Airway Expression of Smad7, a TGF-β-inducible Inhibitory Molecule of TGF-β Signaling, Decreases after Repeated Airway Antigen Challenges

Transforming growth factor-β (TGF-β) is a profibrogenic cytokine that is involved in airway remodeling largely associated with chronic asthma. Accordingly, regulators of TGF-β activity could also play some role in airway remodeling in asthma. In this study, we investigated expression of Smad 7, a major intracellular inhibitor of TGF-β signaling, in the airways of mouse models of acute and chronic asthma. Sensitized, repeatedly (14 days) ovalbumin (OVA)-inhaled BALB/c mice exhibited evidence of airway remodeling including prominent subepithelial fibrosis associated with airway hyperresponsiveness (AHR) and airway inflammation (chronic asthma model) whereas sensitized, shortly OVA-inhaled BALB/c mice showed only AHR and airway inflammation (acute asthma model). Immunohistochemical analysis showed that Smad 7 immunoreactivity in the airways was increased after the development of acute and chronic asthma models and mainly detected in bronchial epithelial cells. Interestingly, Smad 7 immunoreactivity was significantly less in the airways of chronic asthma model than in those of acute asthma model, which was also confirmed by real-time PCR analysis of Smad 7. In consistent with decreased Smad 7 expression in the airways of chronic asthma model, phosphorylation of Smad 2, a marker of active TGF-β signaling, was increased in bronchial epithelial cells of chronic asthma model when compared with acute asthma model. These results suggest that decreased Smad 7 expression and Smad 2 upregulation in bronchial epithelial cells might result in increased TGF-β activity and contribute to the development of airway remodeling seen in chronic asthma

Effects of Norepinephrine on Left Ventricular Hemodynamics and Myocardial Blood Flow in Rats with and without Calcium Overload

Heart failure patients have been shown to have an increased blood norepinephrine concentration, and patients with a high norepinephrine concentration have a poor prognosis. Norepinephrine is a catecholamine with α_1 and β_1 effects, which lead to a vasoconstrictive action and enhancement of myocardial contraction. However, the consequences of norepinephrine-induced changes in myocardial blood flow in heart failure patients remain unknown. In this study, the influence of norepinephrine on hemodynamics and blood flow in the left ventricular myocardium was investigated using rats with and without a calcium load. Norepineph-rine without a calcium load induced a 29.3% reduction of myocardial blood flow (MBF), but had no significant effect on ejection fraction (EF) and left ventricular end-diastolic pressure (LVEDP). With simultaneous calcium administration, norepinephrine induced a 33.2% reduction of MBF and increased LVEDP significantly, but caused no reduction in EF. These results suggest that norepinephrine decreases MBF but has no effects on systolic function, and increases LVEDP and decreases MBF more markedly in combination with calcium

Effects of Cytokines and Immunosuppressants on the Production of Serum Amyloid A Protein and C-reactive Protein in HepG2 Cells

C-reactive protein (CRP) and serum amyloid A protein (SAA) are acute- phase proteins produced by the liver in response to inflammatory cytokines. The concentrations of these proteins in serum vary in parallel in most pathological conditions, but sometimes vary independently. CRP and SAA were determined in HepG2 cell culture medium supplemented with five immunosuppressants (corticosteroid, gusperimus hydrochloride, cyclosporin A, mizoribine and tacrolimus hydrate), with or without interleukin-1β(IL-1β) and interleukin-6 (IL-6). We also examined the effects of the immunosuppressants on the production of cytokines and changes in CRP and SAA production in HepG2 cells stimulated with the culture fluid from lipopolysaccharide (LPS) - treated monocytes. In HepG2 cells, production of CRP and SAA was greatly affected by IL-6 and IL-β, respectively. Prednisolone (PSL) suppressed CRP production, while it enhanced SAA production. The other four immunosuppressants did not affect CRP production, but inhibited SAA production. PSL significantly inhibited cytokine production in monocytes, while the other immunosuppressants enhanced it. In HepG2 cells incubated with the culture fluid from LPS-stimulated monocytes, CRP production was suppressed, while SAA production was enhanced. PSL suppressed CRP production in HepG2 cells by inhibiting IL-6 production in monocytes, whereas PSL increased SAA production through a direct action on the hepatoma cells. In contrast, the other immunosuppressive agents enhanced IL-β production in monocytes. The agents induced SAA production in the HepG2 cells but did not affect CRP production

A Novel Cardioprotective Drug, K201 (JTV519), Induces Prolongation of QT and QTc Intervals, but not Torsades de Pointes

K201 (JTV-519; 4-[-3{1-(4-benzyl) piperidinyl} propionyl]-7-methoxy-2, 3, 4, 5-tetrahydro-1, 4-ben-zothiazepine), is a multi-channel blocker and a ryanodine receptor stabilizer that exhibits strong cardiopro-tective and antiarrhythmic effects. In this study, we examined how intravenous infusion of K201 without an α-agonist prolongs the QT interval in chloralose-anaesthetized rabbits, and whether the maximum dose of K201 given concomitantly induces torsades de pointes. The QT interval was significantly prolonged in the group receiving 6-hour infusion of K201 at 20 μg/kg/min, but the QTc interval was not prolonged (n=5). With infusion of K201 at 0 (vehicle; n=5), 40 (n=6), 100 (n=6), 200 (n=6) and 400 μg/kg/min (n=5), blood pressure and HR were decreased, and prolongation of PQ, QRS complex, QT and QTc intervals occurred dose-dependently. The QTc interval was significantly prolonged from 211.5±11.9 ms of the baseline to 319.9±31.1 ms at a concentration of 400 μg/kg/min, which is the maximum dose of K201, but tors-ades de pointes was not induced at this dose. These results show that K201, which has a suppressive effect on Ca^ leakage from the sarcoplasmic reticulum and an α_1-adrenoceptor-blocking effect, does not induce torsades de pointes, although it causes prolongation of the QT interval

ケッセイ シンキン マーカー ソクテイ セイド ト ユウヨウセイ

当院臨床検査部では,依頼された検査が診療に役立つように精度管理を徹底し,検査方法の改善や測定の迅速化などを検討している.今回,心筋トロポニンIとT(cTnIとcTnT),ミオグロビン(Mb),CK-MB蛋白(CK-MB mass),CK-MB活性測定(CK-MB),心房ナトリウム利尿ペプチド(ANP),脳性ナトリウム利尿ペプチド(BNP)の検査方法,精度,特性について急性及び慢性心疾患患者の依頼検体265試料を用いて検討した.その結果,cTnIはcTnTと良好な相関関係を示し,測定値はcTnTに比べ約8倍の高値を認めた.急性心筋梗塞(AMI)患者検体のcTnI,Mb,CK-MB massおよびCK-MBは良好な変動を示した.cTnTはcTnIに比べると上昇率が小さく変動も少なかったが,Cut off値と比較するとほぼ同様な変化を認めた.AMI以外の慢性心疾患でもcTnI,CK-MB mass,ANP,BNPは基準値を超える測定値を示した.今回の結果から,心疾患の潜在的な進行や悪化が疑われた場合はcTnIとBNPの測定が他の心筋マーカーと同様に有意義であり,今後も検査部では優れた測定精度と迅速な検査法の検討を続ける必要があることが示唆された.Our goals are to maintain the accuracy of various medical tests, to improve test methods, and to reduce the measurement time. In this study we examined the method, accuracy and time required for measurement of cardiac troponins (cTnT and cTnI), myoglobin (Mb), CK- MB protein mass (CK-MB mass), atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) using 265 samples of patients with acute and chronic heart disease. The coefficient of variation (C.V%) was measured of cTnI (1.9%, 2.2%), cTnT (2.4%, 2.5%), Mb (1.2%, 1.7%), CK-MBmass (1.6%, 2.6%), ANP (5.6%, 7.6%) and BNP (7.1%, 9.4%), and CK-MB (2.1%). cTnI had a good correlation with cTnT (r=0.845, P<0.001 ; n=120) and showed approximately 8-fold high concentrations compared with cTnT. In patients with acute myocardial infarction (AMI), changes in cTnI, Mb and CK-MB mass showed good sensitivity in the early stage, whereas cTnT showed little change. cTnI, CK-MB mass, ANP and BNP were also mostly positive in patients with chronic heart disease, excluding AMI. The results of this study considered that measurement of cardiac markers is useful in patients with heart disease. The sensitivity, accuracy and measurement time for such assays should be further improved, and the utility of the assay items should be evaluated

ラット ニオケル カルシウム フカカ ノ ノルエピネフリン ニヨル キュウセイ サシツ カクチョウ ショウガイ : サシツ ケッコウ ドウタイ ナラビニ シンゾウ チョウオンパホウ ニヨル ケントウ

拡張不全は左室収縮の低下を伴わない心不全で,左室収縮の低下による収縮不全とは病態,基礎疾患,予後が異なることが明らかにされつつある.しかし,その発生メカニズムについては十分に解明されていない.本研究では雄性ラット42匹を用い,対照群,塩化カルシウム投与群,ノルエピネフリン投与群,塩化カルシウム投与後,塩化カルシウム+ノルエピネフリン投与群において,左室血行動態,左室拡張障害について検討をおこなった.4群でチップ付き圧カテーテルを左室内へ挿入し,また別の4群で心臓超音波法により左室駆出率を測定した.さらに別に拡張早期急速流人期血流速波形(E波),拡張後期流人速波形(A波),E波減速時間(DCT),組織ドプラ法で拡張早期僧帽弁輪速度(Ea波)を測定した.その結果,塩化カルシウム群,ノルエピネフリン群では左室拡張末期圧は変化を認めなかったが,塩化カルシウム+ノルエピネフリン投与群で左室拡張末期圧は著しい上昇を認めた.また,塩化カルシウム+ノルエピネフリン群では左室駆出率は対照群と有意差を認めなかったが,E波,DCT,Ea波は対照群に比し有意な減少を認めた.以上より,塩化カルシウム負荷下でのノルエピネフリン投与で急激な心臓拡張障害が惹起され,心臓の拡張障害の発生にノルエピネフリンが関与している可能性が示唆された.In diastolic dysfunction, cardiac cells in the diastolic phase do not rapidly or completely return to the normal state of relaxation. However, the detailed mechanism remains unknown. To develop an acute diastolic dysfunction model in the rat, norepinephrine (30μg/kg/min) with calcium (12mg/kg/min) was administered for 20 minutes, following 20-minute administration of calcium, compared with the control group. A cardiovascular mikro-tip pressure transducer catheter was inserted into the left ventricle, and the intraventricular pressure and left ventricular end-diastolic pressure were determined. Early diastolic mitral annular velocity (Ea), E and A waves, deceleration time (DCT) and left ventricular ejection fraction were estimated using tissue Doppler imaging and echocardiography. In the norepinephrine with calcium group, no significant change in left ventricular pressure was found, but left ventricular end-diastolic pressure was markedly increased. On echocardiography, no change was found in left ventricular ejection fraction, but the E wave, DCT and Ea wave were decreased, in comparison with the control, calcium alone and norepinephrine alone groups. The results of this study could indicate that norepinephrine administration with calcium causes acute diastolic dysfunction in the rat