SEA0400 fails to alter the magnitude of intracellular Ca2+ transients and contractions in Langendorff-perfused guinea pig heart

SEA0400 is a recently developed inhibitor of the Na(+)/Ca(2+) exchanger (NCX) shown to suppress both forward and reverse mode operation of NCX. Present experiments were designed to study the effect of partial blockade of NCX on Ca handling and contractility in Langendorff-perfused guinea pig hearts loaded with the fluorescent Ca-sensitive dye fura-2. Left ventricular pressure and intracellular calcium concentration ([Ca(2+)](i)) were synchronously recorded before and after cumulative superfusion with 0.3 and 1 muM SEA0400. SEA0400 caused no significant change in the systolic and diastolic values of left ventricular pressure and [Ca(2+)](i). Accordingly, pulse pressure and amplitude of the [Ca(2+)](i) transient also remained unchanged in the presence of SEA0400. SEA0400 had no influence either on the time required to reach peak values of pressure and [Ca(2+)](i) or on half relaxation time. On the other hand, both 0.3 and 1 muM SEA0400 significantly increased the decay time constant of [Ca(2+)](i) transients, obtained by fitting its descending limb between 30% and 90% of relaxation, from 127 +/- 7 to 165 +/- 7 and 177 +/- 14 ms, respectively (P < 0.05, n = 6). In contrast to the guinea pig hearts, rat hearts responded to SEA0400 treatment with increased [Ca(2+)](i) transients and contractility. These interspecies differences observed in the effect of SEA0400 can be explained by the known differences in calcium handling between the two species.     

张力平衡针法改善脑卒中痉挛瘫痪患者残损功能的临床评价

目的:观察张力平衡针法对脑卒中痉挛瘫痪患者残损功能的影响。方法:选择脑卒中痉挛瘫痪患者106例,随机分为张力平衡针法组(54例)、常规针法组(52例)。张力平衡针法组采用张力平衡针法,分别于上、下肢伸肌、屈肌处取穴,常规针法组采用常规针法,穴取肩髃、曲池、外关等,于治疗前后评定患者肌力、肌张力、肌痉挛状态及关节活动度的变化。结果:治疗30天后,张力平衡针法组总有效率为96.3%(52/54),优于常规针法组的84.6%(44/52)(P0.01)。与治疗前比较,两组患者肌力、肌张力评分、肌痉挛状态评分、关节活动度均增加,张力平衡针法组与常规针法组比较改善更显著(均P0.05)。结论:张力平衡针法能显著改善脑卒中痉挛瘫痪患者的肌力、肌张力、肌痉挛状态和增加关节活动度。     

Metformin attenuates motility,contraction,and fibrogenic response of hepatic stellate cells in vivo and in vitro by activating AMP-activated protein kinase

AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.     

Reduced contraction stress formation obtained by a two-step cementation procedure for fiber posts

Objectives

In a previous study, a 60% increase in push-out strength was obtained in vitro with a two-step cementation of fiber posts, a procedure equivalent to the layering technique of composite restorations. The aim of this study is to find the rationale for this increase in push-out strength with finite element analysis (FEA).

Methods

FEA models were created of the push-out test set-up of fiber posts cemented according to a one-step and two-step procedure and of the complete root with post. The failure loads of glass-fiber posts cemented with RelyX Unicem as obtained in a previous study were used as the load in the push-out FEA models. For the complete root model, a load of 100 N was used. The stresses due to the shrinkage of the cement layer and the applied load were determined for the one-step and two-step procedure of the push-out test specimens and for the one-step procedure of the complete root.

Results

Even though the load in the two-step push-out model was 60% higher compared to the one-step model, the combined stresses were comparable. The stresses due to shrinkage alone in the complete root approached or exceeded the bond strength of resin cements to dentin in the coronal and apical areas.

Significance

FEA of this test set-up explains the results of the in vitro study. Two-step cementation of fiber posts leads to a decrease in internal stresses in the restoration which results in higher failure loads and possibly in less microleakage.     

Training augments resistance exercise induced elevation of circulating brain derived neurotrophic factor (BDNF)

Brain derived neurotrophic factor (BDNF) is postulated to be an important mediator of exercise-induced neuroprotection. We tested the hypothesis that resistance exercise elevates circulating BDNF. Twenty healthy untrained college-aged males underwent a 5-week traditional or eccentric-enhanced progressive resistance training intervention. Blood was acquired at rest and 1, 30, and 60 min following a standardized resistance exercise testing bout performed at baseline and at the completion of the intervention. Serum BDNF responses did not differ between the two groups at any time point during baseline or post-intervention testing; thus, all values were combined into a single cohort for further analysis. Resting BDNF was not altered by the exercise training intervention [23,304 ± 1835 pg/ml (baseline) vs. 19,433 ± 1992 pg/ml (post-intervention)]. Following the baseline resistance exercise bout, serum BDNF increased 32% (p < 0.05) and was gradually reduced to 41% below resting levels at 60 min into recovery (p < 0.01). During post-intervention testing, serum BDNF increased 77% in response to the standardized resistance exercise bout (p < 0.01) and returned to resting values within 30 min. Ultimately, the change in serum BDNF from rest to immediately post-exercise was 98% greater at post-intervention than at baseline (p < 0.05). Our study is the first to demonstrate that resistance exercise induces a robust, yet transient, elevation of circulating BDNF and that progressive resistance training augments this response; perhaps demonstrating one mechanism through which exercise influences brain health.     

Effect of thienorphine on intestinal transit and isolated guinea-pig ileum contraction

AIM: To evaluate the effect of thienorphine on small intestinal transit in vivo and on guinea-pig ileum (GPI) contraction in vitro . METHODS: The effects of thienorphine on intestinal transit were examined in mice and in isolated GPI. Buprenorphine and morphine served as controls. The distance traveled by the head of the charchol and the total length of the intestine were measured in vivo . Gastrointestinal transit was expressed as a percentage of the distance traveled by the head of the marker relative to the total length of the small intestine. The isolated GPI preparations were connected to an isotonic force transducer and equilibrated for at least 1 h before exposure to drugs. Acetylcholine was used for muscle stimulation. RESULTS: Thienorphine (0.005-1.0 mg/kg, ig ) or bu-prenorphine (0.005-1.0 mg/kg, sc ) dose-dependently significantly inhibited gut transit compared with saline. Thienorphine inhibited gut transit less than buprenorphine. The maximum inhibition by thienorphine on the intestinal transit was 50%-60%, whereas the maximum inhibition by morphine on gut transit was about 100%. Thienorphine also exhibited less inhibition on acetylcholine-induced contraction of GPI, with a maximum inhibition of 65%, compared with 93% inhibition by buprenorphine and 100% inhibition by morphine. Thienorphine induced a concentration-dependent decrease in the basal tonus of spontaneous movement of the GPI, the effect of which was weaker than that with buprenorphine. The duration of the effect of thienorphine on the GPI was longer than that with buprenorphine. CONCLUSION: Thienorphine had less influence, but a longer duration of action on GPI contraction and moderately inhibited intestinal transit.     

Carbon monoxide contributes to the constipating effects of granisetron in rat colon

AIM To investigate the mechanisms underlying the potential contribution of the heme oxygenase/carbon monoxide(HO/CO) pathway in the constipating effects of granisetron. METHODS For in vivo studies, gastrointestinal motility was evaluated in male rats acutely treated with granisetron [25, 50, 75 μg/kg/subcutaneous(sc)], zinc protoporphyrin IX [Zn PPIX, 50 μg/kg/intraperitoneal(ip)] and hemin(50 μmol/L/kg/ip), alone or in combination. For in vitro studies, the contractile neurogenic response to electrical field stimulation(EFS, 3, 5, 10 Hz, 14 V, 1 ms, pulse trains lasting 10 s), as well as the contractile myogenic response to acetylcholine(ACh, 0.1-100 μmol/L) were evaluated on colon specimens incubated with granisetron(3 μmol/L, 15 min), Zn PPIX(10 μmol/L, 60 min) or CO-releasing molecule-3(CORM-3, 100, 200, 400 μmol/L) alone or in combination. These experiments were performed under co-treatment withor without atropine(3 μmol/L, a muscarinic receptor antagonist) or NG-nitro-L-Arginine(L-NNA, 100 μmol/L, a nitric oxide synthase inhibitor).RESULTS Administration of granisetron(50, 75 μg/kg) in vivo significantly increased the time to first defecation(P = 0.045 vs vehicle-treated rats), clearly suggesting a constipating effect of this drug. Although administration of Zn PPIX or hemin alone had no effect on this gastrointestinal motility parameter, Zn PPIX co-administered with granisetron abolished the granisetron-induced constipation. On the other hand, co-administration of hemin and granisetron did not modify the increased constipation observed under granisetron alone. When administered in vitro, granisetron alone(3 μmol/L) did not significantly modify the colon's contractile response to either EFS or ACh. Incubation with Zn PPIX alone(10 μmol/L) significantly reduced the colon's contractile response to EFS(P = 0.016) but had no effect on contractile response to ACh. Co-administration of Zn PPIX and atropine(3 μmol/L) abolished the Zn PPIX-mediated decrease in contractile response to EFS. Conversely, incubation with CORM-3(400 μmol/L) alone increased both the contractile response to EFS at 10 Hz(10 Hz: 71.02 ± 19.16 vs 116.25 ± 53.70, P = 0.01) and the contractile response to ACh(100 μmol/L)(P = 0.012). Co-administration of atropine abolished the CORM-3-mediated effects on the EFS-mediated response. When granisetron was co-incubated in vitro with ZnP PIX, the ZnP PIX-mediated decrease in colon contractile response to EFS was lost. On the other hand, co-incubation of granisetron and CORM-3(400 μmol/L) further increased the colon's contractile response to EFS(at 5 Hz: P = 0.007; at 10 Hz: P = 0.001) and to ACh(ACh 10 μmol/L: P = 0.001; ACh 100 μmol/L: P = 0.001) elicited by CORM-3 alone. L-NNA co-administered with granisetron and CORM-3 abolished the potentiating effect of CORM-3 on granisetron on both the EFSinduced and ACh-induced contractile response.CONCLUSION Taken together, findings from in vivo and in vitro studies suggest that the HO/CO pathway is involved in the constipating effects of granisetron.     

布托啡诺镇痛对清宫术后子宫收缩痛的影响

目的评价布托啡诺镇痛减轻清宫术后子宫收缩痛的效果。方法 ASAⅠ~Ⅱ级清宫手术患者120例,随机分为B组(60例)和P组(60例)。B组先缓慢静脉注射布托啡诺0.5 mg,2 min后静脉注射丙泊酚2~2.5 mg/kg;P组单独静脉注射丙泊酚2~2.5 mg/kg。两组丙泊酚静注速率均为200 mg/min。结果 B组患者苏醒即刻、苏醒后15 min及30 min宫缩痛的VAS评分分别为(2.1±0.9)、(6.5±1.4)及(1.2±0.6)分,明显低于P组的(8.9±1.7)(、34.4±2.5)及(6.1±1.6)分(P0.05)。结论布托啡诺镇痛能减轻清宫术后的子宫收缩痛。     

神经——肌肉继发性兴奋的时间总和——“循经感传”机制研究（Ⅲ）

实验用离体的坐骨神经－－腓肠肌组织和后肢的坐骨神经及其分支、腓 肠肌、趾长伸肌－胫前肌。结果证明,刺激坐骨神经引起的腓肠肌纤维兴奋过程中的去极化电位形成的综合电流能刺激穿刺该肌的神经,引起该神经支配的肌肉继发性兴奋反应,交引起继发性神经－肌肉反应的刺激电流降至阈值强度。连续2个或更多的脉冲刺激（间隔在10－1000ms之间）可发生时间总和的激活反应。这种时间总和效应有助于解番沿经脉感觉慢速迁移现象。     

心力衰竭蒙医寒证热证模型的建立及评价

目的：研究心力衰竭（简称心衰）蒙医寒证、热证模型的建立方法及其评价。方法：将68只（雌雄各半）Wistar大鼠随机分为正常对照组（CON）8只,阿霉素心衰模型组（ADR）12只,阿霉素+冰水心衰寒证模型组（ADR+IW）12只,阿霉素+阿魏、肉桂心衰热证模型组（ADR+MY）12只,冰水心衰寒证模型组（IW）12只,阿魏、肉桂心衰热证模型组（MY）12只等6组。ADR组给于腹腔注射盐酸阿霉素针剂;ADR+IW组给予腹腔注射盐酸阿霉素针剂同时,冰水（0℃）灌胃建立心衰寒证模型,ADR+MY组予腹腔注射盐酸阿霉素针剂同时,阿魏+肉桂灌胃建立心衰热证模型,IW组给予冰水（0℃）灌胃建立心衰寒证模型, MY组予阿魏+肉桂灌胃建立心衰热证模型,CON组给予等量生理盐水灌胃,干预6周后做心脏彩超、取材。将心肌组织做苏木精-伊红（HE）染色 、检测血清N末端B型利钠肽前体（NT-proBNP）及心肌酶变化,检测心肌组织钠、钾-三磷酸腺苷酶（Na+-K+-ATP）,钙-三磷酸腺苷酶（Ca2+-ATP）活性及琥珀酸脱氢酶（SDH）活性。结果：与CON组比较,5种模型组大鼠体重均显著下降（P<0.01）;与ADR+IW组比较,ADR和ADR+MY组大鼠体重均显著下降（P<0.05）、MY组大鼠体重下降,但无明显差异（P>0.05）;与ADR+MY比较,ADR+IW和IW组大鼠体重均显著增高（P<0.05,P<0.01）;与IW比较,ADR组大鼠体重显著下降（P<0.01）、MY组大鼠体重下降,但无显著差异（P>0.05）。与CON组比较,ADR+IW和IW组大鼠体温显著下降（P<0.01）;ADR+MY和MY组大鼠体温显著升高（P<0.01）;与ADR+IW比较,ADR、ADR+MY及MY组大鼠体温显著升高（P<0.01）,与ADR+MY比较,ADR、ADR+IW及IW组大鼠体温显著下降（P<0.01）;与IW比较,ADR和MY组大鼠体温显著升高（P<0.01）。与CON组比较,5个模型组血清NT-proBNP明显升高（P<0.05,P<0.01）;与CON组比较,5个模型组心肌酶各项指标出现不同程度升高;与CON组比较,5个模型组心脏彩超EF%、FS%显著降低（P<0.01）,而LVIDs值显著升高（P<0.01）,且ADR、ADR+IW及ADR+MY组各值降达到心衰水平。心肌组织HE染色结果示,各模型组大鼠心肌细胞出现不同程度病理变化,其中ADR+IW、ADR+MY大鼠组心肌细胞排列紊乱、丧失正常细胞结构、炎性细胞浸润,出现心肌纤维化,而病变程度依次为： ADR+IW>ADR>ADR+MY,IW和 MY组大鼠只出现心肌细胞排列紊乱。与CON组比较,ADR+MY和MY组大鼠心肌组织Ca2+-ATP和SDH等酶活性均显著升高（P<0.01）,而ADR+IW和IW组的显著下降（P<0.01）;与CON组比较,ADR+MY组大鼠心肌组织Na+-K+-ATP酶活性显著升高（P<0.01）,而ADR+IW和IW组的显著下降（P<0.01）、MY组的无显著差异（P>0.05）;与ADR+IW比较,ADR、ADR+MY和MY组心肌细胞Na+-K+-ATP、Ca2+-ATP及SDH等酶活性显著升高（P<0.01）;与ADR+MY比较,ADR 、ADR+IW及IW组大鼠心肌细胞Na+-K+-ATP、Ca2+-ATP及SDH等酶活性显著降低（P<0.01）,与IW组比较,MY组ATP和SDH酶活性明显降低（P<0.01）。结论：注射盐酸阿霉素的同时给予冰水和阿魏+肉桂能成功建立心衰寒证和热证模型,模型成功模拟心衰寒证、心衰热证的临床症状及病理组织学变化。采取该方法建立的心衰寒证和心衰热证动物模型可行,为本病症的研究提供了准确、客观、有效的动物模型的建立及评价方法。