The abilities of self-study,thinking and communication are much more emphasized in the problem based learning(PBL)than in the conventional curriculum.From the view of the inherent relationship between the ability training and PBL,this paper probes into the characteristics of PBL to find the way of fitting the situation of our country.It is essential to the successful teaching and training more high quality students.

Objective To study the correlation between structure of b D -glucan derivatives from Poria cocos sclerotiuma and anti gastric cancer activities of elderly rats.Methods A water insoluble (1→3)-β-D-glucan (PCS3-Ⅱ ) isolated from fresh sclerotium of Poria cocos was sulfated,carboxymethylated,methylated,hydroxyethylated and hydroxypropylated,respectively,to prepare five water-soluble derivatives.Their activities of the native β-glucan and five derivatives against gastric cancer cell strains of MKN-45,SGC 7901and MKN-28 were tested in vitro and in vivo.Results The native β-glucan did not show any anti-gastric cancer activity,while the sulfated and carboxymethylated derivatives significantly exhibited the anti gastric cancer activity against MKN-45,SGC-7901 and MKN-28 cells in vitro,and elderly rats with MKN-45 transplanted tumor,especially.The gastric cancer inhibition rates of elderly rats were 32.7％ and 36.4％ for the 100 mg/kg sulfated and carboxymethylated derivatives,respectively.Conclusions The fresh sclerotium of Poria cocos polysaccharides can not show any anti gastric cancer activity in vitro,but the sulfated and carboxymethylated derivatives may increase the inhibition effect.Water-solubility,higher chain stiffness and relatively molecular weight would be benefit to increase anti-elderly gastric cancer activity of polysaccharides from Poria cocos sclerotiuma.

BACKGROUND: There are plenty of studies of estrogen effects on mammalian osteoblast, but the studies of estrogen effects on bird osteoblast cannot be found. There are many reports about the side effects of letrozole on bone metabolism, but there are no reports about the effect of letrozole on osteoblast.OBJECTIVE: The effects of estrogen and letrozole on the proliferation, cell cycle, estrogen receptor mRNA expression and alkaline phosphatase (ALP) activity of chicken osteoblast in vitro were studied in order to illustrate the mechanism of medullary bone osteogenesis.METHODS: The osteoblasts were harvested from the frontal bone of 15-day SPF chicken embryos by the enzyme digestion, and treated with various mass concentrations of estrogen (0, 5, 10, 20, 100. 200, 400,800, 2 000, 20 000 ng/L) and letrozole (0, 5.10, 25, 50, 100, 250, 500, 1 000, 5 000 μg/L). The proliferation rates of the osteoblast treated with estrogen or letrozole were measured through the MTT method, The ALP activities of osteoblast were measured by the pNPP method. The cell cycle was measured by flow cytometry. The expression of estrogen receptor mRNA was detected using real-time fluorescent quantitative polymerase chain reaction (PCR).RESULTS AND CONCLUSION: The estrogen could promote proliferation of osteoblast in concentration- and time-dependent fashion. Estrogen could increase the expression of estrogen receptor mRNA, impulse cell cycle, and elevate ALP activities.Letrozole could increase the cell population, impulse cell cycle, inhibit estrogen receptor mRNA expression, but letrozole has no effects on ALP synthesis and secretion.

AIM: To investigate the regulatory effects of lipopolysaccharide binding protein(LBP)on activation of p38 signaling pathway induced by lipopolysaccharide(LPS)in alveolar macrophages. METHODS: The LBP from actue phase rat serum was purified by ammonium sulphate precipitation, Bio-Rex70 resin and the MonoQ column. Rat alveolar macrophages were exposed to LPS (0 01 mg/L or 1 mg/L) the various concentrations of LBP(0 mg/L, 0 01 mg/L, 0 1 mg/L,1 mg/L and 10 mg/L) Western blotting were used to detect phospho-p38 in alveolar macrophages RESULTS: SDS-PAGE analysis indicated that the purified preparation of rat LBP showed homogeneity and the molecular weight was 60 kD.The binding of lipopolysaccharide to mononuclear cells were enhanced by purified rat LBP. Stimulation of rat alveolar macrophages with LPS at concentration of 0.01 mg/L was LBP dependent. LBP at concentrations up to 1 mg/L was able to increase the activation of p38. However , when LBP concentrations were further increased to 10 mg/L, the phosphorylation levers of p38 were lower as compared with that in the presence of 1 mg/L. Stimulation of rat alveolar macrophages with LPS at concentrations of 1 mg/L was LBP-independent. CONCLUSION: The activation of p38 induced by LPS at lower concentration(0.01 mg/L ) was LBP-dependent, meanwhile, LPS at higher concentration (1 mg/L ) was LBP-independent.

Objective:To investigate the expression of annexin 5 in rat testis after removing submandibular gland in rats. Methods:On day 14,28 and 42 after the operation,the changes of annexin 5 expression in rat testis were analyzed by Western blot and Immunohistochemistry.Results:Western blot showed that there was a 27.5% and a 35.2% significant increase(P

Objective To report a familial dentinogenesis imperfecta type Ⅱ (DGI type Ⅱ) with a novel splicing mutation in DSPP (dentin sialophosphoprotein) gene.Methods Based on the result of linkage analysis performed previously to map the candidate gene DSPP in the family, the promoter,the first four exons and exon-intron boundaries of DSPP were directly sequenced for the members of the DGI type Ⅱ family. Denaturing high performance liquid chromatography (DHPLC) analysis was performed to confirm the results of sequencing.Results A novel splicing mutation of 23 bp deletion in intron 2 of DSPP gene was identified by DNA sequence analysis. The mutation changed acceptor site sequence from CAG to AAG, and might result in functional abolition of possible branch point site in intron 2. DHPLC result was consistent with that of sequencing. The mutation may be identified in all affected individuals, but not found in normal members of the family and 50 controls.Conclusion These results suggest the deleted mutation of DSPP gene causes DGI type Ⅱ in the family. The mutation has not been reported before.

Background and purpose:Rabs are members of Ras-related small GTPase superfamily. Rab27A is a unique member in the Rab family and has specific implications in human genetic diseases. We studied the potential role of Rab27A in proliferation, distribution of cell cycle, apoptosis and invasion of breast cancer cells and its mechanism(s). Methods:The eukaryotic expression vector containing Rab27A open reading frame (ORF) pcDNA3.1(+) - Rab27A was constructed and transfected into MDA-MB-231 breast cancer cells. Then we detected the changes in terms of cell growth, cell cycle distribution, apoptosis and in vitro invasion capability before and after transfection. We also applied RT-PCR to investigate the molecular basis.Results:① The expression of Rab27A was increased as invasive and metastatic ability increased in four human breast cancer cell lines. ② Overexpression of Rab27A can promote breast cancer cells to grow faster, increase the proportion of S phase cells, avoid apoptosis and invade in vitro. ③ Rab27A transfectants constitutively enhanced the expression of Cyclin D1, MMP-7 and MMP-9 in MDA-MB-231 cell lines, on the contrary, that of p16 were down-regulated constitutively. Reduced Rab27A expression by RNAi down-regulated the expression of Cyclin D1, MMP-7 and MMP-9, and up-regulated p16 expression.Conclusions:Rab27A can stimulate breast cancer cells to proliferate, increase the proportion of cells in S phase,avoid apoptosis and invade in vitro by regulating the expression of Cyclin D1, MMP-7, MMP-9 and p16.

Objective:To explore the relationship between constitutional types of Chinese medicine and Alzheimer's disease (AD) and to construct an early warning model for AD risk.Methods:In the established multimodal interventions to delay dementia and disability in rural China (MIND-China) study, 4 033 elderly subjects aged ≥60 years old were included. The data including demographic, underlying disease and neuropsychological data were collected.The Chinese medicine service record form for the elderly was used to assess constitutional types of Chinese medicine and to apply the NIA-AA diagnostic criteria published by the National Institute on Aging and the Alzheimer's Association in 2011 for the diagnosis of clinically likely AD. Logistic regression analysis and AD risk prediction models were constructed using R statistical software, and the final prediction results were presented using columnar plots.Results:The MIND-China cohort was dominated by the abnormal constitution (69.28%), of which Phlegm-wetness type was the most common (58.05%), followed by Yang-deficiency type (23.85%). The most constitutional type of Chinese medicine among AD patients was Phlegm-wetness type (54.35%), followed by Qi-depression type (38.04%). Multi-factorial logistic regression analysis suggested that increasing age ( β=0.101, P<0.001, OR=1.107, 95% CI=1.069-1.146) and Qi-depression type ( β=0.622, P=0.016, OR=1.862, 95% CI=1.116-3.076) were able to increase the risk of developing AD, while education ( β=-1.047, P<0.001, OR=0.351, 95% CI=0.205-0.584) was able to reduce the risk of developing AD. By using the risk score model to calculate the total risk score for each subject and plotting the receiver operating characteristic curve (ROC), the area under the ROC was 0.769 and the calibration curve showed excellent consistency between prediction and reality. Conclusion:Older adults with Qi-depression type are significantly associated with an increased likelihood of AD.

OBJECTIVETo evaluate the role of germline mutations of TP53 gene among a Chinese population with high risk for breast cancer.

METHODSA total of 81 BRCA-negative breast cancer probands from cancer families were analyzed using targeted capture and next-generation sequencing. Candidate mutations were verified with Sanger sequencing. Co-segregation analyses were carried out to explore the likely pathogenicity of the mutation.

RESULTSOf the 81 BRCA-negative patients, 3 exonic mutations in the TP53 gene were identified in 3 breast cancer patients. Of these, 2 mutations were previously reported and 1 was novel. One family with TP53 mutation has met the criteria for Li-Fraumeni syndrome (LFS) and accounted for 9.1% of all families who fulfilled the diagnostic criteria for LFS. Two of the carriers were diagnosed with breast cancer under the age of 30, and have accounted for 11.8% (2/17) of all very young (≤30 years) breast cancer patients in our study.

CONCLUSIONThe TP53 germline mutation is more common in Chinese population with a high risk for breast cancer than previously thought. TP53 gene mutation screening should be considered particularly for patients with a family history of LFS and very young age of onset.

Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Breast Neoplasms ; ethnology ; genetics ; China ; DNA Mutational Analysis ; Exons ; Family Health ; Female ; Genetic Predisposition to Disease ; ethnology ; genetics ; Germ-Line Mutation ; Heterozygote ; Humans ; Li-Fraumeni Syndrome ; ethnology ; genetics ; Male ; Middle Aged ; Pedigree ; Risk Factors ; Tumor Suppressor Protein p53 ; genetics ; Young Adult

As a prescription for tonifying kidney yang， Youguiwan accords with the pathogenesis of osteoarthritis. Professor LIU Yuan-lu from the Affiliated Hospital of Liaoning University of Traditional Chinese Medicine found that modified Youguiwan had a significant effect on the clinical conservative treatment of osteoarthritis pain with Chinese medicine. There are teams studying the mechanism of Youguiwan in the treatment of osteoarthritis in China， but the profound study of the compound needs the mechanism of each component as support. Youguiwan contains 10 kinds of Chinese medicine， including Rehmanniae Radix Praeparata， Aconiti Lateralis Radix Praeparata， Cinnamomi Cortex， Dioscoreae Rhizoma， Corni Fructus， Cuscutae Semen， Angelicae Sinensis Radix， Eucommiae Cortex， Cervi Cornus Colla， and Lycii Fructus. With more and more attention to the study of Chinese medicine monomer， the amount of related research in this field is increasing. Therefore， it is of great significance to summarize the mechanism of Youguiwan in the treatment of osteoarthritis. Based on the sovereign， minister， assistant， and guide of Chinese medicine in Youguiwan， this paper used China National Knowledge Infrastructure （CNKI）， Pharmacopoeia of the People's Republic of China （2020 edition Vol. 1）， and ChemicalBook platform to understand the active components of each kind of Chinese medicine， and used PubMed to search. The latest research progress of effective monomers that had an intersection with the mechanism of osteoarthritis was summarized， and there were five pharmacological effects including anti-inflammation， pain inhibition， chondrocyte apoptosis， oxidative stress， and extracellular matrix degradation， involving several signaling pathways. The theory of sovereign， minister， assistant， and guide and the molecular mechanism were integrated and discussed， respectively， and finally， they were combined with traditional Chinese medicine theory， providing theoretical references for further study in this direction.