Simultaneous detection of multiple microRNAs based on fluorescence resonance energy transfer under a single excitation wavelength.

MicroRNAs (miRNAs) play a key role in physiological processes, and their dysregulation is closely related to various human diseases. Simultaneous detection of multiple miRNAs is pivotal to cancer diagnosis at an early stage. However, most multicomponent analyses generally involve multiple excitation wavelengths, which are complicated and often challenging to simultaneously acquire multiple detection signals. In this study, a convenient and sensitive sensor was developed to simultaneously detection of multiple miRNAs under a single excitation wavelength through the fluorescence resonance energy transfer between the carbon dots (CDs)/quantum dots (QDs) and graphene oxide (GO). A hybridization chain reaction (HCR) was triggered by miRNA-141 and miRNA-21, resulting in the high sensitivity with a limit of detection (LOD) of 50 pM (3σ/k) for miRNA-141 and 60 pM (3σ/k) for miRNA-21. This simultaneous assay also showed excellent specificity discrimination against the mismatch. Furthermore, our proposed method successfully detected miRNA-21 and miRNA-141 in human serum samples at a same time, indicating its diagnostic potential in a clinical setting.

[Expression of Fas protein in myocardiac tissue of viral myocarditis and dilated cardiomyopathy].

OBJECTIVE: To study the pathogenesis of viral myocarditis (VMC) and dilated cardiomyopathy (DCM) and their relationship. METHODS: Sixty samples including 20 VMC, 20 DCM and 20 controls were collected. The expression of Fas protein in myocardium of each group was detected by modified immunohistochemistry with unequivocal brown staining in the myocardial membrane scored as positive, and the results of positive reaction were analyzed by Ridit test. RESULTS: Fas protein expression increased obviously in VMC and DCM groups as compared with that of the control group. The difference of positive results between each group analyzed by Ridit test was statistically significant (P<0.005). Statistically significant differences were found between VMC and control groups as well as between DCM and control groups (P<0.05), but not between VMC and DCM groups (P>0.05) by multiple comparison Ridit test. CONCLUSION: The expression of Fas protein is significantly higher in the VMC and DCM groups than in that of the control group. These results suggest that both the VMC and DCM may share a similar pathogenesis, which most likely involves cell apoptosis.