OBJECTIVETo understand the molecular mechanism and find out the responsible genes for liver cancer by exploring the regulation of gene expression during hepatocarcinogenesis in tree shrew induced by aflatoxin B1 (AFB1).

METHODSThe tissues from tree shrew of different stages during the pathogenesis and development of hepatocellular carcinoma (HCC), liver cancer tissue, para-cancerous tissues, pre-cancerous liver tissues, liver tissues of the same stage from normal controls and the liver tissues taken before AFB1-treatment were analyzed for gene expression by cDNA array.

RESULTSFour patterns of gene expression were observed during AFB1-induced hepatocarcinogenesis. They were: genes up-regulated in HCC tissue and para-cancerous tissue, especially in HCC tissues; genes with similar expressing level in both HCC tissue and para-cancerous tissue, but higher than that in pre-cancerous tissue; genes down-regulated in HCC tissue; genes up-regulated before HCC appeared but down-regulated after HCC appeared.

CONCLUSIONDynamic observation of gene expression will be beneficial to elucidate the mechanisms of AFB1- induced hepatocarcinogenesis and locate the responsible genes.

Aflatoxin B1 ; toxicity ; Animals ; Gene Expression Profiling ; Liver Neoplasms, Experimental ; chemically induced ; genetics ; Oligonucleotide Array Sequence Analysis ; methods ; Tupaiidae

OBJECTIVES: In the previous studies, it has been suggested that temperament and character may affect specialty choice in medical students. The aim of this study is to investigate the effects of temperament and character on specialty interests in medical students. METHODS: A total 132 third-year medical students initially participated in this study. Among these participants, 128 students had filled out both demographic and Temperament and Character Inventory (TCI) questionnaires. Socio-demographic data, specialty interests and Cloninger's TCI scores were obtained. The specialty interests were categorized into surgical, medical and other departments. RESULTS: Among 128 students, 88 (68.7%), 29 (22.7%) and 22 (8.6%) students chose medical, surgical and other departments, respectively. Students choosing surgery departments showed lower Harm Avoidance scores (F = 4.39, df = 1, p = 0.04) and higher Self-Directedness scores (F = 4.30, df = 1, p = 0.04) than those who chose medical departments. There was no significant differences in Novelty Seeking, Reward dependence, Persistence, Cooperativeness, Self-Transcendence scores between groups. CONCLUSIONS: To the best of our knowledge, this is the first study that has demonstrated the relationship between TCI scores and specialty interests of medical students in Korea. The current study suggests that temperament and character influence specialty interests in medical students. These findings could have implications for medical education research and career counseling.
Education, Medical ; Humans ; Korea ; Reward ; Specialties, Surgical ; Students, Medical ; Temperament ; Vocational Guidance

PURPOSE: Although follicular thyroid cancer (FTC) has a relatively fair prognosis, distant metastasis sometimes results in poor prognosis and survival. There is little understanding of the mechanisms contributing to the aggressiveness potential of thyroid cancer. We showed that hypoxia inducible factor-1alpha (HIF-1alpha) induced aggressiveness in FTC cells and identified the underlying mechanism of the HIF-1alpha-induced invasive characteristics. MATERIALS AND METHODS: Cells were cultured under controlled hypoxic environments (1% O2) or normoxic conditions. The effect of hypoxia on HIF-1alpha, and epithelial-to-mesenchymal transition (EMT) related markers were evaluated by quantitative real-time PCR, Western blot analysis and immunocytochemistry. Invasion and wound healing assay were conducted to identify functional character of EMT. The involvement of HIF-1alpha and Twist in EMT were studied using gene overexpression or silencing. After orthotopic nude mouse model was established using the cells transfected with lentiviral shHIF-1alpha, tissue analysis was done. RESULTS: Hypoxia induces HIF-1alpha expression and EMT, including typical morphologic changes, cadherin shift, and increased vimentin expression. We showed that overexpression of HIF-1alpha via transfection resulted in the aforementioned changes without hypoxia, and repression of HIF-1alpha with RNA interference suppressed hypoxia-induced HIF-1alpha and EMT. Furthermore, we also observed that Twist expression was regulated by HIF-1alpha. These were confirmed in the orthotopic FTC model. CONCLUSION: Hypoxia induced HIF-1alpha, which in turn induced EMT, resulting in the increased capacity for invasion and migration of cells via regulation of the Twist signal pathway in FTC cells. These findings provide insight into a possible therapeutic strategy to prevent invasive and metastatic FTC.
Adenocarcinoma, Follicular/*genetics/metabolism ; Animals ; Anoxia/*genetics ; Cadherins/genetics ; Epithelial-Mesenchymal Transition/*genetics ; Gene Expression Regulation, Neoplastic ; Hypoxia-Inducible Factor 1, alpha Subunit/*genetics/metabolism ; Lymphokines ; Mice ; Neoplasm Invasiveness ; Phenotype ; Real-Time Polymerase Chain Reaction ; Signal Transduction/drug effects ; Thyroid Neoplasms/*genetics/metabolism ; Transcriptional Activation ; Twist Transcription Factor/*genetics/metabolism ; Vimentin/metabolism

OBJECTIVES: The combination extract of four kinds of herbs, Gastrodia elata, Liriope platyphylla, Dimocarpus longan, and Salvia miltiorrhiza, has shown to have memory improving effects in mice. The aim of this study was to investigate the efficacy and safety of the herbal mixture for improving working memory as well as microstructural changes in white matter integrity in individuals with subjective memory complaints. METHODS: Seventy-five individuals with subjective memory complaints were assigned to receive either placebo (n = 15) or herbal mixture (low-dose group, n = 30 and high-dose group, n = 30) supplementation in an 8-week, randomized, double-blind, placebo-controlled clinical trial. Changes in working memory performance and fractional anisotropy (FA) values reflecting white matter integrity from baseline to 8-week endpoint were assessed. RESULTS: The herbal mixture group showed an increase in working memory performance compared to the placebo group (p for interaction = 0.001). In addition, the herbal mixture group showed an increase in FA values in the temporo-parietal regions (corrected p < 0.05), which are crucially involved in working memory function and are among the most affected regions in patients with cognitive impairments. CONCLUSIONS: Findings from this study indicate that the herbal mixture may be a promising therapeutic option for individuals with subjective memory complaints.
Animals ; Anisotropy ; Diffusion Tensor Imaging ; Gastrodia ; Humans ; Memory* ; Memory, Short-Term* ; Mice ; Salvia miltiorrhiza

It is reported that depression has caused heavy disease burden across the world, with an possible association between ambient air pollution and depressive symptoms. In this paper, we reviewed relative literature in this field and summarized the research events on association between ambient air pollution and depression, both in China and abroad and found that the results of the existed studies were inconsistent, with most studies showing that there existed a positive correlation between the exposure of air pollution and depression, but few studies showing the negative correlation or no correlation between the two.
Air Pollutants/analysis* ; Air Pollution/statistics & numerical data* ; China ; Depression/epidemiology* ; Depressive Disorder ; Environmental Exposure/statistics & numerical data* ; Female ; Humans ; Particulate Matter/analysis* ; Research/trends* ; Residence Characteristics