Improving calibration of two key parameters in Hydrologic Engineering Center hydrologic modelling system, and analysing the influence of initial loss on flood peak flows.

Parameter calibration is a key and difficult issue for a hydrological model. Taking the Jinjiang Xixi watershed of south-east China as the study area, we proposed methods to improve the calibration of two very sensitive parameters, Muskingum K and initial loss, in the Hydrologic Engineering Center hydrologic modelling system (HEC-HMS) model. Twenty-three rainstorm flood events occurring from 1972 to 1977 were used to calibrate the model using a trial-and-error approach, and a relationship between initial loss and initial discharge for these flood events was established; seven rainstorm events occurring from 1978 to 1979 were used to validate the two parameters. The influence of initial loss change on different return-period floods was evaluated. A fixed Muskingum K value, which was calibrated by assuming a flow wave velocity at 3 m/s, could be used to simulate a flood hydrograph, and the empirical power-function relationship between initial loss and initial discharge made the model more applicable for flood forecasting. The influence of initial loss on peak floods was significant but not identical for different flood levels, and the change rate of peak floods caused by the same initial loss change was more remarkable when the return period increased.

Relationship between expression of Smac and Survivin and apoptosis of primary hepatocellular carcinoma.

BACKGROUND: The second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI (Smac/DIABLO) was recently identified as a protein that is released from mitochondria in response to apoptotic stimuli and promotes apoptosis by antagonizing inhibitor of apoptosis proteins. Furthermore, Smac/DIABLO plays an important regulatory role in the sensitization of cancer cells to both immune- and drug-induced apoptosis. However, little is known about the clinical significance of Smac/DIABLO in various cancers including hepatocellular carcinoma (HCC). This study was undertaken to investigate the expression of Smac and Survivin and their relationship with the apoptosis in primary HCC. METHODS: The expression of Smac and Survivin proteins was evaluated by immunohistochemistry. The mRNA expression of Smac and Survivin was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) in HCC tissues of 50 patients, para-carcinoma tissues of 20 patients, and normal liver tissues of 15 patients. RESULTS: Smac mRNA was detected by RT-PCR in HCC tissues of 21 (42.0%) of the 50 patients, para-carcinoma tissues of 19 (95.0%) of the 20 patients, and normal liver tissues of 15 (100%) of the 15 patients. Survivin mRNA was found in HCC tissues of 46 of the 50 patients, para-carcinoma tissues of 2 of the 20 patients, and normal liver tissues of 0 of 15 patients. Immunohistochemistry revealed Smac protein in HCC tissues of 20 patients (40.0%), in para-carcinoma tissues of 18 patients (90.0%), and normal liver tissues of 15 patients (100.0%). The expression of Smac was significantly different in HCC tissues and non-HCC tissues. Survivin protein was found in HCC tissues in 45 patients, para-carcinoma tissues in 2 patients, and normal liver tissues in none of the patients. The expression of Survivin was significantly different in HCC tissues and non-HCC tissues. CONCLUSION: Smac inhibits apoptosis of HCC cells by suppression of Survivin, and the two genes probably form an important link in the signal pathway of HCC cells.

Effect of L-arginine on calcium in hepatic mitochondrion in rats with obstructive jaundice.

BACKGROUND: There is much debate over the regulation of mitochondrial calcium overload and reducing the impairment of energy metabolism in hepatic cells. It has not been reported whether L-arginine (L-Arg) can affect hepatic mitochondrial calcium overload. This study was undertaken to investigate the protective effect of L-Arg on Ca2+ handling of hepatic mitochondrion in rats with obstructive jaundice and to clarify its possible mechanism. METHODS: Seventy-two male SD rats were randomly divided into 3 groups: sham operation+normal saline group (SO group), common bile duct ligation+normal saline group (BDL group), and common bile duct ligation+ L-Arg group (L-Arg group). The levels of malondialdehyde (MDA), superoxide dismutase (SOD) and Ca2+ in rat hepatic mitochondrion were examined at the 7th, 14th and 21st day after operation. RESULTS: The Ca2+ and MDA levels of hepatic mitochondrion increased significantly but their SOD content decreased markedly at each time point in the BDL group. Except at the 21st day, the Ca2+ and MDA, contents of hepatic mitochondrion were significantly lower, and SOD concentrations were higher in the L-Arg group than those in the BDL group at the 7th and 14th day (P<0.01). CONCLUSION: L-Arg has a protective effect on mitochondrion in the early and mid stages of obstructive jaundice.

Clinical diagnosis and treatment of abdominal visceral injury complicated by craniocerebral injury.

OBJECTIVE: To improve the cure rate of patients with abdominal visceral injury complicated by craniocerebral injury. METHODS: Clinical data of 176 cases of abdominal visceral injury complicated by craniocerebral injury were retrospectively analyzed. RESULTS: In this series, 44 cases died and the mortality was 25.0. The main cause of death is abdominal visceral injury combined with shock and severe craniocerebral injury. CONCLUSIONS: It is essential to improve the cure rate by accurate diagnosis at early stage. Abdominal paracentesis and CT should be performed promptly and dynamically. Priority should be given to the treatment of life-threatening injuries.

Olmesartan inhibits the expression of monocyte chemoattractant protein-1 and tumor necrosis factor-alpha and improves vascular remodeling after vascular injury in mouse.

OBJECTIVE: To investigate the neointima formation and the expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha) in cuff-induced vascular injury in mouse model, and to examine the effect of angiotensin II type 1 receptor (AT1) blocker, olmesartan, on MCP-1 and TNF-alpha expression and consequently vascular remodeling. METHODS: Vascular injury was induced by polyethylene cuff-placement around the mouse femoral artery. Some mice were treated with AT1 receptor blocker, olmesartan, at the dose of 3 mg.kg(-1).day(-1) with an osmotic minipump. Neointima formation and the proliferation of vascular smooth muscle cells (VSMCs) were measured by morphometric analysis and bromodeoxyuridine (BrdU) incorporation. MCP-1 and TNF-alpha expression was detected by Western blot and immunohistochemical staining. RESULTS: We observed neointima formation 14 days after cuff placement as well as VSMCs proliferation in the media and neointima. Cuff placement also induced MCP-1 and TNF-alpha expression in the media and neointima that the VSMCs specifically existed. Treatment of mice with olmesartan at a dose of 3 mg.kg(-1).day(-1), which did not influence systolic blood pressure, significantly decreased neointima formation and the proliferation of VSMCs. Olmesartan also inhibited MCP-1 and TNF-alpha expression in the injured arteries. CONCLUSIONS: Our results demonstrate that blockade of AT1 receptor inhibits MCP-1 and TNF-alpha expression and thereby improves vascular remodeling.