====== Vasospasm model ======

[[Experimental vasospasm]] [[model]]s are irreplaceable for the [[evaluation]] of new [[antivasospastic drug]]s. Döring et al. from [[Göttingen]] assessed the [[reliability]] of [[in vivo]] [[vasospasm]] [[induction]] by [[ultrasound]] application in the [[chicken chorioallantoic membrane model]] (CAM). After [[incubation]] of fertilized [[chicken]] eggs for four days, a fenestration was performed to enable examination of the CAM vessels. On the thirteenth day, continuous-wave ultrasound (3 MHz, 1 W/cm2) was applied on the CAM vessels for 60 s. The ultrasound effect on the vessels was recorded by life imaging (5-MP HD-microscope camera, [[Leica]]®). The induced vessel diameter changes were evaluated in a defined time interval of 20 min using a Fiji macro. The vessel diameter before and after [[sonication]] was measured and the relative diameter reduction was determined. The first reduction of vessel diameter was observed after three minutes with an average vessel-diameter decrease to 77%. The maximum reduction in vessel diameter was reached eight minutes after sonication with an average vessel diameter decrease to 57% (mean relative diameter reduction of 43%, range 44-61%), ANOVA, p = 0.0002. The vasospasm persisted for all 20 recorded minutes post-induction. Vasospasm can be reliably induced by short application of 3 MHz-ultrasound to the CAM vessels. This might be a suitable in vivo model for the evaluation of drug effects on vasospasm in an experimental setting as an intermediary in the transition process from [[in vitro]] to in vivo assessment using [[animal model]]s
((Döring K, Schroeder H, Fischer A, Sperling S, Ninkovic M, Stadelmann C, Mielke D, Rohde V, Malinova V. [[In Vivo]] [[Vasospasm]] [[Induction]] by [[Ultrasound]] Application in the [[Chicken Chorioallantoic Membrane Model]]. Transl Stroke Res. 2022 Jan 21. doi: 10.1007/s12975-021-00960-y. Epub ahead of print. PMID: 35061211.)).