Biomedical subjects

Tsan-Chi Chen

Publications and source records attributed to Tsan-Chi Chen.

4 recordsLinked to original sources

PubMed2006

Combining multiplex reverse transcription-PCR and a diagnostic microarray to detect and differentiate enterovirus 71 and coxsackievirus A16.

Cluster A enteroviruses, including enterovirus 71 (EV71) and coxsackievirus A16 (CA16), are known to cause hand-foot-and-mouth disease (HFMD). Despite the close genetic relationship between these two viruses, EV71 is generally known to be a more perpetuating pathogen involved in severe clinical manifestations and deaths. While the serotyping of enteroviruses is mostly done by conventional immunological methods, many clinical isolates remain unclassifiable due to the limited number of antibodies against enterovirus surface proteins. Array-based assays are able to detect several serotypes with high accuracy. We combined an enterovirus microarray with multiplex reverse transcription-PCR to try to develop a method of sensitively and accurately detecting and differentiating EV71 and CA16. In an effort to design serotype-specific probes for detection of the virus, we first did an elaborate bioinformatic analysis of the sequence database derived from different enterovirus serotypes. We then constructed a microarray using 60-mer degenerate oligonucleotide probes covalently bound to array slides. Using this enterovirus microarray to study 144 clinical specimens from patients infected with HFMD or suspected to have HFMD, we found that it had a diagnostic accuracy of 92.0% for EV71 and 95.8% for CA16. Diagnostic accuracy for other enteroviruses (non-EV71 or -CA16) was 92.0%. All specimens were analyzed in parallel by real-time PCR and subsequently confirmed by neutralization tests. This highly sensitive array-based assay may become a useful alternative in clinical diagnostics of EV71 and CA16.

DNA Probes↗

PubMed2005

Distinct translation regulation by two alternative 5'UTRs of a stress-responsive protein--dPrx I.

Translation efficiency is often regulated in part by 5'-untranslated region (5'UTR). Sequence analysis of an evolutionarily conserved stress-responsive protein, Drosophila Peroxiredoxin I (dPrx I), found the transcript to have two alternative 5'UTRs that lead to an identical coding sequence: namely Ia and Ib. Although both isoforms coexisted in Drosophila cells, the Ia isoform appeared to be dominant. Furthermore, reporter assay found that Ia enhanced translation in steady-state cells while Ib increased translation in cells under oxidative stress. Together, our data suggest that the two alternative 5'UTRs of dPrx I may be involved in a translational regulatory mechanism that responds to cellular oxidative stress.

5' Untranslated Regions↗

PubMed2004

Coupling multiplex RT-PCR to a gene chip assay for sensitive and semiquantitative detection of severe acute respiratory syndrome-coronavirus.

An early and accurate diagnostic assay for severe acute respiratory syndrome (SARS) is crucial for infection control. However, most of the diagnostic methods available today, such as real-time reverse transcriptase-polymerase chain reaction (RT-PCR), require a second detection method for confirmation because they detect a single sequence region of the SARS-coronavirus (SARS-CoV). For sensitive and accurate early diagnosis, we report a novel assay system combining multiplex RT-PCR and a diagnostic gene chip to detect multiple virus-specific genomic sequences of SARS-CoV. With 53 clinical specimens, we successfully demonstrate that this technique offers not only a high-accuracy diagnosis for early SARS infection but also a semiquantitative assay.

DNA Primers↗

PubMed2003

Sensitive and quantitative detection of severe acute respiratory syndrome coronavirus infection by real-time nested polymerase chain reaction.

A quantitative, real-time, nested polymerase chain reaction (PCR) method, combining the high sensitivity of nested PCR with time-saving real-time instrumentation, was developed for large-scale screening for severe acute coronavirus (SARS) coronavirus. Forty-six clinical specimens were analyzed by this method, and results were compared with those obtained by conventional, single-round, real-time reverse-transcriptase PCR (RT-PCR) performed in parallel. Of the 17 positive results, 2 identified by our method were not detected by single-round, real-time RT-PCR, which suggests that real-time nested PCR has the potential for increased sensitivity, leading to earlier detection of SARS.

DNA, Viral↗