Effects of extracellular signal-regulated kinase inhibition by AG126 on tissue tumor necrosis factor-alpha expression and multiple organ dysfunction in rats with postburn Staphylococcus aureus sepsis / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of extracellular signal-regulated kinase (ERKs) inhibition by AG126 on tissue tumor necrosis factor-alpha (TNF-alpha) expression and multiple organ dysfunction in rats with postburn Staphylococcus aureus sepsis and its potential signal regulating mechanism.</p><p><b>METHODS</b>To reproduce postburn sepsis model, male Wistar rats were inflicated with 20% total body surface area third-degree scald followed by Staphylococcus aureus challenge. 34 rats were randomly divided into four groups as follows: normal control group (n = 6), scald control group (n = 6), postburn sepsis group (n = 12), and AG126 treatment group (n = 10). Tissue samples from the liver, kidneys and lungs were collected to determine phosphorylated ERKs by Western blot analysis, and TNF-alpha mRNA expression as well as its protein levels.</p><p><b>RESULTS</b>It was revealed that phosphorylated ERKs in the liver, lungs, and kidneys from postburn septic animals were up-regulated rapidly at 0.5 - 2.0 hours, being 1.94-fold (P < 0.05), 2.86-fold (P < 0.01), and 1.41-fold at 2.0 hours compared to normal controls, respectively. Treatment with AG126 could significantly reduce phosphorylated ERKs in lung tissue by 70.6% (P < 0.01) at 2.0 hours postburn sepsis, and almost completely inhibited ERKs activation in the liver and kidneys at various time points. Meanwhile, both TNF-alpha mRNA and protein expressions in the liver, lungs, and kidneys were significantly decreased in AG126-treated group following septic challenge (P < 0.05 or 0.01). In addition, 2.0 hours after Staphylococcus aureus infection, treatment with AG126 markedly improved hepatic and renal function parameters, including serum ALT, AST, Cr, as well as BUN levels (P < 0.05 or 0.01), together with significant decrease in pulmonary myeloperoxidase activity, compared to those without AG126 treatment.</p><p><b>CONCLUSION</b>These data suggested that ERKs signal transduction might be involved in the pathogenesis of systemic inflammatory response and multiple organ dysfunction in postburn gram-positive bacterial sepsis. Early treatment with AG126 could significantly down-regulate TNF-alpha mRNA expression as well as protein levels in vital organs and attenuate multiple organ dysfunction induced by scald injury combined with Staphylococcus aureus challenge.</p>

Analysis on 60 Pollution Accidents of Municipal Water Distribution Network and Secondary Water Supply System / 环境与健康杂志

To understand the characteristics and causes of the pollution accidents of municipal water distribution network and secondary water supply system.Data on the pollution accidents of municipal water distribution network and secondary water supply system having occurred in recent 20 years were collected and analyzed. The main pollution type of municipal water distribution network and secondary water supply system was biological pollution,the amount of which took 73.3% of the total accidents.The pollution accidents mainly occured in schools or colleges and residential buildings offered by some enterprises to their members and families with an occurrence rate of 11.7%,besides residential quarters,enterprises and institutions.The main links of pollution were observed in municipal water distribution system(51.7%)and water storage tanks high and low lying(43.3%).The main causes of pollution accidents were the leakage and breakage facilities and mislink between the water pipes and sewage pipes, which resulted in formation of negative pressure.Siphonage and sewage flowing backward,in addition the poor sanitary protection facilities polluted by sewage and rubbish. It was the top priorities to establish special legal system,to enhence the preventive sanitary inspection