The role of calpain-myosin 9-Rab7b pathway in mediating the expression of Toll-like receptor 4 in platelets: a novel mechanism involved in α-granules trafficking

Toll-like receptors (TLRs) plays a critical role in innate immunity. In 2004, Aslam R. and Shiraki R. first determined that murine and human platelets express functional TLRs. Additionally, Andonegui G. demonstrated that platelets express TLR4, which contributes to thrombocytopenia. However, the underlying mechanisms of TLR4 expression by platelets have been rarely explored until now. The aim of this study was to identify the mechanism of TLR4 expression underlying thrombin treatment. The human washed platelets were used in this study. According to flowcytometry and western blot analysis, the surface levels of TLR4 were significantly enhanced in thrombin-activated human platelets and decreased by TMB-8, calpeptin, and U73122, but not Y27632 (a Rho-associated protein kinase ROCK inhibitor) indicating that thrombin-mediated TLR4 expression was modulated by PAR/PLC pathway, calcium and calpain. Co-immunoprecipitation (co-IP) assay demonstrated that the interaction between TLR4 and myosin-9 (a substrate of calpain) was regulated by calpain; cleavage of myosin-9 enhanced TLR4 expression in thrombin treated platelets. Transmission electron microscope data indicated that human platelets used α-granules to control TLR4 expression; the co-IP experiment suggested that myosin-9 did not coordinate with Rab7b to negatively regulate TLR4 trafficking in thrombin treated platelets. In summary, phospholipase Cγ-calpain-myosin 9-Rab7b axis was responsible for the mechanism underlying the regulation of TLR4 containing α-granules trafficking in thrombin-stimulated platelets, which was involved in coagulation.

GroEL1, a heat shock protein 60 of Chlamydia pneumoniae, impairs neovascularization by decreasing endothelial progenitor cell function

The number and function of endothelial progenitor cells (EPCs) are sensitive to hyperglycemia, hypertension, and smoking in humans, which are also associated with the development of atherosclerosis. GroEL1 from Chlamydia pneumoniae has been found in atherosclerotic lesions and is related to atherosclerotic pathogenesis. However, the actual effects of GroEL1 on EPC function are unclear. In this study, we investigate the EPC function in GroEL1-administered hind limb-ischemic C57BL/B6 and C57BL/10ScNJ (a toll-like receptor 4 (TLR4) mutation) mice and human EPCs. In mice, laser Doppler imaging, flow cytometry, and immunohistochemistry were used to evaluate the degree of neo-vasculogenesis, circulating level of EPCs, and expression of CD34, vWF, and endothelial nitric oxide synthase (eNOS) in vessels. Blood flow in the ischemic limb was significantly impaired in C57BL/B6 but not C57BL/10ScNJ mice treated with GroEL1. Circulating EPCs were also decreased after GroEL1 administration in C57BL/B6 mice. Additionally, GroEL1 inhibited the expression of CD34 and eNOS in C57BL/B6 ischemic muscle. In vitro, GroEL1 impaired the capacity of differentiation, mobilization, tube formation, and migration of EPCs. GroEL1 increased senescence, which was mediated by caspases, p38 MAPK, and ERK1/2 signaling in EPCs. Furthermore, GroEL1 decreased integrin and E-selectin expression and induced inflammatory responses in EPCs. In conclusion, these findings suggest that TLR4 and impaired NO-related mechanisms could contribute to the reduced number and functional activity of EPCs in the presence of GroEL1 from C. pneumoniae.

Differential effect of phosphodiesterase-3 inhibitors on sympathetic hyperinnervation in healed rat infarcts

BACKGROUND

The effect of phosphodiesterase-3 (PDE-3) inhibitors on arrhythmia remains controversial, so the purpose of this study was to determine their differential effects on sympathetic hyperinnervation and the involved mechanisms in a rat model of myocardial infarction.

METHODS AND RESULTS

After ligating the coronary artery, male Wistar rats were randomized to cilostazol or milrinone, chemically unrelated inhibitors of PDE-3, or vehicle for 4 weeks. The postinfarction period was associated with increased myocardial norepinephrine levels and oxidant release, as measured by myocardial superoxide level and dihydroethidine fluorescence staining. Infarcted rats in the milrinone- and cilostazol-treated groups had favorable ventricular remodeling with similar potency. Compared with milrinone, cilostazol significantly increased interstitial adenosine levels and reduced the production of myocardial cAMP and superoxide. Cilostazol significantly blunted sympathetic hyperinnervation, as assessed by immunofluorescent analysis of sympathetic innervation, and western blotting and real-time quantitative RT-PCR of nerve growth factor. Furthermore, the inhibitory effect of cilostazol on nerve growth factor was reversed by 8-cyclopentyl-1,3-dipropylxanthine, a selective A1 receptor antagonist, and enhanced by tempol administration. In spite of similar arrhythmic vulnerability during programmed stimulation in both the vehicle-and cilostazol-treated groups, cilostazol did not have proarrhythmic effects compared with milrinone.

CONCLUSIONS

Unlike milrinone, cilostazol has therapeutic neutrality in arrhythmias because of adenosine uptake inhibition, which antagonizes the PDE-3-induced increase of sympathetic reinnervation via mediation of an adenosine A1 receptor-mediated antioxidation. 

C-reactive protein for predicting prognosis and its gender-specific associations with diabetes mellitus and hypertension in the development of coronary artery spasm

Background

While hypertension is negatively associated with coronary artery spasm (CAS), scarce data are available on diabetes mellitus in relation to CAS. In addition, outcome prediction in patients with CAS is challenging due to the lack of appropriate biomarkers. Therefore, we sought to identify the roles that gender, high-sensitivity C-reactive protein (hs-CRP), diabetes mellitus and hypertension play in CAS development and prognosis.

Methodology/Prinicpal Findings

Patients (350 women and 547 men) undergoing diagnostic coronary angiography with or without proven CAS but without obstructive stenosis were evaluated at long-term follow-up (median 102 months). Diabetic women and diabetic men with low hs-CRP levels had a low and high risk of CAS (odds ratio [OR]: 0.16, 95% confidence interval [CI]: 0.01–1.88 and OR: 5.02, 95% CI: 1.03–24.54, respectively). The ORs of CAS in both women and men with the highest hs-CRP tertile (>3 mg/L) reduced from 4.41 to 1.45 and 2.98 to 1.52, respectively, if they had diabetes mellitus, and from 9.68 to 2.43 and 2.60 to 1.75, respectively, if they had hypertension. Hypertension had a more negative effect on CAS development in diabetic than non-diabetic women, which was not observed in men. The highest hs-CRP tertile was an independent predictor of adverse outcomes. Patients with the highest hs-CRP tertile had more coronary events than patients with the lowest hs-CRP tertitle (p = 0.021, log-rank test).

Conclusions

Diabetes mellitus contributes to CAS development in men with low hs-CRP levels, but not in women. There are negative effects of diabetes mellitus and hypertension on CAS development in patients with high hs-CRP levels and especially in women. Elevated hs-CRP level independently predicts adverse outcomes.

Subacute bacterial endocarditis presenting as left upper quadrant abdominal pain

Infective endocarditis is a microbial infection of the endocardial surface of the heart. Its symptoms and signs are varied, and include fever, heart murmur, peripheral embolism, and heart failure. The diagnosis of subacute bacterial endocarditis (SBE) is suggested by a history of an indolent process characterized by fever, fatigue, anorexia, and unexplained weight loss. These patients may have had an invasive procedure, such as dental work, or abused intravenous drugs prior to the diagnosis of SBE. Although uncommon, the patients may present with nonspecific symptoms caused by peripheral embolic events. Herein, we report a 25-year-old male diagnosed with SBE, who presented with the unusual symptom of sudden onset of left upper quadrant abdominal pain for 2 days. His clinical history is also discussed.

Combined Framingham Risk Score and Coronary Artery Calcium Score Predict Subclinical Coronary Plaque Assessed by Coronary Computed Tomography Angiogram in Asymptomatic Taiwanese Population

BACKGROUND

We sought to determine the predictive value of the combined traditional Framingham risk score (FRS) and coronary artery calcium score (CACS) for subclinical coronary plaque detected by computed tomography coronary angiogram (CTCA) in asymptomatic subjects.

METHOD

We evaluated 167 asymptomatic Taiwanese subjects (mean age, 57 ± 11.2 years), who underwent CTCA as part of a health evaluation. We examined the associations between FRS, CACS, serum biomarkers, and coronary plaque assessed by CTCA.

RESULTS

Out of 167 subjects in the study, 95 had coronary artery atheroma. Of those possible predictors for coronary atherosclerosis, both FRS and CACS were independent predictors for the presence of coronary plaque [relative risk (RR): 1.29, 95% confidence interval (CI): 1.07-1.54, p = 0.006 and RR: 1.42, 95% CI: 1.16-1.75, p = 0.001, respectively]. Receiver operating characteristics curve analysis revealed that CACS and FRS were indicators of the presence of coronary plaque. The area under the curve for FRS and CACS was 0.729 and 0.889, respectively (p < 0.001). Furthermore, the area under the curve for combination of FRS and CACS was 0.936 (95% CI: 0.887-0.969, p < 0.001), and this combination provided a better diagnostic advantage than either FRS or CACS alone (p < 0.001 and p = 0.012 by C-statistic, respectively).

CONCLUSIONS

In asymptomatic Taiwanese subjects with low to intermediate cardiovascular risk, both FRS and CACS were independently related to subclinical atherosclerosis. A combined FRS and CACS evaluation improved the efficacy of prediction for atherosclerotic plaque burden.

KEY WORDS

Atherosclerosis; Computed coronary tomography angiogram; Coronary artery calcium score; Framingham risk score; Subclinical coronary plaque.

Both PKA and Epac pathways mediate N-acetylcysteine-induced Connexin43 preservation in rats with myocardial infarction

Cardiac remodeling was shown to be associated with reduced gap junction expression after myocardial infarction. A reduction in gap junctional proteins between myocytes may trigger ventricular arrhythmia. Therefore, we investigated whether N-acetylcysteine exerted antiarrhythmic effect by preserving connexin43 expression in postinfarcted rats, focusing on cAMP downstream molecules such as protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac). Male Wistar rats after ligating coronary artery were randomized to either vehicle, or N-acetylcysteine for 4 weeks starting 24 hours after operation. Infarct size was similar between two groups. Compared with vehicle, cAMP levels were increased by N-acetylcysteine treatment after infarction. Myocardial connexin43 expression was significantly decreased in vehicle-treated infarcted rats compared with sham operated rats. Attenuated connexin43 expression and function were blunted after administering N-acetylcysteine, assessed by immunofluorescent analysis, dye coupling, Western blotting, and real-time quantitative RT-PCR of connexin43. Arrhythmic scores during programmed stimulation in the N-acetylcysteine-treated rats were significantly lower than those treated with vehicle. In an ex vivo study, enhanced connexin43 levels afforded by N-acetylcysteine were partially blocked by either H-89 (a PKA inhibitor) or brefeldin A (an Epac-signaling inhibitor) and completely blocked when H-89 and brefeldin A were given in combination. Addition of either the PKA specific activator N6Bz or Epac specific activator 8-CPT did not have additional increased connexin43 levels compared with rats treated with lithium chloride alone. These findings suggest that N-acetylcysteine protects ventricular arrhythmias by attenuating reduced connexin43 expression and function via both PKA- and Epac-dependent pathways, which converge through the inactivation of glycogen synthase kinase-3β.

Dipeptidyl peptidase-4 inhibitor improves neovascularization by increasing circulating endothelial progenitor cells

BACKGROUND AND PURPOSE

Current methods used to treat critical limb ischaemia (CLI) are hampered by a lack of effective strategies, therefore, therapeutic vasculogenesis may open up a new field for the treatment of CLI. In this study we investigated the ability of the DPP-4 inhibitor, sitagliptin, originally used as a hypoglycaemic agent, to induce vasculogenesis in vivo.

EXPERIMENTAL APPROACH

Sitagliptin were administered daily to C57CL/B6 mice and eGFP transgenic mouse bone marrow-transplanted ICR mice that had undergone hindlimb ischaemic surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and circulating levels of endothelial progenitor cells (EPCs) respectively. Cell surface markers of EPCs and endothelial NOS (eNOS) in vessels were studied.

KEY RESULTS

Sitagliptin elevated plasma glucagon-like peptide-1 (GLP-1) levels in mice subjected to ischaemia, decreased plasma dipeptidyl peptidase-4 (DPP-4) concentration, and augmented ischaemia-induced increases in stromal cell-derived factor-1 (SDF-1) in a dose-dependent manner. Blood flow in the ischaemic limb was significantly improved in mice treated with sitagliptin. Circulating levels of EPCs were also increased after sitagliptin treatment. Sitagliptin also enhanced the expression of CD 34 and eNOS in ischaemic muscle. In addition, sitagliptin promoted EPC mobilization and homing to ischaemic tissue in eGFP transgenic mouse bone marrow-transplanted ICR mice.

CONCLUSION AND IMPLICATIONS

Circulating EPC levels and neovasculogenesis were augmented by the DPP-4 inhibitor, sitagliptin and this effect was dependent on an eNOS-related pathway in a mouse model of hindlimb ischaemia. The results indicate that oral administration of sitagliptin has therapeutic potential as an inducer of vasculogenesis.

Gender-specific prognosis and risk impact of C-reactive protein, hemoglobin and platelet in the development of coronary spasm

BACKGROUND

Scarce data are available on hemoglobin and platelet in relation to coronary artery spasm (CAS) development. We sought to determine the roles that high-sensitivity C-reactive protein (hs-CRP), hemoglobin and platelet play in CAS patients.

METHODS

Patients (337 women and 532 men) undergoing coronary angiography with or without CAS but without obstructive coronary artery disease were evaluated during a 12-year period.

RESULTS

Among women with high hemoglobin levels, the odds ratios (OR) from the lowest (<1 mg/l) to the highest tertiles (>3 mg/l) of hs-CRP were 1.21, 2.15, and 5.93 (p=0.009). In women with low hemoglobin levels, an elevated risk was found from the middle to the highest tertiles of hs-CRP (OR 0.59 to 3.85) (p=0.004). This relationship was not observed in men. In men, platelet count was the most significant risk factor for CAS (p=0.004). The highest likelihood of developing CAS was found among women with the highest hs-CRP tertile and low platelet counts (OR 8.77; 95% confidence interval [CI] 2.20-35.01) and among men with the highest hs-CRP tertile and high platelet counts (OR 4.58; 95% CI 0.48-43.97). Neither hemoglobin level nor platelet count was associated with frequent recurrent angina in both genders with CAS whereas death and myocardial infarction were rare.

CONCLUSIONS

There are positive interactions among hs-CRP, hemoglobin and platelet in women with this disease, but not in men. While hemoglobin is a modifier in CAS development in women, platelet count is an independent risk factor for men. Both women and men have good prognosis of CAS.

Students' view upon graduation: a survey of medical education in Taiwan

BACKGROUND

Improving the quality of medical education is a key goal of government policy in Taiwan. The aim of this study was to reflect the responses of medical education from the perspective of graduating medical students in Taiwan. This is the first survey study of medical education in Taiwan.

METHODS

Using the Medical School Graduation Questionnaire from the Association of American Medical Colleges (AAMC), we distributed 406 questionnaires to medical students of four medical schools in their last semester, and received 270 back (response rate, 66.5%). There were 11 medical schools in Taiwan. Most questions were assessed on a 5-point Likert scale.

RESULTS

Students identified genetics, biochemistry, and ethics as the three most important premedical subjects preparing them for medical education and gross anatomy, physiology, and pharmacology as the three most helpful basic science subjects preparing them for clinical clerkships and electives. Most Taiwanese students were satisfied with their learning experience in internal medicine. Only 55.9% of students were confident that they had acquired the clinical skills required to become a resident, and 70.7% were satisfied with the quality of their medical education.

CONCLUSION

The study offers preliminary results on the views of graduating students on the medical education system in Taiwan. In particular, our government and medical educators need to continuously put more effort into building students' confidence in their clinical skills.

An endoluminal aortic prosthesis infection presenting as pneumoaorta and aortoduodenal fistula

Herein, we present a case of pneumoaorta and aortoduodenal fistula (ADF) caused by an endoluminal aortic prosthesis infection. An 82-year-old man underwent endovascular aneurysm repair with a stent graft to exclude a 5.1-cm abdominal aortic aneurysm. Three months after the index procedure, the patient was taken to the emergency department at a medical university hospital. He presented with a 2-d history of bloody diarrhea. An endoluminal aortic stent graft infection was diagnosed, and an ADF was identified. The patient died of septic shock despite emergency surgery and intensive care. When encountered, stent graft infections require appropriate antibiotics and graft explantation. The diagnosis of an ADF is important, and surgery remains the most effective management if septic shock presents despite conservative treatment.

Moderate to High Concentrations of High-Density Lipoprotein From Healthy Subjects Paradoxically Impair Human Endothelial Progenitor Cells and Related Angiogenesis by Activating Rho-Associated Kinase Pathways

Objective—

Recent clinical evidence has failed to demonstrate the benefits of elevation of serum high-density lipoprotein (HDL), suggesting potential loss of protective effects of HDL at high concentrations. This study aimed to investigate the concentration-related effects of HDL on in vitro and in vivo functions of human endothelial progenitor cells (EPCs) and related angiogenesis.

Methods and Results—

Early and late outgrowth EPCs were generated from human circulating mononuclear cells. Oxidized low-density lipoprotein reduced viability of late outgrowth EPCs, which was reversed dose dependently by HDL. In the absence of oxidized low-density lipoprotein, HDL at low concentrations (5–50 μg/mL, equal to 0.5–5 mg/dL in human) enhanced EPC tube formation by activating phosphatidylinositol-3 kinase/Akt/endothelial NO synthase pathways. Moderate to high concentrations (400–800 μg/mL) of HDL paradoxically enhanced EPC senescence and impaired tube formation by activating Rho-associated kinase (ROCK) and inhibiting phosphatidylinositol-3 kinase/Akt and p38 mitogen-activated protein kinase pathways. Rho-associated kinase inhibitors, either Y27632 or statins, prevented high HDL–induced EPC senescence and improved in vitro tube formation, as well as in vivo capacity of angiogenesis of EPCs.

Conclusion—

While protecting EPCs from the injury of oxidized low-density lipoprotein, moderate to high concentrations of HDL paradoxically impaired EPCs and related angiogenesis in the absence of oxidized low-density lipoprotein by activating Rho-associated kinase pathways, providing mechanistic evidence of potential hazard effects of HDL.

Reversible left ventricular apical ballooning associated with jet lag in a Taiwanese woman: A case report

Reversible left ventricular apical ballooning, without coronary artery stenosis, is a novel heart syndrome mimicking acute myocardial infarction, and is very rare in Taiwan. A 74-year-old Taiwanese woman returned from travelling abroad for one week and suffered from persistent, severe jet lag with sleep disturbance. She had a cold exacerbated by bronchial asthma for three days. She presented with sudden onset of chest pain after drinking three cups of coffee and taking a sauna for more than 1 h. On admission, an electrocardiogram showed ST segment elevation in leads II, III, aVF and V(3-6), and cardiac enzyme tests revealed minimal elevation. An echocardiogram showed apical ballooning and basal hyperkinesias of the left ventricle (LV) in systole. A coronary angiogram on the second day was normal, while the ST segment was still elevated, and the patient continued to experience chest pain. A negative T wave developed three days later. The electrocardiogram abnormality and LV dysfunction resolved completely six months later. A takotsubo (ampulla) cardiomyopathy was diagnosed. The activated myocardial adrenergic nervous system, stimulated by acute and marked stress in this patient, with more adrenergic innervations distributed in the apex of the LV, may be the trigger for this novel cardiac syndrome.

GroEL1, from Chlamydia pneumoniae, induces vascular adhesion molecule 1 expression by p37(AUF1) in endothelial cells and hypercholesterolemic rabbit

The expression of vascular adhesion molecule-1 (VCAM-1) by endothelial cells may play a major role in atherogenesis. The actual mechanisms of chlamydia pneumoniae (C. pneumoniae) relate to atherogenesis are unclear. We investigate the influence of VCAM-1 expression in the GroEL1 from C. pneumoniae-administered human coronary artery endothelial cells (HCAECs) and hypercholesterolemic rabbits. In this study, we constructed the recombinant GroEL1 from C. pneumoniae. The HCAECs/THP-1 adhesion assay, tube formation assay, western blotting, enzyme-linked immunosorbent assay, actinomycin D chase experiment, luciferase reporter assay, and immunohistochemical stainings were performed. The results show that GroEL1 increased both VCAM-1expression and THP-1 cell adhesives, and impaired tube-formation capacity in the HCAECs. GroEL1 significantly increased the VCAM-1 mRNA stability and cytosolic AU-binding factor 1 (AUF1) level. Overexpression of the p37^AUF1 significantly increased VCAM-1 gene expression in GroEL1-induced bovine aortic endothelial cells (BAECs). GroEL1 prolonged the stability of VCAM-1 mRNA by increasing both p37^AUF1 and the regulation of the 5′ untranslated region (UTR) of the VCAM-1 mRNA in BAECs. In hypercholesterolemic rabbits, GroEL1 administration enhanced fatty-streak and macrophage infiltration in atherosclerotic lesions, which may be mediated by elevated VCAM-1 expression. In conclusion, GroEL1 induces VCAM-1 expression by p37^AUF1 in endothelial cells and enhances atherogenesis in hypercholesterolemic rabbits.

Effect of sildenafil on ventricular arrhythmias in post-infarcted rat hearts

We have demonstrated that activation of ATP-sensitive potassium (K(ATP)) channels can attenuate sympathetic hyperinnervation. Sildenafil, a phosphodiesterase-5 inhibitor, has been shown to provide a preconditioning-like cardioprotective effect via opening of K(ATP) channels. The aim of this study was to investigate whether chronic administration of sildenafil attenuates cardiac sympathetic hyperinnervation after myocardial infarction through activation of K(ATP) channels and to compare it with the nitric oxide donor isosorbide dinitrate. Male Wistar infarcted rats induced by ligation of the anterior descending artery were randomized to either vehicle, nicorandil, sildenafil, isosorbide dinitrate, glibenclamide, or a combination of nicorandil and glibenclamide, or sildenafil and glibenclamide. Myocardial norepinephrine levels revealed a significant elevation in vehicle-treated rats compared with sham-operated rats, consistent with sympathetic hyperinnervation after infarction assessed by immunohistochemical analysis for tyrosine hydroxylase, growth associated factor 43 and neurofilament and by protein expression and mRNA of nerve growth factor. Sympathetic hyperinnervation was reduced after administering either nicorandil or sildenafil. Arrhythmic scores during programmed stimulation in the sildenafil-treated rats were significantly lower than those treated with the vehicle. Furthermore, the beneficial effects of sildenafil-induced were reversed by the addition of either glibenclamide or 5-hydroxydecanoate, implicating mitochondrial K(ATP) channels as the relevant target. Isosorbide dinitrate failed to confer similar antiarrhythmia. 1H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one, a soluble guanylyl cyclase inhibitor, did not influence the effect of sildenafil on the nerve growth factor. These data indicate that sildenafil after infarction attenuated sympathetic hyperinnervation and arrhythmias by activation of mitochondrial K(ATP) channels through a guanylyl cyclase-cGMP-independent pathway.

Extracorporeal membrane oxygenation-assisted primary percutaneous coronary intervention may improve survival of patients with acute myocardial infarction complicated by profound cardiogenic shock

PURPOSE

The aim of this study was to evaluate the impact of extracorporeal membrane oxygenation (ECMO) assistance on the clinical outcome of patients with acute myocardial infarction (AMI) that is complicated by profound cardiogenic shock (CS) who received primary percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

We collected patients from January 2004 through December 2006 (stage 1); 25 patients who presented with AMI and received primary PCI and had profound CS were enrolled in the study. Intraaortic balloon counterpulsation (IABP) was the only modality for extracorporeal support in our hospital. From January 2007 through December 2009 (stage 2), 33 patients who presented with AMI and received primary PCI and had profound CS were enrolled; for this stage; both intra-aortic balloon counter-pulsation and ECMO support were available in our facility.

RESULTS

A Kaplan-Meier survival analysis displayed significantly improved survival for patients in stage 2 (P = .001; 1-year survival in stage 1 vs 2; 24% vs 63.64%). Patients presenting with either STEMI (ST segment elevation myocardial infarction) or NSTEMI (Non-ST segment elevation myocardial infarction) benefited from ECMO-assisted PCI (P < .05). In stage 1, patients with refractory ventricular tachycardia/ventricular fibrillation had a very low survival rate; however, in stage 2, the survival rate of patients with and without refractory ventricular tachycardia/ventricular fibrillation was similar (P = .316).

CONCLUSION

Extracorporeal membrane oxygenation-assisted PCI for patients with AMI that is complicated by profound CS may improve the 30-day and 1-year survival rates.

Reversible ischemia on treadmill exercise in left main coronary artery vasospasm

Coronary vasospasm of the left main coronary artery (LMCA) is a rare condition with potentially devastating consequences. We present 2 patients with LMCA vasospasm-related angina, the first being a 46-year-old woman and the second a 51-year-old woman. Both of them developed ST-segment ischemic changes on treadmill exercise tests. Coronary angiography showed spontaneous LMCA vasospasm in one patient and methylergonovine-induced LMCA vasospasm in the other patient. Follow-up treadmill exercise tests revealed no exercise-induced ischemia after calcium antagonist monotherapy. These cases demonstrate the importance of identifying LMCA vasospasm, as the treatment of choice varies in patients with angina pectoris. Reversible myocardial ischemia caused by LMCA vasospastic angina can be controlled by calcium antagonist monotherapy and detected by repeat non-invasive stress testing.

Magnetic resonance venography evaluating veins flow for legs by application of long stretch elastic bandage

AIM

Varicose veins are a common feature of chronic venous disease that causes pain and swelling of legs. Long stretch elastic bandages are one of the methods used to prevent and treat venous disease, but diagnostic benefit by magnetic resonance imaging (MRI) is not widely promoted. This study aims to evaluate the effects of long stretch elastic bandages using a non-contrast magnetic resonance venographic (MRV) technique by detecting influence on circumferences and flow velocities of varicose and deep veins, before and immediately after application of long stretch elastic bandages.

METHODS

Twelve patients presenting with visible varicose veins underwent MRV. The level of the superficial varicose and deep veins before and after wearing long stretch elastic bandages was recorded.

RESULTS

By comparing before and after long stretch elastic bandages, all 12 cases showed statistical significant decrease of the superficial venous flow areas; 9 out of 12 cases showed statistical significant change of the superficial (decreased) and deep (increased) venous flow rates. However, due to technical limitation, over half of the cases could not record the change of the deep venous flow areas.

CONCLUSION

The non-contrast MRV technique with Cine phase contrast, is capable to detect the short term beneficial effects of long stretch elastic bandages by measuring change of the superficial venous flow areas and superficial and deep venous flow rates.

Traditional Chinese medicine, Xue-Fu-Zhu-Yu decoction, potentiates tissue plasminogen activator against thromboembolic stroke in rats

AIM OF THIS STUDY

The Xue-Fu-Zhu-Yu decoction (XFZYD) is a well-known traditional Chinese medicine for treating cardiovascular diseases. The therapeutic effects of this XFZYD have been well documented especially in treating of atherosclerosis and hyperlipidemia. Since this decoction can induce endothelial progenitor cell angiogenesis, it can provide experimental evidence for the treatment of ischemic diseases. Patients who are admitted to the hospital with acute ischemic stroke are initially considered candidates for the recombinant tissue plasminogen activator (rt-PA). However, rt-PA therapy is still lesser than ideal due to its major side effect of hemorrhaging. Therefore, medical research has been devoted to finding an alternative and/or complementary therapy for ischemic stroke. In the present study, we evaluated the protective effect of the combination of XFZYD with or without rt-PA in a rat model of thromboembolic stroke.

MATERIALS AND METHODS

A cerebral thromboembolic stroke animal model and immunoblotting analysis were used to assess the effects of XFZYD and rt-PA.

RESULTS

Treatment with rt-PA (8 mg/kg) or XFZYD (1.5 and 3.0 g/kg/day) alone showed slight reductions in the infarct volume compared to solvent-treated rats. However, XFZYD (1.5 and 3.0 g/kg/day) obviously potentiated rt-PA-mediated reduction in the infarct volume in cerebral ischemic regions. In addition, treatment with rt-PA significantly reduced both tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS) but not hypoxia-inducible factor (HIF)-1 α or active caspase-3 expressions in ischemic regions, whereas treatment with XFZYD (3.0 g/kg/day) significantly reduced all of these protein expressions in ischemic regions. Moreover, treatment with XFZYD (1.5 and 3.0 g/kg/day) obviously potentiated rt-PA-mediated reductions in TNF-α, iNOS, HIF-1 α, and active caspase-3 expressions.

CONCLUSIONS

Results of this study suggest that XFZYD potentiated rt-PA-mediated neuroprotection against thromboembolic stroke in rats. This neuroprotection is probably mediated by the inhibition of HIF-1 α and TNF-α, followed by the inhibition of inflammatory responses (i.e., iNOS) and apoptosis (active caspase-3). These results provide a better understanding of the scientific validation of the therapeutic value of the combination of XFZYD with rt-PA in ischemic stroke.

Ursolic acid induces allograft inflammatory factor-1 expression via a nitric oxide-related mechanism and increases neovascularization

Ursolic acid (UA), a triterpenoid compound found in plants, is used in the human diet and in medicinal herbs and possesses a wide range of biological benefits including antioxidative, anti-inflammatory, and anticarcinogenic effects. Endothelial expression of allograft inflammatory factor-1 (AIF-1) mediates vasculogenesis, and nitric oxide (NO) produced by endothelial NO (eNOS) represents a mechanism of vascular protection. It is unclear whether UA affects the neovascularization mediated by AIF-1 and eNOS expression. This study investigated the effects and mechanisms of UA on angiogenesis in vivo in hind limb ischemic animal models and in vitro in human coronary artery endothelial cells (HCECs). This study explored the impact of UA on endothelial cell (EC) activities in vitro in HCECs, vascular neovasculogenesis in vivo in a mouse hind limb ischemia model, and the possible role of AIF-1 in vasculogenesis. The results demonstrate that UA enhances collateral blood flow recovery through induction of neovascularization in a hind limb ischemia mouse model. In vitro data showed that UA increases tube formation and migration capacities in human endothelial cells, and exposing HCECs to UA increased AIF-1 expression through a NO-related mechanism. Moreover, UA administration increased capillary density and eNOS and AIF-1 expression in ischemic muscle. These findings suggest that UA may be a potential therapeutic agent in the induction of neovascularization and provide a novel mechanistic insight into the potential effects of UA on ischemic vascular diseases.

Granulocyte colony-stimulating factor increases sympathetic reinnervation and the arrhythmogenic response to programmed electrical stimulation after myocardial infarction in rats

Granulocyte colony-stimulating factor (G-CSF) has been used for the repair of infarcted myocardium, but concerns have been raised regarding its proarrhythmic potential. We analyzed the influence of G-CSF treatment on sympathetic nerve remodeling and the expression of nestin in a rat model of experimental myocardial infarction (MI). Twenty-four hours after ligation of the anterior descending artery, male Wistar rats were randomized to receive either saline (MI/C) or G-CSF (MI/G) for 5 days. At 56 days after infarction, MI/G rats had a significantly higher left ventricular ejection fraction accompanied by a significant decrease in the left ventricular end-diastolic dimension than the MI/C group. Myocardial norepinephrine levels revealed a significant elevation in MI/G rats in the border zone compared with MI/C rats. Immunohistochemical analysis for tyrosine hydroxylase, growth-associated protein 43, and neurofilament also confirmed the changes of myocardial norepinephrine. At 5 days after infarction, MI/G rats had increased numbers of tissue-infiltrated CD34(+) cells, although a similar increase in circulating neutrophil counts between sham-operated rats treated with G-CSF and MI/G rats was observed. Compared with MI/C rats, MI/G rats showed an increase of nestin and nerve growth factor expression, as assessed by protein expression and mRNA levels. The arrhythmia scores during programmed stimulation were significantly higher in MI/G rats than in MI/C rats, suggesting proarrhythmic potential. These findings suggest that, although G-CSF administration after infarction improved myocardial function, it resulted in the activation of nestin and nerve growth factor expression and increased sympathetic reinnervation, which may increase the arrhythmogenic response to programmed electrical stimulation.