Identification of Vortex Cores in Cerebral Aneurysms on 4D Flow MRI

BACKGROUND AND PURPOSE

The complexity and instability of the vortex flow in aneurysms are factors related to the rupture risk of unruptured cerebral aneurysms. We identified aneurysm vortex cores on 4D flow MR imaging and examined the relationship of these factors with the characteristics of cerebral aneurysms.

MATERIALS AND METHODS

We subjected 40 aneurysms (37 unruptured, 3 ruptured) to 4D flow MR imaging. We visualized streamlines with velocities below the threshold-that is, a percentage value of the aneurysm maximum inflow velocity-and progressively decreased the threshold to identify vortex cores as thin, streamline bundles with minimum velocities. Complexity and stability were compared in aneurysms with a smooth surface and those with blebs or daughter sacs.

RESULTS

The threshold for visualizing vortex cores ranged from 3% to 13% of the maximum inflow velocity. Vortex cores could be visualized in 38 aneurysms; in 2, they were not visualized through the cardiac cycle. A simple flow pattern (single vortex core) was identified in 27 aneurysms; the other 13 exhibited a complex flow pattern. The cores were stable in 32 and unstable in 8 aneurysms. Significantly more aneurysms with-than-without blebs or daughter sacs had a complex flow pattern (P = .006). Of the 3 ruptured aneurysms, 1 aneurysm had an unstable vortex core; in the other 2, the vortex core was not visualized.

CONCLUSIONS

The identification of vortex cores on 4D flow MR imaging may help to stratify the rupture risk of unruptured cerebral aneurysms.

Intratumoural immune cell landscape in germinoma reveals multipotent lineages and exhibits prognostic significance

AIMS

Alterations in microenvironments are a hallmark of cancer, and these alterations in germinomas are of particular significance. Germinoma, the most common subtype of central nervous system germ cell tumours, often exhibits massive immune cell infiltration intermingled with tumour cells. The role of these immune cells in germinoma, however, remains unknown.

METHODS

We investigated the cellular constituents of immune microenvironments and their clinical impacts on prognosis in 100 germinoma cases.

RESULTS

Patients with germinomas lower in tumour cell content (i.e. higher immune cell infiltration) had a significantly longer progression-free survival time than those with higher tumour cell contents (P = 0.03). Transcriptome analyses and RNA in-situ hybridization indicated that infiltrating immune cells comprised a wide variety of cell types, including lymphocytes and myelocyte-lineage cells. High expression of CD4 was significantly associated with good prognosis, whereas elevated nitric oxide synthase 2 was associated with poor prognosis. PD1 (PDCD1) was expressed by immune cells present in most germinomas (93.8%), and PD-L1 (CD274) expression was found in tumour cells in the majority of germinomas examined (73.5%).

CONCLUSIONS

The collective data strongly suggest that infiltrating immune cells play an important role in predicting treatment response. Further investigation should lead to additional categorization of germinoma to safely reduce treatment intensity depending on tumour/immune cell balance and to develop possible future immunotherapies.

Synthesis and reactivity of a ruthenocene-type complex bearing an aromatic π-ligand with the heaviest group 14 element

An anionic ruthenocene with an η⁵-coordinating plumbole ligand was prepared and reacted with electrophiles to afford plumbole complexes.

An anionic ruthenocene derived from a dilithioplumbole complex was prepared. In the complex, the plumbole ligand coordinates a ruthenium atom in an η⁵-fashion, similar to the cyclopentadienyl ligand in ferrocene. The ruthenocene that has the aromatic π-ligand with the heaviest group 14 element reacted with electrophiles to afford the plumbole complexes wherein the plumbole ligands show deviation from planarity, in contrast to the planar plumbole ring in the anionic ruthenocene. The bent angles of the plumbole ligands are dependent on the substituents on the lead atoms. Cyclic voltammetry measurements revealed that the plumbole complexes are oxidized more easily than the corresponding stannole complexes.

Inflow Jet Patterns of Unruptured Cerebral Aneurysms Based on the Flow Velocity in the Parent Artery: Evaluation Using 4D Flow MRI

BACKGROUND AND PURPOSE

Inflow jet characteristics may be related to aneurysmal bleb formation and rupture. We investigated the visualization threshold on the basis of the flow velocity in the parent artery to classify the inflow jet patterns observed on 4D flow MR imaging.

MATERIALS AND METHODS

Fifty-seven unruptured aneurysms (24 bifurcation and 33 sidewall aneurysms) were subjected to 4D flow MR imaging to visualize inflow streamline bundles whose velocity exceeded visualization thresholds corresponding to 60%, 75%, and 90% of the maximum flow velocity in the parent artery. The shape of the streamline bundle was determined visually, and the inflow jet patterns were classified as concentrated, diffuse, neck-limited, and unvisualized.

RESULTS

At the 75% threshold, bifurcation aneurysms exhibited a concentrated inflow jet pattern at the highest rate. At this threshold, the inflow jets were concentrated in 13 aneurysms (group C, 22.8%), diffuse in 18 (group D, 31.6%), neck-limited in 11 (group N, 19.3%), and unvisualized in 15 (group U, 26.3%). In 16 (28.1%) of the 57 aneurysms, the inflow jet pattern was different at various thresholds. Most inflow parameters, including the maximum inflow velocity and rate, the inflow velocity ratio, and the inflow rate ratio, were significantly higher in groups C and D than in groups N and U.

CONCLUSIONS

The inflow jet pattern may depend on the threshold applied to visualize the inflow streamlines on 4D flow MR imaging. For the classification of the inflow jet patterns on 4D flow MR imaging, the 75% threshold may be optimal among the 3 thresholds corresponding to 60%, 75%, and 90% of the maximum flow velocity in the parent artery.

Diverse coordination modes in tin analogues of a cyclopentadienyl anion depending on the substituents on the tin atom

The coordination mode of stannole monoanion ligands is highly dependent on the types of substituents on the tin atom.

A reversible two-electron redox system involving a divalent lead species

A reversible interconversion between Pb(ii) and its dianionic species bearing organic substituents is described.

Parent artery curvature influences inflow zone location of unruptured sidewall internal carotid artery aneurysms

BACKGROUND AND PURPOSE

Future aneurysmal behaviors or treatment outcomes of cerebral aneurysms may be related to the hemodynamics around the inflow zone. Here we investigated the influence of parent artery curvature on the inflow zone location of unruptured sidewall internal carotid artery aneurysms.

MATERIALS AND METHODS

In 32 aneurysms, the inflow zone location was decided by 4D flow MR imaging, and the radius of the parent artery curvature was measured in 2D on an en face image of the section plane corresponding to the aneurysm orifice.

RESULTS

The inflow zone was on the distal neck in 10 (group 1, 31.3%), on the lateral side in 19 (group 2, 59.4%), and on the proximal neck in 3 (group 3, 9.4%) aneurysms. The radius in group 1 was significantly larger than that in group 2 (8.3 mm [4.5 mm] versus 4.5 mm [1.9 mm]; median [interquartile range]; P < .0001). All 7 aneurysms with a radius of >8.0 mm were in group 1. All 18 aneurysms with a radius of <6.0 mm were in group 2 or 3. In two group 3 aneurysms, the inflow zone was located in a part of the neck extending beyond the central axis of the parent artery.

CONCLUSIONS

The inflow zone locations of sidewall aneurysms can be influenced by the parent artery curvature evaluated in 2D on an en face image of the section plane corresponding to the aneurysm orifice.

Identification of the inflow zone of unruptured cerebral aneurysms: comparison of 4D flow MRI and 3D TOF MRA data

BACKGROUND AND PURPOSE

The hemodynamics of the inflow zone of cerebral aneurysms may be a key factor in coil compaction and recanalization after endovascular coil embolization. We performed 4D flow MR imaging in conjunction with 3D TOF MRA and compared their ability to identify the inflow zone of unruptured cerebral aneurysms.

MATERIALS AND METHODS

This series comprised 50 unruptured saccular cerebral aneurysms in 44 patients. Transluminal color-coded 3D MRA images were created by selecting the signal-intensity ranges on 3D TOF MRA images that corresponded with both the luminal margin and the putative inflow.

RESULTS

4D flow MR imaging demonstrated the inflow zone and yielded inflow velocity profiles for all 50 aneurysms. In 18 of 24 lateral-projection aneurysms (75%), the inflow zone was located distally on the aneurysmal neck. The maximum inflow velocity ranged from 285 to 922 mm/s. On 4D flow MR imaging and transluminal color-coded 3D MRA studies, the inflow zone of 32 aneurysms (64%) was at a similar location. In 91% of aneurysms whose neck section plane angle was <30° with respect to the imaging section direction on 3D TOF MRA, depiction of the inflow zone was similar on transluminal color-coded 3D MRA and 4D flow MR images.

CONCLUSIONS

4D flow MR imaging can demonstrate the inflow zone and provide inflow velocity profiles. In aneurysms whose angle of the neck-section plane is obtuse vis-a-vis the imaging section on 3D TOF MRA scans, transluminal color-coded 3D MRA may depict the inflow zone reliably.

Visualization of angiographical arteriovenous shunting in perisylvian glioblastomas

BACKGROUND

Arteriovenous shunting visualized by angiography is one of the major features of glioblastomas, and the visualization is dependent on the presence of extensive shunting. Extensive arteriovenous shunting is associated with the risk of poorly controlled intraoperative bleeding. When a tumor with extensive arteriovenous shunting is located in close proximity to the eloquent regions of the brain, a meticulous surgical procedure is necessary. In the present study, the site-oriented visualization of angiographical arteriovenous shunting was evaluated from the perspective of surgical treatment, with a particular focus on the perisylvian region that is in close proximity to motor and language regions (dominant hemisphere), as well as large arteries and veins.

METHODS

Twenty-six consecutive patients underwent a resection of glioblastoma between February 2007 and September 2012. All patients were presurgically examined using digital subtraction angiography. The patients were subdivided into the following two groups based on the location of the tumor: 1) perisylvian glioblastoma (18 patients) and 2) non-perisylvian glioblastoma (eight patients). Angiography to detect the arteriovenous shunting was performed. In addition, the number of intratumoral vessels, tumor proliferative activity (MIB-1 labeling index), and volume of intraoperative bleeding were evaluated and compared between the two groups.

RESULTS

Angiographical arteriovenous shunting was definitively visualized in 13 of 18 (72 %) perisylvian glioblastomas, in contrast to only one of eight (13 %) non-perisylvian glioblastomas (p = 0.007). There were no significant differences between the two groups with respect to the number of intratumoral vessels, MIB-1 labeling index, and volume of intraoperative bleeding. However, massive intraoperative bleeding of > 2,000 mL occurred in one perisylvian glioblastoma patient.

CONCLUSIONS

Glioblastomas in the perisylvian region tend to be associated with extensive arteriovenous shunting that can be definitively visualized by performing an angiography. Because arteriovenous shunting carries the risk of intraoperative bleeding, perisylvian glioblastomas-particularly in the dominant hemisphere-should be resected with a meticulous surgical procedure and strategy.

Force detecting gripper and flexible micro manipulator for neurosurgery

In order to realize a less invasive robotic neurosurgery for the deeply seated tumor, a force detecting gripper with a flexible micro manipulator has been developed. Gripping force applied on the gripper is detected by strain gages fit on the gripper clip. Signal is conducted to the amplifier by the cables through the inner pipe of the manipulator. In order to approach to the deeply seated tumor through a narrow hole, a micro manipulator which can flex at the end part to face the gripper for the target and can rotate the closing direction of the gripper at the end of the manipulator has been developed. Some operation test showed that the developed manipulator can approach flexibly to the target, and the taking out force of a target on the soft material was detected clearly.

Silencing of ferrochelatase enhances 5-aminolevulinic acid-based fluorescence and photodynamic therapy efficacy

Background:

Recurrence of glioma frequently occurs within the marginal area of the surgical cavity due to invading residual cells. 5-Aminolevulinic acid (5-ALA) fluorescence-guided resection has been used as effective therapeutic modalities to improve discrimination of brain tumour margins and patient prognosis. However, the marginal areas of glioma usually show vague fluorescence, which makes tumour identification difficult, and the applicability of 5-ALA-based photodynamic therapy (PDT) is hampered by insufficient therapeutic efficacy in glioma tissues.

Methods:

To overcome these issues, we assessed the expression of ferrochelatase (FECH) gene, which encodes a key enzyme that catalyses the conversion of protoporphyrin IX (PpIX) to heme, in glioma surgical specimens and manipulated FECH in human glioma cell lines.

Results:

Prominent downregulation of FECH mRNA expression was found in glioblastoma tissues compared with normal brain tissues, suggesting that FECH is responsible for PpIX accumulation in glioblastoma cells. Depletion of FECH by small interference RNA enhanced PpIX fluorescence after exposure to 5-ALA concomitant with increased intracellular PpIX accumulation in glioma cells. Silencing of FECH caused marked growth inhibition and apoptosis induction by PDT in glioma cells.

Conclusion:

These results suggest that knockdown of FECH is a potential approach to enhance PpIX fluorescent quality for optimising the subjective discrimination of vague fluorescence and improving the effect of 5-ALA-PDT.

Upgrade of the analyzer design for multipoint measurements by a gold neutral beam probe on the GAMMA 10 tandem mirror

The study of the mechanisms of both transport and fluctuations is one of the main issues of fusion plasma researches. Spatial fluctuation structure measurements are important for studying of cross correlation between the two fluctuations. Gold neutral beam probe systems are used in GAMMA 10 tandem mirror plasma device. Currently, the plasma potential and its fluctuations cannot be measured at different radial positions simultaneously. This paper presents the upgrade design of the 45 degrees electrostatic energy analyzer for the simultaneous multipoint measurements of plasma parameters.

Study of radial potential fluctuations by using a gold neutral beam probe system

A study of fluctuation is one of the main issues in fusion plasma researches. The potential and its fluctuation are measured by a gold neutral beam probe (GNBP) in the tandem mirror GAMMA10. Since there is no stable isotope ((197)Au approximately 100%), there are little measurement errors. GNBP system can measure the potential with about +/-30 V of error. The time and spatial resolutions are estimated to be about 3 micros and 5 mm, respectively. During the formation of axial confining potentials, the radial profiles of the potential and its fluctuation were successfully measured in GAMMA10. GNBP is a useful tool for the study of radial potential fluctuation directly in plasmas.

Optical properties of pb(Zr,Ti)O(3) films prepared by aerosol deposition

The optical properties and related band structure of ferroelectric lead zirconate titanate [PZT, Pb(Zr0(0.6)Ti0(0.4))O(3)] films prepared on glass substrates at room temperature by aerosol deposition were investigated. The reflectance and transmittance of the PZT films were measured in the wavelength range from UV to nearinfrared. The measured optical spectra were analyzed using dielectric function models that describe optical transitions in the band gap region. Optical absorption of the as-deposited PZT films was found to be larger than that of the annealed PZT films in the near-infrared wavelength range. The analyzed results indicated that post-deposition annealing increased the band gap energy of the PZT films, corresponding to a decrease in optical absorption.

A clinical study assessing the tolerability and biological effects of infliximab, a TNF-alpha inhibitor, in patients with advanced cancer

BACKGROUND

Tumour necrosis factor-alpha (TNF-alpha) is an important regulator of the chronic inflammation contributing to tumour progression. Infliximab, an anti-TNF-alpha monoclonal antibody was investigated in this trial of patients with advanced cancer. The primary objectives were to determine the safety profile and biological response of infliximab in a cancer population. Clinical response was a secondary objective.

PATIENTS AND METHODS

Forty-one patients received infliximab at 5 mg/kg (n = 21) or 10 mg/kg (n = 20) i.v. at 0 and 2 weeks and then every 4 weeks. Post-treatment samples were measured for changes in plasma and serum TNF-alpha, CCL2, IL-6 and C-reactive protein (CRP).

RESULTS

Infliximab was well tolerated with no dose-limiting toxic effects. At both doses of infliximab, neutralisation of serum TNF-alpha was observed after 1 h while plasma CCL2, IL-6 and serum CRP were decreased 24 and 48 h following infliximab administration. Seven patients experienced disease stablisation (range 10-50+ weeks). There was no evidence of disease acceleration in any patient.

CONCLUSIONS

Infliximab treatment was safe and well tolerated in patients with advanced cancer. There was evidence of biological activity with baseline TNF-alpha and CCL2 being correlated with infliximab response.

273 REMOVAL OF ACROSOME FROM SPERM HEADS IMPROVES DEVELOPMENT OF RAT ZYGOTES THROUGH INTRACYTOPLASMIC SPERM INJECTION

In intracytoplasmic sperm injection (ICSI), sperm chromatin is introduced into the oocyte together with acrosome, which does not enter cytoplasm of oocytes during normal fertilization. In mice, acrosome of sperm head has a detrimental effect on embryonic development of the ICSI oocytes (Morozumi et al. 2006 Proc. Natl. Acad. Sci. USA 103, 17 661–17 666). We examined the effect of acrosome removal of frozen/thawed (F/T) rat sperm on development to term of the ICSI oocytes in order to improve production efficiency of live offspring from F/T rat spermatozoa through ICSI. In experiment 1, epididymal spermatozoa of the Wistar rats were frozen as described previously (Seita et al. 2005 Reprod. Fertil. Dev. 18, 256 abst). The F/T spermatozoa were sonicated to separate sperm heads. The sperm heads were divided into 3 treatment groups; nontreated sperm head (control), sperm heads exposed in 0.02% of Triton X-100 solution for 1 min (TX), sperm heads exposed in 0.02% lysolectin solution for 1 min (LL). Acrosomal status of the sperm heads was then examined by FITC-peanut agglutinin stain. In experiment 2, sperm heads of the control, TX, and LL treatments were microinjected into denuded oocytes obtained from superovulated females (Hirabayashi et al. 2002 Transgenic Res. 11, 221–228). The ICSI oocytes were cultured and observed for the formation of pronuclei (2PN) for 6 h and blastocyst formation at 120 h of culture. In experiment 3, the ICSI oocytes cultured for 6 h were transferred to recipient females to examine development to term. Statistical analyses of the results were carried out by 1-way ANOVA. In experiment 1, the TX (76%) and LL (89%) treatments showed higher rates of acrosome removal than that of the control (24%) group (P < 0.05). In experiment 2, the percentage of 2PN formation at 6 h after ICSI was not significantly different among sperm-treated groups, although the TX (76%) and LL (70%) groups were higher than the control (24%) group at 4 h (P < 0.05). The percentages of blastocyst formation were not significantly different among sperm-treated groups (control: 10%; TX: 25%; and LL: 25%). In experiment 3, the efficiency of development to term of the TX treatment group (21%: 12/57) was significantly higher than the control (5%: 3/55; P < 0.05), although the LL treatment group (16%: 12/75) was not significantly different from the control and TX treatment groups. These results indicate that acrosome removal using TX of F/T rat sperm heads before ICSI improves development to term of the ICSI oocytes. This benefical effect of acrosome removal may be due to the quick release of sperm-activating factors from sperm heads after ICSI in the rat.

Molecular targets of glioma invasion

Glioblastoma multiforme is the most common and lethal primary malignant brain tumor. Although considerable progress has been made in technical proficiencies of surgical and radiation treatment for brain tumor patients, the impact of these advances on clinical outcome has been disappointing, with median survival time not exceeding 15 months. Over the last 30 years, no significant increase in survival of patients suffering from this disease has been achieved. A fundamental source of the management challenge presented in glioma patients is the insidious propensity of tumor invasion into distant brain tissue. Invasive tumor cells escape surgical removal and geographically dodge lethal radiation exposure and chemotherapy. Recent improved understanding of biochemical and molecular determinants of glioma cell invasion provide valuable insight into the underlying biological features of the disease, as well as illuminating possible new therapeutic targets. These findings are moving forward to translational research and clinical trials as novel antiglioma therapies.

The characteristics of simple muscle power by gripping: gender differences and reliability of parameters using various loads

AIM

There are few studies on muscle power during local muscle contractions with a small range of motion such as in gripping. The purposes of this study were to clarify the properties of the developmental phase based on time series of muscle power output, the reliability of the parameters, their relationships and the load intensity derived peak power by gender differences, and to examine the possibility of evaluating muscle power using gripping.

METHODS

Fifteen young males and 15 females participated in this study. Based on a crossover experimental design, each subject carried out 2 explosive grips at 20%, 30%, 40% and 50% loads of maximal using a voluntary grip contraction (MVC). The grip contraction velocities, sampled at 100 Hz, were measured accurately using a power instrument with an accelerometer. Muscle power curves were drawn from the product of the velocity and the set-up load.

RESULTS

The cross-correlation coefficients between the trials for the average curve of the time-series moving distance, the velocity, and the power in any load were very high (over 0.95) in both genders. The reliability of each parameter was mostly good in both genders (intraclass correlation coefficient, ICC>0.75). The peak power curve differed between genders, and the curve around the peak value in females was irregular.

CONCLUSIONS

A gender difference was found in the maximal power and the properties of the power curve. The maximal muscle power appeared at 30-50% MVC in males, and at 20-40% MVC in females. The peak power during the whole contraction, and the time to peak may reflect the conditions throughout the whole of the contraction. The new device used in this study to evaluate local regional muscle power (grip) is a very reliable and useful tool.

Recurrent intracranial esthesioneuroblastoma outside the initial field of radiation with progressive dural and intra-orbital invasion

A 55-year-old man presented with esthesioneuroblastoma in the right paranasal sinuses and orbita, extending into the right anterior and middle cranial fossa. He received a partial resection of tumour and post-operative radiotherapy, which was set with a central focus on the right orbit. Five years later, he came to our hospital with a complaint of left exophthalmos. Neuro-imaging revealed that the tumour recurred on the opposite side of the primary lesion, which was out side the irradiated field, with progressive invasion of the left temporal dura. The residual tumour in the irradiated field had reduced in size. He received gross total resection and post-operative radiotherapy. We would like to emphasize that radiotherapy is an important adjuvant therapy for esthesioneuroblastoma, and that the field setting for radiation therapy is extremely important.