Tunable thermal diffusivity of silk protein assemblies based on their structural control and photo-induced chemical cross-linking.

Silk, which has excellent mechanical properties and is lightweight, serves as a structural material in natural systems. However, the structural and functional applications of silk in artificial systems have been limited due to the difficulty in controlling its properties. In this study, we demonstrate the tunable thermal diffusivity of silk-based assemblies (films) based on secondary structural control and subsequent cross-linking. We found that the thermal diffusivity of the silk film is increased by the formation of ß-sheet structures and dityrosine between Tyr residues adjacent to the ß-sheet structures. Our results demonstrate the applicability of silk proteins as material components for thermally conductive biopolymer-based materials.

Spinal dural and epidural fistulas: role of cone beam CT in diagnosis and treatment.

Understanding normal spinal arterial and venous anatomy, and spinal vascular disease, is impossible without flow-based methods. Development of practical spinal angiography led to site-specific categorization of spinal vascular conditions, defined by the 'seat of disease' in relation to the cord and its covers. This enabled identification of targets for highly successful surgical and endovascular treatments, and guided interpretation of later cross-sectional imaging.Spinal dural and epidural arteriovenous fistulas represent the most common types of spinal shunts. Although etiology is debated, anatomy provides excellent pathophysiologic correlation. A spectrum of fistulas, from foramen magnum to the sacrum, is now well-characterized.Most recently, use of cone beam CT angiography has yielded new insights into normal and pathologic anatomy, including venous outflow. It provides unrivaled visualization of the fistula and its relationship with spinal cord vessels, and is the first practical method to study normal and pathologic spinal veins in vivo-with multiple implications for both safety and efficacy of treatments. We advocate consistent use of cone beam CT imaging in modern spinal fistula evaluation.The role of open surgery is likely to remain undiminished, with increasing availability and use of hybrid operating rooms for practical intraoperative angiography enhancing safety and efficacy of complex surgery.

Clinical Significance of Early Venous Filling Detected via Preoperative Angiography in Glioblastoma.

Preoperative angiography in glioblastoma (GBM) often shows arteriovenous shunts and early venous filling (EVF). Here, we investigated the clinical implications of EVF in GBM as a prognostic and vascular mimicry biomarker. In this retrospective multicenter study, we consecutively enrolled patients who underwent angiography with a GBM diagnosis between 1 April 2013 and 31 March 2021. The primary and secondary endpoints were the differences in overall survival (OS) and progression-free survival (PFS), respectively, between cases with and without EVF. Of the 133 initially enrolled patients, 91 newly diagnosed with GBM underwent preoperative angiography and became the study population. The 6-year OS and PFS were significantly worse in the EVF than in the non-EVF group. Moreover, 20 GBM cases (10 with EVF and 10 without EVF) were randomly selected and evaluated for histological vascular mimicry. Except for two cases that were difficult to evaluate, the EVF group had a significantly higher frequency of vascular mimicry than the non-EVF group (0/8 vs. 5/10, p = 0.04). EVF on preoperative angiography is a robust prognostic biomarker for GBM and may help detect cases with a high frequency of histological vascular mimicry.

Association Between Cerebral Angiography and Asymmetrical Cortical and Deep/Medullary Vein Signs on T2 Star Magnetic Resonance Imaging in Patients with Hyperacute Horizontal Segment of the Middle Cerebral Artery Occlusion.

BACKGROUND: When treating acute ischemic stroke patients, evaluation of collateral flow to the ischemic area is essential. Blood-oxygen-level-dependent imaging, including T2 star (T2∗), can identify elevated deoxyhemoglobin levels, reflecting an increase in the oxygen extraction fraction. Prominent veins on T2∗ represent increased deoxyhemoglobin and cerebral blood volume. This study compared asymmetrical vein signs (AVSs) on T2∗ and digital subtraction angiography findings during mechanical thrombectomy (MT) in patients with hyperacute middle cerebral artery occlusion. METHODS: Clinical and imaging data of 41 patients with occlusion of the horizontal segment of the middle cerebral artery who underwent MT were collected. Patients were divided into 2 groups based on angiographic occlusion sites as: proximal and distal to the lenticulostriate artery (LSA). AVSs on T2∗ were divided into asymmetrical cortical vein sign (cortical AVS) and asymmetrical deep/medullary vein sign (deep/medullary AVS), and were compared with the findings of intraoperative digital subtraction angiography. RESULTS: Twenty-seven patients had AVSs. Cortical AVS was the only parameter with a significant association with poor angiographic collateral supply. In terms of occlusion site, deep/medullary AVS was the only parameter with a significant association with occlusion proximal to the LSA. CONCLUSIONS: In patients with occlusion of the horizontal segment of the middle cerebral artery, presence of the cortical AVS on T2∗ suggests a poor angiographic collateral supply, while presence of the deep/medullary AVS suggests impaired blood flow to the basal ganglia through LSAs. Both these signs contribute to poor outcomes in patients undergoing MT.

World federation of interventional and therapeutic neuroradiology (WFITN) federation assembly neurointerventional surgery safety checklist.

Over the last 10 years, there has been a rise in neurointerventional case complexity, device variety and physician distractions. Even among experienced physicians, this trend challenges our memory and concentration, making it more difficult to remember safety principles and their implications. Checklists are regarded by some as a redundant exercise that wastes time, or as an attack on physician autonomy. However, given the increasing case and disease complexity along with the number of distractions, it is even more important now to have a compelling reminder of safety principles that preserve habits that are susceptible to being overlooked because they seem mundane. Most hospitals have mandated a pre-procedure neurointerventional time-out checklist, but often it ends up being done in a cursory fashion for the primary purpose of 'checking off boxes'. There may be value in iterating the checklist to further emphasize safety and communication. The Federation Assembly of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) decided to construct a checklist for neurointerventional cases based on a review of the literature and insights from an expert panel.

Fatal hemorrhagic complication after coil embolization of a petrosal arteriovenous shunt.

BACKGROUND: Cerebello-pontine AVMs (CPAVMs) and petrous apex dural arteriovenous fistulae (DAVFs) are rare and sometimes difficult to distinguish. We report a fatal hemorrhagic complication after coil embolization of the petrosal vein draining a trigeminal AVM misdiagnosed as a DAVF. CASE PRESENTATION: A 73-year-old woman with a petrous apex arteriovenous shunt with dual dural and pial arterial supply presented with posterior fossa hemorrhage. The draining petrosal vein was catheterized and coiled via the superior petrosal sinus. Two episodes of contrast extravasation occurred during coiling, but the lesion was completely occluded at the end of the procedure. The patient developed a fatal posterior fossa hemorrhage in the recovery room. Microscopic pathology revealed numerous dilated vessels within the trigeminal nerve. CONCLUSION: CPAVMs and DAVFs with pial drainage should be distinguished pre-operatively. Occlusion of a pial vein (as opposed to a sinus) in the treatment of an arteriovenous shunt carries hemorrhagic risk if a liquid embolic agent is not used to completely occlude all pathological vessels.

Personal effects of the SARS-CoV-2 pandemic in Japan: The toughest triage.

The Japan healthcare system is considered as one of the world's finest. However, medical facilities across Japan are struggling to cope with the recent surge in novel coronavirus infections, leaving the medical care system in many areas on the brink of collapse. Physician burnout was already a growing problem, and the coronavirus disease 2019 pandemic has only made it worse. The personal impact of coronavirus disease 2019 in Japan is reported.

Transition of chemical management in Japan -Shift to self-regulation and measures for small businesses.

Increased variety and use of chemicals and the number of chemical disasters have changed chemical management. Europe and the United States have adopted self-regulation in chemical management; furthermore, countries worldwide must comply with the relevant United Nations recommendations and international standards for chemical management. Japan has experienced numerous pollution incidents and occupational disasters, resulting in the development of laws and regulations on chemical management; however, these policies are inconsistent with international trends. In particular, the shift from a compliance approach to self-regulation and measures for small businesses remain as challenges. This paper discusses the current situation and issues in chemical management in Japan, focusing on international trends.

When Is Diagnostic Subtraction Angiography Indicated Before Clipping of Unruptured and Ruptured Intracranial Aneurysms? An International Survey of Current Practice.

INTRODUCTION: The goal of this survey is to investigate the indications for preoperative digital subtraction angiography (DSA) before clipping of ruptured and unruptured intracranial aneurysms in an international panel of neurovascular specialists. METHODS: An anonymous survey of 23 multiple-choice questions relating to indications for DSA before clipping of an intracranial aneurysm was distributed to the international panel of attendees of the European-Japanese Cerebrovascular Congress (EJCVC), which took place in Milan, Italy on 7-9 June 2018. The survey was collected during the same conference. Descriptive statistics were used to analyze the data. RESULTS: A total of 93 surveys were distributed, and 67 (72%) completed surveys were returned by responders from 13 different countries. Eighty-five percent of all responders were neurosurgeons. For unruptured and ruptured middle cerebral artery (MCA) aneurysms without life-threatening hematoma, approximately 60% of responders perform surgery without preoperative DSA. For aneurysms in other locations than MCA, microsurgery is done without preoperative DSA in 68% of unruptured and in 73% of ruptured cases. In cases of ruptured MCA or ruptured non-MCA aneurysms with life-threatening hematoma, surgery is performed without DSA in 97% and 96% of patients, respectively. Factors which lead to preoperative DSA being performed were: aneurysmal shape (fusiform, dissecting), etiology (infectious), size (>25 mm), possible presence of perforators or efferent vessels arising from the aneurysm, intra-aneurysmal thrombus, previous treatment, location (posterior circulation and paraclinoid aneurysm) and flow-replacement bypass contemplated for final aneurysm treatment. These are all factors that qualify an aneurysm as a complex aneurysm. CONCLUSION: There is still a high variability in the surgeons' preoperative workup regarding the indication for DSA before clipping of ruptured and unruptured intracranial aneurysms, except for ruptured aneurysms with life-threatening hematoma. There is a general consensus among cerebrovascular specialists that any angioanatomical feature indicating a complex aneurysm should lead to a more detailed workup including preoperative DSA.

Spinal Dural AVFs: Classifications and Advanced Imaging.

Spinal dural arteriovenous fistulas (SDAVFs) are the most common vascular shunts of the spine. They occur predominantly in men (more than 80%), commonly involve the thoracolumbar spine, and usually cause progressive myelopathy because of venous congestion of the spinal cord. Recent advanced imaging technology can visualize the detailed angioarchitecture of the spinal cord, and this provides more information of the regional microanatomy related with the shunt disease. We retrospectively analyzed the location of the shunt with adjacent vasculatures and assessed the efficacy and the sensitivity of each imaging modality. Based on these data, a new concept of classification for SDAVFs was reviewed.

Associations of pathological diagnosis and genetic abnormalities in meningiomas with the embryological origins of the meninges.

Certain driver mutations and pathological diagnoses are associated with the anatomical site of meningioma, based on which the meninges have different embryological origins. We hypothesized that mutations and pathological diagnoses of meningiomas are associated with different embryological origins. We comprehensively evaluated associations among tumor location, pathological diagnosis (histological type), and genetic alterations including AKT1, KLF4, SMO, POLR2A, and NF2 mutations and 22q deletion in 269 meningioma cases. Based on the embryological origin of meninges, the tumor locations were as follows: neural crest, paraxial mesodermal, and dorsal mesodermal origins. Tumors originating from the dura of certain embryologic origin displayed a significantly different pathological diagnoses and genetic abnormality ratio. For instance, driver genetic mutations with AKT1, KLF4, SMO, and POLR2A, were significantly associated with the paraxial mesodermal origin (p = 1.7 × 10-10). However, meningiomas with NF2-associated mutations were significantly associated with neural crest origin (p = 3.9 × 10-12). On analysis of recurrence, no difference was observed in embryological origin. However, POLR2A mutation was a risk factor for the tumor recurrence (p = 1.7 × 10-2, Hazard Ratio 4.08, 95% Confidence Interval 1.28-13.0). Assessment of the embryological origin of the meninges may provide novel insights into the pathomechanism of meningiomas.

Intrapartum Subarachnoid Hemorrhage from Suspected Lateral Posterior Choroidal Artery Dissection.

Stroke associated with pregnancy or puerperium is rare, but represents an important problem for women of childbearing age. We herein report a case of subarachnoid hemorrhage (SAH) due to suspected lateral posterior choroidal artery (LPChA) dissection during delivery. A 34-year-old woman developed deterioration of consciousness during delivery at a maternity clinic. Her Glasgow Coma Scale score was E3V3M6. She was sent to our hospital after 12 hr, where CT revealed SAH with intraventricular hematoma. Radiographic examinations showed contrast pooling on the left LPChA. Repeated angiography showed enlargement of the contrast pooling, which indicated pseudoaneurysm. It also showed a relatively clear but stenosed LPChA communicated with the lesion which could not be recognized in the angiography on day 0. This stenosed LPChA indicated arterial dissection. Therefore, endovascular parent artery occlusion was performed on day 11. Determining the exact extent of dissection was difficult because the LPChA was extremely narrow. Occlusion of the posterior cerebral artery was needed to achieve complete hemostasis, which, however, resulted in infarction of the medial temporal and occipital lobes. At the time of final follow-up 3 years later, the patient was alert and completely independent, but showed persistent incomplete homonymous hemianopsia. We reported a rare case of SAH from suspected LPChA dissection during delivery. Repeated angiography provided information about the source of hemorrhage and definite diagnosis, which opened the way to treatment. It is also important to recognize the difficulty in identifying the exact extent of dissection when treating dissections of small arteries.

Discovery of Surfactant-Like Peptides from a Phage-Displayed Peptide Library.

Peptides with specific affinities for various materials have been identified in the past three decades and utilized in materials science and engineering. A peptide's capability to specifically interact with materials is not naturally derived but screened from a biologically constructed peptide library displayed on phages or cells. To date, due to limitations in the screening procedure, the function of screened peptides has been primarily limited to the affinity for target materials. Herein, we demonstrated the screening of surfactant-like peptides from a phage-displayed peptide library. A screened phage clone displaying a peptide showed high activity for accumulating at emulsion surfaces with certain assembled structures, resulting in stable emulsions. The surface tension for the solution of the chemically synthesized peptide decreased with increasing peptide concentration, demonstrating certain surface activity, which corresponded to the ability to decrease the surface tension of liquids (e.g., water), owing to the accumulation of molecules at the air-liquid or liquid-liquid interface. Peptides with a randomized sequence did not lower the surface tension, indicating the essential role of amino acid sequences in surface activity. Our strategy for identifying novel functional peptides from a phage-displayed peptide library can be used to expand the applicability of peptidyl materials and biosurfactants.

COVID-19 and neurointerventional service worldwide: a survey of the European Society of Minimally Invasive Neurological Therapy (ESMINT), the Society of NeuroInterventional Surgery (SNIS), the Sociedad Iberolatinoamericana de Neuroradiologia Diagnostica y Terapeutica (SILAN), the Society of Vascular and Interventional Neurology (SVIN), and the World Federation of Interventional and Therapeutic Neuroradiology (WFITN).

BACKGROUND: This survey was focused on the provision of neurointerventional services, the current practices of managing patients under COVID-19 conditions, and the expectations for the future. METHODS: Invitations for this survey were sent out as a collaborative effort of the European Society of Minimally Invasive Neurological Therapy (ESMINT), the Society of NeuroInterventional Surgery (SNIS), the Sociedad Iberolatinoamericana de Neuroradiologia Diagnostica y Terapeutica (SILAN), the Society of Vascular and Interventional Neurology (SVIN), and the World Federation of Interventional and Therapeutic Neuroradiology (WFITN). RESULTS: Overall, 475 participants from 61 countries responded (six from Africa (1%), 81 from Asia (17%), 156 from Europe (33%), 53 from Latin America (11%), and 172 from North America (11%)). The majority of participants (96%) reported being able to provide emergency services, though 26% of these reported limited resources. A decrease in emergency procedures was reported by 69% of participants (52% in ischemic and hemorrhagic stroke, 11% ischemic, and 6% hemorrhagic stroke alone). Only 4% reported an increase in emergency cases. The emerging need for social distancing and the rapid adoption of remote communication was reflected in the interest in establishing case discussion forums (43%), general online forums (37%), and access to angio video streaming for live mentoring and support (33%). CONCLUSION: Neurointerventional emergency services are available in almost all centers, while the number of emergency patients is markedly decreased. Half of the participants have abandoned neurointerventions in non-emergent situations. There are considerable variations in the management of neurointerventions and in the expectations for the future.

[Preoperative Embolization for Organized Hematoma of the Maxillary Sinus with Low-concentration n-butyl-2-cyanoacrylate:A Case Report].

Organized hematoma is a rare, non-neoplastic, and hemorrhage-prone condition that requires attention due to the risk of intraoperative bleeding. Preoperative embolization was performed to ensure intraoperative hemorrhage control. Here, we report a case of preoperative embolization of an organized hematoma using a low-concentration of n-butyl-2-cyanoacrylate(NBCA). An 80-year-old male presented with a 2-month history of repeated nasal bleeding and nasal obstruction. Diagnostic imaging revealed a mass measuring 3.7 cm in the right maxillary sinus with thinning of the surrounding bone. This was diagnosed as an organized hematoma with a biopsy. As a preoperative treatment, embolization of the main feeding artery was performed through the external carotid artery, using a low concentration of NBCA(5%). When the NBCA cast had reached the organized hematoma, as observed on plain CT, endoscopic sinus surgery was performed, and the organized hematoma was resected without significant bleeding. Preoperative embolization of the organized hematoma with low-concentration NBCA was useful to prevent heavy intraoperative bleeding.

Controlled assembly of filamentous viruses into hierarchical nano- to microstructures at liquid/liquid interfaces.

Recently, viruses have been regarded as useful molecular assemblies for materials applications rather than as disease-causing agents. The orderly assembled structures of the viruses are highly related to the resultant properties and functions of the assemblies; however, methods to control the assembly are still limited. Here, we demonstrated the assembly of filamentous viruses into hierarchical nano- to microstructures at liquid/liquid interfaces through emulsification in a controlled manner. The viruses form fibrous nanostructures of several micrometers length, which are much longer than the original virus. Subsequently, the fibers self-assemble into well-packed ordered microstructures. Furthermore, the resultant hierarchically assembled structures showed long-term stability and potential applicability through the desired functionalization.

Angiogenesis in the Septum and Inner Membrane of Refractory Chronic Subdural Hematomas: Consideration of Findings after Middle Meningeal Artery Embolization with Low-concentration n-butyl-2-cyanoacrylate.

The middle meningeal artery (MMA) is suggested to play an important role in the recurrence of chronic subdural hematomas (CSDHs). However, the exact mechanisms involved in the recurrence of CSDHs still remain unknown. For recurring CSDHs, MMA embolization is performed using low-concentration n-butyl-2-cyanoacrylate (NBCA) at our hospital. We report new findings and a discussion related to the mechanism of CSDH recurrence based on the imaging findings after MMA embolization, and cases that required craniotomy due to recurrence. The study included eight patients with recurrent CSDH, defined as ipsilateral hematoma re-enlargement within 3 months, and treated with MMA embolization. MMA embolization was performed successfully in all eight patients with no complications. Of the eight patients treated, one patient required craniotomy for the evacuation of CSDHs due to hematoma re-enlargement. NBCA casts were observed in the inner membrane of CSDHs in five of the eight patients by postoperative computed tomography scans. In the case that required craniotomy, the formation of neovasculatures was observed in the inner membrane of the CSDH. Our results suggested that angiogenesis also occurs in the septum and inner membrane through the MMA and the outer membrane of the CSDH. Additionally, these neovascular vessels may be involved in the recurrence of CSDH after MMA embolization. In a future larger study, it is necessary to elucidate in detail the vascular architecture of the CSDH membrane associated with the hematoma re-enlargement, and the effectiveness of MMA embolization that embolized to these peripheral neovascular vessels.

Embryological Consideration of Dural AVFs in Relation to the Neural Crest and the Mesoderm.

Intracranial and spinal dural arteriovenous fistulas (DAVFs) are vascular pathologies of the dural membrane with arteriovenous shunts. They are abnormal communications between arteries and veins or dural venous sinuses that sit between the two sheets of the dura mater. The dura propria faces the surface of brain, and the osteal dura faces the bone. The location of the shunt points is not distributed homogeneously on the surface of the dural membrane, but there are certain areas susceptible to DAVFs. The dura mater of the olfactory groove, falx cerebri, inferior sagittal sinus, tentorium cerebelli, and falx cerebelli, and the dura mater at the level of the spinal cord are composed only of dura propria, and these areas are derived from neural crest cells. The dura mater of the cavernous sinus, transverse sinus, sigmoid sinus, and anterior condylar confluence surrounding the hypoglossal canal are composed of both dura propria and osteal dura; this group is derived from mesoderm. Although the cause of this heterogeneity has not yet been determined, there are some specific characteristics and tendencies in terms of the embryological features. The possible reasons for the segmental susceptibility to DAVFs are summarized based on the embryology of the dura mater.