Pioneering artificial intelligence-based real time assistance for intracranial liquid embolization in humans: an initial experience.

BACKGROUND: Liquid embolization in neuroendovascular procedures carries the risk of embolizing an inappropriate vessel. Operators must pay close attention to multiple vessels during the procedure to avoid ischemic complications. We report our experience with real time artificial intelligence (AI) assisted liquid embolization and evaluate its performance. METHODS: An AI-based system (Neuro-Vascular Assist, iMed technologies, Tokyo, Japan) was used in eight endovascular liquid embolization procedures in two institutions. The software automatically detects liquid embolic agent on biplane fluoroscopy images in real time and notifies operators when the agent reaches a predefined area. Safety, efficacy, and accuracy of the notifications were evaluated using recorded videos. RESULTS: Onyx or n-butyl-2-cyanoacrylate (NBCA) was used in the treatment of arteriovenous malformation, dural arteriovenous fistula, meningioma, and chronic subdural hematoma. The mean number of true positive and false negative notifications per case was 31.8 and 2.8, respectively. No false positive notifications occurred. The precision and recall of the notifications were 100% and 92.0%, respectively. In 28.3% of the true positive notifications, the operator immediately paused agent injection after receiving the notification, which demonstrates the potential effectiveness of the AI-based system. No adverse events were associated with the notifications. CONCLUSIONS: To the best of our knowledge, this is the first report of real time AI assistance with liquid embolization procedures in humans. The system demonstrated high notification accuracy, safety, and potential clinical usefulness in liquid embolization procedures. Further research is warranted to validate its impact on clinical outcomes. AI-based real time surgical support has the potential to advance neuroendovascular treatment.

Real time artificial intelligence assisted carotid artery stenting: a preliminary experience.

BACKGROUND: Neurointerventionalists must pay close attention to multiple devices on multiple screens simultaneously, which can lead to oversights and complications. Artificial intelligence (AI) has potential application in recognizing and monitoring these devices on fluoroscopic imaging. METHODS: We report out preliminary experience with a real time AI assistance software, Neuro-Vascular Assist (iMed technologies, Tokyo, Japan), in six patients who underwent carotid artery stenting. This software provides real time assistance during endovascular procedures by tracking wires, guiding catheters, and embolic protection devices. The software provides notification when devices move out of a predefined region of interest or off the screen during the procedure. Efficacy, safety, and accuracy of the software were evaluated. RESULTS: The software functioned well without problems and was easily used. Mean number of notifications per procedure was 21.0. The mean numbers of true positives, false positives, and false negatives per procedure were 17.2, 3.8, and 1.2, respectively. Precision and recall were 82% and 94%, respectively. Among the 103 true positive notifications, 24 caused the operator to adjust the inappropriate position of the device (23%), which is approximately four times per procedure. False notifications occurred because of false positive device detection. No adverse events related to the software occurred. No periprocedural complications occurred. CONCLUSIONS: Neuro-Vascular Assist, a real time AI assistance software, worked appropriately and may be beneficial in carotid artery stenting procedures. Future large scale studies are warranted to confirm.

The serum thioredoxin-1 levels are not associated with bronchopulmonary dysplasia and retinopathy of prematurity.

BACKGROUND: We hypothesized that the serum TRX-1 in extremely preterm infants (EPIs) after birth was associated with the development of severe bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP). METHODS: This single-centered retrospective study enrolled EPIs treated at our institution. Serum TRX-1 concentrations of the residual samples taken on admission, day 10-20 of life, and 36-40 weeks of postmenstrual age (PMA) were measured with an enzyme-linked immunosorbent assay. RESULTS: The serum TRX-1 levels on admission were not different between the severe BPD (n = 46) and non-severe BPD groups (n = 67): [median (interquartile range) 147 (73.0-231) vs. 164 (80.5-248) ng/mL] (P = 0.57). These had no significant difference between the severe ROP (n = 47) and non-severe ROP groups (n = 66): [164 (71.3-237) vs. 150 (80.9-250) ng/mL] (P = 0.93). The TRX-1 levels at 10-20 days of life and 36-40 weeks of PMA also had no association with the development of severe BPD and ROP. CONCLUSION: The serum TRX-1 levels after birth are not predictive of severe BPD and ROP. IMPACT: Serum thioredoxin-1 levels in extremely preterm infants on the day of birth are lower than those in term or near-term infants hospitalized for transient tachypnea of the newborn. In extremely preterm infants, the serum thioredoxin-1 levels on the day of birth, at 10-20 days of life, and at postmenstrual age of 36-40 weeks were not associated with severe bronchopulmonary dysplasia and retinopathy of prematurity. The thioredoxin system is under development in extremely preterm infants; however, the serum thioredoxin-1 level is not predictive for severe bronchopulmonary dysplasia and retinopathy of prematurity.

Ultrahigh-throughput screening of Trichoderma reesei strains capable of carbon catabolite repression release and cellulase hyperproduction using a microfluidic droplet platform.

Trichoderma reesei is the most well-known cellulase producer in the biorefinery industry. Its cellulase biosynthesis is repressed by glucose via carbon catabolite repression (CCR), making CCR-releasing strains with cellulase hyperproduction desirable. Here, we employed a microfluidic droplet platform to culture and screen T. reesei mutants capable of CCR release and cellulase overproduction from extensive mutagenesis libraries. With 3 mutagenesis rounds, about 6.20 × 103 droplets were sorted from a population of 1.51 × 106 droplets in a period of 4.4 h; 76 recovery mutants were screened on flask fermentation, and 2 glucose uptake retarded mutants, MG-9-3 and MG-9-3-30, were eventually isolated. We also generated a hypercellulase producer, M-5, with CCR release via a single mutagenesis round. The hyphal morphology and molecular mechanisms in the mutants were analyzed. This versatile approach combined with a comprehensive understanding of CCR release mechanisms will provide innovative and effective strategies for low-cost cellulase production.

Anesthetic Fade in Intraoperative Transcranial Motor Evoked Potential Monitoring Is Mainly due to Decreased Synaptic Transmission at the Neuromuscular Junction by Propofol Accumulation.

BACKGROUND: We previously reported that normalization of motor evoked potential (MEP) monitoring amplitude by compound muscle action potential (CMAP) after peripheral nerve stimulation prevented the expression of anesthetic fade (AF), suggesting that AF might be due to reduced synaptic transfer in the neuromuscular junction. METHODS: We calculated the time at which AF began for each of craniotomy and spinal cord surgery, and examined whether AF was avoided by CMAP after peripheral nerve stimulation normalization in each. Similar studies were also made with respect to the upper and lower limb muscles. RESULTS: AF was observed in surgery lasting 160 minutes for craniotomy and 260 minutes or more for spinal surgery, and 195 minutes in the upper limb muscles and 135 minutes in the lower limb muscles. In all the series, AF could be avoided by CMAP after peripheral nerve stimulation normalization. CONCLUSION: AF of MEP occurred in both craniotomy and spinal cord surgery, and it was also corrected by CMAP after peripheral nerve stimulation. AF is considered to be mainly due to a decrease in synaptic transfer of the neuromuscular junction due to the accumulation of propofol because of the avoidance by CMAP normalization. However, it may be partially due to a decrease in the excitability of pyramidal tracts and α-motor neurons, because AF occurred earlier in the lower limb muscles than in the upper limb muscles.

Aphagia Strongly Suspected to Be Caused by an Allergic Reaction to a Gelatin-based Hemostatic Agent after Anterior Cervical Decompression and Fusion for Central Cervical Cord Injury.

Gelatin-based hemostatic agents are widely used in neurosurgery. This is a case of postoperative aphagia strongly suspected to be caused by an allergic reaction to a gelatin-based hemostatic agent after anterior cervical decompression and fusion for central cervical cord injury. A 55-year-old man underwent cervical anterior decompression and fusion at the C3/4 and 4/5 levels for central cervical cord injury. Immediately after the surgery, he could not swallow saliva at all, but his voice was not hoarse. Postoperative cervical computed tomography and magnetic resonance imaging showed significant edema from the post-hypopharynx wall to the front of the vertebral body. The retropharyngeal space was remarkably enlarged to 15.8 mm with cervical spine X-rays. Without neurological symptom improvement, his condition was diagnosed as marked edema of the area where Surgiflo (porcine-derived gelatin-based hemostatic agent; Johnson & Johnson Wound Management, Somerville, NJ, USA) had been applied during the operation. It was strongly suspected to be caused by an allergic response to the porcine-derived gelatin. When methylprednisolone 1000 mg was administered for 3 days from the 5th postoperative day, swallowing became almost normal within a few hours after the initial administration, and his neurological symptoms improved. The patient left the hospital on the 12th day after the operation. Before using porcine-derived gelatin products during surgery, special consideration should be given to patients with an allergy history before surgery.

[A case of elderly-onset myasthenia gravis mimicking stroke with dysarthria and left upper extremity paresis].

An 80-year-old woman presented with sudden-onset dysarthria and left-side dominant quadriparesis and transferred to our hospital. A neurologic examination revealed slurred speech, prominent left upper extremity weakness and mild weakness of the other extremities. Brain MRI revealed a history of right-side cerebral artery bypass surgery, but no new lesions indicative of stroke. Left upper extremity weakness had improved soon after admission, so a transient ischemic attack was suspected. After admission, the dysarthria fluctuated. The patient's respiratory condition deteriorated several days later and she required ventilation support. Assessment of the cause of the respiratory failure revealed positive muscle-specific kinase (MuSK) antibodies, which suggested myasthenia gravis (MG). The symptoms gradually improved with immunotherapy and we were able to completely withdraw her from the ventilator after a few months. There were some reports that dysphagia and dysarthria present suddenly like stroke without fluctuation of symptoms in elderly-onset MG. It is necessary to note that MG diagnosis may be difficult if elderly patients have multiple comorbidities and unclear diurnal fluctuations.

The identified clinical features of Parkinson's disease in homo-, heterozygous and digenic variants of PINK1.

To investigate the prevalence and genotype-phenotype correlations of phosphatase and tensin homolog induced putative kinase 1 (PINK1) variants in Parkinson's disease (PD) patients, we analyzed 1700 patients (842 familial PD and 858 sporadic PD patients from Japanese origin). We screened the entire exon and exon-intron boundaries of PINK1 using Sanger sequencing and target sequencing by Ion torrent system. We identified 30 patients with heterozygous variants, 3 with homozygous variants, and 3 with digenic variants of PINK1-PRKN. Patients with homozygous variants presented a significantly younger age at onset than those with heterozygous variants. The allele frequency of heterozygous variants in patients with age at onset at 50 years and younger with familial PD and sporadic PD showed no differences. [123I]meta-iodobenzylguanidine (MIBG) myocardial scintigraphy indicated that half of patients harboring PINK1 heterozygous variants showed a decreased heart to mediastinum ratio (12/23). Our findings emphasize the importance of PINK1 variants for the onset of PD in patients with age at onset at 50 years and younger and the broad spectrum of clinical symptoms in patients with PINK1 variants.

[A Case of Pol III-related Leukodystrophy with Homozygous Mutation in POLR3A].

We describe a 27-year-old man with mental retardation, symptomatic epilepsy, myopia, and cerebellar ataxia without spontaneous puberty whose brain magnetic resonance imaging showed hypomyelination. He had child-like facial appearance, with thin facial hair. He had no underarm and pubic hairs, and his penis was small. Laboratory tests showed low levels of luteinizing hormone, follicle-stimulating hormone, and testosterone. Brain MRI showed diffuse hypomyelination, atrophy of the cerebellum and brainstem, and hypoplastic corpus callosum. Ictal N-isopropyl-p-(indone-123)-iodoamphetamine single photon emission computed tomography (123I-IMP SPECT) revealed hypoperfusion of bilateral frontal cingulate and temporal lobe and cerebellar hemispheres. Homozygous missense mutation c.2350G>A was found in POLR3A and the patient was diagnosed with Pol III-related leukodystrophy, which is a rare disease. We describe the present case in light of the characteristics of the past reports in Japan. (Received April 5, 2016: Accepted June 30, 2016; Published November 1, 2016).

[A case of combined central and peripheral demyelination].

A 22-year-old man had had difficulty running fast since about he was 10 years old. In June 2011, he was referred to us because of worsened unsteady gait. A neurological examination revealed mild ataxic speech, weakness of the four limbs, with spasticity, and pes cavus. Magnetic resonance T2-weighted images showed multiple high-intensity lesions in the bilateral periventricular white matter, brainstem, and thoracic spinal cord. Peripheral nerve conduction studies revealed marked motor conduction velocities were markedly reduced and sensory nerve velocities were not evoked in the upper and lower limbs. A sural nerve biopsy showed highly active demyelinating lesions. The patient was treated with high-dose steroid therapy (intravenous methylprednisolone, 1,000 mg/day × 3 days) followed by self-injection of interferon ß. With these treatments, his symptoms gradually improved. In this case, we could not detect the causative factors, and all autoantibodies tested, except for the anti-neurofascin antibody, were negative. The anti-neurofascin antibody might induce demyelination in the central and peripheral nervous systems. However, in the literature, the evidence of an association between this antibody and these clinical characteristics is not conclusive. We need more studies on the pathogenesis of combined central and peripheral demyelination to establish more effective therapies.

[A case of bilateral auricular chondritis with anti-glutamate receptor (GluRε2) antibody-positive non-herpetic acute limbic encephalitis].

A 62-year-old man experienced pain and swelling in both of his auricles. One and a half months later, he was referred to us because of a memory disturbance. A neurological examination revealed disorientation and recent memory impairment. Diffusion-weighted and fluid-attenuated inversion recovery magnetic resonance images showed high intensity and swelling lesions in the bilateral medial temporal regions. In cerebrospinal fluid, mononuclear cell counts and total protein concentration were increased, but a herpes polymerase chain reaction was negative. Thus, he was suspected to have non-herpetic acute limbic encephalitis (NHALE). In addition, relapsing polychondritis (RP) was suspected because of the bilateral auricular chondritis and type-II collagen antibody positivity in the serum. He was treated with high-dose steroid therapy (two cycles of intravenous methylprednisolone, 500 mg per day for 3 days), which was followed by oral steroid therapy. With these treatments, his symptoms, including the painful auricular swelling and memory disturbance, gradually improved. This case exhibited anti-glutamate receptor (GluRε2) antibody positivity in both serum and cerebrospinal fluid, but anti-N-methyl-D-aspartate glutamate receptor antibody (NR1 + NR2) by cell-based assay negative in cerebrospinal fluid. Although a vascular mechanism of NHALE that is associated with RP has been suggested in the literature, this autoantibody might have induced NHALE as the mechanism of neuronal damage to target neuron in our case. More studies on the pathogenesis of NHALE that is associated with RP are needed.

Proximal stenosis may induce initiation of cerebral aneurysms by increasing wall shear stress and wall shear stress gradient.

Hemodynamic parameters, such as wall shear stress (WSS), WSS gradient (WSSG), aneurysm formation indicator (AFI), or gradient oscillatory number (GON), have been proposed to be linked to initiation of cerebral aneurysms. However, how such conditions occur in humans is unclear. We encountered a rare and interesting case to address this issue. A patient had a newly formed aneurysm with proximal stenosis, which was confirmed by serial imagings. We made two pre-aneurysm models: one with stenosis and the other without stenosis. We performed computational fluid dynamics simulations for these models. Owing to jet flow caused by the stenosis, the maximum WSS and WSSG on the aneurysm initiation site were approximately doubled and tripled, respectively. However, the oscillatory shear index (OSI), AFI, and GON did not change substantially by the stenosis. Computer simulations using artificial vascular models with different degrees of proximal stenosis at different distances demonstrated that oscillatory shear index, AFI, and GON did not change substantially by the stenosis. These results showed that proximal stenosis caused high WSS and high WSSG at the aneurysm initiation site, possibly leading to aneurysm initiation. Proximal stenosis may be a potential factor to induce initiation of one class of cerebral aneurysms by increasing WSS and WSSG.

Multiple and cooperative binding of fluorescence light-up probe thioflavin T with human telomere DNA G-quadruplex.

Thioflavin T (ThT), a typical probe for protein fibrils, also binds human telomeric G-quadruplexes with a fluorescent light-up signal change and high specificity against DNA duplexes. Cell penetration and low cytotoxicity of fibril probes having been widely established, modifying ThT and other fibril probes is an attractive means of generating new G-quadruplex ligands. Thus, elucidating the binding mechanism is important for the design of new drugs and fluorescent probes based on ThT. Here, we investigated the binding mechanism of ThT with several variants of the human telomeric sequence in the presence of monovalent cations. Fluorescence titrations and electrospray ionization mass spectrometry (ESI-MS) analyses demonstrated that each G-quadruplex unit cooperatively binds to several ThT molecules. ThT brightly fluoresces when a single ligand is bound to the G-quadruplex and is quenched as ligand binding stoichiometry increases. Both the light-up signal and the dissociation constants are exquisitely sensitive to the base sequence and to the G-quadruplex structure. These results are crucial for the sensible design and interpretation of G-quadruplex detection assays using fluorescent ligands in general and ThT in particular.

Triple antiplatelet therapy with addition of cilostazol to aspirin and clopidogrel for Y-stent-assisted coil embolization of cerebral aneurysms.

BACKGROUND: Dual antiplatelet therapy for stent-assisted coiling of cerebral aneurysms is essential to prevent thromboembolic complications. There is concern that Y-stent-assisted coiling may increase thromboembolic complications compared with coiling with a single stent. Several reports have demonstrated that cilostazol may improve clopidogrel responsiveness. We investigated whether triple antiplatelet therapy with addition of cilostazol to aspirin plus clopidogrel for Y-stents can prevent thromboembolic events. METHODS: Between July 2010 and October 2012, we treated 40 consecutive aneurysms with coil embolization using Enterprise stents. At the peri-procedural period, dual antiplatelet agents (100 mg aspirin and 75 mg clopidogrel) were used for the single stent group (n = 36), and triple antiplatelet agents (addition of 200 mg cilostazol) were used for the Y-stent group (n = 4). We evaluated post-operative diffusion-weighted imaging (DWI) and any complications. We assessed the following for statistical analysis: age, sex, aneurysm location, shape, and size, neck size, size of parent vessels, and stent length. RESULTS: We found two neurological peri-procedural complications: one transient ischemic attack and one infarction. Both complications belonged to the Y-stent group, which was a significant factor of thromboembolic events (P = 0.008). There were no other significant factors related to neurological complications or positive DWI. For subgroup analysis of the single stent group, stent length was significantly longer in positive DWI than negative DWI (P = 0.04). In the follow-up period of 20 ± 8.6 months, there were no symptomatic late complications in any patients. CONCLUSIONS: Although the number of patients in the Y-stent group is small, this group had a significantly higher risk of thromboembolic complications. While our protocol of a routine dose of dual antiplatelet therapy may be sufficient for single stent therapy, our protocol of a routine dose of triple antiplatelet therapy for Y-stents may not prevent thromboembolic events. This suggests that evaluation of platelet function may be essential, especially for Y-stents.

Molecular crowding and hydration regulating of G-quadruplex formation.

Intracellular space is highly crowded with soluble and insoluble biomolecules that range from large polymers, such as proteins and nucleic acids, to small molecules, including metabolites and metal ions. It is therefore of interest to understand the effects of molecular crowding on the structure, stability, and function of biomolecules. Moreover, molecular crowding is observed not only intracellularly but also in the extracellular matrix and under the conditions used in in vitro biotechnological and nanotechnological processes. However, most biochemical studies of biomolecules are performed under dilute conditions. Recent studies have demonstrated critical effects of molecular crowding on nucleic acids. In the present study we discuss how molecular crowding affects the properties of G-quadruplexes as well as other non-canonical nucleic acid structures.

Thermodynamics-hydration relationships within loops that affect G-quadruplexes under molecular crowding conditions.

We systematically investigated the effects of loop length on the conformation, thermodynamic stability, and hydration of DNA G-quadruplexes under dilute and molecular crowding conditions in the presence of Na(+). Structural analysis showed that molecular crowding induced conformational switches of oligonucleotides with the longer guanine stretch and the shorter thymine loop. Thermodynamic parameters further demonstrated that the thermodynamic stability of G-quadruplexes increased by increasing the loop length from two to four, whereas it decreased by increasing the loop length from four to six. Interestingly, we found by osmotic pressure analysis that the number of water molecules released from the G-quadruplex decreased with increasing thermodynamic stability. We assumed that base-stacking interactions within the loops not only stabilized the whole G-quadruplex structure but also created hydration sites by accumulating nucleotide functional groups. The molecular crowding effects on the stability of G-quadruplexes composed of abasic sites, which reduce the stacking interactions at the loops, further demonstrated that G-quadruplexes with fewer stacking interactions within the loops released a larger number of water molecules upon folding. These results showed that the stacking interactions within the loops determined the thermodynamic stability and hydration of the whole G-quadruplex.

[Incidence of uveitis in the northern Kyushu region of Japan --comparison between the periods of 1996-2001 and 2003-2008].

PURPOSE: To report the clinical statistical analysis of patients with uveitis in the northern Kyushu region of Japan. SUBJECTS AND METHODS: This retrospective study involved 735 new patients with uveitis who visited the Kyushu university hospital from January 2003 to December 2008. The subjects were classified into four groups; adolescent (0-19 years), young (20-39 years), middle-aged (40-59 years) and old (60 years or older) and were compared with the results of our previous studies. RESULT: This study comprised 343 men and 392 women. The age averaged 47.2 years. Definitive diagnosis was made in 385 cases (52.4%). The most frequent clinical entity was sarcoidosis (9.8%), followed by Vogt-Koyanagi-Harada disease (7.9%), Behçet's disease (7.6%), acute anterior uveitis associated with human leukocyte antigen (HLA)-B27 (4.5%), herpetic iridocyclitis (3.1%), human T-lymphotropic virus type I associated uveitis (HU) (2.7%), and intraocular lymphoma (2.3%). The proportion of unclassified uveitis was large among females in general, and among adolescents in the four groups. The incidence of secondary glaucoma in the whole group of 735 patients with uveitis was 22.2%. Among the patients with ocular hypertension, the proportion of steroid responders was large in the adolescent group. CONCLUSION: Compared with our previous report, this study shows increasing frequency of sarcoidosis and decreasing frequency of Behçet's disease except in the young group. HU showed a decreasing incidence.

Stent-assisted coil embolization and computational fluid dynamics simulations of bilateral vertebral artery dissecting aneurysms presenting with subarachnoid hemorrhage: case report.

BACKGROUND AND IMPORTANCE: A vertebral artery dissecting aneurysm (VADA) is a relatively rare cause of subarachnoid hemorrhage. Bilateral VADAs are even rarer, and management strategies are controversial. We report a case of bilateral VADAs presenting with subarachnoid hemorrhage. We treated the patient by stent-assisted coil embolization of both aneurysms at a single session on the basis of results of preoperative computational fluid dynamic simulations. CLINICAL PRESENTATION: A 48-year-old man presented with subarachnoid hemorrhage resulting from bilateral VADAs. We treated the patient by stent-assisted coil embolization of both aneurysms at a single session. Before the treatment, we performed computational fluid dynamics simulations to predict the ruptured side. We also estimated the increase in wall shear stress on an aneurysm in case of trapping of another aneurysm, which might cause enlargement and rupture of the aneurysm. The treatment was performed successfully. The patient remains neurologically intact at 14 months from the onset. CONCLUSION: Stent-assisted coil embolization of subarachnoid hemorrhage with bilateral VADAs for both sides is a reasonable treatment because it prevents rebleeding and preserves bilateral vertebral arteries without increasing hemodynamic stress. To the best of our knowledge, this is the first report to describe this type of treatment for bilateral VADAs with subarachnoid hemorrhage. Computational fluid dynamics simulations may be useful for developing treatment strategies for aneurysms.

Hemodynamic characteristics at the rupture site of cerebral aneurysms: a case study.

BACKGROUND AND IMPORTANCE: Hemodynamics play an important role in the mechanisms of aneurysm formation, growth, and rupture. However, little is known about the hemodynamics of rupture sites. CLINICAL PRESENTATION: We incidentally acquired 3-dimensional images before and at the moment of rebleeding of a cerebral aneurysm in a patient. Comparison of these 2 images enabled precise identification of the rupture site. On the basis of computational fluid dynamics simulation, we propose that there are characteristic hemodynamic parameters of the rupture site in cerebral aneurysms. We evaluated flow velocity, wall shear stress (WSS), pressure, and the oscillatory shear index to determine characteristic parameters at the rupture site. Among the hemodynamic parameters in the cardiac cycle, the rupture site was most markedly distinguished by a combination of low WSS at end diastole and high pressure at peak systole. The flow patterns around the rupture site uniquely changed in the cardiac cycle. The rupture site was an impingement zone at peak systole. Flow separation at the rupture site was observed at end diastole. CONCLUSION: In this case, a region with low WSS at end diastole and high pressure at peak systole was at the rupture site. A possible mechanism of rupture in this particular aneurysm is that low WSS at end diastole caused degeneration and thinning of the aneurysm wall and that high pressure at peak systole (impingement zone) resulted in rupture of the thinning wall.

Phthalocyanines: a new class of G-quadruplex-ligands with many potential applications.

A G-quadruplex is a four-stranded DNA structure featuring stacked guanine tetrads, G-quartets. Formation of a G-quadruplex in telomere DNA can inhibit telomerase activity; therefore, development of G-quadruplex-ligands, which induce and/or stabilize G-quadruplexes, has become an area of great interest. Phthalocyanine derivatives have substantial potential as high-affinity G-quadruplex-ligands because these planar chromophores are similar in size and shape to the G-quartets. Here, we focus on the latest findings on phthalocyanine derivatives as G-quadruplex-ligands, and discuss the mechanisms by which phthalocyanines bind to G-quadruplexes with high affinity and selectivity. We also discuss potential biomedical and organic electronic applications of phthalocyanines that are dependent on their photophysical properties.