Profiling dynamics of the Southeast Asia's largest lake, Tonle Sap Lake.

Lakes, as vital components of the Earth's ecosystem with crucial roles in global biogeochemical cycles, are experiencing pervasive and irreparable worldwide losses due to natural factors and intensive anthropogenic interferences. In this study, we investigated the long-term dynamic patterns of the Tonle Sap Lake, the largest freshwater lake in the Mekong River Basin, using a series of hydrological data and remote sensing images between 2000 and 2020. Our findings revealed a significant decline in the annual average water level of the lake by approximately 2.1 m over 20 years, accompanied by an annual average reduction in surface area of about 1400 km2. The Tonle Sap Lake exhibited episodic declines in water level and surface area, characterized by the absence of flooding during the flood season and increasing aridity during the dry season. Furthermore, the shoreline of the lake has significantly advanced towards the lake in the northwestern and southern regions during the dry season, primarily due to sedimentation-induced shallowing of the lake edge depth and decreased water levels. In contrast, lake shorelines in the eastern region remained relatively stable due to the constructed embankments for the protection of the cultivated farmland. While the seasonal fluctuations of the Tonle Sap Lake are regulated by regional precipitation in the Mekong River Basin, the prolonged shrinking of the lake can be mainly ascribed to intensive anthropogenic activities. The interception of dams along the upper Mekong River has resulted in a decrease in the inflow to Tonle Sap Lake, exacerbating its shrinkage. Moreover, there are minor impacts from agricultural land expansion and irrigation on the lake. This study highlights the driving forces behind the evolution of Tonle Sap Lake, providing valuable information for lake managers to develop strategies aimed at conserving and restoring the ecological integrity of the Tonle Sap Lake.

Three-dimensional reconstruction to improve the success rate in the first attempt of radiofrequency ablation for small hepatocellular carcinoma / 中华肝胆外科杂志

Objective To evaluate the use of three-dimensional reconstruction (3D) to improve the success rate in the first attempt of radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC).Methods A retrospective study was conducted on 109 patients with small HCC (with single nodule from 3 to 5 cm in diameter) treated with radiofrequency ablation between June 2010 and June 2013.A safe ablation margin was evaluated before and after radiofrequency ablation.The patients were divided into two groups: the 3D-RFA group (49 patients were evaluated by three-dimensional reconstruction before RFA treatment) and the 2D-RFA group (60 patients were not evaluated by three-dimensional reconstruction before RFA treatment).The success rate of the first attempt of radiofrequency ablation, recurrence free survival, overall survival and complications were compared between the two groups.Results The success rate of first ablation reached 95.9％ (47/49) in the 3D-RFA group which was significantly higher than the 48.3％ (29/60) in the 2D-RFA group (P ＜ 0.05).The local tumor progression rate was 8.1％ in the 3D-RFA group versus 23.3％ in the 2D-RFA group (P ＜0.05).The 1-, 2-, 3-year recurrence free survival rates were 85.4％, 63.9％, and 49.8％ respectively in the 3D-RFA group and 72.4％, 43％, and 34.4％ respectively in the 2D-RFA group (P ＜ 0.05).The 1-, 2-, 3-year overall survival rates were 91.4％,78.4％, and 60.9％ respectively in the 3D-RFA group and 83.3％, 58.7％, and 40.9％ respectively in the 2D-RFA group (P ＜0.05).Complications occurred significantly less in the 3D-RFA group (4％, 2/49) than the 2D-RFA group (13.3％, 8/60;P ＜ 0.05).Conclusion Three-dimensional reconstruction improved the success rate of the first attempt of radiofrequency ablation and the prognosis of patients, and with less complications for small hepatocellular carcinoma.

Effect of GPR49 gene on proliferation and invasive ability of hepatoma cells / 器官移植

Objective To discuss the effect of G-protein-coupled receptor 49 (GPR49)gene on proliferation and invasive ability of hepatoma cell line Huh7 and its molecular biological mechanism.Methods According to the different transfected small interfering RNA(si-RNA),Huh7 cells were divided into the GPR49-siRNA(si-GPR49)group and the NC-siRNA (si-NC)group.Untransfected Huh7 cells were set as the control group. Messenger RNA (mRNA )and protein expression of GPR49, cyclin D1 and matrix metalloproteinase 9 (MMP9)in the cells of the three groups were respectively detected by reverse transcription-polymerase chain reaction (RT-PCR)and Western blot method.The proliferation and invasive ability of the cells of each group were respectively detected by MTT method and Transwell method.Results The relative expression of GPR49 mRNA of the si-GPR49 group was (23.8 ±3.1)% of the control group (P <0.05). Compared with the control group,the protein expression of GPR49,cyclin D1 and MMP9 of the si-GPR49 group decreased significantly (all in P <0.05).The proliferation experiment results by MTT indicated that the optical density(OD)of the cells of the si-GPR49 group at 72 h was (0.53 ±0.12),which was significantly lower than that of the control group (1.35 ±0.28).The difference had statistical significance (P <0.05). The average invaded cell counts of the si-GPR49 group were (13.6 ±2.5),which was significantly lower than (65.3 ±6.1 )of the control group.The difference had statistical significance (P <0.05 ).Conclusions GPR49-siRNA may inhibit the gene expression of GPR49 in Huh7 cells.Its mechanism may be that the proliferation of Huh7 cells is inhibited by reducing the level of cyclin D1;the migration and invasive ability of Huh7 cells is inhibited by affecting the expression level of MMP9.

Comparison of long-term outcomes between Billroth-I and Roux-en-Y reconstruction after distal gastrectomy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare the long-term outcomes of Billroth-I and Roux-en-Y reconstruction after distal gastrectomy.</p><p><b>METHODS</b>Clinical data of 151 patients with gastric cancer undergoing distal gastrectomy in the Affiliated Oncologic Hospital of Guangzhou Medical University between June 2000 and June 2010 were analyzed retrospectively. Reconstruction was performed with Billroth-I in 87 patients (B-I group) and Roux-en-Y in 64 (R-Y group). All the patients were followed up for at least 3 years. Three years after operation, clinical symptoms, endoscopic findings, nutritional status, gallstone formation, and late gastrointestinal complications were compared between the two groups.</p><p><b>RESULTS</b>Three years after operation, gastroesophageal reflux symptoms were found in 10 patients (11.5%) in B-I group and in 3 (4.7%) in R-Y group, and dumping syndrome was diagnosed in 8 patients (9.2%) in B-I group and in 3 (4.7%) in R-Y group, but the differences between the two groups were not statistically significant (both P>0.05). Endoscopic examination showed that the amount of residue in the gastric stump, remnant gastritis-reflux esophagitis, and bile reflux in R-Y group were better as compared to B-I group (all P<0.05). Body weight, serum albumin level, and total cholesterol level were similar in the two groups (all P>0.05). The incidences of gallstone formation and late gastrointestinal complications did not differ between B-I group and R-Y group (13.2% vs. 15.8%, and 8.0% vs. 4.7% respectively, both P>0.05).</p><p><b>CONCLUSION</b>As compared with Billroth-I, Roux-en-Y is associated with better long-term outcomes in terms of less remnant gastritis-reflux esophagitis and less bile reflux into the gastric remnant.</p>

Predicting value of serum CEA and CA19-9 in neoadjuvant chemotherapy for advanced gastric carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the predictive value of CEA and CA19-9 in tumor progression, prognosis and neoadjuvant chemotherapy of advanced gastric cancer.</p><p><b>METHODS</b>Clinical data of 322 patients with advanced gastric cancer(54 cases undergoing neoadjuvant chemotherapy) from the Affiliated Oncologic Hospital of Guangzhou Medical College were reviewed. Serum CEA and CA19-9 levels were detected by electrochemiluminescence immunoassay, while the expression of CEA and CA19-9 protein in 54 pairs of tumor tissues and matched biopsies neoadjuvant chemotherapy were determined by immunohistochemistry.</p><p><b>RESULTS</b>The expression levels of serum CEA and CA19-9 were closely related to tumor invasion, lymph node metastasis and TNM stage(all P<0.05). The 5-year cumulative survival rates of patients with serum CEA-positive and CA19-9-positive were 17.0% and 11.9%, compared with 34.6% and 34.8% of the patients with serum CEA-negative and CA19-9-negative respectively (both P<0.05). Neoadjuvant chemotherapy could down-regulate CEA and CA19-9 expressions in tumor tissues(P<0.05), while there was no significantly difference in serum level(P>0.05).</p><p><b>CONCLUSIONS</b>The expressions of serum CEA and CA19-9 are closely associated with tumor progression and prognosis in advanced gastric cancer. However, further study should be done to evaluate their value in selecting patients to receive neoadjuvant chemotherapy.</p>

Preoperative intra-arterial chemotherapy for progressive lower rectal cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the therapeutic effect of preoperative regional intra-arterial chemotherapy (PRAC) on progressive lower rectal cancer.</p><p><b>METHODS</b>Forty-five patients with progressive lower rectal cancer were divided into groups A (23 cases) and B (22 cases) for treatment with PRAC 1 to 2 weeks prior to surgical tumor resection or with surgical resection only, respectively.</p><p><b>RESULTS</b>PRAC caused obvious tissue degeneration and necrosis of rectal cancer with a total effective rate of 95.65%. The rates of radical resection in groups A and B were 91.3% and 72.27%, respectively. The 1-year postoperative survival rates of the two groups were 95.65% and 86.36%, with 3-year survival of 89.96% and 68.18%, and 3-year postoperative recurrence rates of 8.69% and 27.27%, respectively. The anal preservation rates of the two groups were 78.26% and 59.09%.</p><p><b>CONCLUSION</b>PRAC can increase radical resection rates, promote the postoperative survival and anal preservation rate, and lower the recurrence rate in patients with lower rectal cancer.</p>