Extracardiac Fontan with T-shape conduit in non-confluent pulmonary arteries

A 34 months-old male patient with double inlet right ventricle with nonconfluent pulmonary arteries who underwent successful extracardiac fenestarated Fontan procedure using pre-designed T-shaped PTFE vascular graft after multi-step rehabilitation of the diminutive hilar pulmonary arteries. At first we performed 6 mm confluent pulmonary artery vascular graft implantation with 4 mm BT shunt at patient's 4 weeks old. At 9 months of patient, we upsized the confluent pulmonary arterial graft to 8 mm with bidirectional cavopulmonary connection, and, at 34 months, we performed extracardiac conduit Fontan procedure with pre-designed T-shape conduit including the confluent pulmonary arterial portion at last. Patient shows excellent functional status and development

Enhancing Hematopoietic Stem Cell Transplantation Efficacy by Mitigating Oxygen Shock

Hematopoietic stem cells (HSCs) reside in hypoxic niches within bone marrow and cord blood. Yet, essentially all HSC studies have been performed with cells isolated and processed in non-physiologic ambient air. By collecting and manipulating bone marrow and cord blood in native conditions of hypoxia, we demonstrate that brief exposure to ambient oxygen decreases recovery of long-term repopulating HSCs and increases progenitor cells, a phenomenon we term extraphysiologic oxygen shock/stress (EPHOSS). Thus, true numbers of HSCs in the bone marrow and cord blood are routinely underestimated. We linked ROS production and induction of the mitochondrial permeability transition pore (MPTP) via cyclophilin D and p53 as mechanisms of EPHOSS. The MPTP inhibitor cyclosporin A protects mouse bone marrow and human cord blood HSCs from EPHOSS during collection in air, resulting in increased recovery of transplantable HSCs. Mitigating EPHOSS during cell collection and processing by pharmacological means may be clinically advantageous for transplantation

Clinical Significance of Thrombosis in an Intracardiac Blind Pouch After a Fontan Operation

The univentricular heart after the Fontan operation may have a blind pouch formed by the pulmonary stump or rudimentary ventricle according to the anatomy before surgery. Thrombosis in an intracardiac blind pouch of patients with a univentricular heart is a hazardous complication. Because only a few reports have described this complication, the authors evaluated the clinical significance of thrombosis in an intracardiac blind pouch of a univentricular heart. They performed a retrospective review of medical records from August 1986 to December 2007. Four patients were confirmed as having thrombosis in a pulmonary artery stump and one patient as having thrombosis in a rudimentary ventricle shown by cardiac computed tomography (CT). This represents 1.85% (5/271) of patients with ongoing regular follow-up evaluation after the Fontan operation. The median age at diagnosis was 14.2 years. Two of the five patients were taking aspirin and one patient was taking warfarin when they were identified for the development of thrombosis. None of the patients demonstrated thrombosis in the Fontan tract or venous side of the circulation. Brain magnetic resonance imaging (MRI) showed that three patients had cerebral infarction and one patient had suggestive old ischemia. Three patients with thrombus in the pulmonary stump underwent pulmonary artery stump thrombectomy and pulmonary valve obliteration. One patient with thrombus in the rudimentary ventricle underwent ventricular septal defect (VSD) closure with thrombectomy. Thrombus in a blind pouch could cause systemic thromboembolism despite little blood communication. Therefore, surgical modification of the pulmonary stump and VSD closure of the rudimentary ventricle are required to reduce the risk of later thrombus formation. Clinicians should not overlook the possibility of thrombus in a ligated pulmonary artery stump or a rudimentary ventricle after the Fontan operation, which may increase the risk of embolic stroke for patients with single-ventricle physiology

Zebrafish Kidney Phagocytes Utilize Macropinocytosis and Ca2+-Dependent Endocytic Mechanisms

Background: The innate immune response constitutes the first line of defense against invading pathogens and consists of a variety of immune defense mechanisms including active endocytosis by macrophages and granulocytes. Endocytosis can be used as a reliable measure of selective and non-selective mechanisms of antigen uptake in the early phase of an immune response. Numerous assays have been developed to measure this response in a variety of mammalian and fish species. The small size of the zebrafish has prevented the large-scale collection of monocytes/macrophages and granulocytes for these endocytic assays. Methodology/Principal Findings: Pooled zebrafish kidney hematopoietic tissues were used as a source of phagocytic cells for flow-cytometry based endocytic assays. FITC-Dextran, Lucifer Yellow and FITC-Edwardsiella ictaluri were used to evaluate selective and non-selective mechanisms of uptake in zebrafish phagocytes. Conclusions/Significance: Zebrafish kidney phagocytes characterized as monocytes/macrophages, neutrophils and lymphocytes utilize macropinocytosis and Ca 2+-dependant endocytosis mechanisms of antigen uptake. These cells do not appear to utilize a mannose receptor. Heat-killed Edwardsiella ictaluri induces cytoskeletal interactions for internalization in zebrafish kidney monocytes/macrophages and granulocytes. The proposed method is easy to implement and should prove especially useful in immunological, toxicological and epidemiological research

Antileishmanial High-Throughput Drug Screening Reveals Drug Candidates with New Scaffolds

Drugs currently available for leishmaniasis treatment often show parasite resistance, highly toxic side effects and prohibitive costs commonly incompatible with patients from the tropical endemic countries. In this sense, there is an urgent need for new drugs as a treatment solution for this neglected disease. Here we show the development and implementation of an automated high-throughput viability screening assay for the discovery of new drugs against Leishmania. Assay validation was done with Leishmania promastigote forms, including the screening of 4,000 compounds with known pharmacological properties. In an attempt to find new compounds with leishmanicidal properties, 26,500 structurally diverse chemical compounds were screened. A cut-off of 70% growth inhibition in the primary screening led to the identification of 567 active compounds. Cellular toxicity and selectivity were responsible for the exclusion of 78% of the pre-selected compounds. The activity of the remaining 124 compounds was confirmed against the intramacrophagic amastigote form of the parasite. In vitro microsomal stability and cytochrome P450 (CYP) inhibition of the two most active compounds from this screening effort were assessed to obtain preliminary information on their metabolism in the host. The HTS approach employed here resulted in the discovery of two new antileishmanial compounds, bringing promising candidates to the leishmaniasis drug discovery pipeline

Broad spectrum late blight resistance in potato differential set plants MaR8 and MaR9 is conferred by multiple stacked R genes

Phytophthora infestans is the causal agent of late blight in potato. The Mexican species Solanum demissum is well known as a good resistance source. Among the 11 R gene differentials, which were introgressed from S. demissum, especially R8 and R9 differentials showed broad spectrum resistance both under laboratory and under field conditions. In order to gather more information about the resistance of the R8 and R9 differentials, F1 and BC1 populations were made by crossing Mastenbroek (Ma) R8 and R9 clones to susceptible plants. Parents and offspring plants were examined for their pathogen recognition specificities using agroinfiltration with known Avr genes, detached leaf assays (DLA) with selected isolates, and gene-specific markers. An important observation was the discrepancy between DLA and field trial results for Pi isolate IPO-C in all F1 and BC1 populations, so therefore also field trial results were included in our characterization. It was shown that in MaR8 and MaR9, respectively, at least four (R3a, R3b, R4, and R8) and seven (R1, Rpi-abpt1, R3a, R3b, R4, R8, R9) R genes were present. Analysis of MaR8 and MaR9 offspring plants, that contained different combinations of multiple resistance genes, showed that R gene stacking contributed to the Pi recognition spectrum. Also, using a Pi virulence monitoring system in the field, it was shown that stacking of multiple R genes strongly delayed the onset of late blight symptoms. The contribution of R8 to this delay was remarkable since a plant that contained only the R8 resistance gene still conferred a delay similar to plants with multiple resistance genes, like, e.g., cv Sarpo Mira. Using this “de-stacking” approach, many R gene combinations can be made and tested in order to select broad spectrum R gene stacks that potentially provide enhanced durability for future application in new late blight resistant varieties

Screening ethnically diverse human embryonic stem cells identifies a chromosome 20 minimal amplicon conferring growth advantage

The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups. Most lines remained karyotypically normal, but there was a progressive tendency to acquire changes on prolonged culture, commonly affecting chromosomes 1, 12, 17 and 20. DNA methylation patterns changed haphazardly with no link to time in culture. Structural variants, determined from the SNP arrays, also appeared sporadically. No common variants related to culture were observed on chromosomes 1, 12 and 17, but a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells