Virtual Reality Self Co-Embodiment: An Alternative to Mirror Therapy for Post-Stroke Upper Limb Rehabilitation.

We present Virtual Reality Self Co-embodiment, a new method for post-stroke upper limb rehabilitation. It is inspired by mirror therapy, where the patient's healthy arm is involved in recovering the affected arm's motion. By tracking the user's head, wrists, and fingers' positions, our new approach allows the handicapped arm to control a digital avatar in order to pursue a reaching task. We apply the concept of virtual co-embodiment to use the information from the unaffected arm and complete the affected limb's impaired motion, which is our added unique feature. This requires users to mechanically involve the incapacitated area as much as possible, prioritizing actual movement rather than the sole imagination of it. As a result, subjects will see a seemingly normally functional virtual arm primarily controlled by their handicapped extremity, but with the constant support of their healthy limb's motion. Our experiment compares the task execution performance and embodiment perceived when interacting with both mirror therapy and our proposed technique. We found that our approach's provided sense of ownership is mildly impacted by users' motion planning response times, which mirror therapy does not exhibit. We also observed that mirror therapy's sense of ownership is moderately affected by the subject's proficiency while executing the assigned task, which our new method did not display. The results indicate that our proposed method provides similar embodiment and rehabilitation capabilities to those perceived from existing mirror therapy. This experiment was performed in healthy individuals to have an unbiased comparison of how mirror therapy's and VRSelfCo's task performance and degree of virtual embodiment compare, but future work explores the possibility of applying this new approach to actual post-stroke patients.

Gallbladder perforation following peroral cholangioscopy-guided lithotripsy: A case report.

Peroral cholangioscopy-guided lithotripsy is highly effective in clearing difficult bile duct stones. It can cause adverse events, such as cholangitis and pancreatitis; however, gallbladder perforation is extremely rare. Herein, we describe the case of a 77-year-old woman who developed gallbladder perforation following peroral cholangioscopy -guided lithotripsy. She was referred to our hospital to treat multiple large bile duct stones. She underwent peroral cholangioscopy-guided lithotripsy because of conventional lithotripsy failure. After a cholangioscope was advanced into the bile duct, saline irrigation was used for visualization. Electronic hydraulic lithotripsy was performed, but it took time for fragmentation because the calculus was hard. The 2-h endoscopic procedure did not completely remove the stone, and treatment was discontinued after placing a biliary plastic stent and nasobiliary tube. After the endoscopic procedure, she started experiencing right hypochondrial pain, which worsened the next day. Computed tomography showed a gallbladder wall defect in the gallbladder fundus with pericholecystic fluid. She was diagnosed with gallbladder perforation and underwent emergency surgery. A perforation site was found at the gallbladder fundus. Open cholecystectomy, choledochotomy, and extraction of residual bile duct stones were performed. The patient was discharged 9 days post-surgery without any complications. The saline irrigation used for visualization may have caused a surge in intra-gallbladder pressure, resulting in gallbladder perforation. Therefore, endoscopists may need to conserve irrigation water during peroral cholangioscopy-guided lithotripsy.

Comprehensive evaluation of three-dimensional anatomy of perigastric vessels using enhanced multidetector-row computed tomography.

BACKGROUND: To perform laparoscopic gastrectomy safely, we aimed to comprehensively re-evaluate perigastric vessel anatomies using a three-dimensional angiography reconstructed from enhanced multidetector-row computed tomography data. METHODS: Perigastric vessel anatomy was preoperatively analyzed using a multidetector-row computed tomography-based three-dimensional angiography reconstructed in 127 patients undergoing gastric surgery. RESULTS: Of the 67 left gastric veins that ran along the dorsal side of the arteries, 59 (88.1%) ran along the dorsal side of the common hepatic artery and flowed into the portal vein. In 18 cases, a common trunk of one to three left gastric arteries and the replaced left hepatic artery was observed. The left inferior phrenic artery ramified from the left gastric artery in 5.5% of the cases. The right gastric artery was classified into distal (73.2%), caudal (18.1%), and proximal (8.7%) types. The infra-pyloric artery was also classified into distal (64.6%), caudal (26.0%), and proximal (9.4%) types. The posterior gastric artery branched as a common trunk with the superior polar artery in the proximal (37.9%) and distal (18.4%) regions of the splenic artery. The left gastroepiploic artery ramified from the splenic (18.1%) and inferior terminal arteries (81.9%). No, one, and two gastric branches of the left gastroepiploic artery, which ramified between the roots of the left gastroepiploic artery and its omental branch, were found in 36.5%, 49.2%, and 14.3% of the cases, respectively. CONCLUSIONS: Preoperative 3D angiography is useful for the precise evaluation of perigastric vessel anatomies, and may help us to perform laparoscopic gastrectomy and robotic surgery safely.

Radiological and clinical features of twig-like middle cerebral artery in comparison with moyamoya angiopathy: a multicenter retrospective study.

OBJECTIVE: Twig-like middle cerebral artery (T-MCA) is a rare congenital anomaly that is difficult to distinguish from moyamoya angiopathy (MMA), given the similarity of the angioarchitectures. The aim of this study was to gain insights into the radiological and clinical features of T-MCA and to distinguish this condition from MMA. METHODS: A multicenter retrospective study was conducted in 29 patients with T-MCA and 57 patients with MMA. Demographic, radiological, and clinical data were compared between the patients with T-MCA and those with MMA. RESULTS: The T-MCA group tended to be older than the MMA group (mean age 47 ± 18 vs 39 ± 22 years). Twenty patients with T-MCA (69%) were initially diagnosed with MMA. All T-MCA cases had twig-like networks and steno-occlusive changes involving the MCA. The T-MCA group had a higher incidence of intracranial aneurysms (35% vs 11%) and coexisting arterial anomalies (48% vs 12%). T-MCA and MMA cases had significant differences in involvement of the internal carotid artery terminus (0% vs 100%) and posterior cerebral artery (0% vs 23%), and in transdural anastomosis (0% vs 51%). T-MCA cases were less likely to present with stroke (59% vs 86%) and more likely to be asymptomatic (28% vs 12%). Of the patients with stroke, those with T-MCA had more hemorrhagic strokes (41% vs 29%) and fewer ischemic strokes (59% vs 71%) compared to those with MMA. CONCLUSIONS: This study suggests that T-MCA is a different disease entity from MMA based on significant differences in the radiological and clinical features. Neurosurgeons should recognize this anomaly and understand the key features that differentiate T-MCA from MMA.

Geospatial Assessments of DNA Adducts in the Human Stomach: A Model of Field Cancerization.

BACKGROUND: Field cancerization is a popular concept regarding where cancer cells arise in a plane, such as the opened-up gastrointestinal mucosa. The geospatial distribution of DNA adducts, some of which are believed to initiate mutation, may be a clue to understanding the landscape of the preferred occurrence of gastric cancer in the human stomach, such that the occurrence is much more frequent in the lesser curvature than in the greater curvature. METHODS: Seven DNA adducts, C5-methyl-2'-deoxycytidine, 2'-deoxyinosine, C5-hydroxymethyl-2'-deoxycytidine, N6-methyl-2'-deoxyadenosine, 1,N6-etheno-2'-deoxyadenosine, N6-hydroxymethyl-2'-deoxyadenosine, and C8-oxo-2'-deoxyguanosine, from different points and zones of the human stomach were semi quantitatively measured by liquid chromatography/tandem mass spectrometry. The differences in the quantity of these DNA adducts from the lesser and greater curvature, the upper, middle and lower third zones, the anterior and posterior wall of the stomach, and the mucosae distant from and near the tumor were compared to determine whether the location preference of cancer in the stomach could be explained by the distribution of these DNA adducts. Comparisons were conducted considering the tumor locations and operation methods. CONCLUSIONS: Regarding the DNA adducts investigated, significant differences in quantities and locations in the whole stomach were not noted; thus, these DNA adducts do not explain the preferential occurrence of cancer in particular locations of the human stomach.

Redirected Walking using Continuous Curvature Manipulation.

In this paper, we propose a novel redirected walking (RDW) technique that applies dynamic bending and curvature gains so that users perceive less discomfort than existing techniques that apply constant gains. Humans are less likely to notice continuous changes than those that are sudden. Therefore, instead of applying constant bending or curvature gains to users, we propose a dynamic method that continuously changes the gains. We conduct experiments to investigate the effect of dynamic gains in bending and curvature manipulation with regards to discomfort. The experimental results show that the proposed method significantly suppresses discomfort by up to 16 and 9% for bending and curvature manipulations, respectively.

Mass spectrometric profiling of DNA adducts in the human stomach associated with damage from environmental factors.

BACKGROUND: A comprehensive understanding of DNA adducts, one of the most plausible origins of cancer mutations, is still elusive, especially in human tissues in clinical settings. Recent technological developments have facilitated the identification of multiple DNA adducts in a single experiment. Only a few attempts toward this "DNA adductome approach" in human tissues have been reported. Geospatial information on DNA adducts in human organs has been scarce. AIM: Mass spectrometry of human gastric mucosal DNA was performed to identify DNA adducts associated with environmental factors. MATERIALS AND METHODS: From 59 subjects who had received gastrectomy for gastric cancer, 306 samples of nontumor tissues and 15 samples of tumors (14 cases) were taken for DNA adductome analysis. Gastric nontumor tissue from autopsies of 7 subjects without gastric cancer (urothelial cancer, hepatocellular carcinoma, lung cancer each; the other four cases were without any cancers) was also investigated. Briefly, DNA was extracted from each sample with antioxidants, digested into nucleosides, separated by liquid chromatography, and then electrospray-ionized. Specific DNA adducts were identified by mass/charge number and column retention time compared to standards. Information on lifestyle factors such as tobacco smoking and alcohol drinking was taken from the clinical records of each subject. RESULTS: Seven DNA adducts, including modified bases, C5-methyl-2'-deoxycytidine, 2'-deoxyinosine, C5-hydroxymethyl-2'-deoxycytidine, N6-methyl-2'-deoxyadenosine, 1,N6-etheno-2'-deoxyadenosine, N6-hydroxymethyl-2'-deoxyadenosine, and C8-oxo-2'-deoxyguanosine, were identified in the human stomach and characterized. Intraindividual differences according to the multiple sites of these adducts were noted but were less substantial than interindividual differences. N6-hydroxymethyl-2'-deoxyadenosine was identified in the human stomach for the first time. The amount of C5-hydroxymethyl-2'-deoxycytidine was higher in the stomachs of subjects without gastric cancer than in the nontumor and tumor portions of the stomach in gastric cancer patients. Higher levels of 1,N6-etheno-2'-deoxyadenosine were detected in the subjects who reported both smoking and drinking than in those without these habits. These DNA adducts showed considerable correlations with each other. CONCLUSIONS: We characterized 7 DNA adducts in the nontumor portion of the human stomach in both gastric cancer subjects and nongastric cancer subjects. A reduction in C5-hydroxymethyl-dC even in the nontumor mucosa of patients with gastric cancer was observed. Smoking and drinking habits significantly influenced the quantity of one of the lipid peroxidation-derived adducts, etheno-dA. A more expansive DNA adductome profile would provide a comprehensive understanding of the origin of human cancer in the future.

Endovascular Mechanical Thrombectomy for Basilar Artery Occlusion Caused by Thrombosis as an Initial Manifestation of Acute Myelogenous Leukemia: A Case Report.

We report a rare case of a basilar artery occlusion (BAO) caused by thrombosis as an initial magnification of acute myelogenous leukemia (AML) and performed mechanical thrombectomy (MT) to treat it. A 67-year-old female presented left hemiparalysis of her arm and right-sided blindness. Magnetic resonance imaging (MRI) and magnetic resonance angiography revealed acute infarction in the left occipital and anterior lobes of the cerebellum and incomplete BAO. Her blood test showed hyperleukocytosis with precursor cells and high levels of C-reactive protein, and we diagnosed AML and disseminated intravascular coagulation (DIC). We decided to treat conservatively with rapid rehydration and heparin, but three hours after admission, she suddenly lost consciousness. We performed acute MT with a direct aspiration first-pass technique (ADAPT). A white elastic embolus was aspirated, and DSA showed successful recanalization of the basilar artery. The next day, MRI revealed acute infarction in the midbrain and bilateral thalamus. The patient remained unconscious after MT and so chemotherapy to treat the acute leukemia could not be performed. The patient died of the primary disease 14 days after BAO. Thrombosis in association with AML is very rare disease and could occur in arterial vessels because of hypercoagulation, and this tendency may not respond to anticoagulation therapy. Although ADAPT might be performed safety without complications even in cases of DIC, indications for treatment with MT should be carefully considered in patients in whom hemorrhage is a possibility.

Double LVIS Jr. Stenting of a Ruptured Proximal Anterior Inferior Cerebellar Artery Aneurysm: A Case Report.

Objective: We report a case of ruptured aneurysm at the anterior pontine segment of the anterior inferior cerebellar artery (AICA) which re-ruptured after stent placement and was treated by overlapping stenting. Case Presentation: A 53-year-old woman presented with headache. CT demonstrated subarachnoid hemorrhage. DSA revealed no evident source of bleeding. On day 10, she complained of sudden headache and CT demonstrated re-bleeding. On repeated DSA, an aneurysm at the anterior pontine segment of the right AICA was found. An LVIS Jr. stent was deployed at the right AICA including the aneurysm. On postoperative day 23, the aneurysm ruptured again. Another LVIS Jr. stent was deployed at the same area. On day 56, she was discharged home without neurological deficit. Conclusion: Intracranial aneurysms not indicated for coil embolization or parent artery occlusion are difficult to treat. Overlapping stenting may be a treatment option for such aneurysms.

Ascending and Descending in Virtual Reality: Simple and Safe System Using Passive Haptics.

This paper presents a novel interactive system that provides users with virtual reality (VR) experiences, wherein users feel as if they are ascending/descending stairs through passive haptic feedback. The passive haptic stimuli are provided by small bumps under the feet of users; these stimuli are provided to represent the edges of the stairs in the virtual environment. The visual stimuli of the stairs and shoes, provided by head-mounted displays, evoke a visuo-haptic interaction that modifies a user's perception of the floor shape. Our system enables users to experience all types of stairs, such as half-turn and spiral stairs, in a VR setting. We conducted a preliminary user study and two experiments to evaluate the proposed technique. The preliminary user study investigated the effectiveness of the basic idea associated with the proposed technique for the case of a user ascending stairs. The results demonstrated that the passive haptic feedback produced by the small bumps enhanced the user's feeling of presence and sense of ascending. We subsequently performed an experiment to investigate an improved viewpoint manipulation method and the interaction of the manipulation and haptics for both the ascending and descending cases. The experimental results demonstrated that the participants had a feeling of presence and felt a steep stair gradient under the condition of haptic feedback and viewpoint manipulation based on the characteristics of actual stair walking data. However, these results also indicated that the proposed system may not be as effective in providing a sense of descending stairs without an optimization of the haptic stimuli. We then redesigned the shape of the small bumps, and evaluated the design in a second experiment. The results indicated that the best shape to present haptic stimuli is a right triangle cross section in both the ascending and descending cases. Although it is necessary to install small protrusions in the determined direction, by using this optimized shape the users feeling of presence of the stairs and the sensation of walking up and down was enhanced.

Sol-gel transition accelerated by the co-assembly of two components in supramolecular hydrogels.

N-Palmitoyl-Gly-His (PalGH) and glycerol 1-monopalmitate (GMP) in water co-assembled into fibrils with twisted ribbon structures and formed a homogeneous network, resulting in gel formation. Shaking the gel easily broke the fibril network leading to a sol in which high and low fibril density regions exist. After a period at room temperature, the higher density regions became interconnected. The spontaneous sol-gel transition did not take place for a gel made from only PalGH. Also, during the transition, the aggregation state of the co-assembly remained unchanged at a molecular level, unlike the fibril network. Thus, it can be claimed that the sol-gel transition is not associated with the assembled molecular configuration, but with the change in the fibril network. This knowledge might be useful for understanding and controlling sol-gel transition, thereby leading to the design and functionalization of hydrogels.

Evaluation and management of plaque protrusion or thrombus following carotid artery stenting.

Carotid artery stenting (CAS) has become a common treatment for carotid artery stenosis. However, complications, such as an ischemic event, can occur with CAS during intra- and post-operative periods. Among these ischemic complications, plaque protrusion into the stent and thrombus on the stent have occurred after CAS. We retrospectively evaluated the temporal profile and treatment options for these complications in 32 consecutive cases who underwent CAS at our hospital between April 2009 and December 2011. The cases were evaluated pre-operatively for risk factors, as well as the plaque morphology and characteristics using computed tomographic angiography (CTA), ultrasound (US), and magnetic resonance imaging (MRI). Post-operatively, lesions were examined by CTA and/or US within 1 week of CAS. As a result, among the 32 cases, 8 experienced plaque protrusions or thrombus, which were treated with medication (anti-platelet and/or anti-coagulation reinforcement). In 7 of these 8 cases, the plaque protrusion or thrombus was stabilized with medication alone. However, the remaining case showed growth and migration of the plaque protrusion or thrombus when treated with medication alone, and therefore, required further endovascular treatment. We identified that a history of symptomatic cerebral infarction and plaques with ulceration were risk factors for plaque protrusion or thrombus formation after CAS, and pre dilatation can decrease the risk of these complications. Medication was effective in most cases of plaque protrusion or thrombus; however, further endovascular treatment was required when medication alone was unsuccessful.

Modulation of physical properties of supramolecular hydrogels based on a hydrophobic core.

We demonstrate herein the variation in viscoelastic properties of supramolecular hydrogels (SMGs) composed of two amphiphiles, N-Palmitoyl-Gly-His (PalGH) and sodium palmitate (PalNa). PalGH molecules in water form lamellar-like assemblies, which stack into sheet-shaped aggregates, resulting in the evolution of three-dimensional network structures. Once PalNa is added to PalGH, the alkyl groups of PalNa incorporate themselves into the hydrophobic cores of PalGH lamellar-like assemblies, resulting in a change in the assembly from lamellar-like to fibrous micelle-like. Consequently, sheet-shaped aggregates turn into flexible fibrils, which form bundles, resulting in network structures. Mixed hydrogel network structures differ in morphology from those in homogenous PalGH and PalNa hydrogels. Changes in the network structure eventually alter the bulk viscoelastic properties of hydrogels. These results demonstrate that the viscoelastic properties of supramolecular hydrogels can be tuned by controlling the aggregation states.

[Effective thrombolytic therapy for calcified cerebral embolism originating from a calcified plaque in the internal carotid artery].

A 72-year-old man was transported to our emergency department after rear-ending another vehicle. He presented with acute left hemispatial neglect, left hemianopsia, and mild left hemiparesis. Computed tomography (CT) on admission showed a calcified embolus in the right middle cerebral artery. After intravenous thrombolytic therapy, the patient showed drastic improvement of neurological deficits. Follow-up CT showed disappearance of embolus, but distal migration of emboli to the downstream of the right middle cerebral artery was seen, sparing the massive territory of the right middle cerebral artery. Carotid duplex sonography and 3-dimensional CT angiography showed a calcified plaque with ulceration at the origin of the right internal carotid artery, representing the presumptive origin of the emboli. We report a rare case of effective intravenous thrombolysis for calcified cerebral embolism from the carotid artery. Further consideration of the mechanism, efficacy, and indication of intravenous thrombolysis for calcified cerebral emboli is needed.

A new technique for the mapping of oxygen tension on the brain surface.

Most measurements of oxygen tension (PO(2)) in the brain have been performed using oxygen microelectrodes. However, the insertion of microelectrodes into the brain per se causes cortical injury and hence could lead to erroneous PO(2) measurements. The recently developed "quenching lifetime method" requires the injection of fluorescent chemicals into the blood circulation. To address this issue, we tested the feasibility of our O(2)-sensitive fluorescent membrane technique in the rat brain, and visualized the spatial distribution of PO(2) on the brain surface as epifluorescent microscopic patterns. An O(2)-quenching fluorescence dye, tris (1,10-phenanthroline) Ru(2+), was immobilized in a highly gas-permeable, thin silicone-rubber film formed on a microscope coverslip. Unlike the original method, which was intended for transparent rat mesenteric tissue, any change in the redox state in the brain tissue will influence the optical measurement of PO(2). Thus, in the present study, the O(2)-sensing membrane was further coated with a thin opaque silicone-rubber to minimize this type of influence. This new method enabled us to visualize the PO(2) gradient on the rat brain without causing cortical injuries. In an ischemia/reperfusion model using Pulsinelli's four-vessel occlusion rats, the changes in the PO(2) were highly heterogeneous during the ischemic period and this heterogeneity, both temporal and spatial, was higher in the off-arteriolar area than in the peri-arteriolar area.

Endovascular treatment of vertebral artery aneurysm manifesting as progressive hemifacial spasm.

A 62-year-old woman presented with right hemifacial spasm persisting for 6 months. Brain magnetic resonance imaging and digital subtraction angiography showed a wide-neck aneurysm of the intracranial portion of the right vertebral artery. The patient underwent endovascular trapping of the aneurysm by coil embolization of the parent vessel on both sides of the aneurysm. The patient experienced gradual disappearance of the hemifacial spasm within 3 months. No relapses occurred during a follow-up period of 3 years. Magnetic resonance imaging revealed shrinkage of the vertebral artery aneurysm which had compressed the facial nerve. Endovascular trapping of a vertebral artery aneurysm can be used to treat hemifacial spasm caused by an aneurysm instead of surgical microvascular decompression.