Tissue engineering heart valves need a scaffold with good quality for cell growth and adherence. The psesent work was to investigate the biomechanics and biocompatibility of acellular porcine heart valves. The method used in this study could completely remove the cellular components in the porcine heart valve leaflets. Compared with fresh leaflets,the water content of acellular leaflets increased, and the soluble protein content decreased significantly. But the shrinkage temperature, thickness, stretch rate and strength at rupture of the acellular leaflets were not altered significantly compared with the fresh leaflets. After implanting the acellular leaflets subcutaneously in rabbits,it was proved that host cells could grow into the leaflets along the collagen fibers. These results suggested that acellular porcine heart valve leaflets could be used as a scaffold to construct tissue engineering heart valves with satisfacfory mechanical property and tissue compatibility.

Objective To remove cellular compenents from porcine aortic valve with different reagents, providing acellular tissue matrix(ACTM) scaffolds for tissue engineering of heart valve. Methods Different detergents (TritonX-100、Sodium dodecyl sulfate and sodium deoxycholate) and enzyme (trypsin) were used to remove cells and its, compenents from porcine aortic valves, respectively. According to the different detergents, specimens of porcine aortic valve were divided into three groups(Sodium dodecyl sulfate, sodium deoxycholate, and Triton X-100). Specimens were observed grossly uncroscopically. Haematoxylin-eosin and DNA assay was performed to confirm the removal of cells. Transmission electron microscope was used to observe the integrity of collagen and elastin. The changes of mechanical properties were also studied. Results The cells were removed effectively from cusps and roots of porcine aortic valves by Triton X-100 and sodium dodecyl sulfate in 96 h. Sodium deoxycholate could not effectively remove the cells from the root of aortic valve. Treatment with SDS disrupted collagen fiber structure of porcine aortic valve, resulting in poor mechanical properties. Treatment with TritonX-100 result in an acellular porcine aortic valve matrix with retention of near normal structure and mechanical properties. Conclusion Porcine aortic valve can be successfully decellularised with retention of near normal structure and mechanical properties by Triton X-100.

Objective:To amplify and clone the human mannose-binding lectin(MBL) gene and to express its recombinant protein in mouse liver tissue.Methods:After the human MBL cDNA was amplified by PCR and identified by sequencing and restriction mapping,it was inserted into eukaryotic expression vector pcDNA3.The recombinant plasmid pcDNA3-MBL was injected into mice in large quantity and large volume in a short time through tail vein.These mice were sacrificed 8 h after the injection.MBL were examined in serum and hepatic tissue with Western blot and immunohistochemistry.Results:After the human MBL gene was amplified and sequenced correctly,it was successfully inserted in the eukaryotic expression vector pcDNA3.Eight hours after the pcDNA3-MBL plasmid were injected into mice through tail veins,human MBL could be found both in serum and hepatic tissue with Western blot and immunohistochemistry examination.Conclusion:Systemic injection of pcDNA-MBL can result in human MBL protein expression in mice liver and secretion into blood.This result may provide a new idea to treat the congenital MBL insufficient patients,who have the predisposition of infectious diseases.

Objective　To investigate the changes of plasma epinephrine (E) and norepinephrine (NE) in rabbits with firearm thoracic wounds. 　Methods　 A total of 24 rabbits were divided into 3 groups randomly, the simple thoracic penetrating injury group (Group A, n = 8), the pseudo-injury group (Group B, n = 8)and the normal control group ( Group C, n = 8). The pressures of carotid artery and jugular vein were recorded by eight-road physiological recorder at 5 minutes before injury. And the concentrations of plasma E and NE were detected through high-performance liquid chromatography (HPLC) and electrochemical detection (ED) at 5 minutes, 30 minutes, 1 hour, 3 hours, 6 hours, 12 hours and 24 hours after injury in all the rabbits. 　Results　The concentrations of plasma E and NE in Group A were significantly higher than those of Group C (P<0.01) and changed regularly. There was no significant difference between Group B and Group C. The pressures of carotid artery and jugular vein of Group A increased by 1.8 and 6.8 times, respectively, during 2 millisecond after injury, then decreased to normal immediately. They decreased to the minimum (0.63 and 0.25 time, respectively) in 30 minutes and 5 minutes respectively and averagely, and raised to normal slowly after 6 hours and 12 hours respectively and averagely. There was no significant difference between Group B and Group C.　Conclusions 　 The concentrations of plasma E and NE increase significantly in the rabbits with thoracic firearm wounds. Their changes have close relationship with the severity of wound and can be used as a judging criterion during the early period of wound.

AIM: To investigate the molecular mechanisms of apoptosis and to elucidate the apoptosis signaling pathway triggered by etoposide in Jurkat human leukemia cells. METHODS: Apoptosis was detected using annexin V - FITC and propidium iodide (PI) staining, respectively, and annexin V - FITC positive cells and hypodiploid cells were analyzed by flow cytometry. Mitochondrial membrane potential (△Ψm) was detected using 3,3' - dihexyloxycarbocyanine iodide [ DiOC6 (3)] staining and △Ψm low cells were analyzed by flow cytometry. Preparation of cytosolic extracts and isolation of mitochondria were completed by centrifugation. Western blotting analysis was used to evaluate the level of cytochrome c, caspase - 3, and poly ( ADP - ribose) polymerase (PARP) expression. RESULTS: Etoposide induced apoptosis showing phosphatidylserine externalization and DNA fragmentation in a time - dependent manner and the apoptosis could be inhibited by a broad caspase inhibitor benzyloxycarbonyl - Val - Ala - Asp - fluoromethylketone ( zVAD. fmk). Collapse of △Ψm induced by etoposide preceded DNA fragmentation and phosphatidylserine externalization. In contrast, it was not blocked by zVAD. fmk. Etoposide caused cytochrome c release from mitochondria into cytosol, subsequent activation of caspase-3 (32 kD) presented with an intermediate (20 kD) and its active product (17kD), and cleavage of full- length PARP (116 kD) into the so- called apoptotic 85 kD fragment. CONCLUSION:Etoposide - induced Jurkat cell apoptosis is initiated through mitochondria signaling pathway with cytochrome c release into cytoplasm and caspase is the ultimate executioner of cell apoptosis.

Objective To investigate the effects of nuclear transcription factor- kappa B (NF-!B) and activated protein- 1 (AP- l) on rheumatic myocardial fibrosis. Methods Thirty rheumatic myocardial specimens and 10 normal samples were examined by Masson′s staining, immunohistochemical staining and image analy- sis. Results Both NF- !B and AP- 1 were expressed in the nuclei of myocardium with rheumatic heart disease (RHD). The degree of positive staining in myocardiurn with RHD was significantly correlated with the cardial collagen volume (NF-!B: r=0.8945, AP- 1: r=0.9011, P

This article discusses the material and methods of establishing tissue-engineered cardiac valve,the ethical problems of tissue engineered cardiac valve and the relationship between advanced technology and ethics.

Objective To establish a system to evaluate the mental workload on visual display interface in airplane cockpit after synthesizing three kinds of mental workload assessment techniques,i.e.main task measure method,physiology measure method and subjective evaluate method.Methods The evaluation indices of every kind of assessment techniques was defined,and the amount of each index through experiment and subjective inquiry was gained,weighted average was calculated and a quantification evaluation value of each kind of evaluation methods was got.At last,with weighted calculation of above three evaluation values,the evaluation value of mental workload on visual display interface in airplane cockpit was obtained.Results In M kinds of different designs of visual display interface in airplane cockpit,the synthetic evaluation value of one design was the smallest and the mental workload of this design was the smallest.The design of the smallest mental workload was chosen prior as the final scheme of visual display interface in airplane cockpit.Conclusion The evaluation system is combined with present main evaluation methods of mental workload and utilizes their advantages.The evaluating result can be quantified more directly and clearly.With this evaluation system,the mental workload can be evaluated during the design of visual display interface of airplane cockpit and the best scheme can be confirmed.

Objective To explore the clinical effect of continuous infusion of dopamine and furosemide on elderly patients with refractory heart failure.Methods 76 elderly patients with heart failure were selected as the observation subjects,they were randomly divided into observation group and control group,38 cases in each group.The control group was given oxygen inhalation,the expansion of vascular,cardiac and other conventional treatment.The observation group was given conventional treatment and continuous infusion of dopamine and furosemide.Clinical efficacy and cardiac function improvement were compared between the two groups.Restlts The effective rate of observation group was 92.1％,which was higher than that of the control group (73.7％) (x2 =10.29,P ＜ 0.05).After treatment,the improvement of cardiac function between the two groups had significant difference (t =15.94,10.18,all P ＜0.05).Conclusion Continuous infusion of dopamine and furosemide in treatment of elderly patients with refractory heart failure could improve heart function,enhance curative effect.

In the past ten years, 52 patients with double-chambered right ventricle (DCRV) were operated on in Xijing Hospital. They constituted 2.2% (52/1881) of all patients with congenital heart diseases. Of them, there were 32 males and 20 females, whose ages ranged from 4.5 to 30 years old. In one patient there was pure DCRV, and the remaining 51 patients DCRV was associated with other congenital cardiac anomalies, in which VSD was the most common (50), followed in order by pulmonary stenosis (6), aortic valve prolapse (4), atrial septal defect (2), and subaortic stenosis (1). The repair of DCRV and other intracardiac defects was done through the right ventricolotomy in 47 cases and through the right ventricolotomy plus atriotomy in 2 cases. In another 2 cases the operation was done via the right atriotomy and 1 case pulmonary arteriotomy, and only VSDs were closed, but DCRVs were missed. The major postoperative complications included cardiac arrhythmia (11) and low output syndrome (8). Three patients died, with the operative mortality of 5.8%. In this series, according to characteristics of the anomalous muscle bundle and its resulting obstruction, we divided 52 case DCRVs into two types: fibromuscular diaphragmatic type (24 cases, 44.7%) and muscular bundle-gap type (28 cases, 55.7%). In both types, there were not only hypertrophied anmalous muscle bundles on the septal side, but also hypertro-phied ventricoinfundibulum fold on the parietal side. In a few cases, the ventricoinfundibulum fold was more hypertrophic than the anomalous muscle bundle on the septal side.