An Alternative Approach for Radiofrequency Catheter Ablation for Intra-atrial Reentrant Tachycardia Associated with Open-Heart Surgery

We present case reports of 2 patients with scar-related intra-atrial reentrant tachycardia (IART) associated with previous open-heart surgeries, in which standard ablation strategies failed to eliminate atrial tachycardia (AT). The strategies targeted a narrow conducting channel between the right atrial scars or between the scar and inferior vena cava. In these patients, an alternative approach to transect another narrow conducting pathway between the scar and crista terminalis (CT), which was revealed by a noncontact mapping system, successfully terminated and eliminated the IART. Both the cases were free of recurrent AT at the 24-and 25-month follow up visits, respectively. Transection of the corridor between the CT and the incision scar appears to be an effective technique for eliminating scar-related IART and can be considered as a second-line procedure for radiofrequency catheter ablation to eliminate IART

Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ): Part 2. Endorsement of the alternative item

AbstractBackgroundA new self-administered questionnaire as an outcome measure for patients with cervical myelopathy was drawn up in Part 1 (Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, JOACMEQ). Because a question with regard to driving a car (C-41) was not suitable for this patient group, the authors composed an alternative question related to neck motion (C-41-2). The purposes of the present study were to perform a secondary survey on patients with cervical myelopathy and to statistically analyze the responses to validate the JOACMEQ, and also to determine if it was possible to convert item C-41 to the alternative question.MethodsA member of the Subcommittee on Low Back Pain and Cervical Myelopathy Evaluation from each hospital administered the questionnaire to more than 50 patients with cervical myelopathy in each hospital. The questionnaire consisted of 25 questions, 24 of which were extracted in the primary survey. The authors statistically examined whether it was possible to convert question C-41 to C-41-2.ResultsThree hundred and sixty-eight patients with cervical myelopathy were enrolled in the present study. No questions elicited no answer or “I am not sure” in more than 5% of patients except question C-41. There were no questions that the patients answered with difficulty. There was no tendency that was concentrated on one option as an answer to questions. There was a high correlation between questions C-41 and C-41-2. Spearman’s correlation coefficient and κ value showed that there was high coincidence between the two questions C-41 and C-41-2. It is possible to convert the question C-41 to the alternative question C41-2.ConclusionThe questionnaire has sufficient reliability for clinical use. It is possible that the JOACMEQ will prevail and become a global standard to evaluate outcomes in patients with cervical myelopathy

Involvement of the accumbal osteopontin-interacting transmembrane protein 168 in methamphetamine-induced place preference and hyperlocomotion in mice

Chronic exposure to methamphetamine causes adaptive changes in brain, which underlie dependence symptoms. We have found that the transmembrane protein 168 (TMEM168) is overexpressed in the nucleus accumbens of mice upon repeated methamphetamine administration. Here, we firstly demonstrate the inhibitory effect of TMEM168 on methamphetamine-induced behavioral changes in mice, and attempt to elucidate the mechanism of this inhibition. We overexpressed TMEM168 in the nucleus accumbens of mice by using an adeno-associated virus vector (NAc-TMEM mice). Methamphetamine-induced hyperlocomotion and conditioned place preference were attenuated in NAc-TMEM mice. Additionally, methamphetamine-induced extracellular dopamine elevation was suppressed in the nucleus accumbens of NAc-TMEM mice. Next, we identified extracellular matrix protein osteopontin as an interacting partner of TMEM168, by conducting immunoprecipitation in cultured COS-7 cells. TMEM168 overexpression in COS-7 cells induced the enhancement of extracellular and intracellular osteopontin. Similarly, osteopontin enhancement was also observed in the nucleus accumbens of NAc-TMEM mice, in in vivo studies. Furthermore, the infusion of osteopontin proteins into the nucleus accumbens of mice was found to inhibit methamphetamine-induced hyperlocomotion and conditioned place preference. Our studies suggest that the TMEM168-regulated osteopontin system is a novel target pathway for the therapy of methamphetamine dependence, via regulating the dopaminergic function in the nucleus accumbens

Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. Part 3. Validity study and establishment of the measurement scale: Subcommittee on Low Back Pain and Cervical Myelopathy Evaluation of the Clinical Outcome Committee of the Japanese Orthopaedic Association, Japan

AbstractBackgroundThe Japanese Orthopaedic Association decided to revise the JOA score for low back pain and to develop a new outcome measure. In February 2002, the first survey was performed with a preliminary questionnaire consisting of 60 evaluation items. Based on findings of that survey, 25 items were selected for a draft of the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The second survey was performed to confirm the reliability of the draft questionnaire. This article further evaluates the validity of this questionnaire and establishes a measurement scale.MethodsThe subjects of this study consisted of 355 patients with low back disorders of any type (201 men, 154 women; mean age 50.7 years). Each patient was asked to fill in a self-administered questionnaire. Superficial validity was checked in terms of the completion rate for filling out the entire questionnaire. Factor analysis was then performed to evaluate the validity of the questionnaire and establish a measurement scale.ResultsAs a result of the factor analysis, 25 items were categorized into five factors. The factors were named based on the commonality of the items: social function, mental health, lumbar function, walking ability, and low back pain. To establish a measurement scale for each factor, we determined the coefficient for each item so the difference between the maximum factor scores and minimum factor scores was approximately 100. We adjusted the formula so the maximum for each factor score was 100 and the minimum was 0.ConclusionsWe confirmed the validity of the JOA Back Pain Evaluation Questionnaire and est ablished a measurement scale

Induction of neuronal axon outgrowth by Shati/Nat8l via energy metabolism in mice cultured neurons

A novel N-acetyltransferase, Shati/Nat8l, was identified in the nucleus accumbens of mice repeatedly treated with methamphetamine (METH). Shati/Nat8l has been reported to inhibit the pharmacological action induced by METH. Shati/Nat8l produces N-acetylaspartate from aspartate and acetyl-CoA. Previously, we reported that overexpression of Shati/Nat8l in nucleus accumbens attenuates the response to METH by N-acetylaspartylglutamate (which is derived from N-acetylaspartate)-mGluR3 signaling in the mice brain. In the present study, to clarify the type of cells that produce Shati/Nat8l, we carried out in-situ hybridization for the detection of Shati/Nat8l mRNA along with immunohistochemical studies using serial sections of mice brain. Shati/Nat8l mRNA was detected in neuronal cells, but not in astrocytes or microglia cells. Next, we investigated the function of Shati/Nat8l in the neuronal cells in mice brain; then, we used an adeno-associated virus vector containing Shati/Nat8l for transfection and overexpression of Shati/Nat8l protein into the primary cultured neurons to investigate the contribution toward the neuronal activity of Shati/Nat8l. Overexpression of Shati/Nat8l in the mice primary cultured neurons induced axonal growth, but not dendrite elongation at day 1.5 (DIV). This finding indicated that Shati/Nat8l contributes toward neuronal development. LY341495, a selective group II mGluRs antagonist, did not abolish this axonal growth, and N-acetylaspartylglutamate itself did not abolish axon outgrowth in the same cultured system. The cultured neurons overexpressing Shati/Nat8l contained high ATP, suggesting that axon outgrowth is dependent on energy metabolism. This study shows that Shati/Nat8l in the neuron may induce axon outgrowth by ATP synthesis and not through mGluR3 signaling

Nanometer-size hard magnetic ferrite exhibiting high optical-transparency and nonlinear optical-magnetoelectric effect

Development of nanometer-sized magnetic particles exhibiting a large coercive field (Hc) is in high demand for densification of magnetic recording. Herein, we report a single-nanosize (i.e., less than ten nanometers across) hard magnetic ferrite. This magnetic ferrite is composed of ε-Fe2O3, with a sufficiently high Hc value for magnetic recording systems and a remarkably high magnetic anisotropy constant of 7.7 × 106 erg cm−3. For example, 8.2-nm nanoparticles have an Hc value of 5.2 kOe at room temperature. A colloidal solution of these nanoparticles possesses a light orange color due to a wide band gap of 2.9 eV (430 nm), indicating a possibility of transparent magnetic pigments. Additionally, we have observed magnetization-induced second harmonic generation (MSHG). The nonlinear optical-magnetoelectric effect of the present polar magnetic nanocrystal was quite strong. These findings have been demonstrated in a simple iron oxide, which is highly significant from the viewpoints of economic cost and mass production.UTokyo Research掲載「世界最小ハードフェライト磁石の開発に成功」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/the-worlds-smallest-hard-ferrite-magnet.htmlUTokyo Research "The world\u27s smallest hard ferrite magnet" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/the-worlds-smallest-hard-ferrite-magnet.htm

Vasodilative effects of prostaglandin E1 derivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina

<p>Abstract</p> <p>Background</p> <p>Reduction of blood flow is important in the induction of neurogenic intermittent claudication (NIC) in lumbar spinal canal stenosis. PGE₁improves the mean walking distance in patients with NIC type cauda equina compression. PGE₁derivate might be effective in dilating blood vessels and improving blood flow in nerve roots with chronically compressed cauda equina. The aim of this study was to assess whether PGE₁derivate has vasodilatory effects on both arteries and veins in a canine model of chronic cauda equina compression.</p> <p>Methods</p> <p>Fourteen dogs were used in this study. A plastic balloon inflated to 10 mmHg was placed under the lamina of the 7th lumbar vertebra for 1 week. OP-1206-cyclodextrin clathrate (OP-1206-CD: prostaglandin E₁derivate) was administered orally. The blood vessels of the second or third sacral nerve root were identified using a specially designed surgical microscope equipped with a video camera. The diameter of the blood vessels was measured on video-recordings every 15 minutes until 90 minutes after the administration of the PGE₁derivate.</p> <p>Results</p> <p>We observed seven arteries and seven veins. The diameter and blood flow of the arteries was significantly increased compared with the veins at both 60 and 75 minutes after administration of the PGE₁derivate (p < 0.05). Blood flow velocity did not change over 90 minutes in either the arteries or veins.</p> <p>Discussion</p> <p>The PGE₁derivate improved blood flow in the arteries but did not induce blood stasis in the veins. Our results suggest that the PGE₁derivate might be a potential therapeutic agent, as it improved blood flow in the nerve roots in a canine model of chronic cauda equina compression.</p

Striatal N-Acetylaspartate Synthetase Shati/Nat8l Regulates Depression-Like Behaviors via mGluR3-Mediated Serotonergic Suppression in Mice

Background: Several clinical studies have suggested that N-acetylaspartate and N-acetylaspartylglutamate levels in the human brain are associated with various psychiatric disorders, including major depressive disorder. We have previously identified Shati/Nat8l, an N-acetyltransferase, in the brain using an animal model of psychosis. Shati/Nat8l synthesizes N-acetylaspartate from L-aspartate and acetyl-coenzyme A. Further, N-acetylaspartate is converted into N-acetylaspartylglutamate, a neurotransmitter for metabotropic glutamate receptor 3.Methods: Because Shati/Nat8l mRNA levels were increased in the dorsal striatum of mice following the exposure to forced swimming stress, Shati/Nat8l was overexpressed in mice by the microinjection of adeno-associated virus vectors containing Shati/Nat8l gene into the dorsal striatum (dS-Shati/Nat8l mice). The dS-Shati/Nat8l mice were further assessed using behavioral and neurochemical tests.Results: The dS-Shati/Nat8l mice exhibited behavioral despair in the forced swimming and tail suspension tests and social withdrawal in the 3-chamber social interaction test. These depression-like behaviors were attenuated by the administration of a metabotropic glutamate receptor 2/3 antagonist and a selective serotonin reuptake inhibitor. Furthermore, the metabolism of N-acetylaspartate to N-acetylaspartylglutamate was decreased in the dorsal striatum of the dS-Shati/Nat8l mice. This finding corresponded with the increased expression of glutamate carboxypeptidase II, an enzyme that metabolizes Nacetylaspartylglutamate present in the extracellular space. Extracellular serotonin levels were lower in the dorsal striatum of the dS-Shati/Nat8l and normal mice that were repeatedly administered a selective glutamate carboxypeptidase II inhibitor.Conclusions: Our findings indicate that the striatal expression of N-acetylaspartate synthetase Shati/Nat8l plays a role in major depressive disorder via the metabotropic glutamate receptor 3-mediated functional control of the serotonergic neuronal system