The role of astrocytes during repair of cerebral infarction in mdx mice

様々な大きさのジストロフィンアイソフォーム(427kDa, 260kDa, 140kDa, 116kDa, 71-75kDa)が広く体内に存在していることはよく知られている.中枢神経系においては71-75kDaのDp71が著明に多く,毛細血管の内皮の基底膜に接しているアストロサイトの細胞質に局在することが報告されている.しかしながらDp71の機能についてはよくわかっていないことが多い.そこで今回,脳組織におけるDp71の役割を調べるために,コントロールマウス(wild-typeマウス)およびデュシャンヌ型筋ジストロフィーモデル動物であるmdxマウスを用いて実験的脳梗塞を作成し,その治癒過程を形態学的に観察した.また,GFAPおよびDp71に関して生化学的に分析をおこなった.HE染色およびGFAP免疫組織学的染色の結果から,形態学的にはmdxマウスとコントロールマウスの脳に違いは認められなかった.しかしながら,mdxマウスの脳において,Dp71の発現量がコントロールマウスよりも少ないことがわかった.またmdxマウスにおいて,脳梗塞の修復過程におけるアストロサイトの反応がコントロールマウスよりも弱いことがわかった.これらの結果から,mdxマウスの脳において,アストロサイトの機能,アストロサイトの血管新生に関わる機能の障害されていることが示唆された.It is now well known that dystrophin isoforms (427kDa, 260kDa, 140kDa, 116kDa, 71-75kDa) are widely distributed throughout our body. In the central nervous system a considerable amount of Dp71 (71-75kDa) is found in the perivascular cytoplasm of the astrocytes. However, the function of this dystrophin is still unknown. To investigate the role of Dp71 in the brain tissue, cerebral infarction was induced in the control (wide-type) mouse and mdx mouse which is known as an animal model of human muscle dystrophy (Duchenne type), and morphological changes of the infarcted area were observed during repair of the infarction. In addition, biochemical analysis of GFAP and Dp71 was carried out in the brain of the control and mdx mouse. In our present study, there were no differences in brain morphology between mdx and control mouse as revealed in H-E stain and GFAP immunohistochemistry. However, the Dp71 were smaller in quantity in the brain of the mdx mouse than that of the control mouse. The reaction of astrocytes during repair of serebral infarction was distinctly delayed in the mdx mouse compared with that of the control mouse. These findings suggest that the astrocytes in the brain of the mdx mouse are functionally impaired including perivascular cytoplasmic processes with relation to neo-vascularization

Expression of myogenin, MyoD and MHC isoforms in regenerating skeletal muscle.

骨格筋再生過程におけるミオシン重鎖(MHC)アイソフォーム発現とmyogenin，MyoDタンパクの発現様式との関連性を検討するために，塩酸ブピバカインを用いてマウスヒラメ筋損傷モデルを作成し，損傷筋の再生過程を組織形態学的に確認すると同時に，再生各段階におけるMHCアイソフォームと，myogeninおよびMyoDタンパク発現を経時的に検索した．本研究における筋損傷は塩酸ブピバカインをマウス(C57BL/10SnSlc)のヒラメ筋に注入することで作成した．組織学的には，塩酸ブピバカイン投与後3日目で筋線維はほとんど消失し，処置後6日目で中心核を有する再生筋線維がかなり出現し，処置後28日目では対照群のものと同程度まで回復した．生化学的分析では，対照群ヒラメ筋はMHCⅠ(34．3±1．7%)とMHCⅡa(65．7±1．7%)で構成されていた．実験群ヒラメ筋ではMHCⅠは処置後14日目まで減少し，その後増加傾向を示し，処置後90日目では36．3±2．9%となった．また，正常ヒラメ筋では検出されない速筋型MHC(MHC Ⅱd，MHC Ⅱb)が処置後3日目から28日目まで検出された．Western blotを用いた分析では，myogeninタンパク正常ヒラメ筋（遅筋）で検出された一方，前脛骨筋（速筋）においては検出できなかった．実験群ヒラメ筋では，myogeninは対照群と比較して処置後３日目より増加し（3．1±0．5），処置後６日目でピークに達した（5．8±0．8）．それからmyogeninタンパクは徐々に減少していったが，処置後90日目においてもなお対照群ヒラメ筋の1．8倍の発現を維持し続けた．一方，MyoDタンパクは正常前脛骨筋において正常ヒラメ筋の3．3倍の発現が認められた．MyoDは処置後３日目で対照群ヒラメ筋と比較して5．4倍になりピークに達した．その後は徐々に減少し始めた．しかし処置後90日目においても2．2倍の発現があった．これらのことから筋の再生過程においては速筋タイプの筋細胞が出現するmyogeninとMyoDは衛星細胞の分化と筋の再生に密接に関係していることが示唆された．To investigate the precise mechanism of skeletal muscle cell regeneration, the changing pattern ofmyosin heavy chain(MHC)isoforms during the regenerating process was observed with relation to theactivation of myogenin and MyoD. In addition, histopathological observation of the damaged muscles wasperformed throughout the experiment.In this study, muscle damage was induced by intramuscular injection of bupivacaine hydrochloride in thesoleus muscle of mice (C57BL/10SnSc). In the light microscopic observation, muscle cells had almost disappeared at 3 days after bupivacainetreatment with severe inflammatory cell infiltration. At 6 days after treatment, a considerable number ofregenerating muscle cells containing centrally located nuclei appeared in the damaged soleus muscle. At28 days, these regenerating muscle cells showed almost the same appearance as the control muscle cellscontaining subsarcolemmal nuclei, although a small number of muscle cells with central nuclei were stillrecognized.In the biochemical analysis, control soleus muscles contained only MHC I (34.3±1.7 %)and MHC IIa(65.7±1.7 %). In the damaged muscles, MHC I was decreased toward 14 days after treatment, and thengradually increased. At 90 days, the contents of MHC I was finally recovered to 36.3±2.9 %.0 In addition,MHC IId and MHC IIb appeared in the damaged muscle from 3 to 28 days after treatment. However, theyhad disappeared at 90 days.Using western blot analysis, myogenin protein was recognized in the control soleus muscles (slow typemuscle), while the myogenin could not be found in the first type muscle of the anterior tibial muscle. Themyogenin contents increased to about three fold (3.1±0.5)at 3 days after treatment compared withthose of control muscles and reached the maximum level (5.8±0.8)at 6 days after treatment. Then, myogenin contents gradually decreased,although they still remained high (1.8 times)at the end of experiment (90 days after treatment). Incontrast to the myogenin protein, a high level (3.3 times)of MyoD protein was detected in the anteriortibial muscle compared with that of control soleus muscles. In the damaged soleus muscles, MyoDcontents reached a maximum level (5.4 times)at 3 days after treatment compared with that of controlsoleus muscles, and then gradually decreased toward the end of experiment. However, MyoD protein stillremained 2.2 times compared with that of control soleus muscles. These findings described above indicate that, 1)a property of fast type muscle cells appeared in theregenerating muscle cells during the regenerating process, and 2)myogenin and MyoD are closelyrelated to the differentiation of the satellite cells and regeneration of the skeletal muscle cells

Function of skeletal muscle sarcoplasmic reticulum and expression of sarcoplasmic reticulum Ca2+-ATPase in right congestive heart failure rats

右心不全に伴って,速筋および遅筋の筋小胞体Ca2+取り込み能が減少するという仮説を検証した.右心不全は,モノクロタリン(30 ㎎/㎏)を投与することにより引き起こし,投与後4週で,長指伸筋およびヒラメ筋を両後肢から採取した.筋の疲労耐性は,連続的な強縮刺激を行うことにより測定した.長指伸筋では刺激開始1分後,ヒラメ筋では4分後の張力を測定し,初期値に対するそれらの割合を疲労の指標とした.長指伸筋およびヒラメ筋の疲労耐性は,右心不全群で有意に低下した.筋小胞体Ca2+取り込み速度は,Indo-Ⅰを付加したホモジネートで測定した.その結果,Ca2+取り込み速度は,長指伸筋で25.4%(p<0.01),ヒラメ筋で30.4%(p<0.05)低下した.このCa2+取り込み速度の低下は,筋小胞体Ca2+-ATPaseタンパク量の低下と一致した.筋小胞体Ca2+取り込み能の低下は,筋張力の低下を引き起こし,このCa2+ handlingの低下は,少なくとも右心不全による運動耐容能の低下の一因であろう.In this study, we investigated the hypothesis that right congestive heart failure (CHF) would impair sarcoplasmic reticulum (SR) Ca2+ uptake in skeletal fast- and slow-twitch muscles. To induce CHF, the rats were injected with monocrotalin (30 ㎎/㎏). After 4 weeks of injection, extensor digitorum longus (EDL) and soleus (SOL) muscles were sampled from both hind limbs. Muscle fatigue resistance was measured in vitro as the relative decline in force production of tetanic contraction induced by electrical stimulation over 1 and 4 min in EDL and SOL, respectively. Evaluation of fatigue characteristics showed that CHF significantly reduced fatigue resistance in both muscles under study.SR Ca2+uptake rate wasmeasured in vitro with Indo-I on muscle homogenates. As hypothesized, Ca2+uptake rate was decreasedby 25.4%(P < 0.01) and 30.4%(P < 0.05) in EDL and SOL, respectively. This decline in Ca22+uptake ratewas accompanied by an immunochemically determined decrease in SR Ca2+-ATPase protein. Taking intoaccount previous findings that the depressed SR Ca2+uptake leads to the reduce in muscle forceproduction, these results suggest that impaired SR Ca2+handling capacity in skeletal muscle may accountat least partly for deteriorations in exercise tolerance resulting from right CHF

Distribution and Elimination of Insulin and C-peptide in a Benign Insulinoma Patient

The distribution and elimination of insulin and C-peptide was evaluated in a case of benign insulinoma, using the method of gel chromatography. The significant differences between total Immunoreactive insulin (IRI) level and the level of Peak I plus Peak II of IRI was noticed in splenic vein. This fact suggested that intermediate and/or abnormal IRI could be released from the tumor. In order to diagnose a hypoglycemic patient with completely normal IRI and CPR level in peripheral blood, the gel chromatographic separation of IRI from splenic and/or portal blood could be useful

Characteristics of 5015 Salivary Gland Neoplasms Registered in the Hiroshima Tumor Tissue Registry over a Period of 39 Years

Salivary gland neoplasms are uncommon, and their epidemiology in Japan has not been well described. We conducted a retrospective review of salivary gland tumors registered in the Hiroshima Tumor Tissue Registry over a period of 39 years. The subjects were 5015 cases ranging in age from 6 to 97 (mean, 54.3) years old. The incidence of both benign tumors and malignant tumors increased with age until 60&#8722;69 years and then declined. Among the 5015 salivary gland neoplasms, 3998 (80%) were benign and 1017 (20%) were malignant. Pleomorphic adenoma (PA) was the most frequent benign tumor (68%), followed by Warthin tumor (26%). Adenoid cystic carcinoma (ACC) (27%) and mucoepidermoid carcinoma (MEC) (26%) were the two most frequent malignant tumors. Characteristically, there was a very low incidence of polymorphous adenocarcinoma in Japan. The average annual age-adjusted incidence rate per 100,000 population was 3.3 for benign tumors and 0.8 for malignant tumors. This is the large-scale multi-institutional analysis to describe the characteristics of salivary gland neoplasms, based on the pathological tissue registry data. We hope that the present data can contribute to early diagnosis and effective treatment of salivary gland tumors and to cancer prevention

飼料イネ「Rayada」の実用化に向けた難脱粒性系統の開発

国産の畜産飼料の自給率向上と水田の有効利用の観点から，飼料イネおよび飼料米の栽培が推進されている．飼料イネ栽培では，コストおよび環境負荷低減のために，化学肥料低投下における高い生産性が求められている．バングラデッシュ在来浮稲である「Reyada」は，多回刈栽培下において乾物収量が約2.5kg/m2と極めて高く，また多回刈栽培下における可消化養分総量（TDN)収量も約1.5kg/m2と従来の飼料イネ品種よりも高い値を示すことが報告されている（白ら 2006.　望月ら 2013）．そのため「Rayada」は飼料イネ向きの品種の一つとして有望視されており，特に日長感受性が高く，極晩生品種であることから，台風害の多発する沖縄の水田二期作米の代替として普及が期待されている．しかしながら，Rayadaは日本型栽培水稲に比べて脱粒しやすく，収量の減少やこぼれた種子から漏生苗が発生する可能性があるため，実用化には難脱粒性系統の育成が必要である．そこで本研究ではRayadaの実用化に向け，難脱粒性系統の開発を行った

カリフォルニア産ジャポニカ米中粒種を材料とした食味試験の精度

We conducted the sensory test, using rice grown in State of California, U.S.A. The reliability of the sensory test was examined by statistically analyzing the discerning ability and taste preference of panelists. Multiple regression analysis was performed with the overall eating quality as the criterion variable and each taste evaluation parameter as the explanatory variable. As a result, the parameter of “taste” had the largest contribution to the overall eating quality. Other parameters had low contributions, however, the harder rice pretended to be the lower score. Analysis of variance with line as a replication indicated that 9 out of 24 panelists (about 40%) had a reliable discerning ability. There is no correlation between discerning ability and taste preference (r=-0.062ns). It was different from the previous reports using domestically produced rice that the taste preferences of panelists with high discerning ability were consistent with the overall trend. In our evaluation for California rice, compared with previous reports, there were two different trends: 1) only parameter of “taste” largely contributes to overall eating quality, 2) the taste preference of panelists with high discerning ability were not consistent with overall trend.アメリカ合衆国カリフォルニア州で栽培された中粒種の米の食味試験をおこない，パネリストの識別能力や嗜好性等を統計学的に解析し，食味試験の精度について検討した．総合評価を目的変数，各食味評価項目を説明変数とした重回帰分析をおこなったところ，総合評価に対する寄与が最も大きかったのは「味」であった．その他の項目は寄与が小さかったが，硬い米ほど評価が劣る傾向が認められた．供試系統を反復とした分散分析のF 値でみると，識別能力のあるパネリスト（有意水準10% 以上で系統間差を識別できたパネリスト）は24 名中9 名で約40% であった．識別能力と嗜好性との間には有意な相関は認められなかった（r=-0.062ns）．このことは，識別能力が高いパネリストの嗜好性は全体の傾向と一致するという国産米を扱った複数の報告とは全く異なっていた．このように，本試験では従来の知見とは異なる事例がいくつか見出された．外国産ジャポニカ米を対象とした食味試験の精度を保つには，パネリストの訓練方法や試料のポストハーベストについて特に検討する必要があると考えられた