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Congenital bilateral absence of the vas deferens (CBAVD) is observed in 1%-2% of males presenting with infertility and is clearly associated with cystic fibrosis transmembrane conductance regulator (CFTR) mutations. CFTR is one of the most well-known genes related to male fertility. The frequency of CFTR mutations or impaired CFTR expression is increased in men with nonobstructive azoospermia (NOA). CFTR mutations are highly polymorphic and have established ethnic specificity. Compared with F508Del in Caucasians, the p.G970D mutation is reported to be the most frequent CFTR mutation in Chinese patients with cystic fibrosis. However, whether p.G970D participates in male infertility remains unknown. Herein, a loss-of-function CFTR p.G970D missense mutation was identified in a patient with CBAVD and NOA. Subsequent retrospective analysis of 122 Chinese patients with CBAVD showed that the mutation is a common pathogenic mutation (4.1%, 5/122), excluding polymorphic sites. Furthermore, we generated model cell lines derived from mouse testes harboring the homozygous Cftr p.G965D mutation equivalent to the CFTR variant in patients. The Cftr p.G965D mutation may be lethal in spermatogonial stem cells and spermatogonia and affect the proliferation of spermatocytes and Sertoli cells. In spermatocyte GC-2(spd)ts (GC2) Cftr p.G965D cells, RNA splicing variants were detected and CFTR expression decreased, which may contribute to the phenotypes associated with impaired spermatogenesis. Thus, this study indicated that the CFTR p.G970D missense mutation might be a pathogenic mutation for CBAVD in Chinese males and associated with impaired spermatogenesis by affecting the proliferation of germ cells.

Background End-stage heart failure is a major risk of mortality. The conductive super-aligned carbon nanotubes sheets (SA-CNTs) has been applied to restore the structure and function of injured myocardium through tissue engineering, and developed as efficient cardiac pacing electrodes. However, the interfacial interaction between SA-CNTs and the surface cells is unclear, and it remains challenge to restore the diminished contraction for a seriously damaged heart. Results A concept of a multifunctional power assist system (MPS) capable of multipoint pacing and contraction assisting is proposed. This device is designed to work with the host heart and does not contact blood, thus avoiding long-term anticoagulation required in current therapies. Pacing electrode constructed by SA-­CNTs promotes the epithelial-mesenchymal transition and directs the migration of pro-regenerative epicardial cells. Meanwhile, the power assist unit reveals an excellent frequency response to alternating voltage, with natural heart mimicked systolic/diastolic amplitudes. Moreover, this system exhibits an excellent pacing when attached to the surface of a rabbit heart, and presents nice biocompatibility in both in vitro and in vivo evaluation. Conclusions This MPS provides a promising non-blood contact strategy to restore in situ the normal blood-pumping function of a failed heart.

Curettage of benign bone tumor is a common cause for bone defect. For such bone defect repair, autogenous bone, allogeneic bone and traditional artificial bone graft substitutes have many disadvantages. In recent years, a biomimetic mineralized collagen (MC) with similar composition and microstructures to the natural bone matrix was developed and used for treating various bone defects. In this work, a retrospective study analyzed clinical outcomes of patients treated with curettage of benign bone tumors and bone grafting with MC, in comparison to another group treated with the same surgical method and autogenous bone. Lane–Sandhu X-ray score of the autogenous bone group was superior to the MC group at 1 month after the operation, but the two groups had no statistical difference at 6 and 12 months. The MC group was better in Musculoskeletal Tumor Society scoring at 1 and 6 months after the operation, and the two groups had no statistical difference at 12 month. Therefore, the MC performed not as good as autogenous bone in early stage of bone healing but achieved comparable outcomes in long-term follow-ups. Moreover, the MC has advantages in function recovery and avoided potential complications induced by harvesting autogenous bone.

Background Catheter-based renal denervation (RDN) has achieved promising outcomes to treat hypertension in recent randomized controlled trials. Objectives The purpose of this study was to assess the feasibility, efficacy, and safety of noninvasive stereotactic body radiotherapy (SBRT) as an approach for RDN. Methods SBRT was performed in 24 renal arteries from 12 normotensive swine at doses of 25, 35, and 45 Gy (n = 4 each), and an additional 4 swine served as controls. Blood pressure (BP), renal function, and serum norepinephrine (NE) values were obtained at baseline and at 7 days, 1 month, and 3 months after SBRT. Abdominal contrast-enhanced computed tomography (CT) was performed after 3 months before euthanasia. Renal NE concentration was determined, and histological analysis and immunohistochemistry against tyrosine hydroxylase were performed. Results SBRT procedure was successful in all 12 swine. BP was comparable among groups. Serum and renal NE levels at 3 months were significantly lower in treatment groups compared with control group. Furthermore, SBRT resulted in significantly greater nerve injury score and lower tyrosine hydroxylase score compared with control subjects, whereas there were no statistical differences between SBRT groups. Circumferential lesions created with 35 and 45 Gy were significantly greater than with 25 Gy. CT and histology analysis revealed that animals receiving 35 and 45 Gy experienced more collateral damage, which was minimal in the 25-Gy group. Conclusions Noninvasive SBRT was feasible and effective for complete, circumferential RDN in a swine model, with dosage at 25 Gy providing the safest short-term profile.

Aims. Myocardial ischemia/reperfusion (I/R) injury is a leading cause of cardiomyocyte loss and subsequent ventricular dysfunction after restoring the coronary blood flow and contributes to considerable increase in morbidity and mortality. Resveratrol has been declared to confer cardioprotection against in vivo and ex vivo myocardial I/R injury. Here, we have sought to investigate the effects of preconditioning with resveratrol on myocardial I/R damage across the small animal studies. Methods and Results. The MEDLINE, Google Scholar, PubMed, and Cochrane databases were searched for preclinical studies investigating resveratrol vs. vehicle published from the inception to July 2018. Eventually, 10 in vivo and 7 ex vivo studies with 261 animals (130 for resveratrol; 131 for vehicle) were included for meta-analysis. Pooled estimates for primary outcomes demonstrated that pretreatment with resveratrol significantly reduced the infarct size after myocardial I/R injury irrespective of in vivo (weighted mean difference (WMD): -13.42, 95% CI: -16.63 to -10.21, P≤0.001) or ex vivo (WMD: -15.05, 95% CI: -18.23 to -11.86, P≤0.001) studies. Consistently, stratified analysis according to the reperfusion duration, route of administration, or timing regimen of pretreatment all showed the infarct-sparing benefit of resveratrol. Metaregression did not indicate any difference in infarct size based on species, sample size, state, route of administration, reperfusion duration, and timing regimen of pretreatment. Meanwhile, sensitivity analysis also identified the cardioprotection of resveratrol with robust results in spite of significant heterogeneity. Conclusions. Preconditioning with resveratrol appears to prevent the heart from I/R injury in comparison with vehicle, as evidenced by limited infarct size in a preclinical setting. Studies with large animals or randomized controlled trials will add more evidence and provide the rationale for clinical use.

Background and purpose 9-Phenanthrol, known as a specific inhibitor of the transient receptor potential melastatin 4 (TRMP4) channel, has been shown to modulate cardiac electrical activity and exert antiarrhythmic effects. However, its pharmacological effects remain to be fully explored. Here, we tested the hypothesis that cardiac sodium current inhibition contributes to the cardioprotective effect of 9-phenanthrol. Experimental approach Single ventricular myocytes (VMs) and Purkinje cells (PCs) were enzymatically isolated from rabbits. Arterially perfused rabbit wedge preparations were also used, and transmural electrocardiogram and endocardial action potentials (APs) were simultaneously recorded. Wild-type and mutated human recombinant SCN5A were expressed in HEK293 cells. Anemonia toxin II (ATX-II) was used to amplify the late sodium current (INaL ) and induce arrhythmias. Whole-cell patch clamp technique was used to record APs and ionic currents. Key results 9-Phenanthrol (10-50 μM) stabilized ventricular repolarization and abolished arrhythmias induced by ATX-II in both isolated VMs, PCs and wedge preparations. Further study revealed that 9-phenanthrol modulated the gating properties of cardiac sodium channels and dose-dependently inhibited INaL and peak sodium current (INaP ) in VMs with an IC50 of 18 and 71.5 μM respectively. Its ability to inhibit INaL was further confirmed in PCs and HEK293 cells expressing SCN5A mutations. Conclusions and implications Our results indicate that 9-phenanthrol modulates the gating properties of cardiac sodium channels and inhibits INaL and INaP , which may contribute to its antiarrhythmic and cardioprotective effects.

Rate-dependent repolarization (RDR) of action potential (AP) in cardiomyocyte plays a critical role in the genesis of arrhythmias and RDR in atrium has been linked with atrial fibrillation. However, detailed studies focusing on the role of RDR in rabbit atrium are scant. In this study, atrial cells were isolated from rabbit heart and rate-dependent property was explored in single atrial cell to elucidate the underlying mechanism. Our results indicated that rate-dependent prolongation was evident at the action potential duration at 20% (APD20) and 50% (APD50) repolarization but not at 90% repolarization (APD90) under control condition. Using transient outward potassium current (Ito) inhibitor 4-Aminopyridine (4-AP, 2 mM) effectively eliminated the changes in APD20 and APD50, and unmasked the rate-dependent reduction of APD90 which could be diminished by further adding L-type calcium current (ICaL) inhibitor nifedipine (30 μM). However, using the selective late sodium current (INaL) inhibitor GS-458967 (GS967, 1 μM) caused minimal effect on APD90 of atrial cells both in the absence and presence of 4-AP. In consistence with results from APs, Ito and ICaL displayed significant rate-dependent reduction because of their slow reactivation kinetics. In addition, the magnitude of INaL in rabbit atrium was so small that its rate-dependent changes were negligible. In conclusion, our study demonstrated that Ito and ICaL mediate RDR of AP in rabbit atrium, while minimal effect of INaL was seen.

Introduction CF-sensing catheter emerged as a novel ablation technology and was increasingly used in clinical practice. Nonetheless, available evidence of efficacy and safety comparison between CF-guided RF catheter ablation and non-CF-guided ablation for treatment of AF was still lacking. Methods and results Twenty-two eligible studies were included after systematic review through the MEDLINE, Google Scholar, the Cochrane Library and PubMed databases. AF/atrial tachycardia-free survival was markedly improved in CF-guided catheter ablation compared with non-CF-guided ablation at a median 12-month follow-up (RR: 1.12, 95% CI: 1.06 to 1.19, p = 0.000, fixed). Notably, CF-guided catheter ablation presented a robust survival benefit for treatment of paroxysmal AF (RR: 1.10, 95% CI: 1.03 to 1.18, p = 0.005, fixed), but not persistent AF (RR: 1.07, 95% CI: 0.89 to 1.28, p = 0.466, fixed). Moreover, procedure time (WMD: -23.87, 95% CI: -33.83 to -13.91, p = 0.000, random), fluoroscopy time (WMD: -7.78, 95% CI: -13.93 to -1.63, p = 0.013, random) and RF time (WMD: -3.98, 95% CI: -7.78 to -0.17, p = 0.040, random) were significantly reduced in CF-guided catheter ablation. The incidence of procedure-related complications did not differ between these two technologies (RR: 0.83, 95% CI: 0.59 to 1.16, p = 0.271, fixed). Conclusion CF-guided RF catheter ablation was associated with a significant AF/atrial tachycardia-free survival benefit compared with non-CF-guided ablation in patients with paroxysmal AF rather than persistent AF. In addition, CF-guided ablation strategy also reduced the procedure time, fluoroscopy time, as well as RF time despite no distinct effect on the alleviation of procedure-related complications. This article is protected by copyright. All rights reserved

Cardiac hypertrophy is characterized by increased myofibrillogenesis. Angiotensin II (Ang-II) is an essential mediator of the pressure overload–induced cardiac hypertrophy in part through RhoA/ROCK (small GTPase/Rho-associated coiled-coil containing protein kinase) pathway. FHOD3 (formin homology 2 domain containing 3), a cardiac-restricted member of diaphanous-related formins, is crucial in regulating myofibrillogenesis in cardiomyocytes. FHOD3 maintains inactive through autoinhibition by an intramolecular interaction between its C- and N-terminal domains. Phosphorylation of the 3 highly conserved residues (1406S, 1412S, and 1416T) within the C terminus (CT) of FHOD3 by ROCK1 is sufficient for its activation. However, it is unclear whether ROCK-mediated FHOD3 activation plays a role in the pathogenesis of Ang-II–induced cardiac hypertrophy. In this study, we detected increases in FHOD3 expression and phosphorylation in cardiomyocytes from Ang-II–induced rat cardiac hypertrophy models. Valsartan attenuated such increases. In cultured neonate rat cardiomyocytes, overexpression of phosphor-mimetic mutant FHOD3-DDD, but not wild-type FHOD3, resulted in myofibrillogenesis and cardiomyocyte hypertrophy. Expression of a phosphor-resistant mutant FHOD3-AAA completely abolished myofibrillogenesis and attenuated Ang-II–induced cardiomyocyte hypertrophy. Pretreatment of neonate rat cardiomyocytes with ROCK inhibitor Y27632 reduced Ang-II–induced FHOD3 activation and upregulation, suggesting the involvement of ROCK activities. Silencing of ROCK2, but not ROCK1, in neonate rat cardiomyocytes, significantly lessened Ang-II–induced cardiomyocyte hypertrophy. ROCK2 can directly phosphorylate FHOD3 at both 1412S and 1416T in vitro and is more potent than ROCK1. Both kinases failed to phosphorylate 1406S. Coexpression of FHOD3 with constitutively active ROCK2 induced more stress fiber formation than that with constitutively active ROCK1. Collectively, our results demonstrated the importance of ROCK2 regulated FHOD3 expression and activation in Ang-II–induced myofibrillogenesis, thus provided a novel mechanism for the pathogenesis of Ang-II–induced cardiac hypertrophy.

Cardiac fibrosis (CF), a repairing process following myocardial infarction (MI), is characterized by abnormal proliferation of cardiac fibroblasts and excessive deposition of extracellular matrix (ECM) resulting in inevitable resultant heart failure. TGF-β (transforming growth factor-β)/ALK5 (Activin receptor-like kinase 5)/Smad2/3/4 pathways have been reported to be involved in the process. Recent studies have implicated both activin and its specific downstream component ALK4 in stimulating fibrosis in non-cardiac organs. We recently reported that ALK4 is upregulated in the pressure-overloaded heart and its partial inhibition attenuated the pressure overload-induced CF and cardiac dysfunction. However, the role of ALK4 in the pathogenesis of MI-induced CF, which is usually more severe than that induced by pressure-overload, remains unknown. Here we report: 1) In a wild-type mouse model of MI, ALK4 upregulation was restricted in the fibroblasts of the infarct border zone; 2) In contrast, ALK4+/- mice with a haplodeficiency of ALK4 gene, showed a significantly attenuated CF in the border zone, with a smaller scar size, a preserved cardiac function and an improved survival rate post-MI; 3) Similarly to pressure-overloaded heart, these beneficial effects might be through a partial inactivation of the Smad3/4 pathway but not MAPK cascades; 4) The apoptotic rate of the cardiomyocytes were indistinguishable in the border zone of the wild-type control and ALK4+/- mice; 5) Cardiac fibroblasts isolated from ALK4+/- mice showed reduced migration, proliferation and ECM synthesis in response to hypoxia. These results indicate that partial inhibition of ALK4 may reduce MI-induced CF, suggesting ALK4 as a novel target for inhibition of unfavorable CF and for preservation of LV systolic function induced by not only pressure-overload but also MI.

Silibinin is a traditional medicine and utilized for liver protection with antioxidant, anti-inflammation and anti-apoptosis properties. However, its role in myocardial I/R injury and the mechanism involved is currently unknown. In the present study, Silibinin treatment improves cardiac function and limits infarct size, and subsequently inhibits fibrotic remodeling in mice with myocardial I/R injury. Mechanistically, silibinin reduces cardiomyocytes apoptosis, attenuates mitochondrial impairment and endoplasmic reticulum (ER) stress, alleviates ROS generation, neutrophil infiltration and cytokines release. Consistently, silibinin prevents H9C2 cells from hypoxia/reperfusion-induced cell death, oxidative stress and inflammation in vitro. Furthermore, H9C2 cells treated with silibinin blocks NF-κB signaling activation by inhibiting IKKα phosphorylation, IκBα degradation and p65 NF-κB nuclear translocation during hypoxia/ reperfusion. In addition, silibinin plus BAY 11-7082 (a selected NF-κB inhibitor) do not provide incremental benefits in improving myocytes apoptosis, oxidative stress and inflammation in comparison with NF-κB signaling inhibition only. Thus, silibinin-mediated cardioprotection in myocardial I/R injury is associated with decreased apoptosis, oxidative stress and inflammatory response through deactivation of NF-κB pathway.

Background Activin receptor-like kinase 4 (ALK4), a downstream receptor of transforming growth factor-β superfamily, is highly expressed in the mammal heart. Upregulated ALK4 expression and activated ALK4-small mother against decapentaplegic (Smad)2/3 signaling have been reported to play a pivotal role in tumorigenesis and in the development of systemic sclerosis. However, the role of ALK4-Smad2/3 pathway in the pathogenesis of cardiac hypertrophy and cardiac fibrosis remains unknown. Methods and results In this study, the mice with heterozygous knocking out of ALK4 gene (ALK4) were generated and subjected to aortic banding for 4 weeks. We found that ALK4 expression was upregulated in aortic banding-induced model of cardiac hypertrophy and cardiac fibrosis in wild-type mice. Compared with the wild-type mice, ALK4mice demonstrated a similar extent of aortic banding-induced cardiac hypertrophy, but a significant suppression of cardiac fibrosis to 64.8% of the basal level, and a subsequent amelioration in the cardiac dysfunction (left ventricle ejection fraction: 59.0 ± 6.4 in wild-type mice vs. 75.6 ± 3.9% in ALK4 mice; left ventricle end-diastolic pressure: 16.6 ± 4.7 mmHg in wild-type mice vs. 6.6 ± 2.8 mmHg in ALK4 mice) associated with inhibition of cardiac fibroblast activation and cardiomyocyte apoptosis. In vitro, ALK4 haploinsufficiency blocked the cellular proliferation/differentiation and collagen production in cultured cardiac fibroblasts after angiotensin-II stimulation. Mechanistically, ALK4 haploinsufficiency resulted in the suppression of Smad2/3 activity. Conclusion Our results demonstrate that ALK4 haploinsufficiency ameliorates cardiac fibrosis and dysfunction in a mouse pressure-overload model associated with inhibition of cardiac fibroblast activation and cardiomyocyte apoptosis through the suppression of Smad2/3 activity, and suggest that ALK4 is a novel therapeutic target in treating pressure overload-induced cardiac remodeling and heart failure.

Sperm cryopreservation has been widely used in assisted reproduction, but conventional techniques are not suitable for the cryopreservation of small numbers of sperm. The application of the single sperm cryopreservation technique has significantly improved the clinical treatment of cryptozoospermia and non-obstructive azoospermia. Ever since Cohen et al first developed the method of single sperm cryopreservation in 1997, constant efforts have been made to develop the carriers for this technique. In this review, we mainly discuss the existing methods and clinical outcomes of single sperm cryopreservation.精子冷冻技术在辅助生殖支柱(ART)中已得到广泛应用，但常规冷冻方法不适用于冷冻微量精子，单精子冷冻技术的应用将在很大程度上改善隐匿性精子症、非梗阻性无精症患者的临床治疗。从1997年Cohen等最先提出单精子冷冻概念至今，研究者们不断地尝试探索单精子冷冻载体，本文依据载体的分类，对单精子冷冻方法及临床结局做一简要阐述。.

Background Activin receptor‐like kinase 4 ( ALK 4) is highly expressed in mammal heart. Atrial fibrillation ( AF ) is closely related to ventricular pressure overload. Because pressure overload increases atrial pressure and leads to atrial remodeling, it would be informative to know whether ALK 4 exerts potential effects on atrial remodeling and AF vulnerability in a pressure‐overload model. Methods and Results Wild‐type littermates and ALK 4 +/− mice were subjected to abdominal aortic constriction or a sham operation. After 4 or 8 weeks, echocardiographic and hemodynamic measurements were performed, and inducibility of AF was tested. The hearts were divided into atria and ventricles and then were fixed in formalin for staining, or they were weighted and snap‐frozen for quantitative real‐time polymerase chain reaction and Western blot analysis. Compared with wild‐type littermates, ALK 4 +/− mice demonstrated a similar extent of atrial hypertrophy but significantly suppressed atrial fibrosis at 8 weeks post–abdominal aortic constriction. ALK 4 haplodeficiency partially blocked abdominal aortic constriction–induced upregulation of monocyte chemotactic protein 1 and interleukin‐6, and the increased chemotaxin of macrophages. ALK 4 haplodeficiency also blunted a reduction of connexin 40 and redistribution of connexin 43 from the intercalated disk to the lateral membranes, thereby improving localized conduction abnormalities. Meanwhile, ALK 4 haplodeficiency inhibited abdominal aortic constriction–induced decreased I N a , I C a‐L and I K 1 densities as well as the accompanying action potential duration shortening. Mechanistically, ALK 4 haploinsufficiency resulted in the suppression of Smad2/3 activity in this model. Conclusions Our results demonstrate that ALK 4 haplodeficiency ameliorates atrial remodeling and vulnerability to AF in a pressure‐overload model through inactivation of the Smad2/3 pathway, suggesting that ALK 4 might be a potential therapeutic target in combating pressure overload–induced AF .

Background The efficacy and safety of adjuvant substrate modification (SM; either linear ablation [LA] or complex fractionated atrial electrogram [CFAE] ablation) in addition to pulmonary vein isolation (PVI) for the treatment of symptomatic, drug-refractory atrial fibrillation (AF), have still not been clarified and need further assessment. Method We systematically searched the PubMed, MEDLINE, and Cochrane databases for studies comparing PVI with adjunctive SM versus PVI alone for treatment of drug-refractory AF. Results Twenty-six (26) studies including 3,409 patients (1,975 PVI + SM; 1,434 PVI alone) were included for further analysis. Atrial fibrillation/atrial tachycardia-free survival of patients with PVI + SM was comparable with that of PVI alone (relative risk [RR], 1.06; 95% confidence interval [CI], 0.98-1.14; p = 0.143). In line with this, the primary clinical outcomes were robust, irrespective of additional LA (RR, 1.07; 95% CI, 0.97-1.18; p = 0.194) or CFAE ablation (RR, 1.04; 95% CI, 0.93-1.16; p = 0.534). Adjuvant SM is associated with longer procedural time (weighted mean difference, 20.72; 95% CI, 10.25-31.20; p = 0.0) and fluoroscopy time (weighted mean difference, 6.66; 95% CI, 1.74-11.58; p = 0.000); surprisingly, it presented similar procedure-related complications as PVI alone during AF catheter ablation (RR, 1.01; 95% CI, 0.68-1.50; p = 0.946). Conclusions Adjuvant LA or CFAE ablation do not provide incremental benefit over PVI alone. Although substrate-based ablation markedly prolonged procedural and fluoroscopic duration, there was no evidence of increased risk of procedure-related complications.

Patients with high-risk long QT syndrome (LQTS) mutations may experience life-threatening cardiac events. The present study sought to characterize a novel pathogenic mutation, KCNQ1p.Thr312del, in a Chinese LQT1 family. Clinical and genetic analyses were performed to identify this novel causative gene mutation in this LQTS family. Autosomal dominant inheritance of KCNQ1p.T312del was demonstrated in the three-generation pedigree. All mutation carriers presented with prolonged QT intervals and experienced recurrent syncope during exercise or emotional stress. The functional consequences of the mutant channel were investigated by computer homology modeling as well as whole-cell patch-clamp, western-blot and co-immunoprecipitation techniques using transfected mammalian cells. T312 is in the selectivity filter (SF) of the pore region of the KCNQ1-encoded channel. Homology modeling suggested that secondary structure was altered in the mutant SF compared with the wild-type (WT) SF. There were no significant differences in Kv7.1 expression, membrane trafficking or physical interactions with KCNE1-encoded subunits between the WT and mutant transfected channels. However, the KCNQ1p.T312del channels expressed in transfected cells were non-functional in the absence or presence of auxiliary KCNE1-subunits. Dominant-negative suppression of current density and decelerated activation kinetics were observed in cells expressing KCNQ1WT and KCNQ1p.T312del combined with KCNE1 (KCNQ1WT/p.T312del + KCNE1 channels). Those electrophysiological characteristics underlie the pathogenesis of this novel mutation and also suggest a high risk of cardiac events in patients carrying KCNQ1p.T312del. Although protein kinase A-dependent current increase was preserved, a significant suppression of rate-dependent current facilitation was noted in the KCNQ1WT/p.T312del + KCNE1 channels compared to the WT channels during 1- and 2-Hz stimulation, which was consistent with the patients’ phenotype being triggered by exercise. Overall, KCNQ1p.Thr312del induces a loss of function in channel electrophysiology, and it is a high-risk mutation responsible for LQT1.

BACKGROUND AND PURPOSE: 9‐Phenanthrol, known as a specific inhibitor of the transient receptor potential melastatin 4 (TRMP4) channel, has been shown to modulate cardiac electrical activity and exert antiarrhythmic effects. However, its pharmacological effects remain to be fully explored. Here, we tested the hypothesis that cardiac sodium current inhibition contributes to the cardioprotective effect of 9‐phenanthrol. EXPERIMENTAL APPROACH: Single ventricular myocytes (VMs) and Purkinje cells (PCs) were enzymatically isolated from rabbits. Arterially perfused rabbit wedge preparations were also used, and transmural electrocardiogram and endocardial action potentials (APs) were simultaneously recorded. Wild‐type and mutated human recombinant SCN5A were expressed in HEK293 cells. Anemonia toxin II (ATX‐II) was used to amplify the late sodium current (I(NaL)) and induce arrhythmias. Whole‐cell patch clamp technique was used to record APs and ionic currents. KEY RESULTS: 9‐Phenanthrol (10–50 μM) stabilized ventricular repolarization and abolished arrhythmias induced by ATX‐II in both isolated VMs, PCs and wedge preparations. Further study revealed that 9‐phenanthrol modulated the gating properties of cardiac sodium channels and dose‐dependently inhibited I(NaL) and peak sodium current (I(NaP)) in VMs with an IC(50) of 18 and 71.5 μM respectively. Its ability to inhibit I(NaL) was further confirmed in PCs and HEK293 cells expressing SCN5A mutations. CONCLUSIONS AND IMPLICATIONS: Our results indicate that 9‐phenanthrol modulates the gating properties of cardiac sodium channels and inhibits I(NaL) and I(NaP), which may contribute to its antiarrhythmic and cardioprotective effects.

Clinical Observations on Repair of Non-Infected Bone Nonunion by Using Mineralized Collagen Graft Jian-Ming Kou1 ∗, Ting-You Fu2, Xue-Jun Jia1, Jian-Wen Hou1, Chong Gao1, Yuan-Zheng Ma3, Zhi-Ye Qiu4, and Fu-Zhai Cui4 1Department of Orthopedics, The Second People’s Hospital of Lianyungang, Lianyungang 222000, China 2Department of Orthopedic Surgery, The 401th Hospital of Chinese People’s Liberation Army, Qingdao 266100, China 3Department of Orthopedics, The 309th Hospital of Chinese People’s Liberation Army, Beijing 100091, China 4Institute for Regenerative Medicine and Biomimetic Materials, Tsinghua University, Beijing 100084, China

Rate-dependent repolarization (RDR) of action potential (AP) in cardiomyocyte plays a critical role in the genesis of arrhythmias and RDR in atrium has been linked with atrial fibrillation. However, detailed studies focusing on the role of RDR in rabbit atrium are scant. In this study, atrial cells were isolated from rabbit heart and rate-dependent property was explored in single atrial cell to elucidate the underlying mechanism. Our results indicated that rate-dependent prolongation was evident at the action potential duration at 20% (APD20) and 50% (APD50) repolarization but not at 90% repolarization (APD90) under control condition. Using transient outward potassium current (I

Aims Cryoablation is a promising alternative technique to RF ablation for treating paroxysmal AF with encouraging results. However, data about the efficacy and safety comparison between cryoablation and RF ablation is still lacking. Methods and results We systematically search the PubMed, the Cochrane Library, MEDLINE and Google Scholar databases, and finally identify 16 eligible studies including 7195 patients (2863 for cryoablation; 4332 for RF ablation). Freedom from AF/atrial tachycardial replase is slightly higher in cryoablation than RF ablation during a median 12 months of follow-up, with no statistical significant (RR: 1.05, 95% CI: 0.98–1.13, P = 0.159). In cryoablation, the procedure time is substantially shortened (WMD: −27.66, 95% CI: −45.24 to − 10.08, P = 0.002), whereas the fluoroscopy time is identical to RF ablation (WMD: −0.37, 95% CI: −2.78 to 2.04, P = 0.763). Procedure-related adverse events in cryoablation are parallel with that in RF ablation (RR: 1.08, 95% CI: 0.86–1.35, P = 0.159). Conclusions Compared with RF ablation, cryoablation present a comparable long-term AF/atrial tachycardial-free survival and procedure-related adverse events. Meanwhile, cryoablation markedly shorten the procedure time, nonetheless, with negligible impact on the fluoroscopy time.

Aims Adenosine had been reported to unmask dormant conduction and thus identify pulmonary vein at risk of reconnection. However, the role of adjunctive adenosine infusion after pulmonary vein isolation (PVI) on long-term arrhythmia-free survival was still contentious. The purpose of the present meta-analysis was to assess the association of adenosine testing with long-term ablation success in patients with atrial fibrillation (AF) (i.e. freedom from AF recurrence). Methods and results We systematically searched the electronic databases and finally included 10 studies, with 1771 patients undergoing adenosine-guided PVI and 1787 patients undergoing conventional PVI. In comparison to conventional PVI alone, adenosine-guided PVI improved the arrhythmia-free survival by 17% during a median follow-up of 12 months [relative risk (RR): 1.17; 95% confidence interval (CI): 1.07 to 1.27; P = 0.014]. Patients undergoing adenosine-guided PVI had similar fluoroscopy time to those who undergoing conventional PVI [weighted mean difference (WMD): 1.76; 95% CI: −5.66 to 9.17; P = 0.64], despite longer procedure time (WMD: 20.6; 95% CI: 0.70 to 40.50; P = 0.042). Conclusion From the available data of clinical studies, adenosine-guided PVI was associated with an increased arrhythmia-free survival when compared with conventional PVI in patients undergoing catheter ablation for AF.

Background Purkinje cells (PCs) have a steeper rate dependence of repolarization and are more susceptible to arrhythmic activity than do ventricular myocytes (VMs). Late sodium current (I NaL ) is rate dependent and contributes to rate dependence of repolarization. Objective This study sought to test our hypothesis that PCs have a larger rate dependence of I NaL , contributing to their steeper rate dependence of repolarization and higher susceptibility to arrhythmic activity, than do VMs. Methods I NaL was recorded in isolated rabbit PCs and VMs with the whole-cell patch clamp technique. Action potential was examined using the microelectrode technique. Results Compared with VMs, PCs exhibited a significantly larger rate dependence of I NaL with a larger I NaL to basic cycle length (BCL) slope. Moreover, PCs had a larger rate dependence of I NaL decay and slower recovery kinetics. Interestingly, the larger rate dependence of I NaL matched to a steeper rate dependence of action potential duration (APD) in PCs. The I NaL blocker tetrodotoxin significantly blunted, while the I NaL enhancer anemone toxin (ATX-II) significantly increased, the rate dependence of I NaL and APD in PCs and VMs. In the presence of ATX-II, the rate dependence of I NaL in PCs was markedly larger than that in VMs, causing a much steeper rate dependence of APD in PCs. Accordingly, PCs exhibited greater rate-dependent electrical instability and were more prone to ATX-II–induced early afterdepolarizations, which were completely inhibited by the I NaL inhibitor ranolazine. Conclusion PCs have a significantly larger rate dependence of I NaL than do VMs because of distinctive I NaL decay and recovery kinetics, which contributes to their larger rate adaptation, and simultaneously predisposes them to a higher risk of arrhythmogenesis.

Activin receptor-like kinase 4 (ALK4), a downstream receptor of transforming growth factor-β superfamily, is highly expressed in the mammal heart. We recently reported that ALK4 is upregulated in pressure-overloaded heart and ALK4 haplodeficiency attenuated the pressure overload-induced cardiac

In this paper, the function and composition as well as the key techniques (ultra-long distance communication, attitude determination and control, thermal control, ultra-low temperature acclimatization, etc.) of China's first Mars probe are analyzed. In combination with practical engineering conditions, the solutions of these key techniques are given. The design features of the probe are summarized, as a reference for developing the probes of the subsequent related missions in China.

Dual-specificity phosphatase 14 (Dusp14), an important negative modulator of mitogen-activated protein kinase (MAPK) signaling pathways, has been implicated in inflammatory immune response, cancers, cell differentiation and proliferation. The role of Dusp14 in chronic pressure overload-induced cardiac hypertrophy has not been explored. Here we have shown that Dusp14-/- knockout mice and cardiac-specific Dusp14 transgenic mice were generated and subjected to aortic banding (AB) for 4 weeks. Our results demonstrated that genetic loss of Dusp14 significantly aggravated cardiac hypertrophy, fibrosis, ventricular dilation and dysfunction, whereas transgenic cardiac-specific Dusp14 overexpression significantly attenuated AB-induced cardiac dysfunction and remodeling. In vitro, adenoviral overexpression of constitutive Dusp14 blocked angiotensin II-induced hypertrophic growth of cardiomyocytes, while Dusp14 knockdown led to opposite effects. Mechanistically, excessive phosphorylation of TAK1, P38MAPK and JNK1/2 was evidenced in Dusp14-/- knockout mice post-AB and inactivation of TAK1-P38MAPK and -JNK1/2 signaling using TAK1 inhibitor 5Z-7-ox shares similar antihypertrophic effect as Dusp14 overexpression. Moreover, we show that Dusp14 directly interacted with TAK1. Results from present experiments indicate that Dusp14 protects the heart from AB-induced cardiac hypertrophy and dysfunction possibly through inactivation of TAK1-P38MAPK/-JNK1/2 signaling pathway. Future studies are warranted to test the feasibility of overexpressing Dusp14 as a therapeutic strategy to attenuate cardiac hypertrophy and failure.

Background Previous studies have demonstrated that WenXin KeLi (WXKL), a traditional Chinese medicine, can exert antiarrhythmic properties through complex multichannel inhibition, but its pharmacologic effect remains to be elucidated, especially in the cardiac conductive system. Objective To explore the antiarrhythmic property of WXKL in cardiac Purkinje cells (PCs). Methods PCs were isolated from rabbit hearts and action potentials (APs) and ion currents were recorded by whole-cell patch clamp technique. Anemonia toxin II (ATX-II) and isoproterenol (ISO) were used to induce early or delayed afterdepolarizations (EADs, DADs) or triggered activities (TAs). Results WXKL (1 g/L and 5 g/L) significantly abbreviated the action potential duration (APD) of PCs in a dose- and rate-dependent manner. Treatment of PCs with ATX-II (2 nM) prolonged APD and induced EADs, which were significantly suppressed by WXKL. WXKL (1, 5 g/L) also inhibited ISO-induced EADs, DADs, and TAs. To reveal the ionic mechanisms, we studied the effects of WXKL on late sodium current (I NaL ), peak sodium current (I NaP ), and L-type calcium currents (I CaL ) in PCs. WXKL-attenuated ATX-II (5 nM) induced I NaL augmentation and blocked I NaL with an IC 50 of 4.3 ± 0.5 g/L, which is 3- to 4-fold more selective than that of I NaP (13.3 ± 0.9 g/L) and I CaL (17.6 ± 1.4 g/L). Moreover, WXKL exerted significantly less use-dependent block of I NaP than that of flecainide, indicating its lower proarrhythmic effect. Conclusions WXKL exhibits antiarrhythmic properties in cardiac PCs via selective inhibition of I NaL .

The purpose of this study was to test the efficacy of Berberine (Ber) on atrial fibrillation (AF) induced by acetylcholine (ACh) and explore its underlying mechanisms of action. In vivo electrophysiology experiments were performed in adult anesthetized rabbits. Single atrial myocytes were isolated from rabbit hearts and action potentials recorded using patch clamp techniques. AF was induced by rapid atrial burst pacing during intravenous (IV) ACh infusion alone or with IV Ber. Compared to the Baseline, IV Ber (2 mg/kg) prolonged the RR interval and effective refractory period (195 ± 10 vs. 215 ± 11 msec; 80 ± 4 vs. 85 ± 5 msec, respectively; both P

Activin receptor-like kinase 4 (ALK4), a downstream receptor of transforming growth factor-β superfamily, is highly expressed in the mammal heart. We recently reported that ALK4 is upregulated in pressure-overloaded heart and ALK4 haplodeficiency attenuated the pressure overload-induced cardiac

Background: Hydrogen peroxide (H2O2)-induced oxidative stress has been demonstrated to induce afterdepolarizations and triggered activities in isolated myocytes, but the underlying mechanisms remain not fully understood. We aimed to explore whether protein kinase C (PKC) activation plays an important role in oxidative stress-induced afterdepolarizations. Methods: Action potentials and ion currents of isolated rabbit cardiomyocytes were recorded using the patch clamp technique. H2O2 (1 mM) was perfused to induce oxidative stress and the specific classical PKC inhibitor, Gö 6983 (1 μM), was applied to test the involvement of PKC. Results: H2O2 perfusion prolonged the action potential duration and induced afterdepolarizations. Pretreatment with Gö 6983 prevented the emergence of H2O2-induced afterdepolarizations. Additional application of Gö 6983 with H2O2 effectively suppressed H2O2-induced afterdepolarizations. H2O2 increased the late sodium current (INa,L) (n = 7, p < 0.01) and the L-type calcium current (ICa,L) (n = 5, p < 0.01), which were significantly reversed by Gö 6983 (p < 0.01). H2O2 also increased the transient outward potassium current (Ito) (n = 6, p < 0.05). However, Gö 6983 showed little effect on H2O2-induced enhancement of Ito. Conclusions: H2O2 induced afterdepolarizations via the activation of PKC and the enhancement of ICa,L and INa,L. These results provide evidence of a link between oxidative stress, PKC activation and afterdepolarizations.

Non-cement femoral stems are recognized in clinical use, but there are still some problems. The aim of this research was to make non-cement femoral stems to be press-fit with the medullary cavity.Twenty-four healthy adult mongrel dogs were randomly divided into experimental and control groups. In the right hip joint, an artificial femoral bone replacement surgery was conducted. For the experimental group, the replacement surgery of hydroxyapatite (HA)-coated femoral stems was done, while autogeneous morselized bone was implanted into the medullary cavity. For the control group, morselized bone was not implanted. At postoperative 1, 3, 6 months, a test for interfacial shear characteristics was conducted in the MTS810 Tester. The comparison between the two groups' bone-prostheses in shear strength for their interface from shearing destruction was made. A histological observation to check prosthesis-bone interface contact ratios and bone growth was carried out.For the experimental group, shear strength was 0.317 MPa in 1 month, 1.447 MPa in 3 months, and 1.621 MPa in 6 months. For the control group, shear strength was 0.195 MPa in 1 month, 1.023 MPa in 3 months, and 1.483 MPa in 6 months. The difference was statistically significant. Stereomicroscope-based observation showed that the number of trabecular bones in the experimental group was larger than that of the control group, and bone growth of the former group was better than that of the latter group. Inverted microscopic observation showed that the binding degree between the prosthesis and trabecular bone of the experimental group was higher than that of the control group. Comparatively, the experimental group's trabecular bone had more stromal cells.The morselized bones can effectively improve the biological bonding strength and bone-contact ratios in the short term for the HA-coated femoral stem and accelerate the bonding process. The use of morselized autogenous bones played a good role in bone in-growth of the femoral bone stem surface.

Intracytoplasmic sperm injection (ICSI) and other assisted reproductive technologies (ART) are effective treatments for infertility and are widely used at infertility clinics. Although ICSI is generally considered safe, some studies have suggested an excess occurrence of major birth defects resulting from the procedure. Here, we present a rare case of a boy with multiple orofacial malformations who was conceived by ICSI. We suggest therefore that the risk of genetics abnormalities should be discussed in detail with the parents and sufficient informed consent should be obtained before starting ICSI procedures.

Aims Myocardial infarction (MI) induces neural remodelling of the left stellate ganglion (LSG), which may contribute to ischaemia-induced arrhythmias. The neural chemorepellent Semaphorin 3a (Sema3a) has been identified as a negative regulator of sympathetic innervation in the LSG and heart. We previously reported that overexpression of Sema3a in the border zone could reduce the arrhythmogenic effects of cardiac sympathetic hyperinnervation post-MI. This study investigated whether Sema3a overexpression within the LSG confers an antiarrhythmic effect after MI through decreasing extra- and intra-cardiac neural remodelling. Methods and results Sprague-Dawley rats were subjected to MI, and randomly allocated to intra-LSG microinjection of either phosphate-buffered saline (PBS), adenovirus encoding green fluorescent protein (AdGFP), or adenovirus encoding Sema3a (AdSema3a). Sham-operated rats served as controls. Two weeks after infarction, MI-induced nerve sprouting and sympathetic hyperinnervation in the LSG and myocardium were significantly attenuated by intra-LSG injection with AdSema3a, as assessed by immunohistochemistry and western blot analysis of growth-associated protein 43 and tyrosine hydroxylase. This was also confirmed by sympathetic nerve function changes assessed by cardiac norepinephrine content. Additionally, intra-LSG injection with AdSema3a alleviated MI-induced accumulation of dephosphorylated connexin 43 in the infarct border zone. Furthermore, Sema3a overexpression in the LSG reduced the incidence of inducible ventricular tachyarrhythmia by programmed electrical stimulation post-MI, and arrhythmia scores were significantly lower in the AdSema3a group than in the PBS and AdGFP groups. Conclusion Semaphorin 3a overexpression in the LSG ameliorates the inducibility of ventricular arrhythmias after MI, mainly through attenuation of neural remodelling within the cardiac-neuraxis.