Chun-Che Shih

National Yang Ming University, T’ai-pei, Taipei, Taiwan

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Publications (78)149.21 Total impact

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    ABSTRACT: In congestive heart failure the balance between cell death and cell survival in cardiomyocytes is compromised. Sirtuin 1 (Sirt1) activates cell survival machinery and has been shown to be protective against ischemia/reperfusion injury in murine heart. The role of Sirt1 in heart failure, especially in human hearts is not clear.
    Journal of biomedical science. 06/2014; 21(1):57.
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    ABSTRACT: In this study, we assessed the association between the tortuosity of the thoracic aorta as measured by the reporting standards for thoracic endovascular aortic repair (TEVAR), described by the Society for Vascular Surgery, and midterm outcomes after TEVAR for atherosclerotic aneurysms. We analyzed 77 consecutive patients who underwent TEVAR for atherosclerotic aneurysms from November 2006 through May 2013 in a single institution. The preoperative aortic tortuosity index (TI) was calculated by computed tomography aortography, and patients were divided into low-tortuosity (TI ≤ 1.29) and high-tortuosity (TI > 1.29) groups. The relationships between TI and the occurrence of endoleaks, complications, and survival were analyzed. The mean follow-up period was 29 ± 26 months. During this period, endoleaks occurred in 19 patients. Patients in the high-tortuosity group were at greater risk for endoleaks (odds ratio, 9.95; 95% confidence interval, 2.06-48.1; P = .004) and stroke (odds ratio, 13.2; 95% confidence interval, 1.03-169; P = .047) than those in the low-tortuosity group. The overall survival at 1, 3, and 5 years was 73%, 69%, and 63%, respectively, for the high-tortuosity group and 92%, 92%, and 86%, respectively, for the low tortuosity group. Our findings demonstrated that high tortuosity of the thoracic aorta is associated with higher rates of endoleaks and lower survival in patients undergoing TEVAR for atherosclerotic aneurysms. Patients with aneurysms in a highly tortuous aorta may therefore need greater attention in preoperative planning, perioperative procedures, and follow-up examinations.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 05/2014; · 3.52 Impact Factor
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    ABSTRACT: Hyperphosphatemia-induced endothelial dysfunction has been shown to play a pathogenic role in the development of atherosclerosis in chronic kidney disease (CKD) through unclear mechanisms. Emerging evidence indicates that autophagy is involved in the maintenance of normal cardiovascular function. However, it is unclear whether autophagy participates in the molecular mechanism underlying high phosphate (Pi)-induced endothelial dysfunction. The autophagy activity was determined by the immunofluorescence staining of the expression of endothelial microtubule-associated protein 1 light chain 3 (LC3) in the 5/6 nephrectomy rat model of CKD and sham-operated control rats. The LC3-II/LC3-I ratio and the activation of the Akt/mammalian target of rapamycin (mTOR) signaling pathway were determined in cultured human microvascular endothelial cell (HMEC-1) endothelial cells that were exposed to a high concentration of Pi with or without the Pi influx blocker phosphonoformic acid, the autophagy inhibitor 3-methyladenine, and the autophagy inducer rapamycin. The impacts of autophagy on Pi-induced apoptotic damage were assessed by flow cytometry. The in vivo rat model of CKD revealed that hyperphosphatemia is associated with increased endothelial LC3 staining. The exposure of HMEC-1 cells to high Pi induced both dose-dependent and time-dependent increases in the LC3-II/LC3-I expression ratio accompanied by the inhibition of the Akt/mTOR signaling pathway. In HMEC-1 cells, high Pi-induced autophagy and the inhibition of Akt/mTOR signaling were reversed by phosphonoformic acid through the blockage of Pi influx. Apoptosis, characterized by the levels of cleaved caspase 3 and poly(ADP-ribose) polymerase, along with autophagy was induced by high Pi, and the inhibition of autophagy by 3-methyladenine significantly aggravated high Pi-induced apoptosis. The flow cytometry results confirmed that the blockage of autophagy promoted the apoptosis of endothelial cells. Hyperphosphatemia induces endothelial autophagy, possibly through the inhibition of the Akt/mTOR signaling pathway, which may play a protective role against high Pi-induced apoptosis.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 05/2014; · 3.52 Impact Factor
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    ABSTRACT: Background/Purpose Monocytes play important roles in inflammatory responses and vascular remodeling after vascular stenting. This research focused on impacts of nickel (Ni) ions released from a corroded cardiovascular stent on cytotoxicity and monocyte activation. Methods A human promonocytic (macrophage-like) cell line (U937) was exposed to graduated concentrations of Ni2+in vitro. Cells were observed and harvested at indicated times to determine the effects using histological and biochemical methods. Results Ni caused U937 cell death in dose- and time-dependent manners. In vitro, high concentrations of Ni2+ (>240 μM) significantly induced cell apoptosis and increased terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL)-positive cells according to flow cytometric surveillance and triggered apoptotic cell death. Although no significant changes in Bcl-2 or Bax expressions were detected after 24 hours of Ni2+ treatment, increasing cleavage of caspase-3 and -8 was present. Results showed that cleavage of caspase-8 was inhibited by the presence of the inhibitor, Z-IETD-FMK, and this suggested the presence of Ni2+-induced U937 cell death through a death receptor-mediated pathway. Simultaneously, when treated with a high concentration of Ni2+ ions, expressions of the vascular remodeling factors, matrix metalloproteinases (MMP)-9 and -2, were activated in dose- and time-dependent manners. Secretion of the proliferative factor, monocyte chemoattractant protein (MCP)-1, significantly increased during the first 6 hours of incubation with 480 μM Ni2+-treated medium. Conclusion Our results demonstrated that a high concentration of Ni ions causes apoptotic cell death of circulating monocytes. They may also play different roles in vascular remodeling during the corrosion process following implantation of Ni alloy-containing devices.
    Journal of the Formosan Medical Association. 01/2014;
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    ABSTRACT: Structural changes and incomplete endograft apposition to the aortic arch (bird-beak configuration) after thoracic endovascular aortic repair are poorly understood. The aim of this study was to analyze the morphologic changes, conformability, and angulation factors in patients who underwent stainless steel-based stent graft repair of thoracic aortic pathology. From March 2011 to March 2012, the study enrolled 19 patients with aortic pathology requiring proximal fixation in zones 2 and 3 who underwent stent graft repair using Zenith Pro-Form TX2 stent grafts (Cook Medical, Bloomington, Ind). For comparison, another 19 patients who received Zenith Z-Trak stent grafts were selected from December 2009 to February 2011. Chest computed tomography scans were analyzed at baseline, and then at 1, 6, and 12 months postoperatively. Arch angulation and bird-beak configuration were evaluated according to sealing zones of attachment by Aquarius iNtuition software (TeraRecon, San Mateo, Calif). The treated diseases included chronic type B aortic dissection in 17 patients and degenerative aneurysms in 21. Significant arch angle transformation was noted at the zone 2 level between the Pro-Form and Z-Trak treated groups (150° ± 11° vs 158° ± 6°; P = .033) and left subclavian artery level (152° ± 12° vs 160° ± 8°; P = .031) during 1 year of follow-up. The bird-beak configuration was detected in six patients (32%) in the Pro-Form group and in 11 (58%) in the Z-Trak group (P = .096) at 1 month, and in six (32%) in the Pro-Form group and in 14 (74%) in the Z-Trak group (P = .022) at 12 months. The mean bird-beak angle was significantly less in Pro-Form-treated patients at 1 month (5° ± 9° vs 15° ± 13°; P = .019) and at 1 year (6° ± 10° vs 18° ± 15°; P = .033). In the Pro-Form platform, a preoperative zone 2 angle <151.1° was a better estimation of the presence of a postoperative bird-beak configuration, with a sensitivity of 86% and specificity of 83%. Aortic remodeling after stainless steel stent graft repair of thoracic aortic pathology is a continuous process. Significant arch angle transformation was discovered over the zone 2 and left subclavian artery levels. TX2 Pro-Form stent grafts improved arch conformation after 1 year of follow-up. Furthermore, in the patients with dissection, a preoperative distal arch angle of zone 2 was predictive of postoperative bird-beak configuration, regardless of whether they were treated with a Pro-Form stent graft.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 10/2013; · 3.52 Impact Factor
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    ABSTRACT: Aortic valve replacement (AVR) remains the gold standard treatment for symptomatic severe aortic stenosis (AS). For the past 10 years, transcatheter aortic valve implantation (TAVI) has been applied in patients with high surgical mortality and morbidity risks. The preliminary results of our TAVI patients are presented in this study. Ten high-risk patients with severe AS, for AVR, were referred and accepted for TAVI in the 6 month period from May 2010 to October 2010. The patient age, logistic EuroSCORE, femoral arterial diameter, aorta annulus size, aorta valve area (AVA), mean aortic pressure gradient (MPG), as well as coronary angiography results were all collected. Six patients were treated via the transapical approach in March 2010, whereas the other four were treated with the transfemoral approach, according to their femoral artery diameter and arterial quality. This study focuses on the immediate, 1 month, 3 month, and 1 year results of TAVI. The average age of the 10 patients receiving TAVI was 81.5 years. The mean calculated EuroSCORE was 28.3 ± 7.9%. The mean AVA was 0.61 ± 0.19 cm(2). The MPG was 48 ± 16 mmHg. The surgical technical success achieved 100%. There was no reported moderate to severe postoperative paravalvular aortic regurgitation, permanent complete atrioventricular block, major access site complication, or embolic stroke. Chronic renal failure, which necessitated permanent hemodialysis, developed in 10% of the patients. One acute myocardial infarction and one case of pneumonia developed postoperatively. The AVA was increased by 251%, whereas the MPG was decreased by 80% at the 3 month follow-up. The 30-day mortality rate was 10%. The all-cause 1-year mortality rate was 20%. This new technique and device requires greater caution and needs more practice to accumulate sufficient experience. The studied patients were very fragile, due to old age and multiple comorbidities. Our results are similar to findings of multicenter trials. With careful patient screening and selection, TAVI can be a promising treatment for high-risk severe AS patients.
    Journal of the Chinese Medical Association 09/2013; · 0.75 Impact Factor
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    ABSTRACT: Background:The use of endovascular aneurysm repair (EVAR) as a treatment for abdominal aortic aneurysm (AAA) has started to become popular in Taiwan. Quality of life is considered an indicator of clinical outcome, and self-management and health literacy have been identified as significant contributors to quality of life. However, the research on these three variables, and relationships among them in AAA patients who have undergone EVAR, is limited.Aims:The purpose of this study is to examine the relationship between self-management, health literacy and quality of life in AAA patients who have undergone EVAR in Taiwan.Methods:This study uses a cross-sectional design with convenience sampling. A total of 105 patients were sampled in the outpatient clinic when they returned for a follow-up visit to a veterans' general hospital in Taiwan between May 2011 and June 2012. Four questionnaires (demographic, self-management, health literacy, quality of life) were used to collect data. Regarding the relationship among these variables, Pearson correlations and hierarchical logistic regression were used to analyze the relationship.Results:Self-management has a 73% mediation effect and an indirect effect of 13.51 on the relationship between health literacy and quality of life, while education and exercise habit has a 57% mediation effect and an indirect effect of 6.20 on this same relationship.Conclusion:These findings can be used to identify specific populations who have more risk for worse outcomes. They can then be provided with education to promote exercise behavior and to enhance self-management to achieve better quality of life.
    European Journal of Cardiovascular Nursing 09/2013; · 2.04 Impact Factor
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    ABSTRACT: The purpose of the present study was to examine the effects of surgeon elective abdominal aortic aneurysm repair volume on outcomes after ruptured abdominal aortic aneurysm (rAAA) repair. A nationwide claims database was used to identify patients who underwent rAAA repair from 1998 to 2009. Surgeon elective open abdominal aortic aneurysm repair (EAR) volume was classified as low, medium, or high. Associations between surgeon EAR volume and in-hospital mortality, overall survival, and complications after open rAAA repair (RAR) were compared with multivariate analysis. Associations between surgeon elective endovascular abdominal aortic aneurysm repair (EER) volume and outcomes after endovascular rAAA repair (RER) were also analyzed. A total of 537 patients who underwent rAAA repair were identified, including 498 who underwent RAR and 39 who underwent RER. In-hospital mortality rates after RAR were 49, 38, and 24 % in the low, medium, and high EAR volume groups, respectively (p < 0.001). Patients in the low surgeon EAR volume group had higher in-hospital mortality than those in the high surgeon EAR volume group [odds ratio 3.39, 95 % confidence interval (CI) 1.52, 7.59; p = 0.003]. Patients in the low surgeon EAR volume group also had higher long-term mortality (hazard ratio 1.86, 95 % CI 1.21, 2.85; p = 0.005). There were no significant differences in complication rates among the surgeon EAR volume groups or in-hospital mortality after RER among the surgeon EER volume groups. Surgeon EAR volume is associated with in-hospital mortality and long-term survival after RAR.
    World Journal of Surgery 07/2013; · 2.23 Impact Factor
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    ABSTRACT: BACKGROUND: Deep vein thrombosis (DVT) is a potentially progressive disease with complex clinical sequelae. The clinical practice guidelines of the American College of Chest Physicians (ACCP) recommend various treatments for all patients with objectively proven DVT. This study retrospectively compares enoxaparin with CDT on treatment efficacy and safety and the evolution of acute proximal DVT in the lower limbs. METHODS: This study comprised 53 patients with acute proximal DVT, who received either CDT followed by intravenous unfractionated heparin (UFH) or adjusted subcutaneous low-molecular-weight heparin (LMWH) (enoxaparin) for 7-14 days. Warfarin was administered to all patients for at least 6 months. The study endpoints included the evolution of DVT and treatment efficacy and safety, which were assessed with frequent duplex ultrasounds, plethysmography, and venography. The mean duration of the follow-up was 15.2 months. RESULTS: In the CDT group, patency of the iliofemoral vein segment was observed in 42.3% of the patients after 1 week (p < 0.001) and in 69.2% after 6 months. In the control group, patency was present in 15.4% of the patients after 3 months and in 38.5% after 6 months (p = 0.05). Femoral venous obstruction was found in 30.8% of CDT patients and in 61.5% of the control group (p = 0.05). Furthermore, femoral venous insufficiency was present in 46.2% of the CDT group and 53.9% of the control group after 6 months (p = 0.587). After 12 months, post-thrombotic syndrome (PTS) was found in 19.2% of the CDT patients compared to 50% of the LMWH group (p = 0.04). CONCLUSION: Duplex ultrasound analysis of thrombus progression is useful for assessing the treatment of a patient with acute proximal DVT. In this study, patients undergoing CDT experienced higher thrombus resolution and early recanalization of their veins, which may preserve venous function and further prevent development of post-thrombotic syndrome.
    Journal of the Chinese Medical Association 05/2013; 76(5):265-270. · 0.75 Impact Factor
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    ABSTRACT: Nutcracker syndrome (NCS) is a rare pathology manifested by pain or hematuria in males and females alike. It can be easily overlooked, and should be considered in young men or women with symptoms of extended duration. We present a case of a 54-year-old female with chronic lower abdominal pain radiating to the left thigh of 4 years in duration. Computed tomography (CT) eventually revealed engorged left renal, gonadal, and uterine veins due to compression between the superior mesenteric artery (SMA) and the abdominal aorta, consistent with NCS. After a successful endovascular stenting and a 6-month period of antiplatelet and anticoagulant therapy, the patient returned to stable health. NCS, while rare, should be suspected in patients of both sexes with persistent pain or hematuria.
    Journal of the Chinese Medical Association 04/2013; · 0.75 Impact Factor
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    ABSTRACT: Takayasu's arteritis (TA) is a chronic inflammatory disease that involves the aorta and its major branches; however, only limited data are available on TA in Taiwan. This study presents the clinical features, angiographic findings, and response to treatment of patients with TA at a single institute in Taiwan. A search of the hospital database for ICD9 code 446.7 (Takayasu's disease) between 1990 and 2010 was performed. Seven cases fulfilled the 1990 American College of Rheumatology diagnostic criteria for Takayasu's disease. Angiographic classification was made according to the guidelines of the 1994 International TA Conference in Tokyo. All of our cases were female, and the median age at diagnosis was 27.5 years (range 14-36 years). Four patients had an angiographic classification of type I (57.1%), two were classified as type V (28.6%), and one was classified as type III (14.3%). The most common symptoms/signs were dizziness and vascular bruits. Two patients underwent bypass surgery, four endovascular stenting, and one hybrid bypass with stenting. After a mean follow-up period of 50.3 ± 68.2 months (range 12.3-199.6 months), both the procedure success and survival rates were 100%. There were four restenosis cases (57.1%), one in the surgical bypass group without symptoms (33.3%), and three in the endovascular group (60%), five restenosis in 14 stents (35.7%). Also, these three patients received secondary endovascular procedure for percutaneous transluminal angioplasty or restenting. There have not been any case series reports about treatments of Takayasu's disease in Taiwan to date, based on a search of the PubMed/MEDLINE and Cochrane Library databases. Although endovascular treatment is becoming more prevalent, the restenosis rate is still high, and long-term follow-up and further strategy for restenosis management are the main challenges.
    Journal of the Chinese Medical Association 02/2013; 76(2):83-7. · 0.75 Impact Factor
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    ABSTRACT: The Bentall operation is recommended for thoracic aortic dissection or aneurysm involving the aortic root. However, if the lesion extends to the aortic arch, concomitant Bentall operation plus aortic arch replacement (CoBAAR) surgery is required. CoBAAR is challenging because of its complex cardiopulmonary procedure, prolonged cardiopulmonary bypass time, and demanding operative techniques. Therefore, surgical mortality and morbidity rates for CoBAAR are very high. However, the Bentall operation performed as a single procedure may lead to reoperation if the residual aneurysm progresses. Therefore, CoBAAR as a one-stage surgery can lower the need for reoperation and possible further complications. Nine patients received CoBAAR during January 2005 to May 2010. Six patients were diagnosed with Sanford type A aortic dissection and three with nondissecting ascending aortic and arch aneurysm. Four patients received a Bentall operation plus hemiarch replacement. The others received a Bentall operation plus total arch replacement along with elephant trunk because of extensive lesions. The in-hospital mortality was 11.1% (1 patient with total arch replacement). Morbidity included stroke (2 patients), spinal cord injury (1 patient), mechanical ventilation for more than 72 hours (5 patients), and temporary renal dialysis (3 patients). Eight patients survived. CoBAAR is a demanding operative technique requiring complex cardiopulmonary bypass. However, surgeons can perform this procedure on extensive ascending aortic dissection or aneurysm patients, achieving satisfactory results.
    Journal of the Chinese Medical Association 02/2013; 76(2):88-94. · 0.75 Impact Factor
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    ABSTRACT: PURPOSE: Percutaneous tracheostomy (PT) has gained worldwide acceptance as a bedside procedure by intensivists, but its popularity has declined based on reports of some relative contraindications. The aim of this study was to ascertain the perioperative comorbidities of PT when it is performed by surgeons with experience performing standard tracheostomy. METHODS: Prospective data were collected and analyzed for consecutive PTs performed in intensive care units. RESULTS: No procedure-related mortality occurred in the present study. No significant differences in perioperative comorbidities, such as transient hemodynamic instability and postoperative wound infection, were noted between the relative contraindication (RC) and normal condition (NC) groups. Otherwise, instrument failure (5 cases, p = 0.052) and procedure failure (2 cases, p = 0.222) occurred in the RC group, but not in the NC group. Two patients in the NC group and one patient in the RC group needed to undergo a reoperation to check for bleeding. In a subgroup analysis, more bleeding events were noted for the patients with coagulopathy (p = 0.057), and premature extubation of the endotracheal tube/instrument failure (p = 0.073) was more common in the patients with neck anatomical difficulty in the RC group. CONCLUSIONS: For patients with relative contraindications, the potential of using PT should be determined on an individual basis. Special attention should be paid to the possibility of instrument failure and bleeding events for the patients with relative contraindications for PT.
    Surgery Today 01/2013; · 0.96 Impact Factor
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    ABSTRACT: Aortic aneurysm is caused by sclerosis of aortic wall. However, bad habits and chronic disease would be caused sclerosis of aortic wall. Therefore, bad habits and chronic diseases would possible affect aortic aneurysm, even after surgery. In this study, we used data mining to analyzed patient's history and lab data from pre-operation and post-operation to find the affect between aortic aneurysm and chronic disease. Then, we could be aimed difference of aortic aneurysm patient's chronic disease to let the patient to prevent or treat status early. Furthermore, it increased aortic aneurysm patient the effect of recovery after operator.
    Network-Based Information Systems (NBiS), 2013 16th International Conference on; 01/2013
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    ABSTRACT: The accelerated aging population around the world will be more obvious. In the USA, there will be about 72 million people aged 65 by 2030, There will have nearly 36.98% of the elderly population in Taiwan until 2050. Those people will need health care too. Nowadays, the current health care focus on the passive home care in Taiwan, however, the devices which can provide elder to carrying in outdoor will be huge and heavy, and also the devices will hard to actively send the alert message for the medical units when the patient have problem in their health. Therefore, the proposed of this study is to miniaturized vital sign detection and active alert system. The system will give elder the privacy, convenience, and security as well. Hoping this study can not only reduce the medical unit's work but lower the medical resources cost, moreover, it will also enhance the quality of life for the patients.
    Network-Based Information Systems (NBiS), 2013 16th International Conference on; 01/2013
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    ABSTRACT: BACKGROUND: Chronic renal failure (CRF) is associated with increased cardiovascular mortality, and medial vascular smooth muscle cell (VSMC) hypertrophy, proliferation, and calcification play a pivotal role in uremic vasculopathy. Glucose transporter-1 (GLUT1) facilitates the transport of glucose into VSMCs, and GLUT1 overexpression associated with high glucose influx leads to a stimulation of VSMC proliferation. However, the role of GLUT1 in uremic vasculopathy remains unclear. This study aimed to identify changes in the expression of GLUT1 in VSMCs in the setting of experimental uremia and investigate whether Akt/tuberous sclerosis complex subunit 2 (TSC2)/mammalian target of rapamycin (mTOR)/ribosomal S6 protein kinase (S6K) signaling, which plays a crucial role in VSMC proliferation and glucose metabolism, is involved in the regulation of GLUT1 expression. METHODS: In vivo experimental CRF was induced in Wistar rats by 5/6 nephrectomy, and the GLUT1 expression in aortic tissue was determined by the reverse transcriptase-polymerase chain reaction, immunoblotting, and immunohistochemical staining. Indoxyl sulfate (IS) is a uremic retention solute proven with pro-proliferative effect on rat VSMCs, and we further studied the expression of GLUT1 in rat A7r5 rat embryonic aortic cells stimulated by IS in the presence or absence of phloretin, a GLUT1 inhibitor, to explore the pathogenic role of GLUT1 in uremic vasculopathy. The contribution of Akt/TSC2/mTOR/S6K signaling in modifying the GLUT1 expression was also assessed. RESULTS: Eight weeks after 5/6 nephrectomy, aortic tissue obtained from CRF rats exhibited increased wall thickness and VSMC hypertrophy, hyperplasia, and degeneration. Compared with the sham-operated control group, the messenger (m)RNA and protein abundance of GLUT1 were both markedly increased in CRF rats. In vitro, IS induced a significant increase in expression of GLUT1 protein as well as pro-proliferative cyclin D1 and p21 mRNA and a modest increase in expression of antiapoptotic p53 mRNA in A7r5 cells, whereas inhibition of GLUT1 mediated glucose influx reduced the pro-proliferative and antiapoptotic effects of IS. In addition to increased GLUT1 expression, IS significantly suppressed Akt and TSC2 phosphorylation after 6-hour and 12-hour treatment, but increased S6K phosphorylation after 3-hour treatment. Inactivation of mTOR downstream signaling by rapamycin treatment inhibited S6K phosphorylation and abolished the stimulatory effect of IS on GLUT1 expression. CONCLUSIONS: In vivo and in vitro experimental CRF displayed prominent GLUT1 upregulation in VSMCs. The uremic toxin IS stimulated proliferation of VSMCs possibly through induction of GLUT1 expression. The Akt/TSC/mTOR/S6K signaling pathway may be one of the mechanisms underlying the upregulation of GLUT1 expression in uremic VSMCs.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 12/2012; · 3.52 Impact Factor
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    ABSTRACT: AIM: Circulating endothelial progenitor cells (EPCs) are associated with coronary artery disease (CAD) and predict its outcome. Although the pathophysiology of abdominal aortic aneurysm (AAA) is different, it shares some risk factors with CAD. Therefore, the correlation between EPCs and AAA was investigated. METHODS AND RESULTS: Seventy-eight subjects (age 77.2±7.8years) with suspected AAA were prospectively enrolled. Cut-off values (men, 3.5-5.5cm; women, 3-5cm) were used to define normal aorta, small AAA, and large AAA on thoraco-abdominal computer tomography. Endothelial function was measured by flow-mediated vasodilation (FMD). Flow cytometry and colony-forming units (CFUs) were used to evaluate circulating EPC numbers. Circulating EPCs were defined as mononuclear cells with low CD45 staining and double-positive staining for KDR, CD34, or CD133. Late out-growth EPCs were cultured from six patients with large AAAs and six age- and sex-matched controls to evaluate proliferation, adhesion, migration, tube formation, and senescence. FMD was significantly lower with large (5.26%±3.11%) and small AAAs (6.31%±3.66%) than in controls (8.88%±4.83%, P=0.008). Both CFUs (normal 38.39±12.99, small AAA 21.22±7.14, large AAA 6.98±1.97; P=0.026) and circulating EPCs (CD34(+)/KDR(+) and CD133(+)/KDR(+)) were significantly fewer in AAA patients than in controls. On multivariate analysis, CFUs and circulating EPCs (CD34(+)/KDR(+)) were independently, inversely correlated to AAA diameter. Proliferation, adhesion, migration, tube formation, and senescence of late EPCs were significantly impaired in AAA patients. CONCLUSION: The number and function of EPCs were impaired in AAA patients, suggesting their potential role in AAA.
    International journal of cardiology 11/2012; · 6.18 Impact Factor
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    ABSTRACT: OBJECTIVE: Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair (TEVAR) for aortic dissection. We investigated the mechanism of late distal SINE, prevention strategies, proper size selection of the stent graft, and implantation sequence. METHODS: From November 2006 to May 2011, 99 patients with aortic dissection underwent TEVAR with Zenith TX2 stent grafts (Cook, Bloomington, Ind) at our center. Among them, 27 distal SINEs were recognized. Eight of these patients with complicated distal SINE required intervention with new distal endografts, and all were enrolled for further analysis. RESULTS: Eight of the 27 patients with distal SINE underwent a secondary endograft procedure from February 2011 to July 2011. All were successfully treated without any complications or deaths. A high taper ratio (35% ± 11%) and excessive oversizing of the true lumen area at the distal stent level (293% ± 76%) were noted among these patients. CONCLUSIONS: The incidence of distal SINE seemed to be high; however, there were also low rates of death and complications after TEVAR for aortic dissection using stainless steel-based stent grafts. Complicated distal SINE can successfully be resolved by distal endograft implantation. Excessive oversizing of the distal stent graft, as measured by the true lumen area, may be a significant factor causing delayed distal SINE. Precise size selection is crucial for the distal end of the stent, especially for high taper ratio dissection pathology in which the implantation sequence of a distal small-sized stent graft first might be considered to prevent future distal SINE.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 11/2012; · 3.52 Impact Factor
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    ABSTRACT: OBJECTIVES: Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair of aortic dissection. We illustrate the possible mechanism by exploring predictive factors of late distal SINE after hybrid arch elephant trunk repair for aortic dissection. METHODS: From November 2006, to May 2011, 20 of 99 patients underwent hybrid arch repair using the elephant trunk graft as the proximal landing zone. After a mean follow-up period of 27.9 ± 12.0 months, 12 patients had late distal SINE events and the others were free of events. False lumen remodeling level was observed and maximal longitudinal diameter, average of longitudinal and transverse maximal diameter, circumference, and area of true lumen were analyzed for precise size selection of stent graft before and after the procedure. Taper ratio, true lumen:aorta ratio, prestent grafting oversizing ratio, poststent grafting oversizing ratio, and expansion mismatch ratio of distal true lumen were proposed and calculated for further evaluation of the mechanism of late distal SINE. RESULTS: Only the area oversizing ratio between true lumen and the distal selected stent graft at the presumed distal end of stent grafting was found as a significant predictive factor of SINE before procedure (4.00 ± 2.96 vs 1.98 ± 0.66 for SINE vs non-SINE, respectively; P = .031). The significant difference of the expansion mismatch ratio of true lumen between the 2 groups was found not only in the size measurement of mean diameter (1.48 ± 0.29 vs 1.22 ± 0.15; P = .039), but also in the area (2.39 ± 0.85 vs 1.58 ± 0.42; P = .031) and circumference (1.43 ± 0.27 vs 1.18 ± 0.14; P = .016) after stent grafting. CONCLUSIONS: We found that taper ratio is not an optimal criteria for stent graft size selection and distal oversizing calculated by true-lumen area is a significant factor causing delayed distal SINE. Use of the prestenting area oversizing ratio should be limited.
    The Journal of thoracic and cardiovascular surgery 10/2012; · 3.41 Impact Factor
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    ABSTRACT: Circulatory assist devices are applied to support patients with end-stage heart failure or circulatory collapse. Extracorporeal membrane oxygenation (ECMO) and ventricular assist device (VAD) are the two devices that are commonly used in these situations. However, in patients undergoing ECMO, complications occur more frequently and are more severe than in those with VAD, especially in patients with coagulopathy. The cause of coagulopathy is seldom reported; therefore, the current prospective study was designed to compare the coagulation status between patients who received ECMO and bridged VAD thereafter. The cases for our study were collected between December 2005 and January 2010. A total of 21 patients with VAD were enrolled. Seven patients received initial ECMO support and were subsequently shifted to VAD. Use of blood transfusion products by patients was recorded during application of ECMO and VAD. Thrombelastography (TEG) was performed pre-ECMO and pre-VAD, and thereafter to 1 week post-VAD implantation. The relevant parameters that were examined included coagulation time (R: resting, K: kinetics, seconds), angle (α, degrees), maximal amplitude (MA, mm), clot strength (G, dynes/cm(2)), and estimated percent lysis in 30 minutes (LY30, %). Coagulation status and average unit per day of blood transfusion at pre-VAD and post-VAD status were recorded. TEGs of pre-VAD and post-VAD implantation were compared in order to determine the frequency of bleeding. Average results from seven cases were incorporated into the current analysis. The patient transfusion requirement was reduced after implantation of the VAD. The TEG of post-VAD implantation was improved from the earlier pre-VAD results (ECMO status). Ultimately, TEG resulted in significant differences in R, K, angle, MA, and G, postoperatively. Coagulopathy of patients with VAD improved after bridging from ECMO, which can be attributed to improved coagulation factor and platelet function. Thus, bleeding complications are reduced.
    Journal of the Chinese Medical Association 08/2012; 75(8):363-9. · 0.75 Impact Factor

Publication Stats

283 Citations
149.21 Total Impact Points

Institutions

  • 2003–2014
    • National Yang Ming University
      • • Institute of Clinical Medicine
      • • School of Medicine
      • • Department of Surgery
      T’ai-pei, Taipei, Taiwan
  • 2002–2014
    • Taipei Veterans General Hospital
      • Surgery Division
      T’ai-pei, Taipei, Taiwan
  • 2012
    • Taipei City Hospital
      T’ai-pei, Taipei, Taiwan
  • 2005–2006
    • Taipei Medical University
      • School of Medicine
      Taipei, Taipei, Taiwan