Coronary myocardial bridge: an innocent bystander?

Myocardial bridge (MB) or tunneled coronary artery is an inborn abnormality, which implicates a systolic vessel compression with a persistent mid-late diastolic diameter reduction. Myocardial bridges are often observed during coronary angiography with an incidence of 0.5%-5.5%. The most involved coronary artery is the left anterior descending artery followed by the diagonal branches, the right coronary artery, and the left circumflex. The overall long-term prognosis is generally benign. However, several risk or precipitating factors (e.g., high heart rate, left ventricular hypertrophy, decreased peripheral vascular resistance) may trigger symptoms (most frequently angina). Herein, we describe two cases of symptomatic myocardial bridge, where medical treatment (i.e., inotropic negative drug) and coronary stenting were successfully utilized to treat this pathology. We also focus on the clinical presentation, and the diagnostic and therapeutic modalities to correctly manage this frequently observed congenital coronary abnormality, underlining the fact that in cases of typical angina symptoms without any significant coronary artery disease, MB should be considered as a possible differential diagnosi

Green Edge ice camp campaigns : understanding the processes controlling the under-ice Arctic phytoplankton spring bloom

The Green Edge initiative was developed to investigate the processes controlling the primary productivity and fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiqtarjuaq Island in Baffin Bay (67.4797∘ N, 63.7895∘ W). During both expeditions, a large suite of physical, chemical and biological variables was measured beneath a consolidated sea-ice cover from the surface to the bottom (at 360 m depth) to better understand the factors driving the PSB. Key variables, such as conservative temperature, absolute salinity, radiance, irradiance, nutrient concentrations, chlorophyll a concentration, bacteria, phytoplankton and zooplankton abundance and taxonomy, and carbon stocks and fluxes were routinely measured at the ice camp. Meteorological and snow-relevant variables were also monitored. Here, we present the results of a joint effort to tidy and standardize the collected datasets, which will facilitate their reuse in other Arctic studies

PTPA variants and impaired PP2A activity in early-onset parkinsonism with intellectual disability

The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alpha-synuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T&gt;G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C&gt;A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.</p

Marshall, Donald. Ra'ivavae. An expedition to the most fascinating and mysterious island in Polynesia

Vérin Pierre. Marshall, Donald. Ra'ivavae. An expedition to the most fascinating and mysterious island in Polynesia. In: Journal de la Société des océanistes, tome 17, 1961. pp. 71-72

L'étude des langues créoles de la Jamaïque

Vérin Pierre. L'étude des langues créoles de la Jamaïque. In: Journal de la Société des Américanistes. Tome 48, 1959. pp. 254-255