The effect of gene therapy on postoperative recurrence of small hepatocellular carcinoma (less than 5cm).

To observe the curative effect of surgery combined with gene therapy on small hepatocellular carcinoma. Seventy-seven patients with small hepatocellular carcinoma (diameter < 5 cm) underwent surgical resection. The tumor located at the edge of the liver was treated by local excision or irregular hepatectomy. The tumor in the center of the liver was resected by hepatic lobectomy in order to ensure at least a 2-cm safety margin. Fifty-four patients underwent gene therapy (gene group) one or two times before operation, whereas 23 patients underwent surgery alone (control group) selected by themselves. The injectable gene was made of ADV-TK (adenovirus containing thymidine kinase suicide gene, with a concentration of 5 × 1012/ml). The prognosis of patients was analyzed by imaging twice a year. In the gene group, the 1-, 3-, and 5-year survival rates were 91.4, 63.6, and 52.1%. In the control group, the survival rates were 84.3, 54.4, and 32.6%, respectively. There was a significant difference in the overall survival rates between two groups. Factors associated with overall survival in univariate analysis included bilirubin, prothrombin activity, cirrhosis, and gene therapy (P < 0.05). In the multivariate analysis, it included cirrhosis, gene therapy, and bilirubin. The gene therapy hepatocellular carcinoma patients with a diameter < 5 cm could significantly reduce recurrence after operation. It was worthy of being popularized.

[Effects of highway on the vegetation species composition along a distance gradient from road edge in southeastern margin of Tengeer Desert].

Aimed to examine the effects of highway on the vegetation species composition in arid desert area, forty-eight transects perpendicular to the provincial highway 201 from Shapotou to Jing-tai in the southeastern margin of Tengger Desert were installed, with the vegetation species distribution along a distance gradient from the road edge investigated. The results showed that with increasing distance from the road edge, the species number, coverage, biomass, and alpha-diversity of herbaceous plants declined, but had no significant differences with the control beyond 5 m. Within 0-6 m to the road edge, the herbaceous plant height was greater than that of the control, but their density had less change. Within 0-2 m to the road edge, the species turnover rate of herbaceous plants was lower; at 2-5m, this rate was the highest; while beyond 10 m, the species composition of herbaceous plants was similar to that of the control. The herbaceous plant community at the road edge was dominated by gramineous plants, with the disturbance-tolerant species Pennisetum centrasiaticum, Chloris virgata, and Agropyron cristatum accounting for 68.6% of the total. C. virgata beyond 1 m to the road edge had a rapid decrease in its individual number and presence frequency, P. centrasiaticum and A. cristatum beyond 2 m also showed a similar trend, while the composite plants Artemisia capillaris and A. frigida beyond 2 m from the road edge had a rapid increase in its individual number, accounting for 70% of the herbaceous plants. At the road edge, the coverage and density of shrubs were significantly lower than those of the control, but the species composition had no significant difference.

Distribution, biomass, and dynamics of roots in a revegetated stand of Caragana korshinskii in the Tengger Desert, northwestern China.

A field experiment was conducted to investigate root distribution, biomass, and seasonal dynamics in a revegetated stand of Caragana korshinskii Kom. in the Tengger Desert. We used soil profile trenches, soil core sampling, and minirhizotron measurements to measure root dynamics. Results showed that the roots of C. korshinskii were distributed vertically in the uppermost portion of the soil profile, especially the coarse roots, which were concentrated in the upper 0.4 m. The horizontal distribution of the root length and weight of C. korshinskii coarse roots was concentrated within 0.6 and 0.4 m of the trunk, respectively. The lateral distribution of fine roots was more uniform than coarse roots. Total-root and fine-root biomasses were 662.4 +/- 45.8 and 361.1 +/- 10.3 g m(-2), accounting for about two-thirds and one-third of the total plant biomass, respectively. Fine-root turnover is closely affected by soil water, and both of these parameters showed synchronously seasonal trends during the growing season in 2004 and 2005. The interaction between fine-root turnover and soil water resulted in the fine-root length densities and soil water content in the 0- to 1.0-m soil layer having similar trends, but the soil water peaks occurred before those of the fine-root length densities.

Establishment of hepatocellular carcinoma multidrug resistant monoclone cell line HepG2/mdr1.

BACKGROUND: The multidrug resistance (MDR) associated with the expression of the mdr1 gene and its product P-glycoprotein is a major factor in the prognosis of hepatocellular carcinoma cell (HCC) patients treated with chemotherapy. Our study was to establish a stable HCC MDR cell line where a de novo acquisition of multidrug resistance specifically related to overexpression of a transgenic mdr1. METHODS: The 4.5-kb mdr1 cDNA obtained from the plasmid pHaMDR1-1 was cloned into the PCI-neo mammalian expression vector, later was transferred by liposome to human hepatocarcinoma cell line HepG2. Then the transfected HepG2 cells resisting G418 were clustered and cultured and the specific fragment of mdr1 cDNA, mRNA and the P-glycoprotein (Pgp) in these HepG2 cells were detected by PCR, RT-PCR and flow cytometry, respectively. The accumulation of the daunorubicin was determinated by flow cytometry simultaneously. The nude mice model of grafting tumour was established by injecting subcutaneously HepG2/mdr1 cells in the right axilla. When the tumour diameter reached 5 mm, adriamycin was injected into peritoneal cavity. The size and growth inhibition of tumour were evaluated. RESULTS: The mdr1 expression vector was constructed successfully and the MDR HCC line HepG2/mdr1 developed. The PCR analysis showed that the specific fragment of mdr1 cDNA in HepG2/mdr1 cells, but not in the control group HepG2 cells. Furthermore, the content of the specific fragment of mdr1 mRNA and Pgp expression in HepG2/mdr1 cells were (59.7 +/- 7.9)% and (12.28 +/- 2.09)%, respectively, compared with (16.9 +/- 3.2)% and (3.07 +/- 1.06)% in HepG2 cells. In the nude mice HCC model, the tumour genes of both groups were identified. After ADM therapy, the mean size of HepG2 cell tumours was significantly smaller than HepG2/mdr1 cell tumours. CONCLUSION: The approach using the transfer of mdr1 cDNA may be applicable to the development of MDR hepatocarcinoma cell line, whose MDR mechanism is known. This would provide the experimental basis of MDR research.