Investigating the effect of intracameral cefuroxime on oxidative stress and apoptosis in the rat cornea / Investigando o efeito de cefuroxima intracameral sobre o estresse oxidativo e a apoptose na córnea de ratos

ABSTRACT PURPOSE: We examined the effect of intracameral administration of cefuroxime on oxidative stress and endothelial apoptosis in rat corneal tissue. METHODS: In total, 30 rats were divided into 3 groups of 10 rats each (intracameral administration of cefuroxime 0.1 mg/0.01 mL (cefuroxime group); intracameral administration of balanced salt solution 0.01 mL (control group); or absence of intracameral injection (sham group). Corneal endothelial apoptosis was assessed by immunohistochemical analysis using caspase-3 and caspase-8. Total oxidant status, total antioxidant status, oxidative stress index, and paraoxonase and arylesterase levels were examined in corneal endothelial tissue and serum. RESULTS: Paraoxonase levels in the serum were significantly different between the sham and cefuroxime groups (p=0.027). A significant difference was also observed in total oxidant status levels between the cefuroxime and balanced salt solution groups (p=0.023). In addition, there were significant differences in total antioxidant status levels in corneal tissue between the cefuroxime and sham groups (p<0.001) and between the cefuroxime and balanced salt solution groups (p<0.001). Furthermore, significant differences were also observed in oxidative stress index levels between the cefuroxime and balanced salt solution groups (p=0.001) and between the cefuroxime and sham groups (p=0.026). According to the immunohistochemical staining results, a significant association with caspase-3 activity existed between the cefuroxime and balanced salt solution groups (p=0.007), while no significant difference was found with caspase-8 activity (p=0.541). Caspase-3 activity exhibited a significant relationship between the sham and balanced salt solution groups (p=0.018), but no relationship was found with caspase-8 activity (p=0.623). CONCLUSION: Immunohistochemical examination revealed that intracameral cefuroxime increased apoptosis when compared to the sham and balanced salt solution groups. Moreover, intracameral cefuroxime increased oxidative stress in the cornea and simultaneously induced apoptosis.

RESUMO OBJETIVO: Examinamos o efeito da administração intracameral da cefuroxima sobre o estresse oxidativo e a apoptose endotelial no tecido corneano de ratos. MÉTODOS: No total, 30 ratos foram divididos em 3 grupos de 10 ratos cada (administração intracameral de cefuroxima 0,1 mg/0,01 mL (grupo cefuroxima), administração intracameral de solução salina balanceada 0,01 mL (grupo controle) ou ausência de injeção intracameral (grupo sham)). A apoptose endotelial da córnea foi avaliada por análise imuno-histoquimica usando caspase-3 e -8. O status oxidante total, o status antioxidante total, o índice de estresse oxidativo e os níveis de a paraoxonase e arilesterase foram investigados no tecido endotelial da córnea e no soro. RESULTADOS: Os níveis de paraoxonase no soro foram significativamente diferentes entre os grupos sham e cefuroxima (p=0,027). Foi também observada uma diferença significativa nos níveis de estado oxidante total entre os grupos cefuroxima e solução salina balanceada (p=0,023). Além disso, houve diferenças significativas nos níveis de status antioxidante total no tecido da córnea entre os grupos cefuroxima e sham (p<0,001) e entre os grupos cefuroxima e solução salina balanceada (p<0,001). Diferenças significativas também foram observadas nos níveis do índice de estresse oxidativo entre os grupos cefuroxima e solução salina balanceada (p=0,001) e entre os grupos cefuroxima e sham (p=0,026). De acordo com os resultados de coloração imuno-histoquimica, houve associação significativa com a atividade da caspase-3 entre os grupos cefuroxima e solução salina balanceada (p=0,007), enquanto não houve diferença significativa com a atividade da caspase-8 (p=0,541). A atividade da caspase-3 exibiu uma relação significativa entre os grupos sham e solução salina balanceada (p=0,018), mas nenhuma relação foi encontrada com a atividade da caspase-8 (p=0,623). CONCLUSÃO: O exame imuno-histoquímico revelou que a cefuroxima intracameral aumentou a apoptose quando comparada com os grupos sham e solução salina balanceada. Além disso, a cefuroxima intracameral aumentou o estresse oxidativo na córnea e induziu simultaneamente a apoptose.

Association between paraoxonase 1 (PON1) enzyme activity, PON1 C(−107)T polymorphism, nutritional status, and lipid profile in children

BACKGROUND: Paraoxonase 1 (PON1) is an enzyme that possesses anti-atherogenic and anti-inflammatory properties with serum levels determined by genetic and exogenous factors. Lower serum PON1 arylesterase activity is associated to metabolic alterations related to childhood overweight and onset and/or development of diabetes and CVD later in life. However, data on the relationship between genetic PON1 polymorphisms and nutritional status as well as lipid profile in children are limited. To investigate the distribution of the C(−107)T PON1 gene polymorphism and its relation with serum PON1 enzyme activity, nutritional status and lipid profile in children. METHODS: A cross-sectional study was performed including 73 children aged 5 to 7 years who attended public pediatric clinics. PON1 C(−107)T, arylesterase activity, body mass index for the age, and serum lipid profile were evaluated. RESULTS: PON1 activity was higher in overweight children compared to the normal weight ones (p= 0.02). The genotypic frequency did not differ between the two groups (p> 0.05). Carriers of CC genotype had higher enzyme activity than T allele carriers, and this difference was greater among normal weight children. HDL levels were higher among normal weight children carrying CC genotype, compared to those carrying the T allele (p< 0.01).CONCLUSION: The PON1 C(−107)T polymorphism is associated with higher serum enzyme activity in children, as observed previously in adults. In addition, this polymorphism also shows association to higher high density lipoprotein (HDL) levels and serum PON1 arylesterase activity in the normal weight children studied.

Correlation between the serum and tissue levels of oxidative stress markers and the extent of inflammation in acute appendicitis

OBJECTIVES: To determine the serum and tissue levels of markers of impaired oxidative metabolism and correlate these levels with the histopathology and Alvarado score of acute appendicitis patients. METHOD: Sixty-five acute appendicitis patients (mean age, 31.4±12.06 years; male/female, 30/35) and 30 healthy control subjects were studied. The Alvarado score was recorded. Serum samples were obtained before surgery and 12 hours postoperatively to examine the total antioxidant status, total oxidant status, paraoxonase, stimulated paraoxonase, arylesterase, catalase, myeloperoxidase, ceruloplasmin, oxidative stress markers (advanced oxidized protein products and total thiol level) and ischemia-modified albumin. Surgical specimens were also evaluated. RESULTS: The diagnoses were acute appendicitis (n = 37), perforated appendicitis (n = 8), phlegmonous appendicitis (n = 12), perforated+phlegmonous appendicitis (n = 4), or no appendicitis (n = 4). The Alvarado score of the acute appendicitis group was significantly lower than that of the perforated+phlegmonous appendicitis group (p = 0.004). The serum total antioxidant status, total thiol level, advanced oxidized protein products, total oxidant status, catalase, arylesterase, and ischemia-modified albumin levels were significantly different between the acute appendicitis and control groups. There was no correlation between the pathological extent of acute appendicitis and the tissue levels of the markers; additionally, there was no correlation between the tissue and serum levels of any of the parameters. CONCLUSIONS: The imbalance of oxidant/antioxidant systems plays a role in the pathogenesis acute appendicitis. The Alvarado score can successfully predict the presence and extent of acute appendicitis. .