Effect of ACE2 deletion on vasoconstriction reactivity of aortic segments in mice with tourniquet shock / 中国病理生理杂志

AIM:To observe the effect of angiotensin-converting enzyme 2(ACE2)deletion on vasoconstric-tion reactivity of aortic segments in ACE2 knockout(KO)mice with tourniquet shock(TS).METHODS:The 8-month-old male mice with C57BL/6 background were divided into wild-type(WT)control group,WT-TS group,KO group and KO-TS group,with 10 mice in each group,of which five were used for determination of vascular reactivity,and the other five for the other assays.The hindlimbs of the mice in WT-TS group and KO-TS group were ligated with tourniquet for 2 h and loosened for 4 h.The mice in WT group and KO group were subjected to the same treatment except for tourniquet liga-tion.The vasoconstriction reactivity of the aorta was measured on tensiometer.The morphological damage of the aorta was evaluated by vascular histopathology.Western blot was used to detect the expression of AT1,MAS,ACE and ACE2 pro-teins in aorta.The serum levels of angiotensin(Ang)Ⅱ and Ang-(1-7)were determined by enzyme-linked immunosorbent assay.RESULTS:Compared with WT group,the mice in WT-TS group had lower vascular reactivity to norepinephrine(NE)and obvious vascular lesions.The expression of ACE protein increased significantly(P＜0.01),while the expres-sion of ACE2 decreased(P＜0.05).The expression of AT1 protein in aorta decreased significantly,the expression of MAS protein increased significantly,and the AT1/MAS ratio decreased(P＜0.01).Serum Ang II level increased,serum Ang-(1-7)level decreased,and Ang Ⅱ/Ang-(1-7)ratio increased(P＜0.05).Compared with WT group,vascular reactivity in KO group increased at low concentration of NE(＜10-7 mol/L),and decreased at high concentration(＞10-7 mol/L)without vascular lesion.The expression levels of aortic AT1,MAS and ACE were all elevated(P＜0.05).The serum level of Ang Ⅱ increased(P＜0.05),but the level of Ang-(1-7)had no obvious change.Compared with KO and WT-TS groups,the aortic reactivity in KO-TS group subtracted apparently(P＜0.05),representing its curve shifting to the right obviously.The morphological damage aggravated slightly,and the expression of AT1 and ACE increased slightly in KO-TS group com-pared with WT-TS group(P＜0.05).However,the expression of MAS increased significantly in vascular tissue(P＜0.01).The serum levels of Ang Ⅱ and Ang-(1-7)further increased and decreased,respectively,and the Ang Ⅱ/Ang-(1-7)ratio increased(P＜0.01).CONCLUSION:Deficiency of ACE2 induces severe aortic hyporeactivity to NE during TS,which may be related to the increased imbalance of renin-angiotensin system in ACE2 gene knockout mice.

Application of virtual medical experimental platform on formative evaluation of functional experimental teaching / 中华医学教育探索杂志

Based on the combination of formative evaluation and summative evaluation, the newly-built virtual experimental platform was applied to the functional experimental assessment of clinical students. Its effects were observed by the process evaluation of "daily performance-virtual and real operation + written exam" and feedback from teachers and students. The results showed that daily performance, experimental operation, experimental report and final score of students in the experimental group who received the teaching by virtual experimental platform were significantly better than those in the control group; the students' interests in learning and self-learning ability in the experimental group were also significantly improved. This research showed that the introduction of virtual experimental platform into the teaching evaluation of diversified functional experiment enriches the contents and ways of formative evaluation, so as to improves students' experimental skills, and further enhance the effects of experimental teaching.

Application of virtual medical experimental platform on formative evaluation of functional experimental teaching / 中华医学教育探索杂志

Based on the combination of formative evaluation and summative evaluation,the newlybuilt virtual experimental platform was applied to the functional experimental assessment of clinical students.Its effects were observed by the process evaluation of "daily performance-virtual and real operation + written exam" and feedback from teachers and students.The results showed that daily performance,experimental operation,experimental report and final score of students in the experimental group who received the teaching by virtual experimental platform were significantly better than those in the control group;the students' interests in learning and self-learning ability in the experimental group were also significantly improved.This research showed that the introduction of virtual experimental platform into the teaching evaluation of diversified functional experiment enriches the contents and ways of formative evaluation,so as to improves students' experimental skills,and further enhance the effects of experimental teaching.

Therapeutic effect of low dose tolvaptan combined with furosemide in elderly patients with chronic heart failure and diuretic resistance / 中华老年心脑血管病杂志

Objective To observe the therapeutic effect of low dose tolvaptan combined with furosemide in ederly patients with CHF and diuretic resistance (DR).Methods Eighty-five elderly patients with CHF and DR were divided into observation group (n=43) and control group (n=42).The patients in observation group were treated with cardiotonics and hypotensors plus oral tolvaptan (15 mg/d) combined with intravenous furosemide (40 mg/d).The therapeutic effect of low dose tolvaptan combined with furosemide was assessed.Results The average urinary volume was larger,and the LVEDV was significantly lower in two groups after treatment than before treatment (P＜0.05).The urinary volume was significantly larger while the LVEDV was significantly lower in observation group than in control group (2.89±0.87 L/d vs 2.43±0.49 L/d,P=0.01;103.6±21.5 ml vs 116.7±24.3 ml,P=0.01).The total effective rate was significantly higher in observation group than in control group (86.0％ vs 71.4％,P=0.01).Conclusion Low dose tolvaptan combined with furosemide can effectively improve the DR and therapeutic effect in elderly CHF patients,and is thus worth popularization in clinical practice.

Changes of lung AT1R and Mas receptor protein expression in lung tissue of mice with lung injury after limb ischemia-reperfusion / 中国病理生理杂志

AIM: To explore the role of imbalance of local renin-angiotensin system (RAS) in lung injury by observing the changes of angiotensin Ⅱ type 1 receptor (AT1R) and Mas receptor protein expression in the lung and the degree of lung injury subject to limb ischemia-reperfusion (LIR) in the mice.METHODS: Male ICR mice (n=42, 8 weeks old) were randomly assigned into 7 groups (6 in each group), including control group and 6 model groups with LIR of 0.5 h, 1 h, 2 h, 4 h, 6 h and 12 h reperfusion.Tourniquets were used to block the blood flow of the hind limbs of the ICR mice and were released after 2 h ischemia to initiate reperfusion.The mice were sacrificed by eyeball blood withdrawal at different time points after reperfusion.The organ coefficient and wet/dry weight ratio (W/D) of the lung tissue were calculated.Bronchoalveolar lavage fluid (BALF) was taken for cell counting and protein concentration measurement.The histopathological changes of the lung tissues was observed, and the pathological score was calculated.The protein expression of AT1R and Mas receptor in the lung tissues was determined by Western blot.RESULTS: The organ coefficient, W/D of lung tissue, and cell number and protein concentration in BALF of model groups were significantly higher than those in control group after LIR.The pathological changes were found in the lung tissue of model mice, including alveolar capillary dilation and congestion, edema, inflammatory cell infiltration in peripheral vascular, alveolar and bronchial walls, alveolar septal thickening and inflammatory cell infiltration.The lung injury score was elevated gradually along with the extension of reperfusion time.The protein expression of AT1R began to increase at reperfusion time points of 0.5 h and 1 h.With the extension of reperfusion time, the protein expression of AT1R decreased gradually.Conversely, the protein expression of Mas receptor increased gradually with prolonged reperfusion.CONCLUSION: LIR induces acute lung injury gradually.The imbalance of AT1R and Mas receptor expression may be involved in the damage process.

Mechanism of Ac-SDKP on regulating CREB signal and Smad signal in order to restrain silicotic fibrosis / 实用医学杂志

Objective To observe the function of Ac-SDKP on p-CREB,p-Smad2/3 signal and restraining silicotic fibrosis.Methods Wistar rats were randomly divided into:control group;silicosis group;Ac-SDKP post-treatment group;Ac-SDKP pre-treatment group.The morphology of lung tissue was observed by Van Gieson stain-ing.The expression of α-SMA,cAMP,PKA,p-CREB and p-Smad2/3 protein were assessed by Western blot.The colocalization of p-Smad2/3 and α-SMA were detected by immuno-fluorescence. Results In silicosis group,the deposition of collagen were visible in the fibrotic area,the expression of α-SMA and p-Smad2/3 increased signifi-cantly,and the expression of cAMP,PKA and p-CREB decreased significantly. After Ac-SDKP treatment,the expression of cAMP,PKA and p-CREB were significantly up-regulated,the expression of -SMA and p-Smad2/3 protein were significantly down-regulated,lung tissue damage and collagen deposition decreased. Conclusion By activating the signal of cAMP/PKA/p-CREB,Ac-SDKP was capable of restraining the expression of p-Smad2/3,so as to restrain silicotic fibrosis.

Effect of N-acetyl cysteine pathway on expression of intermediate conductance Ca2+-activated K+ channels in cardiac fibroblasts of AGT-REN double transgenic hypertension mice / 吉林大学学报(医学版)

Objective:To investigate the relationship between the level of oxidative stress and the expression of intermediate conductance calcium activated potassium channel (KCa3.1) protein in the cardiac fibroblasts (CFs) during hypertension process,and to clarify the role of KCa3.1 in cardiac fibrosis and its mechanism.Methods:The CFs of male C57B6 and AGT-REN double transgenic hypertension (dTH) mice were cultured and the wild C57B6 mouse CFs were used as control group.The CFs of dTH mice were randomly divided into high blood pressure group (dTH) and N-acetyl cysteine group (NAC).The CFs were treated with different concentrations of NAC for 24 h.The cell proliferation was detected by MTT and double dichlorofluorescein (DCFH-DA) probe was used for the detection of cellular reactive oxygen species (ROS) expression;Western blotting was employed to detect the expressions of collagen Ⅰ,collagen Ⅲ,Kca3.1 channel protein and the changes of PI3K signaling pathway protein phosphorylation.Results:The ROS production and protein expression of Kca3.1 channel of the dTH mice on 4,8,12 months were increased compared with 2 months (P＜0.05 or P＜0.01);the results of MTT suggested that the proliferation rates of CFs were 165.9％,138.72％,110.92％ and 109.82％ after administration of 1×10-6,1× 10 5,1× 10 4 and 1 × 10-3 mol · L-1 NAC in the dTH mice,and 1 × 10-4 and 1 × 10 3 mol · L-1 NAC significantly inhibited the proliferation of CFs.Compared with control group,the secretion of collagen Ⅰ and Ⅲ of CFs in the TH mice was decreased in 1 × 10-4 mol · L-1 NAC group (P＜0.01).The results of Western blotting showed that compared with control group,the expression level of Kca3.1 channel protein in CFs of the TH mice in 1 × 10-4 mol · L-1 NAC group was decreased (P＜0.01).Compared with control group,the p-AKT/T-AKt in CFs of the dTH mice was increased (P＜0.01);but in NAC group,the p-AKT/T-AKt was lower than that in dTH group (P＜0.01).Conclusion:NAC can inhibit the expression of KCa3.1 channel protein in CFs of the dTH hypertensive mice,which may be related to increasing the phosphorylation of AKt/PI3K signaling pathway.

Effect of N-acetyl cysteine pathway on expression of intermediate conductance Ca2+-activated K+ channels in cardiac fibroblasts of AGT-REN double transgenic hypertension mice / 吉林大学学报(医学版)

Objective:To investigate the relationship between the level of oxidative stress and the expression of intermediate conductance calcium activated potassium channel (KCa3.1) protein in the cardiac fibroblasts (CFs) during hypertension process,and to clarify the role of KCa3.1 in cardiac fibrosis and its mechanism.Methods:The CFs of male C57B6 and AGT-REN double transgenic hypertension (dTH) mice were cultured and the wild C57B6 mouse CFs were used as control group.The CFs of dTH mice were randomly divided into high blood pressure group (dTH) and N-acetyl cysteine group (NAC).The CFs were treated with different concentrations of NAC for 24 h.The cell proliferation was detected by MTT and double dichlorofluorescein (DCFH-DA) probe was used for the detection of cellular reactive oxygen species (ROS) expression;Western blotting was employed to detect the expressions of collagen Ⅰ,collagen Ⅲ,Kca3.1 channel protein and the changes of PI3K signaling pathway protein phosphorylation.Results:The ROS production and protein expression of Kca3.1 channel of the dTH mice on 4,8,12 months were increased compared with 2 months (P＜0.05 or P＜0.01);the results of MTT suggested that the proliferation rates of CFs were 165.9％,138.72％,110.92％ and 109.82％ after administration of 1×10-6,1× 10 5,1× 10 4 and 1 × 10-3 mol · L-1 NAC in the dTH mice,and 1 × 10-4 and 1 × 10 3 mol · L-1 NAC significantly inhibited the proliferation of CFs.Compared with control group,the secretion of collagen Ⅰ and Ⅲ of CFs in the TH mice was decreased in 1 × 10-4 mol · L-1 NAC group (P＜0.01).The results of Western blotting showed that compared with control group,the expression level of Kca3.1 channel protein in CFs of the TH mice in 1 × 10-4 mol · L-1 NAC group was decreased (P＜0.01).Compared with control group,the p-AKT/T-AKt in CFs of the dTH mice was increased (P＜0.01);but in NAC group,the p-AKT/T-AKt was lower than that in dTH group (P＜0.01).Conclusion:NAC can inhibit the expression of KCa3.1 channel protein in CFs of the dTH hypertensive mice,which may be related to increasing the phosphorylation of AKt/PI3K signaling pathway.

Changes of aortic contractile reactivity and RAS components after tourni-quet shock / 中国病理生理杂志

AIM: To investigate the role of renin-angiotensin system (RAS) disequilibrium in hyporeactivity and injury of aorta after tourniquet shock ( TS) by observing the changes of aortic contractile reactivity and RAS components after TS.METHODS:Male C57BL/6 mice (8 months old) were divided into 7 groups including control group and 6 mod-el groups.The mice in model groups were sacrificed at reperfusion of 10 min, 1 h, 2 h, 4 h, 6 h and 12 h.The mice in control group were not subjected to tourniquet ligation .The Doppler flowmetry was used to determine the limb blood flow . The carotid artery catheter was applied to detect the blood pressure .The isolated vascular tension tester was available to measure the reactivity of the aorta .HE staining combined with transmission electron microscopy was used to evaluate the morphology of injured aortas .The protein expression of AT 1 receptor , Mas receptor , ACE and ACE2 was measured by Western blot.The serum contents of Ang Ⅱand Ang (1-7) were detected by ELISA.RESULTS:Compared with control group, the blood flow in model groups decreased gradually with the prolongation of reperfusion time .The blood pressure in-creased at 10 min after reperfusion, and then decreased gradually.Accordingly, vascular reaction to norepinephrine (NE) in-creased at 10 min and then descended .The vascular reactivity reached the lowest level at 4 h.Morphological injury score in-creased gradually .Vascular AT1 receptor and ACE2 proteins were reduced , while Mas receptor and ACE proteins were up-regulated compared with control group .The content of AngⅡin the serum elevated, while the content of Ang (1-7) was re-duced.CONCLUSION:The mechanism of aortic reaction to NE increased temporarily in the early stage of shock and then decreased .It may be related to the morphological injury of aorta and the imbalance of RAS .

Reconstruction of failed urethroplasty with different tissues and materials for hypospadias / 中华泌尿外科杂志

Objective To study the efficacy and complications of reconstruction of failed urethro-plasty for hypospadias with pedicle flap , bladder mucosa , buccal mucosa , and biological patch . Methods 23 patients were enrolled from Jul .2005 to Dec.2011.8 patients, with good local skin condition , were performed with pedicle flap urethroplasty .The other 15 patients, with bad local skin condition or with long segment urethral stricture , were performed with free grafts , including 6 bladder mucosa , 7 buccal muco-sal and 2 biological patch. Results Of the 23 cases, 7 cases were cured by one phase operation .There were 16 (16/25) cases had complications.3 (3/16) cases were failed because of serious infection (2 pedi-cle flap, 1 bladder mucosa ) .The failed cases were implemented with urethroplasty 6 months later by the buccal mucosa installments operation .4 (4/16) cases had solitary urethral fistula (1 pedicle flap, 2 bladder mucosa, and 1 buccal mucosal), who were successfully treated with simple fistula repair 3 to 6 months later. 9 ( 9/16) cases had urethral stricture ( 2 pedicle flap , 3 bladder mucosa , 3 buccal mucosal , and 1 biologi-cal patch graft ) , who were treated with urethral sound and got good result .We had reconstructed the urethra using mucosa graft onlay urethroplasty .All of the 23 patients were followed up with an average of 14.5 ( 6-24) months.23 cases were satisfied with the stretched penis , urination and no need to expand the urethra more than 6 months.3 cases were not satisfied with penile appearance .After communication, these patients did not require a further penis orthopedic surgery . Conclusions Pedicle flap, bladder mucosa , buccal mucosa and biological patch can be used in urethral repair and construction of failed urethroplasty for hypos -padias.Urethral sound dilation plays an important role in hypospadias repair .

BQ123 Alleviates Lung Injury Following Limb Ischemia-Reperfusion in Rats / 医药导报

Objective To observe BQ123 on lung tissue injury following ischemia-reperfusion of hind limbs in rats.Methods A total of 30 male SD rats were randomly divided into control,I-R,and BQ123 groups,with 10 rats in each group. After 4- hour of ischemia and 4-hour of reperfusion to the hind limbs, ET-1 was measured by radioimmunoassay, levels of myeloperoxidase (MPO) and malondialehyde (MDA) were examined by biochemical method,and the content of P-selectin was examined by ELISA. Immunohistochemical method was used to detect the expressions of Fas,Bcl-2 and Caspase-3 in lung tissues. Pulmonary apoptosis was examined by means of TdT-mediated dUTP nick end labeling ( TUNEL) . Results Compared with the control group,the levels of ET-1,MPO,MDA and P-selectin in lung tissues were all increased significantly in I-R group ( P<0. 01). The expressions of Fas,Bcl-2 and Caspase-3 were 0. 294±0. 003,0. 108±0. 005,and 0. 174±0. 003,significantly up-regulated in the I-R group. The apoptosis rate [(18. 83±2. 86)%] was significantly increased in the I-R group (P<0. 01). Compared with I-R group,the tissue contents of ET-1,MPO,MDA and P-selectin were significantly lowered in BQ123 group (P<0. 01). The expression levels of Fas (0. 115±0. 007) and Caspase-3 (0. 159±0. 006) were decreased,but the expression of Bcl-2 was increased (0. 128±0. 005). The apoptosis rate in BQ123 group was significantly lower [(10. 67±2. 16)%,P<0. 01].Conclusion BQ123 may have protective effects on lung tissue after limb ischemia-reperfusion in rats by means of improving neutrophil aggregation and reducing the expression of proteins related to cell apoptosis.

Exploration of functional experiment evaluation system to cultivate practical medical talents / 中华医学教育探索杂志

Functional experiment plays an important role in basic theory and clinical practice. For training high-quality medical talents in medical colleges,many improvements have been made in the functional experiment teaching and certain effects have been obtained. But a comprehensive evalu-ation system was still needed. Clinical medical students of 2010 grade were taken as the appraisal objects. Assessment content,methods and standards were designed according to the basic requirements of functional experiment. Students were evaluated by ordinary performance,test papers and experiment competition. Practice showed that the system was of significant importance in improving the experi-mental teaching quality and developing students' practical ability and comprehensive quality.

Protective effect of ischemia preconditioning and the role of nitric oxide on the small intestines injury following hind limbs ischemia reperfusion in rat * / 重庆医学

Objective To observe the protection effect of ischemic preconditioning to small intestines injury after limbs ischemia reperfusion ,and investigate the role of nitrogen monoxidum in the process .Methods 52 male Wistar rats were randomly divided in-to Sham group ,limbs ischemia-reperfusion (IR) group ,IPC + IR group and Nω-nitro-L-arginine methylester (L-NAME) group . The value of diamine oxidase (DAO) and nitrogen monoxidum (NO) in plasma and gut tissue ,the content of fluorescein isothiocya-nate lipopolysaccharide (FITC-LPS) in plasma ,and the value of cyclic guanosine monophosphate (cGMP) and malondialehyde (MDA) in gut tissue were measured ,respectively .The expression of P-selection and Caspase-3 were measured by immunohisto-chemistry .The apoptosis of intestinal cells was detected by terminal deoxynucleotidyl transferase -mediated dUTP nick end labe-ling (TUNEL) and the results were analysed quantitatively by automatic image analytical system .Results Compared with the LIR group ,the values of DAO and FITC-LPS in plasma decreased obviously in the IPC group ,and the level of NO in plasma increased obviously (P<0 .01) .The values of DAO ,NO and cGMP in gut tissue increased obviously ,the level of MDA and the expression of Caspase-3 and the apoptosis index (AI) were significantly decreased in IPC group (P<0 .01) .Compared with the IPC group ,the value of DAO and FITC-LPS were higher and the level of NO was lower in plasma of the L-NAME group (P<0 .01) .The values of DAO ,NO and cGM P in gut tissue obviously decreased ,the level of MDA significantly increased ,and the expression of Caspase-3 and the AI significantly upregulated in L-NAME group than those in IPC group (P<0 .01) .Conclusion IPC can improve the small intestine injury and the apoptosis following hind limbs ischemia reperfusion which may correlated with the increase in the level of NO .

Expression of SARS-CoV functional receptor angiotensin-converting enzyme 2 in nephritic epithelium of primates / 中国病理生理杂志

AIM:To investigate the expression of angiotensin-converting enzyme 2 (ACE2) in nephritic epithelium of primates. METHODS:The expression of ACE2 in Vero E6 cells was detected by the techniques of RT-PCR and immunocytochemistry (ICC) techniques. The distribution of ACE2 protein in kidney tissues of two Rhesus monkeys and two normal human cases was observed by immunohistochemistry (IHC) techniques. RESULTS:Vero E6 cells were found to express both ACE2 mRNA and protein. ACE2 protein was mainly located in epithelium of proximal tubules of Rhesus monkey and human kidney. CONCLUSION:The expression of ACE2 in epithelium of primate kidney may provide the condition for SARS-CoV entry,which may be one of the reasons for inducing renal damage in SARS patients.

Changes of nitric oxide synthase in lung of rats after ischemic reperfusion of hind limbs / 中国病理生理杂志

AIM: To study the distribution of nitric oxide synthase (NOS) in normal lung of rats, and the changes in distribution and activity of NOS in lung of rats suffering from limb ischemia reperfusion (LIR). METHODS: Using tourniquet, the model rats undergoing ischemia reperfusion were made. Using ?-ANDPH-d histochemical method, computer analysis of image and spectrophotography, the distribution of NOS in normal lungs of rats, and the changes in distributon and activity of NOS in lung of rats suffering from limb ischemia reperfusion (LIR) were observed. RESULTS: Histochemically, in normal rats, the NOS positive staining was found in epithelial cells of respiratory duct including bronchi, alveolar duct as well as in endothelium of pulmonary vessels, and the negative staining was found in pneumonocytes. In LIR rats, the above NOS staining were significantly stronger than that in normal one, and positive staining was also found in vascular smooth muscle and pneumonocytes. Biochemically, the results showed that the values of lung NOS, NO in LIR group increased significantly compared with the normal control. CONCLUSION: NO may play an important role not only in physiology of lung but also in pathophysiology of acute lung injury following LIR. [