A graph-theory-based method for processing of currency metabolites in metabolic networks / 生物工程学报

Graph-theory-based pathway analysis is a commonly used method for pathway searching in genome-scale metabolic networks. However, such searching often results in many pathways biologically infeasible due to the presence of currency metabolites (e.g. H+, H2O, CO2, ATP etc.). Several methods have been proposed to address the problem but up to now there is no well-recognized methods for processing the currency metabolites. In this study, we proposed a new method based on the function of currency metabolites for transferring of functional groups such as phosphate. We processed most currency metabolites as pairs rather than individual metabolites, and ranked the pairs based on their importance in transferring functional groups, in order to make sure at least one main metabolite link exists for any reaction. The whole process can be done automatically by programming. Comparison with existing approaches indicates that more biologically infeasible pathways were removed by our method and the calculated pathways were more reliable, which may facilitate the graph-theory-based pathway design and visualization.

Myocardial Blood Flow Quantified by Low-Dose Dynamic CT Myocardial Perfusion Imaging Is Associated with Peak Troponin Level and Impaired Left Ventricle Function in Patients with ST-Elevated Myocardial Infarction

OBJECTIVE: To investigate the association of myocardial blood flow (MBF) quantified by dynamic computed tomography (CT) myocardial perfusion imaging (MPI) with troponin level and left ventricle (LV) function in patients with ST-segment elevated myocardial infarction (STEMI). MATERIALS AND METHODS: Thirty-five STEMI patients who successfully had undergone reperfusion treatment within 1 week of their infarction were consecutively enrolled. All patients were referred for dynamic CT-MPI. Serial high-sensitivity troponin T (hs-TnT) levels and left ventricular ejection fraction (LVEF) measured by echocardiography were recorded. Twenty-six patients with 427 segments were included for analysis. Various quantitative parameters derived from dynamic CT-MPI were analyzed to determine if there was a correlation between hs-TnT levels and LVEF on admission and again at the 6-month mark. RESULTS: The mean radiation dose for dynamic CT-MPI was 3.2 ± 1.1 mSv. Infarcted territories had significantly lower MBF (30.5 ± 7.4 mL/min/100 mL versus 73.4 ± 8.1 mL/min/100 mL, p < 0.001) and myocardial blood volume (MBV) (2.8 ± 0.9 mL/100 mL versus 4.2 ± 1.1 mL/100 mL, p = 0.044) compared with those of reference territories. MBF showed the best correlation with the level of peak hs-TnT (r = −0.682, p < 0.001), and MBV showed a moderate correlation with the level of peak hs-TnT (r = −0.437, p = 0.026); however, the other parameters did not show any significant correlation with hs-TnT levels. As for the association with LV function, only MBF was significantly correlated with LVEF at the time of admission (r = 0.469, p = 0.016) and at 6 months (r = 0.585, p = 0.001). CONCLUSION: MBF quantified by dynamic CT-MPI is significantly inversely correlated with the level of peak hs-TnT. In addition, patients with lower MBF tended to have impaired LV function at the time of their admission and at 6 months.

Clinical application of adjuvant treatment after operation in patients with stage IIIa non-small cell lung cancer / 中国肺癌杂志

<p><b>BACKGROUND AND OBJECTIVE</b>The efficacy of complete resection of the cancer for patients with stage IIIa non-small cell lung cancer (NSCLC) is limited. Synthetic therapy is taken the lead in advocating at present. However, the value of post-operative radiotherapy is not still clear. The aim of this study is to evaluate the survival time and side effects of postoperative chemotherapy or chemoradiotherapy in the treatment of stage IIIa NSCLC.</p><p><b>METHODS</b>Between December 2003 and June 2007, 52 cases that have completed followed-up data with stage IIIa of NSCLC received in the First Affiliated Hospital of Dahan Medical University. Twenty-three patients received postoperative chemoradiotherapy (group A) and 29 patients received postoperative chemotherapy combined with radiotherapy (group B). Group A adopted platinum-based combination chemotherapy for 4-6 cycles. The chemotherapeutics included gemcitabine, vinorelbine and docetaxel. Group B used chemotherapy for 2-4 cycles and then received 3-dimensional conformal radiotherapy (3D-CRT). The prescribe dose of target volume was 50 Gy. The chemotherapy was same as for group A and needed 4 cycles in all. The impact of postoperative adjuvant treatment on survival and toxicity was observed in patients with stage IIIa NSCLC and the reason of disease progression was analyzed.</p><p><b>RESULTS</b>The median survival was 32.5 months in group A and 31.9 months in group B (P = 0.371). Progression-free survival extended about 6 months (P = 0.044). The survival rate was 87% at 1 year, 0.1% at 2 year, 33% at 3 year for group A compared with 93%, 69%, 45% for group B. The major side effects were hematological and gastrointestinal toxicities, including nausea, vomiting and neutropenia. There was no significant difference in these toxicities between the two groups (P > 0.05). Radioactive esophageal infection occurred in 17.2% of the patients. Acute and late radioactive lung infection occurred in 13.8% and 27.6% of the patients. All these toxicities were below degree 2. Distant metastases were the main reason of disease progression. There was no significant difference in the rates of local recurrence and metastases between the two groups (P > 0.05).</p><p><b>CONCLUSION</b>Combined modality therapy should be the main therapy of stage IIIa NSCLC. The addition of radiotherapy can effectively prolong progression-free survival and don't highly increase the toxicities.</p>

Expression of MMP-2, c-erbB-2 and clinical significance in non-small cell lung cancer / 肿瘤研究与临床

Objective To investigate the expression of MMP-2 and c-erbB-2 and evaluate the correlation of clinical pathological parameters in non-small cell lung cancer. Methods Forty-five paraffin-embedded specimens of radical postoperative non-small cell lung cancer was detective for MMP-2 and c-erbB-2 using immunohistochemical method. Results The positive rates of MMP-2 and c-erbB-2 are 57.8 %, 75.6 %, there is a significance between the expression of MMP-2 and lymph node metastases(P =0.006), the expression of c-erbB-2 is related to clinical stage and lymph node metastases (P =0.015, P =0.032), The expression of MMP-2 and c-erbB-2 are related to 5-year survival rate (P =0.002, P =0.003). Conclusion The expression of MMP-2 and c-erbB-2 is significantly related to some clinical parameters and 5-year survival rate.