Diffuse sclerosing variant of papillary thyroid carcinoma: major genetic alterations and prognostic implications.

AIM: Diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is an uncommon variant of PTC, and its prognostic significance remains controversial. The aim of this study was to investigate the major genetic alterations of DSV-PTC and their prognostic implications. METHODS AND RESULTS: We included 37 patients with DSV-PTC who underwent thyroid surgery and had formalin-fixed paraffin-embedded samples. We tested for a panel of genetic alterations, including BRAF(V) (600E) , NRAS codon 61, HRAS codon 12/13/61 and KRAS codon 12/13 point mutations as well as RET/PTC1, RET/PTC3 and PAX8/PPARγ rearrangements using reverse transcription real-time polymerase chain reaction (PCR). All genetic alterations found on PCR were confirmed by Sanger sequencing. Associations between the identified genetic alterations and clinicopathological characteristics were evaluated. Among 37 cases of DSV-PTC, 17 were positive for RET/PTC1 (46%), six for RET/PTC3 (16%) and nine for BRAF(V) (600E) (24%). All mutations/rearrangements were mutually exclusive. The remaining five cases had none of the above genetic alterations. DSV-PTC with RET/PTC3 rearrangement was associated with advanced-stage disease, including T4 and distant metastasis (P < 0.05). Patients with RET/PTC3 showed a higher frequency of persistent disease (P < 0.01). In contrast, DSV-PTC with RET/PTC1 was associated with a higher prevalence of disease remission (P < 0.05) and coexistent Hashimoto's thyroiditis (P < 0.01). CONCLUSION: Taken together, RET/PTC rearrangement was the major genetic alteration seen in patients with DSV-PTC, and the RET/PTC3 rearrangement was associated with advanced stage at diagnosis and poor clinical outcome.

Changes in medical students' motivation and self-regulated learning: a preliminary study.

OBJECTIVE: To investigate whether medical students' motivation and Self-Regulated Learning (SRL) change over time to enhance our understanding of these constructs as dependent variables in medical education. METHODS: A cohort of first-year students (n=43) at a medical school in South Korea completed a self-report questionnaire on motivation and SRL--the Motivated Strategies for Learning Questionnaire (MSLQ). The same questionnaire was administered to the same cohort in the beginning of Year 2. A Wilcoxon signed-rank test was conducted to determine if changes in participants' MSLQ scores occurred between in Years 1 and 2. RESULTS: Forty-one students completed the questionnaires in both years (95% response rate). Participants' motivation scores significantly increased, whereas their SRL scores decreased significantly after they went through Year 1. The most notable change in participants' MLSQ scores was in the increase in their test anxiety. There was a positive association between the participants' test anxiety and their cognitive strategies use in Year 1, which changed to a negative one in Year 2. Meanwhile, participants' test anxiety scores and their self-regulation scores became more negatively associated over time. CONCLUSIONS: Our study shows that even as medical students become more motivated, they actually use fewer self-regulated strategies over time. Our findings highlight the need for change in the medical school's learning environment to lessen students' test anxiety to facilitate their use of cognitive and meta-cognitive strategies.