A Locus for Autosomal Recessive Pseudoxanthoma Elasticum, with Penetrance of Vascular Symptoms in Carriers, Maps to Chromosome 16p13.1

Pseudoxanthoma elasticum (PXE) is a heritable systemic disorder characterized by calcification of the elastic fibers of the connective tissue. Symptoms are predominantly noted in the eye, the skin, and the cardiovascular system, resulting in visual loss, skin lesions, and life-threatening vascular disease. In this study we combined homozygosity mapping and genome scanning with 374 markers in affected individuals from a PXE family from a genetically isolated population in The Netherlands. Initial homozygosity in two or three patients was found with up to 20 markers, among which D16S292 located in 16p13.1. Upon refined and more extensive family screening of the latter region, close linkage without recombination was found with the marker D16S764 (Z_max=6.27). Despite clear autosomal recessive inheritance of the ocular symptoms in PXE, vascular symptoms appear in 40%–50% of the heterozygotes.     

An automatic method for determining the centre of rotation of a mechanically scanned reflection UCT system

A method will be described for determining the centre of rotation of a mechanically scanned reflection ultrasound computed tomography system. It is based on the principle of obtaining opposing images of a test object containing many point targets. The method is automatic in the sense that the centre of rotation is calculated by a computer without the need for an operator to make direct measurements on the mechanical system. For the particular reflection UCT system described here, the centre of rotation is obtained in 3-5 min with a repeatability (+/-2 SD) of +/-0.3 mm. Ways in which even higher accuracy can be obtained are discussed. The basic principle of the method is applicable to any concentric imaging system for which a good approximation to an ideal point target can be produced.     

Molecular characterization of African swine fever virus from outbreaks in Namibia in 2018

Five samples were collected from four suspected outbreaks of African swine fever in Namibia in 2018. Sequencing of the C‐terminus of the B646L gene (p72 protein), the central hypervariable region (CVR) of the B602L gene, the E183L gene (p54 protein) and the CD2v (used to determine the serogroup) was performed on DNA isolated from the samples. Phylogenetic analyses of the B646L (p72) revealed that one of the samples belonged to genotype I while the remaining samples could not be assigned to any currently known genotype. In contrast, by using the E183L gene three of the samples were shown to belong to genotype Id and only two were of unknown genotype. Based on the analysis of the partial CD2v amino acid sequences of four of the samples, one of the viruses clustered with serogroup 2 while the other three did not cluster within any of the eight known serogroups. Examination of the CVR identified three variants with 8, 18 and 24 tetrameric tandem repeat sequences. This study indicates that at least three different genetically distinct ASFV are currently present in Namibia.     

Exploring the ethics of genetic prioritisation for COVID-19 vaccines

There is evidence to suggest that host genomic factors may account for disease response variability in COVID-19 infection. In this paper, we consider if and how host genomics should influence decisions about vaccine allocation. Three potential host genetic factors are explored: vulnerability to infection, resistance to infection, and increased infectivity. We argue for the prioritisation of the genetically vulnerable in vaccination schemes, and evaluate the potential for ethical de-prioritisation of individuals with genetic markers for resistance. Lastly, we discuss ethical prioritisation of individuals with genetic markers for increased infectivity (those more likely to spread COVID-19).Subject terms: Health policy, Ethics     

Distance to food stores & adolescent male fruit and vegetable consumption: mediation effects

Background  

The physical environments in which adolescents reside and their access to food stores may influence their consumption of fruit and vegetables. This association could either be direct or mediated via psychosocial variables or home availability of fruit and vegetables. A greater understanding of these associations would aide the design of new interventions. The purpose of this study was to examine associations between distance to food stores and restaurants and fruit and vegetable consumption and the possible mediating role of psychosocial variables and home availability.