Potential biosorbent based on sugarcane bagasse modified with tetraethylenepentamine for removal of eosin Y.

Tetraethylenepentamine (TEPA) modified sugarcane bagasse (SB), a novel biosorbent (TEPA-MSB), was proved to be an effective adsorbent for anionic dyes due to the introduced functional amino groups. FTIR, TG and DSC analysis were employed to characterize the sorbent. The effects of pH, temperature, contact time and initial concentration of dye on the adsorption of eosin Y were investigated. The experimental data fit very well to the Langmuir model, giving a maximum sorption capacity of 399.04 mg/g at 25 °C. And the kinetic data were well described by the pseudo-second-order kinetic model. pH 6 was the optimal pH for eosin Y adsorption, and the maximum adsorption capacity of TEPA-MSB calculated by Langmuir model was 18 times higher than that of SB.

[Effects of cardiopulmonary bypass on plasma pentraxin-3 level and the balance of Th1/Th2 function in children with congenital heart malformations].

OBJECTIVE: To investigate the effects of cardiopulmonary bypass (CPB) on plasma pentraxin-3 (PTX3) level and balance of Th1/Th2 function in children with congenital heart malformations. METHODS: 16 children with congenital heart malformations, 9 male and 7 female, aged 3 - 52 months, weighing 3.4 - 14.5 kilograms, classified as II or III ASA grades, underwent operation under CPB. Blood samples were collected after anesthesia induction, 5 min and 30 min since beginning of CPB, and 5 min, 2 h, 4 h, 8 h, and 16 h after weaning from CPB. ELISA was used to examine the plasma concentrations of interferon (INF)-gamma, interleukin (IL)-4, and PTX3. The ratio of INF-gamma/IL-4 was calculated. RESULTS: The INF-gamma level began to increase significantly 5 min since CPB (P < 0.05), peaked 5 min after weaning from CPB (P < 0.01), then gradually decreased, and returned to the level before CPB 16 h after the weaning from CPB (P > 0.05). The IL-4 level began to increase significantly 30 min since CPB (P < 0.01), peaked 2 h since CPB (P < 0.01), however, still not returned to the level before CPB 16 h after the weaning from CPB (P < 0.05). The PTX-3 level was significantly higher 30 min since CPB and 5 min and 2 h after the weaning from CPB (all P < 0.01). The INF-gamma/IL-4 ratio was significantly higher 5 min and 30 min since CPB and 5 min after weaning from CPB (all P > 0.05). CONCLUSION: CPB can leads to elevation of plasma concentration of PTX3 and drift of Th1/Th2 function equilibrium, thus resulting in immunity disequilibrium.

Iron chelator daphnetin against Pneumocystis carinii in vitro.

BACKGROUND: Although there are several drugs and drug combinations for the treatment of Pneumocystis carinii (P. carinii) pneumonia, all drugs have the toxicity as well as low efficacy. Iron chelators have been proposed as a source of new drugs for combating these infections. We hypothesized that iron chelators would suppress the growth of P. carinii by deprivation of the nutritional iron required for growth. In this study, a short-term axenic culture system of P. carinii was established. Daphnetin (7,8-dihydroxycoumarin), a known iron chelator, was demonstrated to exhibit in vitro activity against P. carinii in this system. METHODS: P. carinii organisms were obtained from the lungs of immunosuppressed rats. The culture system consisted of Iscove Dulbecco Eagle's Minimum Essential Medium (IMDM), supplemented with S-adenosyl-L-methionine, N-acetylglucosamine, putrescine, L-cysteine, L-glutamine, 2-mercaptoethanol, and fetal bovine serum, and was maintained at 37 degrees C, in 5% CO(2), 95% O(2), at the optimal pH of 8.0. The culture system was used to assess the effect of daphnetin on the proliferation of P. carinii organisms. The ultrastructures of the treated organisms were observed by transmission electron microscopy. RESULTS: The number of cysts and trophozoites increased 8- to 9-fold and 11- to 12-fold, respectively, after 10 days of culture. Daphnetin was found to suppress the growth of P. carinii in a dose-dependent manner at concentrations between 1 micromol/L and 20 micromol/L. The inhibitory activity was suppressed by the chelation of daphnetin with ferrous sulfate in a 2:1 molar ratio, but it was not suppressed by mixing the culture medium with magnesium sulfate. Reduction of P. carinii numbers after treatment with daphnetin correlated with morphological changes in the organisms, as determined by transmission electron microscopy. CONCLUSIONS: Daphnetin can suppress the growth of P. carinii in vitro. The efficacy of daphnetin in suppressing the the growth of P. carinii in vitro is related to its ability to chelate iron.