Plasmonic molecular assays： Recent advances and applications for mobile health

Plasmonics-based biosensing assays have been extensively employed for biomedical applications. Significant advancements in use of plasmonic assays for the construction of point-of-care （POC） diagnostic methods have been made to provide effective and urgent health care of patients, especially in resource- limited settings. This rapidly progressive research area, centered on the unique surface plasmon resonance （SPR） properties of metallic nanostructures with exceptional absorption and scattering abilities, has greatly facilitated the development of cost-effective, sensitive, and rapid strategies for disease diagnostics and improving patient healthcare in both developed and developing worlds. This review highlights the recent advances and applications of plasmonic technologies for highly sensitive protein and nucleic acid biomarker detection. In particular, we focus on the implementation and penetration of various plasmonic technologies in conventional molecular diagnostic assays, and discuss how such modification has resulted in simpler, faster, and more sensitive alternatives that are suited for point-of-use. Finally, integration of plasmonic molecular assays with various portable POC platforms for mobile health applications are highlighted.

Affinity peptide developed by phage display selection for targeting gastric cancer

AIM:To develop an affinity peptide that binds to gastric cancer used for the detection of early gastric cancer.METHODS:A peptide screen was performed by biopanning the PhD-12 phage display library,clearing non-specific binders against tumor-adjacent normal appearing gastric mucosa and obtaining selective binding against freshly harvested gastric cancer tissues.Tumortargeted binding of selected peptides was confirmed by bound phage counts,enzyme-linked immunosorbent assay,competitive inhibition,fluorescence microscopy and semi-quantitative analysis on immunohistochemistry using different types of cancer tissues.RESULTS:Approximately 92.8% of the non-specific phage clones were subtracted from the original phage library after two rounds of biopanning against normal-appearing gastric mucosa.After the third round of positive screening,the peptide sequence AADNAKTKSFPV(AAD) appeared in 25%(12/48) of the analyzed phages.For the control peptide,these values were 6.8 ± 2.3,5.1 ± 1.7,3.5 ± 2.1,4.6 ± 1.9 and 1.1 ± 0.5,respectively.The values for AAD peptide were statistically signif icant(P < 0.01) for gastric cancer as compared with other histological classif ications and control peptide.CONCLUSION:A novel peptide is discovered to have a specific binding activity to gastric cancer,and can be used to distinguish neoplastic from normal gastric mucosa,demonstrating the potential for early cancer detection on endoscopy.

Tuberculous Otitis Media—A Rare Entity or a Missed Diagnosis

Objective: The aim of the study is to look for indicators of Tuberculous Otitis Media in all cases of chronic suppurative otitis media. Study Design: This is a retrospective study. Setting: This study was conducted in a tertiary care centre. Subjects and Methods: Detected cases of tuberculous otitis media (TBOM) cases studied retrospectively from January 2011 to December 2013 were included in the study. Investigations for tuberculosis were considered in the cases showing suspicious pale granulation tissue in the external auditory canal and middle ear and also in cases showing exuberant pale granulation tissue during mastoid surgery where Zeihl Nielson staining, histopathology, molecular genetic study was done. Cases showing positive result were included in the study. Results: During the study period 751 cases of CSOM were seen in outpatient room of which 18 cases of TBOM were diagnosed. Three patients were diagnosed preoperatively and 181 underwent surgery of which 15 cases were diagnosed positive, from the tissue obtained during the procedure. Direct smear was positive in four cases, concentration techniques in seven cases. Line probe assay was taken as diagnostic in all the cases. None of the cases were positive on histopathology. Conclusion: Tuberculous otitis media is often missed as the classical features are not seen in all cases of TBOM. The absence of these should not stop the clinician from diagnosing the disease. Suspicious tissue should therefore be tested properly to avoid missing the diagnosis and to prevent any complications.

Molecular authentication of the traditional Chinese medicine Tongren Dahuoluo Wan and its alternative formulation

Tongren Dahuoluo Wan has been a popular traditional Chinese medicine in international pharmaceutical markets for hundreds of years. Leopard bone powder is the key element in its formulation. However, the leopard has been listed for wildlife conservation, which limits the use of the leopard bone supplies. Therefore, an alternative formulation which substitutes leopard bone with zokor bone in the formula of Tongren Dahuoluo Wan is now manufactured. To develop a simple and reliable molecular method for authenticating the two patent medicines,mitochondrial nucleotide polymorphic sites of 12 S rRNA,COI and Cytb genes were screened in leopard and zokor bones, and nine pairs of species-specific primers were verified for discriminating the two species. For the patent medicine authentication, we set up a molecular diagnostic assay to resolve the difficulties of low concentration of target DNAs and presence of PCR-inhibitory substances in this complex medicine, and successfully confirmed leopard or zokor content using the nine pairs of species-specific primers. We recommend a common technical strategy for authentication of species origins in traditional Chinese medicine, and discuss the experimental solutions for technical problems of molecular diagnostic assays.