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Infective endocarditis (IE) in the pediatric population can present as a life-threatening condition. Optimal timing for surgical intervention should consider surgical risks versus the risk of neurologic complications. We herein report our experience with this group of critically ill children. Retrospective analysis of patient charts of all patients who underwent urgent surgical treatment of aortic IE from 1994 to 2014 was performed. Nine patients with acute storming IE of the aortic valve or the ascending aorta were urgently operated (eight normal heart, one congenital aortic stenosis), age ranged from 8 weeks to 4.2 years. Causative organisms were Staphylococcus aureus (2), Staphylococcus coagulase negative (1), Kingella kingae (2), Streptococcus pneumoniae (2), or culture negative (2). Presenting symptoms other than hemodynamic instability were neurologic decompensation (5) coronary embolization (1) and cardiogenic shock due to scalded skin syndrome (1). CT and MRI demonstrated significant brain infarcts in four patients. Operations performed were the Ross operation (7) and ascending aortic reconstruction (2). There were no operative deaths. At a median follow-up of 6 years (range 2-196 months), all patients are alive and well. Re-intervention included homograft replacement (2) and transcatheter Melody valve implantation (1). At their last follow-up, the neo-aortic valve was functional in all patients with minimal regurgitation and all had full resolution of the neurological deficits. Urgent surgical treatment for aortic valve IE in infants is challenging. Although surgery is complex and pre-disposing conditions such as sepsis, neurologic and cardiac decompensations are prevalent, operative results are excellent and gradual and significant neurologic improvement was noted over time.

Background Limited fluoroscopy ablation using 3D electro-anatomical system (3DS) has been used for arrhythmias in children, however it is not a common practice. We aimed to facilitate a fluoroscopy limited approach for ablation of accessory pathways (AP) in children. Methods Following electrophysiologic (EP) catheter placement a single dual-plane fluoroscopic image (right anterior oblique-30° and left anterior oblique-60° views) was acquired and the 3DS views were rotated to be a perfect match to the fluoroscopy. Ninety-four consecutive pediatric patients [mean age 11.8 ± 4.1 (4.2–18) years, 61.7% males] with Wolf–Parkinson–White syndrome underwent ablation of an AP. Fifty-seven had manifest AP, 54 had left-sided AP (LSAP) and 40 had right-sided AP (RSAP). Results The acute success rate was 95.7% (90/94), with a recurrence rate of 1.1% (1/90) at a mean follow-up of 13 ± 5.5 (4.4–22.9) months. Mean procedure and fluoroscopy times were 144 ± 45 (55–262) min and 1.8 ± 1.4 (0.1–5.6) min, respectively. Comparison of the first 20 procedures to the next 74 procedures demonstrated an extended procedure time (171 ± 53 min vs 135 ± 38 min, p

Because of its safety profile, cryoablation has become an alternative therapy for septal arrhythmias, including parahisian accessory pathways (APs). Data regarding its efficacy, safety, and late outcome for parahisian APs in children are limited.The purpose of this study was to evaluate the safety and efficacy of cryoablation of parahisian APs in children.Fifty-nine cryoablations of parahisian APs were performed in 50 patients [76% males; median age 16.5 years (range 5.3-20 years)]. Thirty-three had manifest APs and 17 had concealed APs. The time to effect was defined as the duration of time from reaching -30°C to the disappearance of AP during the cryomapping phase. The acute success rate for the first ablation was 94% (47/50).Mean fluoroscopy time and number of cryoablations were 28.5 ± 23.3 minutes and 2.6 ± 1.2 seconds, respectively. The time to effect was 8.5 ± 7.1 seconds. The overall recurrence rate was 14.9%, decreasing from 40% in the first 10 cases to 8.1% in the next 37 (P.02). Multivariate analysis showed that the only independent predictor for recurrence rate was time to effect10 seconds (P.001). A high recurrence rate was also associated with concealed APs and ablation during supraventricular tachycardia (P.03 and P.05, respectively). The patients who had recurrence underwent a second successful cryoablation. During median follow-up of 59.7 months (range 6-102 months), a long-term success rate of 94% was achieved. No permanent ablation-related complications occurred.Cryoablation of parahisian APs has excellent short- and long-term efficacy and safety profile. Increased physician experience is associated with a reduced recurrence rate.

Background Limited fluoroscopy cryo-ablation using a 3D electro-anatomical system (3DS) has been used for AVNRT in children. We aimed to facilitate a fluoroscopy limited approach of RF ablation of AVNRT in children. Methods A retrospective study was performed of procedure parameters in children undergoing RF ablation of AVNRT in 75 consecutive children (June 2011 to November 2013 — Group A) using standard fluoroscopy techniques compared to those of 64 consecutive children (December 2013 to May 2015 — Group B), using a fluoroscopy limited approach with 3DS. Results The acute success rate was 98.7% (74/75) and 98.4% (63/64) for groups A and B, respectively. The recurrence rate was 2.7% (2/74) and 0% (0/63) with a mean follow-up period of 45.5±12.1 and 14.3±6.1months for group A and group B, respectively. The mean procedure and fluoroscopy times were significantly lower for group B compared to group A (119±37 (43–203) and 0.83±1.04 (0.05–3.83) minutes versus 146±53 (72–250) and 16.1±8.9 (4.39–55) minutes, p p Conclusions A fluoroscopy limited approach for RF ablation of AVNRT in children using a 3DS is easily acquired and adapted, and significantly reduces the fluoroscopy and procedure time with excellent efficacy, safety and low recurrence rate. Condensed ABSTRACT This study confirmed that a 3D mapping system (3DS) to guide ablations of AVNRT in children reduces radiation exposure. Combined, limited fluoroscopy and 3DS in a methodology that resembles the familiar conventional fluoroscopy approach for RF ablation of AVNRT in children is proposed. Combined limited fluoroscopy and RF-energy in children with AVNRT are associated with a shorter procedure time, minimal fluoroscopy time, a high success rate and a low recurrence rate.

Homozygosity mapping was performed in a consanguineous Sephardic Jewish family with three patients who presented with severe infantile encephalopathy associated with pontocerebellar hypoplasia and multiple mitochondrial respiratory-chain defects. This resulted in the identification of an intronic mutation in RARS2, the gene encoding mitochondrial arginine-transfer RNA (tRNA) synthetase. The mutation was associated with the production of an abnormally short RARS2 transcript and a marked reduction of the mitochondrial tRNA(Arg) transcript in the patients' fibroblasts. We speculate that missplicing mutations in mitochondrial aminoacyl-tRNA synthethase genes preferentially affect the brain because of a tissue-specific vulnerability of the splicing machinery.

Major involvement of CD40 in the regulation of chemokine secretion from human peritoneal mesothelial cells. Background CD40 is a member of the tumor necrosis factor (TNF) family of receptors, whose ligand, CD154, is expressed by activated mononuclear cells. CD40 activation is a major immune regulatory pathway and is important for the regulation of chemokine and cytokine secretion. This study investigates the effect of CD40 ligation on the secretion of chemokines from human peritoneal mesothelial cells (HPMC). Methods We activated CD40 in HPMC along with combinations of TNF-α, interleukin-1 (IL-1), and interferon gamma (IFN-γ), and evaluated the mRNA levels and protein secretion of regulated upon activation, normal T-cell expressed and secreted (RANTES), monocyte chemoattractant protein-1 (MCP-1), and IL-8. Results CD40 ligation had a small stimulatory effect on the secretion of all three chemokines, while TNF-α, IL-1 and IFN-γ induced their secretion in a dose-dependent manner. The combination of CD40 ligation with either IL-1 or TNF-α increased chemokine secretion additively. IFN-γ and CD40 ligation acted in synergy to induce the secretion of the mononuclear recruiting chemokines RANTES and MCP-1 (up to ∼36-fold and ∼ threefold, respectively), for which the combination of all three cytokines with CD40 ligation was extremely potent. In contrast, the secretion of the neutrophil chemoattractant IL-8, induced by CD40 ligation or by the combination of IL-1 and TNF-α, was reduced in the presence of IFN-γ. Conclusion In light of our data, it is reasonable to suggest that in the mononuclear phase of peritonitis, IFN-γ and CD154, expressed by activated mononuclear cells, diminish IL-8 secretion from HPMC and thus inhibit neutrophil recruitment. At the same time, the two act in synergy to induce the secretion of RANTES and MCP-1 from HPMC. Hence, by regulating chemokine secretion, CD40 may be involved in peritonitis and in the development of late phase mononuclear predominance.

Correction of anemia in uremic mice by genetically modified peritoneal mesothelial cells. Background During peritoneal dialysis, mesothelial cells become detached from the peritoneum and accumulate in the dialysate. Our aim was to evaluate the potential of peritoneal effluent (PF)-derived human peritoneal mesothelial cells (HPMC) as target for gene therapy. We used erythropoietin (EPO) as our target gene. Methods Various extracellular matrixes (ECM) were tested for optimal adhesion and growth of HPMC. The EPO gene was introduced to mouse peritoneal mesothelial cells (MPMC) and HPMC by transfection or retroviral transduction. EPO secretion from PMC was measured by enzyme-linked immunosorbent assay (ELISA) and by the TF-1 cell proliferation assay. We performed intraperitoneal or intramuscular transplantations of the genetically modified cells into regular or 5/6 nephrectomized Balb/c mice and nude mice. Finally, we measured serum EPO and hematocrit levels. Results ECM-coated plates provided up to sixfold increase in the efficiency of PMC isolation from PF. Gelatin coated dishes (20 μg/cm 2 ) were found optimal for isolation of PF-HPMC. RPR-120535 liposome was found to be best for PMC transduction. In vitro studies showed EPO secretion from modified HPMC over 6 months. Intraperitoneal transplantation aided with collagen matrix was the most effective. EPO, in MPMC transplanted mice, was detected up to 3 weeks (peak at 13 ± 1 mIU/mL), and anemia of uremic mice was corrected (35.3 ± 0.9 mIU/mL to 41.9 ± 1.1 mIU/mL). Conclusion PF-HPMC can be considered as an appropriate target for gene therapy since these cells can be efficiently isolated, modified, and transplanted. Nevertheless, implantation techniques in the peritoneum should be directed at obtaining longer duration of transgene expression in vivo, and means should be developed for enabling regulated expression of the gene.

TNF-receptors on human peritoneal mesothelial cells: Regulation of receptor levels and shedding by IL-1 α and TNF α . Human peritoneal mesothelial cells (HPMC) respond to tumor necrosis factor α (TNF α ) by releasing various cytokines that may activate the endothelium and induce recruitment of leukocytes during peritonitis. We characterized the receptors for TNF on HPMC to elucidate their functions in peritonitis. Scatchard analysis determined the presence of 70 × 10 3 TNF receptors/cell with a kDa of 0.44 n m . TNF receptor 1 (TNF-R1, p55) and TNF-R2 (p75) mRNA were demonstrated by reverse-transcriptase-PCR (RT-PCR). TNF-R1 protein was solely detected by flow cytometry (FCM). Interleukin-1 α (IL-1 α ) induced down-regulation of TNF-R1. This was concomitant with accumulation of soluble TNF-R1 (sTNF-R1) detected by specific ELISA. LPS had a lower TNF-R1-shedding activity while TNF α did not induce shedding. The IL-1-induced-sTNF-R1-shedding was suppressed by the protein-kinase-A (PKA) inhibitor, H-8, or by H-7, the inhibitor of both PKC and PKA, but not by the specific PKC inhibitor GF. These experiments suggest a role for PKA in the IL-1-shedding signal. No change in TNF-R1 mRNA levels was observed after IL-1 α or TNF α stimulation while TNF-R2 (p75) mRNA basal levels transiently increased three to fivefold, reaching a peak after four hours followed by an accumulation of sTNF-R2 in the supernatant. Our data suggest that the main receptor expressed on HPMC is TNF-R1. Down-regulation and shedding of TNF-R1 induced by IL-1, and the transient expression of TNF-R2 induced by IL-1 and TNF, may regulate the responses to TNF by HPMC. These results may be important in understanding the inflammatory process of peritonitis were TNF plays a major role.

Background Significant advancements in understanding the molecular pathophysiology of laterality determination were recently made. However, there are large gaps in our knowledge of the initial processes that lead to laterality defects, such as heterotaxy syndrome (HS, also known as situs ambiguous) and situs inversus totalis (SIT). The former refers to abnormal distribution of visceral organs, and the latter refers to a complete laterality inversion of both abdominal and thoracic viscera. Methods In order to identify a mutated gene in SIT and HS patients, the authors performed homozygosity mapping in a consanguineous family with laterality disorders identified in two siblings. Results A homozygous deleterious mutation in the CCDC11 gene was identified in the patients. The mutation resulted in an abnormally smaller protein in the patient9s skin fibroblasts. The parents and five healthy siblings were heterozygous for the mutation, which was not present in 112 anonymous controls. Conclusions Few genes have been associated with both SIT and HS, usually accompanied by other abnormalities. The authors suggest that CCDC11 is associated with autosomal recessive laterality defects of diverse phenotype resulting in SIT in one individual family member who is otherwise healthy, and in complex laterality anomalies (HS) in another member. This report underscores the importance of CCDC11 in laterality determination.

This is a report of a child with Brugada syndrome who experienced ventricular fibrillation storm. Initial presentation was atrial fibrillation without the Brugada-type electrocardiogram, aborted cardiac arrest and positive family history of sudden death.

Many renal diseases, including transplant rejection, are mediated by mononuclear cells. Interleukin-15 (IL-15) has been recently described as a cytokine with IL-2-like activity. IL-15 is an effective leukocyte growth factor, activator, and chemoattractant. In rejected human kidney allografts, elevated IL-15, but not IL-2, mRNA is expressed, suggesting a role for IL-15 in the rejection process. The aim of this study was to investigate whether human cortical tubular epithelial cells (HTC) are able to produce IL-15 and whether IL-15 expression is regulated by inflammatory mediators. HTC were isolated and characterized, and IL-15 expression was analyzed by reverse transcription-PCR, enzyme-linked immunosorbent assay, and bioactivity. It was found that HTC constitutively express IL-15. Upon stimulation of HTC with interferon-gamma (IFN gamma), the levels of both mRNA and protein increased up to twofold. In contrast, lipopolysaccharide, IL-1, IL-2, and tumor necrosis factor-alpha had no detectable effect. IFN gamma action on HTC was dose-dependent from concentrations of 5 U/ml, reaching a plateau at 50 U/ml. HTC supernatants induced proliferation of the T cell line CTLD, which could be partially blocked (50%) by specific IL-15 antibodies. This study shows that IL-15 is secreted by HTC and that the Th1-cytokine IFN gamma upregulates IL-15 expression. This suggests that HTC play a role in cell-mediated renal diseases by releasing IL-15.