Insights on Atrial Fibrillation in Congenital Heart Disease

Patients with congenital heart disease (CHD) have been surviving late into adulthood, with atrial arrhythmias being the most common long-term complication. In recent reports, atrial fibrillation (AF) tended to be the most common form of arrhythmias among groups of patients with adult CHD (ACHD) older than 50 years of age. When compared with their adult counterparts without CHD, AF in patients with ACHD has been characterized by a higher incidence and prevalence, younger age of onset, and a greater risk of progression to persistent AF. Risk factors for the development of AF are not well known but include older age, left atrial dilation, systemic hypertension, and multiple cardiac surgeries. Data on management options such as optimal antiarrhythmic drug therapy, indications for anticoagulation, and efficacy and safety of catheter ablation are limited. There is a crucial need for further research exploring management, prevention, and monitoring strategies for the growing ACHD patient population with AF. This report will provide a contemporary review of the epidemiology, pathophysiology, and management options for AF in this complex patient population.     

Recipient and donor cells in the graft-versus-solid tumor effect: It takes two to tango

Allogeneic hematopoietic stem cell transplantation (alloHSCT) produces –similar to the long-established graft-versus-leukemia effect– graft-versus-solid-tumor effects. Clinical trials reported response rates of up to 53%, occurring mostly but not invariably in association with full donor chimerism and/or graft-versus-host disease. Although donor-derived T cells are considered the principal effectors of anti-tumor immunity after alloHSCT or donor leukocyte infusion (DLI), growing evidence indicate that recipient-derived immune cells may also contribute. Whereas the role of recipient-derived antigen-presenting cells in eliciting graft-versus-host reactions and priming donor T cells following DLI is well known, resulting inflammatory responses may also break tolerance of recipient effector cells towards the tumor. Additionally, mouse studies indicated that post-transplant recipient leukocyte infusion produces anti-leukemia and anti-solid-tumor effects that were exclusively mediated by recipient-type effector cells, without graft-versus-host disease. Here, we review current preclinical and clinical evidence on graft-versus-solid-tumor effects and growing evidence on the effector role of recipient-derived immune cells in the anti-tumor effect of alloHSCT.     

Geographical Patterns in Cyanobacteria Distribution: Climate Influence at Regional Scale

Cyanobacteria are a component of public health hazards in freshwater environments because of their potential as toxin producers. Eutrophication has long been considered the main cause of cyanobacteria outbreak and proliferation, whereas many studies emphasized the effect of abiotic parameters (mainly temperature and light) on cell growth rate or toxin production. In view of the growing concerns of global change consequences on public health parameters, this study attempts to enlighten climate influence on cyanobacteria at regional scale in Brittany (NW France). The results show that homogeneous cyanobacteria groups are associated with climatic domains related to temperature, global radiation and pluviometry, whereas microcystins (MCs) occurrences are only correlated to local cyanobacteria species composition. As the regional climatic gradient amplitude is similar to the projected climate evolution on a 30-year timespan, a comparison between the present NW and SE situations was used to extrapolate the evolution of geographical cyanobacteria distribution in Brittany. Cyanobacteria composition should shift toward species associated with more frequent Microcystins occurrences along a NW/SE axis whereas lakes situated along a SW/NE axis should transition to species (mainly Nostocales) associated with lower MCs detection frequencies.     

In vivo 1H MRS study in microlitre voxels in the hippocampus of a mouse model of Down syndrome at 11.7 T

In this article, we report in vivo ¹H MRS performed in 1.8‐μL voxels in a mouse model of Down syndrome (DS). To characterise the excitation–inhibition imbalance observed in DS, metabolite concentrations in the hippocampi of adult Ts65Dn mice, which recapitulate features of DS, were compared with those of their euploid littermates at a voxel 42‐fold smaller than in a previously published study. Quantification of the metabolites was performed using a linear combination model. We detected 16 metabolites in the right and left hippocampi. Principal component analysis revealed that the absolute concentrations of the 16 detected metabolites could differentiate between Ts65Dn and euploid hippocampi. Although measurements in the left and right hippocampi were highly correlated, the concentration of individual metabolites was sometimes significantly different in the left and right structures. Thus, bilateral values from Ts65Dn and euploid mice were further compared with Hotelling's test. The level of glutamine was found to be significantly lower, whereas myo‐inositol was significantly higher, in the hippocampi of Ts65Dn relative to euploid mice. However, γ‐aminobutyric acid (GABA) and glutamate levels remained similar between the groups. Thus, the excitation–inhibition imbalance described in DS does not appear to be related to a radical change in the levels of either GABA or glutamate in the hippocampus. In conclusion, microliter MRS appears to be a valuable tool to detect changes associated with DS, which may be useful in investigating whether differences can be rescued after pharmacological treatments or supplementation with glutamine. Copyright © 2014 John Wiley & Sons, Ltd.