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991.
Marcos H Toyama Sérgio Marangoni José C Novello Gildo B Leite Julia Prado-Franceschi Maria Alice da Cruz-H?fling Léa Rodrigues-Simioni 《Toxicon》2003,41(4):493-500
Two major crotamine isoforms (F22 and F32) were obtained after three chromatographic steps and were assayed in mouse phrenic nerve-diaphragm preparations. F32 and F22 (0.5 microg/ml, n=4) produced a facilitatory effect, which increased isometric twitch-tension by 300 and 230%, respectively, after a 120 min incubation. At a concentration of 0.1 microg/ml, both isoforms increased the twitch-tension by about 160%. However, when the isoforms were co-incubated (final concentration, 0.5 microg/ml) for 30 min prior to testing, they did not cause the facilitation seen with > or =0.1 microg/ml of each isoform alone. Histologically, F32 and F22 at 0.5 and 1 microg/ml were quantitatively alike in inducing tissue myonecrosis. However, a mixture of the two isoforms (final concentration, 0.5 microg/ml) significantly attenuated the damage seen with either toxin alone. Mass spectrometry analysis showed that the isoforms had the same molecular mass (4.8 kDa) and that they existed as monomers with a highly stable structure. These results indicate that F22 and F32 acted on muscle cells of the mouse phrenic-nerve diaphragm preparation through similar mechanisms. Since the isoforms did not produce the expected summation in the increase in muscle twitch-tension, it is possible that they may have different affinities for the sodium channel subunits. 相似文献
992.
ZHANG Guang-Qin HAO Xue-Mei DAI De-Zai FU Yu ZHOU Pei-Ai WU Cai-Hong Research Division of Pharmacology China Pharmaceutical University Nanjing China ~National Laboratorv of Biomembrane Membrane Biotechnology College of Life Sciences Peking University Beijing China 《Acta pharmacologica Sinica》2003,(12)
AIM: To study the effect of puerarin (Pue) on Na~+ channel in rat ventricular myocytes. METHODS: Whole-cell patch-clamp technique was applied on isolated cardiomyocytes from rats. RESULTS: Pue inhibited cardiac I_(Na) in a positive rate-dependent and dose-dependent manner, with an IC_(50) of 349 μmol/L. The kinetics of blockage of cardiac sodium channel by Pue resembled the ClassIa/Ic of antiarrhythmic agents. Pue 300 μmol/L did not alter the shape of the I-V curve of I_(Na), but markedly shifted the steady-state inactivation curve of I_(Na) towards more negative potential by 15.9 mV, and postponed the recovery of I_(Na) inactivation state from (21.9±1.6) ms to (54.4±3.4) ms (P<0.01 ). It demonstrated that the steady state of inactivation was affected by Pue significantly. CONCLUSION: Pue protected ventricular myocytes against cardiac damage and arrhythmias by inhibiting recovery from inactivation of cardiac Na~+ channels. 相似文献
993.
Involvement of CDK4, pRB, and E2F1 in ginsenoside Rg_1 protecting rat cortical neurons from β-amyloid-induced apoptosis 总被引:2,自引:0,他引:2
CHEN Xiao-Chun CHEN Li-Min ZHU Yuan-Gui FANG Fang ZHOU Yi-Can ZHAO Chao-Hui Fujian Institute of Geriatrics Union Hospital Fujian Medical University Fuzhou China 《Acta pharmacologica Sinica》2003,(12)
AIM: To explore the possible mechanism of β-amyloid (Aβ)-induced apoptosis in rat cortical neurons and the protective effect of ginsenoside Rg_1. METHODS: AO-EB staining was used to quantify the apoptotic cells. DNA fragmentation was observed by gel electrophoresis. The levels of cyclin-dependent kinases-4 (CDK4) and phosphorylated pRB were detected by Western blot. RT-PCR was used to examine the expression of E2FI mRNA. RESULTS: Treatment with Aβ_(1-40) at the concentration of 20, 40, 80 mg/L for 48 h induced rat cortical neuron poptosis from 12.5%±1.5%(control) to 22.3%±1.4%, 38.8%±1.3%, 36.7%±1.4%, respectively. Pretreatment with Rg_1 at the dose of 0.5, 1, 2, 4, 8, 16 μmol/L for 24 h, then treatment with Aβ_(1-40)40 mg/L for 24 h, the percentage of apoptotic neurons decreased from 38.8%±1.3% to 14.5%±1.3%, 13.3%±1.0%, 11.6%±0.29%, 11.8%±1.0%, 6.2%±0.8%, 5.8%±0.8%, respectively. After treatment with Aβ_(1-40)40 mg/L for 24 h, there were transient increases in CD 相似文献
994.
Bitar R Flores O Reverte M López-Novoa JM Macías JF 《International urology and nephrology》2000,32(2):165-169
This study analysed the effect of low doses ofverapamil added to chronic treatment withangiotensin-converting enzyme (ACE)
inhibitors onblood pressure and serum creatinine levels in eightelderly hypertensive patients who had a steadyincrease of
serum creatinine while on ACE inhibitors.The study was performed in eight elderly hypertensivesubjects, five men and three
women (mean age 70 ±2 years; systolic blood pressure 173 ± 4 mmHg; diastolic blood pressure 99 ± 1 mm Hg) andserum creatinine
of 1.60 ± 0.27 mg/dl beforetreatment. During an average of 25 weeks, ACEinhibitors significantly reduced both systolic anddiastolic
blood pressures, but serum creatinine levelswere increased over basal levels (0,68 ± 0,20 mg/dl, p < 0.05). During an average of 10 weeks,the addition of verapamil did not decrease bloodpressure further, but serum creatinine
levels werereduced to baseline. Our study suggests that theaddition of verapamil to ACE inhibitors can reverseACE-induced
increase in creatinine levels in elderlyhypertensive patients in whom this side effect isobserved.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
995.
GM(1,1)灰色模型在尘肺患病人数预测的应用与评价 总被引:1,自引:0,他引:1
目的 探讨验证灰色模型在尘肺患病人数预测的应用效果。方法 利用该煤矿1996~1986年尘肺患病人数进行建模,并建立了数学模型X(I)=583e^0.038(T-II)-452,作外推预测验证。结果 该灰色预测模型的拟合程度较高,取得了较好的效果。结论 灰色模型可应用于尘肺患病人数的预测。 相似文献
996.
997.
998.
胃粘膜表皮生长因子受体在胃溃疡愈合中的表达 总被引:5,自引:0,他引:5
目的 探讨人胃溃疡愈合过程中表皮生长因子受体(EGFR)表达的变化及其作用。方法 采用免疫组化方法,对正常胃粘膜(8例)、胃溃疡活动期(GA组10例)、愈合期(GH组10)例)、瘢痕期(GS组10例)组织的EGFR的表达进行定位观察和图像分析。结果GA组胃粘膜GEFR蛋白质和mRNA的表达均较正常时增加,GH及GS组更加明显。结论 在人胃溃疡愈合过程中,胃粘膜EGFR的表达由弱到强。 相似文献
999.
Vázquez Rueda F Moñiz Mora MV Salas Molina J Pizarro de Celis FJ Ocaña Losa JM 《Actas urologicas espa?olas》2000,24(3):260-261
We report a new case of spermatic cord lymphangioma in a infant 2 years old. The initial diagnosis was funicular hydrocele. The treatment was the local excision of tumor and the diagnostic was histological. Postoperative course was excellent. Must be explored the transillumination of the mass which would have led us to think other the diagnosis different from that of the cord hydrocele before the operation since it would have given negative. During the operation, must the assured that the cystic anomaly is limited to spermatic cord, to evite recurrences in the postoperative course. 相似文献
1000.
Domínguez Domínguez M Reina Ruiz C Blasco Hernández P Espinosa Olmedo J Conde Sánchez JM Vega Toro P García Pérez M 《Actas urologicas espa?olas》2000,24(3):219-222
Contribution of a retrospective series of 16 patients with type II absorptive hypercalciuria over a total of 1.041 patients undergoing metabolic study due to relapsing renal lithiasis. Clinical history of lithiasis, biochemistry prior to treatment and instituted therapy were examined in all cases. Stones composition, radiologic appearance of lithiasis and evolution of biochemical parameters after medical treatment with a mixture of phosphates were also studied. 相似文献