N-2,6-Di(isopropyl)phenyl-2-azaphenalenyl radical cations

N-2,6-Di(isopropyl)phenyl-2-azaphenalenyl radical cations were obtained as a dark brown air-sensitive crystalline compound. The high HOMA values and the ACID calculation indicate relatively high aromatic character of a 5,8-di-tert-butyl derivative, and clean generation of a derivative without tert-butyl groups indicates that the di(isopropyl)phenyl group is sufficient for hampering the formation of the σ-dimer.

Anterior transpetrosal approach and the tumor removal rate, postoperative neurological changes, and complications: experience in 274 cases over 33 years

OBJECTIVE

The authors report on the anterior transpetrosal approach (ATPA) and the results of surgeries performed over a 33-year period for petroclival tumors, including meningioma, trigeminal schwannoma, chordoma, and epidermoid tumor. They analyze early postoperative neurological changes, surgical complications, and trends over the decades.

METHODS

A retrospective analysis of 274 surgical cases that had undergone the ATPA from January 1984 to March 2017 was conducted. Data were collected from charts, clinical summaries, operative records, and operative videos. The analyzed parameters included patient diagnosis, tumor size, disease location, operation date, tumor removal rate, pre- and postoperative neurological symptoms (consciousness level, motor and sensory deficits of the limbs, sensory aphasia, and cranial nerve III-VIII injuries), surgical deaths, and radiologically recognized brain injuries after the operation (contusion, infarction, hemorrhage).

RESULTS

Gross-total resection (GTR) was achieved in 53.5% of the 243 tumors with available data. The GTR rate for meningiomas (148 cases) was 54.1%. Trigeminal schwannomas had a high GTR rate of 87.1%, whereas chordomas had a low GTR rate of 14.3%. The rate of early neurological deterioration immediately after the ATPA, referred to as "early neurological change," was as follows: consciousness disturbance in 1.9% of cases (5 cases), improvement of hemiparesis in 45.0% of cases but deterioration in 8.1% of cases, sensory aphasia in 2.3% of cases due to temporal lobe injury, improvement of cerebellar symptoms in 39.3% of cases with rare deterioration (1.9% of cases), worsening of preoperative diplopia in 49.4% of patients and rarely improving, improvement of trigeminal symptoms in 19.1% of cases (mostly trigeminal neuralgia) among the 43.7% of patients who had them preoperatively, and deterioration of facial hypesthesia and/or paresthesia in 27.4% of cases. Early neurological deterioration was monitored in 183 patients for 6 months to determine the surgical complications of ATPA. Consciousness disturbance recovered in half of the cases but persisted in 3 (1.5%). Hemiparesis fully recovered in 63.2% of cases, resulting in a complication rate of 3.0%. The most frequent complication was diplopia (36.4%), with a complete remission rate of 26.4%. The second most frequent complication was facial hypesthesia (24.0%), with a recovery rate of 16.1%. Facial nerve palsy improved in 63.0% of cases and had a complication rate of 4.9%. Cerebellar symptoms showed complete recovery in all cases.

CONCLUSIONS

The ATPA allows the removal of petroclival tumors extending into Meckel's cave and the middle fossa, making it preferred for dumbbell trigeminal schwannomas and meningiomas. However, the ATPA's aggressive tumor removal can risk a lower recovery of cranial nerve IV-VI deficits. For benign meningiomas, initial observation with regular follow-up is recommended. Surgery is appropriate for high-growth cases aiming for total removal, accompanied by a thorough explanation of the risks. If the risks are not accepted, subtotal removal can be considered, and radiosurgery is suggested for residual tumor.

Anterior Transpetrosal Approach: 2-Dimensional Operative Video

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE

The anterior transpetrosal approach uses the subtemporal corridor to access the Meckel cave and the upper petroclival region from the dorsum sellae down to the cerebellopontine angle.

ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT

The boundaries of posteromedial triangle of the middle fossa must be adequately visualized for the anterior petrosectomy. They are V3 anteriorly, the petrous ridge medially, GSPN laterally, and the meatal plane posteriorly.

ESSENTIALS STEPS OF THE PROCEDURE

The position is supine with the head fully turned. After a temporal craniotomy, the dura is stripped off the floor of the middle fossa. The middle meningeal artery is coagulated and cut, and the greater superficial petrosal nerve is released to allow access to the petrous apex. The extent of the anterior petrosectomy is case-specific, tailored to the exposure needed. The posterior fossa dura is cut where exposed by the petrosectomy and the middle fossa dura just above level of the tentorium and parallel to it. The superior petrosal sinus is ligated and with tentorial incision up to the incisura, the approach is complete.

PITFALLS/AVOIDANCE OF COMPLICATIONS

The contents of the petrous temporal bone, such as the cochlea and labyrinthine, and the point of crossing of the carotid artery under V3 must be examined preoperatively to avoid injury during drilling.

VARIANTS AND INDICATIONS FOR THEIR USE

The anterior transpetrosal approach can be combined with other approaches to expand surgical access. Two examples of this are included in this video.The patients consented to the surgery and to publication of their images.Image at 0:36 from Kawase T, Toya S, Shiobara R, Mine T, Transpetrosal approach for aneurysm of the lower basilar artery, J Neurosurg, 1981;63(6):857-861, with permission from JNSPG; Image at 1:03 from Jean, Skull Base Surgery: Strategies, edition 1 (9781626239579), with permission from Thieme Publishers.

9,9-Bis[4-(N-aryl)phenyl]methylidene-xanthylidene Derivatives Displaying Mechano-, Crystallo-, and Thermochromism

Tetraphenylethylene (TPE) derivatives bearing a xanthene moiety are of interest because they have novel optical properties. 9,9-Bis[4-(N,N-diphenylamino)phenyl] and 9,9-bis[4-(9-carbazolyl)-phenyl]methylidene-xanthylidenes 3 and 4 were synthesized using Suzuki-Miyaura coupling of 9,9-dibromomethylidene-xanthylidene with the corresponding boronic acids. Diphenylamino derivative 3 exhibits mechanochromism and mechanofluorochromism (MC and MFC) reflected in absorption and fluorescence color changes. In contrast, carbazolyl derivative 4 displays thermo- and crystallo-chromism in addition to MC and MFC in the solid state. Powder X-ray diffraction and single crystal X-ray crystallographic analysis reveal that the solid state photophysical properties of these substances are governed by conformational changes rather by the creation of planar π-conjugation extended geometries.

Management of cavernous sinus meningiomas: Consensus statement on behalf of the EANS skull base section

Introduction

The evolution of cavernous sinus meningiomas (CSMs) might be unpredictable and the efficacy of their treatments is challenging due to their indolent evolution, variations and fluctuations of symptoms, heterogeneity of classifications and lack of randomized controlled trials. Here, a dedicated task force provides a consensus statement on the overall management of CSMs.

Research question

To determine the best overall management of CSMs, depending on their clinical presentation, size, and evolution as well as patient characteristics.

Material and methods

Using the PRISMA 2020 guidelines, we included literature from January 2000 to December 2020. A total of 400 abstracts and 77 titles were kept for full-paper screening.

Results

The task force formulated 8 recommendations (Level C evidence). CSMs should be managed by a highly specialized multidisciplinary team. The initial evaluation of patients includes clinical, ophthalmological, endocrinological and radiological assessment. Treatment of CSM should involve experienced skull-base neurosurgeons or neuro-radiosurgeons, radiation oncologists, radiologists, ophthalmologists, and endocrinologists.

Discussion and conclusion

Radiosurgery is preferred as first-line treatment in small, enclosed, pauci-symptomatic lesions/in elderly patients, while large CSMs not amenable to resection or WHO grade II-III are candidates for radiotherapy. Microsurgery is an option in aggressive/rapidly progressing lesions in young patients presenting with oculomotor/visual/endocrinological impairment. Whenever surgery is offered, open cranial approaches are the current standard. There is limited experience reported about endoscopic endonasal approach for CSMs and the main indication is decompression of the cavernous sinus to improve symptoms. Whenever surgery is indicated, the current trend is to offer decompression followed by radiosurgery.

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A thorough evaluation of cavernous sinus meningiomas by a multidisciplinary team is mandatory.

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Microsurgery should be considered for aggressive lesions in young patients.

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Extended endoscopic approaches can be effective when combined with radiotherapy.

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Stereotaxic radiotherapy and stereotaxic radiosurgery offer excellent tumour control in small/asymptomatic lesions .

An isotropic three-dimensional organic semiconductor 2-(thiopyran-4-ylidene)-1,3-benzodithiole (TP-BT): asymmetric molecular design to suppress access resistance

We report the synthesis of P-BT and TP-BT and their OTFT properties based on electronic dimensionality and access resistance (Racc). TP-BT can suppress Racc due to its 3D electronic structure.

Anterior transpetrosal approach: experiences in 274 cases over 33 years. Technical variations, operated patients, and approach-related complications

OBJECTIVE

The anterior transpetrosal approach (ATPA) was initially reported in 1985. The authors' institution has 274 case records of surgery performed with the ATPA during the period from 1984 to 2017. Although many technical advances and modifications in the ATPA have occurred over those 33 years, to the authors' knowledge no articles to date have reported a detailed analysis of variations and complications of the ATPA. In this study, the authors analyzed their patient series to elucidate improvements over time in ATPA methodology while highlighting unresolved problems and evaluating how to avoid surgical complications.

METHODS

All surgical cases (274 patients) using the ATPA at the authors' institution during the period from 1984 to 2017 were analyzed retrospectively using charts, clinical summaries, operative records, and operative videos. Obtained parameters were patient age and sex, diagnosis, size of tumors, location of disease, operative date, neurological symptoms before and after surgery, radiographically identified brain injury, and other surgical complications. The most common diagnosis was petroclival meningioma (n = 158), followed by trigeminal schwannoma (n = 32), chordoma (n = 25), epidermoid tumor (n = 21), other tumor (n = 27), aneurysm (n = 6), and other (n = 5).

RESULTS

The original ATPA was performed in 239 cases. In an additional 35 cases, a modified ATPA was performed. Zygomatic osteotomy with ATPA was a common modification that was used in 19 of the 35 cases to decrease retraction damage to the temporal lobe for high-positioned tumors. Brain injury by temporal lobe retraction without venous hemorrhage still occurred in 8 of the 19 cases (3.1%) with surgical death in 1 of these cases (0.4%) of reoperation with sacrifice of the petrosal vein. Symptomatic CSF leak was the most frequent complication noted and was observed in 35 cases (13.5%). In most of these cases the patients were cured by observation or lumbar drain, but in 6 cases (17.1%) reoperation was needed. Facial nerve damage related to surgical approach decreased from 6.2% to 3.5% after 2010; however, the incidence of CSF leaks (13.5%) has not improved.

CONCLUSIONS

There have been several modifications and advancements made in the ATPA to increase tumor removal and decrease surgical complications. However, complications related to surgical approach occurred, such as venous occlusion-related brain injury and facial nerve damage at pyramid resection. CSF leak remained an unsolved problem related to the ATPA procedures. Preoperative assessment of venous variation of the middle fossa, pneumatization of the temporal bone, and intraoperative monitoring of cranial nerves are important procedures to decrease these complications.

Cell and platelet composition assays by flow cytometry: basis for new platelet-rich fibrin methodologies

Platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) are selective blood fractions obtained by cen¬trifugation. They act locally on inflammation and immunity as adjuvant homeostatic modulators during tissue regeneration. In recent years, many methods for achieving these blood concentrates have emerged, whose parameters of time and force of centrifugation presented themselves as critical, conflicting, and poorly understood points. Thus, the present study aimed to evaluate the effect of different centrifugal experimental parameters on the concentration of cells and platelets in samples of anticoagulated blood. Blood samples were centrifuged by forces of 200, 400 and 800 x g for 5, 10 and 15 minutes of centrifugation times to obtain three fractions: a) platelet-poor plasma (PPP), b) leukocyte-rich plasma (L- PRP) and c) red blood cell sed¬iment (RBC). The leukocyte and platelet content of each centrifuged fraction was measured by automated flow cytometry associated with the peroxidase reaction for differential leukocyte count. The application of 200 x g generated a more significant dispersive content of leukocytes and platelets in the supernatant fraction of PPP when compared to the other two strength ranges. However, it presented the highest concentration of platelets in the sediment (P <0.05 ANOVA), representing a loss of total mass during processing. The 400 and 800 x g forces showed leukocytes and platelets condensed in the L-PRP fraction and lower levels in the sedi¬ment, demonstrating the greater effectiveness of buoyancy in the resuspension of these sedimented elements. Our experimental data showed that the concentration and organization of leukocytes and platelets in the centrifuged blood matrices are very sensitive to variations in g force and centrifugation time, thus generating products with different biological composition and characteristics, and with specific potential therapeutic effects. The present study did not focus on comparing authoring methods, but on presenting the impact of methodological variations on the biological nature of centrifuged blood matrices. Further in vivo studies are needed to assess the specific clinical effect of each methodological change.

Mechano-induced photoluminescence colour change in an alkyltolane-terminated cyanostilbene

A novel alkyltolane-terminated cyanostilbene is synthesized. The photoluminescence colour changed depending on the precipitation method, with either a red shift or blue shift in the photoluminescence spectra observed upon mechanical grinding.

P4760New minimally invasive and tailor-made strategy for cryoballoon ablation in patients with paroxysmal atrial fibrillation

Background

Currently, cryoballoon ablation (CBA) has proven to be highly effective in achieving free from atrial fibrillation (AF), especially paroxysmal AF. However, the optimal freezing protocol for each patient to achieve successful pulmonary vein isolation by only CBA is still uncertain. The aim of this study was to evaluate the clinical implications of a reduction in the freezing duration (<180s) during CBA guided by the time to target temperature.

Methods

From November 2015 to August 2018, 286 consecutive paroxysmal AF patients undergoing CBA were enrolled. We compared 107 patients undergoing a tailor-made CBA procedure (Group A; August 2017-August 2018) to 179 patients with a standard CBA procedure (Group B; November 2015–July 2017). In Group A, the freezing duration was reduced to 150s when the temperature reached ≤−40°C within 40s. Furthermore, we reduced it to 120s when it reached ≤−50°C within 60s. In the other patients, the freezing time was 180s except for excessive freezing over −60°C and/or emergent situations while monitoring the esophageal temperature and for phrenic nerve injury as in Group B.

Results

The baseline clinical characteristics were similar between two groups. In Group A, 89 patients (83%) underwent CBA with a reduction in the freezing time. The rate of having reduction time in left inferior PV (LIPV) and right inferior PV (RIPV) was lower compared with left superior PV (LSPV) and right superior PV (RSPV) (respectively 17%, 29%, 56%, and 63.5%). However, for right inferior PV, in 31 patients having the reduced freezing time, none of them required touch-up ablation. Although the procedure time and frequency of touch-up ablation did not differ between the 2 groups, total freezing time for each PV was significantly shorter in Group A than Group B as shown in figure (LSPV: 164±28s vs. 216±67s; p<0.001, LIPV: 187±44s vs. 218±69s; p<0.001, RSPV: 147±31s vs. 192±51s; p<0.001, RIPV: 180±50 vs. 218±73s; p<0.001). The AF free survival rate during the follow-up period (356±167 days) was similar between the 2 groups (log-rank test, p=0.38). Furthermore, the complication rate was similar 2 groups.

The freezing time for each PV

Conclusion

The safety and efficacy of the new tailor-made CBA strategy were non-inferior to the standard procedure. This study showed that the unnecessary freezing time could be reduced in most of paroxysmal AF patients.

P2694Early and late restenosis after excimer laser coronary angioplasty and paclitaxel-coated balloon combination therapy for drug-eluting stent restenosis

Background

Drug-eluting stent restenosis (DES-ISR) is associated with poorer outcomes than those of bare-metal stent restenosis after treatment with paclitaxel-coated balloon (PCB), and late restenosis after PCB angioplasty for DES-ISR is a residual problem. Excimer laser coronary angioplasty (ELCA) is thought to be advantageous for ISR treatment by removing neointima. However, whether the combination of ELCA and PCB angioplasty is more effective than the use of PCB only angioplasty in DES-ISR has not been studied so far.

Purpose

We evaluated the efficacy of ELCA and PCB combination therapy for DES-ISR at mid-and late-term after revascularization.

Methods

From January 2014 to March 2016, 166 DES-ISR lesions were treated with ELCA and no-ELCA prior to PCB. Two serial angiographic follow-ups were planned for the patients (at 6–12 and 18–24 months after procedure). Acute procedural and follow-up angiographic results were assessed by quantitative coronary angiography. ELCA and no-ELCA group included 74 lesions and 92 lesions, respectively.

Results

There was no significant difference between the two groups in the clinical characteristics except the prevalence of hemodialysis, the rate of first-generation DES (37.9% vs 36.8%, p=0.897), previous stent size (2.90±0.39 mm vs 2.77±0.39 mm, p=0.063), and reference vessel diameter (2.65±0.46 mm vs 2.60±0.65 mm, p=0.593). Early follow-up angiography was performed in 66 lesions (89.1%) of ELCA group, and was done in 76 lesions (82.6%) of no-ELCA group. In the ELCA group, percentage diameter stenosis (%DS) just after procedure and at 6–12 months later were significantly smaller than those of no-ELCA group. Besides, target lesion revascularization (TLR) rate at 6–12 months after procedure was tended to be lower in the ELCA group. Late follow-up angiography was performed for 93 lesions (81.6%) of the remaining 114 lesions (excluding TLR lesion), late restenosis was found 9 lesions (18.6%) in the ELCA group and 11 lesions (24.4%) in the no-ELCA group (p=0.504). Late luminal loss was similar in both groups (0.37±0.71 mm vs 0.24±0.82 mm, p=0.438), and %DS at 12–18 months after revascularization was not different between the two groups.

Changes of %DS and TLR rate

Conclusions

%DS in the ELCA group was smaller at just after procedure and the advantage was kept even after 1-year. However, late restenosis and TLR at 2-year after revascularization for DES-ISR could not be reduced by ELCA and PCB combination therapy.

Staged deep brain stimulation of ventral intermediate nucleus of the thalamus for suppression of essential tremors

Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus is a powerful surgical option in the treatment of essential tremors (ETs). However, its therapeutic efficacy depends on the tremor distribution. DBS is highly efficient in the relief of distal appendicular tremor but not other types of tremor. We report a case of staged DBS of ventral intermediate nucleus (VIM) of thalamus for the suppression of ETs.

Combined Endovascular and Microsurgical Hybrid Management of Cerebral Aneurysms: The Preliminary Fujita Experience

Introduction:

A subgroup of complex aneurysms demands multimodal treatment by microscopic and endovascular means. Partial obliteration or remnant postprocedure demands to go further to the other modality.

Materials and Methods:

All patients between July 2016 and January 2017 who had to undergo multimodality measures for complete obliteration of the aneurysms were included in the study. The patients who had either undergone clipping or coiling for their aneurysms, but with incomplete obliteration of the aneurysm, were also included in the study.

Results:

Between July 2016 and January 2017, a total of three patients had to undergo coiling after clipping of the aneurysm for complete obliteration. Two patients had to go for clipping following coiling. All five patients had complete obliteration of the aneurysm sac.

Conclusion:

Both microscopic and endovascular means are complementary measures instead of competing procedures. It is important to realize the technical difficulties when surgical therapy follows initial endovascular treatment. Similarly, coiling a previously clipped aneurysm can be difficult, if the clip obscures normal working projections.

Effects of Surgery and Radiotherapy on Recurrent Skull Base Meningiomas: Clinical and Biological Analyses

We reviewed the medical records of 392 patients who underwent initial surgery for skull base meningiomas between 1983 and 2008. Among them, 32 (8.2%) showed tumor recurrence. Risk factors for recurrence were analyzed clinically and biologically. Recurrent cases were treated with radiotherapy, surgery, or both. In reoperation cases, pathological and biological changes were analyzed and compared between groups with or without radiotherapy. The recurrence rate was statistically high in cases of partial tumor removal and in patients with tumor in the cavernous sinus, tumors with histological WHO (World Health Organization) grade ≥ II or MIB-1 index > 3. The local control rate of postoperative radiotherapy for recurrent cases was 66.7%. Malignant transformation and MIB-1 index elevation was observed more frequently in patients who underwent reoperation after radiotherapy than in the reoperation-only group. Risk factors for recurrence of skull base meningiomas are as follows: (1) partial tumor removal, (2) tumor in the cavernous sinus, (3) histological WHO grade ≥ II, or (4) MIB-1 index > 3. Postoperative radiotherapy might be effective for tumor recurrence. However, the indications for radiotherapy should be carefully considered because postsurgical radiotherapy may increase biological activity, inducing malignant transformation.

Grafted Miniature-Swine Neural Stem Cells of Early Embryonic Mesencephalic Neuroepithelial Origin can Repair the Damaged Neural Circuitry of Parkinson's Disease Model Rats

Although recent progress in the use of human iPS cell-derived midbrain dopaminergic progenitors is remarkable, alternatives are essential in the strategies of treatment of basal-ganglia-related diseases. Attention has been focused on neural stem cells (NSCs) as one of the possible candidates of donor material for neural transplantation, because of their multipotency and self-renewal characteristics. In the present study, miniature-swine (mini-swine) mesencephalic neuroepithelial stem cells (M-NESCs) of embryonic 17 and 18 days grafted in the parkinsonian rat striatum were assessed immunohistochemically, behaviorally and electrophysiologically to confirm their feasibility for the neural xenografting as a donor material. Grafted mini-swine M-NESCs survived in parkinsonian rat striatum at 8 weeks after transplantation and many of them differentiated into tyrosine hydroxylase (TH)-positive cells. The parkinsonian model rats grafted with mini-swine M-NESCs exhibited a functional recovery from their parkinsonian behavioral defects. The majority of donor-derived TH-positive cells exhibited a matured morphology at 8 weeks. Whole-cell recordings from donor-derived neurons in the host rat brain slices incorporating the graft revealed the presence of multiple types of neurons including dopaminergic. Glutamatergic and GABAergic post-synaptic currents were evoked in the donor-derived cells by stimulation of the host site, suggesting they receive both excitatory and inhibitory synaptic inputs from host area. The present study shows that non-rodent mammalian M-NESCs can differentiate into functionally active neurons in the diseased xenogeneic environment and could improve the parkinsonian behavioral defects over the species. Neuroepithelial stem cells could be an attractive candidate as a source of donor material for neural transplantation.

Study of predisposing risk factors and etiology of chronic subdural hematoma in clipped patients of unruptured intracranial aneurysms – an institutional experience

Introduction: Chronic subdural hematoma in clipped patients of unruptured intracranial aneurysms might lead to sudden neurological deterioration and may need emergency evacuation. We studied the effects of various factors in its etiology. Materials and methods: A retrospective study of 91operated clipped patients of unruptured aneurysms in the year 2014-2015 was taken. Various predisposing factors were studied. Results: Goreisan use was not associated with any reduction in post operative CSDH formation. Arachnoidoplasty and reduced post operative dead space contributed in a reduced formation of CSDH. Conclusion: Older male patients with aneurysms who had been treated with anticoagulant drugs should be considered candidates for additive ARP to prevent the development of postoperative CSDH.

Bicyclo[6.3.0]undeca-1(11),2,4,6,8-pentaen-10-ylidene: An Aromatic Carbene with Ambiphilic Properties

The title carbene (4) was generated as a highly reactive species in solution by photoirradiation of 10-diazobicyclo[6.3.0]undecapentaene (5) using a high-pressure mercury lamp. Carbene 4 reacts with benzene to afford two isomeric adducts, 10-phenylbicyclo[6.3.0]undecapentaene (10) and tricyclo[9.3.0^3, 10 .0]heptadeca-1,3(10),4,6,8,12,14,16-octaene (11). The reactivity toward benzene is a characteristic of an electrophilic aromatic carbene analogous to cyclopentadienylidene 1. In contrast, the reaction of 4 with methanol produces 7-methoxybicyclo[6.3.0]undeca-1,3,5,8,10-pentaene (15). When [D₁ ]methanol was employed as a reactant, the 10-deuterated analogue was formed. The results clearly indicate the formation of bicyclo[6.3.0]undecapentaenyl cation (7) as a novel 10 π-electronic compound by protonation of 4. Theoretical calculations indicate that the 2- and 7-positions of the cation have the largest positive charge in the cation. Moreover, the carbene was generated in the presence of tert-butyl hydroperoxide in aqueous tetrahydrofuran to afford azulene through oxidation of 7, followed by decarbonylation. The nucleophilic property of carbene 3 is similar to that of cycloheptatrienylidene 2. Thus, 4 can be regarded as a novel ambiphilic aromatic carbene.

Vigorous Neuronal Differentiation of Amplified and Grafted Basic Fibroblast Growth Factor-Responsive Neurospheres Derived from Neuroepithelial Stem Cells

Neuroepithelial stem cells (NESCs) have emerged as a possible donor material aimed at neural transplantation for the repair of damaged neural circuitry, particularly because of their propensity to differentiate into neurons. We previously ascertained in vitro that NESCs derived from rat early embryos could be amplified in culture containing basic fibroblast growth factors (bFGF), and that neurospheres grown for 7 days in the culture had a strong tendency to differentiate into neurons. In this report, we analyze immunohistochemically the biological nature of bFGF-responsive neurospheres derived from NESCs. We first succeeded in amplifying the number of NESCs from the mesencephalic neural plate of embryonic day 10 Wistar rats with the addition of bFGF. Grown neurospheres were labeled with bromodeoxyuridine (BrdU) in vitro and were stereotactically transplanted into the right striatum of the normal adult Wistar rat. Two weeks after transplantation, a viable graft in the host brain was observed. While many BrdU/Hu double positive cells were seen in the graft, and a few BrdU/nestin double positive cells were also seen, no BrdU/GFAP double positive cells could be identified. These results suggested that bFGF-responsive neurospheres derived from NESCs demonstrated a propensity to differentiate into neurons in the adult brain environment. Furthermore, following in vitro amplification of the original stem cell number with bFGF, the grown neurospheres preserved their propensity to differentiate vigorously into neurons. NESCs are thus suggested as a feasible candidate for intracerebral grafting donor materials aimed at reconstruction of damaged neural circuits.

Implantation of Xenogeneic Transgenic Neural Plate Tissues into Parkinsonian Rat Brain

Xenografting must be considered as a means of establishing neural transplantation therapy and of securing fetal neural tissues as donor material. The early stage (embryonic day 8.5, E8.5) embryonic mesencephalic neural plate (NP) from transgenic mice was examined for possible application in effective xenografting therapy. As recipients, Parkinsonian rats treated with 6-hydroxydopamine were used, and as donors, GT4-2 mice into which a β-galactosidase gene was introduced to allow brain tissue differentiation from the recipients by X-gal staining. Three microscopic pieces of E8.5 GT4-2 mice NP were injected into the striatum of the Parkinsonian rats. Some hosts were given immunosuppressants (cyclophosphamide and FK506) (IS group), others were not (non-IS group). Amphetamine-induced rotation was examined at days 11 and 21 after grafting (D11 and D21, respectively), and morphological investigations were performed using hematoxylin-eosin (H-E), X-gal, and thyrosine hydroxylase (TH) staining. The rotations were counted in 30 of the 38 transplanted rats before and after grafting. Histological data were obtained from 19 of these 30 rats. In 11 of them the grafts survived (survival group) and in the remaining 8, the grafts were unsuccessful (rejection group). In the survival group at D11, the mean number of rotations made by transplanted rats expressed as a percentage of the number before grafting (rotation percentage) decreased to 43.8% (n = 9), which, in comparison with the average of 125.9% (n = 6) in the rejection group, reveals significant behavioral recovery (p < 0.01). The rotation percentage at D21 was 23.8% in the survival group (n = 4) and 84.5% in the rejection group (n = 3). Behavioral recovery was thus seen to improve with time in the survival group. In the IS group (n = 19), the rotation percentages averaged 74.9% (D11, n = 15) and 51.1% (D21, n = 7), while the non-IS group averages were 136.7% (D11, n = 9) and 140.7% (D21, n = 9), indicating a tendency for better behavioral recovery in the IS group than in the non-IS group (p < 0.05). Fifteen IS group rats were studied histologically, 10 (sacrificed on D11, D21) from the survival group and 5 (sacrificed on D11, D21) from the rejection group. In the non-IS group (n = 4), there was a graft in only one rat sacrificed on D11. There were many X-gal positive and TH positive cells in the grafts, suggesting that mouse NP survived, and differentiated into TH positive neurons in the rat brain. Xenografted NP has the potential to cure central nervous system diseases.

Feasibility of Using Early Mesencephalic Neural Plate for Intracerebral Grafting

The purpose of this study was to elucidate the biological significance and the possibility of intracerebral grafting of neuroepithelial stem cells derived from the mesencephalic neural plate. Immunohistological studies of embryonic day 10.5 (E10.5) Wister rats revealed strong nestin expression in the mesencephalic part of the neural plate. Mesencephalic neural plates removed from E10.5 rats were processed to either tissue or cell dissociation culture. They were cultured in vitro under various conditions and were analyzed 7 days after the primary culture. When they were cultured as a tissue, cell proliferation and differentiation into neurons extending long neurites were obvious in a serum-free medium, in a medium containing 3% serum, and in a medium containing 20 ng/ml epidermal growth factor. On the other hand, in a medium containing 10 ng/ml basic fibroblast growth factor (bFGF), both vigorous cell proliferation and sphere formation were recognized. Furthermore, marked neurite growth was rarely seen in this culture. When they were plated in a dissociation culture, cell proliferation and neurosphere generation were also recognized only in a medium containing bFGF, depending on the initial cell concentration. The spheres, generated 7 days after the primary cell culture, were positively stained by nestin. These data suggested that bFGF was able to amplify the stem cell population present in the mesencephalic neural plate derived from early embryos. This might make it possible to obtain a large number of stem cells as donor material for neural transplantation on demand.

π-Extended fluoranthene imide derivatives: synthesis, structures, and electronic and optical properties

Diels–Alder reactions of acenaphthylene-5,6-dicarboximide (AI) derivatives with the corresponding dienes afforded some derivatives of π-extended fluoranthene imide, namely N-(2-ethylhexyl)-7,10-diphenylfluoranthene imide (DPFI) and N-(2-ethylhexyl)-7,8,9,10-tetraphenylfluoranthene imide (TPFI), N-(n-octyl)-benzo[k]fluoranthene imide (BFI), and N-(n-octyl)-naphtho[k]fluoranthene imide (NFI). Molecular structures of TPFI and BFI reveal that the core π-skeletons have a highly planar structure, and the molecules form a dimeric structure in the crystals. The absorption spectra exhibit bathochromic shift with π-extension of the core π-skeletons. On the other hand, DPFI and TPFI show the long-wavelength emission related to BFI, probably due to π-extension toward the phenyl substituents in the excited states. BFI and NFI exhibited an interesting concentration-dependent 1H-NMR behavior in CDCl3, suggesting self-aggregation formation. Moreover, BFI and NFI show moderate and remarkable solvatofluorochromism in solutions (BFI for ΔλEM = 67 nm, NFI for ΔλEM = 116 nm), respectively, while DPFI and TPFI show weak solvatofluorochromism. The density functional theory calculations demonstrate that the considerable spatial separation between the HOMO and LUMO coefficients in the NFI molecule. The result indicates that the ground-to-excited state transition of NFI should have intramolecular charge transfer (ICT) character.

A new fluorophore displaying remarkable solvatofluorochromism and solid-state light emission, and serving as a turn-on fluorescent sensor for cyanide ions

A new fluorophore displays remarkable solvatofluorochromism, a CIEE effect, and an intense blue-green fluorescence in the presence of cyanide ions.

Reversibility of energy metabolism and intracellular pH after cerebral ischaemia evaluated by 31P-MRS

We have previously developed a reproducible model of transient forebrain ischaemia in rats by bilateral carotid artery occlusion combined with temporary increase of ICP. With this model, reversibility of the energy metabolism and intracellular pH (pHi) was investigated by 31P-MRS during 120 min of recirculation in three groups of, respectively, 30, 60, and 120 min of ischaemia. With the induction of ischaemia, ATP and phosphocreatine (PCr) disappeared, and measurement of pHi showed severe acidosis in all rats. In the 30 min ischaemia group, both energy metabolism and pHi recovered almost completely. In the 60 min ischaemia group, ATP recovered to 74% of control values, but pHi showed full recovery. In the 120 min ischaemia group, ATP recovered to about 50% of control values, and recovery of pHi was variable. Showing logarithmical changes during recirculation in ATP and PCr, the rate of metabolic recovery was fast during 60 min of recirculation, but it decreased and reached plateau thereafter in all groups. Recovery of pHi was affected by ATP levels, and was precipitously accelerated as ATP levels exceeded 50% of pre-ischaemic values. These results suggest that prolongation of the duration of ischaemia limits the restoration of the energy state, and the quality of pHi recovery after cerebral ischaemia is affected by the degree of ATP recovery during 60 min of recirculation.

2,7,10,13-Tetra-tert-butyl-N-phenylacenaphtho[1,2-j]fluoranthene-4,5-dicarboximide

In the molecule of the title compound, C50H49NO2, the acenaphtho[1,2-j]fluoranthene-4,5-dicarboximide framework has an approximately planar structure [maximum deviation = 0.124 (3) Å] and subtends a dihedral angle of 62.94 (8)° with the pendant phenyl group. Two of thetert-butyl groups are disordered over two sets of sites, with occupancy ratios of 0.506 (8):0.494 (8) and 0.669 (17):0.331 (17). An intermolecular short contact between a methyl group and the aromatic ring occurs in the crystal structure.

MIF Maintains the Tumorigenic Capacity of Brain Tumor-Initiating Cells by Directly Inhibiting p53

Tumor-initiating cells thought to drive brain cancer are embedded in a complex heterogeneous histology. In this study, we isolated primary cells from 21 human brain tumor specimens to establish cell lines with high tumorigenic potential and to identify the molecules enabling this capability. The morphology, sphere-forming ability upon expansion, and differentiation potential of all cell lines were indistinguishable in vitro However, testing for tumorigenicity revealed two distinct cell types, brain tumor-initiating cells (BTIC) and non-BTIC. We found that macrophage migration inhibitory factor (MIF) was highly expressed in BTIC compared with non-BTIC. MIF bound directly to both wild-type and mutant p53 but regulated p53-dependent cell growth by different mechanisms, depending on glioma cell line and p53 status. MIF physically interacted with wild-type p53 in the nucleus and inhibited its transcription-dependent functions. In contrast, MIF bound to mutant p53 in the cytoplasm and abrogated transcription-independent induction of apoptosis. Furthermore, MIF knockdown inhibited BTIC-induced tumor formation in a mouse xenograft model, leading to increased overall survival. Collectively, our findings suggest that MIF regulates BTIC function through direct, intracellular inhibition of p53, shedding light on the molecular mechanisms underlying the tumorigenicity of certain malignant brain cells. Cancer Res; 76(9); 2813-23. ©2016 AACR.

Comparative analysis of the anterior transpetrosal approach with the endoscopic endonasal approach to the petroclival region

OBJECTIVE The endoscopic endonasal approach (EEA) offers direct access to midline skull base lesions, and the anterior transpetrosal approach (ATPA) stands out as a method for granting entry into the upper and middle clival areas. This study evaluated the feasibility of performing EEA for tumors located in the petroclival region in comparison with ATPA. METHODS On 8 embalmed cadaver heads, EEA to the petroclival region was performed utilizing a 4-mm endoscope with either 0° or 30° lenses, and an ATPA was performed under microscopic visualization. A comparison was executed based on measurements of 5 heads (10 sides). Case illustrations were utilized to demonstrate the advantages and disadvantages of EEA and ATPA when dealing with petroclival conditions. RESULTS Extradurally, EEA allows direct access to the medial petrous apex, which is limited by the petrous and paraclival internal carotid artery (ICA) segments laterally. The ATPA offers direct access to the petrous apex, which is blocked by the petrous ICA and abducens nerve inferiorly. Intradurally, the EEA allows a direct view of the areas medial to the cisternal segment of cranial nerve VI with limited lateral exposure. ATPA offers excellent access to the cistern between cranial nerves III and VIII. The quantitative analysis demonstrated that the EEA corridor could be expanded laterally with an angled drill up to 1.8 times wider than the bone window between both paraclival ICA segments. CONCLUSIONS The midline, horizontal line of the petrous ICA segment, paraclival ICA segment, and the abducens nerve are the main landmarks used to decide which approach to the petroclival region to select. The EEA is superior to the ATPA for accessing lesions medial or caudal to the abducens nerve, such as chordomas, chondrosarcomas, and midclival meningiomas. The ATPA is superior to lesions located posterior and/or lateral to the paraclival ICA segment and lesions with extension to the middle fossa and/or infratemporal fossa. The EEA and ATPA are complementary and can be used independently or in combination with each other in order to approach complex petroclival lesions.