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Background Measurement uncertainty (MU) is a metrological concept, which can be used for objectively estimating the quality of test results in medical laboratories. The Nordtest guide recommends an approach that uses both internal quality control (IQC) and external quality assessment (EQA) data to evaluate the MU. Bootstrap resampling is employed to simulate the unknown distribution based on the mathematical statistics method using an existing small sample of data, where the aim is to transform the small sample into a large sample. However, there have been no reports of the utilization of this method in medical laboratories. Thus, this study applied the Nordtest guide approach based on bootstrap resampling for estimating the MU. Methods We estimated the MU for the white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb), and platelets (Plt). First, we used 6 months of IQC data and 12 months of EQA data to calculate the MU according to the Nordtest method. Second, we combined the Nordtest method and bootstrap resampling with the quality control data and calculated the MU using MATLAB software. We then compared the MU results obtained using the two approaches. Results The expanded uncertainty results determined for WBC, RBC, Hb, and Plt using the bootstrap resampling method were 4.39%, 2.43%, 3.04%, and 5.92%, respectively, and 4.38%, 2.42%, 3.02%, and 6.00% with the existing quality control data ( U [ k = 2]). For WBC, RBC, Hb, and Plt, the differences between the results obtained using the two methods were lower than 1.33%. The expanded uncertainty values were all less than the target uncertainties. Conclusions The bootstrap resampling method allows the statistical analysis of the MU. Combining the Nordtest method and bootstrap resampling is considered a suitable alternative method for estimating the MU.

To measure the levels of B-lymphocyte stimulator (BLyS) and its receptors mRNA expression in peripheral blood mononuclear cells (PBMCs) using quantitative real-time polymerase chain reaction (PCR) method and to investigate the relationship between BLyS and its receptors mRNA expression and systemic lupus erythematosus (SLE).Specific primers and TaqMan probe were designed, and real-time PCR was performed. According to the standard curve of plasmids DNA, the levels of BLyS and its receptors mRNA expression in 37 patients with SLE and 30 healthy subjects were determined. The ratio of the expression levels of BLyS mRNA to that of beta2-microglobulin (beta2M) mRNA and the ratio of the expression levels of BLyS receptors mRNA to that of beta2M mRNA were regarded as indicator for the levels of BLyS and its receptors mRNA expression.The expression of BLyS, TACI and BAFF-R mRNA in PBMCs from patients with SLE was significantly elevated compared to healthy controls (P0.001 for each), and active patients with SLE group had higher mRNA expression than patients with SLE inactive group (P0.001 for each). The patients with elevated anti-double-stranded DNA (anti-dsDNA) antibody titers had enhanced BLyS, TACI and BAFF-R mRNA expression (P0.05 for BLyS; and P0.01 for TACI and BAFF-R).The BLyS, TACI and BAFF-R mRNA expression levels were significantly elevated in patients with SLE, which suggests that BLyS, TACI and BAFF-R might be involved in the pathogenesis, and that mRNA expression levels might serve as a biomarker of disease activity.

The purpose of our study was to investigate the serum levels of soluble a-proliferation-inducing ligand (sAPRIL) in patients with colorectal cancer (CRC), benign intestinal disease and healthy volunteers and explore the potential possibility of sAPRIL severing as a CRC biomarker.Our investigation was conducted on 35 blood samples obtained from CRC patients, 32 blood samples from patients with benign intestinal diseases and 31 blood samples from healthy volunteers. The sAPRIL concentrations were examined by an enzyme-linked immunosorbent assay (ELISA) and data were analyzed with non-parametric Mann-Whitney U-test and X²-test. The correlation relationship between sAPRIL and CEA, as well as sAPRIL and CA19-9 was assessed by non-parametric Spearmen's correlation test, respectively.The median value of sAPRIL in the malignant group was 10.43 ng/mL, compared with those of the benign group (4.89 ng/mL) and control group (3.30 ng/mL), respectively, which had an obvious significance (P0.0003). Area under the receiver-operating characteristic (ROC) curve for sAPRIL was 0.854 (95% CI, 0.776-0.933). The optimal cut-off level of sAPRIL was 5.49 ng/mL. Serum sAPRIL had a positive correlation with CEA (r=0.637, P=0.000) and CA19-9 (r=0.357, P=0.008) in 35 patients with colorectal cancer. sAPRIL showed higher sensitivity (82.9%) than those of CEA (74.3%) and CA19-9 (65.7%) in CRC, respectively.The results indicated that serum sAPRIL, as a potential biomarker, had a positive diagnostic value for colorectal cancer.

Many patients with colorectal cancer (CRC) present with regional or widespread metastasis, partially reflecting limitations of the current screening programs. This study was aimed to find a complementary marker that can improve the diagnostic accuracy.Concentrations of cell-free DNA based on Alu (Alu-based CFD) in 31 unselected CRC patients, 30 intestinal polyp patients and 92 healthy individuals were detected by branch DNA (bDNA). Concentrations of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were detected by ARCHITECT assay.There was significant difference in concentrations of CFD between CRC and intestinal polyp patients or healthy individuals (P0.0001). There was no statistically significant difference in CFD in different subgroups of CRC patients with respect to gender, age, tumor site and pathologic stage, suggesting that CFD might be an independent marker relative to CEA and CA19-9. There was a significant correlation between pathologic stage and CEA or CA19-9. Although no significant correlation was observed between pathologic stage and CFD, CFD (the area under the receiver operating characteristic curve (AUC)=0.904) seemed to be a better indicator to distinguish CRC patients from intestinal polyp patients as compared with CEA (AUC=0.681) or CA19-9 (AUC=0.651). CFD was more accurate than CEA or CA19-9 in diagnosing CRC.Combination of CFD, CEA and CA19-9 may be a better option for the diagnosis of CRC than any of them used alone. Discrimination CRC from intestinal polyp patients with CFD and staging with CEA and CA19-9 may substantially improve the accuracy CRC diagnosis.

Objectives Human cell-free circulating DNA (cf-DNA) derived mainly from cell apoptosis and necrosis can be measured by a variety of laboratory techniques, but almost all of these methods require sample preparation. We have developed a branched DNA (bDNA)-based Alu assay for quantifying cf-DNA in myocardial infarction (MI) patients. Design and methods A total of 82 individuals were included in the study; 22 MI and 60 normal controls. cf-DNA was quantified using a bDNA-based Alu assay. Results cf-DNA was higher in serum compared to plasma and there was a difference between genders. cf-DNA was significantly higher in MI patients compared to the controls. There was no correlation between cf-DNA and creatine kinase-MB (CK-MB), troponin I (cTnI) or myoglobin (MYO). In serial specimens, cf-DNA was sensitive and peaked earlier than cTnI. Conclusions The bDNA-based Alu assay is a novel method for quantifying human cf-DNA. Increased cf-DNA in MI patients might complement cTnI, CK-MB and MYO in a multiple marker format.

Objective The objective of this study was to investigate the effect of knockdown of Livin expression on reversing drug resistance phenotype of colon cancer HCT-8/V cells. Design and methods Specific short hairpin RNA (shRNA) was chosen and transfected in human colon cancer HCT-8/V cell line. Cell apoptosis and chemosensitivity were evaluated following downregulation of Livin expression. Results In the current study, Livin was found to be highly expressed in the HCT-8/V colon cancer cells, which were resistant to several anti-tumor drugs. Knocking down of Livin expression in HCT-8/V cells by specific RNAi facilitated the apoptosis of HCT-8/V cells in response to vincristine (VCR), etoposide (VP-16), and 5-flourouracil (5-FU). Chemosensitivity assay confirmed the results and demonstrated the reversal of drug resistance phenotype of HCT-8/V cells. Conclusion These data suggest that specific silencing of Livin gene expression could be a promising target for further research in clinical chemotherapy of colon cancer.

Objective: The purpose of this study was to investigate the function of a proliferation-inducing ligand (APRIL) gene among the metastatic colorectal cancer (CRC) disease. Methods: Cell adhesion, cell migration and invasion behavior were detected after knockdown of APRIL expression in the colon carcinoma cell line, SW480 by RNAi and the rescue experiments were performed with recombinant human APRIL (rhAPRIL) in vitro. Results: This original study indicated that knockdown of APRIL expression strongly inhibited colon carcinoma cell adhesion, cell migration and invasion in vitro. By contrast, reconstitution of APRIL expression with rhAPRIL in these APRILi cells, prominently restores CRC cell migration and invasion. Conclusion: These results strongly suggest that APRIL play an important role in the tumor development of the invasive or migratory behavior of CRC cells and may be a useful therapeutic target in the malignant colon carcinomas.

Objectives To measure the expression levels of B-lymphocyte stimulator (BLyS) and its receptors in multiple myeloma (MM), and to investigate the relationship between them. Design and methods BLyS and its receptors mRNA levels from peripheral blood mononuclear cells (PBMCs) of 31 MM patients and 30 healthy controls were determined by real-time PCR. The results were presented as the ratios of target genes, to β2-microglobulin (β2M), mRNA. BLyS serum level was determined by enzyme-linked immunosorbent assay (ELISA). Results The circulating levels of BLyS in 31 MM patients were significantly elevated and correlated with the levels of Lactate dehydrogenase (LDH). More importantly, 93.55% (29/31) and 90.32% (28/31) of these MM patients had significantly higher expression levels of BLyS and BCMA mRNA respectively, which are correlated with the levels of LDH, while 64.52% (20/31) of these MM patients had significantly lower expression levels of TACI mRNA. Conclusion BLyS protein concentration and BLyS, TACI and BAFF-R mRNA expression levels were significantly elevated in patients with MM, suggesting that BLyS, TACI and BAFF-R may be involved in the pathogenesis of MM, and that expression levels could serve as a biomarker of prognosis.