To compare the advantages and the disadvantages of the teaching of problem-based learning(PBL) with lecture based learing(LBL) in Pathophysiology with the questionnaire.

In medical education,to cultivate the medical students with high comprehensive quality,we have carried out the teaching reform in Pathophysiology education.

Objective To investigate the role of p38 mitogen-activated protein kinase (p38MAPK) pathway in the protective effect of remifentanil or ischemic preconditioning (IPC) against hepatic ischemia-reperfusion (I/R) injury in rats.Methods One hundred and forty-four male SD rats,weighing 200-250 g,were randomly assigned into 6 group ( n =24 each):sham operation group (group S),I/R group,remifentanil group (group R),IPC group,SB203580 (a specific p38MAPK inhibitor) + remifentanil group (group SB + R),and SB + IPC group.The animals were anesthetized with intraperitoneal 20％ urethane 1 mg/kg.Partial liver ischemia was produced by clamping the hepatic pedicle supplying left lobe and middle lobe for 30 min,followed by 120 min reperfusion.In group R,remifentanil was infused intravenously at 2μg· kg- 1 · min- 1 starting from 30 min before ischemia until the end of reperfusion.In IPC group,the rats were subjected to 3 episodes of 5 min ischemia at 5 min intervals before I/R.SB203580 0.2 mg/kg was injected intravenously at 5 min before remifentanil infusion or IPC in groups SB + R and SB + IPC,and the equal volume of normal saline was given in the other groups.Six rats in each group were selected at 30,60,90 and 120 min of reperfusion and venous blood samples were taken from inferior vena cava for measurement of serum ALT and AST activities and concentrations of TNF-a and 1L-1β.The rats were then sacrificed and liver tissues were taken for microscopic examination and determination of phosphor-p38MAPK expression by Western blot.Results Compared with group S,serum AST and ALT activities and serum levels of TNF-α and IL-1β were significantly increased at each time point (P ＜ 0.05) and pathological injury was aggravated in group I/R.Compared with group I/R,serum AST and ALT activities and serum levels of TNF-a and IL-lβ were significantly decreased and phosphor-p38MAPK expression was up-regulated at 90 min of reperfusion in groups R and IPC ( P ＜ 0.05).The serum AST and ALT activities and serum levels of TNF-α and IL-1β were significantly increased,phosphor-p38MAPK expression was down-regulated at 90 min of reperfusion ( P ＜ 0.05),and pathological injury was aggravated in group SB + R compared with group R,and in group SB + IPC compared with group IPC.Conclusion Activation of p38MAPK pathway and inhibition of inflammatory response may be involved in the mechanism by which remifentanil or IPC reduces the hepatic I/R injury in rats.

Objective To investigate the protective effect of propotol against hepatic ischemiareperfusion injury in rats on mitochondrial permeability transition pore (MPTP) and the mechanism of GSK-3β.Methods Thirty SD rats were randomly assigned into five groups (n =6):sham operation group (S group),ischemia reperfusion group (I/R group),CsA pretreatment group (C group),propofol pretreatment group (P group),and propofol plus atractyloside pretreatment group (A + P group).Nauta liver ischemia-reperfusion rat model was used.Liver lobes were subjected to warm ischemia for 60min and then reperfusion for 120 min.In P group,propofol [12 mg/(kg · h)] was administered in the femoral vein for 30 min before ischemia until the end of reperfusion.In C group,CsA (2 mg/kg) was administered in the femoral vein for 20min before ischemia.In A + P group,20 μmol/kg of atractyloside was given through the femoral vein 10min before the injection of propofol.Rats were sacrificed at the end of reperfusion,and venous blood and hepatic tissue specimens from the same part of ischemia were obtained from different groups.Results Compared with S group,the AST and ALT levels were increased significantly,mitochondrial swelling were increased and mitochondrial membrane potential were decreased significantly in I/R group and A + P group.Casepase-3 were increased significantly and p-GSK3β Ser9 were decreased significantly in I/R group and A + P group.Compared with I/R group,the content of AST and ALT were decreased significantly,mitochondrial swelling were decreased and mitochondrial membrane potential were increased significantly,casepase-3 release were decreased significantly and p-GSK3β Ser9 were increased significantly in P group and C group.GSK-3β in each group displayed no significant difference.Conclusions Propofol can significantly reduce hepatic ischemia-reperfusion injury.The protective effect of propofol may be achieved via the inhibition of GSK-3β activation,increased p-GSK-3β Ser9 level,suppressing MPTP opening and decreasing hepatocytes apoptosis.

Objective To explore biomechanical properties and clinical results of a new type of dynamic Hoffmann external fixator(NDHEF)for tibial shaft fractures.Methods Fifteen specimens of adult tibia were randomly divided into three groups and osteotomized obliquely in the mid part of the tibia.These specimens were fixed with NDHEF,improved Hoffmann external fixator(IHEF)and maltifunctional external fixator(MEF)re- spectively.The axial compression,bending,torsion and stress shielding tests were performed on the specimens in each group for biomechanical comparison.From 1995 to 2004,40 cases of open tibiofihular fractures were treated with NDHEF and 88 cases with IHEF and their clinical results were analyzed and compared.Results The biomechanical tests showed that the compressive rigidity,bending rigidity and torsion rigidity of NDHEF were similar to those of IHEF(P＞0.05)but significantly stronger than those of MEF(P＜0.05).The stress shielding of NDHEF was obviously weaker than that of other external fixators(P＜0.05).All the 128 cases were followed up for 12 to 36 months(average,16.8 months).The mean substantial bone healing time for NDHEF treatment was 22.3 weeks and that for IHEF was 26.8 weeks.The difference was significant(P＜0.05).The rates of delayed union and malunion were all 7.5% for NDHEF,but 15.9% and 4.5% respectively for IHEF.The difference was insignificant (P＞0.05).Conclusions The biomechanical performance of NDHEF is superior to that of IHEF,for it can diminish the stress shielding and accelerate bone healing.It is a good external fixator for tibial fractures.

Objectives: To evaluate mice as experimental animal for Chlamydia pneumoniae, a common cause of acute respiratory infections in human.　Methods: Intranasal inoculation of Icr mice with C. Pneumoniae induced a prolonged course of lung infection, as demonstrated by persistence of lung pathology(60 days).　Results: Icr mice were susceptible to C. pneumoniae. Lung pathology was characterized by patchy interstitial pneumonitis with predominately neutrophil leukocyte infiltration in the early(7 days) and lymphocytes infiltration in the later stages(14 days later) of infection.　Conclusions:Icr mice were susceptible to C. pneumoniae and the mouse model is useful for the investigation of the pathogenesis of C. pneumoniae infection.

Adult ; Fever ; etiology ; Gastrointestinal Hemorrhage ; etiology ; Humans ; Male ; Polyps ; complications ; Stomach Diseases ; complications

Objective To investigate the protective effect of propofol pretreatment against hepatic ischemia-reperfusion injury and oxidative stress in rats and the mechanism of the role of GSK-3 β.Methods Sixty SD rats were randomly divided into four groups:sham operation group (S group),ischemia-reperfusion group (I-R group),propofol pretreatment group (P group),TDZD-8 pretreatment group (T group).The hepatic ischemia-reperfusion rat models were established by the method of Nauta.Rats were subjected to 30-min,60-min and 90-min 70％ warm ischemia of liver followed by reperfusion for 120 min,respectively.Propofol (12 mg/kg · h) was injected via femoral vein 30 min before ischemia till the end of reperfusion in P group and TDZD-8 (1 mg/kg) were injected via femoral vein 20 min before ischemia in T group.The animals were killed at 120 min after reperfusion.Blood samples and the liver tissue were obtained.The levels of alanine aminotransferase (ALT),aspartate aminotransferase (AST),lactate dehydrogenase (LDH),malondialdehyde (MDA) and superoxide dismutase (SOD) were analyzed.Liver morphological changes were observed using optical microscopy.p-GSK-3β Ser9 and total GSK-3 β expression was determined by Western blot.Results Compared with S group,AST,ALT,LDH and MDA level was increased,SOD level was reduced,and p-GSK-3 β Ser9 expression was significantly reduced in I-R group.Compared with I-R group,the content of AST,ALT,LDH and MDA was reduced significantly,SOD increased significantly,and the content of p-GSK-3β Ser9 increased significantly in P group and T group.There were no significant differences between P group and T group.The hematoxylin-eosin staining of hepatic tissues revealed in I-R group had severe structural damage and periportal inflammatory cells infiltrated,hepatocyte necrosis and sinusoidal congestion.In P group and T group,liver tissues had normal structure,less cell death,edema and inflammatory cell infiltration.Conclusions Propofol can significantly reduce hepatic ischemia reperfusion injury by reducing oxidative stress and lipid hydroperoxides.This protective effect of Propofol may be associated with the inhibition of GSK-3 β by GSK-3 β Ser9 phosphorylation.

Local focal adhesion kinase (FAK) is a non-receptor intracellular tyrosine kinase that plays an important role in tumor initiation, development, metastasis and invasion, and is considered to be an important target for the development of antineoplastic drugs. It has both kinase-dependent and non-kinase-dependent scaffolding functions. However, traditional small molecular inhibitors can only inhibit its kinase-dependent activity, so it is difficult to target the kinase-independent scaffolding function. Therefore, there is an urgent need for novel strategies to enhance FAK targeting to lay the foundation for determining the druggability and discovery of FAK inhibitors. Proteolysis targeting chimera (PROTAC) is a new drug development strategy that can recruit E3 ligase to specifically ubiquitinylate target proteins for degradation through the proteasome system. The unique mechanism of action of the PROTAC system could be used to target and degrade the FAK protein, thus eliminating the scaffolding function of FAK. In this review, FAK protein, the signaling pathway, and small molecule inhibitors are briefly described, and the latest research progress in targeting the degradation of FAK using PROTAC technology is summarized.

Objective:To investigate the expression of circhipk3 in microglial cells in heat-induced neurological injury, and to preliminary analyze the effect of circhipk3 on microglial polarization in heat-induced neurological injury.Methods:Mice were randomly (random number) divided into a control group and a heat radiation disease 0.8 h group (HS 0.8), a heat radiation disease 8h group (HS 8), and a heat radiation disease 24 h group (HS 24). By establishing a mouse model of heat shock (HS), heat-damaged brain tissue was obtained, microglia were isolated and RNA was extracted. Quantitative PCR method was used to detect M1 and M2 marker molecules in microglia, and to evaluate the polarization direction and type of microglia. The expression level of circhipk3 was detected in microglial cells in heat-induced neurological injury, and the effect of circhipk3 on microglial polarization was further elucidated by intervening the expression of circhipk3 in microglial cells.Results:The expression of CD45 and CD11-b in the HS 8 group was significantly higher than that in the control group [(4.41±0.18) vs. (1±0.15), P=0.000], [(3.47±0.19) vs (1±0.15), P=0.000] , and the CD45 and CD11-b of the HS 24 group was significantly lower than that of the HS 8 group [(1.34±0.15) vs. (4.41±0.18), P=0.000], [(1.38±0.21) vs. (3.47±0.19), P= 0.001]. At the same time, the expression of CD206, FIZZ and Arg1 in the HS 8 group started to increase compared with the control group [(1.59±0.16) vs. (1±0.12), P=0.014], [(1.62±0.15) vs. (1±0.15), P=0.002 ], [(2.23±0.28) vs. (1±0.19), P=0.004], and CD206, FIZZ, and Arg1 in the HS 24 group were significantly higher than those in the control group [(2.67±0.20) vs. (1±0.12), P=0.002], [(2.19±0.15) vs. (1±0.15), P=0.000], [(3.04±0.18) vs. (1±0.19), P=0.001]; circhipk3 mimicis significantly increased the expression of Arg1 [(7.26± 0.06) vs. (3.86±0.06), P=0.000]; at the same time, circhipk3 inhibitor promoted the expression of CD45 and HO-1 [(2.96±0.03) vs. (1.63±0.09), P=0.000], [(2.52±0.10) vs. ( 1.30±0.02), P=0.000]. Conclusions:Microglial cells are predominantly M1-type in early neurological injury of heat radiation disease. HO-1 may be one of the microglial M1-type markers. The high expression of circhipk3 in microglial cells mainly promotes its transformation to M2 type.