Correlation analysis between physical activity and depressive tendencies among occupational groups: an isotemporal substitution approach.

OBJECTIVES: Sedentary behaviour (SB) and physical activity (PA) have been shown to be associated with depression. However, behaviours, such as PA, occupy a portion of an individual's 24-h day. Thus, an increase in time for one behaviour takes away time from another. Previous evidence suggests that it would be more appropriate to shift the focus to the importance of reallocating time spent in sedentary behaviour to time spent in physical activity. The aim of this study was to analyse the mutual replacement effect of different health behaviours on depressive tendencies by isotemporal substitution modelling (ISM) under the objective condition of considering a limited 24-h day. Second, we aimed to further explore the potential association between excessive or insufficient sleep duration and depressive symptoms. METHODS: A total of 10656 employees from 79 companies in four provinces of China participated in this survey. The Center for Epidemiological Studies Depression Scale (CES-D) was used to measure workers' depressive tendencies. The duration of various types of physical activity was self-reported by workers based on the International Physical Activity Questionnaire (IPAQ). ISM was used to assess the associations of time spent in different activities on displacement of equivalent time spent on other activities with depression risk. RESULTS: A total of 10656 participants (89.5% of the sample) were included in the analysis. The ISM found that a 30-min unit of SB replaced with walking (OR, 95% CI: 0.83, 0.77-0.88), sleep (≤ 8 h) (OR, 95% CI: 0.77, 0.74-0.79), moderate physical activity (MPA) (OR, 95% CI: 0.87, 0.81-0.93) and vigorous physical activity (VPA) (OR, 95% CI: 0.91, 0.84-0.99) was significantly and negatively associated with the risk of depressive tendencies. When sleep duration was less than 8 h, each additional half hour of sleep time was significantly associated with a lower risk of depressive tendencies, and this association was no longer significant after 8 h. CONCLUSION: Prolonged SB is common in the current workplace in China. Replacing an average of 30 min per day of SB with VPA and MPA, even walking is associated with less depression among workers. In addition, insufficient daily sleep is also an important risk factor for workers' depressive tendencies. These findings provide valuable evidence to promote mental health among occupational groups and support the development of healthy workplaces.

Transplantation of a beating heart: A first in man.

Background: In the current practice, graft ischaemia and reperfusion injury (IRI) is considered an inevitable component in organ transplantation, contributes to compromised organ quality, inferior graft survival and limitations in organ availability. Among all the donor organs, the heart is most vulnerable to IRI and the tolerated ischaemic time is the shortest. Methods: By combining adapted surgical techniques and normothermic machine perfusion (NMP), we performed the first case of ischaemia-free beating heart transplantation (IFBHT) in man. The donor heart was procured after an in situ NMP circuit was established, then underwent ex situ NMP and implanted under NMP support. The post-transplant graft function was monitored. Findings: The donor heart was procured, preserved, and implanted under a continuously perfused, normothermic, oxygenated, beating state. During ex situ NMP, the donor heart beat with sinus rhythm and adequate ventricular contraction, consumed oxygen and lactate, suggesting a good cardiac function. The dynamic electrocardiogram demonstrated an absence of ischaemic injury of the donor heart during the entire procedure. The echocardiogram showed an immediate graft function with a left ventricle ejection fraction (LVEF) of 70%. The patient was discharged on post-transplantation day 20 and was followed up for 8 months with normal cardiac function and life. Interpretation: This study shows the feasibility of IFBHT procedure, which might be able to completely avoid graft IRI, has thus the potential to improve transplant outcome while increasing organ utilization. Funding: This study was funded by National Natural Science Foundation of China, Guangdong Provincial Key Laboratory Construction Projection on Organ Donation and Transplant Immunology, and Guangdong Provincial International Cooperation Base of Science and Technology.

The multivariable prognostic models for severe complications after heart valve surgery.

BACKGROUND: To provide multivariable prognostic models for severe complications prediction after heart valve surgery, including low cardiac output syndrome (LCOS), acute kidney injury requiring hemodialysis (AKI-rH) and multiple organ dysfunction syndrome (MODS). METHODS: We developed multivariate logistic regression models to predict severe complications after heart valve surgery using 930 patients collected retrospectively from the first affiliated hospital of Sun Yat-Sen University from January 2014 to December 2015. The validation was conducted using a retrospective dataset of 713 patients from the same hospital from January 2016 to March 2017. We considered two kinds of prognostic models: the PRF models which were built by using the preoperative risk factors only, and the PIRF models which were built by using both of the preoperative and intraoperative risk factors. The least absolute shrinkage selector operator was used for developing the models. We assessed and compared the discriminative abilities for both of the PRF and PIRF models via the receiver operating characteristic (ROC) curve. RESULTS: Compared with the PRF models, the PIRF modes selected additional intraoperative factors, such as auxiliary cardiopulmonary bypass time and combined tricuspid valve replacement. Area under the ROC curves (AUCs) of PRF models for predicting LCOS, AKI-rH and MODS are 0.565 (0.466, 0.664), 0.688 (0.62, 0.757) and 0.657 (0.563, 0.751), respectively. As a comparison, the AUCs of the PIRF models for predicting LOCS, AKI-rH and MODS are 0.821 (0.747, 0.896), 0.78 (0.717, 0.843) and 0.774 (0.7, 0.847), respectively. CONCLUSIONS: Adding the intraoperative factors can increase the predictive power of the prognostic models for severe complications prediction after heart valve surgery.

Experience in the diagnosis and treatment of intravenous leiomyomatosis involving the inferior vena cava and/or right cardiac chambers.

OBJECTIVE: This study aimed to summarize our experience with the diagnosis and treatment of intravenous leiomyomatosis (IVL) involving the inferior vena cava (IVC) or right cardiac chambers. METHODS: This study retrospectively analyzed clinical data from 10 patients diagnosed with IVL involving the IVC or right cardiac chambers between May 2009 and October 2019 at one medical center. RESULTS: All patients were females aged 35 to 56 years (average, 46.8 years) with a history of uterine leiomyoma. Of these 10 patients, 8 manifested clinical symptoms and 2 were asymptomatic. Four were diagnosed with lesions involving the right cardiac chambers, four had lesions that extended into the suprahepatic IVC, and an additional two had lesions extending into the infrarenal IVC. All patients underwent surgery. Three of the four patients with extension into the right cardiac chambers underwent a two-stage operation, and an additional patient was managed with a one-stage operation. Patients who underwent a two-stage operation experienced less hemorrhaging and a shorter intensive care unit stay than the patient who underwent a one-stage operation. Six patients with intracaval extension alone underwent laparotomy, including four with a lesion extending into the suprahepatic IVC, under transesophageal echocardiography monitoring. Bilateral adnexectomy and ovariectomy were performed in seven patients, and unilateral adnexectomy and ovariectomy were performed in two patients; antiestrogen therapy was administered to two patients who retained a unilateral ovary and to one patient who retained bilateral ovaries. One patient suffered deep vein thrombosis in the left lower extremity after surgery that improved after treatment. All patients received conventional anticoagulant treatment postoperatively. All pathologic findings confirmed IVL, and the follow-up period ranged from 27 to 120 months (average, 57.5 months). Recurrence was not observed in the iliac vein or IVC, excluding one case of pelvic leiomyoma that recurred at one year postoperatively. CONCLUSIONS: IVL should be highly suspected when an IVC mass occurs in a patient with a history of uterine leiomyoma. Surgery is the gold standard treatment for IVL; a two-stage operation is more beneficial for patient recovery if the lesion exhibits intracardiac involvement, and transesophageal echocardiography is a helpful tool to monitor safety during surgical procedure for patients with a lesion invading the IVC above the level of the renal vein.

Crosstalk between the activated Slit2-Robo1 pathway and TGF-ß1 signalling promotes cardiac fibrosis.

AIMS: Previous reports indicated that the Slit2-Robo signalling pathway is involved in embryonic heart development and fibrosis in other solid organs, but its function in adult cardiac fibrosis has not been investigated. Here, we investigate the role of the Slit2-Robo1 signalling pathway in cardiac fibrosis. METHODS AND RESULTS: The right atrial tissue samples were obtained from patients with valvular heart disease complicated by atrial fibrillation during heart valve surgery and from healthy heart donors. The fibrotic animal model is created by performing transverse aortic constriction (TAC) surgery. The Robo1, Slit2, TGF-ß1, and collagen I expression levels in human and animal samples were evaluated by immunohistochemistry and western blot analysis. Echocardiography measured the changes in heart size and cardiac functions of animals. Angiotensin II (Ang II), Slit2-siRNA, TGF-ß1-siRNA, recombinant Slit2, and recombinant TGF-ß1 were transfected to cardiac fibroblasts (CFs) respectively to observe their effects on collagen I expression level. The right atrial appendage of patients with valvular heart disease complicated by atrial fibrillation found significantly up-regulated Slit2, Robo1, TGF-ß1, and collagen I expression levels. TAC surgery leads to heart enlargement, cardiac fibrosis, and up-regulation of Slit2, Robo1, TGF-ß1, and collagen I expression levels in animal model. Robo1 antagonist R5 and TGF-ß1 antagonist SB431542 suppressed cardiac fibrosis in TAC mice. Treatment with 100 nM Ang II in CFs caused significantly increased Slit2, Robo1, Smad2/3, TGF-ß1, collagen I, PI3K, and Akt expression levels. Transfecting Slit2-siRNA and TGF-ß1-siRNA, respectively, into rat CFs significantly down-regulated Smad2/3 and collagen I expression, inhibiting the effects of Ang II. Recombinant Slit2 activated the TGF-ß1/Smad signalling pathway in CFs and up-regulated Periostin, Robo1, and collagen I expression. CONCLUSIONS: The Slit2-Robo1 signalling pathway interfered with the TGF-ß1/Smad pathway and promoted cardiac fibrosis. Blockade of Slit2-Robo1 might be a new treatment for cardiac fibrosis.

Mid-Term Outcome after Tricuspid Valve Replacement.

OBJECTIVE: To evaluate the mid-term survival rate after tricuspid valve replacement (TVR). METHODS: We retrospectively studied 110 consecutive patients who underwent TVR from January 2007 to November 2017. A survival analysis was performed with the Kaplan-Meier method and the log-rank test. RESULTS: The median survival was 65.81 months. Mean age was 50 (range 39 to 59) years. Forty-eight patients (43.6%) were male, and 62 patients (56.4%) were female. Most of the patients (78.5%) were categorized into the New York Heart Association (NYHA) functional classes III/IV. Seventy-two patients (65.5%) had isolated TVR. Six-three patients (57.3%) had previously undergone heart surgery. The Kaplan-Meier survival rates at one year, three years, and five years were 59.0%±5%, 52.0%±6%, and 48.0%±6%, respectively. A Cox regression analysis demonstrated that the risk factors for mid-term mortality were advanced NYHA class (hazard ratio [HR] 2.430, 95% confidence interval [CI] 1.099-5.375, P=0.028), need for continuous renal replacement therapy (CRRT) treatment (HR 3.121, 95% CI 1.610-6.050, P=0.001), and need for intra-aortic balloon pump (IABP) treatment (HR 3.356, 95% CI 1.072-10.504, P=0.038). CONCLUSION: In TVR, impaired cardiac function before the operation and a need for CRRT or IABP treatment after the operation is independently associated with increased mid-term mortality.

Mid-term outcome after tricuspid valve replacement

Abstract Objective: To evaluate the mid-term survival rate after tricuspid valve replacement (TVR). Methods: We retrospectively studied 110 consecutive patients who underwent TVR from January 2007 to November 2017. A survival analysis was performed with the Kaplan-Meier method and the log-rank test. Results: The median survival was 65.81 months. Mean age was 50 (range 39 to 59) years. Forty-eight patients (43.6%) were male, and 62 patients (56.4%) were female. Most of the patients (78.5%) were categorized into the New York Heart Association (NYHA) functional classes III/IV. Seventy-two patients (65.5%) had isolated TVR. Six-three patients (57.3%) had previously undergone heart surgery. The Kaplan-Meier survival rates at one year, three years, and five years were 59.0%±5%, 52.0%±6%, and 48.0%±6%, respectively. A Cox regression analysis demonstrated that the risk factors for mid-term mortality were advanced NYHA class (hazard ratio [HR] 2.430, 95% confidence interval [CI] 1.099-5.375, P=0.028), need for continuous renal replacement therapy (CRRT) treatment (HR 3.121, 95% CI 1.610-6.050, P=0.001), and need for intra-aortic balloon pump (IABP) treatment (HR 3.356, 95% CI 1.072-10.504, P=0.038). Conclusion: In TVR, impaired cardiac function before the operation and a need for CRRT or IABP treatment after the operation is independently associated with increased mid-term mortality.

NLRP3 inflammasome-mediated pyroptosis contributes to the pathogenesis of non-ischemic dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is one of the most common causes of heart failure, and the underlying mechanism remains largely elusive. Here we investigated whether NLRP3 inflammasome-mediated pyroptosis contributes to non-ischemic DCM and dissected the underlying mechanism. We found that hyper activated NLRP3 inflammasome with pyroptotic cell death of cardiomyocytes were presented in the myocardial tissues of DCM patients, which were negatively correlated with cardiac function. Doxorubicin (Dox)-induced DCM characterization disclosed that NLRP3 inflammasome activation and pyroptosis occurred in Dox-treated heart tissues, but were very marginal in either NLRP3-/- or caspase-1-/- mice. Mechanistically, Dox enhanced expressions of NOX1 and NOX4 and induced mitochondrial fission through dynamin-related protein 1 (Drp1) activation, leading to NLRP3 inflammasome-mediated pyroptosis in cardiomyocytes via caspase-1-dependent manner. Conversely, both inhibitions of NOX1 and NOX4 and Drp1 suppressed Dox-induced NLPR3 inflammasome activation and pyroptosis. The alterations of NOX1 and NOX4 expression, Drp1 phosphorylation and mitochondrial fission were validated in DCM patients and mice. Importantly, Dox-induced Drp1-mediated mitochondrial fission and the consequent NLRP3 inflammasome activation and pyroptosis were reversed by NOX1 and NOX4 inhibition in mice. This study demonstrates for the first time that cardiomyocyte pyroptosis triggered by NLRP3 inflammasome activation via caspase-1 causally contributes to myocardial dysfunction progression and DCM pathogenesis.

Genotype-Guided Warfarin Dosing in Patients With Mechanical Valves: A Randomized Controlled Trial.

BACKGROUND: The clinical utility of genotype-guided warfarin dosing remains controversial. The objective of this trial was to evaluate the efficacy and safety of genotype-guided warfarin dosing in East Asians. METHODS: A double-blind, randomized control trial was performed to compare a genotype-guided dosing algorithm (CYP2C9, VKORC1, and CYP4F2) with a clinical-guided one in the initiation treatment for patients with mechanical heart valves. The primary outcomes included the time to reach a stable dose and the percentage of time in the therapeutic range (TTR). RESULTS: Two hundred one patients were randomly assigned to treatment, 101 to control and 100 to study. The major bleeding and thromboembolic event-free rate in the study group was 97.0% (95% confidence interval: 90.9% to 99.2%). Compared with the control group, the study group shortened the time to reach a stable dose (mean: 42.09 ± 23.655 days versus 33.52 ± 20.044 days, p = 0.009). The TTRs were 47.257% and 47.461% in the control and study group (p = 0.941), respectively. Patients with the CYP2C9 *1/*3 genotype had higher international normalized ratio (INR) variability than patients with the CYP2C9 *1/*1 genotype (p = 0.024). Compared with normal and sensitive responders, the highly sensitive responders were at increased risk of an INR of 4.0 or greater (p < 0.05). CONCLUSIONS: The genotype-guided warfarin dosing was safe and might be more efficient for the time to reach a stable dose. Pharmacogenomic testing might be beneficial to identify the patients with the CYP2C9 *1/*3 genotype and the highly sensitive responders, who were in the high-risk subgroup of patients with mechanical heart valves. An appropriately powered study is needed to further confirm these findings.

The role of ß-adrenergic receptors and p38MAPK signaling pathways in physiological processes of cardiosphere-derived cells.

The effects of ß adrenergic receptors (ß-ARs) and p38 mitogen-activated protein kinases (MAPK) pathways on cardiosphere-derived cells (CDCs) are largely unknown. This study aimed to investigate the roles of ß-ARs and p38MAPK pathways on the proliferation, apoptosis, and differentiation capacity of CDCs. The CDCs were treated with ß1-AR blocker (Met group), ß2-AR antagonist (ICI group), and p38MAPK inhibitor (SB group), non-selective ß-AR blocker (PRO group), and ß-AR agonist (ISO group). The viability, apoptotic rate and differentiation status of CDCs were determined by MST-1 assay, flow cytometery, and Western blot, respectively. The CDCs viability significantly reduced in ICI group (all P < 0.05), and SB group had a significant high viability after 48 h treatment (P < 0.05). Compared with control group, all treated groups had a low apoptotic rate. After treatment for 72 h, ISO treatment elevated the expression of Nkx2.5, and could partially or fully attenuate the inhibitory effects of ß-AR antagonists and/or p38MAPK inhibitor. A similar overall trend of protein expression levels among all groups could be observed between protein pairs of cTnT and ß1-AR as well as c-Kit and ß2-AR, respectively. These results suggested that ß-ARs and p38MAPK signaling pathways play crucial roles in the proliferation and differentiation of CDCs. Our findings should be helpful for better understanding the molecular mechanism underlying the physiological processes of CDCs.

A comparative study of the influence of two types of PHEMA stents on the differentiation of ASCs to myocardial cells.

In the present study, subcutaneous fat was obtained from adult women that had undergone conventional liposuction surgery. A comparative study was performed to investigate the effect of transparent and white poly­ß­hydroxyethyl methacrylate (PHEMA) stents, which have different surface and cross­sectional morphological characteristics, on the differentiation of adipose­derived stem cells (ASCs) into myocardial cells. The cell counting kit­8 assay revealed that cell growth increased at varying rates among the different treatment groups. The absorbance of the experimental transparent PHEMA treated group increased in a time­dependent manner with the duration of incubation. The highest levels of proliferation were observed in the transparent PHEMA group. In addition, the transparent PHEMA treated group exhibited the strongest cell adhesion ability, which was significantly different to that of the white PHEMA group (P<0.01 and P<0.05 for Matrigel and fibronectin assay, respectively). Comparisons between the two stent materials with the inducer control group revealed statistically significant differences in the rate of ASC differentiation (P<0.05). The level of differentiation was the greatest in the transparent PHEMA group, and was significantly different to the white PHEMA group (P<0.05) and the blank control group (P<0.01). The results suggest that the inducers 5-aza-2-deoxycytidin and laminin, and material microstructure stents effectively promote the proliferation, growth and adhesion of ASCs. However, the transparent material microstructure may be a more suitable candidate for ASC­associated injections. The present study provides further evidence that a PHEMA stent structure, comprised of a high number of matrixes and a low water content, induces a high level of ASC differentiation to myocardial cells.

Downregulation of miR-101 contributes to epithelial-mesenchymal transition in cisplatin resistance of NSCLC cells by targeting ROCK2.

Chemoresistance and epithelial-mesenchymal transition (EMT) in cancer are linked phenomena. EMT contributes to chemoresistance, however, little is known about whether chemotherapy can induce EMT in cancer cells. Here, we found that miR-101 expression was downregulated in cisplatin-resistant non-small cell lung cancer (NSCLC) cells. Restoration of miR-101 expression inhibited EMT and increased the sensitivity of cisplatin-resistant NSCLC cells to cisplatin in vitro by targeting ROCK2. Furthermore, ROCK2 protein level was inversely correlated with miR-101 level in NSCLC tissue samples. Kaplan-Meier analysis revealed that low miR-101 expression in NSCLC was correlated with poor survival time. In summary, our results provide novel mechanistic insights into the role of miR-101/ROCK2 signaling in the cisplatin resistance of NSCLC cells. Targeting of miR-101 is a potential therapeutic approach for NSCLC.

In vitro hemocompatibility evaluation of poly (4-hydroxybutyrate) scaffold.

The biosynthetic thermoplastic poly-4-hydroxybutyrate (P4HB) possesses favorable tensile strength and elongation performance and has been studied as a new implantable polymer material for medical uses. However, its hemocompatibility has not been tested to confirm its applicability to tissue engineering. In this study, a series of experiments was performed that included erythrocyte hemolysis tests, dynamic blood coagulation tests, platelet adhesion tests, effects on blood coagulation, Wright staining, and adsorption of erythrocytes, leukocytes, platelets, and plasma proteins. The results were compared with control tests on polyvinyl chloride (PVC), a biomaterial in current use, to evaluate the relative in vitro hemocompatibility of P4HB. The degree of hemolysis in the presence of P4HB was 1.9 ± 0.2%. The absorbance-time curve for blood clotting declined slowly and smoothly. There were no differences in the test values of Factor XII, activated partial thromboplastin time (APTT), or fibrin degradation products (FDPs) among whole blood samples exposed to P4HB or PVC and the blank control groups (P > .05). Adsorption of platelets and globulin was similar in samples exposed to P4HB and PVC (P > .05), but the adsorption of erythrocytes, leukocytes, and albumin to P4HB was higher (P < .05). In conclusion, P4HB compares favorably with PVC in terms of blood compatibility, except for a higher affinity for erythrocytes and leukocytes. The findings indicate that P4HB, an alternate scaffolding material with advantageous properties, is generally acceptable for bioengineering use.

Effect of high porosity on biodegradation of poly (4-hydroxybutyrate) in vivo.

Poly-4-hydroxybutyrate, P(4HB), is a biosynthetic thermoplastic polymer that has been studied as a bio-absorbable medical material. In order to explore the in vivo biodegradation behaviour of porous P(4HB) membranes with specified apertures (89-150 µm), membranes with different porosities were implanted subcutaneously into the backs of 27 eight-week-old Sprague Dawley® rats. The implanted specimens were examined with Masson and hematoxylin and eosin staining. Masson staining indicated that the P(4HB) membranes were encased in fibrous cysts and that more collagen fibers were present within the sections of the hyper-porosity group. Hematoxylin and eosin staining showed that the residual area of the P(4HB) membranes in the hyper-porosity group decreased sharply compared to the hypo-porosity group, which implied that the P(4HB) membranes with higher porosity degraded faster than those with lower porosity. A slow degradation phase persisted for approximately 14 weeks during the degradation process. After the 16th week, the P(4HB) scaffolds fell into a fast degradation phase. The residual areas of the hyper-porosity P(4HB) membranes at the 32nd week were reduced by 39.76% compared with the second week after implantation. We concluded that P(4HB) membranes manifest a special biodegradation behavior in vivo and that the increased porosity of these membranes is an important factor favoring their biodegradation rates.

Inflammatory pseudotumor of the right ventricle in a 35-year-old woman with Behçet's disease: a case report.

Inflammatory pseudotumor is a rare benign neoplasm. It is common in children and has been reported in various locations throughout the body but rarely in the heart. Behçet's disease is a multisystemic, recurrent, inflammatory disorder. We report a 35-year-old Behçet's disease patient with pseudotumor of the right ventricle and multiple pulmonary emboli. Transthoracic echocardiography showed dilation of right atrium, right ventricle, and a mass in the right ventricle. Multislice computed tomography revealed a large, poorly defined mass infiltrating the groove and multiple pulmonary emboli. Surgery was performed with diagnostic and therapeutic intent. Following sternotomy, we identified a mass in the anterior wall of right ventricle, the outflow tract, and the inflow tract of right ventricle. The histopathologic analysis identified an inflammatory infiltrate composed of lymphocytes, plasma cells, and other inflammatory cells, without mitosis. And there were also some thrombus on top of the mass.

[Test of carotid artery replacement by polyurethane artificial vascular graft with recombinant fibrinolytic enzyme factor II-modified lumina in dogs].

OBJECTIVE: To evaluate the implantation effect of artificial vascular grafts with recombinant fibrinolytic enzyme factor II (rF II)-immobilized lumina in animal test. METHODS: Four mm internal diameter (ID) polyurethane (PU) artificial vascular grafts were prepared by dipping and leaching method. The micro-pore size and morphology of the graft walls were observed by SEM. The graft lumina were immobilized with rF II. Twenty hybrid male dogs [weighing (20 +/- 1) kg] were used for animal model of carotid artery defect and were randomly divided into 3 groups: rF II -immobilized PU group, no rF II -immobilized PU group and expanded polytetrafluoroethylene (ePTFE) group. The vascular grafts were implanted for repairing injured segments of carotid artery in dogs. The general health state of animals was recorded. At 30 days and 60 days, the patency rate of every group was calculated. At 60 days IDs were measured, cell proliferation in neointima was inspected by light microscope, morphology on neointima was observed by SEM. RESULTS: The ID of the PU vascular grafts was (3.74 +/- 0.06) mm, wall thickness was 0.4-0.6 mm, the wall density was 0.25 g/cm3, the porosity was 79.8%, racial compliance was 8.57%/100 mmHg. In the wall, micropores were well distributed and opened-pores structure was observed. Pore size was (140 +/- 41) microm in the outside layer, pore size was (100 +/- 3) microm in the inside layer, thickness ratio of outside / inside layers was 2 : 1, the pore size was (40 +/- 16) microm on the lumina surface. After operation the wounds on neck healed, all the animals survived and had no complication. At 30 days and 60 days after implantation, the patency rate for rF II -immobilized PU group were 100% and 66.7%, for no rF II -immobilized PU group were 66.7% and 33.3%, and for ePTFE group were 67.7% and 0 respectively, but at 60 days there were thrombosis at anastomotic sites of some grafts occluded. Before operation the IDs for rF II-immobilized PU group, no rF II -immobilized PU group and ePTFE group were (3.74 +/- 0.06), (3.74 +/- 0.06) and (4.00 +/- 0.03) mm, at 60 days after operation the IDs were (4.51 +/- 0.05), (4.31 +/- 0.24) and (4.43 +/- 0.12) mm respectively, showing no statistically significant differences between 3 groups (P > 0.05). Histological inspection indicated that at 15 days a layer of plasma protein deposited on the lumina, at 30 days some cells adhered to the lumina, at 60 days neointima could be observed on the lumina. Thickness of the neointima became larger with implantation time. At 60 days neointima thickness at proximal end, middle site and distal end of graft were (560 +/- 22), (78 +/- 5) and (323 +/- 31) microm respectively for rF II -immobilized PU group. The results of SEM showed that neointima surface consisted of flat and long cells which long axes ranged with blood flow direction and was similar to lumina morphology of carotid artery of dog. CONCLUSION: Immobilization of rF II to lumina of grafts could enhance fibrinolytic activity and inhibited formation of thrombo-embolic which led to an increase in patency rate after implantation.

Late pulmonary valve implantation after repair of tetralogy of Fallot.

Ten cases of elective late pulmonary valve implantation after repair of tetralogy of Fallot were reviewed. The interval after initial repair ranged from 1.5 to 43 years (mean, 20.0 +/- 12.3 years). There was no hospital mortality or late death during a mean follow-up of 12.5 months. Preoperatively, 9 patients were in New York Heart Association functional class III-IV; after pulmonary valve implantation, all 10 patients were in class I-II (average improvement, 1.7 classes). Left ventricular ejection fraction improved significantly (from 62.1% +/- 4.7% to 70.2% +/- 4.9%), as did fractional shortening (from 34.0% +/- 5.0% to 40.0% +/- 4.2%). Right ventricular diameter decreased significantly (from 32.3 +/- 7.5 to 24.4 +/- 5.4 mm). QRS duration decreased significantly (155.2 +/- 27.1 vs. 140.0 +/- 21.2 msec), but there was no significant difference in QT interval (460.9 +/- 29.6 vs. 451.9 +/- 50.6 msec). Hospital stay was 4-7 days. One patient had preoperative ventricular fibrillation requiring resuscitation and an implantable cardiac defibrillator; another needed a defibrillator at the time of pulmonary valve implantation, because of ventricular arrhythmias. It was concluded that late pulmonary valve implantation after tetralogy of Fallot repair had significant benefits and carried low operative risk.