Search

Copyright of Journal of Mechanical & Electrical Engineering is the property of Mechanical & Electrical Engineering Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To investigate the mRNA, protein expression levels and the phosphorylation levels of key factors in rapidly accelerated fibrosarcoma/mitogen-activated protein kinase kinase/extracellular regulated protein kinases (Raf/MEK/ERK) pathway, and to clarify the regulatory function of Raf/MEK/ERK pathway in myocardial hypertrophy., Methods: Twenty SD rats were divided into sham-operated group and model group. The myocardial hypertrophy model was established by transverse aortic constriction (TAC). At 12 weeks after TAC, blood samples were collected from the submandibular vein, and the serum was separated to detect the content of N terminal pro B type natriuretic peptide (NT-proBNP). After that, the rats were subjected to echocardiography and hemodynamic measurement. Then the pathological changes of myocardial tissue were observed. And the levels of mRNA, protein expression and the phosphorylation of key factors in Raf/MEK/ERK pathway were detected in myocardial tissue., Results: Compared with sham-operated group, left ventricular end-diastolic interventricular septal thickness (IVSd), left ventricular end-systolic interventricular septal thickness (IVSs), left ventricular end-diastolic posterior wall thickness (LVPWd) and left vebtricular end-systolic posterior wall thickness (LVPWs) in TAC model group were increased significantly (P＜0.05,P＜0.01), left ventricular end-systolic diameter (LVIDs) was decreased significantly (P＜0.01), LV Mass and LW(LV Mass/Weight)were increased significantly (P＜0.05, P＜0.01). The levels of heart rate (HR), left ventricular pressure maximal rate of rise (+dp/dtmax), left ventricular pressure maximal rate of fall (-dp/dtmax) were decreased significantly (P＜0.01). The serum level of NT-proBNP in TAC rat was increased significantly (P＜0.01). The myocardial cells in TAC model group were arranged disorderly, myocardial cell hypertrophy, cytoplasm were increased significantly, and inflammatory cells infiltrated. A large amount of collagen fibers were deposited and large area of myocardial cells were stained blue in TAC rat. The expression levels of phospho-c-Raf (Ser259) and phospho-c-Raf (Ser338) in myocardial tissue were significantly increased (P＜0.01), meanwhile the expression levels of phospho- MEK1/2(Ser217/Ser221) and phospho-ERK1/2 (Thr202/Tyr204) were also significantly increased (P＜0.01)., Conclusion: The regulatory role of Raf / MEK / ERK pathway in cardiac hypertrophy may be through the activation of phosphorylation of c-raf, MEK1, Mek2, ERK1 and ERK2 at specific sites.

Objective: To explore the role of NF-E2-related factor 2(Nrf2) and its related factors in the progression of nonalcoholi steatohepatitis (NASH) by investigating the alterations of lipid metabolism and liver histopathology as well as the changes of mRNA and protein expression levels of Nrf2 and its related factors in rats during NASH progression., Methods: Male SD rats were randomly divided into normal group and model group, which were administrated with high fat diet to establish nonalcoholic steatohepatitis model. The rats from both groups were randomly killed at the end of 4, 12 weeks respectively. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) were detected in the serum and liver tissue; Changes in fat deposition in liver tissue were determined by oil red O staining. HE staining were used to observe the pathological changes of liver tissue and to calculate nonalcoholic fatty liver disease (NAFLD) activity score (hepatic steatosis, inflammation and ballooning degeneration of liver cells). The expression of Nrf2 in liver was detected by immunohistochemical staining. The mRNA and protein levels of Nrf2 and related factors in liver were determined by Realtime PCR and Western blot, respectively., Results: After 4 weeks of high fat diet, the levels of ALT, AST, TC in rat serum and TC, TG, LDL-C in liver were significantly increased compared with that of the normal group (P < 0.01, P < 0.05). After 4 weeks of high fat diet, the levels of ALT, AST, TC, TG in serum and TC, TG, LDL- C in liver increased further (P < 0.01, P < 0.05). Until the 12th week, the content of HDL-C in liver was significantly lower than that of the normal group (P < 0.05). At the end of the 4th or the 12th week, lipid droplets in the model rat liver cells were heavily dyed red and hepatic steatosis increased severely, with ballooning degeneration of liver cells. With the extension of high fat diet feeding time, fat deposition in the liver tissue, hepatic steatosis, NAFLD score, Nrl2 expression were significantly increased (P < 0.01). Expression levels of mRNA and protein of Nrf2, heme oxyenase 1(HO1), NADPH quinone oxidoreductase 1(NQO1), γ-glutamylcysteine synthethase (γ-GCS), glutathione S-transferase (GST) in the model rats increased or decreased at the end of the 4th or the 12th week differentially, (P < 0.01, P < 0.05) with the more significant changes at the end of the 4th week than the 12th week., Conclusion: Nrf2 and its related factors may be involved in the occurrence and development of nonalcoholic fatty liver disease, which may play an important role in the process of NASH formation.

Objective: To study and discuss the effect and mechanism of Hirsutella sinensis mycelium (HSM) on idiopathic pulmonary fibrosis in rats., Method: Forty Wistar rats were divided into five groups: the normal control group, the model control group, the high-dose group (1.0 g x kg(-1) HSM), the low-dose group (0.5 g x kg(-1) HSM), and the positive control group (10 mg x kg(-1) hydrocortisone). In addition to rats in the normal control group, the pulmonary fibrosis model was established by injecting 5 mg x kg(-1) bleomycin into rat tracheas for consecutively 28 days, in order to observe their lung function, lung tissue hydroxyproline, cytokines and pathology., Result: After rats were administered with HSM, 0.5 g x kg(-1) and 1.0 g x kg(-1) HSM could significantly decrease lung index and hydroxyproline content (P<0.01), while notably improving pulmonary function, alveolus inflammation and fibrosis degree (P<0.05, P<0.01); 1.0 g x kg(-1) HSM could decrease significantly protein expressions of TNF-alpha, IL-1beta and TGF-beta1 in lung tissues, while increasing significantly protein expressions of IFN-gamma (P<0.05)., Conclusion: HSM have better effect in treating idiopathic pulmonary fibrosis in rats. Its treatment effect and mechanism are related to the regulation of TNF-alpha, IL-1beta and TGF-beta1 and IFN-gamma imbalance.