Biology subjects

Serrano, R.

Publications and source records attributed to Serrano, R..

2 recordsLinked to original sources

bioRxiv2019

Drug related and psychopathological symptoms in HIV-positive men who have sex with men who inject drugs during sex (Slamsex): Data from the U-SEX GESIDA 9416 Study.

ObjectivesIntravenous sexualized drug use also known as slamsex seems to be increasing among HIV-positive men who have sex with men (MSM). This practice may entail severe consequences for physical and mental health in this population. Research on the subject is scarce. The aim of our study was to describe the psychopathological background of a sample of HIV positive MSM who practiced slamsex during the previous year and compare the physical and psychological symptoms between these participants and those who practiced sexualized drug use (SDU) or chemsex without slamsex.\n\nDesign and MethodsParticipants (HIV-positive MSM) were recruited from the U-Sex study in 22 HIV clinics in Madrid during 2016-17. All participants completed an anonymous cross-sectional survey on sexual behaviour and recreational drug use. The present analysis is based on HIV-positive MSM who had practiced SDU.\n\nResultsThe survey sample comprised 742 participants. Of all the participants who completed the survey, 216 (29.1%) practiced chemsex, and of these, 34 (15.7%) had practiced slamsex. Participants who practiced slamsex were more likely to have current psychopathology (depression, anxiety and drug related disorders) than chemsex users. In addition, participants who practiced slamsex had more high-risk sexual behaviours, polydrug use and were more often diagnosed with sexually transmitted infections (STIs) and hepatitis C than those who did not inject drugs. Compared with patients who did not inject drugs, patients who engaged in slamsex showed more severe drug related symptoms (withdrawal and dependence), symptoms of severe intoxication (loss of consciousness), and severe psychopathological symptoms related to SDU, such as paranoid thoughts and suicidal behaviour.\n\nConclusionSlamsex (intravenous SDU) is closely associated with current psychiatric disorders and severe drug-related and psychiatric symptoms.

scientific communication and education↗

bioRxiv2019

Three-dimensional Monolayer Stress Microscopy

Many biological processes involve the collective generation and transmission of mechanical stresses across cell monolayers. In these processes, the monolayer undergoes lateral deformation and bending due to the tangential and normal components of the cell-generated stresses. Monolayer Stress Microscopy (MSM) methods have been developed to measure the intracellular stress distribution in cell monolayers. However, current methods assume plane monolayer geometry and neglect the contribution of bending to the intracellular stresses.\n\nThis work introduces a three-dimensional (3D) MSM method that calculates monolayer stress from measurements of the 3D traction stresses exerted by the cells on a flexible substrate. The calculation is carried out by imposing equilibrium of forces and moments in the monolayer, subject to external loads given by the 3D traction stresses. The equilibrium equations are solved numerically, and the algorithm is validated for synthetic loads with known analytical solutions.\n\nWe present 3D-MSM measurements of monolayer stress in micropatterned islands of endothelial cells of different sizes and shapes. These data indicate that intracellular stresses caused by lateral deformation emerge collectively over long distances; they increase with the distance from the island edge until they reach a constant value that is independent of island size. On the other hand, bending-induced intracellular stresses are more concentrated spatially and remain confined to within 1-2 cell lengths of bending sites. The magnitude of these bending stresses is highest at the edges of the cell islands, where they can exceed the intracellular stresses caused by lateral deformations. Our data from non-patterned monolayers suggests that biomechanical perturbations far away from monolayer edges also cause significant localized alterations in bending tension. The localized effect of bending-induced stresses may be important in processes like cellular extravasation, which are accompanied by significant normal deflections of a cell monolayer (i.e. the endothelium), and which require localized changes in monolayer permeability.

biophysics↗