An experimental study on the relation of T2-signal high intensity in MRI to histopathological changes in the kainic acid model of temporal lobe epilepsy in rats.

側頭葉てんかんでは，てんかん焦点に一致してMRI T2高信号領域が見られ，FLAIR法でこれがより明瞭になるが，このMRI所見と病理組織学的変化との関係は必ずしもはっきりしていない。そこで，Sprague－Dawleyラットにカイニン酸（KA）でけいれん発作重積状態を起こし，経時的にMRIを記録するとともに，ニッスル染色，GFAP免疫染色での病理組織学的変化を調べて両者の関係について検討した。KA群では，MRIで1～8週間後のいずれにおいてもpiriform cortexからentorhinal cortexにかけて不整形のT2高信号領域がみられたが，stage3のけいれん発作しか出現しなかったラットではstage4，5が出現したラットに比べて程度が弱かった。組織学的には，CA1，subiculum，piriform cortex，entorhinal cortexで神経細胞の消失，濃染細胞の増加と萎縮，GFAP免疫反応の増強が見られたが，piriform cortex，entorhinal cortexでの神経細胞消失の程度はT2信 号の程度と相関せず，GFAP免疫反応が増強した領域に一致して高信号がみられた。しかし，海馬のGFAP免疫反応増強はMRI所見に反映されず，これはMRIの解像度の限界にもよると考えられた。The relation of T2-signal high intensity areas observed in temporal lobe epilepsy to histopathological changes in limbic structures was examined in the rat kainic acid (KA) model of epilepsy. Male 8-week-old Sprague-Dawley rats were injected with 10mg/kg(i.p.) of KA or saline (control). Repetitive generalized convulsions (stage 3, or stage 4,5 seizures of amygdala kindled seizures) lasted for 3 to 4 hrs. were induced by KA injection in all rats. MRI was recorded on the day before the KA injection and 1, 2, 4, 8 weeks after the injection by fluid-attenuated inversion recovery method under deep pentobarbital anesthesia. Following the last MRI recording, rats were perfused with 4% paraformaldehyde (PFA) from left cardiac ventricle, post-fixed overnight in 4% PFA and brains were embedded in parafin. Coronal brain sections (6μm) were stained with cresyl violet, or mouse anti-GFAP antibody followed by biotinylated goat anti-mouse IgG and avidin-biotin-peroxidase (vectastain ABC kit). Irregularshaped moderate to severe high T2-signal areas were observed in bilateral piriform and entorhinal cortex in MRI. These high T2-signal areas were ovserved from 1 week after the KA injection to 8 weeks after the injection, and were more prominent in rats elicited stage 4 or 5 seizures than in rats elicited stage 3 seizures. Loss of pyramidal neurons and increased GFAP immunoreactivity were observed in piriform cortex, entorhinal cortex, CA1, subiculum, and hilus of dentate gyrus. The increase of GFAP immunoreactivity, but not the intensity of neuronal loss, in piriform and entorhinal cortex was almost correponded to the size and intensity of T2-signal. However, the increase of GFAP immunoreactivity in hippocampus was not detected as the increase of T2-signal in MRI. These findings indicate that astroglial reactions in piriform and entorhinal cortex are more sensitive to T2-weighted MRI than those in hippocampus

Jugular Vein Technique for Serial Blood Sampling in the Hamster

The puncture is performed via the external jugular vein in hamster (100g) under appropriate anesthesia and will give 1 ml within 30 seconds with certainty and security. Blood volumes up to 1 ml have been obtained once a week for a period of 20 weeks

要支援高齢者の会話に基づく自己効力感を高める通所介護プログラムの検討

［目的］本研究は，通所介護を利用する要支援高齢者の会話から言語表現の特徴を探り，その特徴に基づいた自己効力感を高める通所介護プログラムを検討する．［方法］通所介護施設を利用する要支援高齢者38人を対象とし，その会話を分析した．会話の特徴を活かし，通所介護プログラムを検討した．［結果］対象者の会話の出現頻度が多かったものは，｢言う｣であった．次いで，「行く」「来る」であった．対象者の会話の特徴に基づいた通所介護プログラム実施後に得点が変化した自己効力感尺度の項目は，行動の積極性，能力への自信などであった．［結論］要支援高齢者の言語表現の特徴を活かしたプログラム実施後には，行動の積極性，能力への自信，社会的活動への意欲などの自己効力感得点が上昇した．要支援高齢者の通所介護プログラム作成にあたり，要支援高齢者の会話のなかにヒントがあることが明らかとなった．利用者の言語表現の特徴を活かした個別のプログラム作成が，自己効力感を高め，介護予防につながるのではないかと考えられる

Critical Point Mutations for Hepatitis C Virus NS3 Proteinase

AbstractThe hepatitis C virus NS3 proteinase plays an essential role in processing of HCV nonstructural precursor polyprotein. To detect its processing activity, we developed a simpletrans-cleavage assay. Two recombinant plasmids expressing the NS3 proteinase region and a chimeric substrate polyprotein containing the NS5A/5B cleavage site between maltose binding protein and protein A were co-introduced intoEscherichia colicells. The proteinase processed the substrate at the single site during their polyprotein expression. Deletion analysis indicated that the functionally minimal domain of the NS3 proteinase was composed of 146 amino acids, 1059 to 1204. We isolated several cDNA clones encoding the functional domain of the NS3 proteinase from the sera of patients chronically infected with HCV and determined their proteinase activity by thistrans-cleavage assay. Both active and inactive clones existed in the same patients. Comparative sequence analyses of these clones suggested that certain point mutations seemed to be related to the loss of proteolytic activity. This was confirmed by back mutation experiments. Among the critical mutations, Pro-1168 to Thr and Arg-1135 to Gly were intriguing. These amino acids, which are situated near the oxyanion hole, seem to be essential for maintaining the conformation of the active center of the NS3 proteinase

Phenotypes of pain behavior in phospholipase C-related but catalytically inactive protein type 1 knockout mice

Phospholipase C-related inactive protein (PRIP) plays important roles in trafficking to the plasma membrane of GABAA receptor, which is involved in the dominant inhibitory neurotransmission in the spinal cord and plays an important role in nociceptive transmission. However, the role of PRIP in pain sensation remains unknown. In this study, we investigated the phenotypes of pain behaviors in PRIP type 1 knockout (PRIP-1 -/- ) mice. The mutant mice showed hyperalgesic responses in the second phase of the formalin test and the von Frey test as compared with those in wild-type mice. In situ hybridization studies of GABAA receptors revealed significantly decreased expression of γ2 subunit mRNA in the dorsal and ventral horns of the spinal cord in PRIP-1 -/- mice, but no difference in α1 subunit mRNA expression. β2 subunit mRNA expression was significantly higher in PRIP-1 -/- mice than in wild-type mice in all areas of the spinal cord. On the other hand, the slow decay time constant for the spontaneous inhibitory current was significantly increased by treatment with diazepam in wild-type mice, but not in PRIP-1 -/- mice. These results suggest that PRIP-1 -/- mice exhibit the changes of the function and subunits expression of GABAA receptor in the spinal cord, which may be responsible for abnormal pain sensation in these mice

Multimodality imaging of biatrial myxomas in an asymptomatic patient

AbstractMyxomas are located in the left atrium in 75–80% of cases and almost always present with signs and symptoms of a thromboembolic event. Biatrial myxomas are rare, and their incidence is generally less than 2.5% of all myxomas. We herein present a case of biatrial myxomas as an incidental finding by echocardiography where the patient underwent surgery. Echocardiography continues to be the initial imaging modality for intracardiac masses. Cardiac magnetic resonance provides superior tissue characterization, particularly important in differentiating a myxoma from a thrombus. Appropriate use of these non-invasive imaging modalities may lead to a correct diagnosis and good outcome.<Learning objective: In this report we present a rare case of cardiac biatrial myxomas. Multimodality imaging, especially delayed enhancement cardiac magnetic resonance imaging, provided specific findings for the diagnosis.