The utilization and prognostic impact of B-type Natriuretic Peptide in hospitalized acute decompensated heart failure in an Asian population.

BACKGROUND: B-type natriuretic peptide (BNP) levels during admission have been shown to have prognostic value in the diagnosis of heart failure and further predict the in-hospital mortality of acute decompensated heart failure (ADHF). This study describes the characteristics of BNP among hospitalized ADHF and elucidates its prognostic value of in-hospital mortality in an Asian population. METHODS: We consecutively studied patients aged 20+ who were discharged with a diagnosis of ADHF from March 2013 to March 2014 in a tertiary hospital of northern Taiwan by reviewing medical records. Prognostic predictors of mortality were assessed using Cox proportional hazard regression models. BNP > 100 pg/ml was used as the cut-off for defining abnormally high BNP based on current clinical practice criteria. RESULTS: After implementation of our exclusion criteria, a total of 1,807 patients hospitalized with ADHF were studied. Compared to those subjects with BNP ≤100 pg/ml, individuals with higher BNP tended to have more advanced age, more clusters of the typical signs of heart failure (HF) (e.g., peripheral edema or lung rales) at presentation, lower ejection fraction, lower hemoglobin levels, more disturbed biochemical data, worsened renal function, and twice the risk for in-hospital mortality (15.2 vs 6.2 %, all p < 0.05). In a multivariate analysis, more advanced age, the presence of rales, a worse New York Heart Association functional class, wider QRS duration, and abnormal BNP levels (>100 pg/ml) were all associated with in-hospital mortality among admitted HF patients after accounting for clinical co-variates and global ventricular ejection fraction (HR: 2.17, 95 % CI: 1.15-6.64, p = 0.024). CONCLUSION: Abnormally high BNP levels in ADHF patients during admission were tightly linked to clinical features of worse physical, functional, and clinical presentations, and further provided prognostic value for determining in-hospital mortality among patients with ADHF in an Asian population.

Reduction of connexin43 in human endothelial progenitor cells impairs the angiogenic potential.

Our previous work showed that arsenic trioxide down-regulated Cx43 and attenuated the angiogenic potential of human late endothelial progenitor cells (EPC). However, the relation between Cx43 and angiogenic activity of the EPC remained unclear. In the study, human late EPC were treated with siRNA specific to Cx43 (Cx43siRNA). The expression profiles as well as activity of the treated cells were examined. In parallel, the angiogenic potential of human EPC treated with Cx43siRNA was evaluated using murine hind limb ischemic model. The results showed that, in the EPC treated with Cx43siRNA, the activity of migration, proliferation, and angiogenic potential were attenuated, accompanied by reduction in vascular endothelial growth factor (VEGF) expression. In hind limb ischemia mice, EPC treated with Cx43siRNA lost the therapeutic angiogenic potential. VEGF supplementation partially recovered the activity impaired by Cx43 down-regulation. In conclusion, reduced Cx43 expression per se in the EPC causes decreased expression of VEGF and impaired angiogenic potential of the cells. Prevention of Cx43 reduction is a potential target to maintain the angiogenic potential of the EPC.

The increase of VEGF secretion from endothelial progenitor cells post ultrasonic VEGF gene delivery enhances the proliferation and migration of endothelial cells.

We investigated the feasibility of exogenous gene expression in endothelial progenitor cells (EPCs) through the use of ultrasonic microbubble transfection (UMT). EPCs originating from porcine peripheral blood were cultured in a medium containing constructed vascular endothelial growth factor (VEGF) pDNA followed by UMT. Simultaneously, comprehensive functional evaluations were conducted to investigate the effects of UMT of the VEGF gene on the EPCs. The results showed that UMT yielded significant VEGF protein expression. VEGF-containing supernatant originating from EPCs post UMT led to significantly enhanced activities of proliferation by more than 20% and migration by approximately 30% in human aortic endothelial cells. The duration of additional secretion of VEGF protein attributable to the exogenous VEGF gene in the EPCs post UMT lasted more than 96 hours. In conclusion, UMT successfully delivers the VEGF gene into porcine EPCs, and VEGF-containing supernatant derived from EPCs post UMT enhances the proliferation and migration of human aortic endothelial cells.

Rare case of left-dominant arrhythmogenic right ventricular cardiomyopathy with dramatic reverse remodeling after cardiac resynchronization as an adjunct to pharmacological therapy.

A 57-year-old man presented with near syncope and hemodynamic compromise after exercise. A sustained ventricular tachycardia (VT) of right bundle-branch block morphology was evident upon examination at our emergency department. Baseline 12-lead electrocardiography revealed a sinus rhythm with a complete left bundle-branch block after successful cardioversion of the VT. Coronary angiography revealed patent coronary arteries, whereas left ventriculography demonstrated impaired systolic function, accompanied by a peculiar basal lateral aneurysm. Both echocardiography and magnetic resonance imaging were consistent with a diagnosis of left-dominant arrhythmogenic right ventricular cardiomyopathy. Four months later, substantial ventricular reverse remodeling and clinical improvements were observed after cardiac resynchronization therapy with a defibrillator, as an adjunct to conventional pharmacological therapy.

Relation of carotid artery diameter with cardiac geometry and mechanics in heart failure with preserved ejection fraction.

BACKGROUND: Central artery dilation and remodeling are associated with higher heart failure and cardiovascular risks. However, data regarding carotid artery diameter from hypertension to heart failure have remained elusive. We sought to investigate this issue by examining the association between carotid artery diameter and surrogates of ventricular dysfunction. METHODS AND RESULTS: Two hundred thirteen consecutive patients including 49 with heart failure and preserved ejection fraction (HFpEF), 116 with hypertension, and an additional 48 healthy participants underwent comprehensive echocardiography and tissue Doppler imaging. Ultrasonography of the common carotid arteries was performed for measurement of intima-media thickness and diameter (CCAD). Cardiac mechanics, including LV twist, were assessed by novel speckle-tracking software. A substantial graded enlargement of CCAD was observed across all 3 groups (6.8 ± 0.6, 7.7 ± 0.73, and 8.7 ± 0.95 mm for normal, hypertension, and HFpEF groups, respectively; ANOVA P<0.001) and correlated with serum brain natriuretic peptide level (R(2)=0.31, P<0.001). Multivariable models showed that CCAD was associated with increased LV mass, LV mass-to-volume ratio (ß-coefficient=10.9 and 0.11, both P<0.001), reduced LV longitudinal and radial strain (ß-coeffficient=0.81 and -3.1, both P<0.05), and twist (ß-coefficient=-0.84, P<0.05). CCAD set at 8.07 mm as a cut-off had a 77.6% sensitivity, 82.3% specificity, and area under the receiver operating characteristic curves (AUROC) of 0.86 (95% CI 0.80 to 0.92) in discriminating HFpEF. In addition, CCAD superimposed on myocardial deformation significantly expanded AUROC (for longitudinal strain, from 0.84 to 0.90, P of ΔAUROC=0.02) in heart failure discrimination models. CONCLUSIONS: Increased carotid artery diameter is associated with worse LV geometry, higher brain natriuretic peptide level, and reduced contractile mechanics in individuals with HFpEF.

Epicardial adipose tissue relating to anthropometrics, metabolic derangements and fatty liver disease independently contributes to serum high-sensitivity C-reactive protein beyond body fat composition: a study validated with computed tomography.

BACKGROUND: Epicardial adipose tissue (EAT) measured by echocardiography has been proposed to be associated with metabolic syndrome and increased cardiovascular risks. However, its independent association with fatty liver disease and systemic inflammation beyond clinical variables and body fat remains less well known. METHODS: The relationships between EAT and various factors of metabolic derangement were retrospectively examined in consecutive 359 asymptomatic subjects (mean age, 51.6 years; 31% women) who participated in a cardiovascular health survey. Echocardiography-derived regional EAT thickness from parasternal long-axis and short-axis views was quantified. A subset of data from 178 randomly chosen participants were validated using 16-slice multidetector computed tomography. Body fat composition was evaluated using bioelectrical impedance from foot-to-foot measurements. RESULTS: Increased EAT was associated with increased waist circumference, body weight, and body mass index (all P values for trend = .005). Graded increases in serum fasting glucose, insulin resistance, and alanine transaminase levels were observed across higher EAT tertiles as well as a graded decrease of high-density lipoprotein (all P values for trend <.05). The areas under the receiver operating characteristic curves for identifying metabolic syndrome and fatty liver disease were 0.8 and 0.77, with odds ratio estimated at 3.65 and 2.63, respectively. In a multivariate model, EAT remained independently associated with higher high-sensitivity C-reactive protein and fatty liver disease. CONCLUSIONS: These data suggested that echocardiography-based epicardial fat measurement can be clinically feasible and was related to several metabolic abnormalities and independently associated fatty liver disease. In addition, EAT amount may contribute to systemic inflammation beyond traditional cardiovascular risks and body fat composition.

Slow conduction and gap junction remodeling in murine ventricle after chronic alcohol ingestion.

BACKGROUND: Long-term heavy alcohol drinkers are prone to the development of cardiac arrhythmia. To understand the mechanisms, we evaluated the cardiac structural and electrophysiological changes in mice chronically drinking excessive alcohol. RESULTS: Male C57BL/6J mice were given 36% alcohol in the drinking water. Those given blank water were used as control. Twelve weeks later, the phenotypic characteristics of the heart, including gap junctions and electrical properties were examined. In the alcohol group the ventricles contained a smaller size of cardiomyocytes and a higher density of capillary networks, compared to the control. Western blots showed that, after drinking alcohol, the content of connexin43 (Cx43) protein in the left ventricle was increased by 18% (p < 0.05). Consistently, immunoconfocal microscopy demonstrated that Cx43 gap junctions were up-regulated in the alcohol group with a disorganized distribution, compared to the control. Optical mapping showed that the alcohol group had a reduced conduction velocity (40 ± 18 vs 60 ± 7 cm/sec, p < 0.05) and a higher incidence of ventricular tachyarrhythmia (62% vs 30%, p < 0.05). CONCLUSION: Long-term excessive alcohol intake resulted in extensive cardiac remodeling, including changes in expression and distribution of gap junctions, growth of capillary network, reduction of cardiomyocyte size, and decrease of myocardial conduction.

Therapeutic angiogenesis of human early endothelial progenitor cells is enhanced by thrombomodulin.

OBJECTIVE: We examined the effect of thrombomodulin (TM) domains 2 and 3 (TMD23) on human early endothelial progenitor cells (EPCs). METHODS AND RESULTS: TM was expressed and released by human EPCs cultured from peripheral blood mononuclear cells (PBMCs). Addition of TMD23 (100 ng/mL) to the cultured PBMCs increased the colony-forming units, chemotactic motility, matrix metalloproteinase activity, and interleukin-8 secretion but decreased tumor necrosis factor-α (TNF-α) release. Analysis of the signal pathway showed that TMD23 activated Akt. Inhibition of phosphatidylinositol-3 kinase-Akt blocked the effects of TMD23 on chemotactic motility, matrix metalloproteinase-9, interleukin-8, and TNF-α. In hindlimb ischemia mice, laser Doppler perfusion imaging of the ischemic limb during the 21 days after arterial ligation showed that the perfusion recovered best with intraperitoneal infusion of TMD23 plus local injection of early EPCs, followed by either infusion of TMD23 or injection of the cells. Animals without either treatment had the worst results. Animals treated with TMD23 also had lower circulating and tissue levels of TNF-α. CONCLUSION: TM is expressed and released by human circulating EPCs. Exogenous TMD23 enhances the angiogenic potential of early EPCs in vitro through activation of phosphatidylinositol-3 kinase-Akt pathway. Coadministration of TMD23 plus early EPCs augments therapeutic angiogenesis of the EPCs in ischemic tissues.

Fluorescent gold nanoclusters as a biocompatible marker for in vitro and in vivo tracking of endothelial cells.

We have been investigating the fluorescent property and biocompatibility of novel fluorescent gold nanoclusters (FANC) in human aortic endothelial cells (HAEC) and endothelial progenitor cells (EPC). FANC (50-1000 nmol/L) was delivered into cells via the liposome complex. The fluorescence lasted for at least 28 days with a half-life of 9 days in vitro. Examination of 12 transcripts regulating the essential function of endothelial cells after a 72 h delivery showed that only the vascular cell adhesion molecule 1 and the vascular endothelial cadherin were down-regulated at high concentration (500 nmol/L). In addition, no activation of caspase 3 or proliferating cell nuclear antigens was detected. 3-[4,5-Dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide (MTT) assay demonstrated that, unlike the markedly suppressed viability in cells treated with quantum dots, FANC had minimal effect on the viability, unless above 500 nmol/L, at which level a minor reduction of viability mainly caused by liposome was found. Tube formation assay showed no impaired angiogenesis in the EPC treated with FANC. In vivo study using hindlimb ischemic mice with an intramuscular injection of FANC-labeled human EPC showed that the cells preserved an angiogenic potential and exhibited traceable signals after 21 days. These findings demonstrated that FANC is a promising biocompatible fluorescent probe.

Effects of carbenoxolone on flow-mediated vasodilatation in healthy adults.

Gap junctions play a key role in maintaining the functional integrity of the vascular wall. Using carbenoxolone (CBX) as a gap junction blocker, we aimed to assess the contribution of gap junctions in the vascular wall to flow-mediated vasodilatation (FMD) in healthy adults. Percentage FMD (%FMD) and circulating vasoactive molecules/activity, including atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), aldosterone, cortisol, plasma renin activity (PRA), and endothelin (ET-1), were measured in 25 healthy volunteers (mean age: 30.1 ± 5.4 yr; 14 males) before and after oral administration of CBX (100 mg). %FMD decreased after ingestion of CBX (9.71 ± 3.1 vs. 3.40 ± 2.0%; P < 0.0001). The levels of ANP, BNP, cortisol, and ET-1 remained stationary, while both PRA and aldosterone decreased (P < 0.005) after CBX ingestion. Blood pressure and heart rate were minimally changed by CBX. Inhibition of gap junctional communication by CBX impairs FMD in healthy persons, suggesting that physiologically, vascular gap junctions participate in the maintenance of FMD. CBX does not induce the release of vasoconstricting molecules or enhance vasoconstriction, suggesting that inhibition of gap junctional communication by CBX underlies the impairment of FMD. Therefore, administering CBX in FMD examination can be a way to follow the effect of gap junctions on endothelial function, but further work remains to verify the specificity of CBX effect.

The severity of Fatty liver disease relating to metabolic abnormalities independently predicts coronary calcification.

Background. Nonalcoholic fatty liver disease (NAFLD) is one of the metabolic disorders presented in liver. The relationship between severity of NAFLD and coronary atherosclerotic burden remains largely unknown. Methods and Materials. We analyzed subjects undergoing coronary calcium score evaluation by computed tomography (MDCT) and fatty liver assessment using abdominal ultrasonography. Framingham risk score (FRS) and metabolic risk score (MRS) were obtained in all subjects. A graded, semiquantitative score was established to quantify the severity of NAFLD. Multivariate logistic regression analysis was used to depict the association between NAFLD and calcium score. Results. Of all, 342 participants (female: 22.5%, mean age: 48.7 ± 7.0 years) met the sufficient information rendering detailed analysis. The severity of NAFLD was positively associated with MRS (X(2) = 6.12, trend P < 0.001) and FRS (X(2) = 5.88, trend P < 0.001). After multivariable adjustment for clinical variables and life styles, the existence of moderate to severe NAFLD was independently associated with abnormal calcium score (P < 0.05). Conclusion. The severity of NAFLD correlated well with metabolic abnormality and was independently predict coronary calcification beyond clinical factors. Our data suggests that NAFLD based on ultrasonogram could positively reflect the burden of coronary calcification.

Ultrasonic microbubble-mediated gene delivery causes phenotypic changes of human aortic endothelial cells.

Ultrasound, in combination with microbubbles, serves as a feasible nonviral method in vascular gene delivery. However, the effects of ultrasonic microbubble transfection (UMT) on vascular endothelial cells remained unclear. We therefore investigated whether UMT itself causes phenotypic changes of the human aortic endothelial cells (HAEC) in vitro. HAEC were cultured with solution containing luciferase reporter gene and microbubbles followed by exposure to ultrasound of selected parameters. Thereafter, the proliferation and migration activities of HAEC were investigated. Real-time RT-PCR and/or western blotting were performed to assess expression profile of HAEC, including growth-related factors (vascular endothelial growth factor, fins-like tyrosine kinase-1 [Flt-1] and kinase insert domain-containing receptor [KDR]), coagulatory factor (von Willebrand factor), vasodilatory enzyme (endothelial nitric oxide synthase), gap junctional protein connexin43 and adhesion molecules (P-selectin, intercellular adhesion molecule 1 and vascular cell adhesion molecule 1). The results showed that in conditions where UMT lead to expression of luciferase, proliferation capacity is enhanced (p<0.001), partly attributable to the effect of ultrasound (p<0.05), after excluding the effect of contact inhibition. In addition, the expression of KDR and Flt-1 were found increased at either the mRNA level, protein level, or both (p<0.05). Other markers did not have significant changes (all p>0.2). Similarly, the migration capacity was minimally changed (p>0.3). In conclusion, UMT causes phenotypic changes of HAEC by enhancing proliferation and upregulating KDR and Flt-1, while possesses no obvious adverse effect on viable transfected cells. Further investigation is required to clarify the impact of these changes by UMT in vivo.

C-reactive protein, sodium azide, and endothelial connexin43 gap junctions.

We investigated the effect of C-reactive protein (CRP) and sodium azide (NaN(3)) on endothelial Cx43 gap junctions. Human aortic endothelial cells (HAEC) were treated with (a) detoxified CRP, (b) detoxified dialyzed CRP, (c) detoxified dialyzed CRP plus NaN(3), (d) NaN(3), or (e) dialyzed NaN(3). The concentration of CRP in all preparations was fixed to 25 microg/ml and that of NaN(3) in the preparations of (c) to (e) was equivalent to that contained in the 25 microg/ml CRP purchased commercially. The results showed that both the expression of Cx43 protein and gap junctional communication function post-48-h incubation were reduced and inhibited by the detoxified CRP, NaN(3), or detoxified dialyzed CRP plus NaN(3), but not by the detoxified dialyzed CRP or dialyzed NaN(3). Reverse transcription-polymerase chain reaction analysis of cells treated for 72 h also showed a pattern of transcriptional regulation essentially the same as that for the proteins. We concluded that CRP does not have a significant effect on Cx43 gap junctions of HAEC, but NaN(3) inhibited the viability of cells and downregulate their junctions.

Endothelial connexins are down-regulated by atherogenic factors.

Connexins are single polypeptides that assemble to form paired connexon hexamers participating in gap-junctional intercellular communication. In addition, unpaired connexons at cell membrane also act as channels connecting cytosols and extracellular space. These channels' properties plus other unique functions of connexins give the molecules significant roles in endothelial cells, which mainly express connexin43 (Cx43), Cx40, and Cx37. In vitro studies have shown that expression of endothelial connexins are regulated by both physiological and pathological factors, a majority of which are involved in atherogenesis. In vascular disorders, endothelial connexins are differentially regulated. However, down-regulation of gap junctions is a common phenomenon. These findings suggest that reduced expression of endothelial gap junctions is a potential indicator of endothelial dysfunction and warrant investigators to explore the molecular mechanisms as well as therapeutic implications.

Activation of endothelial cells to pathological status by down-regulation of connexin43.

AIMS: We investigated the effects of connexin43 (Cx43) down-regulation on endothelial function. METHODS AND RESULTS: We used two different sequences of Cx43-specific small interference RNA (siRNA) to reduce de novo synthesis of Cx43 in human aortic endothelial cells and then examined the expression profiles, proliferation activity and viability, and angiogenic potential. The involvement of mitogen-activated protein kinase signalling pathways was analysed. In parallel, the effect of inhibition of gap-junctional communication by connexin-mimetic peptides was evaluated. During the down-regulation of Cx43 by the siRNA, the cells exhibited impaired gap-junctional communication, proliferation, viability, and angiogenic potential. In addition, plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor were up-regulated. Furthermore, c-jun N-terminal kinase (JNK) and its downstream target c-jun were activated, while caspase-3, p38, and extracellular signal-regulated kinase remained unchanged. Inhibition of JNK by SP600125 blocked the siRNA-induced increased expression of PAI-1 and partially recovered the impaired angiogenic potential. Short-term inhibition of Cx43 channels by connexin-mimetic peptides did not activate JNK. CONCLUSION: Down-regulation of Cx43 inhibits gap-junctional communication and activates endothelial cells to pathological status, as characterized by up-regulation of coagulatory molecules and impairment of proliferation, viability, and angiogenesis. The processes are associated with activation of JNK signalling pathways and rectified by inhibition of the activation. These results suggest that inadequate expression of Cx43 per se impairs endothelial function by the activation of stress-activated protein kinase.

Diabetes reduces aortic endothelial gap junctions in ApoE-deficient mice: simvastatin exacerbates the reduction.

We examined the endothelial gap junctions in diabetic hyperlipidemic mice. Male apolipoprotein E (apoE)-deficient mice were made diabetic by streptozotocin. Three weeks later, the animals were treated with simvastatin for 2 weeks. The expression of aortic gap junctions in the non-diabetic (n=10), untreated diabetic (n=10), and simvastatin-treated diabetic animals (n=6) was analyzed. There was a >4-fold increase in serum cholesterol level and >50% increase in plaque areas in the diabetic mice, regardless of simvastatin treatment. Western blotting of aortae showed reduced expression of connexin37 (Cx37) and Cx40 in the diabetic mice, which were further decreased in the simvastatin-treated diabetic mice. Immunoconfocal microscopy showed that endothelial gap junctions made of Cx37 and Cx40 were both reduced in the untreated diabetic mice compared with the non-diabetic mice (decrease: Cx37, 41%; Cx40, 42%; both p<0.01). The reduction was greater in the simvastatin-treated mice (decrease in treated diabetic vs non-diabetic: Cx37, 61%; Cx40, 79%; both p<0.01; decrease in treated diabetic vs untreated diabetic: Cx37, 34%; Cx40, 63%; both p<0.01). Cx37 and Cx40 were decreased in the endothelium of plaque surface. Cx43 appeared in the medial layer and inner layer of the intima. All three connexins were rarely expressed in monocytes/macrophages inside the plaques. In conclusion, in apoE-deficient mice, streptozotocin-induced diabetes is associated with downregulation of endothelial Cx37 and Cx40 gap junctions. Short-term treatment with simvastatin exacerbates the downregulation.

High triglyceride level is associated with severe coronary artery disease in hypertensive subjects.

BACKGROUND: The contribution of triglycerides (TG) to the extent of coronary artery disease (CAD) in hypertensive patients remained unclear. METHODS: Consecutive 821 (aged 64.5+/-11.5 years, 482 males) hypertensive patients undergoing coronary angiography were included. The relationship of TG levels (<150 vs. > or =150 mg/dl) to the extent of CAD in all patients was examined by multiple logistic regression, adjusting for other CAD risk factors. In the lipid group, low levels of HDL were also adjusted. RESULTS: Higher levels of TG were found in subjects with severe CAD compared to those with no or minimal CAD. The adjusted odds ratios for high levels of TG in the severe CAD subgroup versus the no or minimal CAD subgroup were 5.20 (95% CI, 3.13 to 8.63) in all patients and 7.51 (95% CI, 3.19 to 17.65) in the lipid group. CONCLUSIONS: High levels of TG are strong clinical markers of greater extent of CAD in hypertensive subjects undergoing coronary angiography. The results may have clinical relevance for physicians in therapeutic decision making.

Aortic dissection in the elderly.

To analyze the characteristics of aortic dissection in the elderly, we reviewed 168 cases from January 1999 to September 2005 in a medical center in Taiwan. Fifty-six cases were suitable for enrollment in our study. Of these, 44 (79%) were male and 12 (21%) were female; ages ranged from 29 to 92 years, with a mean of 61 +/- 11.75 years. We defined elderly as age >/= 65 years. There was no obvious discrepancy between age and types of aortic dissections involved (p = 0.726). The elderly had the lower mean systolic blood pressure (166.4 mm Hg) upon arrival at the Emergency Department (p = 0.002). Presentation to the Emergency Department with chest pain or chest tightness was more commonly seen in the elderly (66.7%) (p = 0.042). The mean hospital stay was 12.6 +/- 0.5 days, and it was longer in the elderly group (12.96 days) (p = 0.009). Otherwise, the mortality rate was 6.7% +/- 3.6%. We found a lower mortality rate in the elderly than in the younger group (4% vs. 9%, respectively; p = 0.008).

Endothelial gap junctions are down-regulated by arsenic trioxide.

We investigated the effect of As(2)O(3), an anti-cancer drug, on endothelial gap junctions. Human aortic endothelial cells (HAEC) were treated with As(2)O(3) at 1, 10, 100, and 1000 ng/ml and the cells were examined to evaluate the expression of connexin43 (Cx43) and to assess gap-junction communication. Endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) were measured to assess for endothelial dysfunction. Male Sprague-Dawley rats were given intravenous As(2)O(3) (200 mug/kg/day) or saline for 4 weeks, after which aortic endothelial gap junctions, eNOS, and circulating NO levels were evaluated. We found that HAEC Cx43 transcripts and gap junctions were reduced and gap-junction communication was attenuated by As(2)O(3). This decrease of Cx43 gap junctions was prevented by the addition of protease inhibitors. At a dose of 100 ng/ml of As(2)O(3), eNOS was reduced at 48 h, but NO was markedly reduced by 1 h. In animals treated with As(2)O(3), endothelial gap junctions comprising Cx37, Cx40, or Cx43 were all reduced in amount, while eNOS and circulating NO levels remained unchanged. In both in vitro and in vivo rat experiments, endothelial gap junctions were consistently reduced by As(2)O(3), unlike the response of eNOS and NO, which were decreased in cells but not in the rat aortic endothelium. The reduction in Cx43 involved both down-regulation at the transcriptional level and increased degradation. These findings indicate that gap-junction communication in the vascular endothelium is inhibited by treatment with As(2)O(3).

Silent and huge left ventricular pseudoaneurysm with left atrial compression: dedicated spatial resolution and geometry by 3-dimensional echocardiography.

An 83-year-old man with acute inferior wall myocardial infarction underwent successful percutaneous coronary intervention for right coronary artery. Subsequent echocardiography 3 days later showed an incidental huge cardiac chamber compressing left atrium. The chamber was found to have a narrow neck connecting with left ventricle, suggestive of a pseudoaneurysm. Real-time 3-dimensional echocardiography could clearly demonstrate the spatial relationship between pseudoaneurysm and corresponding cardiac chambers, and its precise location and the orifice of pseudoaneurysm. A myocardial break-out point resembling a bird beak with a flap could also be clearly seen and quantified by real-time 3-dimensional echocardiography. This patient underwent surgical resection and the serial follow-up remained uneventful.