• Biblioteca del Dipartimento di Bioingegneria del Politecnico di Milano

    Via C. Golgi, 39 (4.piano) 20133 Milano tel02/23993300 fax0223993329 Messenger:bibliobioingpolimi@hotmail.it Skype: bibliobioingpolimi Aggiungici al tuo iGoogle Add to Google Creative Commons License
    Questo/a opera è pubblicato sotto una Licenza Creative Commons
  • Le nostre dritte (del.icio.us)

  • I più letti

  • Foto @lla tua biblioteca

  • Archivi

  • Link più cliccati

    • Nessuna
  • Sono passati di qui...

    • 230,387 visitatori
  • Annunci

Seminario: biomeccanica dell’attivazione piastrinica 28/7/06


Venerdì 28/7/2006 presso l’aula seminari del Dipartimento di Bioingegneria alle ore 11:00. si svolgerà un seminario di studio sulla biomeccanica della attivazione piastrinica e dei fenomeni di trombogenesi con la partecipazione del Prof. Danny Bluestein, della Stony Brook University di New York e direttore del Corso di Studi in Biomedical Engineering.

L’intervento del prof. Bulestein avrà come titolo Research Approaches for Studying Thrombosis in Blood Recirculating Devices and in Cardiovascular Pathologies



Pubblichiamo un breve abstract dell’intervento


Thrombus formation in prosthetic cardiovascular devices and in arterial pathologies is associated with elevated hemodynamic stresses that may induce platelet activation, thrombus formation, and potentiate their interaction with the endothelium. In vitro studies were conducted to estimate the thrombogenic potential of various Prosthetic Heart Valve (PHV) designs. A new polymer trileaflet design was tested for its thrombogenic potential and compared to that of existing prosthetic heart valves (PHVs) routinely implanted in patients: a St. Jude Medical bileaflet mechanical heart valve (MHV) and a St. Jude porcine bioprosthetic tissue valve. The valves were mounted in a left ventricular assist device (LVAD) and the procoagulant activity of the platelets was measured using an innovative platelet activation state (PAS) assay.

Complementary in vivo studies were conducted in the sheep model to study the effects of valve implantation on platelet activity and the risk of cardioembolic stroke. Sheep with implanted valves had increased level of platelet activity, as measured with the PAS assay. Transcranial Doppler measurements indicated a significant increase in the amount of microembolic signals, as measured in the carotid artery of the sheep after valve implantation.

Mechanisms of thrombus formation were investigated using numerical simulations of transient non-Newtonian blood flow patterns in various PHVs, using advanced turbulence models. Platelet damage accumulation model incorporating damage history (senescence) was developed to estimate platelet activation resulting from the combined effect of flow induced stresses and exposure time in the device. Additionally, Fluid Structure Interaction (FSI) simulations of flow past ATS and SJM bileaflet valves were conducted and platelet activation damage averaged over a large number of trajectories within the flow field.

FSI simulations were also conducted in a model of a vulnerable plaque- a pathology that prompts strokes and fatal heart attacks (sudden cardiac death), and in abdominal aortic aneurysms (AAA) reconstructed from patients CT images, in order to predict plaque vulnerability and AAA risk of rupture. For the vulnerable plaque the analysis indicates regions where a combination of elevated strains in the vessel wall and shear stresses induced by the flow, combined with the fibrous cap thickness, enhance the plaque vulnerability and may lead to rapid thrombus formation. The role of calcification in the plaque was examined, indicating that it significantly increases the plaque vulnerability. For the AAA, the role of intraluminal (ILT) thrombus in the AAA was examined and used to predict potential rupture locations.

A discrete multiple particles dynamics multiscale approach, which widely departs from the traditional continuum approach, is being developed to study flow induced thrombosis. The multiscale modeling concentrates on flow regions in devices and pathologies that have a high propensity to activate platelets and to form aggregates. Forces and potentials around particles representing platelets are characterized using Lennard-Jones equations and a summation of viscosity forces, to calculate the motion of particles representing the different phases in the domain.



8 Risposte

  1. These are actually impressive ideas in concerning blogging.
    You have touched some pleasant factors here. Any way keep
    up wrinting.

  2. Hi! I know this is kind of off topic but I was wondering if
    you knew where I could locate a captcha plugin for my comment form?
    I’m using the same blog platform as yours and I’m having trouble finding one?

    Thanks a lot!

  3. Many times the body will repair itself and produce more platelets if given the needed rest from these
    foods. You can improve you low platelet count by following a low calorie diet that has only moderate amounts of protein.
    That also means any thing with high fructose corn syrup in it.

  4. Hence, it the new year’s resolution of almost everyone to be
    more healthy and lose a pound or two in the coming year by exercising and eating right.
    This chart is still true today, but the important question remains,
    is using fat as our principal fuel the best way to stay lean.
    Obviously, if you choose a steep hill for an interval, your
    movement will not be fast per se, but it should be as fast as possible.

  5. Hi, i read your blog from time to time and i own a similar one
    and i was just curious if you get a lot of spam comments? If so how do you stop it,
    any plugin or anything you can recommend? I get so much lately it’s driving me insane so any assistance is very much appreciated.

  6. I really like what you guys are usually up too. This type of
    clever work and coverage! Keep up the terrific works guys I’ve included you guys to our blogroll.

  7. I have to thank you for the efforts you’ve put in penning this blog. I am hoping to view the same high-grade content by you later on as well. In truth, your creative writing abilities has inspired me to get my own, personal website now 😉

  8. It is estimated that more than half of adult Americans use vitamin supplements regularly.
    Look for details like these: For herbs, the specific species and part of the
    plant used should be listed. – People who are vegetarians
    and can’t find the proper sources to supplement their diet.


Inserisci i tuoi dati qui sotto o clicca su un'icona per effettuare l'accesso:

Logo WordPress.com

Stai commentando usando il tuo account WordPress.com. Chiudi sessione / Modifica )

Foto Twitter

Stai commentando usando il tuo account Twitter. Chiudi sessione / Modifica )

Foto di Facebook

Stai commentando usando il tuo account Facebook. Chiudi sessione / Modifica )

Google+ photo

Stai commentando usando il tuo account Google+. Chiudi sessione / Modifica )

Connessione a %s...

%d blogger hanno fatto clic su Mi Piace per questo: