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DNA extraction from microdissected cells has become essential for handling clinical specimens with advances in molecular pathology. Conventional methods have limitations for extracting amplifiable DNA from specimens containing a small number of cells. We developed an ammonium sulfate DNA extraction method (A) and compared it with two other methods (B and C). DNA quality and quantity,β-globin amplification, and detectability of two cancer associated gene mutations were evaluated. Method A showed the best DNA yield, particularly when the cell number was very low. Amplification of theβ-globin gene using DNA from the SNU 790 cell line and papillary thyroid carcinoma (PTC) cells extracted with Method A demonstrated the strongest band.BRAFV600Emutation analysis using ethanol-fixed PTC cells from a patient demonstrated both a “T” peak increase and an adjacent “A” peak decrease when 25 and 50 cells were extracted, whereas mutant peaks were too low to be analyzed using the other two methods.EGFRmutation analysis using formalin-fixed paraffin-embedded lung cancer tissues demonstrated a mutant peak with Method A, whereas the mutant peak was undetectable with Methods B or C. Method A yielded the best DNA quantity and quality with outstanding efficiency, particularly when paucicellular specimens were used.

Follicular variant of papillary thyroid carcinoma (FVPTC), particularly the encapsulated subtype, often causes a diagnostic dilemma. We reconfirmed the molecular profiles in a large number of FVPTCs and investigated the efficacy of the preoperative mutational analysis in indeterminate thyroid nodules. BRAF V600E/K601E and RAS mutational analysis was performed on 187 FVPTCs. Of these, 132 (70.6%) had a point mutation in one of the BRAF V600E (n=57), BRAF K601E (n=11), or RAS (n=64) genes. All mutations were mutually exclusive. The most common RAS mutations were at NRAS codon 61. FNA aspirates from 564 indeterminate nodules were prospectively tested for BRAF and RAS mutation and the surgical outcome was correlated with the mutational status. Fifty-seven and 47 cases were positive for BRAF and RAS mutation, respectively. Twenty-seven RAS-positive patients underwent surgery and all except one patient had FVPTC. The PPV and accuracy of RAS mutational analysis for predicting FVPTC were 96% and 84%, respectively. BRAF or RAS mutations were present in more than two-thirds of FVPTCs and these were mutually exclusive. BRAF mutational analysis followed by N, H, and KRAS codon 61 mutational analysis in indeterminate thyroid nodules would streamline the management of patients with malignancies, mostly FVPTC.

Objectives. This study assessed the correlation between performance intelligence and the postoperative cochlear implant (CI) outcome in Korean-speaking children. In addition, the relationship between the performance intelligence subscales and the post-CI speech outcome was evaluated. Materials and Methods. Thirteen pediatric CI users (five males, eight females; median age at implantation 6.2 (range 1.3–14.2) years; median age at intelligence test 9.3 (range 5–16) years) who were tested using the Korean Educational Development Institute-Wechsler Intelligence Scale for children were studied. The correlations between the intelligence scores and 1-2 years postoperative Categories of Auditory Performance (CAP) scores and between subscales of performance and 1-2 years postoperative CAP scores were analyzed. Results. There was no correlation between the categories of verbal intelligence quotient (IQ) and performance IQ for “mentally retarded” and “average,” respectively (Spearman’s rho = 0.42, P=0.15). There was a strong correlation between performance IQ and the postoperative CAP scale (Spearman’s rho = 0.8977, P=0.0008). “Picture arrangement” and “picture completion,” reflecting social cognition, were strongly correlated with the postoperative CAP scales. Conclusion. Performance intelligence, especially social cognition, was strongly related to the postoperative CI outcome of cochlear implant users. Therefore, auditory rehabilitation, including social rehabilitation, should maximize the postoperative CI outcomes.