Morphological and Molecular Changes during Limb Regeneration of the Exopalaemon carinicauda.

With the increase in breeding density of Exopalaemon carinicauda, appendage breakage may occur, which seriously affects survival and economic benefits. To study the limb regeneration process of E. carinicauda, we induced autotomy of the pereopods. After a period of time, wound swelling disappeared, the pigment gradually accumulated, and a tawny film subsequently formed in the wound. The healing period of the wound occurred 24 h after autotomy, and the blastema formation stage occurred 48 h after autotomy. After 4 days of cutting, the limb buds began to differentiate, grow, and expand rapidly, and this process lasted approximately 15 days. Microscopic observations revealed significant changes in the type and number of associated cells including outer epithelial cells, granulocytes, embryonic cells, columnar epidermal cells, elongated cells, and blastoma cells, during the process from limb fracture to regeneration. A comparative transcriptome analysis identified 1415 genes differentially expressed between the J0h (0 h post autotomy) and J18h (18 h post autotomy), and 3952 and 4366 differentially expressed genes for J0 and J14d (14 days post autotomy) and J18h and J14d, respectively. Some of these genes may be related to muscle growth or molting, as indicated by the presence of troponin C, chitinase, actin, innexin, and cathepsin L. As a functional gene involved in epidermal formation, the mRNA expression level of the innexin inx2 in the pereopod of E. carinicauda changed significantly in the experimental groups (p < 0.05). The results of this study contribute to existing knowledge of regeneration mechanisms in crustaceans.

Outcomes of atrial septostomy and effect on long-term survival in patients with idiopathic pulmonary arterial hypertension: A single-center cohort.

OBJECTIVE: Pulmonary arterial hypertension (PAH) is a chronic progressive disease that may lead to right heart failure (RHF) and early death. Balloon atrial septostomy (BAS) may be used for the palliative treatment of RHF from PAH. We present our contemporary institutional experience of utilizing BAS in idiopathic PAH (IPAH) patients with refractory RHF to investigate the effect on the safety, efficacy and long-term survival. METHODS: This retrospective analysis included 12 IPAH patients with severe RHF from March 2017 to May 2019 who were assessed as high risk. All patients received standard treatment including combination of PAH-specific drugs. Graded BAS was performed on these patients due to unsatisfactory clinical response. Clinical, functional and hemodynamic variables before and immediately after the procedure were collected. 1-year follow-up outcomes and 3-year survival rate were further analyzed. RESULTS: Successful septostomy was achieved in cases with no procedure-related complications. All patients obtained hemodynamic improvement immediately after the procedure. The WHO functional class and exercise endurance improved at 1-year follow-up, 7 of 12 patients achieved intermediate-low risk status, while the rest remained at intermediate-high risk. 2 patients died at 18 and 20 months due to malignant arrhythmia and advanced heart failure, respectively. Survival at 1 year and 3 years was 100% and 83.3%. CONCLUSIONS: In selected IPAH patients with refractory RHF, BAS is an additional therapeutic strategy, especially when PAH-specific drugs could not achieve the treatment target. BAS can improve hemodynamic variables, bring clinical and cardiac functional benefits and increase the 3-year survival.

Pitx controls amphioxus asymmetric morphogenesis by promoting left-side development and repressing right-side formation.

BACKGROUND: Left-right (LR) asymmetry is an essential feature of bilateral animals. Studies in vertebrates show that LR asymmetry formation comprises three major steps: symmetry breaking, asymmetric gene expression, and LR morphogenesis. Although much progress has been made in the first two events, mechanisms underlying asymmetric morphogenesis remain largely unknown due to the complex developmental processes deployed by vertebrate organs. RESULTS: We here addressed this question by studying Pitx gene function in the basal chordate amphioxus whose asymmetric organogenesis, unlike that in vertebrates, occurs essentially in situ and does not rely on cell migration. Pitx null mutation in amphioxus causes loss of all left-sided organs and incomplete ectopic formation of all right-sided organs on the left side, whereas Pitx partial loss-of-function leads to milder phenotypes with only some LR organs lost or ectopically formed. At the N1 to N3 stages, Pitx expression is gradually expanded from the dorsal anterior domain to surrounding regions. This leads to activation of genes like Lhx3 and/or Prop1 and Pit, which are essential for left-side organs, and downregulation of genes like Hex and/or Nkx2.1 and FoxE4, which are required for right-side organs to form ectopically on the left side. In Pitx mutants, the left-side expressed genes are not activated, while the right-side genes fail to decrease expression on the left side. In contrast, in embryos overexpressing Pitx genes, the left-side genes are induced ectopically on the right side, and the right-side genes are inhibited. Several Pitx binding sites are identified in the upstream sequences of the left-side and right-side genes which are essential for activation of the former and repression of the latter by Pitx. CONCLUSIONS: Our results demonstrate that (1) Pitx is a major (although not the only) determinant of asymmetric morphogenesis in amphioxus, (2) the development of different LR organs have distinct requirements for Pitx activity, and (3) Pitx controls amphioxus LR morphogenesis probably through inducing left-side organs and inhibiting right-side organs directly. These findings show much more dependence of LR organogenesis on Pitx in amphioxus than in vertebrates. They also provide insight into the molecular developmental mechanism of some vertebrate LR organs like the lungs and atria, since they show a right-isomerism phenotype in Pitx2 knockout mice like right-sided organs in Pitx mutant amphioxus. Our results also explain why some organs like the adenohypophysis are asymmetrically located in amphioxus but symmetrically positioned in vertebrates.

Strategy of catheter ablation for para-Hisian premature ventricular contractions with the assistance of remote magnetic navigation.

INTRODUCTION: Catheter ablation of frequent para-Hisian premature ventricular contractions (PH-PVCs) is considered to be challenging. The purpose of this study was to evaluate the strategy, potential technical advantages, and clinical outcomes of remote magnetic navigation (RMN) in the ablation of PH-PVCs. METHODS: Fifteen consecutive patients with PH-PVCs were included in this study. Electrical mapping was initially performed in the right ventricular septum by manipulating the RMN catheter with a "U-curve." In the case of no optimal ablation site or ablation failure, the ablation catheter was directed to the left ventricular (LV) septum through a transseptal approach for further mapping and ablation by manipulating the RMN catheter with a "reverse S-curve." RESULTS: Nine of 15 patients were submitted to ablation on the right side. However, ablation success was only achieved in only three (33%) cases. Of the other 12 patients, 11 underwent LV mapping and ablation. In this subset, 9 of 11 (82%) PH-PVCs were totally eliminated on the left side. Overall, RMN-guided mapping and ablation successfully eliminated 12 (80%) of 15 idiopathic PH-PVCs. During follow-up, the reoccurrence of PVCs was reported in 1 (8%) of 12 patients. No atrioventricular block was observed during or after the procedure. CONCLUSION: RMN-guided catheter ablation for PH-PVCs is effective and safe in unselected patients. Due to the excellent reachability and contact with special morphologies of the RMN catheter on both sides of the ventricular septum, RMN can be considered an effective approach for frequent PH-PVCs.

Comparison of efficacy and safety of laser balloon and cryoballoon ablation for atrial fibrillation-a meta-analysis.

BACKGROUND: Laser balloon (LB) and cryoballoon (CB) ablation are two balloon-based catheter ablation technologies used for atrial fibrillation (AF) ablation in recent years. However, the efficacy and the safety of LB ablation in comparison to CB ablation remained indeterminate. We sought to compare these two technologies by conducting meta-analysis of previous studies using both the CB and LB ablation systems for AF ablation. METHODS: We searched electronic scientific databases for studies of LB vs. CB ablation in AF patients. The procedural efficacy was assessed by the success of acute pulmonary vein isolation (PVI) and the 12-month recurrence of any atrial arrhythmia, and the safety was evaluated by the risk of procedure-related complications. RESULTS: A total of 595 participants (LB, n = 292 vs. CB, n = 303) from eight studies were included in this meta-analysis. Risk of acute PVI failure (risk ratio, RR 95% confidence interval [95% CI] = 2.55 [0.86-7.56], P = 0.09) and atrial arrhythmia recurrence in 12 months (RR [95% CI] = 0.91 [0.64-1.28], P = 0.59) were comparable between LB vs. CB ablation, and LB ablation tended to be more effective than CB ablation in paroxysmal AF patients (RR [95% CI] = 0.70 [0.47-1.03], P = 0.07). Risk of procedure-related complications was similar while LB ablation showed slightly higher risk without statistic significance (LB 13.9% vs. CB 9.3%, RR [95% CI] = 1.52 [0.88-2.64], P = 0.14). Compared with CB ablation, LB ablation led to longer procedure duration (weighted mean differences WMD [95% CI] =29.7 [15.8-43.7], P < 0.001) while similar fluoroscopy duration was observed between these two ablation devices (WMD [95% CI] = - 1.99[- 6.46-2.47], P = 0.38). CONCLUSIONS: LB ablation has a trend toward higher procedural efficacy compared with CB ablation in paroxysmal AF patients. However, longer procedure duration and a statistically non-significant trend of more procedure-related complications were also observed in patients ablated by LB. Further larger comparative randomized trials are warranted to disclose the impact of LB compared with CB for ablation of AF.