As the rapid growth of population and economic development,the types and intensity of water pollution in urban river stream are increasing,which on one hand restrict the sustainable development of the social,economic and environment,on the other hand,damage people health. Since having safety,economy,practicality,systematic and other merits,ecological remedy technology has been the main means for controlling river contamination. In this paper,the recent researches on the ecological restoration technique for the urban stream in China in recent years were reviewed.

Objective To evaluate the clinical value of percutaneous transchepatic biliary internal external drainage (PTBIED) in treatment of malignant biliary obstruction.Methods Forty-three patients with malignant biliary obstruction,including 14 cases with hilary metastasis cancer 8 with carcinoma of gallbladder,8 with hilary biliary cancer,13 with pancreatic cancer were treated with PTBIED.Results The technical success rate was 90%.The serum total bilirubin almost fell to normal level in 40 patients.Four cases (9.3%) died within 1 month, twenty (46.5%) cases died within 6 months,thirteen (30.2%) cases are still alive 12 months later.The complications cases mild hemobilia (8 cases,18.6%),bacteriemia(10 cases,23.3%),retrograde infection(6 included,14.0%).Conclusion PTBIED is an effective and safe therapeutic method for palliation of malignant biliary obstruction.

Irinotecan is an anticancer topoisomerase I inhibitor that acts as a prodrug of the active metabolite, SN-38. Unfortunately, the limited utility of irinotecan is attributed to its pH-dependent stability, short half-life and dose-limiting toxicity. To address this problem, a novel trivalent PEGylated prodrug (PEG-[Irinotecan]₃) has been synthesized and its full-profile pharmacokinetics, antitumor activity and toxicity compared with those of irinotecan. The results show that after intravenous administration to rats, PEG-[Irinotecan]₃ undergoes stepwise loss of irinotecan to form PEG-[Irinotecan]_3‒x (x = 1,2) and PEG-[linker] during which time the released irinotecan undergoes conversion to SN-38. As compared with conventional irinotecan, PEG-[Irinotecan]₃ displays extended release of irinotecan and efficient formation of SN-38 with significantly improved AUC and half-life. In a colorectal cancer-bearing model in nude mice, the tumor concentrations of irinotecan and SN-38 produced by PEG-[Irinotecan]₃ were respectively 86.2 and 2293 times higher at 48 h than produced by irinotecan. In summary, PEG-[Irinotecan]₃ displays superior pharmacokinetic characteristics and antitumor activity with lower toxicity than irinotecan. This supports the view that PEG-[Irinotecan]₃ is a superior anticancer drug to irinotecan and it has entered the phase II trial stage.