ObjectiveTo explore the diagnostic value of plasma (1, 3)-β-D-glucan test (G test) in diagnosis of invasive fungal infections (IFI) and the influence of albumin on G test.Methods A prospective observational study was conducted. 267 patients admitted to medical intensive care unit (MICU) of Dalian Municipal Central Hospital from January 21st, 2012 to October 31st, 2014 were enrolled. According to IFI guideline, the patients were divided into without IFI group (n= 35), possible IFI group (n = 70), hypotheticle IFI group (n = 145) and proven IFI group (n = 17). G test was examined routinely using microbiology kinetic rapid reader MB-80.The different threshold values were calculated on G test. The difference among G tests, fungal culture and clinical diagnosis were compared. The results of G test ahead of and post albumin administration in each group were compared, and the value of G test for diagnosis of IFI during albumin infusion was evaluated.Results When the cut-off value was 20 ng/L for IFI diagnosis, higher sensitivity (79.8%), specificity (87.9%), and Youden index (67.7%) were found. The positive rates of G test, fungal culture and clinical diagnosis of IFI were 57.7% (154/267), 60.7% (162/267) and 54.3%(145/267) respectively, without showing significant differences (allP> 0.05). The result of G test (ng/L) was not obviously changed after albumin administration compared with that before in without IFI, possible IFI, hypotheticle IFI, and proven IFI groups (without IFI group: 11.25±2.33 vs. 10.99±1.07,t= -1.723,P= 0.085; possible IFI group: 53.14±5.53 vs. 49.22±8.11,t= -0.395,P= 0.693; hypotheticle IFI group: 90.30±9.38 vs. 85.41±10.11, t= 710.500,P= 0.860; proven IFI group: 100.98±19.24 vs. 103.21±17.66,t= 653.000,P= 0.449). Prior to the administration of albumin, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Youden index were 79.8%, 87.9%, 45.6%, 96.7%, 67.7%, respectively. However, after the administration of albumin, they were 81.5%, 85.7%, 44.8%, 96.5%, and 67.2%, respectively, without significant difference.Conclusions G test is method for early diagnosis of IFI. The sensitivity and specificity are higher with 20 ng/L as the critical value. The result of G test is not interfered by albumin administration.

Objective:To express human epididymis protein 4 (HE4) in prokaryotic cells,purify the expressed product and de-termine its activity by immunoassay kit.Methods: The gene encoding HE 4 was cloned using RT-PCR technique from total RNA of ovarian carcinoma cells ES-2,the amplified HE4 gene was cloned into prokaryotic expression vector pGEX-4T-1 and PET26b respective-ly.The recombinant plasmid pGEX-4T-1-HE4 and PET26b-HE4 were constructed and transformed into E.coli BL21 cells respectively, and protein ( GST-HE4 and His-HE4 ) expressions were induced by IPTG and identified by SDS-PAGE and commercial ELISA kit.Results:Restriction analysis and sequencing proved that recombinant plasmid pGEX -4T-1-HE4 and PET26b-HE4 were constructed correctly.The expressed recombinant proteins ,with the relative molecular mass of about 38 000 and 12 000 ,showed specific binding to monoclonal antibody against HE 4.Conclusion:Two kinds of recombinant HE 4 protein are successfully expressed in prokaryotic cells , which laid a foundation of preparation of immunoassay reagents.

Objective To construct an eukaryotic expression vector of human telomerase reverso transcriptase (hTERT) gene specific shRNA, and investigate the effect of pshRNA-hTERT combined with γ-irradiation on telomerase activity and DNA damage. Methods The recombinant expression plasmid pshRNA-hTERT was constructed and transfected into Hep-2 cells. The telomerase activity was examined by the PCR-hased telomeric repeat amplification protocol (TRAP). DNA single-stranded break (SSB) and the DNA double-stranded break (DSB) were detected by Comet assay. The xenograft model of human laryngeal carcinoma with the same genetic background and different radiosensitivity (Hep-2 and Hep-2R) was established in nude mice. The mixture of pshRNA-hTERT and liposome was injected to the transplanted tumor to observe the inhibition of the tumor growth. The cell apoptosis was detected by TUNEL. The hTERT protein expression was determined by streptavidin-peroxidase conjugated method (AP). Results Recombinant expression plasmid pshRNA-hTERT was successfully constructed and transfected into Hep-2 cells. The hTERT expression inhibition rate reached 60.78 %. pshRNA-hTERT not only inhibited telomerase activity of Hep-2 inehiding the increase of telomerase activity induced by γ-irradiation, but also inhibited the repair of the SSB and DSB induced by irradiation in the human laryngeal carcinoma xenograft in nude mice with the same genetic background and different radiosensitivity. The pshRNA-hTERT combined with γ-irradiation could inhibit the growth of transplanted tumor (Hep-2: EPO = 1.79; Hep-2R: EPO = 2.01) with reduced telomerase activity and hTERT protein expression. Conclusions The eukaryotic expression vector pshRNA-hTERT could enhance the radiosensitivity of Hep-2 cells in vitro and the human laryngeal carcinoma xenograft in nude mice which had the same genetic background with different radiosensitivity.