The forces that arise from the actin cortex play a crucial role in determining the membrane deformation. These include protrusive forces due to actin polymerization, pulling forces due to transient attachment of actin filaments to the membrane, retrograde flow powered by contraction of actomyosin network, and adhesion to the extracellular matrix. Here we present a theoretical model for membrane deformation resulting from the feedback between the membrane shape and the forces acting on the membrane. We model the membrane as a series of beads connected by springs and determine the final steady-state shape of the membrane arising from the interplay between pushing/pulling forces of the actin network and the resisting membrane tension. We specifically investigate the effect of the gel dynamics on the spatio-temporal deformation of the membrane until a stable lamellipodium is formed. We show that the retrograde flow and the cross-linking velocity play an essential role in the final elongation of the membrane. Interestingly, in the simulations where motor-induced contractility is switched off, reduced retrograde flow results in an increase in the rate and amplitude of membrane protrusion. These simulations are consistent with experimental observations that report an enhancement in protrusion efficiency as myosin II molecular motors are inhibited.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6428246 | PMC |
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0213810 | PLOS |
J Neurosurg Case Lessons
January 2025
Department of Neurosurgery, University of California, Irvine, Orange, California.
Background: Intravascular injection of liquid adhesive hemostats is a rare but serious complication that can result in cerebral thromboembolism.
Observations: A 64-year-old female underwent orbitozygomatic craniotomy for posterior communicating artery aneurysm clipping with the routine use of a flowable hemostatic agent during extradural dissection. After placement of the aneurysm clip, flow was confirmed through the parent vessel and nearby branches.
J Thorac Dis
December 2024
College of Chemistry and Life Science, Beijing University of Technology, Beijing, China.
Background: Left ventricular assist device (LVAD) has been widely used as an alternative treatment for heart failure, however, aortic regurgitation is a common complication in patients with LVAD support. And the O-A angle (the angle between LVAD outflow graft and the aorta) is considered as a vital factor associated with the function of aortic valve. To date, the biomechanical effect of the O-A angle on the aortic valve remains largely unknown.
View Article and Find Full Text PDFAnn Pediatr Cardiol
December 2024
Department of Pediatric Cardiology, Star Hospitals, Hyderabad, Telangana, India.
Coronary sinus (CS) defects are rare congenital cardiac anomalies that occur in isolation or with other congenital heart diseases. Persistent left superior vena cava (LSVC) is a relatively common entity that usually drains into the CS, is of no hemodynamic consequence, and is easily diagnosed on echocardiography by a dilated CS and an antegrade flow toward the heart. However, a combination of LSVC and CS defect may reverse its flow direction and CS dilation may be absent.
View Article and Find Full Text PDFIntroduction: Reports of pseudoaneurysms associated with biliary self-expandable metallic stent (SEMS) placement have been increasing. Recently, cases of hepatic pseudoaneurysm rupture caused by double pigtail plastic stents (DPS) have also been reported. The symptoms of pseudoaneurysms are often non-specific, and many cases are diagnosed only after rupture.
View Article and Find Full Text PDFActa Neurochir (Wien)
January 2025
Department of Neurosurgery, The Fourth Affiliated Hospital of Soochow University, Suzhou, China.
Background: Superficial temporal artery (STA)-middle cerebral artery (MCA) side-to-side microvascular anastomosis can achieve the same clinical effects as traditional STA-MCA end-to-side anastomosis in extracranial-intracranial revascularization surgery, furthermore, STA-MCA side-to-side anastomosis has the lower risk of postoperative cerebral hyperperfusion syndrome (CHS) and the potential to recruit all scalp arteries as the donor sources via self-regulation. Therefore, STA-MCA side-to-side microvascular anastomosis seems to be a revascularization strategy superior to traditional STA-MCA end-to-side anastomosis. In this study, we presented seven cases in which a STA-MCA side-to-side microvascular anastomosis was performed with a 4-5 mm long arteriotomy using the in-situ intraluminal suturing technique.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!