Problem-based learning (PBL) is a unique form of pedagogy dedicated to developing students' self-learning and clinical practice skills. After several decades of development, although applications vary, PBL has been recognized all over the world and implemented by many medical schools. This review summarizes and updates the application and study of PBL in medical education through the literature published between 1993 and early 2017. It focuses on understanding real medical PBL courses and ways to improve PBL to achieve better learning outcomes. PBL aims to develop lifelong skills to solve practical problems rather than limiting learning to theoretical knowledge. To achieve this goal, strict and reasonable procedures need to be designed and implemented. Rigorous monitoring and timely feedback and evaluation are indispensable to constant improvements and perfecting of the process. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(2):186-194, 2018.

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ZCCHC9 is a type of CCHC type zinc-finger containing protein which was found to be expressed in some tissues including brain and testicles in mice. Expression and function of ZCCHC9 in human tissues including cancer was largely unknown. In this study, we investigated the expression and function of ZCCHC9 in human non-small cell lung cancer (NSCLC) and the related molecular mechanism. Immunochemistrical standing showed that ZCCHC9 was mainly located in the nucleus in bronchial epithelial cells and epithelial cells of submucosal glands (58.3% [14/24]). But in NSCLC cells ZCCHC9 was mainly located in the cytoplasm and the positive rate was 54.5% (60/110). Ectopic cytoplasmic expression of ZCCHC9 in cancer tissues was significantly associated with advanced TNM stages (III+IV), lymph node metastasis, and poor clinical outcome (P < 0.05). Overexpression of cytoplasmic ZCCHC9 using transfection of ZCCHC9 cDNA in A549 and NCI-H1299 cells significantly upregulated the proliferation and invasion of these cancer cells in vitro (P < 0.05). Western blot study showed that overexpression of cytoplasmic ZCCHC9 significantly upregulated expression of p-JNK, Cyclin D1, and MMP7 (P < 0.05). Next we used the inhibitor of JNK pathway to inhibit the activity of the JNK pathway and the results showed that co-addition of SP600125 significantly abolished the function of ZCCHC9 to promote the proliferation and invasion of cancer cells. These results indicate that cytoplasmic ZCCHC9 could promote the proliferation and invasion of NSCLC through the JNK pathway and may be a promising cancer maker. K E Y W O R D S JNK, lung cancer, NSCLC, ZCCHC9

Background Homocysteine (Hcy) is considered to be a risk factor for cardiovascular and cerebrovascular diseases. Few studies have evaluated the distribution of Hcy on a large-scale health examination. Accordingly, this study aimed to investigate the level and distribution of Hcy in the population with healthy physical examination and the correlation with other biomarkers, and analyzed for cardiovascular and other diseases. Methods Measurements of serum Hcy, TC, TG, LDL-c, HDL-c, ALT, ALP, γ-GT, TBIL, GLU, urea, Cr, UA, and related metabolic risk factors were selected for analysis from 8063 medical examination samples collected from February 2017 to April 2020. The relationship between Hcy and other biochemical indicators were evaluated with the multivariate regression model of age, gender, smoking, drinking, body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP). Results Among 8063 cases, the age, BMI, SBP, and DBP of the high-Hcy group were higher than those of the low-Hcy group, the difference was statistically significant (P < 0.001), and the proportion of males, smoking, and drinking were higher than the low-Hcy group, the difference was statistically significant (P < 0.001); Hcy of the abnormal GLU group is higher than the normal GLU group (P = 0.002) and the Hcy of abnormal TG and HDL is higher than that of the normal blood lipid group (P < 0.001); Hcy of people with abnormal UA and Urea was higher than that of people with normal renal function (P < 0.001, P = 0.007). In multivariate analysis, lnHDL-C was negatively correlated with lnHcy (β = − 0.038, SE = 0.016, P = 0.019), lnCr was positively correlated with lnHcy (β = 0.055, SE = 0.016, P < 0.001), lnUA and lnHcy were positive correlated (β = 0.043, SE = 0.019, P = 0.022). Conclusion Hcy is closely related to HDL-c, Cr, and UA, which indicates that Hcy may affect the metabolism of HDL-c and UA, and can also be used as an auxiliary diagnostic index for kidney injury.

Hes3 is a basic helix-loop-helix factor gene, which was found to be involved in neural cell differentiation. Expression and clinicopathological significance of Hes3 in non-small cell lung cancer was not clear. In this study, we used immunohistochemistry to examine Hes3 expression in normal human lung and non-small cell lung cancer tissues. Hes3 expression was detected in cytoplasm and nucleus. Hes3 expression in bronchial epithelial cells and epithelial cells of submucosal glands was relatively weak and the positive rate was of 30.3% (10/33). Hes3 expression in non-small cell lung cancer tissues (51.8% (58/112)) was significantly higher than that in normal lung tissues (p < 0.05). Hes3 expression in cancer tissues was significantly associated with poor differentiation, advanced TNM stages, lymph node metastasis, and a shorter patient survival time (p < 0.05). In vitro study showed that overexpression of Hes3 in A549 cells significantly promoted cancer cell proliferation and invasion, while inhibition of Hes3 expression significantly downregulated cancer cell proliferation and invasion (p < 0.05). Western blotting showed that overexpression of Hes3 significantly upregulated expression of Cyclin D1, Cyclin D3, and MMP7 in A549 cells, while inhibition of Hes3 expression in LK2 cells significantly downregulated the expression of these molecules (p < 0.05). These results indicated that Hes3 may contribute to the malignant phenotype of non-small cell lung cancer, possibly through regulation of Cyclin D1, Cyclin D3, and MMP7, and may be a promising cancer marker.