Comparison of methods for detecting asymptomatic malaria infections in the China-Myanmar border area.

BACKGROUND: Sensitive methods for detecting asymptomatic malaria infections are essential for identifying potential transmission reservoirs and obtaining an accurate assessment of malaria epidemiology in low-endemicity areas aiming to eliminate malaria. PCR techniques to detect parasite nucleic acids (DNA or RNA) are among the most commonly used molecular methods. However, most of these methods are of low throughput and cannot be used for large-scale molecular epidemiological studies. A recently developed capture and ligation probe-PCR (CLIP-PCR) is claimed to have the sensitivity of molecular techniques and the high throughput capacity needed for screening purposes. This study aimed to compare several molecular methods for detecting asymptomatic and submicroscopic Plasmodium infections in healthy residents of a malaria-hypoendemic region in Southeast Asia, where malaria elimination is in sight. METHOD: This study compared three molecular detection methods side-by-side, namely nested PCR targeting the rRNA genes, nested RT-PCR to detect parasite rRNA, and CLIP-PCR to detect parasite rRNA in 1005 healthy individuals in northeastern Myanmar. For nested PCR and RT-PCR, parasite DNA and total RNA were extracted from ~100 µL of blood, whereas RNA used for CLIP-PCR was from a 3 mm disk of dried blood filter paper. The sensitivity and specificity of these methods were compared with those of conventional light microscopy. In addition, RT-PCR and quantitative RT-PCR (qRT-PCR) targeting the Pvs25 gene in Plasmodium vivax were used to assess gametocyte prevalence in the samples. RESULTS: Light microscopy detected Plasmodium infections in only 1.19% of the residents harbouring the parasites. CLIP-PCR had slightly better performance and detected Plasmodium infections in 1.89% of the population. Further improvement was achieved by nested PCR to detect parasite DNA, which detected P. vivax and Plasmodium falciparum infections in 2.39% of the residents. The nested RT-PCR targeting rRNA, however, detected as many as 187 (18.61%) individuals having Plasmodium infections with P. vivax being the predominant species (176 P. vivax, 5 P. falciparum and 6 P. falciparum/P. vivax mixed infections). Of the 210 Plasmodium-positive samples detected by all molecular methods, 115 were Pvs25-positive by qRT-PCR, indicating that a large proportion of asymptomatic individuals were gametocyte carriers. CONCLUSION: Nested RT-PCR based on the detection of asexual-stage parasite rRNA was the most sensitive, with a more than sixfold higher sensitivity than the other two molecular methods of parasite detection. CLIP-PCR has an increased throughput, but its sensitivity in this study was much lower than those of other molecular methods, which may be partially due to the smaller amount of RNA input used.

Prognostic significance of ß-catenin expression in patients with ovarian cancer: A meta-analysis.

AIM: The purpose of this study was to evaluate the impact of ß-catenin immunohistochemical expression on the prognostic of ovarian cancer (OC) for that ß-catenin could be responsible for the development and progress of OC. METHODS: We searched various databases to identify eligible studies, and Review Managers 5.2 software was fulfilled in the meta-analysis. RESULTS: A total of 11 studies were defined and composed in 1858 cases. ß-catenin expression was significantly correlated with poor overall survival (OS) in OC patients (HR: 2.48, 95% CI: 1.38-4.47, P = 0.003), and showed a significant degree of heterogeneity (I2 = 83%, P < 0.00001). Subgroup analysis indicated that accumulation in the nucleus and/or cytoplasm, rather than membrane, considerably influences the survival of OC patients independently. CONCLUSION: Nucleus and/or cytoplasma of ß-catenin expression might be associated with tumor progression and could be a possible potential predictive factor of poor prognosis in OC patients.

Matrix metalloproteinase-14 induces epithelial-to-mesenchymal transition in synovial sarcoma.

Synovial sarcoma (SS) is a highly aggressive malignant soft tissue sarcoma with typical characteristics of both epithelial and mesenchymal differentiation. Matrix metalloproteinase-14 (MMP-14) is reported to play an important role in some of these tumors. It induces epithelial-to-mesenchymal transition (EMT) in some carcinomas, such as breast and prostate cancers. However, the role of MMP-14 in the pathogenesis of SS remains unclear. Therefore, we investigated the role of MMP-14 and EMT/mesenchymal-to-epithelial transition in SS. The expression of MMP-14 and EMT-related proteins was determined in 37 SS cases and transfected cells by immunohistochemistry staining and Western blotting. The invasion ability of transfected cells was determined by transwell invasion assay. The expression rates of MMP-14, E-cadherin, N-cadherin, and vimentin were 75.7%, 54.1%, 75.7%, and 100%, respectively, in the cases of SS. The expression of MMP-14 correlated negatively with E-cadherin and positively with N-cadherin in monophasic fibrous SS. The MMP-14 protein expression was higher in stage III/IV than in stage I/II. After MMP-14 was transfected into SW982 cells, MMP-14, N-cadherin, and vimentin expression was up-regulated, and E-cadherin expression was down-regulated. High expression of MMP-14 enhanced the invasive ability of SW982 cells. Our findings suggest that MMP-14 enhances the invasive ability of SW982 cells by inducing EMT. By this action, it may play an important role in the occurrence and development of SS.