Delayed papillary muscle rupture after radiofrequency catheter ablation: A case report.

BACKGROUND: With an increased number of surgical procedures involving the mitral annular region, the risk of mitral valve prolapse (MVP) has also increased. Previous studies have reported that worsening of MVP occurred early after radiofrequency catheter ablation (RFCA) at papillary muscles in ventricular tachycardia (VT) patients with preoperative MVP. CASE SUMMARY: We report a case where MVP and papillary muscle rupture occurred 2 wk after RFCA in a papillary muscle originated VT patient without mitral valve regurgitation or prolapse before. The patient then underwent mitral valve replacement with no premature ventricular contraction or VT. During the surgery, a papillary muscle rupture was identified. Pathological examination showed necrosis of the papillary muscle. The patient recovered after mitral valve replacement. CONCLUSION: Too many ablation procedures and energy should be avoided.

α-adrenoceptor-mediated enhanced inducibility of atrial fibrillation in a canine system inflammation model.

The exact mechanism associated with inflammation and atrial fibrillation (AF) remains unknown. The aim of the present study was to investigate the roles of connexin 43 (Cx43) and a1­adrenergic receptor (α1­AR) activation in the pathogenesis of system inflammation­induced AF. A canine model of chronic low­grade system inflammation was established by administrating a low dose of lipopolysaccharide (LPS; 0.1 µg/kg) for 2 weeks. Programmed stimulation was applied on the right atrial appendage to determine the effective refractory periods (ERP) and the window of vulnerability (WOV). Tumor necrosis factor α (TNF­α) and interleukin 6 (IL­6) levels in plasma and atrial tissue were measured by ELISA. Cx43, Toll­like receptor 4 (TLR4) and nuclear factor κB (NF­κB) proteins were analyzed using western blotting or immunohistochemistry. Administration of LPS for 2 weeks increased the concentration of TNF­α and IL­6 in the plasma and right atrium. ERP was markedly shortened and cumulative WOV was significantly widened in the LPS group. Following treatment with LPS, the amount of Cx43 protein in the area of intercalated disk increased. In addition, a high­density of Cx43 in the lateral connection was identified. LPS also induced the activation of NF­κB in the canine atrium. Administration with the α1­AR blocker doxazosin prevented the production of LPS­induced inflammatory cytokine and reversed the enhanced vulnerability to atrial fibrillation. Doxazosin inhibited the LPS­induced increase in Cx43 protein and heterogeneous distribution, and prevented the activation of NF­κB. These results indicated that chronic low­grade system inflammation may increase the inducibility of AF in a canine model. The underlying mechanism may be involved in the LPS­induced activation of NF­κB, and the increase in Cx43 expression and lateral distribution via an α1-AR-dependent pathway.

Nerve growth factor rescues diabetic mice heart after ischemia/reperfusion injury via up-regulation of the TRPV1 receptor.

AIMS: Nerve growth factor (NGF), a member of the neurotrophin family, plays an essential role in diabetic neuropathy and ischemic heart disease. In the present study, we explored the potential role of NGF and the involvement of TRPV1 receptor in isolated diabetic mouse hearts following ischemia/reperfusion (I/R) injury. METHODS: Adenovirus-mediated NGF gene delivery was performed on diabetic and sham hearts 8weeks after streptozotocin treatment. The sciatic nerve conduction velocity was recorded using a biological signal acquisition system. Forty-eight hours after heart surgery, mice were subjected to I/R injury using a Langendorff system. Several cardiac parameters and the expression of associated molecules were analyzed during the experiment. RESULTS: The sciatic nerve conduction velocity was reduced in diabetic mice compared with that in control mice. Decreased expression of NGF, TRPV1, and the downstream neurotransmitters CGRP and SP was observed in the diabetic hearts. Adenovirus-mediated NGF overexpression reversed the reduction in TRPV1 and downstream neuropeptides, resulting in improved cardiac recovery post-I/R injury in diabetic hearts. The protective effect of NGF was abolished by CGRP8-37 (a selective CGRP antagonist), while it was preserved by low-dose capsaicin. CONCLUSIONS: The NGF-induced up-regulation of TRPV1 via the increased synthesis and release of endogenous CGRP leads to improved cardiac performance in I/R-injured diabetic heart.

Transient cardiac injury during H7N9 infection.

BACKGROUND: Recent reports have characterized virological and clinical features of the novel reassortant avian-origin influenza A (H7N9) virus. However, cardiovascular involvement during H7N9 infection is still unclear. In this study, we evaluate cardiac injury among H7N9-infected patients. MATERIALS AND METHODS: A total of 40 patients who were laboratory-confirmed with H7N9 infection were retrospectively included and grouped by Acute Physiology and Chronic Health Evaluation II (APACHE II) score into four subgroups I(0-10), II(11-20), III(21-30) and IV(31-71). Cardiovascular complications and markers of cardiac injury including creatinine kinase (CK), CK iso-enzyme (CK-MB), cardiac troponin I (cTNI) and brain natriuretic peptide (BNP) were assessed. Electrocardiogram (ECG) and echocardiography (ECHO) were also performed. RESULTS: Half of patients manifested with cardiovascular complications, with hypotension (47.5%) and heart failure (40.0%) the most prevalent. CK, CK-MB and cTNI showed marked increase with H7N9 virus infection but significantly decreased after H7N9 viral tests turned negative. More than half of patients presented with an abnormal ECG, but most of them are benign changes. ECHO examination showed different degree of impairment of cardiac function. Pulmonary artery systolic pressure was increased in all groups. Cardiac damage was more evident in patients with higher APACHE II score. CONCLUSIONS: H7N9 virus exerts a transient impairment on the cardiovascular system. Patients with a higher APACHE II score are more susceptible to cardiac damage.

Lycopene protects against apoptosis in hypoxia/reoxygenation­induced H9C2 myocardioblast cells through increased autophagy.

Lycopene (Ly), the most common type of antioxidant in the majority of diet types, provides tolerance to ischemia/reperfusion injury. However, the underlying mechanism of the protective effects observed following Ly administration remains poorly investigated. The aim of the current study was to investigate whether Ly prevents damage to hypoxia/reoxygenation (HR)­induced H9C2 myocardioblasts in an autophagy­dependent manner. The levels of autophagic markers were detected using western blotting, the level of apoptosis was detected using western blotting and flow cytometry. The activation of autophagy was impaired via knockdown of the expression of 'microtubule­associated protein 1­light chain 3ß (MAP1LC3B)' and 'Beclin 1'. After 16 h hypoxia, followed by 2 h reoxygenation, the expression levels of the microtubule­associated protein 1A/1B­light chain 3 (LC3) and Βeclin 1 autophagic biomarkers, and cell viability were reduced, whereas the percentage of apoptotic cells, and the expression levels of the Bax/B­cell lymphoma 2 (Bcl­2) and active caspase­3 apoptotic biomarkers were increased. Pre­incubation of the cells with different Ly concentrations reversed the HR­induced inhibition of autophagy and cell viability, and the HR­induced elevation in apoptotic levels. The induction of autophagy was accompanied by reduced apoptosis, and decreased expression levels of Bax/Bcl­2 and active caspase­3. In addition, the impairment of autophagy by silencing the expression of MAP1LC3B and Beclin 1 accelerated HR­induced H9C2 cell apoptosis and the Ly­mediated protective effects disappeared. Furthermore, Bax/Bcl­2 and active caspase­3 expression levels were increased. Moreover, Ly­induced autophagy was associated with increased adenosine monophosphate kinase (AMPK) phosphorylation. Suppressed AMPK phosphorylation using compound C terminates Ly­mediated cytoprotective effects. Ly treatment improves cell viability and reduces apoptosis as a result of the activation of the adaptive autophagic response on HR­induced H9C2 myocardioblasts. AMPK phosphorylation may be involved in the progression.

Autophagy protects against senescence and apoptosis via the RAS-mitochondria in high-glucose-induced endothelial cells.

BACKGROUNDS: Autophagy is an important process in the pathogenesis of diabetes and plays a critical role in maintaining cellular homeostasis. However, the autophagic response and its mechanism in diabetic vascular endothelium remain unclear. METHODS AND RESULTS: We studied high-glucose-induced renin-angiotensin system (RAS)-mitochondrial damage and its effect on endothelial cells. With regard to therapeutics, we investigated the beneficial effect of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs) against high-glucose-induced endothelial responses. High glucose activated RAS, enhanced mitochondrial damage and increased senescence, apoptosis and autophagic-responses in endothelial cells, and these effects were mimicked by using angiotensin II (Ang). The use of an ACEI or ARB, however, inhibited the negative effects of high glucose. Direct mitochondrial injury caused by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) resulted in similar negative effects of high glucose or Ang and abrogated the protective effects of an ACEI or ARB. Additionally, by impairing autophagy, high-glucose-induced senescence and apoptosis were accelerated and the ACEI- or ARB-mediated beneficial effects were abolished. Furthermore, increases in FragEL™ DNA Fragmentation (TUNEL)-positive cells, ß-galactosidase activation and the expression of autophagic biomarkers were revealed in diabetic patients and rats, and the treatment with an ACEI or ARB decreased these responses. CONCLUSIONS: These data suggest that autophagy protects against senescence and apoptosis via RAS-mitochondria in high-glucose-induced endothelial cells.

Advances of research on glycinin and ß-conglycinin: a review of two major soybean allergenic proteins.

Being an important crop, soybean is widely used in the world and plays a vital role in human and animal nutrition. However, it contains several antinutritional factors (ANFs) including soybean agglutinin, soybean protease inhibitors, soybean allergenic proteins, etc., that may result in poor food utilization, decreased growth performance, and even disease. Among these ANFs, soybean allergenic proteins can lead to allergic reactions in human and animals, which has become a public problem all over the world, but our knowledge on it is still inadequate. This paper aims to provide an update on the characteristics, detection or exploration methods, and in vivo research models of soybean allergenic proteins; especially glycinin and ß-conglycinin are deeply discussed. Through this review, we may have a better understanding on the advances of research on these two soybean allergenic proteins. Besides, the ingredient processing used to reduce the allergenicity of soybean is also reviewed.

The effects of dietary fatty acids on liver fatty acid composition and Delta(6)-desaturase expression differ with ambient salinities in Siganus canaliculatus.

Delta(6)-Desaturase (linoleoyl-CoA desaturase, EC 1.14.19.3) is the rate-limiting enzyme in the biosynthetic pathway of highly unsaturated fatty acid (HUFA). In this report, a Delta6 desaturase-like cDNA was cloned, and the relation of HUFA biosynthetic activity in liver with ambient salinity as well as dietary fatty acids was investigated in the euryhaline teleost Siganus canaliculatus. After the juveniles were fed four formulated diets (D1-D4) with different essential fatty acid composition (D1 with 23.49% HUFA, D2-D4 were HUFA-free, linoleic and alpha-linolenic acids account for 21.1% and 0.38%, 13.99% and 11.64%, 18.31% and 5.82% of the total fatty acids, respectively) for nine weeks, the growth performance showed no difference among groups in brackish water (10 ppt) or seawater (32 ppt) (P>0.05). Comparing liver fatty acids with fish fed D1, the content of arachidonic acid in fish fed D2 or D4 was significantly higher in 10 ppt (P<0.05), but showed no difference in 32 ppt; the contents of eicosapentaenoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) acids in 10 ppt, as well as EPA in 32 ppt in fish fed D3 showed no difference, whereas those of DPA and DHA were significantly lower in 32 ppt (P<0.05). These data suggest that S. canaliculatus may convert linoleic and alpha-linolenic acids into HUFA and such a capacity was stronger in low salinity than that in high salinity. Consistent with this, the liver levels of Delta6 desaturase mRNA in fish fed D2-D4 were generally higher than in fish fed D1 in both salinities, and the total expression level in 10 ppt was about 1.56 times of that in 32 ppt, suggesting that transcriptional control of Delta6 desaturase is involved in such a HUFA biosynthesis. To our knowledge, this is the first report showing the relation of HUFA biosynthetic activity with ambient salinity in a euryhaline fish.