BLZ8 activates a plastidial peroxiredoxin and a ferredoxin to protect Chlamydomonas reinhardtii against oxidative stress

Reactive oxygen species (ROS) cause damage to various cellular processes in almost all organisms, in particular photosynthetic organisms that depend on the electron transfer chain for CO2 fixation. However, the detoxifying process to mitigate ROS damage has not been studied intensively in microalgae. Here, we characterized the ROS detoxifying role of a bZIP transcription factor, BLZ8, in Chlamydomonas reinhardtii. To identify downstream targets of BLZ8, we carried out comparative genome-wide transcriptomic profiling of BLZ8 OX and its parental CC-4533 under oxidative stress conditions. Luciferase reporter activity assays and RT-qPCR were performed to test whether BLZ8 regulates downstream genes. We performed an in silico functional gene network analysis and an in vivo immunoprecipitation assay to identify the interaction between downstream targets of BLZ8. Comparative transcriptomic analysis and RT-qPCR revealed that overexpression of BLZ8 increased the expression levels of plastid peroxiredoxin1 (PRX1) and ferredoxin-5 (FDX5) under oxidative stress conditions. BLZ8 alone could activate the transcriptional activity of FDX5 and required bZIP2 to activate transcriptional activity of PRX1. Functional gene network analysis using FDX5 and PRX1 orthologs in A. thaliana suggested that these two genes were functionally associated. Indeed, our immunoprecipitation assay revealed the physical interaction between PRX1 and FDX5. Furthermore, the complemented strain, fdx5 (FDX5), recovered growth retardation of the fdx5 mutant under oxidative stress conditions, indicating that FDX5 contributes to oxidative stress tolerance. These results suggest that BLZ8 activates PRX1 and FDX5 expression, resulting in the detoxification of ROS to confer oxidative stress tolerance in microalgae.

An anti-TL1A antibody for the treatment of asthma and inflammatory bowel disease

TL1A is an attractive therapeutic target for the treatment of mucosal inflammation associated with inflammatory bowel disease (IBD) and asthma. Blockade of the TL1A pathway has been shown to reduce inflammatory responses while leaving baseline immunity intact, and to be beneficial in animal models of colitis and asthma. Given the therapeutic potential of blocking this pathway in IBD and asthma, we developed C03V, a human antibody that binds with high affinity to soluble and membrane-bound TL1A. In an assay measuring apoptosis induced by exogenous TL1A, C03V was 43-fold more potent than the next most potent anti-TL1A antibody analyzed. C03V also potently inhibited endogenous TL1A activity in a primary cell-based assay. This potency was linked to the C03V-binding epitope on TL1A, encompassing the residue R32. This residue is critical for the binding of TL1A to its signaling receptor DR3 but not to its decoy receptor DcR3, and explains why C03V inhibited TL1A-DR3 binding to a much greater extent than TL1A-DcR3 binding. This characteristic may be advantageous to preserve some of the homeostatic functions of DcR3, such as TL1A antagonism. In colitis models, C03V significantly ameliorated microscopic, macroscopic and clinical aspects of disease pathology, and in an asthma model it significantly reduced airways inflammation. Notable in both types of disease model was the reduction in fibrosis observed after C03V treatment. C03V has the potential to address unmet medical needs in asthma and IBD.

Potent neutralizing anti-CD1d antibody reduces lung cytokine release in primate asthma model

CD1d is a receptor on antigen-presenting cells involved in triggering cell populations, particularly natural killer T (NKT) cells, to release high levels of cytokines. NKT cells are implicated in asthma pathology and blockade of the CD1d/NKT cell pathway may have therapeutic potential. We developed a potent anti-human CD1d antibody (NIB.2) that possesses high affinity for human and cynomolgus macaque CD1d (K_D ∼100 pM) and strong neutralizing activity in human primary cell-based assays (IC₅₀ typically <100 pM). By epitope mapping experiments, we showed that NIB.2 binds to CD1d in close proximity to the interface of CD1d and the Type 1 NKT cell receptor β-chain. Together with data showing that NIB.2 inhibited stimulation via CD1d loaded with different glycolipids, this supports a mechanism whereby NIB.2 inhibits NKT cell activation by inhibiting Type 1 NKT cell receptor β-chain interactions with CD1d, independent of the lipid antigen in the CD1d antigen-binding cleft. The strong in vitro potency of NIB.2 was reflected in vivo in an Ascaris suum cynomolgus macaque asthma model. Compared with vehicle control, NIB.2 treatment significantly reduced bronchoalveolar lavage (BAL) levels of Ascaris-induced cytokines IL-5, IL-8 and IL-1 receptor antagonist, and significantly reduced baseline levels of GM-CSF, IL-6, IL-15, IL-12/23p40, MIP-1α, MIP-1β, and VEGF. At a cellular population level NIB.2 also reduced numbers of BAL lymphocytes and macrophages, and blood eosinophils and basophils. We demonstrate that anti-CD1d antibody blockade of the CD1d/NKT pathway modulates inflammatory parameters in vivo in a primate inflammation model, with therapeutic potential for diseases where the local cytokine milieu is critical.

A Role for Gut Microbiota and the Metabolite-Sensing Receptor GPR43 in a Murine Model of Gout

OBJECTIVE

Host-microbial interactions are central in health and disease. Monosodium urate monohydrate (MSU) crystals cause gout by activating the NLRP3 inflammasome, leading to interleukin-1β (IL-1β) production and neutrophil recruitment. This study was undertaken to investigate the relevance of gut microbiota, acetate, and the metabolite-sensing receptor GPR43 in regulating inflammation in a murine model of gout.

METHODS

Gout was induced by the injection of MSU crystals into the knee joints of mice. Macrophages from the various animals were stimulated to determine inflammasome activation and production of reactive oxygen species (ROS).

RESULTS

Injection of MSU crystals caused joint inflammation, as seen by neutrophil influx, hypernociception, and production of IL-1β and CXCL1. These parameters were greatly decreased in germ-free mice, mice treated with antibiotics, and GPR-43-deficient mice. Recolonization or administration of acetate to germ-free mice restored inflammation in response to injection of MSU crystals. In vitro, macrophages produced ROS and assembled the inflammasome when stimulated with MSU. Macrophages from germ-free animals produced little ROS, and there was little inflammasome assembly. Similar results were observed in macrophages from GPR-43-deficient mice. Treatment of germ-free mice with acetate restored in vitro responsiveness of macrophages to MSU crystals.

CONCLUSION

In the absence of microbiota, there is decreased production of short-chain fatty acids that are necessary for adequate inflammasome assembly and IL-1β production in a manner that is at least partially dependent on GPR43. These results clearly show that the commensal microbiota shapes the host's ability to respond to an inflammasome-dependent acute inflammatory stimulus outside the gut.

Regulation of immune responses to Strongyloides venezuelensis challenge after primary infection with different larvae doses

Nematode infections are generally followed by high rates of reinfection, leading to elevated prevalence in endemic areas. Therefore, the effective control of nematode infections depends on understanding the induction and regulation of protective mechanisms. However, most experimental models for protective immune response against nematodes use high parasite exposure, not always reflecting what occurs naturally in human populations. In this study, we tested whether infecting mice with different Strongyloides venezuelensis larvae loads would affect protective responses against reinfection. Interestingly, we found that a previous infection with 10-500 larvae conferred high rate of protection against reinfection with S. venezuelensis in mice, by destroying large numbers of migrating larvae. However, low-dose priming did not abolish adult worm maturation, as detected in high-dose primed group. Results also indicated that a previous low-dose infection delayed the development of cellular infiltrate, while a high inoculum rapidly induced these inflammatory features. Cytokine production by splenocyte cultures of challenge infected mice demonstrated that low-dose priming had increased production of IL-4 and IFN-gamma, while high-dose induced IL-4 production but not IFN-gamma. Our data support the hypothesis that low-dose nematode infection does not induce a polarized type-2 immune response, allowing adult worm survival.

Salivary Fluoride from Fluoride Dentifrices or Rinses after Use of a Calcium Pre-Rinse or Calcium Dentifrice

The low concentration of available calcium (Ca) in oral fluids limits the formation of Ca-mediated fluoride deposits that maintain oral fluoride (F) after a topical F treatment. The purpose of this study was to examine if a high concentration of Ca would increase salivary F when used before a F rinse or dentifrice. We found that a Ca pre-rinse (150 mmol/l Ca lactate) or Ca dentifrice (0.084 g Ca glycerolphosphate per gram dentifrice) used immediately before a 60 s 228-ppm F rinse (12 mmol/l NaF) produced a 4.6x or 3.6x increase (p < 0.05) respectively in the 1 h salivary F concentrations over the F rinse alone. Reducing the post-Ca F rinse to 10 s still produced a significant 2.2x increase in salivary F compared to the 60 s F rinse alone. Used with a conventional 1,100 ppm F (i.e. 1,100 microg F per gram) NaF dentifrice (Crest), the above Ca pre-rinse increased 1 h salivary F levels by 2.3x over the F dentifrice alone. However, a F rinse given before a Ca rinse produced no increase in 1 h salivary F concentrations. Although the persistence of these increases requires further study, these results suggest that a moderately high concentration of Ca given shortly before a F rinse or F dentifrice may increase the cariostatic effect of the F product.

Cost-effectiveness of coarctation repair strategies: endovascular stenting versus surgery

The cost-effectiveness of stent (ST) implantation for the repair of coarctation of the aorta (CoA) is not documented in the medical literature. Inflation-adjusted hospital costs for ST implantation and for surgical (SU) repair were obtained using the HBOC Cost Accounting System software and evaluated for all patients 5 years of age or older who underwent elective treatment of CoA between July 1997 and June 2001. The average age of the ST group (n = 10) to 9.5 +/- 3.5 years for the SU group (n = 12) (p > 0.10). The ST group had one failure due to inability to cross the CoA (failure rate, 10%). Successful repair was accomplished in all other ST cases and in all SU cases, with no residual systolic gradients at 1-year follow-up. Hospital length of stay for the ST group was 0.8 +/- 1.2 days compared to 3.5 +/- 0.5 days for the SU group (p < 0.001). The mean inflation-adjusted cost for the ST group was dollar 7,148 +/- 2,984 versus dollar 11,769 +/- 3,702 for the SU group (p < 0.005). By intention to treat analysis, the cost of repair in the ST-first group was dollar 8,325 +/- 3,354 given the 10% failure rate (p < 0.04 vs the SU only group). Sensitivity analysis demonstrates that cost of repair is lower with the ST-first strategy compared to SU only until the failure rate of ST implantation exceeds 39%. Repair of CoA using an endovascular stent strategy is cost-effective compared to conventional surgical repair.

Unique echocardiographic features associated with deployment of the Amplatzer atrial septal defect device

The purpose of this study was to describe the unique echocardiographic findings associated with deployment of the Amplatzer atrial septal defect (ASD) device. Thirty-five patients (2 to 40 years old; 23 female and 12 male patients) underwent echocardiography during attempted ASD closure with the Amplatzer device. Transesophageal and transthoracic echocardiograms were performed during the placement and follow-up of the device, respectively. In 5 patients, the device was not deployed because of transesophageal echocardiography (TEE) findings (an exceedingly large defect in 3 patients, partial obstruction of the upper right pulmonary vein by the device in 1, and complex atrial septal anatomy in 1). In the remaining 30 patients, after deployment but before release, the device distorted the atrial septum from the normal vertical orientation to an oblique transverse orientation. Excessive septal distortion (i.e., > or =90 degrees in 1 patient) was associated with device embolization upon release. In other patients, TEE also identified mild splaying of the device on the aortic wall, mild abutment of the device upon the mitral valve, and temporary partial obstruction of pulmonary vein flow. Color Doppler revealed residual shunts in 21 of 29 patients immediately after release, but in none of 15 patients at 1-year follow-up. Transesophageal echocardiography is essential to ensure proper Amplatzer device placement. Distortion of the atrial septum and Amplatzer device orientation occur before release but resolve on release from the delivery cable. Small residual shunts are common early, but they resolve in 6 to 12 months.

One-year follow-up of the amplatzer device to close atrial septal defects

The early and 1-year follow-up of a single United States center using the Amplatzer atrial septal defect closure device is reported. Complete closure was documented in all patients by 1 year after device implantation.

Exposure to ionizing radiation in children undergoing Amplatzer device placement to close atrial septal defects

To evaluate exposure to ionizing radiation during Amplatzer device occlusion, a prospective study was performed to measure surface entrance radiation dose by thermoluminescent dosimetry (TLD). Between June 1998 and April 1999, dosimetry was carried out on 12 patients with Amplatzer device occlusion of atrial septal defects (n = 10) or Fontan fenestration (n =) and 12 age-matched patients who underwent diagnostic catherization. TLD chips were placed at the posterior (PA) and right lateral (LA) chest wall as well as the thyroid (TH) and gonadal (GN) regions. The Amplatzer group had a median age of 6.4 yr (2.4-12.4 yr) and a median weight of 23.7 kg (15.6-28.9 kg), which were similar (p = NS) to those of the control group, who had a median age of 7.9 yr (3.3-16.2 yr) and a median weight of 29.9 kg (10.6-58.0 kg). Device placement was successful in 11 of 12 patients; one device was removed owing to partial obstruction of the right-upper pulmonary vein. Fluoroscopy times were also similar in the Amplatzer group (23.5 +/- 2.1 min) and the control group (16.4 +/- 3.1 min; P = NS). The measured surface entrance doses of the Amplatzer group was similar (p = NS) to those of the control group in all four regions: PA (4.96 +/- 1.88 vs. 6.07 +/- 2.16 cGy), LA (5.22 +/- 1.68 vs. 3.13 +/- 1.25 cGy), TH (0.92 +/- 0.14 vs. 0.69 +/- 0.09 cGy), and GN (0.20 +/- 0.00 vs. 0.22 +/- 0.01cGy). Fluoroscopy times and measured surface entrance doses of ionizing radiation in patients undergoing Amplatzer device occlusion are similar to those in patients undergoing routine diagnostic catheterization.

Radiation exposure to children during coil occlusion of the patent ductus arteriosus

The risks of excessive exposure to ionizing radiation are well described and measures are routinely taken to limit such exposure to both patient and personnel in the catheterization laboratory. Coll occlusion of the patent ductus arteriosus (PDA) as well as other more complex pediatric interventions has raised concern regarding radiation exposure, particularly as minimally invasive surgical techniques are being developed which lack such exposure risk. In eight consecutive patients, aged 0.7-7 years (median, 2.3 years), coil occlusion of a PDA was performed and surface entrance radiation dose determined by thermoluminescent dosimetry (TD). Total cumulative doses (PA + lateral dose) were also calculated for each patient. Entrance and cumulative dose was likewise measured in 12 patients undergoing standard diagnostic catheterization (DC) and in 5 consecutive patients undergoing pulmonary balloon valvuloplasty (PBV). The groups were comparable in age, weight, and body surface area (BSA). Total cumulative dose in the PDA patients was 97 +/- 25 mGy (mean +/- SE). There was no significant difference between the three groups in entrance dose absorbed at each location or in total cumulative dose. The mean total fluoroscopy time in the PDA occlusion group was significantly less than that of the PBV group (10.1 +/- 1.81 min vs. 19.3 +/- 2.29 min, P < 0.05) but was comparable to the DC group (13.2 +/- 1.5 min, P = NS). When the subjects were analyzed collectively, no correlation between fluoroscopy time and measured entrance dose was observed. The strongest correlates of total cumulative dose were patient weight (r = 0.67, P < 0.001) and BSA (r = 0.62, P = 0.001). Patients undergoing coil occlusion of a PDA are not exposed to increased radiation entrance dose compared to those undergoing standard DC and PBV. Furthermore, surface entrance radiation dose as determined by TD varies according to patient size for a given fluoroscopy time.

Transhepatic therapeutic cardiac catheterization: a new option for the pediatric interventionalist

We evaluate the efficacy and safety of percutaneous transhepatic (TH) venous access for interventional cardiac catheterization. A retrospective review of all TH therapeutic catheterizations between January 1994 and September 1998 was performed. Patient demographics, pre- and postcatheterization hemoglobin and liver function studies, and complications were evaluated. TH access was performed for 30 interventional catheterizations in 25 patients with a median age of 39 months (range, 1 day to 41 years) and weight of 13.2 kg (3.1-87.0 kg). Indications for TH access were bilateral obstructed femoral veins (n = 15), obstructed femoral veins and superior vena cava (n = 3), Greenfield filter (n = 2), and presumptive improved route for intervention via TH access (n = 5). TH interventions were successful in 29/30 procedures (97%). Interventions via TH sheath sizes of 4-14 Fr included pulmonary angioplasty +/- stent (n = 11), radiofrequency ablation (n = 4), atrial septal defect device occlusion (n = 2), coil occlusion of pulmonary artery pseduoaneurysm (n = 2), Fontan fenestration device occlusion (n = 2), pulmonary valvuloplasty (n = 2), stent dilation of the superior vena cava (n = 2), and one each of device retrieval, Fontan baffle stent placement and subsequent redilation, Fontan fenestration dilation, transseptal mitral valvuloplasty, and cardiac biopsy. There were no changes in pre- and post-TH hemoglobin levels (mean +/- SD, 12.9+/-2.2 vs. 11.9+/-1.9 gm/dL; P = NS) or alanine transferase (34.0+/-27.5 vs. 43.4+/-18.2 IU/L; P = NS). One patient developed important intraperitoneal bleeding and required exploratory laporatomy. Percutaneous TH access is safe and effective as a route for interventional catheter procedures for patients with limited venous access.

Transhepatic therapeutic cardiac catheterization: a new option for the pediatric interventionalist

We evaluate the efficacy and safety of percutaneous transhepatic (TH) venous access for interventional cardiac catheterization. A retrospective review of all TH therapeutic catheterizations between January 1994 and September 1998 was performed. Patient demographics, pre- and postcatheterization hemoglobin and liver function studies, and complications were evaluated. TH access was performed for 30 interventional catheterizations in 25 patients with a median age of 39 months (range, 1 day to 41 years) and weight of 13.2 kg (3.1-87.0 kg). Indications for TH access were bilateral obstructed femoral veins (n = 15), obstructed femoral veins and superior vena cava (n = 3), Greenfield filter (n = 2), and presumptive improved route for intervention via TH access (n = 5). TH interventions were successful in 29/30 procedures (97%). Interventions via TH sheath sizes of 4-14 Fr included pulmonary angioplasty +/- stent (n = 11), radiofrequency ablation (n = 4), atrial septal defect device occlusion (n = 2), coil occlusion of pulmonary artery pseduoaneurysm (n = 2), Fontan fenestration device occlusion (n = 2), pulmonary valvuloplasty (n = 2), stent dilation of the superior vena cava (n = 2), and one each of device retrieval, Fontan baffle stent placement and subsequent redilation, Fontan fenestration dilation, transseptal mitral valvuloplasty, and cardiac biopsy. There were no changes in pre- and post-TH hemoglobin levels (mean +/- SD, 12.9+/-2.2 vs. 11.9+/-1.9 gm/dL; P = NS) or alanine transferase (34.0+/-27.5 vs. 43.4+/-18.2 IU/L; P = NS). One patient developed important intraperitoneal bleeding and required exploratory laporatomy. Percutaneous TH access is safe and effective as a route for interventional catheter procedures for patients with limited venous access.

Neonatal cardiac catheterization: A 10-year transition from diagnosis to therapy

To assess the changing role of cardiac catheterization in the care of the neonate, a retrospective review of all catheterizations between January 1984 to December 1985 (group I) and January 1994 to December 1995 (group II) at C.S. Mott Children's Hospital was performed. Neonatal cardiac catheterization was performed more frequently (p = 0.02) in group I, comprising 14% (110 of 772) of all catheterizations versus 11% (93 of 880) in group II. Access was performed by cutdown in 15 patients (13 venous and 2 arterial), all in group I. In group I, 20 of 110 patients (18%) had balloon atrial septostomies; no other catheter interventions were performed. Interventions were more frequent (p = 0.003) and varied in group II, including 15 septostomies, 17 balloon valvuloplasties (13 pulmonary and 4 aortic), 2 coil embolizations of collaterals, and 1 cardiac biopsy. Despite the higher prevalence and complexity of interventions in group II, fluoroscopy times (median; range: 16 min; 2-55 vs 16 min; 1-107) were similar in both groups (p = not significant) as well as the prevalence of complications. Neonatal cardiac catheterizations are performed less frequently than they were a decade ago at our institution, and therapeutic interventions have become more common. Despite these changes, fluoroscopy time and the rate of complications have not increased.

Validation of color Doppler measurements of minimum patent ductus arteriosus diameters: significance for coil embolization

BACKGROUND

Echocardiography is sometimes performed to identify candidates for coil embolization of patent ductus arteriosus (PDA). Therefore we attempted to determine the validity of color Doppler echocardiography to accurately determine the minimum PDA diameter.

METHODS AND RESULTS

We reviewed data from 27 children (median 3.8 years, range 1 to 15 years) with PDAs and measured their minimum ductal diameters by color flow Doppler echocardiography and by angiography. We found that there were significant mean differences between the color Doppler and angiographic measurements (2.7+/-0.8 vs 1.6+/-0.7 mm, P< .001) with color Doppler exceeding angiographic measurements by > or = 1.0 mm in 15 (56%) of 27 patients. More importantly, color Doppler measured a PDA > or = 4.0 mm (usually greater than that recommended for coiling) in 3 (11%) patients in whom the angiographic measurement was <4.0 mm. Correlation analysis demonstrated no correlation between the color Doppler and angiographic measurements (r2 = 0.17, P= .04, SEE = 0.2 mm).

CONCLUSIONS

These data suggest that color Doppler echocardiography often overestimates the true minimum PDA diameter, therefore we recommend that a color Doppler-based recommendation that a PDA is too large for transcatheter coil occlusion not be used exclusively to exclude a patient from this treatment modality.

Late fenestration closure in the hypoplastic left heart syndrome: comparison of hemodynamic changes

BACKGROUND AND OBJECTIVES

Although survival of patients with the hypoplastic left heart syndrome treated by staged surgical palliation has improved, hemodynamic data after fenestrated Fontan operation and after fenestration closure have not been reported in this patient population. We sought to describe the hemodynamic status of these patients at cardiac catheterization performed for the purpose of fenestration closure and to compare these data with data from contemporary patients with other forms of univentricular heart.

METHODS AND RESULTS

Hemodynamic responses to fenestration closure during cardiac catheterization were reviewed in 40 consecutive patients, including 20 with the hypoplastic left heart syndrome and 20 with other forms of univentricular heart defects. Hemodynamics before fenestration closure (arterial saturation and pressure, Fontan baffle saturation and pressure, pulmonary capillary wedge pressure, systemic arteriovenous oxygen content difference, and right-to-left shunt fraction) were nearly identical between the two groups. Significant (p < 0.05) changes after fenestration closure included increases in arterial saturation (9%), mean arterial pressure (3 mm Hg), and baffle pressure (1 mm Hg) and arteriovenous oxygen content difference (18 ml/L), with near elimination of right-to-left shunting. Cardiac output decreased by 21% and systemic oxygen transport by 13%, with no differences between the two patient groups. Mean baffle pressures were <17 mm Hg in 32 patients (80%).

CONCLUSIONS

Hemodynamics after fenestrated Fontan operation and responses to fenestration closure in patients with the hypoplastic left heart syndrome were remarkably similar to that in patients with other univentricular heart defects.

Intraperitoneal hemorrhage associated with transhepatic cardiac catheterization: a report of two cases

Transhepatic cardiac catheterization has gained increased interest as a novel technique for venous vascular access with few complications. We report important intra-abdominal bleeding encountered in two patients during transhepatic cardiac catheterization. We describe their management and suggest possible nonoperative strategies.

Intraperitoneal hemorrhage associated with transhepatic cardiac catheterization: a report of two cases

Transhepatic cardiac catheterization has gained increased interest as a novel technique for venous vascular access with few complications. We report important intra-abdominal bleeding encountered in two patients during transhepatic cardiac catheterization. We describe their management and suggest possible nonoperative strategies.

Coarctation of the aorta following coil occlusion of a patent ductus arteriosus

A case is described in which coarctation of the aorta develops following coil occlusion of a patent ductus arteriosus with a single Gianturco coil. This finding has yet to be reported in children undergoing this procedure and demonstrates the possibility of its occurrence and brings into question the need for and the duration of antibiotic prophylaxis following coil deployment.

Usefulness of repeat balloon aortic valvuloplasty in children

This retrospective study examines all 15 patients who underwent a second balloon dilation procedure for congenital aortic stenosis to determine its safety and efficacy. The recurrent gradient was significantly reduced, but 4 patients had unsatisfactory gradient relief, 3 of whom had previous surgical valvotomies; therefore, we conclude that repeat balloon aortic valvuloplasty is worthwhile, although third balloon dilations may not be beneficial.

Comparison of hospital charges for balloon angioplasty and surgical repair in children with native coarctation of the aorta

A retrospective review of hospital charges was performed in children > 1 year old with native coarctation of the aorta who underwent balloon angioplasty, primary surgical repair, or elective surgical repair after unsuccessful balloon angioplasty. Hospital charges were less overall in the balloon angioplasty group, although the failure rate was higher.

Pulmonary artery size and flow disturbances after patent ductus arteriosus coil occlusion

Transcatheter closure of patent ductus arteriosus with Gianturco coils may impinge on adjacent vascular structures. The left pulmonary artery relative size may decrease after patent ductus arteriosus coil occlusion; thus, serial follow-up echocardiography is recommended to assess long-term left pulmonary artery growth.

Hemolysis following coil embolization of a patent ductus arteriosus

We describe the development of hemolysis from moderate residual shunting across a patent ductus arteriosus following coil embolization. The fall in hemoglobin levels from 11.6 to 6.0 gm/dl necessitated a second coil procedure which resulted in complete closure of the residual shunting and resolution of hemolysis. Therefore, appearance of anemia following coil embolization of patent ductus arteriosus should be monitored closely; however, repeat coil embolization with elimination of residual shunt will lead to prompt recovery of normal hemoglobin levels.

Percutaneous transhepatic mitral commissurotomy

A novel, transhepatic approach to mitral valvuloplasty is described in a patient with an inferior vena caval filter. After transhepatic transseptal puncture, an Inoue dilatation catheter was passed through the hepatic parenchyma and across the atrial septum. Balloon mitral valvuloplasty was performed without complications. This approach should be considered when femoral venous access is restricted or is not feasible.

Follow-up of coil occlusion of patent ductus arteriosus

OBJECTIVE

We sought to determine the prevalence and fate of residual ductal shunting following coil occlusion of patent ductus arteriosus.

BACKGROUND

Although transcatheter coil occlusion of patent ductus arteriosus has gained popularity, few follow-up data have been reported.

METHODS

A review of 75 patients who underwent coil occlusion was performed. Residual shunting was investigated by Doppler echocardiography in follow-up. Angiograms were reviewed to obtain minimal ductal diameter and ductal angiographic type.

RESULTS

Residual shunts were found in 31 patients (41%) on the day of the procedure, and of these, spontaneous closure was noted in 17 (55%) at 2 weeks to 20 months of follow-up. Of the 75 patients studied, 5 (7%) required a second coil procedure, and 10 (13%) remained with persistent residual shunts at most recent follow-up. Actuarial analysis estimated a 6 +/- 5% prevalence of residual shunts 20 months after a single coil procedure and 3 +/- 3% after all coil procedures. Minimal ductal diameter was associated with immediate complete ductal occlusion by a single coil. These patients had significantly smaller (p = 0.003) minimal ductal diameters (1.2 +/- 0.7 mm) than those who required two coils during their initial procedure to achieve immediate occlusion (1.9 +/- 0.7 mm), those who required a second coil procedure (2.0 +/- 0.9 mm), those who had spontaneous closure of residual shunts (1.9 +/- 0.7 mm) and those with persistent residual shunts (2.0 +/- 0.9 mm). No association was identified between ductal angiographic type and outcome of coil occlusion. No late adverse clinical events of coil occlusion or evidence of recanalization was found.

CONCLUSIONS

Small residual shunts are common after coil embolization of patent ductus arteriosus, but most close spontaneously. Actuarial analysis estimates complete closure in 94% at 20 months, and reintervention was required in only 7% of patients.

Embolization therapy in pediatric cardiology

Transcatheter embolization therapy has assumed an important role in the management of patients with congenital heart disease. A variety of embolization materials, most commonly steel coils, is available to treat or palliate patients with aortopulmonary collateral vessels or surgical shunts, arteriovenous malformations, and anomalous venovenous connections (common after surgical intervention for the univentricular heart). At many centers, coil occlusion has recently become the treatment of choice for patients with a restrictive patent ductus arteriosus (PDA). This article describes the materials and techniques of embolization therapy, as well as the common indications encountered in the practice of pediatric interventional cardiology.

Transhepatic cardiac catheterization in children. Evaluation of efficacy and safety

BACKGROUND

In some children with congenital heart disease, conventional venous access is unavailable for cardiac catheterization. This study investigates a novel transhepatic venous approach to cardiac catheterization in children and evaluates its efficacy and safety.

METHODS AND RESULTS

Percutaneous transhepatic puncture was performed using a 22-gauge Chiba needle under fluoroscopic guidance. After wire exchanges were performed, a 5F to 8F sheath was positioned in the low right atrium and cardiac catheterization was performed. On completion of the catheterization, the sheath was withdrawn and a 3-mm steel coil was placed in the parenchymal tract between the hepatic vein and liver capsule. Liver enzyme studies were obtained before and after transhepatic catheterization, and an abdominal ultrasound was performed to evaluate the liver 24 hours after the procedure. Percutaneous transhepatic cardiac catheterization was performed successfully in 17 of 18 children in whom it was attempted. Patient age was 30 +/- 8 months (mean +/- SEM; range, 1 day to 9 years), weight was 10.5 +/- 1.5 kg (3.1 to 27.5 kg), and mean right atrial pressure was 10 +/- 1 mm Hg (5 to 19 mm Hg). Time from initial needle puncture to right atrial entry was 6.2 +/- 1.2 minutes. Diagnostic catheterization was performed successfully in all 17 children, and additional interventional procedures were performed in 5 children. The total catheterization time was 2.0 +/- 0.2 hours. Serum aspartate aminotransferase increased from 57 +/- 15 to 78 +/- 8 IU/L (P = .06), but alanine aminotransferase and gamma-glutamyl transpeptidase did not change. Ultrasound was performed 24 hours after transhepatic catheterization, and no evidence was found in any patient of hemorrhage or subcapsular hematoma.

CONCLUSIONS

These data suggest that this novel transhepatic approach provides an effective and safe route for diagnostic and interventional cardiac catheterization in children.