Transplantation of pancreatic beta-cell spheroids in mice via non-swellable hydrogel microwells composed of poly(HEMA-co-GelMA).

Pancreatic islet transplantation is an effective treatment for type I diabetes mellitus. However, many problems associated with pancreatic islet engraftment remain unresolved. In this study, we developed a hydrogel microwell device for islet implantation, fabricated by crosslinking gelatin-methacryloyl (GelMA) and 2-hydroxyethyl methacrylate (HEMA) in appropriate proportions. The fabricated hydrogel microwell device could be freeze-dried and restored by immersion in the culture medium at any time, allowing long-term storage and transport of the device for ready-to-use applications. In addition, due to its non-swelling properties, the shape of the wells of the device was maintained. Thus, the device allowed pancreatic ß cell lines to form spheroids and increase insulin secretion. Intraperitoneal implantation of the ß cell line-seeded GelMA/HEMA hydrogel microwell device reduced blood glucose levels in diabetic mice. In addition, they were easy to handle during transplantation and were removed from the transplant site without peritoneal adhesions or infiltration by inflammatory cells. These results suggest that the GelMA/HEMA hydrogel microwell device can go from spheroid and/or organoid fabrication to transplantation in a single step.

A Case of Microguidewire and Neuroform Atlas Stent Entanglement Resulting in Extraction Difficulty.

Objective: The trans-cell technique in stent-assisted coil embolization is a common treatment method for intracranial aneurysm. However, despite the frequency of its use, reports discussing its complications and their management are few. We describe a case of stent and microguidewire entanglement, which could not be removed, during treatment using the trans-cell technique. We discuss the mechanism of the entanglement and its management. Case Presentation: A woman in her 40s was found to have an unruptured cerebral aneurysm with a maximum diameter of 5.9 mm located in the paraclinodal anterior process of the left internal carotid artery during a close examination of a headache. The aneurysm had an irregular shape and wide neck. Stent-assisted coil embolization was planned. Initially, the coil was embolized using a jailing technique, but the microcatheter was pushed out of the aneurysm during embolization. Thus, we attempted to switch to a trans-cell technique. However, during the process, the stent and microguidewire became entangled and could not be removed. Finally, when the stent slipped off, the entanglement was resolved and the microguidewire was retrieved. Fortunately, the patient was discharged home without postoperative complications. Conclusion: Once a stent and a microguidewire become entangled, safely releasing them is difficult. Thus, it is important to avoid this scenario from occurring.

Facet joint thickness and lumbar instability documented on myelo-computed tomography studies in patients with lumbar degenerative disease.

Background: Various indicators of vertebral instability in patients with lumbar degenerative disease can be identified in myelo-computed tomography (CT) studies. Methods: Of 120 patients, 45 with lumbar degenerative spondylolisthesis (LDS; 53 lumbar lesions) and 75 with lumbar spinal stenosis alone (LSS; 105 lesions) (2015-2019) myelo-CT studies and surgery confirmed the presence of lumbar instability. Myelo-CT findings indicative of instability included facet joint thickness (FJT), fluid in the facet joint, facet tropism, and air in the facet and/or disc. Results: For the 120 study patients, FJT was significantly elevated in both the LDS and LSS groups. Conclusion: FJT on myelo-CT is more specific for lumbar instability than other imaging parameters when evaluating LDS. An increase in FJT suggests vertebral instability likely warranting fusion.

Multiple large vessel occlusions resulting in vessel perforation in single pass of mechanical thrombectomy with stent retriever.

Mechanical thrombectomy (MT) is a highly effective treatment for acute ischemic stroke, and hemorrhagic complications caused by vessel injury are rare. However, there is no evidence regarding the efficacy of MT for multiple large vessel occlusion or its procedural strategy. Herein, we report a case of MT with a stent retriever for multiple large vessel occlusion in the internal carotid artery and middle cerebral artery M1 distal, which resulted in vessel perforation in a single pass. A 79-year-old woman underwent MT for internal carotid artery occlusion, and multiple large vessel occlusion was observed on digital subtraction angiography. A longer and larger stent retriever was selected for thrombus retrieval in a single pass. Immediately after retrieval, digital subtraction angiography revealed internal carotid artery recanalization. Then, extravasation was observed from the M1 distal occlusion. Treatment was interrupted after hemostasis was confirmed. Nevertheless, rebleeding occurred after 4 hours. Emergency trapping was performed, and vessel perforation of >1 mm was observed. When retrieving a thrombus in a single pass with a stent retriever for multiple large vessel occlusion, vessel perforation may occur if the device is selected according to the diameter of the proximal occluded vessel. Based on the type of device, even a single pass may result in vessel perforation. Although aggressive MT intervention should be performed for multiple large vessel occlusion, a device that is appropriate for the pathological condition must be selected.

A case of infectious intracranial aneurysm that formed and ruptured within a few days after occlusion of the proximal middle cerebral artery by infective endocarditis.

Background: Embolic cerebral infarction and infectious intracranial aneurysms (IIAs) are well-known central nervous system complications of infective endocarditis (IE). In this report, we describe a rare case of cerebral infarction caused by the occlusion of the M2 inferior trunk due to IE, followed by the rapid formation and rupture of IIA. Case Description: A 66-year-old woman was admitted to the hospital with a diagnosis of IE and embolic cerebral infarction after being brought to the emergency department with a 2-day history of fever and difficulty walking. After admission, she was immediately started on antibiotic therapy. Three days later, the patient suddenly became unconscious, and a head computed tomography (CT) scan showed massive cerebral hemorrhage and subarachnoid hemorrhage. Contrast-enhanced CT showed a 13-mm large aneurysm in the left middle cerebral artery (MCA) bifurcation. An emergency craniotomy was performed, and intraoperative findings revealed a pseudoaneurysm at the origin of the M2 superior trunk. Clipping was considered difficult, so trapping and internal decompression were performed. The patient died on the 11th day after surgery due to the worsening of her general condition. The pathology of the excised aneurysm was consistent with a pseudoaneurysm. Conclusion: IE may cause occlusion of the proximal MCA and rapid formation and rupture of IIA. It should be noted that the location of IIA may be a short distance away from the occlusion site.

Case of effective suction to secure the true lumen for acute occlusion after carotid endarterectomy.

During or following carotid endarterectomy, dissection and occlusion of the internal carotid artery can occur. In cases of stenosis or almost complete occlusion, recanalization is relatively easy; however, in cases of complete occlusion, advancing a guidewire into the true lumen may be challenging. Few reports on how to address this problem have been published. Here, we report a case of suction-enabled advancement of the wire into the true lumen during endovascular treatment of an acute occlusion of the internal carotid artery after carotid endarterectomy. An 80-year-old man underwent carotid endarterectomy; the next morning, he exhibited aphasia and right-sided paralysis, and magnetic resonance images showed left cerebral infarction and left internal carotid artery occlusion. The patient was transferred to our hospital for recanalization. Imaging with contrast material showed that the left internal carotid artery was completely occluded. During recanalization, futile attempts were made to advance the wire into the true lumen. The occlusion was aspirated, and angiography then showed an inflow of contrast material into the vessel, which indicated slight distal widening; this widening allowed the wire to move into the true lumen. The occlusion extended distally, and 2 stents were placed over the entire lesion. Good recanalization was eventually achieved.

Demonstration of an intense lithium beam for forward-directed pulsed neutron generation.

As an alternative to research nuclear reactors, a compact accelerator-driven neutron generator that uses a lithium beam driver could be a promising candidate since it produces almost no undesired radiation. However, providing an intense lithium-ion beam has been difficult, and it has been thought that the practical application of such a device would be impossible. The most critical problem of insufficient ion fluxes has been solved by applying a direct plasma injection scheme. In this scheme, a pulsed high-density plasma from a metallic lithium foil generated by laser ablation is efficiently injected and accelerated by a radio-frequency quadrupole linear accelerator (RFQ linac). We have obtained a peak beam current of 35 mA accelerated to 1.43 MeV, which is two orders of magnitude higher than a conventional injector and accelerator system can deliver.

Clinical and Morphological Characteristics of Ruptured Small (<5 mm) Posterior Communicating Artery Aneurysms.

CONTEXT: Small intracranial aneurysms (IAs) are considered to have a low risk of rupture; however, in clinical practice, we often encounter patients with subarachnoid hemorrhage (SAH) due to rupture of small IAs. AIMS: This study aims to clarify the clinical and morphological characteristics of ruptured small IA, focusing on posterior communicating artery (PCoA) aneurysms as a prone site. SETTINGS AND DESIGN: We retrospectively reviewed 102 consecutive patients with SAH due to ruptured PCoA aneurysm who underwent microsurgical or endovascular aneurysm repair between April 2013 and March 2018. SUBJECTS AND METHODS: All PCoA aneurysms were diagnosed using three-dimensional rotation angiography or three-dimensional computed tomography angiography. Information regarding the following clinical characteristics was collected: age, sex, past medical history, current smoking, antithrombotic therapy, multiplicity, hydrocephalus, intracerebral hemorrhage, intraventricular hemorrhage, and World Federation of Neurosurgical Societies (WFNS) Grade on admission. STATISTICAL ANALYSIS USED: We analyzed factors of ruptured small IA, focusing on PCoA aneurysms using univariate and multivariate regression analyses. RESULTS: Univariate and multivariate analyses revealed that low aspect ratio (AR) (odds ratio [OR] = 0.33, P = 0.01) and nonfetal type of PCoA (OR = 0.31, P = 0.02) might be independent characteristics of ruptured small PCoA aneurysms. However, age, sex, past medical history, WFNS grade, and treatment outcome were not different between the small and nonsmall PCoA aneurysms. The aneurysm size was not associated to the selection of treatment, proportion of complications, and treatment outcome. CONCLUSIONS: In cases of ruptured PCoA aneurysms, low AR and nonfetal type of PCoA might be associated with rupture of small aneurysms.

Plasma instability inside solenoid with laser ion source.

Using a solenoid with a laser ion source can suppress divergence of the expanding plasma; however, it has been found that the plasma becomes unstable in a certain magnetic field region. In the previous research, instability of the plasma after the solenoid was found. In this study, we investigated how the plasma instability changes inside the solenoid. A Faraday cup was placed in the solenoid, and the unstable magnetic field range was investigated. This experiment was conducted while changing the Faraday cup position from the inlet to the outlet of the solenoid. By increasing the magnetic field strength, the Faraday cup position indicating a condition triggering instability moved toward upstream in the solenoid. In addition, the instability is gradually mitigated by transporting the laser ablation plasma through the rest of the solenoid. The detailed good working range of the solenoid for the Au1+ beam was also shown.

A case report of microvascular decompression for cervical myelopathy and radiculopathy caused by tortuous and abnormal bilateral vertebral artery.

BACKGROUND: Tortuous/abnormal vertebral arteries (VAs) sometimes cause neurovascular compression syndromes (NVCs), such as trigeminal neuralgia, hemifacial spasm, and, rarely, myelopathy/radiculopathy. Abnormalities/tortuosity of the VA at the level of the atlas and axis are of particular note; these may be characterized by a persistent first intersegmental artery (PFIA) and C2 segmental type of VA. Herein, we report a 72-year-old male who presented with cervical myelopathy/radiculopathy due to bilateral tortuosity of the PFIA resulting in spinal cord compression at the craniocervical junction. CASE DESCRIPTION: A 72-year-old male presented with cervical pain when turning his neck and progressive gait disturbance. The neurological examination demonstrated a moderate myeloradicular syndrome (Nurick Grade III). The magnetic resonance revealed compression of the medulla and spinal cord due to tortuosity of both dorsal VA at the C1 vertebral level. The three-dimensional computed tomography angiogram confirmed bilateral PFIA running medially. In addition, the left side of VA forms fenestration. Surgery through a C1 laminectomy and midline small suboccipital craniectomy, both VAs were transposed and tethered to the ipsilateral dura utilizing Aron Alpha and vinyl prostheses. In addition, a large vinyl prosthesis was inserted between both VAs to protect them from contacting the spinal cord. Following this decompressive procedure, the patient's symptoms fully resolved, and he remains asymptomatic 10 years later exhibiting no recurrent vascular pathology. CONCLUSION: Microvascular decompression of anomalous VAs contributing to cord compression at the C1 level was safe and effective in a 72-year-old male.

Neutron generator based on intense lithium beam driver.

We are proposing a compact neutron generator based on a Li beam driver. The proposed neutron generator comprises a laser ion source, a radio-frequency quadrupole linear accelerator (RFQ linac), a drift tube linac, and a target containing protons. In the generator, the lithium ion is used as a projectile instead of protons to utilize the kinematic focusing technique. The technique enables us to enhance the neutron flux without increasing the beam energy, which is important to develop a clean compact neutron generator. Moreover, the combination of a laser ion source and a RFQ linac with the direct plasma injection scheme will provide several tens of mA of a fully ionized lithium beam, which is much higher than that of conventional heavy ion sources comparable with proton drivers. Neutrons are generated by the nuclear reaction of the lithium ions and protons in the beam target. In this paper, we reported the current status of the development. For RFQ, we designed the RFQ rods to accelerate 40 mA of 7Li3+. We fabricated and installed the rods into a cavity, and, as a first test, accelerated 10 mA of C6+ successfully.

Evaluation of magnetic field error in ExtendedEBIS.

The upgrade of the EBIS, called ExtendedEBIS, is now in progress in Brookhaven National Laboratory. Two 5T-superconducting solenoids have been placed in series with 200 mm distance from each other for higher trap capacity and production of polarized 3He ions. Since the two superconducting solenoids are used, the field error is expected to be larger. In this research, the field error is estimated based on simulation. It was found that the magnetic field line can be 17 mm off from the center axis at the entrance of the collector, and this offset can be adjusted by three types of correction coils. Additionally, mismatch of the spin direction of polarized 3He due to the misalignment was estimated to be small.

Laser power density dependence on charge state distribution of Ta ion laser plasma.

Laser power density per pulse, which is commonly expressed with the unit of "W/cm2," is an important parameter to characterize ablation plasma. To match a design charge state of heavy ion beam induced by a laser ion source, a laser power density must be carefully chosen. Above around 108 W/cm2 of laser power density, laser ablation plasma is emitted from the surface of solid material. Then, up to 109 W/cm2, the most abundant charge state is 1+. Because the ionization energy increases with higher charge states, increasing the laser intensity leads to the charge state distribution shifting higher. Increasing the density to increase charge states also results in lower time of flight due to higher velocities. The maximum laser power density is obtained by the smallest available laser spot size on the target material which is determined by the quality of the laser beam. For many accelerator applications, higher charge state beams are preferred. In particular cases, singly charge ion beams are demanded. Therefore, production of intermediate charge state beams has not been investigated well. In this study, we selected Ta4+ as an example demanded beam and tried to clarify how the transition of charge state distribution depends on laser power density. Conclusively, the possible specification of a laser ion source for Ta4+ delivery was elucidated.

Low charge state lithium beam production from chemical compounds with laser ion source.

In recent years, the primary ion source for the Brookhaven National Laboratory has been the laser ion source, which provides many types of ions within a short switching time of several seconds. The task is difficult for other ion sources. In the previous work, we tested metallic lithium as a target material of the laser irradiation. Although an intense lithium beam was demonstrated, some operational difficulties were observed due to its reactiveness to oxygen. For accelerator applications, a more robust and reliable target material has been demanded. For this purpose, we tested lithium niobate, LiNbO3. Our study investigated the optimization of power density to produce low charge state lithium ions. We struck LiNbO3 with the laser and found lithium ion quantities for five different power densities. Based on the data obtained, we can conclude that the most efficient production of Li1+ occurs when the laser power density is 5 × 108 W/cm2.

Predictors of subacute hematoma expansion requiring surgical evacuation after initial conservative treatment in patients with acute subdural hematoma.

BACKGROUND: The aim of this study was to clarify the factors associated with requiring subacute surgery in patients with acute subdural hematoma (ASDH) treated conservatively at admission. METHODS: Among the patients with ASDH admitted to our hospital from 2007 to 2018, we retrospectively reviewed data for 200 patients initially treated conservatively. We compared patients' characteristics, medical history, radiological findings, and clinical outcomes and differences between patients undergoing subacute surgery or no surgery. RESULTS: Of the 200 patients treated conservatively, 17 (8.5%) patients underwent subacute surgery due to deterioration of their clinical and/or computed tomography (CT) findings, while 183 (91.5%) patients did not undergo subacute surgery. There were significant differences in the presence of focal neurological deficits, modified Rankin Scale scores, degree of midline shift, hematoma thickness, hematoma volume, cella media index, Sylvian fissure ratio, and hematoma density between the two groups. CONCLUSIONS: Large hematoma, brain atrophy, and hematoma density may be useful predictors for the need for subacute surgery in patients with ASDH treated conservatively at admission. Intensive investigation of clinical findings or CT images is warranted in patients with adverse prognostic factors, even if their initial symptoms are mild.

A rare case of diploic venous anomaly: asymptomatic venous sac expanding in the diploe.

BACKGROUND: Vascular anomalies accompanied with the diploic veins are rare. Among them, sinus pericranii, which is characterized by abnormal connections between intra- and extracranial venous systems, is relatively common. Besides sinus pericranii, a few cases of subepicranial varix with connections to diploic veins have been reported, but these varices had no connections to intracranial venous sinuses. Herein, we present a rare case of an expanding venous sac in the diploe which communicated with the intracranial sinus but not with the extracranial venous systems. CASE PRESENTATION: An adult woman presented to us with a minor transient headache. Although no abnormal appearances were found on her scalp, imaging studies showed a club-shaped venous sac in the left parietal diploe that communicated with the superior sagittal sinus and diploic veins on the medial and lateral sides, respectively. It was revealed that the lesion had expanded as compared with a previous computed tomography image. Surgery was performed to intercept venous supply from the diploic veins, and the lesion was filled with thrombi. In a follow-up of 15 months, there was no recurrence of abnormal venous flow. Histological examination showed the endothelial lining in the membranous wall of the sac, which is typically observed in sinus pericranii. However, no communication with the pericranial veins of the scalp was identified on the imaging studies and intraoperative observation. Accordingly, it was diagnosed as another entity "intradiploic varix". CONCLUSIONS: The abnormal connection between the intracranial and the diploic venous systems via the large venous sac was surgically treated. It was pathologically similar to sinus pericranii, but anatomically considered to be another form of venous anomaly. In cases of expanding lesions, surgical treatment is recommended.

Contribution of material's surface layer on charge state distribution in laser ablation plasma.

To generate laser ablation plasma, a pulse laser is focused onto a solid target making a crater on the surface. However, not all the evaporated material is efficiently converted to hot plasma. Some portion of the evaporated material could be turned to low temperature plasma or just vapor. To investigate the mechanism, we prepared an aluminum target coated by thin carbon layers. Then, we measured the ablation plasma properties with different carbon thicknesses on the aluminum plate. The results showed that C(6+) ions were generated only from the surface layer. The deep layers (over 250 nm from the surface) did not provide high charge state ions. On the other hand, low charge state ions were mainly produced by the deeper layers of the target. Atoms deeper than 1000 nm did not contribute to the ablation plasma formation.

'Papillary' solitary fibrous tumor/hemangiopericytoma with nuclear STAT6 expression and NAB2-STAT6 fusion.

This report describes clinicopathological findings, including genetic data of STAT6, in a solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) of the central nervous system in an 83-year-old woman with a bulge in the left forehead. She noticed it about 5 months before, and it had grown rapidly for the past 1 month. Neuroradiological studies disclosed a well-demarcated tumor that accompanied the destruction of the skull. The excised tumor showed a prominent papillary structure, where atypical cells were compactly arranged along the fibrovascular core ('pseudopapillary'). There was rich vasculature, some of which resembled 'staghorn' vessels. Mitotic figures were occasionally found. Whorls, psammoma bodies, or intra-nuclear pseudoinclusions were not identified. By immunohistochemistry, CD34 was strongly positive in the tumor cells, and STAT6 was localized in their nuclei. By reverse transcription-polymerase chain reaction (RT-PCR), an NAB2-STAT6 fusion gene, NAB2 exon6-STAT6 exon17, was detected, establishing a definite diagnosis of SFT/HPC. 'Papillary' SFT/HPC needs to be recognized as a possible morphological variant of SFT/HPC, and should be borne in mind in its diagnostic practice.

Ruptured posterior spinal artery aneurysm: intraoperative and histologic findings with appreciable thrombosis.

BACKGROUND CONTEXT: Little is known on the natural course of ruptured spinal artery aneurysm, and a treatment strategy remains to be elucidated. PURPOSE: This case report aims to describe a rare case of a posterior spinal artery aneurysm that showed progressive thrombosis following subarachnoid hemorrhage. STUDY DESIGN: This is a case report and literature review. METHODS: A 54-year-old man presented with subarachnoid hemorrhage due to posterior spinal artery aneurysm at the T10 level. The patient underwent surgery 19 days after onset. RESULTS: Most of the aneurysm appeared unenhanced on intraoperative indocyanine green video angiography, and total resection was performed. Histologic examination confirmed spontaneous thrombosis of the lesion. A review of the literature identified 19 cases of ruptured posterior spinal artery aneurysm. Thrombosed aneurysm and thrombosed parent artery were observed in 7 (44%) of the 16 cases treated with surgical or endovascular interventions. In the three cases treated conservatively, fatal rebleeding in the acute stage was noted in one case, whereas the lesion disappeared spontaneously in the chronic stage without rebleeding in two cases. CONCLUSIONS: Ruptured spinal artery aneurysms are prone to spontaneous thrombosis. The healing process of the lesion was well documented in the present case. Repeated angiographic follow-up offers a feasible alternative in the management of this fairly rare aneurysm.

Factor B Is the Second Lipopolysaccharide-binding Protease Zymogen in the Horseshoe Crab Coagulation Cascade.

Factor B is a serine-protease zymogen in the horseshoe crab coagulation cascade, and it is the primary substrate for activated factor C, the LPS-responsive initiator of the cascade. Factor C is autocatalytically activated to α-factor C on LPS and is artificially converted to ß-factor C, another activated form, by chymotrypsin. It is not known, however, whether LPS is required for the activation of factor B. Here we found that wild-type factor B expressed in HEK293S cells is activated by α-factor C, but not by ß-factor C, in an LPS-dependent manner and that ß-factor C loses the LPS binding activity of factor C through additional cleavage by chymotrypsin within the N-terminal LPS-binding region. Surface plasmon resonance and quartz crystal microbalance analyses revealed that wild-type factor B binds to LPS with high affinity comparable with that of factor C, demonstrating that factor B is the second LPS-binding zymogen in the cascade. An LPS-binding site of wild-type factor B was found in the N-terminal clip domain, and the activation rate of a clip domain deletion mutant was considerably slower than that of wild-type factor B. Moreover, in the presence of LPS, Triton X-100 inhibited the activation of wild-type factor B by α-factor C. We conclude that the clip domain of factor B has an important role in localizing factor B to the surface of Gram-negative bacteria or LPS released from bacteria to initiate effective proteolytic activation by α-factor C.