Microbiology experiment existing independently from microbiology theoretical curriculum is an indispensable compulsory course in contemporary life science. This article presents the principle applied by the National Excellent Microbiology Course teaching group in Nankai University, which is to strengthen the undergraduates’ basic skills of conducting microbiology experiments. With an aim to enhance the core competitiveness of the undergraduates, we have established the three-level experimental contents. A new multilevel teaching pattern focusing on basic skill training as the cornerstone has been applied to enhance the overall competences of the students and to stimulate their innovation abilities. Students’ experimental accomplishment will also be taken into consideration when their experiment results are evaluated, which helps to standardizing their research ethics.

OBJECTIVETo construct plasmid expressing pacemaker gene pIRES2-EGFP-HCN2 and study its effects in transfected atrial myocytes in vitro and in canine model of sick sinus syndrome (SSS).

METHODSmHCN2 gene was isolated from PTR plasmids and cloned into eukaryotic expression plasmid pIRES2-EGFP. Recombinant plasmids pIRES2-EGFP-HCN2 was transfected with by electroporation into neonatal atrial cardiomyocytes or injected to the sinoatrial (SA) region of canines with SSS induced by catheter and chemical ablation. pIRES2-EGFP-HCN2 expression was detected under fluorescence microscope and confirmed by reverse transcription-polymerase chain reaction (RT-PCR). Spontaneous beating rate in atrial cardiomyocytes was detected with light microscope.

RESULTSEGFP expression was seen in transfected atrial cardiomyocytes 24 to 48 hours after transfection and the spontaneous beating rate was significantly increased than that in non-transfected atrial cardiomyocytes [(180 +/- 11) bpm vs (140 +/- 14) bpm, P < 0.05]. Heart rate was significantly increased 24 hours post recombinant plasmids pIRES2-EGFP-HCN2 injection compared to saline injection in canines with SSS [(150 +/- 13) bpm vs (105 +/- 17) bpm, P < 0.05]. Green fluorescence was also detected in frozen SA tissue sections of canines injected with recombinant plasmids pIRES2-EGFP-HCN2 and the production amplified by RT-PCR was about 300 bp which is consistent with mHCN2 gene fragment.

CONCLUSIONThe recombinant eukaryotic expression plasmid pIRES2-EGFP-HCN2 can improve pacing function in atrial myocytes and in canine model of SSS.

Animals ; Disease Models, Animal ; Dogs ; Gene Expression ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels ; In Vitro Techniques ; Ion Channels ; genetics ; Myocytes, Cardiac ; metabolism ; Plasmids ; Sick Sinus Syndrome ; therapy

The purpose of this study is to investigate the activity and mechanism of a new anti-tumor agent T03. MTT and colony formation assay were performed to determine anti-proliferation activity of T03 in vitro. Antitumor activity was observed by Renca xenograft model in vivo. The effect of T03 on cell cycle and apoptosis were measured by FCM analysis. Western blotting was performed to investigate the expression level of proteins in HepG2 cell lines treated with T03. T03 had anti-tumor activity by inhibiting tumor cell growth and colony formation in vitro, especially on hepatocellular carcinoma cells (HCC). At the concentration of 10 micromol x L(-1), T03 induced cell apoptosis and cell cycle arrest in HCC. Moreover, it proved that T03 reduced the tumor weight with the rate of 42.30% without any obviously side effect in Renca xenograft model. At the concentration of 2.0 micromol x L(-1), T03 was able to reduce the level of p-c-Raf (Ser259), and thus blocked Raf/MEK/ERK and AKT signaling in HepG2 cell lines. The result suggested that T03 has the potential to inhibit cell proliferation and induce cell apoptosis both in vitro and in vivo, particularly active against HCC, indicating T03 and its analogues may serve as a new anti-cancer drug against hepatocellular carcinoma.
Animals ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Cycle Checkpoints ; drug effects ; Cell Proliferation ; drug effects ; Hep G2 Cells ; drug effects ; Humans ; Liver Neoplasms ; pathology ; Signal Transduction ; drug effects ; Xenograft Model Antitumor Assays

Garcinia mangostana L. is a common tropical plant,which is also called mangosteen. Its exocarp is used as a tradi?tional medicine in India,Thailand,Myammar and other Southeast Asian countries. In recent years,systematic studies on the chemi?cal constituents of the plant have shown that G. mangostana contains various xanthone compounds in a large amount. Many studies have shown that these compounds display many pharmacological activities,such as antioxidant,antiproliferative,pro-apoptosis,anti-inflammation and antibacterial activities,which has attracted great attention in the medical community. This paper reviews the main chemical constituents of G. mangostana and their pharmacological effects.

ObjectiveTo investigate the effect of amitriptyline on lipid deposition and biochemical metabolism in a cell model of nonalcoholic fatty liver disease (NAFLD) by regulating the acid sphingomyelinase (ASM)/ceramide (CE) pathway. MethodsHepG2 and L02 cells were cultured in vitro to establish a cell model of NAFLD. MTT colorimetry was used to measure cell proliferation rate, and oil red O staining was used to observe the change of lipid droplets in cells. In the experiment, the cells were divided into normal control group, model group, Ami group, TNFα group, and Ami+TNFα group. An automatic biochemical analyzer was used to measure the levels of triglyceride (TG) and total cholesterol (TC) in cells and the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in supernatant; ELISA was used to measure the levels of CE and ASM in cells; Western blot was used to measure the protein expression ASM in cells, and RT-PCR was used to measure the mRNA expression of ASM in cells. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the Turkey test was used for further comparison between two groups. ResultsCompared with the normal control group, the NAFLD model group had significant increases in the protein and mRNA expression of ASM and the levels of CE, TG, TC, ALT, and AST (all P＜0.05). Compared with the model group, the Ami group had significant reductions in the protein and mRNA expression of ASM and the levels of CE, TG, TC, ALT, and AST (all P＜0.05), and the TNFα group had significant increases in the protein and mRNA expression of ASM and the levels of CE, TG, ALT, and AST (all P＜0.05). Compared with the TNFα group, the Ami+TNFα group had significant reductions in the protein and mRNA expression of ASM and the levels of CE, TG, TC, ALT, and AST (all P＜0.05). ConclusionThe ASM/CE pathway promotes lipid accumulation and may lead to hepatocyte steatosis, and amitriptyline can alleviate lipid deposition in NAFLD hepatocytes by inhibiting the ASM/CE pathway.

Objective To explore the effect of low-carbohydrate/high-monounsaturated fatty acids (LC/HMD) nutrition program for patients with diabetes mellitus and stroke. Methods Thirty-seven patients with diabetes mellitus and stroke after percutaneous endoscopic gastrostomy (PEG) were enrolled in this study, and these patients were treated with liquid food nutritional support. All patients were given high-carbohydrate (HCD) nutritional support at the first and second day and then changed to LC/HMD nutrition program. The blood glucose fluctuations were monitored by continuous glucose monitoring(CGM) system. Meanwhile the daily dose of insulin injections, glycosylated hemoglobin (HbA1c) and biochemical indicators were detected. for just admission and just give LC after/HMD nutrition program and three months later on HbA1c and blood biochemical indexes were detected. Results 3 months after LC/HMD nutrition program treatment, the levels of mean amplitude of plasma glucose excursions (MAGE), ratio of hyperglycemia to time, ratio of glycopenia to time, HbA1c, daily dose of insulin injections were significantly improved compared with those at the 2nd of LC/HMD nutrition program treatment and with HCD nutritional support (P < 0.05). Three months after LC/HMD nutrition program treatment, the levels of blood biochemistry index had no significant change (P > 0.05). Three months after LC/HMD nutrition program treatment, the blood glucose fluctuations significantly reduced in all patients. Conclusions For patients with diabetes mellitus and stroke and receiving liquid food treament, LC/HMD nutrition program can significantly improve glycemic index, reduce dependence on insulin, and lower blood sugar fluctuations.

Arginine vasopressin (AVP), a neurohormone and hemodynamic factor implicated in the pathophysiology of hypertension and congestive heart failure, can also act as a growth-stimulating factor. Our previous work demonstrated that AVP is a mitogen for neonatal rat cardiac fibroblasts (CFs). In the present study, we extended our investigations to adult rat CFs to explore whether AVP could induce adult rat CF proliferation and, if so, to identify the mechanism involved. Adult rat CFs were isolated, cultured and subjected to AVP treatment. DNA synthesis and cell cycle distribution were analyzed by [(3)H]-thymidine incorporation and flow cytometry. Cellular extracellular signal-regulated kinase 1/2 (ERK1/2) activity was measured by in vitro kinase assay using myelin basic protein (MBP) as a substrate. Protein expressions of total- and phospho-ERK1/2, p27(Kip1), cyclins D1, A, E were assessed by Western blot. The results showed that AVP stimulated DNA synthesis in adult rat CFs, and the effect was abolished by a V1 receptor antagonist, d(CH(2))(5)[Tyr(2)(Me), Arg(8)]-vasopressin (0.1 μmol/L), but not by a V2 receptor antagonist, desglycinamide-[d(CH(2))(5), D-Ile(2), Ile(4), Arg8]-vasopressin (0.1 μmol/L). AVP induced an activation of ERK1/2, which could be mimicked by the protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA, 30 nmol/L, 5 min), but abolished by depletion of PKC via chronic PMA incubation (2.5 μmol/L, 24 h). In addition, AVP down-regulated protein expression of p27(Kip1), increased protein expressions of cyclins D1, A and E, and induced cell cycle progression from G(0)/G(1) into S stage. Inhibition of ERK1/2 activation by PD98059 (30 μmol/L) abolished the effect of AVP on DNA synthesis, protein expressions of p27(Kip1), cyclins D1, A and E as well as cell cycle progression. These results suggest that AVP is also a growth factor for adult rat CFs. The mitogenic effect of AVP is mediated via V1 receptors and PKC-ERK1/2 pathway. Moreover, AVP modulates the expressions of cell cycle regulatory proteins p27(Kip1) and cyclins D1, A and E, which lie downstream of ERK1/2 activation, and induces cell cycle progression in adult rat CFs.
Animals ; Antidiuretic Hormone Receptor Antagonists ; pharmacology ; Arginine Vasopressin ; pharmacology ; Cell Cycle ; Cell Cycle Proteins ; metabolism ; Cell Proliferation ; Fibroblasts ; cytology ; drug effects ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Myocardium ; cytology ; Phosphorylation ; Protein Kinase C ; metabolism ; Rats ; Signal Transduction ; Tetradecanoylphorbol Acetate ; pharmacology

Objectives To screen the high-risk population of stroke in China using color Doppler flow imaging (CDFI)and to establish a stroke risk prediction model in Chinese population in order to prevent and treat stroke early. Methods Forty-one base hospitals and 715 286 people in the project areas of the first 6 provinces of China conducted routine physical examinations and investigated the related risk factors for cardiocerebrovascular diseases from July 2011 to April 2012 using a cross-sectional study,among them 61 860 patients underwent carotid CDFI screening,and 49 386 of them were high-risk population (exposed to≥3 risk factors). The bilateral common carotid interma-media thickness (IMT),the number of plaques and the degree of carotid stenosis were screened and documented. And whether carotid IMT thickening or not,with or without carotid plaques,and degree of carotid artery stenotic rate 0-49% and≥50% were performed by multivariate logistic regression analysis with the risk factors for stroke,respectively. Results (1)Logistic regression analysis showed that hypertension,atrial fibrillation,smoking,and lack of physical exercise were the independent risk factors for carotid IMT thickening (hypertension:OR,1. 17;95%CI 1. 12-1. 22;atrial fibrillation:OR,1. 15;95%CI 1. 09-1. 21;smoking:OR,1. 13;95%CI 1. 08-1. 17;and lack of physical exercise:OR,1. 12;95%CI 1.08-1. 16). (2)Hypertension,atrial fibrillation, smoking,and diabetes were the independent risk factors for carotid plaque and carotid artery stenosis rate≥50%(carotid plaque,hypertension:OR,1. 55;95%CI 1. 47-1. 62;atrial fibrillation:OR,1. 13;95%CI 1.06-1. 21;smoking:OR,1. 16;95%CI 1. 11-1. 22;and diabetes:OR,1. 30;95%CI 1. 24-1. 37). Carotid stenosis rate≥50%,hypertension:OR,1. 78;95%CI 1.55-2. 03;atrial fibrillation:OR,1. 59;95%CI 1. 39-1. 81;smoking:OR,1. 33;95%CI 1. 20-1. 48;and diabetes:OR,1. 30;95%CI 1. 17-1. 45. Simple obesity did not increase the incidences of carotid atherosclerotic plaque and carotid artery stenosis ≥50%(OR,0. 78, 0.83;95%CI 0. 75-0. 82 ,0. 75-0. 92,respectively). Conclusions Neck vascular ultrasound can be used as a valuable means for screening high-risk population and detecting risk factors of stroke. It has an important clinical significance for the early diagnosis and treatment of carotid atherosclerosis disease.

In order to verify the hypothesis that left ventricular epicardial (LV-Epi) pacing and biventricular (BiV) pacing unavoidably influence the myocardial electrophysiological characters and may result in high risk of malignant ventricular arrhythmia, we calculated, in both normal mongrel dogs and dog models with rapid-right-ventricular-pacing induced dilated cardiomyopathy congestive heart failure (DCM-CHF), the monophasic action potential duration (MAPD) and the transmural dispersion of repolarization (TDR) in intracardiac electrogram together with the QT interval and T(peak)-T(end) (T(p(-T(e)) interval in surface electrocardiogram (ECG) during LV-Epi and BiV pacing, compared with those during right ventricular endocardial (RV-Endo) pacing. To prepare the DCM-CHF dog model, rapid right ventricular pacing (250 bpm) was performed for 23.6+/-2.57 days to the dog. All the normal and DCM-CHF dogs were given radio frequency catheter ablation (RFCA) to His bundle with the guide of X-ray fluoroscopy. After the RFCA procedures, the animals were under the situation of complete atrioventricular block so that the canine heart rates could be voluntarily controlled in the following experiments. After a thoracotomy, ECG and monophasic action potentials (MAP) of subendocardial, subepicardial and mid-layer myocardium were recorded synchronously in 8 normal and 5 DCM-CHF dogs during pacing from endocardium of RV apex (RV-Endo), epicardium of LV anterior wall (LV-Epi) and simultaneously both of the above (biventricular, BiV), the later was similar to the ventricular resynchronization therapy to congestive heart failure patients in clinic. The Tp-Te) meant the interval from the peak to the end of T wave, which was a representative index of TDR in surface ECG. The TDR was defined as the difference between the longest and the shortest MAPD of subendocardial, subepicardial and mid-layer myocardium. Our results showed that in normal dogs, pacing participating of LV (LV-Epi, BiV) prolonged MAPD of all the three layers of the myocardium (P<0.05) with the character that mid-layer MAPD was the longest and subepicardial MAPD was the shortest following subendocardial MAPD. At the same time, TDR prolonged from 26.75 ms at RV-Endo pacing to 37.54 ms at BiV pacing and to 47.16 ms at LV-Epi pacing (P<0.001). Meanwhile in surface ECG, BiV and LV-Epi pacing resulted in a longer Tp-Te) interval compared with RV-Endo pacing (P<0.01), without parallel QT interval prolongation. Furthermore, all the DCM-CHF model dogs showed manifestations of congestive heart failure and enlargement of left ventricles. Based on the lengthening of mid-layer MAPD from 257.35 ms to 276.30 ms (P<0.0001) and increase of TDR from 27.58 ms to 33.80 ms (P equals;0.002) in DCM-CHF model due to the structural disorders of myocardium compared with the normal dog, LV-Epi and BiV pacing also led to the effect of prolonging MAPD of three layers of the myocardium and enlarging TDR. From these results we make the conclusions that prolongation of MAPD of subendocardial, subepicardial and mid-layer myocardium and increase in TDR during pacing participating of LV (LV-Epi, BiV) may contribute to the formation of unidirectional block and reentry, which play roles or at least are the high risk factors in the development of malignant ventricular arrhythmia, especially in case of structural disorders of myocardium. These findings must be considered seriously when ventricular resynchronization therapy is performed to congestive heart failure patients.
Action Potentials ; Animals ; Bundle-Branch Block ; complications ; physiopathology ; Cardiomyopathy, Dilated ; complications ; physiopathology ; Dogs ; Female ; Heart Conduction System ; physiopathology ; Heart Failure ; etiology ; physiopathology ; Heart Ventricles ; physiopathology ; Male ; Torsades de Pointes ; physiopathology ; Ventricular Dysfunction, Left ; physiopathology ; Ventricular Function, Left

Objective To explore the effects of Astragalus polysaccharides on liver injury induced by cadmium chloride. Methods The cadmium chloride solution was administrated i.v. to develope rat model of liver injury. Rats were randomized divided into three groups;control group, model group, Astragalus polysaccharides intervention group. After the 5 weeks, the rats were sacrificed and the livers were weighted, alanine aminotrans ferase(ALT), aspartate aminotransferase (AST) and lactate dehydrogenase(LDH), the contents of cadmium(Cd) was checked by plasma mass spectrometerthe(ICP-MS), the contents of interleukin-2(IL-2) and transforming growth factor-β1(TGF-β1) was measured by ELISA, the the protein expression of Bcl-2 and Bax was observed by immunohisto-chemistry staining method. Results The liver weight was increased in model group, the level of ALT, AST and LDH were also ascended in model group, the contents of Cd, TGF-β1 and the protein expression of Bax all increased in mode group(P＜0.05 or P＜0.01). The content of IL-2 and the protein expression of Bcl-2 were decreased in mode group (P＜0.05 or P＜0.01). Compared with the model group, the liver index was decreased in Astragalus polysaccharides intervention group, the levels of ALT, AST and LDH were also reduced in Astragalus poly-saccharides intervention group, the contents of Cd, TGF-β1 and the protein expression of Bax were all dropped in Astragalus polysaccharides intervention group(P＜0.05 or P＜0.01).The content of IL-2 and the protein expression of Bcl-2 increased in Astragalus polysaccharides intervention group(P＜0.05 or P＜0.01). Conclusions Astragalus polysaccharides may reduce the oxidative stress injury of rats liver cells indued by cadmium chloride, and its mechanism may be explained by regulation of Bcl- 2/Bax protein expression.