Usefulness of thermography for differentiating Wallenberg's syndrome from noncentral vertigo in the acute phase.

OBJECTIVES: Wallenberg's syndrome (WS) is caused by a stroke in the lateral medulla and can present with various symptoms. One of the main symptoms is vertigo, which can be misdiagnosed as noncentral vertigo (NCV). Approximately 90% of the patients with acute WS have a lateral difference in body surface temperature (BST) due to autonomic pathway disturbances from infarction. Additionally, thermography can aid in WS diagnosis; however, whether BST differences occur in patients with acute NCV is unclear. METHODS: This study used thermography to measure the BST of patients with NCV and acute WS to determine the effectiveness of BST to differentiate between the conditions. Forty-eight consecutive patients diagnosed with NCV whose BST was measured using thermography during a hospital visit or admission were enrolled. The left and right BST of four sites (face, trunk, and upper and lower limbs) were measured and compared with obtained BST of nine patients with WS. RESULTS: Twenty-two patients had lateral differences in BST ≥ 0.5°C, three with ≥1.5°C, and none with ≥2.5°C. Only one patient with NCV had lateral differences in BST at two or more ipsilateral sites. When WS differentiated from NCV, a left-right difference ≥0.5°C in two or more ipsilateral sites had a sensitivity of 89% and specificity of 98%, and ≥1.0°C had a sensitivity of 78% and specificity of 98%. DISCUSSION: Acute WS can be differentiated from NCV through BST and the number of sites with lateral differences via thermography, even in rooms where conditions are unregulated.

Fundamental study on diagnostic reference level quantities for endoscopic retrograde cholangiopancreatography using a C-arm fluoroscopy system.

The diagnostic reference level (DRL) is an effective tool for optimising protection in medical exposures to patients. However regarding air kerma at the patient entrance reference point (Ka,r), one of the DRL quantities for endoscopic retrograde cholangiopancreatography (ERCP), manufacturers use a variety of the International Electrotechnical Commission and their own specific definitions of the reference point. The research question for this study was whetherKa,ris appropriate as a DRL quantity for ERCP. The purpose of this study was to evaluate the difference betweenKa,rand air kerma incident on the patient's skin surface (Ka,e) at the different height of the patient couch for a C-arm system. Fluoroscopy and radiography were performed using a C-arm system (Ultimax-i, Canon Medical Systems, Japan) and a over-couch tube system (CUREVISTA Open, Fujifilm Healthcare, Japan).Ka,ewas measured by an ion chamber placed on the entrance surface of the phantom. Kerma-area product (PKA) andKa,rwere measured by a built-inPKAmeter and displayed on the fluoroscopy system.Ka,edecreased whileKa,rincreased as the patient couch moved away from the focal spot. The uncertainty of theKa,e/Ka,rratio due to the different height of the patient couch was estimated to be 75%-94%.Ka,rmay not accurately representKa,e.PKAwas a robust DRL quantity that was independent of the patient couch height. We cautioned against optimising patient doses in ERCP with DRLs set in terms ofKa,rwithout considering the patient couch height of the C-arm system. Therefore, we recommend thatKa,ris an inappropriate DRL quantity in ERCP using the C-arm system.

[Relative Error between Organ Doses and Size-specific Dose Estimates for a Specific Location When the Mean CTDIvol Value Is Used for Calculation].

Size-specific dose estimates (SSDEs) are dose indices that account for differences in body shape in computed tomography (CT) scans, allowing the evaluation of approximate absorbed doses in any cross section that could not be obtained with the volume CT dose index (CTDIvol). When using automatic exposure control (AEC), CTDIvol is modulated in the body axis direction, but the value displayed after the examination is the mean CTDIvol for the entire scan, and it is expected that the SSDE value will change depending on which value is used in the calculation. In this study, using a human body phantom, we examined the influence of whether the mean CTDIvol or the modulation value for each slice is used to calculate the SSDE on local organ dose evaluation. A program to calculate water equivalent diameter according to the procedure in the American Association of Physicists in Medicine Report No. 220 was developed and compared. As a result, SSDE calculated using the mean CTDIvol (local-SSDEmean) overestimated organ doses in the lung region by 18%-56% compared with those calculated by a web system for evaluating CT exposure doses (WAZA-ARIv2, Japan). In contrast, local-SSDEmodulated, which was calculated using the modulated value of the CTDIvol, was able to estimate the organ dose with a relative error of 10%-13%. The average local-SSDE over the entire body axis direction was not significantly different between the two methods, regardless of which method was used for CTDIvol. If the mean CTDIvol is stored in the Digital Imaging and Communications in Medicine (DICOM) header tag (0018, 9345) of the CT image and the modulated CTDIvol value is not available for each slice, the calculated local SSDE will contain many errors and will not correctly reflect the organ doses at the scan region. In such cases, it is available to use the method of evaluating local organ doses by multiplying the SSDE, which is the average of the SSDE for the entire scan, by a factor for each organ.

Detection of ictal and periictal hyperperfusion with subtraction of ictal-interictal 1.5-Tesla pulsed arterial spin labeling images co-registered to conventional magnetic resonance images (SIACOM).

Background: Our recent report showed that 1.5-T pulsed arterial spin labeling (ASL) magnetic resonance (MR) perfusion imaging (1.5-T Pulsed ASL [PASL]), which is widely available in the field of neuroemergency, is useful for detecting ictal hyperperfusion. However, the visualization of intravascular ASL signals, namely, arterial transit artifact (ATA), is more remarkable than that of 3-T pseudocontinuous ASL and is easily confused with focal hyperperfusion. To eliminate ATA and enhance the detectability of (peri) ictal hyperperfusion, we developed the subtraction of ictal-interictal 1.5-T PASL images co-registered to conventional MR images (SIACOM). Methods: We retrospectively analyzed the SIACOM findings in four patients who underwent ASL during both (peri) ictal and interictal states and examined the detectability for (peri) ictal hyperperfusion. Results: In all patients, the ATA of the major arteries was almost eliminated from the subtraction image of the ictal-interictal ASL. In patients 1 and 2 with focal epilepsy, SIACOM revealed a tight anatomical relationship between the epileptogenic lesion and the hyperperfusion area compared with the original ASL image. In patient 3 with situation-related seizures, SIACOM detected minute hyperperfusion at the site coinciding with the abnormal electroencephalogram area. SIACOM of patient 4 with generalized epilepsy diagnosed ATA of the right middle cerebral artery, which was initially thought to be focal hyperperfusion on the original ASL image. Conclusion: Although it is necessary to examine several patients, SIACOM can eliminate most of the depiction of ATA and clearly demonstrate the pathophysiology of each epileptic seizure.

Spatial Scattering Radiation to the Radiological Technologist during Medical Mobile Radiography.

Mobile radiography allows for the diagnostic imaging of patients who cannot move to the X-ray examination room. Therefore, mobile X-ray equipment is useful for patients who have difficulty with movement. However, staff are exposed to scattered radiation from the patient, and they can receive potentially harmful radiation doses during radiography. We estimated occupational exposure during mobile radiography using phantom measurements. Scattered radiation distribution during mobile radiography was investigated using a radiation survey meter. The efficacy of radiation-reducing methods for mobile radiography was also evaluated. The dose decreased as the distance from the X-ray center increased. When the distance was more than 150 cm, the dose decreased to less than 1 µSv. It is extremely important for radiological technologists (RTs) to maintain a sufficient distance from the patient to reduce radiation exposure. The spatial dose at eye-lens height increases when the bed height is high, and when the RT is short in stature and abdominal imaging is performed. Maintaining sufficient distance from the patient is also particularly effective in limiting radiation exposure of the eye lens. Our results suggest that the doses of radiation received by staff during mobile radiography are not significant when appropriate radiation protection is used. To reduce exposure, it is important to maintain a sufficient distance from the patient. Therefore, RTs should bear this is mind during mobile radiography.

A case of Miller Fisher syndrome with delayed onset peripheral facial nerve palsy after COVID-19 vaccination: a case report.

BACKGROUND: To prevent the spread of the novel coronavirus disease 2019 (COVID-19) infection, various vaccines have been developed and used in a large number of people worldwide. One of the most commonly used vaccines is the mRNA vaccine developed by Moderna. Although several studies have shown this vaccine to be safe, the full extent of its side effects has not yet been known. Miller-Fisher syndrome (MFS) is a rare condition that manifests ophthalmoplegia, ataxia, and loss of tendon reflexes. It is a subtype of Guillain-Barré syndrome and an immune-mediated disease related to serum IgG anti-GQ1b antibodies. Several vaccines including those for COVID-19 have been reported to induce MFS. However, there have been no reports of MFS following Moderna COVID-19 vaccine administration. CASE PRESENTATION: A 70-year-old man was referred to our hospital due to diplopia that manifested 1 week after receiving the second Moderna vaccine dose. The patient presented with restricted abduction of both eyes, mild ataxia, and loss of tendon reflexes. He was diagnosed with MFS based on his neurological findings and detection of serum anti-GQ1b antibodies. The patient was administered intravenous immunoglobulin, and his symptoms gradually improved. Five days after admission, the patient showed peripheral facial paralysis on the right side. This symptom was suggested to be a delayed onset of peripheral facial nerve palsy following MFS that gradually improved by administration of steroids and antiviral drugs. CONCLUSION: There have been no previous reports of MFS after Moderna COVID-19 vaccination. This case may provide new information about the possible neurological side effects of COVID-19 vaccines.

A Rare Etiology for Ascending Paralysis in an Infant.

An 11-month-old male infant with ascending paralysis had an unremarkable initial cerebrospinal fluid (CSF) analysis and imaging. Progressive neurological symptoms resulted in repeated CSF sampling, microscopy, and plasma microbial cell-free DNA next-generation sequencing analysis, that in combination with epidemiology, confirmed the diagnosis.

Reversible right-sided heart failure and pulmonary hypertension caused by scurvy in a 7-year-old boy with autism spectrum disorder and a review of the literature.

Scurvy, a condition caused by vitamin C deficiency, is rare, especially in high-income countries. Symptoms of scurvy are typically characterised by dermatological disorders such as poor wound healing and tooth loss, but there is not usually cardiac involvement. A case of reversible pulmonary hypertension and right-sided heart failure owing to scurvy in a 7-year-old boy with autism spectrum disorder is reported. He had a very restricted diet and presented with polyarthralgia, gingival hyperplasia with ecchymosis, and fatigue. His condition, including pulmonary hypertension and right-sided heart failure, completely resolved with vitamin C supplementation. Paediatricians should have a high index of suspicion for scurvy in children with nutritional selectivity and be aware that it can manifest with cardiac symptoms. Scurvy may be life-threatening if not treated, but the symptoms can improve rapidly with vitamin C supplementation.

Mother and son cases of Bickerstaff's brainstem encephalitis and fisher syndrome with serum anti-GQ1b IgG antibodies: a case report.

BACKGROUND: Bickerstaff's brainstem encephalitis (BBE) and Fisher syndrome (FS) are immune-mediated diseases associated with anti-ganglioside antibodies, specifically the anti-GQ1b IgG antibody. These two diseases potentially lie on a continuous spectrum with Guillain-Barré Syndrome (GBS). There are some reports of family cases of GBS and fewer of FS. However, there are no reports of family cases of BBE and FS. CASE PRESENTATION: We report a familial case of an 18-year-old son who had BBE and his 52-year-old mother diagnosed with FS within 10 days. The son showed impaired consciousness 1 week after presenting with upper respiratory symptoms and was brought to our hospital by his mother. He showed decreased tendon reflexes, limb ataxia, albuminocytologic dissociation in his spinal fluid, and positive serum anti-GQ1b antibodies. Haemophilus influenzae was cultured from his sputum. He was diagnosed with BBE and treated with intravenous immunoglobulin (IVIg) therapy, which led to an improvement in symptoms. The mother presented with upper respiratory symptoms 3 days after her son was hospitalized. Seven days later, she was admitted to the hospital with diplopia due to limited abduction of the left eye. She showed mild ataxia and decreased tendon reflexes. Her blood was positive for anti-GQ1b antibodies. She was diagnosed with FS and treated with IVIg, which also led to symptomatic improvement. CONCLUSIONS: There are no previous reports of familial cases of BBE and FS; therefore, this valuable case may contribute to the elucidation of the relationship between genetic predisposition and the pathogenesis of BBE and FS.

Measuring Quality of Care for Ischemic Stroke Treated With Acute Reperfusion Therapy in Japan　- The Close The Gap-Stroke.

BACKGROUND: In Japan there is no consensus on how to efficiently measure quality indicators (QIs), defined as a standard of care, for acute ischemic stroke (AIS). Using information from a health insurance claims database and electronic medical records, we evaluated the feasibility and validity of measuring QIs for AIS patients who received intravenous recombinant tissue plasminogen activator (IV rt-PA) or endovascular therapy (EVT).Methods and Results:AIS patients receiving rt-PA or EVT between 2013 and 2015 were identified. We selected 17 AIS QI measures for primary stroke centers (PSCs) and 8 for comprehensive stroke centers (CSCs). Defined QIs were calculated for each hospital and then averaged. In total, the data of 8,206 patients (rt-PA 83.7%, EVT 34.9%) from 172 hospitals were obtained. Median National Institute of Health Stroke Scale score at admission was 14, and 37.7% of the patients were functionally independent at discharge. All target QIs were successfully measured with fewer missing values, and the accuracy of preset data was about 90%. Adherence rates were low (<50%) in 5 QI measures among PSCs, including door-to-needle time ≤1 h, and in 1 QI measure among CSCs (door-to-brain and vascular imaging time ≤30 min). CONCLUSIONS: Measuring QIs for AIS by this novel approach was feasible and reliable in the provision of a national benchmark.

Nab-Paclitaxel Followed by 5-Fluorouracil, Epirubicin and Cyclophosphamide in Neoadjuvant Chemotherapy for Resectable Breast Cancer: A Phase II Trial.

BACKGROUND: The aim of this phase II study was to evaluate combined nab-paclitaxel (nab-PTX) with sequential anthracycline-based therapy as a neoadjuvant chemotherapy. METHODS: We enrolled 41 patients with advanced breast cancer (stage IIA - IIIC). All patients were to receive three-weekly nab-PTX (260 mg/m2) for four cycles followed by three-weekly 5-fluorouracil, epirubicin and cyclophosphamide (FEC) for four cycles. Trastuzumab administration was permitted in human epidermal growth factor receptor 2 (HER2)-positive patients. RESULTS: The overall pathological complete response (pCR) rate was 24% (10 of 41). In patients with luminal A, luminal B (HER2-), luminal B (HER2+), triple-negative and HER2, the pCR rates were 0% (0/2), 7% (1/14), 42% (3/7), 25% (4/16) and 100% (2/2), respectively. The most significant toxicities of nab-PTX were grade 2/3 peripheral sensory neuropathy (24%) and grade 3/4 neutropenia (26%). Febrile neutropenia was not observed in any patient. The most significant toxicities of FEC were grade 3/4 neutropenia (24%) and grade 3 febrile neutropenia (9%). One patient died of sepsis secondary to pneumonia during FEC treatment. CONCLUSIONS: Neoadjuvant chemotherapy using nab-PTX with trastuzumab every 3 weeks followed by FEC was suitably tolerated and associated with a high pCR rate of 55% for patients with HER2-positive breast cancer.

A case of neuronal intranuclear inclusion disease with recurrent vomiting and without apparent DWI abnormality for the first seven years.

Neuronal intranuclear inclusion disease (NIID) is a rare, neurodegenerative disorder characterized by the presence of eosinophilic hyaline intranuclear inclusions, which are ubiquitin-positive and p62-positive, in neuronal and somatic cells; this can be observed on skin biopsy. Although patients with NIID present with a variety of symptoms that often make the diagnosis difficult, characteristic high-signal intensity of the corticomedullary junction on diffusion-weighted imaging (DWI) often provides a clue to the diagnosis of NIID. We present a case of NIID in a 57-year-old woman who only had recurrent vomiting for four years, which is uncommon as the presenting symptom; moreover, DWI showed no apparent abnormality until a slightly abnormal intensity lesion appeared at the right frontal corticomedullary junction seven years after the first episode of recurrent vomiting. Skin biopsies revealed multiple p62-positive nuclear inclusions, and genetic test showed GGC repeat expansion in NOTCH2NLC; this may form the genetic basis for NIID. Retrospectively, we found that abnormal cerebellar signals besides the vermis in the fluid attenuation inversion recovery (FLAIR) images were detected early-on in the disease. Periodic vomiting may be the only symptom of NIID in the early stages of the disease, and cerebellar abnormalities in FLAIR may serve as an important finding in the diagnosis of NIID, even in the absence of characteristic clinical symptoms or abnormal DWI signals at the cerebral corticomedullary junction.

Generation of novel genetically modified rats to reveal the molecular mechanisms of vitamin D actions.

Recent studies have suggested that vitamin D activities involve vitamin D receptor (VDR)-dependent and VDR-independent effects of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 25-hydroxyvitamin D3 (25(OH)D3) and ligand-independent effects of the VDR. Here, we describe a novel in vivo system using genetically modified rats deficient in the Cyp27b1 or Vdr genes. Type II rickets model rats with a mutant Vdr (R270L), which recognizes 1,25(OH)2D3 with an affinity equivalent to that for 25(OH)D3, were also generated. Although Cyp27b1-knockout (KO), Vdr-KO, and Vdr (R270L) rats each showed rickets symptoms, including abnormal bone formation, they were significantly different from each other. Administration of 25(OH)D3 reversed rickets symptoms in Cyp27b1-KO and Vdr (R270L) rats. Interestingly, 1,25(OH)2D3 was synthesized in Cyp27b1-KO rats, probably by Cyp27a1. In contrast, the effects of 25(OH)D3 on Vdr (R270L) rats strongly suggested a direct action of 25(OH)D3 via VDR-genomic pathways. These results convincingly suggest the usefulness of our in vivo system.

Nonconvulsive status epilepticus associated with Alzheimer's disease mimicking symptomatic focal epilepsy following the resection of a frontal parasagittal meningioma.

BACKGROUND: Epilepsies are frequent in patients with Alzheimer's disease (AD); however, epilepsies in AD can easily go unrecognized because they usually present as focal impaired awareness seizures or nonconvulsive status epilepticus (NCSE) and can overlap with other symptoms of AD. CASE DESCRIPTION: We performed an epilepsy surgery in a 69-year-old woman with progressive cognitive impairment and consciousness disorder, who was diagnosed with focal NCSE related to the resected meningioma in the right frontal parasagittal region. Intraoperative electrocorticography revealed localized periodic paroxysmal discharges with beta and gamma activities in the neighboring cortex where the meningioma existed. The histopathological diagnosis of AD was first made from the resected epileptogenic cortex. CONCLUSION: Even when there is a suspected epileptogenic lesion that could cause focal NCSE, AD should be ruled out in elderly patients with progressive cognitive decline.

Susceptibility to Various Coccidiostats in the Murine Coccidian Parasite Eimeria krijgsmanni.

INTRODUCTION: Murine Eimeria spp. have been used as effective experimental models of disease instead of large mammalian hosts such as cattle. We here examine drug susceptibility of the uncharacterized murine intestinal protozoan parasite, Eimeria krijgsmanni. MATERIALS AND METHODS: The effectiveness of different treatments against infection of E. krijgsmanni was examined for suppression of oocyst shedding: ST mixture ST mixture, pyrimethamine, Ektecin and toltrazuril. RESULTS: ST mixture and pyrimethamine did not suppress oocyst shedding effectively. Although therapeutic efficacy of Ektecin was demonstrated, the dose required was larger than that for cattle and chickens. Oocyst shedding was only completely suppressed completely by continuous administration of toltrazuril. Furthermore, it was confirmed through morphological examination that early developmental stage zoites appeared in host epithelial cells during and following treatment by toltrazuril, and toltrazuril could not eliminate residual zoites in epithelial cells. CONCLUSION: E. krijgsmanni may be relatively resistant to these anti-coccidian agents and might therefore have different characteristics that differ from other coccidia with regard to drug susceptibility.

Generation of 1,25-dihydroxyvitamin D3 in Cyp27b1 knockout mice by treatment with 25-hydroxyvitamin D3 rescued their rachitic phenotypes.

We have reported that 25-hydroxyvitamin D3 [25(OH)D3] binds to vitamin D receptor and exhibits several biological functions directly in vitro. To evaluate the direct effect of 25(OH)D3 in vivo, we used Cyp27b1 knockout (KO) mice, which had no detectable plasma 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] when fed a diet containing normal Ca and vitamin D. Daily treatment with 25(OH)D3 at 250 µg kg-1 day-1 rescued rachitic phenotypes in the Cyp27b1 KO mice. Bone mineral density, female sexual cycles, and plasma levels of Ca, P, and PTH were all normalized following 25(OH)D3 administration. An elevated Cyp24a1 mRNA expression was observed in the kidneys, and plasma concentrations of Cyp24a1-dependent metabolites of 25(OH)D3 were increased. To our surprise, 1,25(OH)2D3 was detected at a normal level in the plasma of Cyp27b1 KO mice. The F1 to F4 generations of Cyp27b1 KO mice fed 25(OH)D3 showed normal growth, normal plasma levels of Ca, P, and parathyroid hormone, and normal bone mineral density. The curative effect of 25(OH)D3 was considered to depend on the de novo synthesis of 1,25(OH)2D3 in the Cyp27b1 KO mice. This suggests that another enzyme than Cyp27b1 is present for the 1,25(OH)2D3 synthesis. Interestingly, the liver mitochondrial fraction prepared from Cyp27b1 KO mice converted 25(OH)D3 to 1,25(OH)2D3. The most probable candidate is Cyp27a1. Our findings suggest that 25(OH)D3 may be useful for the treatment and prevention of osteoporosis for patients with chronic kidney disease.

Utility of thermographic measurements of laterality of body surface temperature to prevent misdiagnosis of acute Wallenberg's syndrome.

INTRODUCTION: Acute Wallenberg's syndrome (WS) is sometimes misdiagnosed as a nonstroke disease including auditory vertigo, and careful neurological examination is required for a precise diagnosis. Lateral difference of body surface temperature (BST) had been reported as a symptom of WS, although further details of this symptom are currently lacking. Our aim was to investigate the laterality of BST of patients with acute WS using thermography and the usefulness of thermography to detect acute WS. METHODS: Nine consecutive patients with new-onset acute WS and nine patients with acute pontine infarction, intended for a comparison, were enrolled. Using thermography, the BST of patients was measured and initially evaluated visually. Detailed BSTs were measured using dedicated software. We examined the relationship between BST and other clinical factors, including first diagnosis, clinical symptoms, and MRI findings. RESULTS: Four patients with WS (44.44%) were misdiagnosed with nonstroke disease and did not receive a thermography assessment at their first visit; in contrast, all acute pontine infarction patients were diagnosed with brain infarction. Eight patients with WS (89%) showed a laterality of BST at multiple sites, and three of eight patients showed a whole-body laterality of BST; in contrast, only two pontine infarction patients showed laterality of BST at one or two sites. These lateral BST differences were easily observed visually using thermography within two minutes. The BST laterality gradually decreased over time in almost all patients with WS. The infarction size in the WS patients with whole-body laterality of BST was craniocaudally larger than in the other patients, and the size was smallest in the patient showing no BST laterality. CONCLUSIONS: In contrast to acute pontine infarction patients, almost all patients with acute WS showed lateral BST differences, which was easily detected with thermography. Thermography may thus be a useful tool to prevent misdiagnosis of acute WS.

Pharmacological characterization of nicotine-induced tremor: Responses to anti-tremor and anti-epileptic agents.

We previously showed that nicotine evoked kinetic tremor by activating the inferior olive, which is implicated in the pathogenesis of essential tremor, via α7 nicotinic acetylcholine receptors. Here, we evaluated the effects of various anti-tremor and anti-epileptic agents on nicotine-induced tremor in mice to clarify the pharmacological characteristics of nicotine tremor. Drugs effective for essential tremor, propranolol, diazepam and phenobarbital, all significantly inhibited kinetic tremor induced by an intraperitoneal (i.p.) injection of nicotine (1 mg/kg). In contrast, none of the medications for Parkinson's disease, l-DOPA, bromocriptine or trihexyphenidyl, affected the nicotine tremor. Among the anti-epileptic agents examined, valproate, carbamazepine and ethosuximide, significantly inhibited nicotine-induced tremor. In addition, a selective T-type Ca2+ channel blocker, TTA-A2, also suppressed the nicotine tremor. However, neither gabapentin, topiramate, zonisamide nor levetiracetam significantly affected nicotine-induced tremor. The present results show that nicotine-induced tremor resembles essential tremor not only on the neural basis, but also in terms of the pharmacological responses to anti-tremor agents, implying that nicotine-induced tremor can serve as a model for essential tremor. In addition, it is suggested that anti-epileptic agents, which have stimulant actions on the GABAergic system or blocking actions on voltage-gated Na+ channels and T-type Ca2+ channels, can alleviate essential tremor.

Time-Resolved Measurement of the ATP-Dependent Motion of the Group II Chaperonin by Diffracted Electron Tracking.

Previously, we demonstrated the ATP-dependent dynamics of a group II chaperonin at the single-molecule level by diffracted X-ray tracking (DXT). The disadvantage of DXT is that it requires a strong X-ray source and also perfect gold nano-crystals. To resolve this problem, we developed diffracted electron tracking (DET). Electron beams have scattering cross-sections that are approximately 1000 times larger than those of X-rays. Thus, DET enables us to perform super-accurate measurements of the time-resolved 3D motion of proteins labeled with commercially available gold nanorods using a scanning electron microscope. In this study, we compared DXT and DET using the group II chaperonin from Methanococcus maripaludis (MmCpn) as a model protein. In DET, the samples are prepared in an environmental cell (EC). To reduce the electron beam-induced protein damage, we immobilized MmCpn on the bottom of the EC to expose gold nanorods close to the carbon thin film. The sample setup worked well, and the motions of gold nanorods were clearly traced. Compared with the results of DXT, the mobility in DET was significantly higher, which is probably due to the difference in the method for immobilization. In DET, MmCpn was immobilized on a film of triacetyl cellulose. Whereas proteins are directly attached on the surface of solid support in DXT. Therefore, MmCpn could move relatively freely in DET. DET will be a state-of-the-art technology for analyzing protein dynamics.