MEASUREMENT OF SKIN THICKNESS: A COMPARISON OF TWO IN VIVO TECHNIQUES WITH A CONVENTIONAL HISTOMETRIC METHOD

Two in vivo techniques which are rapid, inexpensive, and reproducible have been investigated. The first is a standardized radiological (xerographic) technique which we have shown is capable of detecting small degrees of dermal atrophy after the application of topical corticosteroid preparations for only one month. The second technique employs the Harpenden Skinfold Caliper used in an unconventional manner so as to exclude subcutaneous fat. We have shown that this too is capable of detecting dermal atrophy from the application of topical corticosteroids and that there is a strong correlation between the two techniques (r = 0.82, p < 0.001). Histometric techniques, on the other hand, give inaccurate and erroneous results for dermal thickness

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

The use of salt dilution gauging techniques: ecological considerations and insights

The salt dilution (gulp injection) technique is a well established and widely used technique to measure stream discharge, flow velocity and water residence characteristics in small headwater streams. However, the impact of the technique on water quality and instream ecology has been largely ignored in field investigations. A series of experiments were undertaken in a regulated and groundwater-dominated river to examine the effects on aquatic invertebrate drift at high, medium and low discharges. In the groundwater-dominated river, drift significantly increased as a result of the introduction of the saline solution under all flows. Drift increased at the regulated site under low and intermediate flow but not during high flows, probably due to a natural increase in drift associated with spate conditions. Following the application of the saline solution several taxa absent or infrequently occurring in background samples, such as the cased caddisfly, Agapetus fuscipes, were recorded. The wider implications of the technique are discussed in relation to short-term pulsed pollution episodes and the management of riverine ecosystems