Effect of Shensong Yangxin on the Progression of Paroxysmal Atrial Fibrillation is Correlated with Regulation of Autonomic Nerve Activity

BACKGROUND

Shensong Yangxin (SSYX), a traditional Chinese herbal medicine, has long been used clinically to treat arrhythmias in China. However, the mechanism of SSYX on atrial fibrillation (AF) is unknown. In this study, we tested the hypothesis that the effect of SSYX on the progression of paroxysmal AF is correlated with the regulation of autonomic nerve activity.

METHODS

Eighteen mongrel dogs were randomly divided into control group (n = 6), pacing group (n = 6), and pacing + SSYX group (n = 6). The control group was implanted with pacemakers without pacing; the pacing group was implanted with pacemakers with long-term intermittent atrial pacing; the pacing + SSYX group underwent long-term intermittent atrial pacing and SSYX oral administration.

RESULTS

Compared to the pacing group, the parameters of heart rate variability were lower after 8 weeks in the pacing + SSYX group (low-frequency [LF] component: 20.85 ± 3.14 vs. 15.3 ± 1.89 ms 2 , P = 0.004; LF component/high-frequency component: 1.34 ± 0.33 vs. 0.77 ± 0.15, P < 0.001). The atrial effective refractory period (AERP) was shorter and the dispersion of the AERP was higher after 8 weeks in the pacing group, while the changes were suppressed by SSYX intake. The dogs in the pacing group had more episodes and longer durations of AF than that in the pacing + SSYX group. SSYX markedly inhibited the increase in sympathetic nerves and upregulation of tumor necrosis factor-alpha and interleukin-6 expression in the pacing + SSYX group. Furthermore, SSYX suppressed the decrease of acetylcholine and α7 nicotinic acetylcholine receptor protein induced by long-term intermittent atrial pacing.

CONCLUSIONS

SSYX substantially prevents atrial electrical remodeling and the progression of AF. These effects of SSYX may have association with regulating the imbalance of autonomic nerve activity and the cholinergic anti-inflammatory pathway.

Neuronal Nav1.8 Channels as a Novel Therapeutic Target of Acute Atrial Fibrillation Prevention

BACKGROUND

Ganglionated plexus have been developed as additional ablation targets to improve the outcome of atrial fibrillation (AF) besides pulmonary vein isolation. Recent studies implicated an intimate relationship between neuronal sodium channel Nav1.8 (encoded by SCN10A) and AF. The underlying mechanism between Nav1.8 and AF remains unclear. This study aimed to determine the role of Nav1.8 in cardiac electrophysiology in an acute AF model and explore possible therapeutic targets.

METHODS AND RESULTS

Immunohistochemical study was used on canine cardiac ganglionated plexus. Both Nav1.5 and Nav1.8 were expressed in ganglionated plexus with canonical neuronal markers. Sixteen canines were randomly administered either saline or the Nav1.8 blocker A-803467. Electrophysiological study was compared between the 2 groups before and after 6-hour rapid atrial pacing. Compared with the control group, administration of A-803467 decreased the incidence of AF (87.5% versus 25.0%, P<0.05), shortened AF duration, and prolonged AF cycle length. A-803467 also significantly suppressed the decrease in the effective refractory period and the increase in effective refractory period dispersion and cumulative window of vulnerability caused by rapid atrial pacing in all recording sites. Patch clamp study was performed under 100 nmol/L A-803467 in TSA201 cells cotransfected with SCN10A-WT, SCN5A-WT, and SCN3B-WT. INa,P was reduced by 45.34% at -35 mV, and INa,L by 68.57% at -20 mV. Evident fast inactivation, slow recovery, and use-dependent block were also discovered after applying the drug.

CONCLUSIONS

Our study demonstrates that Nav1.8 could exert its effect on electrophysiological characteristics through cardiac ganglionated plexus. It indicates that Nav1.8 is a novel target in understanding cardiac electrophysiology and SCN10A-related arrhythmias.

TBX18 gene induces adipose-derived stem cells to differentiate into pacemaker-like cells in the myocardial microenvironment

T-box 18 (TBX18) plays a crucial role in the formation and development of the head of the sinoatrial node. The objective of this study was to induce adipose-derived stem cells (ADSCs) to produce pacemaker-like cells by transfection with the TBX18 gene. A recombinant adenovirus vector carrying the human TBX18 gene was constructed to transfect ADSCs. The ADSCs transfected with TBX18 were considered the TBX18-ADSCs. The control group was the GFP-ADSCs. The transfected cells were co-cultured with neonatal rat ventricular cardiomyocytes (NRVMs). The results showed that the mRNA expression of TBX18 in TBX18-ADSCs was significantly higher than in the control group after 48 h and 7 days. After 7 days of co-culturing with NRVMs, there was no significant difference in the expression of the myocardial marker cardiac troponin I (cTnI) between the two groups. RT-qPCR and western blot analysis showed that the expression of HCN4 was higher in the TBX18-ADSCs than in the GFP-ADSCs. The I_f current was detected using the whole cell patch clamp technique and was blocked by the specific blocker CsCl. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSCMs) showed approximately twice the current density compared with the ADSCs. Our study indicated that the TBX18 gene induces ADSCs to differentiate into pacemaker-like cells in the cardiac microenvironment. Although further experiments are required in order to assess safety and efficacy prior to implementation in clinical practice, this technique may provide new avenues for the clinical therapy of bradycardia.

Activin A stimulates the proliferation and differentiation of cardiac fibroblasts via the ERK1/2 and p38-MAPK pathways

Activin A is a key regulator of cardiac fibrosis. However, little is known about the mechanisms by which it contributes to cardiac fibrosis. Our study explored the effects of activin A on proliferation and differentiation of adult rat cardiac fibroblasts (CFs) via the activin A receptor, activin receptor-like kinase 4 (ALK4). CF proliferation was measured by CCK8 and EdU assays, while differentiation, fibrosis and signaling were measured by western blot analysis of α-smooth muscle actin, collagen type I, phosphorylated extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (p38-MAPK) expression. Activin A levels were measured by ELISA and western blot analysis. We demonstrated that CFs express activin A and its expression was significantly enhanced by angiotensin II (Ang II), but follistatin (activin A inhibitor) significantly reversed Ang II-induced activin A upregulation, CF proliferation, differentiation, collagen type I expression as well as ERK1/2 and p38-MAPK pathways activation. Conversely, recombinant activin A largely increased these parameters in both the presence and absence of Ang II. Interestingly, p38-MAPK (SB203580) and ALK4 (SB431542) inhibitors significantly reduced all activin A-mediated responses; however, an ERK1/2 inhibitor (PD98059) could only significantly reduce CF proliferation and collagen type I expression but not differentiation. Importantly, the most significant effects were observed in the presence vs. absence of Ang II. Thus, activin A promotes basal and Ang II-induced CF proliferation and differentiation via ALK4, and the effects are partly mediated through the ERK1/2 and p38-MAPK pathways. These data suggest that activin A is a potential therapeutic target for cardiac fibrosis.

Relationship between brain activity and voiding patterns in healthy preterm neonates

INTRODUCTION

It remains controversial as to whether the brain affects voiding control in preterm newborns. Constant bladder volume has previously been thought to induce bladder voiding in neonates, with no influence from the brain. Lately, there has been distinct evidence for an existing connection between the central nervous system and bladder voiding in preterm infants, as the voiding reflex arouses neonatal children. Video electroencephalography (EEG) is useful for recording bioelectrical activity of the cerebral cortex and exploring its relationship with voiding patterns in preterm neonates.

OBJECTIVE

The objective was to investigate the relationship between voiding patterns and brain activity in healthy preterm neonates by using video-EEG.

STUDY DESIGN

Forty-seven healthy preterm neonates (16 females) with a mean postconceptional age (PCA) of 34.1 ± 1.8 weeks were divided according to PCA into three groups: Group I (31-33 weeks, n = 13); Group II (33-35 weeks, n = 14); and Group III (35-37 weeks, n = 20). Video-EEG data from eight cortical regions were recorded from 08:00-12:00, along with 4-hour free voiding patterns and status at voiding (awake/sleep).

RESULTS

In Group I, the voiding frequency (VF) was significantly higher and the voiding volume (VV) was significantly lower than in the other groups. There were no significant differences in bladder capacity (BC), bladder capacity/birth weight (BC/BW), postvoiding residual/bladder capacity (PVR/BC), or urinary flow rate (UFR) among the three groups. The Fp1-T3 and Fp2-T4 lead amplitudes significantly differed in Group I and Group II at 5 s before (pre-5), during, and after voiding (post-5). The Fp2-C4 total and theta band lead amplitudes significantly differed across all urination states among the groups. There were no significant differences in electroencephalography frequency among the groups in any urination state.

DISCUSSION

There were no significant differences in BC, BC/BW, PVR/BC, or UFR among the three groups, indicating slow bladder function development in preterm neonates. In this study, the EEG amplitude changed in certain pairs of electrodes. These changes might indicate the degree of bladder sensor maturation along with an increasing PCA. This study further suggests that the brain changes in preterm neonates during quiet sleep voiding prominently occur in the right prefrontal cortex and central region.

CONCLUSIONS

In preterm neonates, bladder voiding during quiet sleep was accompanied by cortical arousal that might have emanated from a lower center.

Caspase-1 mediates hyperlipidemia-weakened progenitor cell vessel repair

Caspase-1 activation senses metabolic danger-associated molecular patterns (DAMPs) and mediates the initiation of inflammation in endothelial cells. Here, we examined whether the caspase-1 pathway is responsible for sensing hyperlipidemia as a DAMP in bone marrow (BM)-derived Stem cell antigen-1 positive (Sca-(1+)) stem/progenitor cells and weakening their angiogenic ability. Using biochemical methods, gene knockout, cell therapy and myocardial infarction (MI) models, we had the following findings: 1) Hyperlipidemia induces caspase-1 activity in mouse Sca-(1+) progenitor cells in vivo; 2) Caspase-1 contributes to hyperlipidemia-induced modulation of vascular cell death-related gene expression in vivo; 3) Injection of Sca-1+ progenitor cells from caspase-1(-/-) mice improves endothelial capillary density in heart and decreases cardiomyocyte death in a mouse model of MI; and 4) Caspase-1(-/-) Sca-(1+) progenitor cell therapy improves mouse cardiac function after MI. Our results provide insight on how hyperlipidemia activates caspase-1 in Sca-(1+) progenitor cells, which subsequently weakens Sca-(1+) progenitor cell repair of vasculature injury. These results demonstrate the therapeutic potential of caspase-1 inhibition in improving progenitor cell therapy for MI.

Dietary inclusion level and time effects of taurine on broiler performance, meat quality, oxidative status and muscle taurine content

Two experiments were conducted to investigate the effect of taurine on growth performance, meat quality, oxidative status and muscle taurine content in broilers. In Experiment 1, 50 one-day-old male Cobb chicks were given a diet supplemented with 0, 0.125, 0.50, 2.00 or 8.00 g/kg taurine from 1 to 42 d of age. In Experiment 2, 80 22-d-old male Cobb chicks were given a diet supplemented with 4.00 g/kg taurine for 0, 1, 2 or 3 weeks. Taurine contents of thigh and breast muscle increased linearly with increasing dietary taurine. Taurine supplementation for 1, 2 and 3 weeks significantly increased the taurine content of breast muscle. The taurine contents of liver and thigh meat were significantly increased by taurine supplementation for 3 weeks. The taurine contents of thigh and breast meat from broilers given a diet supplemented with 4 g/kg taurine for 3 weeks increased to 1.89 times the concentrations of the control group. There were no detrimental effects on growth performance, breast or thigh muscle yield, pH value or drip-water loss, and taurine supplementation did not affect the serum carbonyl content. Serum malondialdehyde concentration was significantly decreased by taurine supplementation for 1, 2 or 3 weeks.

Expression of ghrelin and its receptor in rats after coronary artery ligation

Ghrelin is a novel growth hormone-releasing peptide, which has been shown to exert beneficial effects on cardiac function and ventricular remodeling. The present study aimed to investigate the expression of ghrelin and the growth hormone (GH) secretagogue receptor 1a (GHSR-1a), and the association with cardiac remodeling in rats with myocardial infarction (MI). Twenty-four hours after ligation of the anterior descending artery (LAD), adult male Sprague-Dawley rats were randomized to 3 d, 7 d and 28 d group. Sham animals underwent thoracotomy and pericardiotomy, but not LAD ligation. Expression of both ghrelin and GHSR-1a was assessed by means of immunohistochemistry and real-time PCR. Plasma ghrelin levels were measured by ELISA kit. In addition, cardiac remodeling was assessed by echocardiographic and hemodynamic measurements. Plasma and cardiac expression of ghrelin decreased on days 3, 7 and 28 compared with the sham group (P<0.05). In contrast the GHSR-1a mRNA levels increased during the same days (P<0.05). Decreased positive immunoreaction for ghrelin and increased positive GHSR-1a were also observed in the infarcted heart. Interestingly, plasma ghrelin correlated negatively with left ventricular end-diastolic pressure (r=-0.59, P=0.002) and left ventricular end-diastolic dimension (r=-0.73, P<0.01). The ghrelin system may play an important role regulating cardiac remodeling after MI and present as a potential significant target for pharmacological modulation and treating cardiac remodeling.

Potential new role of the GHSR-1a-mediated signaling pathway in cardiac remodeling after myocardial infarction (Review)

The gastrointestinal hormone ghrelin has important cardiovascular protective effects, however, its specific mechanisms are not yet completely understood. Recent studies have shown that the ghrelin receptor, growth hormone secretagogue receptor type 1a (GHSR-1a), regulates cell proliferation, apoptosis and inflammation-related signaling pathways. In human aortic endothelial cells, ghrelin activates NO production through AMP-activated protein kinase (AMPK) and Akt activation, and these effects can be blocked by knockdown of GHSR-1a. Obese mice have been found to exhibit an increased GHSR-1a content and expression in the heart, associated with an increase in phosphatidylinositol 3-kinase (PI3K) content and an increase AKT content and phosphorylation. Furthermore, GHSR-1a expression was observed to be increased in heart failure after myocardial infarction (MI) in rats. Given such complexity in GHSR-1a signaling and crosstalk with the AMPK and PI3K/Akt signaling pathways, both of which are well-known factors involved in cardiac remodeling after MI, we speculate that GHSR-1a signaling may play a regulatory role in cardiac protection and hope to identify new drugs targets. However, to date, no direct association between GHSR-1a and cardiac remodeling has been found. Therefore, further studies are required.

A novel GATA5 loss-of-function mutation underlies lone atrial fibrillation

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is associated with significantly increased morbidity and mortality. Cumulative evidence highlights the importance of genetic defects in the pathogenesis of AF. However, AF is of remarkable heterogeneity and the genetic determinants of AF in a vast majority of patients remain illusive. In this study, the coding exons and splice junctions of the GATA5 gene, which encodes a zinc-finger transcription factor essential for normal cardiogenesis, were sequenced in 118 unrelated patients with lone AF. The available relatives of the index patient carrying an identified mutation and 200 unrelated ethnically-matched healthy individuals used as controls were genotyped. The functional effect of the mutant GATA5 was characterized in contrast to its wild-type counterpart using a luciferase reporter assay system. As a result, a novel heterozygous GATA5 mutation, p.W200G, was identified in a family with AF inherited as an autosomal dominant trait. The mutation was absent in 200 control individuals and the altered amino acid was completely conserved evolutionarily across species. Functional analysis showed that the mutation of GATA5 was associated with a significantly decreased transcriptional activity. These findings provide novel insight into the molecular mechanism involved in AF, suggesting potential implications for the early prophylaxis and gene-specific therapy of AF.

Myocardial angiogenesis after chronic ghrelin treatment in a rat myocardial infarction model

Ghrelin has a protective role in a rat model of myocardial infarction (MI), but the underlying mechanism is not clear. Here, we investigated the effects of ghrelin treatment on angiogenesis in an experimental rat MI model. Adult male Sprague-Dawley rats were subjected to MI by ligating the anterior descending coronary artery. The rats were then treated with a subcutaneous injection of ghrelin (100 μg/kg) or saline (control group) for 4 weeks. Sham animals underwent thoracotomy and pericardiotomy, but not LAD ligation. At 28 days after ligation, the ghrelin treatment group showed a higher density of α-SMA positive vessels than the saline treatment MI group in myocardial infarct (6±2.1/mm(2) vs 4±1.8/mm(2), P<0.05) and peri-infarct zones (25±9.5/mm(2) vs 15±5.7/mm(2), P<0.05). RT-PCR and western-blot analyses showed that ghrelin significantly increased vascular endothelial growth factor (VEGF) expression in the peri-infarct zone compared with the control group. Moreover, there was a two-fold increase of Bcl-2 and a 3.5-fold reduction of the Bax protein in the ghrelin-treated MI group compared to the saline treatment MI group. Taken together, ghrelin could induce angiogenesis in rats after MI, the process that may be associated with the enhancement of VEGF and an anti-apoptosis effect.

A cross-sectional survey on the prevalence of anxiety symptoms in Chinese patients with premature ventricular contractions without structural heart disease

BACKGROUND

Anxiety appears to be more common in patients with coronary artery disease (CHD) than in the general population, and anxiety symptoms may precede onset of CHD and play an important role in development of CHD. Little is known about the prevalence of anxiety symptoms in Chinese patients with premature ventricular contractions (PVCs). Our objective was to study anxiety symptoms and potential risk factors in a Chinese population with PVCs but without structural heart disease.

METHODS

The Zung self-rating anxiety scale (ZSAS) was used to assess anxiety symptoms. Correlation between anxiety symptoms and socio-demographics and medical factors were analyzed by Logistic regression.

RESULTS

Of 1144 patients with PVCs (487 males and 657 females), age (53 ± 23) years old, disease duration 1 month to 24 years, a total of 381 (33.3%) patients were categorized as having anxiety symptoms. Anxiety symptoms increased with age, low income, low education level, nationality, PVC count/24 hours, bad social support, village settlement type (P < 0.05). Multivariate Logistic regression indicated that six variables-education level, ethnic minorities, dwelling place, age, PVC count/24 hours, and social support-significantly and independently related with anxiety symptoms (P < 0.05).

CONCLUSIONS

In the Chinese population, anxiety symptoms in subjects with PVCs were frequent. Education level, ethnic minorities, dwelling place, age, PVC count/24 hours, and social support were independent risk factors for anxiety symptoms. Further research on the relationship between PVCs and anxiety symptoms in China is necessary.

P75 neurotrophin receptor is a regulatory factor in sudden cardiac death with myocardial infarction

Sudden cardiac death (SCD) is a major cause of morbidity and mortality in patients with coronary artery diseases and myocardial infarction (MI). Sympathetic stimulation and sympathetic neural remodeling are important in the generation of SCD in diseased heart. The balance of nerve growth factor (NGF) and semaphoring 3A determines the sympathetic innervation patterning. Recently studies showed that P75 neurotrophin receptor (P75 NTR) is the main receptor for NGF mediates sympathetic hyperinnervation in the heart, and also interacts with semaphoring 3A. Sympathetic axons lacking P75 NTR are more sensitive to semaphoring 3A in vitro than control neurons, resulting in decreased sympathetic innervation in the left ventricular subendocardium. P75 NTR(-/-) mice had increased sympathetic heterogeneity and more spontaneous ventricular arrhythmias. Based on current studies, we present a hypothesis that P75 NTR plays an important regulatory role in sudden cardiac after myocardial infarction and hope to find new therapeutic target for SCD.

Ablation of atrial tachycardia occurring after catheter ablation of atrial fibrillation in patients with corrected rheumatic valve disease

OBJECTIVE

The purpose of this study is to investigate the mechanism and the effectiveness of ablation of atrial tachycardia (AT) recurring after atrial fibrillation (AF) ablation in patients with rheumatic valvular disease (RVD) and mitral valve prosthesis.

METHODS

Twenty-eight consecutive patients with RVD and mitral valve prosthesis and a 1:2 matched control group (n = 56) without RVD underwent reablation for recurrent AT after catheter ablation of long-standing persistent AF.

RESULTS

Macro- or localized reentrant ATs were identified in 47 (87 %) of 54 ATs from RVD group and in 65 (78.3 %) of 83 ATs from control. There were more average ATs per patient in the RVD group than in the control (1.9 ± 0.6 vs.1.5 ± 0.6, P = 0.002). The proportion of patients having ≥2 ATs was significantly higher in the RVD group than in the control (78.6 vs.41.1 %, P = 0.001). In the RVD group, ATs were successfully ablated in 44 (81.5 %) of 54 ATs and terminated in 18 (64.3 %) of 28 patients. In the control, ATs were successfully ablated in 72 (86.7 %) of 83 ATs and terminated in 45 (80.4 %) of 56 patients, P = 0.54 and 0.10, respectively. After a mean follow-up of 13 months, 16 patients (57.1 %) from the RVD group and 45 patients (80.4 %) from the control were free of further recurrence, P = 0.02.

CONCLUSIONS

Macro- or localized reentries were the predominant type of recurrent AT after long-standing persistent AF ablation in both the RVD and the control groups. Compared with patients without RVD, patients with RVD had more average number of ATs and had higher probability of further recurrence despite the similar acute effectiveness of reablation.

Serum uric acid levels correlate with atrial fibrillation in patients with chronic systolic heart failure

BACKGROUND

Studies have shown that increased levels of serum uric acid (SUA) are associated with atrial fibrillation (AF). However, less is known about the prognostic value of SUA levels for AF in patients with chronic heart failure (CHF). The aim of the study was to examine the prognostic value of SUA levels for AF in patients with CHF.

METHODS

Sixteen thousand six hundred and eighty-one patients diagnosed with CHF from 12 hospitals were analyzed. Patients were categorized into AF group and non-AF group, death group, and survival group according to the results of the patients' medical records and follow-up. Univariate and multivariate Cox proportional hazards analyses were performed to examine the risk of AF. The sensitivity and specificity of SUA level in predicting the prognosis were examined by multivariate Cox models and receiver operating characteristic (ROC) curves.

RESULTS

The results of univariate predictors in overall patients showed that the higher SUA level was associated with AF. SUA level (HR, 1.084; 95%CI, 1.017 - 1.144; P < 0.001), diuretics (HR, 1.549; 95%CI, 1.246 - 1.854; P < 0.001), and New York Heart Association (NYHA) (HR, 1.237; 95%CI, 1.168 - 1.306; P < 0.001) function class were the independent risk factors for AF. The sensitivity and specificity of the models were 29.6% and 83.8% respectively for predicting AF. When SUA level was added to these models, it remained significant (Wald c(2), 1494.88; P < 0.001 for AF); 58.8% (95%CI, 57.7% - 60.0%) of the observed results were concordant with the separate model.

CONCLUSION

Higher SUA level is associated strongly with AF in patients with CHF. SUA level can increase the sensitivity and specificity in predicting AF.

First Report of Root-Knot Nematode Meloidogyne arenaria Infesting Roots of Anubias barteri in Guangdong, China

Anubias spp. are very popular aquatic plants that are native to Africa. Anubias barteri is a broadleaf Anubias and is a popular choice for aquariums because of its robust size. In China, broadleaf Anubias is usually planted in sand, with sponges around the rhizome, in small plastic baskets in aquatic plant nurseries. In December 2010, a survey of phytoparasitic nematodes was conducted in the nurseries in Guangzhou, Guangdong Province. Many second-stage juveniles of a Meloidogyne sp. were detected from the roots of A. barteri, but no root galls were found. To identify these juveniles, molecular identification was performed with PCR. The DNA sequence between CO II and l-rRNA of the mitochondrial gene of single juveniles was amplified with universal primers of Meloidogyne, #C2F3 (5'-GGTCAATGTTCAGAAATTTGTGG-3') and #1108 (5'-TACCTTTGACCAATCACGCT-3') (3). The amplified fragments were approximately 1.1 kb long and could not be digested with restrictive enzyme HinfI. The specific fragments were then sequenced. The blast search result revealed that the DNA sequence (GenBank Accession No. JQ446377) had 99 to 100% identity with submitted sequences of Meloidogyne arenaria (GenBank Accession Nos. EU364879, GQ266686, and AY635610). The other extracted juveniles were inoculated into sterile, potted, water spinach (Ipomoea aquatica) in the greenhouse to obtain more nematodes. After 40 days, root galls and female egg masses were clearly observed, and biochemical, molecular, and morphological identifications were conducted. Isoenzyme phenotype (esterase and malate dehydrogenase (MDH) patterns) and the perineal pattern of several gravid females were the same as M. arenaria (1,2), and PCR amplification of single juveniles produced identical fragments as previously found. Single egg masses were collected and juveniles were hatched out and inoculated onto 10 nematode-free plants of A. barteri in a greenhouse. After 40 days, roots of A. barteri exhibited inconspicuous small galls, and the same identification procedures were conducted as mentioned previously. Isoenzyme phenotypes, perineal patterns of adult females, and amplified fragments of single juveniles were identical to those of M. arenaria. M. arenaria is one of the most important root-knot nematodes and causes great losses in many crops around the world (2). To our knowledge, this is the first record of M. arenaria parasitizing aquatic plants of broadleaf Anubias in China and elsewhere, and A. barteri is a new host of M. arenaria. The economic importance of this nematode to A. barteri production is currently unknown. However, because A. barteri is a commercial aquatic plant, more attention should be given by producers to prevent this nematode from becoming an important pathogen. In addition, this finding is very helpful for relevant plant nematode quarantine work. References: (1) P. R. Esbenshade and A. C. Triantaphyllou. J. Nematol. 17:1, 1985. (2) R. N. Perry et al. Root-Knot Nematodes. CABI. Wallingford, UK, 2009. (3) T. O. Powers and T. S. Harris. J. Nematol. 25:1, 1993.

Effects of ghrelin on Cx43 regulation and electrical remodeling after myocardial infarction in rats

Ghrelin is a novel growth hormone-releasing peptide, which has been shown to exert beneficial effects on ventricular remodeling. In this study, we investigated whether ghrelin could decrease vulnerability to ventricular arrhythmias in rats with myocardial infarction and the possible mechanism. Twenty-four hours after ligation of the anterior descending artery, adult male Sprague-Dawley rats were randomized to ghrelin (100 μg/kg) and saline (control group) for 4 weeks. Sham animals underwent thoracotomy and pericardiotomy, but not LAD ligation. Myocardial endothelin-1 (ET-1) levels were significantly elevated in saline-treated rats at the border zone compared with sham-operated rats. Myocardial connexin43 (Cx43) expression at the border zone was significantly decreased in saline-treated infarcted rats compared with sham-operated rats. Ghrelin significantly decreased the inducibility of ventricular tachyarrhythmias compared with control group. Arrhythmias sores during programmed stimulation in saline-treated rats were significantly higher than scores in those treated with ghrelin. The electrophysiological improvement of fatal ventricular tachyarrhythmias was accompanied with increased immunofluorescence-stained Cx43, myocardial Cx43 protein and mRNA levels in ghrelin treated rats. We also shown that ghrelin significantly decreased tissue ET-1 levels at the infarcted border zone. Thus, ghrelin showed the protective effect on ventricular arrhythmias after myocardial infarction. Although the precise mechanism by which ghrelin modulates the dephosphorylation of Cx43 remains unknown, it is most likely that the ghrelin increased expression of Cx43 through the inhibition of ET-1.

[The prognostic value of etiology in patients with chronic systolic heart failure]

OBJECTIVE

To determinate the prognostic value of etiology in patients with chronic systolic heart failure (CSHF).

METHODS

Data of in-hospital patients with CSHF were investigated between 2000 and 2010 from 12 hospitals in Hubei province. All patients were followed up through telephone calls. Univariate and multivariate Cox proportional hazards analyses were then used to explore the differences in the all-cause mortality, heart failure (HF) mortality and sudden cardiac death (SCD) among patients caused by different etiologies. Kaplan-Meier curve were then constructed and Univariate and multivariate Cox regression analyses were used to select demographic and clinical variables in predicting the all-cause mortality, HF mortality and SCD in CSHF patients. Multivariate logistic models and ROC curve were developed with or without the confirmed etiology to assess the incremental additive information related to different etiologies.

RESULTS

(1) Over the median 3 (2 - 4) years follow-up program, 6453 (38.69%) patients died, including 5505 (33.00%) due to HF prognosis and 717 (4.30%) died of SCD. All-cause mortality rates accounted for 34.50%, 54.30%, 41.48% and 15.76%, with HF mortality rates as 30.11%, 44.95%, 36.25% and 13.10%. SCDs accounted 8.46%, 8.45%, 9.84% and 1.05% in patients with CHD, DCM, HHD and RHD, respectively. (2) Compared with RHD patients, the adjusted HRs for all-cause mortality were 1.554 (1.240 to 1.947; P < 0.001), 1.405 (1.119 to 1.764; P = 0.003) and 1.315 (1.147 to 1.467; P = 0.005) while the adjusted HRs and 95%CIs for HF mortality were 1.458 (1.213 - 1.751; P < 0.001), 1.763 (1.448 - 2.147; P < 0.001) and 1.281 (1.067 - 1.537; P = 0.008), in patients with CHD, DCM and HHD, respectively. There were no significant differences in CHD (HR 3.345; 95%CI, 1.291 to 8.666; P = 0.013) or HHD (HR 2.062; 95%CI, 0.794 to 5.352; P = 0.137), while only DCM (HR 4.764; 95%CI, 1.799 to 12.618; P = 0.002) remained significant in SCD despite of the multivariate adjustment. (3) Etiology increased the sensitivity and specificity of predicting models for all-cause mortality (AUC 0.839, 95%CI, 0.832 to 0.845 vs. 0.776, 95%CI, 0.768 to 0.784) and HF mortality (AUC 0.814, 95%CI, 0.806 to 0.822 vs. 0.796, 95%CI, 0.788 to 0.804) but not with SCD (AUC 0.777, 95%CI, 0.749 to 0.809 vs. 0.747, 95%CI, 0.727 to 0.766).

CONCLUSION

CSHF due to CHD, DCM and HHD carried a worse prognosis than that of RHD. Different etiologies provided significant incremental prognostic information beyond readily available clinical variables for all-cause mortality and HF mortality.

Analysis of Na(+)/Ca (2+) exchanger (NCX) function and current in murine cardiac myocytes during heart failure

Na(+)/Ca(2+) exchanger (NCX) plays important roles in cardiac electrical activity and calcium homeostasis. NCX current (I(NCX)) shows transmural gradient across left ventricle in many species. Previous studies demonstrated that NCX expression was increased and transmural gradient of I(NCX) was disrupted in failing heart, but the mechanisms underlying I(NCX) remodeling still remain unknown. In present study, we used patch clamp technique to record I(NCX) from subepicardial (EPI) myocytes and subendocardial (ENDO) myocytes isolated from sham operation (SO) mice and heart failure (HF) mice. Our results showed that I(NCX) was higher in normal EPI cells compared with that in ENDO, whatever for forward mode or reverse mode. In HF group, I(NCX) was significantly up-regulated, but EPI-ENDO difference was disrupted because of a more increase of I(NCX) in ENDO myocytes. In order to explore the molecular mechanism underlying remodeling of I(NCX) in failing heart, we detected the protein expression of NCX1 and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) by Western blot. We found that CaMKII activity was dramatically enhanced and parallel with the expression of NCX1 in failing heart. Our study demonstrated that transmural gradient of I(NCX) existed in murine left ventricle, and increased activity of CaMKII should account for I(NCX) remodeling in failing heart.

[Characteristics of in-hospital patients with chronic heart failure in Hubei province from 2000 to 2010]

OBJECTIVE

To evaluate the current status of chronic heart failure (CHF) in Hubei province and analyze the epidemiology of CHF including the general condition, etiology and pharmacological therapy.

METHODS

Data of in-hospital patients with CHF were investigated between 2000 and 2010 from 12 hospitals in Hubei Province.

INCLUSION CRITERIA

over 18 years of age, organic heart disease and with the symptom of HF including dyspnea and fatigue. Patients with a history of myocardial infarction in the prior 12 months, congenital heart disease, pericardial disease and the history of cancer were excluded.

RESULTS

(1) A total of 12 450 patients were enrolled (7166 male, 57.56%). The average age was (62.0 ± 14.5) years. Patients in the scale of age ≥ 80, 70 - 79, 60 - 69, 50 - 59, 40 - 49 and < 40 was 9.53% (1187/12 450), 30.80% (3835/12 450), 23.45% (2920/12 450), 18.81% (2342/12 450), 10.73% (1336/12 450) and 6.67% (830/12 450), respectively (P < 0.01). The NYHA class I, II, III and IV was 0.60%, 23.20%, 50.31% and 26.50%, respectively. (2) The age of patients was significant reduced from 2000 - 2003, 2004 - 2006 to 2007 - 2010 [(66.4 ± 14.1) years, (64.9 ± 14.4) years and (64.2 ± 14.8) years, P < 0.01]. (3) The major causes of CHF were hypertension (31.54%), coronary heart disease (28.24%), dilated cardiomyopathy (26.57%) and rheumatic valvular heart disease (17.49%). The most frequent etiology for CHF was rheumatic valvular heart disease in patients aged less than 40 years old, dilated cardiomyopathy in patients aged 40 - 49 and 50 - 59 years and hypertension in patients aged 60-69, 70-79 and ≥ 80 years. (4) Drug use was as follows: Digitalis (47.49%), diuretics (68.75%), ACEI (50.66%), β-blocker (44.06%) and aldosterone antagonist (53.08%). Use of digitalis (Wald χ(2) = 903.41, P < 0.01;r = 0.271, P < 0.01), diuretics (Wald χ(2) = 818.05, P < 0.01; r = 0.249, P < 0.01), aldosterone antagonists (Wald χ(2) = 76.92, P < 0.01; r = 0.091, P < 0.01) increased while the β-blocker (Wald χ(2) = 160.65, P < 0.01; r = -0.117, P < 0.01) declined in proportion to NYHA class increase.

CONCLUSIONS

The age of in-hospital patients with CHF declined in the previous 10 years. The primary etiology was hypertension for aged CHF in-hospital patients with CHF. There was big gap between guideline recommended standard therapy and current drug use for in-hospital patients with CHF in Hubei province.

ADAMTS-1 expression in rat myocardium after ischemic preconditioning: age-associated differences

BACKGROUND

It has been found that cardiac protection afforded by ischemic preconditioning (IPC) is significantly reduced in the senescent myocardium. ADAMTS-1 (a disintesrin and metalloprotease with thrombospondin type 1 motifs) has been shown to inhibit angiogenesis in a variety of in vitro and in vivo assays. The aim of this study was to investigate the age-associated differences in ADAMTS-1 protein expression in rat myocardium after ischemic preconditioning.

METHODS

Sixty-four young (4 months) and old (24 months) male Sprague-Dawley rats were randomly assigned to an IPC group (40 rats) or a sham group (rats). A model of delayed IPC was induced and rats were sacrificed and myocardial samples were harvested from the ischemic-reperfused region for immunohistochemical detection of ADAMTS-1 at serial time points after IPC. A model of myocardial infarction was produced by ligation of the left anterior descending coronary artery in additional sets of young and old rats after sham or IPC procedures, then age-associated myocardial infarction survival after IPC was calculated.

RESULTS

ADAMTS-1 expression increased significantly in old rats compared to young rats (P < 0.05). The mean densities of ADAMTS-1 protein at 0, 6, 12, and 24 hours in young-IPC group after IPC were 0.05 ± 0.01, 0.13 ± 0.03, 0.16 ± 0.04, and 0.12 ± 0.03 vs. 0.07 ± 0.03, 0.20 ± 0.03, 0.24 ± 0.05, and 0.21 ± 0.04 in old-IPC group. IPC resulted in diminished survival rates (5/35 vs. 6/14, old-IPC group vs. old-sham group, P < 0.05), reduced left ventricular fractional shortening ((13.9 ± 2.8)% vs. (18.3 ± 2.3)%, P < 0.05) and increased the myocardial infarction size ((37.9 ± 3.2)% vs. (32.8 ± 5.1)%, P < 0.05) in the older rats.

CONCLUSIONS

Cardioprotection with IPC is attenuated in the older heart. ADAMTS-1 expression induced by IPC is greater in old rats. Over-expression of anti-angiogenic factors might be a potential mechanism behind reduced protection after IPC associated with aging.

[Predictive value of QT interval dynamicity for sudden death in patients with idiopathic dilated cardiomyopathy]

OBJECTIVE

To explore the predictive value of QT interval dynamicity for sudden death in patients with idiopathic dilated cardiomyopathy (DCM).

METHODS

Fifty-five patients with DCM (DCM group) and 27 healthy subjects (Control group, Con) were enrolled. Investigations included history collection, clinical examination, echocardiography, electrocardiogram and 24 h ambulatory electrocardiogram. Following indexes were determined: left ventricle end diastolic dimension (LVEDD), left ventricle ejection fraction (LVEF), QT dispersion (QTd), SDNN, the slope of QT/RR plots of the linear regression, ventricular premature beats (VPB) and non-sustained ventricular tachycardia (NSVT). Primary end point for patients with DCM was all cause death.

RESULTS

LVEDD, QTd, VPB/24 h, NSVT/24 h, QTe/RR slope and QTp/RR slope were significantly higher while LVEF and SDNN were significantly lower in DCM group than in Con group (all P < 0.05). LVEDD, LVEF, QTd, SDNN, QTe/RR slope and QTp/RR slope were significantly different among DCM sudden death group, DCM non sudden death group and Con group (P < 0.05). LVEF, SDNN, QTe/RR slope and QTp/RR slope were significantly different between DCM sudden death and non sudden death group (P < 0.05). LVEF, QTd, VPB/24 h, QTe/RR slope and QTp/RR slope were significantly different between DCM with NSVT and DCM without NSVT group (P < 0.05). The sudden death rate of DCM patients with QTe/RR slope ≥ 0.210 was significantly higher than DCM patients with QTe/RR slope < 0.210 (54.5% vs. 21.1%, P < 0.05). Sudden death rate of QTp/RR slope ≥ 0.190 was also higher than those < 0.190 (52.2% vs. 21.9%, P < 0.05). The sudden death rate of DCM patients with both LVEF ≤ 35% and NSVT+ was 62.5%. Combining QTe/RR ≥ 0.210 with NSVT+ or LVEF ≤ 35%, the sudden death rates were 62.5% or 66.7%. Combining QTp/RR ≥ 0.190 with NSVT+ or LVEF ≤ 35%, the sudden death rates were 66.7% or 61.5%. Combining QTe/RR ≥ 0.210 or QTp/RR ≥ 0.190 with NVST+ and LVEF ≤ 35%, the sudden death rates were 77.8% or 70.0%.

CONCLUSIONS

High QT/RR slope is a risk factor for sudden death of DCM patients. QT/RR slope is a useful predictor for sudden death in DCM patients either independently or combined with NSVT or LVEF.

Atrial autonomic innervation remodelling and atrial fibrillation inducibility after epicardial ganglionic plexi ablation

AIMS

The effects of ganglionated plexi (GP) ablation on atrial fibrillation (AF) inducibility and atrial autonomic innervation remodelling have not been elucidated.

METHODS AND RESULTS

Thirteen dogs were randomly divided into sham-operated group and GP ablation group. All animals underwent a right thoracotomy at the fourth intercostal space. Atrial fibrillation inducibility was assessed by burst rapid pacing at right atrium (RA). After anterior right GP and inferior right GP ablation, AF inducibility was assessed in the GP ablation group. The animals were allowed to recover for 8 weeks, after which, AF was measured again. The levels of atrial natriuretic peptide (ANP) in blood and atrial tissues were examined by radioimmunoassay. Immunocytochemical staining of cardiac nerves was performed in tissues from the dogs. Atrial fibrillation was induced easily in the GP ablation group after 8 weeks although AF was not observed in the sham-operated group, and after instant GP ablation. Compared with that in the sham-operated group, the levels of ANP in the blood and RA increased significantly 8 weeks after GP ablation (111.4 +/- 18.2 vs. 175.1 +/- 25.9; 184.9 +/- 36.3 vs. 299.1 +/- 32.5; P < 0.05). In the GP ablation group, the density of growth-associated protein 43-positive, tyrosine hydroxylase-positive, and choline acetyltransferase-positive nerves in the RA was 821 +/- 752, 481 +/- 627, and 629 +/- 644 per mm(2), respectively, which was significantly (P < 0.01) lower than the nerve density in sham-operated tissues (2590 +/- 841, 1752 +/- 605, and 3147 +/- 886 per mm(2), respectively).

CONCLUSION

Atrial autonomic innervations remodelling may be the mechanism of induced AF after GP ablation.

[Effects of verapamil preconditioning on cardiac function in vitro and intracellular free Ca2+ and L-type calcium current in rat cardiomyocytes post ischemia-reperfusion injury]

OBJECTIVE

To investigate the influences of verapamil preconditioning on cardiac function in vitro and intracellular free Ca2+ and L-type calcium current (I(Ca-L)) in rat cardiomyocytes post ischemia-reperfusion (I/R) injury.

METHODS

The isolated rat hearts in control group (37 degrees C Tyrode solution perfusion for 30 min, n = 6), I/R group (no flow for 30 min followed 30 min reperfusion with 37 degrees C Tyrode solution, n = 7) and verapamil preconditioning group [37 degrees C Tyrode solution perfusion for 10 min, adding verapamil (20 micromol/L) to Tyrode solution and perfusion for another 30 min, followed then by 30 min no flow and 30 min reperfusion, n = 7] using Langendorff perfusion system. The fluorescence intensity of intracellular Ca2+ was detected with Fluo-3/AM loading by the laser scanning confocal microscope. The I(Ca-L) was recorded via whole-cell patch clamp technique in enzymatically dissociated single rat ventricular myocytes.

RESULTS

As expected, arrhythmias and cardiac dysfunction were shown post I/R injury. The fluorescence intensities of intracellular free Ca2+ in cardiomyocytes were significantly increased compared with control group (P < 0.01). By voltage clamp protocol, peak current densities of I(Ca-L) was significantly reduced and I-V curve significantly elevated. Post I/R injury compared with control group (P < 0.01) which could be reversed by Verapamil preconditioning. Verapamil preconditioning also significantly improved diastolic and systolic functions, and reduced the incidence of arrhythmias.

CONCLUSIONS

Myocardial I/R injury might significantly impair heart functions and induce arrhythmias via cellular Ca2+ overload. Verapamil preconditioning could prevent heart I/R injury and reduce arrhythmias by decreasing influx of I(Ca-L), thereby stabilizing cardiomyocytes in myocardial stunning and avoiding occurrence of Ca2+-induced Ca2+ release during I/R injury.

Depressive symptoms and risk factors in Chinese patients with premature ventricular contractions without structural heart disease

HYPOTHESIS

Our objective was to study depressive symptoms and potential risk factors in Chinese persons with premature ventricular contractions (PVCs) without structural heart disease.

METHODS

The Zung self-rating depression scale (ZSDS) was used to assess depressive symptoms. Correlations between depressive symptoms and sociodemographic and medical factors were analyzed by logistic regression.

BACKGROUND

Prevalence of depressive symptoms in coronary heart disease (CHD) is higher that in the general population and those for the majority of other chronic symptoms in patients with premature ventricular contractions (PUCS).

RESULTS

Of 1,144 patients with PVCs (488 males, 656 females), age 51 +/- 23 years, disease duration 1 mo - 23 y, a total of 309 (27%) patients were categorized as having depressive symptoms. Depressive symptoms increased with age, income, education level, nationality, PVC count/24h, society support, and settlement type (p < 0.05). Univariate logistic regression showed that being female, level of education, age, settlement type, and PVC count/24h significantly correlated with depressive symptoms (p < 0.05). Multivariate logistic regression indicated that 5 variables-female sex, education level, settlement type, age, and PVC count/24h significantly and independently related with depressive symptoms (p < 0.05).

CONCLUSIONS

In the Chinese population, depressive symptoms in subjects with PVCs were frequent. The village settlement type, female sex, age, PVC count/24h, and education level were independent risk factors for depressive symptoms. Further research on the relationship between PVCs and depressive symptoms in China is necessary.