: 0.096, [%0.95CL] =0.04-0.23]. It seems that screening of -1263 A> caspase 9 polymorphism could be a useful marker in personal sensitivity to gastric cancer and help to cancer treatment and prevention process. It is concluded that caspase gene variation may be a diagnostic factor in the gastric cancer.
Subject(s)
Humans , Male , Female , Caspase 3/genetics , Caspase 9/genetics , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Stomach Neoplasms/enzymology , Polymorphism, Restriction Fragment Length , Polymerase Chain ReactionABSTRACT
The effectiveness of the caspase-9-based artificial "death switch" as a safety measure for gene therapy based on the erythropoietin (Epo) hormone was tested in vitro and in vivo using the chemical inducer of dimerization, AP20187. Plasmids encoding the dimeric murine Epo, the tetracycline-controlled transactivator and inducible caspase 9 (ptet-mEpoD, ptet-tTAk and pSH1/Sn-E-Fv-Fvls-casp9-E, respectively) were used in this study. AP20187 induced apoptosis of iCasp9-modified C2C12 myoblasts. In vivo, two groups of male C57BI/6 mice, 8-12 weeks old, were injected intramuscularly with 5 µg/50 g ptet-mEpoD and 0.5 µg/50 g ptet-tTAk. There were 20 animals in group 1 and 36 animals in group 2. Animals from group 2 were also injected with the 6 µg/50 g iCasp9 plasmid. Seventy percent of the animals showed an increase in hematocrit of more than 65 percent for more than 15 weeks. AP20187 administration significantly reduced hematocrit and plasma Epo levels in 30 percent of the animals belonging to group 2. TUNEL-positive cells were detected in the muscle of at least 50 percent of the animals treated with AP20187. Doxycycline administration was efficient in controlling Epo secretion in both groups. We conclude that inducible caspase 9 did not interfere with gene transfer, gene expression or tetracycline control and may be used as a safety mechanism for gene therapy. However, more studies are necessary to improve the efficacy of this technique, for example, the use of lentivirus vector.