Anti-myelin Oligodendrocyte Glycoprotein Antibody-positive Myelitis after Coronavirus Disease 2019.

We herein report a case of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-related myelitis caused by coronavirus disease (COVID-19) infection in 2021. A 22-year-old man with no history of any related illness contracted COVID-19. Eight days later, he developed bladder problems, paraplegia and sensory disturbances. Cervical spinal cord magnetic resonance imaging revealed extensive hyperintensity at T2 and spinal cord lesions extending from C4 to Th1. The patient was diagnosed with transverse myelitis and started on intravenous methylprednisolone, plasma exchange and intravenous immunoglobulin therapy. The symptoms improved only after intravenous methylprednisolone therapy. Anti-MOG antibodies were found in his serum and cerebrospinal fluid during routine screening. As this observation is unusual and could cause serious health problems, we wonder if COVID-19 triggered this autoimmune response.

Paraneoplastic cerebellar degeneration with anti-Yo antibodies and an associated submandibular gland tumor: a case report.

BACKGROUND: As a debilitating syndrome, paraneoplastic cerebellar degeneration (PCD) remains challenging to treat. Further, anti-Yo antibody (directed against human cerebellar degeneration-related protein 2) detection in patients with PCD is associated with unsatisfactory responses to existing therapies. Here, we present the case of a 60-year-old woman who developed PCD with anti-Yo antibodies and a submandibular gland tumor. CASE PRESENTATION: A 60-year-old woman presented with a 5-day history of unsteadiness of gait and inadequate coordination of her extremities, along with truncal instability. Although walking without aid was possible, dysmetria of all four limbs, trunk, and gait ataxia was observed. While routine biochemical and hematological examinations were normal, the patient's blood was positive for anti-Yo antibodies. When the neurological symptoms deteriorated despite administration of intravenous methylprednisolone, fluorodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) images with contrast enhancement were performed, which showed a tumor in the left submaxillary gland. She underwent total left submandibular gland resection, including the tumor; histological and immunohistochemical results revealed a salivary duct carcinoma. She was administered intravenous methylprednisolone, followed by 10 plasma exchange sessions, intravenous immunoglobulins, and cyclophosphamide therapy. Following treatment, her symptoms were not alleviated, even after the reduction of anti-Yo titers. CONCLUSIONS: Although tumor detection was delayed, early tumor detection, diagnosis, and PCD treatment are essential because any delay can result in the progression of the disorder and irreversible neurological damage. Therefore, we recommend that the possibility of a salivary gland tumor should be considered, and whole-body dual-modality CT, including the head and neck, and FDG-PET should be performed at the earliest for patients with well-characterized paraneoplastic antibodies when conventional imaging fails to identify a tumor.

Electrostrictive and Piezoelectric Effects in Relaxor Ferroelectrics: Historical Background.

Electrostrictive effects in complex-perovskite "relaxor" ferroelectrics (FEs) exhibit superior performance in comparison with the simple-perovskite normal FEs, such as giant electrostriction in its paraelectric phase and high electromechanical coupling in its FE phase. As one of the discoverers, the author will deliver the historical background of these epoch-making phenomena and the development strategy of how we considered performance improvement. Though both discoveries were actually originated from a sort of "serendipity" (lucky & accidental occurrence!), some of the key factors have been embedded in the research base: 1) interrelation between complex perovskite structure and ferroelectricity; 2) anharmonicity in relaxor FEs; and 3) microdomain contribution in relaxor FEs. In the last part of this article, the author introduces a bit different "mesoscopic" approach, "fractal analysis of microdomain configuration" in conjunction with the "domain engineering" concept, to distinguish the electromechanical coupling among the normal and relaxor FEs for remaining the future research seeds.

[A case of meningoencephalitis that developed during nivolumab use].

A 72-year-old woman developed a fever and consciousness disturbance after completing 8 courses of nivolumab for lung adenocarcinoma. A cerebrospinal fluid test showed an increased cell count, but bacterial culture, herpes simplex virus-polymerase chain reaction, acid-fast staining, and cytology were negative; serum paraneoplastic syndrome-related antibody was also negative. Serum and cerebrospinal fluid specimens were positive for anti-glutamate receptor (GluR) antibody, and fluid-attenuated inversion recovery images on head magnetic resonance imaging showed a high signal intensity at the right parietal lobe. The condition was determined to be immune-mediated encephalitis, and pulse steroid therapy was performed. The symptoms promptly improved after treatment. The patient in the present case was anti-GluR antibody-positive but was determined to have nivolumab-related encephalitis based on the clinical course. The use of immune checkpoint inhibitors has become widespread in recent years, although it can occasionally lead to encephalitis. We herein report our experience with immune checkpoint inhibitor-related encephalitis, which is seldom reported in Japan.

The Risk Factors for Death within 6 Months After Ischemic Stroke in Patients with Cancer.

OBJECTIVES: While the intravenous recombinant tissue plasminogen activator (rt-PA) therapy for acute ischemic stroke patients with cancer is recommended when survival of ≥ 6 months is expected, the risk factors for death and stroke recurrence within 6 months after stroke are not well known. Thus, we aimed to identify markers for death and recurrence risks within six months from stroke onset in patients with cancer. MATERIALS AND METHODS: In a retrospective cohort study, the subjects comprised acute ischemic stroke patients with cancer hospitalized at St. Marianna University hospital from 2008 through 2019. To evaluate the associations between the clinical factors within 24 h of the initial stroke and death or stroke recurrence events within 6 months from stroke onset, Logistic analysis and Cox proportional hazards regression analysis was used respectively. Next, the optimal cutoff point of markers for different mortality groups was determined using the receiver operating characteristic curve analysis and cumulative outcome rate of each group was compared using the Kaplan-Meier method. RESULTS: Among 194 patients with cancer who developed acute stroke, 167 were ultimately selected for analysis. 47 subjects (28.14%) passed away within 6 months following stroke onset, and 20 subjects (11.98%) had stroke recurrence. High D-dimer levels, low fibrinogen levels, high Glasgow prognostic scores (GPS), and multiple vascular territory infarctions was independently associated with death, where higher death rate was significantly confirmed in the group with D-dimer levels of ≥3.95 mg/dl, fibrinogen levels <277.5 mg/dl and GPS scores of 2. Low fibrinogen level, lack of antithrombotic therapy, and the presence of metastasis were associated with stroke recurrence. CONCLUSIONS: When patients with cancer suffer stroke, D-dimer levels, fibrinogen levels, GPS, and multiple vascular territory infarctions would be associated with the risk of death within 6 months. Low fibrinogen levels, lack of antithrombotic therapy, and the presence of metastasis correlated with high risk of stroke recurrence.

Nonbacterial Thrombotic Endocarditis Complicated by Cerebral Infarction in a Patient with Adenomyosis with High Serum CA125 Level; A Case Report.

We report a case of a 48-year-old woman with multiple cerebral infarctions caused by nonbacterial thrombotic endocarditis (NBTE) because of adenomyosis with high serum carbohydrate antigen (CA)125 level. Transesophageal echocardiography (TEE) showed a vegetation, 4 mm in diameter, adjacent to the anterior leaflet of the mitral valve on day 2. Soluble CA125 level was elevated to 901 U/mL. Intravenous infusion of unfractionated heparin sodium was started. On day 35, TEE revealed reduction of the vegetation in size, 2 mm in diameter. On day 38, she was transferred to the hospital for further rehabilitation. CA125 is a transmembrane mucin that contributes to the progression of epithelial ovarian cancer. It is important to keep in mind that adenomyosis with abnormally high serum CA125 level may be at high risk of NBTE.

Impact of inability to turn in bed assessed by a wearable three-axis accelerometer on patients with Parkinson's disease.

BACKGROUND: Difficulty turning over in bed is a common night-time symptom in Parkinson's disease (PD). We aimed to quantitatively evaluate overnight turnover movements using a three-axis accelerometer and to investigate whether inability to turn in bed is related to daytime sleepiness, sleep quality, and depressive mood in PD patients. METHODS: We examined 64 patients with PD (mean age, 73.3±8.21 years; modified Hoehn-Yahr [mH-Y] stage, 3.0±1.0; disease duration, 7.2±6.3 years; unified Parkinson's disease rating scale [UPDRS], 36.9±18.3). Overnight monitoring of turnover movements using a wearable three-axis accelerometer was performed in all patients. Nocturnal kinetic parameters including total time recumbent, total time supine, number of turnover movements, and mean interval between turnover movements were obtained. Daytime immobility was assessed using the Barthel index (B-I), UPDRS, and mH-Y stage. Patients were also assessed with the Epworth Sleepiness Scale (ESS), Parkinson's Disease Sleep Scale-2 (PDSS-2), and Beck Depression Inventory (BDI). RESULTS: Number of turnover movements in bed correlated negatively with disease duration (r = -0.305; p<0.05), L-dopa-equivalent dose (r = -0.281; p<0.05), mH-Y staging (r = -0.336; p<0.01), total score of UPDRS (r = -0.386; p<0.01) and positively with B-I score (r = 0.365; p<0.01). Number of turnover movements in bed was generally inconsistent with awareness of turnover movement impairment as evaluated by PDSS-2 Item 9 scores, but patients who were never aware of impaired turnover movements showed ≥5 turnover movements overnight. Multivariate logistic regression analyses revealed no correlations between number of nocturnal turnover movements in bed and BDI, ESS, or PDSS-2. Use of anti-psychotic drugs was associated with ESS (p = 0.045). UPDRS was associated with PDSS-2 (p = 0.016). CONCLUSION: Decreased number of turnover movements may not be a direct determinant of daytime sleepiness, sleep disorders, or depressive mood in PD patients. Use of anti-psychotic drugs and higher UPDRS score are factors significantly associated with daytime sleepiness and uncomfortable sleep, respectively.

Utility of Duranta, a wireless patch-type electrocardiographic monitoring system developed in Japan, in detecting covert atrial fibrillation in patients with cryptogenic stroke: A case report.

RATIONALE: Subcutaneous implantable electrocardiographs are highly effective in detecting covert atrial fibrillation (AF) in cryptogenic stroke. However, these invasive devices are not indicated for all cryptogenic stroke patients, and noninvasive improvements over conventional Holter-type ambulatory electrocardiography are needed. We evaluated the clinical application and effectiveness of Duranta (ImageONE Co., Ltd.), a wireless patch-type electrocardiographic monitoring system developed in Japan for chronically ill patients or home-based patients at the end of life. A Duranta device was used to detect covert AF in patients with acute ischemic stroke of undetermined source with no sign of AF during cardiographic monitoring ≥24 hours postadmission. PATIENT CONCERNS: A 72-year-old man with severe aortic stenosis was admitted to our hospital with dysarthria and right upper limb weakness. Diffusion-weighted plain head magnetic resonance imaging (MRI) showed acute cerebral infarctions across the left middle cerebral artery territory. Twelve-lead electrocardiography, Holter-type ambulatory electrocardiography, and cardiographic monitoring for ≥24 hours revealed no AF, indicating a probable diagnosis of artery-to-artery embolism following left common carotid artery stenosis detected by carotid ultrasound imaging and cerebral angiography. INTERVENTIONS: However, because of high blood brain natriuretic peptide (BNP) and valvular heart disease, continuous monitoring using Duranta was performed from the 2nd to 13th days after onset to exclude possible cardioembolic stroke. Waveform and heart rate trend graph analysis showed paroxysmal AF (PAF) occurred on the 5th and 9th days after onset. PAF did not occur at any other time during the observation period. The quality of the cardiograms sufficed for analysis and diagnosis of AF. The lightweight compact device can be placed quickly with no movement restriction. These features and our findings show the usefulness of the Duranta device for long-term continuous monitoring. LESSONS: A noninvasive wireless patch-type electrocardiographic monitoring system, Duranta, placed at the precordium, was useful in detecting covert AF in cryptogenic stroke patients, warranting further investigation.

Single-phase driven ultrasonic motor using two orthogonal bending modes of sandwiching piezo-ceramic plates.

A compact ultrasonic motor using sandwiching piezo-ceramic plates was developed, having advantages of low manufacturing costs, simple driving circuit, and high scalability. The stator is composed of two piezoelectric plates attached to a T-shaped steel body. Two orthogonal bending modes can be excited by driving one piezoelectric plate and the reversed motion of the rotor can be obtained by driving the piezoelectric plate on the opposite side. The prototype stator with a size of 15 mm × 2.44 mm × 2 mm, operated at 44.8 kHz, was experimentally characterized, and a maximum torque of 2 mN m was obtained. Maximum power of 2.3 mW and efficiency of 9% were produced with a load of 0.8 mN m at a rotation speed of 27 rpm.

Driving frequency optimization of a piezoelectric transducer and the power supply development.

Piezoelectric transducers are commonly operated at their resonance frequency. However, from a power dissipation standpoint, this is not the ideal driving frequency. In this paper, an optimized driving frequency in between the resonance and antiresonance frequencies is proposed for the piezo-transducer. First, the optimum driving frequency is characterized using a constant vibration velocity measurement method. The actual input power reveals the lowest power dissipation frequency between the resonance and the antiresonance frequencies, where the transducer behaves inductive. The electrical parameters of the transducer are then determined by an equivalent circuit formulation, which is useful for the electrical circuit analysis of the driver design. A Class E resonant inverter is used to design a capacitive output impedance driver at the optimized frequency by utilizing a series capacitor. Compared with the traditional resonance drive, driving at the optimized frequency reduces the required power by approximately half according to the measurements performed.

Characteristics of Symptomatic Intracranial Hemorrhage in Patients Receiving Non-Vitamin K Antagonist Oral Anticoagulant Therapy.

OBJECTIVES: The first non-vitamin K antagonist oral anticoagulant (NOAC) introduced to the market in Japan was dabigatran in March 2011, and three more NOACs, rivaroxaban, apixaban, and edoxaban, have since become available. Randomized controlled trials of NOACs have revealed that intracranial hemorrhage (ICH) occurs less frequently with NOACs compared with warfarin. However, the absolute incidence of ICH associated with NOACs has increased with greater use of these anticoagulants, and we wanted to explore the incidence, clinical characteristics, and treatment course of patients with NOACs-associated ICH. METHODS: We retrospectively analyzed the characteristics of symptomatic ICH patients receiving NOACs between March 2011 and September 2014. RESULTS: ICH occurred in 6 patients (5 men, 1 woman; mean ± SD age, 72.8 ± 3.2 years). Mean time to onset was 146.2 ± 111.5 days after starting NOACs. Five patients received rivaroxaban and 1 patient received apixaban. None received dabigatran or edoxaban. Notably, no hematoma expansion was observed within 24 h of onset in the absence of infusion of fresh frozen plasma, activated prothrombin complex concentrate, recombinant activated factor VIIa or hemodialysis. When NOAC therapy was initiated, mean HAS-BLED and PANWARDS scores were 1.5 ± 0.5 and 39.5 ± 7.7, respectively. Mean systolic blood pressure was 137.8 ± 15.9 mmHg within 1 month before spontaneous ICH onset. CONCLUSION: Six symptomatic ICHs occurred early in NOAC therapy but hematoma volume was small and did not expand in the absence of infusion of reversal agents or hemodialysis. The occurrence of ICH during NOAC therapy is possible even when there is acceptable mean systolic blood pressure control (137.8 ± 15.9 mmHg) and HAS-BLED score ≤ 2. Even stricter blood pressure lowering and control within the acceptable range may be advisable to prevent ICH during NOAC therapy.

Glory of piezoelectric perovskites.

This article reviews the history of piezoelectric perovskites and forecasts future development trends, including Uchino's discoveries such as the Pb(Mg1/3Nb2/3)O3-PbTiO3 electrostrictor, Pb(Zn1/3Nb2/3)O3-PbTiO3 single crystal, (Pb, La)(Zr, Ti)O3 photostriction, and Pb(Zr, Ti)O3-Terfenol magnetoelectric composites. We discuss five key trends in the development of piezomaterials: performance to reliability, hard to soft, macro to nano, homo to hetero, and single to multi-functional.

Consideration of impedance matching techniques for efficient piezoelectric energy harvesting.

This study investigates multiple levels of impedance-matching methods for piezoelectric energy harvesting in order to enhance the conversion of mechanical to electrical energy. First, the transduction rate was improved by using a high piezoelectric voltage constant (g) ceramic material having a magnitude of g33 = 40 x 10(-3) V m/N. Second, a transducer structure, cymbal, was optimized and fabricated to match the mechanical impedance of vibration source to that of the piezoelectric transducer. The cymbal transducer was found to exhibit approximately 40 times higher effective strain coefficient than the piezoelectric ceramics. Third, the electrical impedance matching for the energy harvesting circuit was considered to allow the transfer of generated power to a storage media. It was found that, by using the 10-layer ceramics instead of the single layer, the output current can be increased by 10 times, and the output load can be reduced by 40 times. Furthermore, by using the multilayer ceramics the output power was found to increase by 100%. A direct current (DC)-DC buck converter was fabricated to transfer the accumulated electrical energy in a capacitor to a lower output load. The converter was optimized such that it required less than 5 mW for operation.

Analytical solutions for the transverse deflection of a piezoelectric circular axisymmetric unimorph actuator.

This paper presents analytical solutions to the transverse deformation shape of a circular axisymmetric piezoelectric-metal composite unimorph actuator. The solutions account for both the influence of an applied electric field and a concentrated or uniformly distributed mechanical load. Using piezoelectric constitutive equations, combined with thin plate and small bending elastic theory, the generalized equation of motion for bending of thin piezoelectric-metal composite plates has been derived. Our approach predicts that there is an optimum thickness ratio between the piezoelectric and metal plates, which leads to a maximum combination of deflection and load carrying capabilities. Derived formulas are very simple that offer a quick method for engineering design and optimization of a circular unimorph piezoelectric actuator.

High power universal piezoelectric transformer.

This study describes a multilayer piezoelectric voltage and power transformer that has one direction poling, operates in a wide-frequency range and delivers both step-up and step-down voltages by inverting the electrical connections. In this design, the input and output electrodes are on the same side of the disk and are isolated from each other by a fixed isolation gap. The electrode pattern is a ring/dot structure such that it uses radial mode for both input and output part that are built-in on the same ceramic disk. A prototype transformer was fabricated of size 15 x 2.78 mm2 having mass of 3.8 gm. In the step-down configuration at the constant output power of 6 W, the transformer characteristics across a 100 ohms load were found to be efficiency = 92%, gain = 0.21 input voltage = 110 Vrms, and temperature rise = 20 degrees C from the room temperature. In the step-up configuration at the constant output power of 5 W, the transformer characteristics across a 5 kohms load were found to be efficiency = 97%, gain = 9.5, input voltage = 16 Vrms, and temperature rise = 8 degrees C from the room temperature. A detailed equivalent circuit analysis of the transformer was done, and the results were found to be in excellent agreement with the experimental results.

An accurate method for the determination of complex coefficients of single crystal piezoelectric resonators I: theory.

This paper presents the theoretical derivation for a method of accurately determining the complex coefficients of single crystal piezoelectric materials. The vibration equations are analytically solved for a piezoelectric plate and a piezoelectric thin rod in an arbitrary crystallographic orientation. The solutions provide the distributions of the stresses and the vibration velocities inside the sample and the electrical impedance between the electrodes. Based on the analysis of the solutions, the complex dielectric, elastic, and piezoelectric coefficients are determined from the impedance or admittance measurements near the resonance frequencies. The measurement for LiNbO3 single crystals is used as an example to demonstrate the experiment and calculation procedures and to indicate the comparisons with previous methods.

An accurate method for the determination of complex coefficients of single crystal piezoelectric resonators II: design of measurement and experiments.

In this paper, we present the design of measurements for single crystals by using the general results in Part I of this paper. The selection of impedance measurement or admittance measurement for both bar and plate type resonators is dependent on whether the cutting orientation l is parallel to or perpendicular to the electric field direction n. Two matrices A and B, which are defined in part I of this paper, are major tools used for the measurement design. For different cutting orientations, the elements in matrix A are associated with different elastic and piezoelectric constants. Matrix B reveals what vibration modes can be excited electrically and how to excite them. With the aid of matrices A and B, the design of measurement becomes straightforward. The measurement for a rhombohedral class (3m) LiNbO3 single crystal is used as an example to demonstrate the experiment and calculation procedures. It is found that by using either three thin bars and one plate or three plates and one thin bar we can completely characterize the complex materials constants of a LiNbO3 single crystal.

A 1.6-mm, metal tube ultrasonic motor.

A miniaturized metal tube ultrasonic motor, the dimensions of which are 1.6 mm in diameter and 6 mm in length, was developed. Two flattened surfaces with 90-degrees were ground on the outer surface of the stator. Two PZT-based piezoelectric ceramics were bonded onto these flat surfaces. The asymmetrical surface of the stator developed the split of the two degenerated orthogonal bending modes, resulting in a wobble motion. The working frequency of the 1.6-mm motor with 6 mm in length was 130 kHz. A torque of 0.5 mNm was reached at a maximum power of 45 mW with a speed of 45 rad/sec. The maximum efficiency was 16%.

Piezoelectric ultrasonic micromotor with 1.5 mm diameter.

A piezoelectric ultrasonic micromotor has been developed using a lead zirconate titanate (PZT) ceramic/metal composite tube stator that was 1.5 mm in diameter and 7 mm in length. The micromotor was operated in its first bending vibration mode (approximately 70 kHz), producing speeds from hundreds to over 2000 rpm in both rotational directions. The maximum torque-output was 45 microN-m, which is far superior to previous PZT thin film-based micromotors. This micromotor showed good reliability and stability for more than 300 hours of continued operation.

Accurate determination of complex materials coefficients of piezoelectric resonators.

This paper presents a method of accurately determining the complex piezoelectric and elastic coefficients of piezoelectric ceramic resonators from the measurement of the normalized electric admittance, Y, which is electric admittance Y of piezoelectric resonator normalized by the angular frequency omega. The coefficients are derived from the measurements near three special frequency points that correspond to the maximum and the minimum normalized susceptance (B) and the maximum normalized conductance (G). The complex elastic coefficient is determined from the frequencies at these points, and the real and imaginary parts of the piezoelectric coefficient are related to the derivative of the susceptance with respect to the frequency and the asymmetry of the conductance, respectively, near the maximum conductance point. The measurements for some lead zirconate titanate (PZT) based ceramics are used as examples to demonstrate the calculation and experimental procedures and the comparisons with the standard methods.