1.Practice and reflection of the case teaching in science of health policy
Guangfeng DUAN ; Lijie WANG ; Wenhua TIAN
Chinese Journal of Medical Education Research 2014;(9):899-901,902
This article analyzed the importance of implementing case teaching in health policy course based on its characteristics, and introduced the design and the process of case teaching, from the general idea, teaching content, implementation process and evaluation method. Some problems which should be paid attention to and the relevant suggestions were brought out according to the teaching practice.
2.Studies on the mechanism of Syk and JNK in the heart tissue of type 1 diabetic rats
Yufeng CHEN ; Guangfeng LONG ; Xixi TIAN ; Yingchun QIAO ; Shengyu LI ; Meiting XUE ; Yunde LIU ; Yujie CUI ; Yanna SHEN
Tianjin Medical Journal 2017;45(5):463-467
Objective To investigate the expressions of spleen tyrosine kinase (Syk), c-Jun amino terminal kinase (JNK) and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in the heart tissue in SD rat model of diabetic cardiomyopathy, and to explore the relationship between Syk, JNK and NLRP3. Methods Clean male SD rats were randomly divided into the control (Ctrl) group and diabetic cardiomyopathy model (DCM) group. Rats of DCM group were treated with a single intraperitoneal injection of streptozotocin (STZ), while rats of Ctrl group were injected with the same dose of citrate buffer. The random blood glucose level and body weight were monitored every week until 20 weeks after STZ or citrate buffer injection, then all the rats were killed and their hearts were obtained. Rat H 9c2 cardiomyocytes were randomly divided into normal glucose treatment (NG) group, high glucose treatment (HG) group, Syk inhibitor control (BAY) group and Syk inhibitor high glucose (HG+BAY) group. The Syk and JNK phosphorylations and NLRP3 protein expression were detected by Western blot assay in the heart tissue of SD rats and H9c2 cardiomyocytes. The NLRP3, cysteine-containing aspartate specific protease 1(caspase-1) and interleukin (IL)-1β expressions at mRNA level were detected by reverse transcription-polymerase chain reaction (RT-PCR). Results The random blood glucose level was significantly increased (P<0.05) and the body weight was significantly decreased (P<0.05) in DCM group compared with those of Ctrl group. The expressions of cardiac p-Syk, p-JNK and NLRP3 at protein level were significantly increased in DCM group compared with those of Ctrl group (P<0.05). Furthermore, the mRNA levels of NLRP3, caspase-1 and IL-1β were significantly up-regulated (P < 0.05). BAY treatment significantly inhibited the high glucose-induced NLRP3, caspase-1 and IL-1β mRNA expressions and p-JNK, NLRP3 protein expressions in H9c2 cardiomyocytes (P < 0.05). Conclusion JNK phosphorylation and NLRP3 inflammasome activation induced by Syk play an important role in the pathogenesis of diabetic cardiomyopathy.
3.Low shear stress induces human vascular endothelial cell apoptosis by activating Akt signal and increasing reactive oxygen species.
Junxia ZHANG ; Zhimei WANG ; Guangfeng ZUO ; Bing LI ; Junjie ZHANG ; Nailiang TIAN ; Shaoliang CHEN
Journal of Southern Medical University 2013;33(3):313-317
OBJECTIVETo investigate the effect of low shear stress (LSS) on apoptosis of human vascular endothelial cells (ECs) and explore the possible mechanisms.
METHODSParallel flow chamber was used to apply LSS at 2 dyne/cm(2) on EA.hy926 cells derived from human umbilical vein endothelial cells for 120 min. Cell apoptosis following LSS was verified by morphological observation, DAPI staining and TUNEL test. The level of intracellular reactive oxygen species (ROS) was measured by dihydroethidium (DHE) and mitoSOX. Western blotting was performed to detect the activity of Akt in the cells.
RESULTSEC detachment and apoptosis were observed after exposure to 2 dyne/cm(2) LSS for 120 min. Time course study showed that the phosphorylation level of Akt on residues Ser473 and Thr308 was elevated after flow initiation. Exposure to LSS at 2 dyne/cm(2) for 120 min resulted in increased ROS production in the ECs at both the mitochondrial and cytoplasmic levels.
CONCLUSIONAkt activation and increased ROS levels are involved in LSS-induced EC apoptosis.
Apoptosis ; Cells, Cultured ; Endothelial Cells ; metabolism ; Endothelium, Vascular ; cytology ; Humans ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Reactive Oxygen Species ; metabolism ; Signal Transduction ; Stress, Mechanical
4.Antibacterial properties of silver nanoparticle-coated stainless steel prepared via active screen plasma surface modification in vitro
Zhaofei WANG ; Guoyun HE ; Fangcan TIAN ; Guangfeng LI ; Zhonghua CAO ; Xiangfei LIU
Chinese Journal of Tissue Engineering Research 2024;28(22):3464-3471
BACKGROUND:Most of the silver coating materials prepared using active screen plasma technology in the past do not involve the nanotechnology field.The formed silver coating is in a"thin film"form,which is coated on the surface of the substrate,and the distribution of silver particles on the surface is uneven.Its long-term antibacterial ability is challenged. OBJECTIVE:To prepare nano silver coatings capable of being"buried"within stainless steel(SS)substrates using active screen plasma surface modification(ASPSM)and to observe antibacterial activity. METHODS:The nano-silver coating was prepared by ASPSM technique on stainless steel substrate.Three groups of coating samples were prepared by adjusting the bombardment time(1,2,and 4 hours),which were denoted as 1 h-Ag-ASPSM@SS,2 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,respectively.The antibacterial activity of the coatings was analyzed by antibacterial ring test and Gram staining.The antibiotic coating samples of gentamicin combined with vancomycin were prepared by using stainless steel as substrate and were recorded as ACNs.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were inserted into Staphylococcus aureus or Pseudomonas aeruginosa suspension,respectively.The long-acting(84 days)antibacterial activity of the samples was analyzed by coating plate method.Bone marrow mesenchymal stem cells were co-cultured with stainless steel,2 h-Ag-ASPSM@SS,and ACNs,respectively.CCK-8 assay,dead/alive staining,and lactate dehydrogenase activity of cell supernatant were detected.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were taken after continuous exposure to Staphylococcus aureus suspension for 12 weeks.The amount of residual viable bacteria on the surface of the material was evaluated by spread plate method.Vancomycin drug sensitive disk method was used to evaluate the resistance of residual live bacteria on the surface of materials. RESULTS AND CONCLUSION:(1)With increasing bombardment time,the diameter of nano silver on the sample surface and the silver content in the coating gradually increased.Among them,the 2 h-Ag-ASPSM@SS exhibited the highest surface silver content while forming uniformly spherical nanoparticles.(2)Antibacterial ring test and Gram staining results demonstrated that compared with 1 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,the 2 h-Ag-ASPSM@SS exhibited better inhibitory effect on Staphylococcus aureus and pseudomonas aeruginosa.After co-culturing with bacteria for 42 and 84 days,the number of viable bacteria on the spread plate method was significantly lower in the 2 h-Ag-ASPSM@SS group compared to the stainless steel and ACNs groups.After co-culturing with Staphylococcus aureus for 84 days and Pseudomonas aeruginosa for 42 days,the number of viable bacteria on the surface of the eluate from the ACNs group was higher than that of the stainless steel group.(3)CCK-8 assay,live/dead staining and lactate dehydrogenase activity of cell supernatant displayed that 2 h-Ag-ASPSM@SS did not have obvious cytotoxicity.ACNs showed obvious cytotoxicity.(4)After co-culture with Staphylococcus aureus for 12 weeks,the residual viable bacteria on the surface of 2 h-Ag-ASPSM@SS group was less than that of stainless steel group,and the residual viable bacteria on the surface of the ACNs group was more than that of stainless steel group.Compared with the stainless steel group,the sensitivity to vancomycin was significantly decreased in the ACNs group(P<0.001),and there was no significant change in sensitivity to vancomycin in 2 h-Ag-ASPSM@SS group(P>0.05).(5)The above results indicate that the silver nanoparticle coated stainless steel greatly improves the deposition efficiency of silver nanoparticles on the stainless steel surface and has long-lasting antibacterial properties and good cell compatibility.
5.Research progress on genetic and epigenetic mechanisms in congenital heart disease.
Guangfeng TIAN ; Hui GAO ; Shasha HU ; Qiang SHU
Journal of Zhejiang University. Medical sciences 2018;47(3):227-238
Congenital heart disease (CHD) is a type of birth defects due to the abnormal development of heart and blood vessels during embryonic stage. Studies indicate that the etiology of CHD is complicated. Genetic and epigenetic mechanisms including chromosomal abnormalities, gene mutations, nucleic acid modifications, non-coding RNAs may play important roles in CHD. At present, genetic mechanisms such as chromosome abnormality and gene mutation have been widely used in the diagnosis and treatment of clinical diseases. However, the application of genetic and epigenetic modification in diagnosis and treatment of CHD still need further research. This paper reviews the relationship between chromosomal abnormality, gene mutation, copy number variation, epigenetic modification and the occurrence of CHD, which may provide a basis for further exploring the early diagnosis and individualized therapy of CHD.