Relationship between endothelial damage and p120-catenin in paraquat intoxication and the protective effect of mangiferin / 中华危重病急救医学

Objective To investigate the relationship between endothelial damage and p120-catenin (p120-ctn) in a model of paraquat intoxication,and the modulatory effect of mangiferin on p120-ctn.Methods Human umbilical vein endothelial cells (HUVECs) were cultured in two compartment spreading apparatus in vitro.The endothelial cells were divided into three groups:control group (cultured in DMEM with 10％ fetal bovine serum),paraquat group (paraquat was added to the medium with final concentration of 0.05 μmol/L) and mangiferin group (cultured in medium with addition of paraquat for 30 minutes,then mangiferin was added in a final concentration of 20 μmol/L).The cellular permeability at 6,12,24,48,72 hours after culture in the three groups was measured.The expressions of p120-ctn 1A,p120-ctn 3A mRNA and p120-ctn protein were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot analysis.The distribution of p120-ctn protein was observed by immunofluorescence.Results Compared with control group,cellular permeability in paraquat and mangiferin groups were increased with prolongation of time,and peaked at 72 hours [(29.86 ± 3.98)％,(24.39 ± 2.79)％ vs.(11.71 ± 1.67)％,both P＜0.05].The cellular permeability was significantly lower in mangiferin group than that in paraquat group at different time points (all P＜0.05).At 6 hours after intoxication,the expressions of p120-ctn 1A,p 120-ctn 3A mRNA (gray value) and p 120-ctn protein (gray value) were significantly lower in paraquat group than those in control group (p120-ctn 1A mRNA:0.150 ± 0.024 vs.0.433 ± 0.024,p120-ctn 3A mRNA:0.316 ± 0.043 vs.0.701 ±0.020,p120-ctn protein:0.485 ±0.031 vs.0.763 ±0.038,all P＜0.01).The expressions of p120-ctn 1A,p120-ctn 3A mRNA and p120-ctn protein were significantly higher in mangiferin group than those in paraquat group from 6 hours on (p120-ctn 1A mRNA:0.281 ± 0.021 vs.0.150 ± 0.024,p120-ctn 3A mRNA:0.602 ± 0.042 vs.0.316 ± 0.043,p120-ctn protein:0.675 ± 0.031 vs.0.485 ± 0.031,all P＜0.01),and they were gradually increased with prolongation of time,and peaked at 72 hours (p120-ctn 1A mRNA:1.376 ±0.128 vs.0.150 ± 0.024,p120-ctn 3A mRNA:1.251 ± 0.059 vs.0.316 ± 0.043,p120-ctn protein:0.844 ± 0.050 vs.0.485 ± 0.031,all P＜ 0.01).Under upright fluorescence microscope,p120-ctn was mainly distributed in the cell membrane in control group,with a slight expression in cytoplasm,and no expression in the nuclei.With prolongation of time,p120-ctn expression in the cell membrane was gradually decreased in paraquat group,while it was increased in the cytoplasm and nuclei,with blurring of cell membrane and widening of cellular gap.p120-ctn expression was improved on the cell membrane in mangiferin group at corresponding time points,with decreased in expression in nuclei and cytoplasm.Conclusion The p120-ctn protein plays an important role in the enhancement of endothelial permeability in paraquat intoxication,and mangiferin may attenuate endothelial injury in paraquat intoxication possibly through modulation of p 120-ctn protein.

Comparison between Kidney and Hemoperfusion for Paraquat Elimination

The mortality rate of acute paraquat (PQ) poisoning depends on the PQ concentration in the blood. It has been shown that the kidneys eliminate PQ effectively. However, early renal function deterioration is frequently observed in acute PQ intoxication. This study is designed to compare the efficacy of PQ elimination with hemoperfusion (HP) and kidneys, taking into account the functional deterioration of the kidneys. The amount of renal and HP excretion of PQ were measured during the procedure of HP in patients with acute PQ intoxication. The PQ clearance and the actual amount of PQ elimination by the HP cartridge during the HP procedure were 111+/-11 mL/min (range; 13.2-162.2 mL/min) and 251.4+/-506.3 mg (range; 4.6- 1,655.7) each. While, the renal clearance and actual amount of renal elimination of PQ was 79.8+/-56.0 mL/min (range; 9.7-177.0) and 75.4+/-73.6 mg (range; 4.9- 245.8). As the creatinine clearance decreased, the PQ elimination by HP was as effective as or more effective than the renal elimination. In conclusion, early HP must be provided for life saving treatment in patients with acute PQ intoxication.

Management of oral mucositis owing to chemical burn by intoxication of agricultural chemicals(gramoxon): report of cases

Chemical burns onto oral mucosa which are infrequent, may result from contact with a wide variety of chemical agents. The degree of injury depends on the chemical, its concentration, duration of contact, and the natural penetrability and resistance of the tissues involved. Chemicals do not usually "burn" in that they do not cause destruction by hyperthermic activity. Rather, they damage tissue by causing coagulation of protein by one of several processes, reduction, oxidation, desiccation, corrosion, or vesication. Paraquat(Gramoxon) is the most frequently agricultural chemicals that induce the severe toxic reactions onto the organs of human body in Korea. The toxic reaction are composed of pulmonary edema and fibrosis, formation of hyaline membrane, inflammatory reaction and bleeding tendency, owing to the cell damage by the production of superoxide radicals. The contents of essential treatment in paraquat intoxication are commonly airway and breathing maintenance, gastric lavage, much hydration and diuresis, hemoperfusion and medications for the removal of the chemicals and the prevention of various complications. The sedative oral dressings, such as, orabase ointment application, warm saline gargling, lidocaine viscous gargling and oral gargling by the mixed solutions(tetracycline, prednisolone and 10% dextrose water) are important for the improvement of chemical oral mucositis and the comfortable feeding of diet. The authors managed properly two cases of oral chemical mucositis that were occurred by the incorrect use of agricultural chemicals(paraquat) and report the cases with the review of literatures about care of the chemical intoxication and oral mucositis.

Antioxidant Therapy of the Paraquat Intoxication

BACKGROUND: Paraquat causes severe tissue toxicity when ingested, but has no effective treatment modality. We have shown that high dose vitamin C has effective antioxidant activities against the paraquat intoxication in a previous animal experiment. This study was designed to evaluate the effect of antioxidant therapy with high dose vitamin C and vitamin E in human cases of paraquat intoxication. METHODS: From August 1999 to August 2001, 19 paraquat intoxication patients who visited the emergency department of the Seoul National University Hospital and the Kyounghee University Hospital were enrolled to this study. They were devided into two groups, a control group(9 patients) and a study group(10 patients). The control group received only conservative managements including gastro-intestinal decontaminati-on. The study group received conservative managements plus the antioxidant therapy which was composed of vitamin C 24 gm/day intravenously and 20 gm/day orally, and vitamin E 1.6 gm/day orally. RESULTS: In the study group, 5 of 10 patients(50%) survived, but all patients of the control group died(p=0.003). There were no significant differences in age, sex, and usage of gastric lavage and activated charcoal between the two groups. Difference in ingested amount of paraquat between the two groups could not be analyzed due to the inexact and subjective measuring methods based on patients'histories. CONCLUSION: Antioxidant therapy with high dose vitamin C and vitamin E is effective in improving survival rate in paraquat intoxicated patients.

In vitro studies on the treatment of paraquat intoxication with activated carbon / 日本農村医学会雑誌

Concerning the intoxication by agricultural chemicals, adsorption removal of paraquat by activated carbons for initial treatment of paraquat intoxication in vitro was investigated. The amount of paraquat adsorbed was significantly related to the surface pH of activated carbon. It was not found the significant correlation between amount of paraquat adsorbed and physical properties of ten kinds of activated carbons.<BR>Moreover, the influence of sorbitol addition on the amount of paraquat adsorbed was studid. The amonut of paraquat adsorbed onto activated carbon was unaffected by sorbitol addition.

Studies on oral adsorbents for treatment of paraquat intoxication / 日本農村医学会雑誌

Oral adsorbents used in the primary treatment of paraquat intoxication were studied in saline to evaluate their effectiveness in terms of removal ratio and removal rate.<BR>Forty kinds of materials were tested as paraquat adsorbents.<BR>Although cation exchange resin had the greatest removal ratio for paraquat, a high removal ratio was registered by an activated carbon derived from petroleum pitch. A significant correlation between removal ratio and the degree of crosslinkage in the resin was found.<BR>The degree of paraquat concentration decrease was high when cation exchange resin was used. A significant correlation was found between the kinetic constant, which was calculated from the equation for a first-order reaction, and the degree of crosslinkage in the resin.