Weiping Lu

Rapid and effective diagnosis of tuberculosis and rifampicin resistance with Xpert MTB/RIF assay: A meta-analysis

OBJECTIVES Xpert MTB/RIF (Cepheid) assay has been introduced for the diagnosis of tuberculosis (TB) and RIF-resistance. The meta-analysis was used to establish the overall accuracy of Xpert MTB/RIF assay for diagnosing TB and RIF-resistance. METHODS Based on comprehensive searches of the Pubmed and Embase, we identified outcome data from all articles estimating diagnostic accuracy with Xpert MTB/RIF assay. A summary estimation for sensitivity, specificity, diagnostic odds ratios (DOR) and the area under the summary ROC curve (AUC) was calculated by using the bivariate random-effects approach. RESULTS The meta-analysis included 18 studies (10,224 suspected specimens). The summary estimate was 90.4% (95%CI 89.2%-91.4%) for sensitivity, 98.4% (95%CI 98.0%-98.7%) for specificity and 328.3/0.9822 for DOR/AUC in pulmonary tuberculosis (PTB). The sensitivity, specificity and DOR/AUC of detecting RIF-resistance were 94.1%, 97.0% and 177.8/0.9832, respectively. For extrapulmonary tuberculosis, the overall pooled sensitivity was 80.4% and specificity was 86.1%. The findings in subgroup analysis were as follows: the accuracy of Xpert MTB/RIF assay is higher in smear-positive specimens and the sensitivity of diagnosing PTB in adults was higher than that in children (90.8% versus 74.3%). CONCLUSIONS TB and RIF-resistance can be rapidly and effectively diagnosed with Xpert MTB/RIF assay.

Does risk for ovarian malignancy algorithm excel human epididymis protein 4 and CA125 in predicting epithelial ovarian cancer: a meta-analysis.

BackgroundsRisk for Ovarian Malignancy Algorithm (ROMA) and Human epididymis protein 4 (HE4) appear to be promising predictors for epithelial ovarian cancer (EOC), however, conflicting results exist in the diagnostic performance comparison among ROMA, HE4 and CA125.MethodsRemote databases (MEDLINE/PUBMED, EMBASE, Web of Science, Google Scholar, the Cochrane Library and ClinicalTrials.gov) and full texts bibliography were searched for relevant abstracts. All studies included were closely assessed with the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2). EOC predictive value of ROMA was systematically evaluated, and comparison among the predictive performances of ROMA, HE4 and CA125 were conducted within the same population. Sensitivity, specificity, DOR (diagnostic odds ratio), LR ± (positive and negative likelihood ratio) and AUC (area under receiver operating characteristic-curve) were summarized with a bivariate model. Subgroup analysis and sensitivity analysis were used to explore the heterogeneity.ResultsData of 7792 tests were retrieved from 11 studies. The overall estimates of ROMA for EOC predicting were: sensitivity (0.89, 95% CI 0.84-0.93), specificity (0.83, 95% CI 0.77-0.88), and AUC (0.93, 95% CI 0.90-0.95). Comparison of EOC predictive value between HE4 and CA125 found, specificity: HE4 (0.93, 95% CI 0.87-0.96) > CA125 (0.84, 95% CI 0.76-0.90); AUC: CA125 (0.88, 95% CI 0.85-0.91) > HE4 (0.82, 95% CI 0.78-0.85). Comparison of OC predictive value between HE4 and CA125 found, AUC: CA125 (0.89, 95% CI 0.85-0.91) > HE4 (0.79, 95% CI 0.76-0.83). Comparison among the three tests for EOC prediction found, sensitivity: ROMA (0.86, 95%CI 0.81-0.91) > HE4 (0.80, 95% CI 0.73-0.85); specificity: HE4 (0.94, 95% CI 0.90-0.96) > ROMA (0.84, 95% CI 0.79-0.88) > CA125 (0.78, 95%CI 0.73-0.83).ConclusionsROMA is helpful for distinguishing epithelial ovarian cancer from benign pelvic mass. HE4 is not better than CA125 either for EOC or OC prediction. ROMA is promising predictors of epithelial ovarian cancer to replace CA125, but its utilization requires further exploration.

Label-free and high-sensitive detection of human breast cancer cells by aptamer-based leaky surface acoustic wave biosensor array

A label-free and high-sensitive sensing technology for tumor cell recognition and detection was developed based on a novel 2 × 3 model of leaky surface acoustic wave (LSAW) aptasensor array. In this methodology, every resonator crystal unit of the LSAW aptasensor array had an individual oscillator circuit to work without mutual interference, and could oscillate independently with the phase shift stability of ± 0.15° in air phase and ± 0.3° in liquid phase. The aptamer was firstly assembled to the gold electrode surface of 100 MHz LiTaO3 piezoelectric crystal, which could effectively captured target cells (MCF-7 cells) based on the specific interaction between aptamer and the overexpression of MUC1 protein on tumor cell surface. The aptamer-cell complexes increased the mass loading of LSAW aptasensor and led to phase shifts of LSAW. The plot of phase shift against the logarithm of concentration of MCF-7 cells was linear over the range from 1 × 10(2) cells mL(-1) to 1 × 10(7) cells mL(-1) with a correlation coefficient of 0.994. The detection limit as low as 32 cells mL(-1) was achieved for MCF-7 cells. The LSAW aptasensor also exhibited excellent specificity and stability. In addition, this aptasensor could be regenerated for ten times without irreversible loss of activity. Therefore, the LSAW aptasensor may offer a promising approach for tumor cell detection and have great potential in clinical applications.

Association of DNA repair gene XRCC1 and XPD polymorphisms with genetic susceptibility to gastric cancer in a Chinese population.

BACKGROUND DNA repair gene polymorphisms can contribute to susceptibility of human cancer, including gastric cancer. Three single nucleotide polymorphisms (SNPs) of xeroderma pigmentosum group D (XPD) and X-ray repair cross complement 1 (XRCC1) genes were genotyped in gastric cancer and control subjects in a population from Southwestern China for their association with susceptibility of gastric cancer risk. METHODS 190 hospital-based cases and 180 matched controls were recruited and blood samples were collected from each of them and amplified with a PCR and DNA sequenced for XPD Asp312Asn, XRCC1 Arg194Trp, and XRCC1 Arg280Gln genotyping. RESULTS Allelic association analysis of these three SNPs showed that the frequency of XRCC1 194Trp in gastric cancer case and the control was 17.2% and 7.3%, respectively, which was significantly associated with gastric cancer risk (OR=2.72, 95% CI: 1.04-7.24, p=0.027). Furthermore, XRCC1 194Trp allele increased gastric carcinoma risk in male patients with older age and distant metastasis of gastric cancer. In addition, XRCC1 Trp allele but not XRCC1 Arg allele was closely associated to development of gastric cardia carcinoma. However, other SNPs did not show an association with gastric cancer risk or other clinicopathologic data of the patients. CONCLUSION XRCC1 194Trp allele significantly increased the risk of gastric cancer and also associated with risk of gastric cardia carcinoma and promoted distant metastasis of gastric cancer. Future study will verify these findings for use of this SNP as biomarker in gastric cancer.

Association of tuberculosis and polymorphisms in the promoter region of macrophage migration inhibitory factor (MIF) in a Southwestern China Han population.

The macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays an important role in the pathogenesis of immune diseases. High levels of MIF have been detected in the sera of patients with tuberculosis (TB), and it has been proposed that MIF gene polymorphisms may influence the risk of developing TB. The aim of this study was to evaluate the potential relationship between functional polymorphisms of MIF and TB in a Han population from Southwestern China. TB patients (n=215) and healthy unrelated controls (n=245) were recruited for this study. Genomic DNA was isolated from all the participants. The MIF-173 G/C SNP was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The MIF-794 CATT(5-8) microsatellite was evaluated by direct sequencing of the subsequent PCR products. Association analysis of the two polymorphisms showed that the frequency of -173 (GC+CC) in TB patients and controls was 49.3% and 31.4%, respectively, which was statistically significant (OR=2.12, 95% CI=1.45-3.10, P<0.001); the frequencies of -794 (7/X+8/X) were 56.7% and 45.3%, respectively, also statistically significant between the TB and healthy controls (OR=1.58, 95% CI=1.10-2.29, P=0.015). In summary, Genetic variation in the MIF gene is closely associated with tuberculosis. Both the 173 (GC+CC) SNP and -794 (7/X+8/X) microsatellite increased the risk of Chinese Han developing TB.

Detection of single-nucleotide polymorphisms with novel leaky surface acoustic wave biosensors, DNA ligation and enzymatic signal amplification.

This manuscript describes a new technique for detecting single-nucleotide polymorphisms (SNPs) by integrating a leaky surface acoustic wave (LSAW) biosensor, enzymatic DNA ligation and enzymatic signal amplification. In this technique, the DNA target is hybridized with a capture probe immobilized on the surface of a LSAW biosensor. Then, the hybridized sequence is ligated to biotinylated allele-specific detection probe using Taq DNA ligase. The ligation does not take place if there is a single-nucleotide mismatch between the target and the capture probe. The ligated detection probe is transformed into a streptavidin-horseradish peroxidase (SA-HRP) terminal group via a biotin-streptavidin complex. Then, the SA-HRP group catalyzes the polymerization of 3,3-diaminobenzidine (DAB) to form a surface precipitate, thus effectively increasing the sensitivity of detecting surface mass changes and allowing detection of SNPs. Optimal detection conditions were found to be: 0.3 mol/L sodium ion concentration in PBS, pH 7.6, capture probe concentration 0.5 μmol/L and target sequence concentration 1.0 μmol/L. The detection limit was found to be 1 × 10(-12)mol/L. Using this technique, we were able to detect a single-point mutation at nucleotide A2293G in Japanese encephalitis virus.

Association between CD209 -336A/G and -871A/G Polymorphisms and Susceptibility of Tuberculosis: A Meta-Analysis

Background The association between CD209 promoter polymorphisms (-336A/G, -871A/G) and tuberculosis (TB) risk has been widely reported, but results of previous studies remain controversial and ambiguous. To assess the association between CD209 polymorphisms and TB risk, a meta-analysis was performed. Methods Based on comprehensive searches of the PubMed, Embase, Web of Science, Weipu, and CBM databases, we identified outcome data from all articles estimating the association between CD209 polymorphisms and TB risk. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated. Results A total of 14 studies with 3,610 cases and 3,539 controls were identified. There was no significant association between CD209 -336A/G polymorphism and TB risk (OR = 1.04, 95% CI = 0.91–1.19 for G vs. A; OR = 1.13, 95% CI = 0.84–1.53 for GG vs. AA; OR = 1.04, 95% CI = 0.87–1.24 for GG+AG vs. AA; OR = 1.11, 95% CI = 0.88–1.39 for GG vs. AG+AA). However, the significant association was revealed for Asians in GG vs. AA (OR = 2.48, 95% CI = 1.46–4.22, P = 0.0008) and GG vs. AG+AA (OR = 2.10, 95% CI = 1.33–3.32, P = 0.001). For the CD209 -871A/G polymorphism, lack of an association was also found (OR = 0.81, 95% CI = 0.70–0.95 for G vs. A; OR = 1.00, 95% CI = 0.52–1.93 for GG vs. AA; OR = 0.73, 95% CI = 0.60–0.89 for GG+AG vs. AA; OR = 1.09, 95% CI = 0.57–2.10 for GG vs. AG+AA). Conclusion The present meta-analysis suggested that CD209 promoter polymorphisms (-336A/G, -871A/G) were unlikely to substantially contribute to TB susceptibility. However, the GG genotype of CD209 -336A/G polymorphism might be a genetic risk factor that increases TB susceptibility for Asians in GG vs. AA and GG vs. AG+AA.

Development and validation of a novel leaky surface acoustic wave immunosensor array for label-free and high-sensitive detection of cyclosporin A in whole-blood samples

This manuscript described a novel 2×3 model of leaky surface acoustic wave (LSAW) immunosensor array for label-free and high-sensitive detection of Cyclosporin A (CsA) in whole-blood samples. In this technique, every resonator crystal unit of the LSAW immunosensor array had an individual oscillator circuit to work without mutual interference. The LSAW immunosensor was first immobilized with protein A from Staphylococcus aureus and monoclonal anti-CsA antibody on the gold electrode surface of 100 MHz LiTaO3 piezoelectric crystals, which then captured the CsA. The CsA increased the mass loading of LSAW immunosensor and leaded to phase shifts of LSAW. Consequently, under optimal conditions, the designed LSAW immunosensor exhibited a detection limit of 0.89 ng/mL, quantification limit of 2.96 ng/mL, and wide dynamic linear range from 1 ng/mL to 1000 ng/mL for CsA detection. Application of the LSAW immunosensor array to clinical sample revealed that consistency and comparability between LSAW immunosensor and the enzyme multiplied immunoassay method were good. Moreover, the immunosensor could be regenerated for ten times without appreciable loss of activity. Therefore, the self-designed LSAW immunosensor array provided a rapid, accurate, label-free, easy handling, and dynamic real-time method for the detection of immunosuppressive drugs in clinical laboratory.

Rapid urinary trypsinogen-2 test in the early diagnosis of acute pancreatitis: A meta-analysis

OBJECTIVES Urinary trypsinogen-2 has been implicated as a promising biomarker for the early diagnosis of acute pancreatitis (AP). The meta-analysis was used to establish the overall accuracy of urinary trypsinogen-2 test for diagnosing AP. METHODS Based on comprehensive searches of the PubMed and Embase databases, we identified and abstracted outcome data from all articles evaluating the diagnostic value of urinary trypsinogen-2. A summary estimate for sensitivity, specificity, 95% confidence region and 95% prediction region was calculated using the bivariate random-effects approach. RESULTS The meta-analysis included 13 studies (2342 patients, the proportion of severe AP from 13.21% to 30.00%). Overall, the pooled sensitivity was 82.3% (95%CI 79.3%-85.1%) and specificity was 93.5% (95%CI 92.2%-94.6%). The diagnostic odds ratios (DOR) was 85.23 (95%CI 40.14-180.99). The area under the summary ROC curve (AUC) was 0.9673. CONCLUSION The urinary trypsinogen-2 test is a reliable and rapid method for the early diagnosis of AP.

Melioidosis Acquired by Traveler to Thailand: A Case Report

Background: Burkhalter pseudomallei (B. pseudomallei) is a gram-negative, saprophytic bacillus found in soil and water, and it is endemic in the tropical and subtropical areas. Melioidosis is a rare infection caused by B. pseudomallei, and it occurs only sporadically in travellers returning from disease-endemic areas. Severe clinical disease is seen mostly in patients with alteration of immune status, especially related to diabetes. To our best knowledge, this is the first reported case of melioidosis in a traveller complicated by diabetes in Chongqing, China. Case presentation: A 55-year-old man with diabetes presented with erosions and ulcers on right leg with purulent discharge and painful sensation for a one-month history. On presentation she had high fever and urinary tract infection, then developed pneumonia, soon after his return from Thailand to China. Cultures from different specimens including blood cultures and urine cultures turned out positive, and then the organisms were finally identified as B. pseudomallei, thus the patient’s treatment was switched to intravenous meropenem. Subsequently, the patient’s urinary tract infection and fever resolved, and after 15 days of receiving meropenem, his general condition improved. Conclusions: Given the frequency of travel between China and other countries, the existence of imported cases from endemic countries until now is striking, and physicians should be aware of its varied manifestations. In particular, melioidosis should be considered when diabetic patients returning from endemic countries, even without risk factors predisposing to severe disease.