[Changes of left ventricular function in cirrhotic patients and their correlation with the model for end-stage liver disease score].

OBJECTIVE: To investigate the changes of left ventricular structure and function in patients with liver cirrhosis and their correlation with the model for end-stage liver disease (MELD) score. METHODS: A total of 89 cirrhotic patients admitted between June, 2012 and June, 2014 and 30 healthy control subjects were enrolled in the study. According to MELD score, the cirrhotic patients were divided into 3 groups with MELD scores ≤9, between 10 and 19, and ≥20. The parameters of the left ventricle in resting state were measured using Doppler echocardiography, including left ventricular end systolic diameter (LVESD), left ventricular end diastolic diameter (LVEDD), interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left atrial diameter (LAD), ejection fraction (LVEF), cardiac output (CO), mitral flow velocity, and E wave deceleration time (DT), and evaluated their relationship with MELD score. RESULTS: Compared with the control subjects, the cirrhotic patients showed significantly increased LVESD, LVEDD, IVST, LAD, CO and DT but reduced VE/VA ratio (P<0.05 or 0.01). The values of LVESD, LVEDD, IVST, LAD and DT increased gradually with MELD scores (P<0.05 or 0.01). VE/VA ratio was higher in patients with MELD score of 10-19 than in those with MELD score ≤9, and decreased significantly in those with MELD score ≥20. Of the cirrhotic patients, 55% were found to have left atrial enlargement and 44% had a VE/VA ratio ≤1; left atrial enlargement and a VE/VA ratio below 1 were more common in patients with a MELD score ≥20 than in those with lower MELD scores. The LAD, LVEDD and DT were positively correlated with MELD scores (r=0.208, 0.319 and 0.197, respectively; P<0.05 or 0.01). CONCLUSIONS: The patients with liver cirrhosis can have cardiac function deficiency manifested mainly by left ventricular diastolic dysfunction in positive correlation with the severity of liver disease.

[Construction of a phage antibody library and screening of anti-epidermal growth factor receptor variant III single chain antibody].

OBJECTIVE: To obtain specific anti-epidermal growth factor receptor variant III (EGFRvIII) single chain antibody (ScFv) by phage antibody library display system. METHODS: The total RNA was extracted from the spleen B cells of BALB/c mice immunized with pep-3-OVA protein, and the first-strand cDNA was synthesized by reverse transcription. Antibody VH and VL gene fragments were amplified and joined to a ScFv gene with the linker. The ScFv gene was ligated into the phagemid vector pCANTAB5E, which was transformed into competent E. coli TG1. The transformed cells were then infected with M13KO7 helper phage to yield the recombinant phage to construct the phage ScFv library. Pep-3-BSA protein was used to screen the phage antibody library and ELISA carried out to characterize the activity of the antibody. RESULTS: The VH and VL gene fragments of the antibody were about 350 bp and 320 bp in length as analyzed by agarose gel electrophoresis. The ScFv gene was 780 bp, consistent with the expected length. The recombinant phagemid with ScFv gene insert was rescued, and an immune phage ScFv library with the content of 5.0x10(6) was constructed. The recombinant ScFv phage had a titer of 3.0x10(4) cfu/ml, and the fourth phage harvest yielded 56 times as much as that of the first one. SDS-PAGE demonstrated a molecular mass of the soluble ScFv of about 28 kD. ELISA results indicated good specificity of the ScFv to bind EGFRvIII. CONCLUSION: An immune phage ScFv library is successfully constructed, and the ScFv antibody fragment is capable of specific binding to EGFRvIII.

Generation of fusion protein EGFRvIII-HBcAg and its anti-tumor effect in vivo.

The epidermal growth factor receptor variant III (EGFRvIII) is the most common variation of EGFR. Because it shows a high frequency in several different types of tumor and has not been detected in normal tissues, it is an ideal target for tumor specific therapy. In this study, we prepared EGFRvIII-HBcAg fusion protein. After immunization with fusion protein, HBcAg or PBS, the titers of antibody in BALB/c mice immunized with fusion protein reached 2.75 x 10(5). Western blot analysis demonstrated that the fusion protein had specific antigenicity against anti-EGFRvIII antibody. Further observation showed fusion protein induced a high frequency of IFN-gamma-secreting lymphocytes. CD4+T cells rather than CD8+T cells were associated with the production of IFN-gamma. Using Renca-vIII(+) cell as specific stimulator, we observed remarkable cytotoxic activity in splenocytes from mice immunized with fusion protein. Mice were challenged with Renca-vIII(+) cells after five times immunization. In fusion protein group, three of ten mice failed to develop tumor and all survived at the end of the research. The weight of tumors in fusion protein were obviously lighter than that in other two groups (t = 4.73, P = 0.044; t = 6.89, P = 0.040). These findings demonstrated that EGFRvIII-HBcAg fusion protein triggered protective responses against tumor expressing EGFRvIII.