Objective: To investigate the pathological changes of human hepatocellular carcinoma (HCC) after continuous passaging in nude mice. Methods: The mice model of HCC SMMU-LTMN were continuously observed for 20 years (1987-2007) . The subcutaneously transplanted carcinoma had been passaged for 228 generations. The pathological data of abdominally transplanted HCC, orthotopically transplanted HCC in nude mice, and orthotopically transplanted HCC in NOD-SCID mice were recorded. The pathological studies were conducted by light microscope, electron microscope, image analysis, chromosomal analysis, and measurement of alpha-fetoprotein (AFP) in peripheral blood. Results: (1) The local invasion and metastasis of of tumors were present in all the above 4 models for a long time. The local invasion rate and the pulmonary metastasis rate of subcutaneously transplanted tumors were 59.70% (40/67) and 37.10% (23/62), respectively. The pulmonary metastasis rate of abdominally transplanted tumors was 59.02%(36/61). The intra-hepatic and pulmonary metastasis rate of the othotopically transplanted tumors were 18.18%(4/22) and 31.82% (7/22), respectively. The pulmonary metastasis rate of HCC in NOD-SCID mice was 53.85%. (2) The tissue structure and the differentiation of the 10th generation tumor cells was similar to those of primary HCC, with grade 2 differentiation and coarse trabecular pattern as the main characteristics. From the 11th generation to the 228th generation, the main characteristics of tumor cells were grade 3 differentiation and lump pattern. Electron microscope also showed worse differentiation. (3)The AFP level was 92 500 ?g/L in cells before the 32th generation; it decreased to 6 729?g/L from the 33th-130th generation cells; and the level of the 220th generation was 1 000-5 000 ?g/L.(4)The DNA contents had a wide distribution (from 2c to 6c) in abdominally transplanted tumors and the pulmonary metastatic tumors; the mean DNA index in the former tumors (2.60?0.20) was wider than the that in the latter (2.10?0.26) . (5)From the 55th generation to 206th generation, it was found that tumor cells had integrated into the chromosome of the nude mice. Conclusion: The subcutaneously transplanted HCC in nude mice can be stably expressed for 20 years, with no change in the local invasion and metastasis ability of HCC. The differentiation of the tumor cells worsenes and the AFP level is decreased in the blood; some chromosome of tumor cells integrate into the chromosome of nude mice, which may be related to the internal environment of nude mice and the multi-potential differentiation of the tumor cells.

Rhamnolipid biosurfactant is mainly produced by Pseudomonas aeruginosa that is the opportunistic pathogenic strain and not suitable for future industrial development. In order to develop a relatively safe microbial strain for the production of rhamnolipid biosurfactant, we constructed engineered Escherichia coli strains for rhamnolipid production by expressing different copy numbers of rhamnosyltransferase (rhlAB) gene with the constitutive synthetic promoters of different strengths in E. coli ATCC 8739. We further studied the combinatorial regulation of rhlAB gene and rhaBDAC gene cluster for dTDP-1-rhamnose biosynthesis with different synthetic promoters, and obtained the best engineered strain-E. coli TIB-RAB226. Through the optimization of culture temperature, the titer of rhamnolipd reached 124.3 mg/L, 1.17 fold higher than that under the original condition. Fed-batch fermentation further improved the production of rhamnolipid and the titer reached the highest 209.2 mg/L within 12 h. High performance liquid chromatography-mass spectrometry (LC-MS) analysis showed that there are total 5 mono-rhamnolipid congeners with different nuclear mass ratio and relative abundance. This study laid foundation for heterologous biosynthesis of rhanomilipd.
Bacterial Proteins ; genetics ; Batch Cell Culture Techniques ; Decanoates ; Escherichia coli ; metabolism ; Fermentation ; Glycolipids ; biosynthesis ; Hexosyltransferases ; genetics ; Industrial Microbiology ; methods ; Multigene Family ; Promoter Regions, Genetic ; Pseudomonas aeruginosa ; Rhamnose ; analogs & derivatives ; biosynthesis ; Surface-Active Agents ; metabolism

Objective To evaluated the safety and clinical efficacy of CT-guided percutaneous radioactive 125I seeds implantation in treatment of spinal metastatic tumors.Methods Totally 20 cases (23 lesions) of spinal metastatic tumors with spinal compression and severe back pain were treated by CT-guided percutaneous 125I seeds implantation.Intractable pain and nerve function before and after therapy were evaluated.And the postoperative cumulative local tumors control rates and cumulative survival rates were calculated.Results The median follow-up period was 14 months (range 7-32months).There was no patient lost follow-up.And no severe complication occurred.Intractable pain significantly relieved one month after therapy.The neural retention rate of 12 patients with nerve function impairment was 85.00％ (17/20) and the neural function recovery rate was 30.00％ (6/20) three months after 125 I seeds'implantation.The local tumors control rates in 3-,6-,and 12-month were 100％,100％ and 90％,respectively.The survival rates in 6-and 12-month was 100％and 78.81％,respectively.Conclusion CT-guided percutaneous radioactive 125I seeds implantation for spinal metastatic tumors is safe and feasible.It can relief pain and improve neural function effectively.

Objective To evaluate the efficacy and safety of biliary stent loaded with 125I seeds in treatment of hilar cholangiocarcinoma with malignant obstructive jaundice.Methods Totally 43 patients with malignant obstructive jaundice caused by cholangiocarcinoma were included.All the patients underwent percutaneous transhepatic puncture of the left and right side branch of the bile duct.In the hilar stenosis,the biliary stent with 125I seeds were implanted,and the biliary drainage tube had been kept in 3 to 5 days after procedures.The drainage tube was removed and the puncture road was closed after the patency of stents were confirmed by cholangiography.The changes of liver function before and after procedures were recorded,and the survival time was observed.Results Five biliary stents loaded with 125I seeds were implanted in type I (n=5),36 in type Ⅱ (n=18),8 in type Ⅲ (n=4) and 25 in type Ⅳ (n=16).The serum total bilirubin and direct bilirubin of patients before procedures were (145.54 ± 65.35) μmol/L and (124.73 ± 35.04) μmol/L,respectively,and (65.91±29.43)μmol/L and (35.50±15.12)μmol/L respectively after procedures.Compared with preoperative,the total bilirubin,direct bilirubin,alanine aminotransferase,aspartate aminotransferase,alkaline phosphatase,C-reactive protein and gamma glutamic transaminase decreased significantly (all P＜0.05).The lactate dehydrogenase had no significant difference before and after operation (P=1.050).The median survival time was 13 months (3.0 to 22.5 months).The serious complications such as biliary puncture,pancreatitis,severe biliary tract infection or biliary bleeding were not occurred.Conclusion Biliary stent loaded with 125 I seeds is an effective therapy to alleviate symptoms of jaundice and prolong the survival time of patients with malignant obstructive jaundice caused by hilar cholangiocarcinoma.

Objective To investigate the clinical value of coplanar template-assisted CT guided radioactive seeds implantation in the treatment of pancreatic carcinoma. Methods A total of 22 advanced pancreatic carcinoma patients underwent CT guided radioactive seeds implantation were retrospectively analyzed.Ten patients were treated with coplanar template-assisted with an average age of(65±10)years(48 to 77 years).Tweleve patients were treated without coplanar template assist with an average age of(68±13) years (47 to 84 years). The preoperative planning designs and postoperative dosimetry verifications were performed for all patients.The dose related parameters including D90,MPD,V100,V150and V200were compared between pre and post operation by t test. The operating time were also evaluated between the two groups. Results Overall the 22 patients were treated successfully without serious surgery-related complications. An average of 26 seeds were implanted in the coplanar template assisted implantation group,and 23 seeds were implanted in the non template-assisted implantation group. Preoperative V100in coplanar template group and non template group were(94.45 ± 1.32)% and(93.27 ± 1.37)% separately. Postoperative V100in both groups were(89.31 ± 2.58)% and(85.25 ± 4.35)% separately. Postoperative D90in both groups were (147.32±7.12)Gy and(149.25±4.86)Gy separately.Postoperative V150in both groups were(57.83±7.74)% and(63.97±7.75)% separately.Preoperative D90in both groups were(152.41±6.78)Gy and(153.30±7.79) Gy separately. Preoperative V150in both groups were(58.61 ± 14.11)% and(62.45 ± 6.49)% separately. Postoperative MPD in both groups were(87.64±10.60)Gy and(87.12±7.66)Gy separately.Postoperative V200in both groups were(34.12±7.67)%,(39.42±7.18)% separately.Preoperative MPD in both groups were (82.12±7.81)Gy and(83.43±4.86)Gy separately.Preoperative V200in both groups were(29.04±10.64)%, (36.11 ± 7.22)% separately. Compared with preoperative plans, the mean value of D90and V100decreased while the mean value of MPD and V200increased in postoperative verifications in both coplanar template assist CT guided radioactive seeds implantation group and non template-assisted group.However,there was no significant difference between pre and post operation except for V100(P<0.05). The operating time of coplanar template assist group and non template-assisted group were(44.3±12.4)min and(60.0±12.8)min respectively. The difference of operating time between two groups were statistically significant (P<0.05). Conclusion Compared with the treatment without template assist, coplanar template-assisted brachytherapy could be more accurate in preoperative plans optimization,and shorten the operation time and improve the patients'tolerance.