150 research outputs found
Effects of ipsilateral cerebellum ablation on acquisition and retention of classically conditioned eyeblink responses in rats.
The ipsilateral cerebellum to the trained eye has been reported to be essential for acquisition and retention of the conditioned response (CR) in rabbit eyeblink conditioning. Although pharmacological studies have suggested its important roles in other species too, to what degree does eyeblink conditioning in rats depend on the ipsilateral cerebellum is not clear. In this work, we ablated the ipsilateral cerebellum in rats before or after conditioning to examine its roles in acquisition and retention of the CR. In the first experiment, rats received ablation of the ipsilateral cerebellum and recovered for more than 3 weeks. They then underwent eyeblink conditioning for 7 days with a tone and a periorbital electrical shock. Consistent with other previous reports, hemicerebellectomized rats showed significant impairment compared to sham-lesioned rats. However, the hemicerebellectomized rats acquired CRs to some degree, and the acquired CR showed adaptive timing. In the second experiment, rats received the hemicerebellectomy after acquiring CR by 7 days of conditioning in a delay paradigm. After more than 3 weeks of recovery, they were again conditioned in a delay paradigm. Rats with ipsilateral cerebellar lesions showed severe impairment in retention of the pre-acquired CR; however, they reacquired CR to some degree during the subsequent reconditioning sessions. These results suggest that the ipsilateral cerebellum plays an important role in rat eyeblink conditioning as well but that other brain regions can partially compensate for its removal
Introduction of New Features in Writer Verification Based on Finger-writing of a Simple Symbol
In this study, a method of verifying an individual from their style of drawing simple symbols that everyone is familiar with and never forgets was studied. Individuals were asked to draw symbols using their fingertips on a digital device screen. Various features, such as the finger pressure, the touch area, and the touch direction, which were directly detected by a tablet device, were measured. In addition, the finger volume, force, and amount of work that were derived from the directly detected features were calculated. Subsequently, the verification performance of these features was evaluated
Prognosis and prognostic factors in patients with intermediate-risk papillary thyroid carcinoma defined by the Japanese clinical practice guidelines for thyroid tumours
Ruptured anterior paraclinoid aneurysms
The purpose of this study was to evaluate cases of subarachnoid hemorrhage (SAH) from ruptured anterior (dorsal) paraclinoid aneurysms. Anterior paraclinoid aneurysms are defined as aneurysms arising from the anterolateral wall of the proximal internal carotid artery without any relationship to an arterial branch. Between 1991 and 2008, a total of 159 patients with 169 paraclinoid aneurysms were treated at the Shinshu University Hospital and its affiliated hospitals. A retrospective analysis was carried out using charts, operation records, operation videos, and neuroimagings. Twenty six patients had anterior paraclinoid aneurysm. Six patients presented with SAH. Three aneurysms were saccular and the others were blister-like aneurysms based on operative findings. Neck laceration or premature rupture frequently happened during the clipping surgery even though the aneurysm was saccular type. The treatment of a ruptured anterior paraclinoid aneurysm is quite difficult. Trapping and bypass would be recommended for such fragile aneurysms.ArticleNEUROSURGICAL REVIEW. 34(1):49-54 (2011)journal articl
Urgent open embolectomy for cardioembolic cervical internal carotid artery occlusion
Acute ischemic stroke attributable to cervical internal carotid artery (ICA) occlusion is frequently associated with severe disability or death and is usually caused by atherosclerosis. By contrast, the cardioembolic cervical ICA occlusion is rare, and feasibility of urgent recanalization remains unclear. We present the first study in the literature that focuses on urgent open embolectomy for the treatment of cardioembolic cervical ICA occlusion. A retrospective review of the charts for patients undergoing open embolectomy was performed. Between April 2006 and September 2007, 640 consecutive patients with acute ischemic stroke were treated. Of them, three patients (0.47%) with the acute complete cardioembolic cervical ICA occlusion underwent urgent open embolectomy. All patients presented with profound neurological deficits and atrial fibrillation. The urgent open embolectomy achieved complete recanalization in all patients without any complications. All emboli in three patients were very large and fibrinous in histological findings. Two of three patients showed rapid improvement in neurological functions after surgical treatments. The cardioembolic occlusion of the cervical ICA is rare, but its possibility should be considered in patients with acute ischemic stroke suffering profound neurological deficits and atrial fibrillation. Urgent open embolectomy may be a treatment option to obtain successful recanalization for cardioembolic cervical ICA occlusion and is recommended because it is technically easier and similar to carotid endarterectomy.ArticleNEUROSURGICAL REVIEW. 33(3):341-348 (2010)journal articl
Safe and minimally invasive laminoplastic laminotomy using an ultrasonic bone curette for spinal surgery: technical note
Background: Ultrasonic surgical aspirators have been used mainly for removing brain tumors. Because of their longitudinal and torsional tip, they are used for cutting the bone structures in spinal surgery installing a scalpel-type tip. The purpose of this report is to describe the effectiveness and surgical pitfalls of an ultrasonic bone curette in laminoplastic laminotomy and hemilaminotomy. Methods: We present 12 patients who underwent laminoplastic laminotomy and hemilaminotomy. We used a SONOPET UST-2001 ultrasonic bone curette with HB-05S handpieces (M and M Co, Ltd, Tokyo, Japan). After a tumor was removed, titanium plates were used for the laminoplastic laminotomy and hemilaminotomy. The technical advantage of an ultrasonic bone curette and procedure-related complication were examined. Results: There were no major procedure-related complications such as cord injury. Wound infection and subcutaneous fluid collection caused by cerebrospinal fluid leakage did not occur for reconstruction of posterior bony structure. In 1 patient with calcified dura mater associated with tumor, dural tear occurred. The width of the tip was narrow enough for resected laminae to be fused postoperatively, and spinal instability did not occur in all cases. Conclusion: The scalpel-type ultrasonic bone curette is useful for cutting bone and effective for reconstruction of the laminae. Laminotomy with an ultrasonic bone curette is safe and minimally invasive. To prevent dural tear, we recommend drilling laminae to make the bone thin as the first step, followed by cutting the remaining laminae using a bone curette especially in cases with calcified or tense dura mater.ArticleSURGICAL NEUROLOGY. 72(5):470-475 (2009)journal articl
Improving Eye Motion Sequence Recognition Using Electrooculography Based on Context-Dependent HMM
Eye motion-based human-machine interfaces are used to provide a means of communication for those who can move nothing but their eyes because of injury or disease. To detect eye motions, electrooculography (EOG) is used. For efficient communication, the input speed is critical. However, it is difficult for conventional EOG recognition methods to accurately recognize fast, sequentially input eye motions because adjacent eye motions influence each other. In this paper, we propose a context-dependent hidden Markov model- (HMM-) based EOG modeling approach that uses separate models for identical eye motions with different contexts. Because the influence of adjacent eye motions is explicitly modeled, higher recognition accuracy is achieved. Additionally, we propose a method of user adaptation based on a user-independent EOG model to investigate the trade-off between recognition accuracy and the amount of user-dependent data required for HMM training. Experimental results show that when the proposed context-dependent HMMs are used, the character error rate (CER) is significantly reduced compared with the conventional baseline under user-dependent conditions, from 36.0 to 1.3%. Although the CER increases again to 17.3% when the context-dependent but user-independent HMMs are used, it can be reduced to 7.3% by applying the proposed user adaptation method
Efficacy and safety of addition of minor bloodletting (petit phlebotomy) in hepatitis C virus-infected patients receiving regular glycyrrhizin injections
The original publication is available at www.springerlink.comBackground: Hepatoprotective therapies that include regular glycyrrhizin injection (GI) are beneficial for chronic hepatitis C patients, but are sometimes unable to normalize serum alanine aminotransferase (ALT) levels. Here, we evaluated whether the addition of minor bloodletting, named petit phlebotomy (PP), prior to each GI could further reduce serum ALT concentrations in such patients. Methods: Seventy-six HCV-infected patients receiving regular GI with persistently abnormal serum ALT levels were randomly divided into GI+PP or GI groups and monitored for 12 months. PP was performed before every GI to a total 60 ml of blood a week. The primary PP endpoint was serum ferritin levels of less than 20 ng/ml. PP was suspended upon reaching the endpoint, but was resumed as needed. The efficacy of the addition of PP was evaluated by measuring changes in serum ALT levels. Results: Two patients in each group dropped out because of apparition of hepatocellular carcinoma. The remainder completed the 12-month treatment with no serious adverse events. Serum ALT and ferritin levels were significantly decreased in the GI+PP group (from 67 + 34 to 44 + 14 U/l and from 163 + 127 to 25 + 21 ng/ml, respectively, both P<0.001), but these changes were not seen in the GI group. Although twenty patients in the GI+PP group had compensated cirrhosis, no significant reductions in serum albumin concentrations were observed. Conclusions: The addition of PP is effective and safe for improving serum aminotransferase levels in HCV-infected patients receiving regular GI, even in those with compensated cirrhosis.ArticleJournal of Gastroenterology 44(6): 577-582(2009)journal articl
Early treatment with a sodium-glucose co-transporter 2 inhibitor in high-risk patients with acute heart failure:Rationale for and design of the EMPA-AHF trial
Aims: The aim of the EMPA-AHF trial is to clarify whether early initiation of a sodium-glucose co-transporter 2 inhibitor before clinical stabilization is safe and beneficial for patients with acute heart failure (AHF) who are at a high risk of adverse events. Methods: The EMPA-AHF trial is a randomized, double-blind, placebo-controlled, multicentre trial examining the efficacy and safety of early initiation of empagliflozin (10 mg once daily). In total, 500 patients admitted for AHF will be randomized 1:1 to either empagliflozin 10 mg daily or placebo at 47 sites in Japan. Study entry requires hospitalization for AHF with dyspnoea, signs of volume overload, elevated natriuretic peptide, and at least one of the following criteria: estimated glomerular filtration rate <60 mL/min/1.73 m2; already taking ≥40 mg of furosemide daily before hospitalization; and urine output of <300 mL within 2 hours after an adequate dose of intravenous furosemide. Patients will be randomized within 12 hours of hospital presentation, with treatment continued up to 90 days. The primary outcome is the clinical benefit of empagliflozin on the win ratio for a hierarchical composite endpoint consisting of death within 90 days, heart failure rehospitalization within 90 days, worsening heart failure during hospitalization, and urine output within 48 hours after treatment initiation. Conclusion: The EMPA-AHF trial is the first to evaluate the efficacy and safety of early initiation of empagliflozin in patients with AHF considered to be at high risk under conventional treatment.</p
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