Rapid detection of Candida albicans in oral exfoliative cytology samples by loop-mediated isothermal amplification.

Loop-mediated isothermal amplification (LAMP) rapidly amplifies DNA under isothermal conditions. The aim of this study was to detect Candida albicans and compare the positivity rate in the LAMP reaction with that of conventional methods for oral exfoliative cytology (EC) samples. Sixty-eight EC samples from 53 patients were subjected to LAMP analysis. These patients had been clinically diagnosed with leukoplakia, squamous cell carcinoma, oral lichen planus (OLP), stomatitis, oral candidiasis, and other malignancies. LAMP reactions were defined as positive when the sample turbidity exceeded 0.1 (arbitrary unit). Periodic acid-Schiff (PAS) staining and microbial culture were also performed to detect Candida species in EC samples. The LAMP reaction detected C. albicans in 42.6% of EC samples. Candida species were detected in 32.4% of the same samples by culturing and in 29.4% of samples by PAS staining. C. albicans DNA was detected most frequently in samples from OLP patients. We conclude that, in comparison to conventional methods for detection of C. albicans, the LAMP method is highly sensitive and time-saving, and does not require expensive equipment or diagnostic technology. It may therefore be useful for on-site screening of C. albicans at dental clinics.

Rapid and Specific Screening Assay for KRAS Oncogene Mutation by a Novel Gene Amplification Method.

BACKGROUND: Epidermal growth factor receptor (EGFR) is a target of molecular therapeutics for colorectal cancer. However, mutation of Kirsten rat sarcoma viral oncogene homolog (KRAS) gene at codons 12 and 13 attenuates the therapeutic effect of anti-EGFR therapies. Therefore, the detection of KRAS gene mutation is important for therapeutic decision-making. MATERIALS AND METHODS: KRAS gene mutation at codons 12 (c.34G>T, c.35G>C, c.35G>A) and 13 (c.38G>A) in six cancer cell lines were investigated. A loop-mediated isothermal amplification-based procedure was developed that employed peptide nucleic acid to suppress amplification of the wild-type allele. RESULTS: This mutation-oriented gene-amplification procedure can amplify the DNA fragment of the KRAS gene with codon 12 and codon 13 mutation within 30 min. Moreover, boiled cells can work as template resources. CONCLUSION: This newly developed procedure can be useful for patient stratification for anti-EGFR therapies.