The instantaneous wave-free ratio (iFR) is a recently introduced vasodilator-free index to assess the functional severity of coronary stenosis in the resting state, while fractional flow reserve (FFR) is the gold standard index in hyperemia. The computed instantaneous wave-free ratio (CT-iFR) is a noninvasive method to estimate iFR using computer simulations. Here, we developed a vessel-length-based CT-iFR method in patient-specific models of coronary arteries.
View Article and Find Full Text PDFRationale: Predicting the sites in coronary arteries that are susceptible to plaque deposition is essential for the development of clinical treatment strategies and prevention. However, to date, no physiological biomarkers for this purpose have been developed. We hypothesized that the possibility of plaque deposition at a specific site in the coronary artery is associated with wall shear stress (WSS) and fractional flow reserve (FFR).
View Article and Find Full Text PDFA multielectrode array (MEA) was fabricated with electrodes consisting of iridium oxide (IrOx) electrochemically deposited on nanoporous gold (NPG) to improve the moderate charge injection limit (ca. 1 mC cm) of NPG MEA. IrOx was electrodeposited by performing cyclic voltammetry with an IrOx deposition solution.
View Article and Find Full Text PDFObjective: As the stenotic severity of a patient increases, fractional flow reserve (FFR) decreases, whereas the maximum wall shear stress (WSSmax) increases. However, the way in which these values can change according to stenotic severity has not previously been investigated. The aim of this study is to devise a virtual stenosis model to investigate variations in the coronary hemodynamic parameters of patients according to stenotic severity.
View Article and Find Full Text PDFIn order to complement the high impedance electrical property of gold nanoparticles (Au NPs) we have performed electro-co-deposition of gold-platinum nanoparticles (Au-Pt NPs) onto the Au multi-electrode array (MEA) and modified the Au-Pt NPs surface with cell adhesive poly-D-lysine via thiol chemistry based covalent binding. The Au-Pt NPs were analyzed to have bimetallic nature not the mixture of Au NPs and Pt NPs by X-ray diffraction analysis and to have impedance value (4.0 × 10(4) Ω (at 1 kHz)) comparable to that of Pt NPs.
View Article and Find Full Text PDFObjective: Nanoporous gold (Au) structures can reduce the impedance and enhance the charge injection capability of multi-electrode arrays (MEAs) used for interfacing neuronal networks. Even though there are various nanoporous Au preparation techniques, fabrication of MEA based on low-cost electro-codeposition of Ag:Au has not been performed. In this work, we have modified a Au MEA via the electro-codeposition of Ag:Au alloy, followed by the chemical etching of Ag, and report on the in vitro extracellular recording and stimulation performance of the nanoporous Au-modified MEA.
View Article and Find Full Text PDFIn this work, Cath.a-differentiated (CAD) cells were used in place of primary neuronal cells to assess the performance of vertically aligned carbon nanotubes (VACNTs) multi-electrode arrays (MEA). To fabricate high-performance MEA, VACNTs were directly grown on graphene/Pt electrodes via plasma enhanced chemical deposition technique.
View Article and Find Full Text PDFObjectives: To examine the possibility of acupuncture as a new promising treatment to prevent delayed cerebral vasospasm, retrospective comparison was done of patient outcomes in patients with subarachnoid hemorrhage (SAH) treated with and without acupuncture.
Materials And Methods: Twenty (20) patients with SAH were treated after their ruptured aneurysms had been secured. Acupuncture treatments were applied to the bilateral Zusanli (ST36) and Neiguan (PC6) once a day for 2 weeks, starting within 3 days of the aneurysm rupture.
Neurointervention
September 2012
Early spontaneous recanalization of the middle cerebral artery in acute ischemic phase artery is not uncommon, whereas the late spontaneous recanalization of chronic occluded artery is a very rare phenomenon and exact incidence and the timing of this event have not been quantified. We present a case in which late spontaneous recanalization of long-lasting middle cerebral artery occlusion occurred in the absence of surgical, endovascular and thrombolytic treatments.
View Article and Find Full Text PDFObjective: To evaluate characteristics of cognitive impairments according to the location of aneurysmal subarachnoid hemorrhage (SAH) using a computerized neuropsychological test (CNT).
Method: A total of 211 patients were transferred to our rehabilitation department after becoming neurologically stable following aneurysmal SAH. Twenty four of the 211 patients met the inclusion criteria and participated in a screening test using the mini-mental state examination (MMSE).
Two cases of the posterior fossa dissecting aneurysm associated with a double origin of the posterior inferior cerebellar artery (DOPICA) causing subarachnoid hemorrhage are presented. After observing a relationship between the aneurysm and DOPICA on a three dimensional rotational angiogram (3DRA), the dissecting aneurysms were successfully obliterated by surgical trapping and endovascular internal trapping, respectively. This report warrants suspecting DOPICA of an associating anomaly predisposing to dissecting aneurysm in the vertebral artery-posterior inferior cerebellar artery territory and highlights the role of 3DRA in pretreatment evaluation of unusual aneurysms accompanying a particular anatomical variation.
View Article and Find Full Text PDFWe describe photopatterning technique that employs the photodegradation of cell-adhesive-modified poly(ethyleneimine) (m-PEI) to fabricate precise micropatterns on the indium tin oxide (ITO) substrate for guided neuronal growth. The photodegradation of m-PEI coated on hydroxyl group-terminated ITO substrate created micropatterns over a large area through deep UV irradiation. The photopatterned m-PEI layer can effectively guide neurite outgrowth and control neurite extensions from individual neurons.
View Article and Find Full Text PDFA 47-year-old man presented with a subarachnoid hemorrhage (SAH) and right cerebellar hematoma was referred for evaluation. Cerebral angiography revealed a distal anterior inferior cerebellar artery (AICA) aneurysm associated with an arteriovenous malformation (AVM). Successful obliteration and complete removal of the aneurysm and AVM were obtained using transcortical approach under the guidance of neuronavigation system.
View Article and Find Full Text PDFA rare case of ruptured aneurysm associated with multiple A(1) fenestrations resembling plexiform network was demonstrated by 3D angiography. A 56-year-old female presented with a ruptured aneurysm in the A(2) segment of the left distal anterior cerebral artery associated with the right A(1) fenestration. The ruptured aneurysm was occluded with surgical neck clipping via interhemispheric approach without neurological deficit.
View Article and Find Full Text PDFThe present study used immunohistochemistry to investigate p53 expression in rat brain following transient occlusion of the middle cerebral artery. In the control group, no p53-immunoreactive cells were found in any region of the central nervous system. P53 expression in reactive astrocytes was not obvious in the forebrain one day or three days following ischemic insults.
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