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排序方式: 共有253条查询结果,搜索用时 15 毫秒
1.
羟甲芬太尼(I)是一个新的高强度高选择性阿片μ受体激动剂。本文用cis-A-N-[1-(2-羟基-2-苯乙基)-3-甲基-4-哌啶基]-苯胺(II)或cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶基]-苯胺(III)作为前体合成了[11C]-羟甲芬太尼,以便用正电子发射断层扫描(PET)来观察μ受体。通过水解cis-A-羟甲芬太尼(I)和cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶]-N-苯基丙酰胺(cis-IV)的4-N-丙酰基分别获得II和III。溴乙烷的格氏试剂与回旋加速器产生的[11C]-二氧化碳反应后继而直接加入邻苯二甲酸二酰氯和2,6-二叔丁基吡啶生成同位素标记中间体[11C]-丙酰氯。[11C]-丙酰氯与OH-前体(II)反应后再经HPLC分离纯化直接得[11C]-羟甲芬太尼;[11C]-丙酰氯与酮-前体(III)反应后,再用硼氢化钠甲醇溶液处理,然后进行HPLC分离纯化得[11C]-羟甲芬太尼。两种方法均可获得ll.1~14.8GBq/μmol的特异性放射化学纯[11C]-羟甲芬太尼。总共耗时为40~50min(EOB)。 相似文献
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Intestinal obstruction proximal to a transition zone without an interposed physical barrier usually indicates Hirschsprung disease. The authors report one case of focal small bowel muscular thinning just distal to a transition zone that produced clinical and radiographic findings that simulated long-segment Hirschsprung disease in a 2-day-old infant. 相似文献
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Tarsometatarsal joint: anatomic details on MR images 总被引:3,自引:0,他引:3
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IS Park H Kiyomoto F Alvarez YC Xu HE Abboud SL Abboud 《American journal of kidney diseases》1998,32(6):1000-1010
The renal insulin-like growth factor-I (IGF-I) system has been implicated in the pathogenesis of renal hypertrophy, altered hemodynamics, and extracellular matrix expansion associated with early diabetes. The relative abundance of IGF binding proteins (IGFBPs) in the renal microenvironment may modulate IGF-I actions. However, the precise IGFBPs expressed in the glomerular and tubulointerstitial compartments during diabetic renal growth have not been characterized. In the present study, in situ hybridization studies were performed to examine the expression of IGFBP-1 to -6 messenger RNAs (mRNAs) 3, 7, and 14 days after streptozotocin (STZ) injection in rats. In control, nondiabetic kidneys, all six IGFBP mRNAs were differentially expressed with a predominance of IGFBP-5. The onset of renal hypertrophy in STZ-induced diabetes was associated with a rapid and site-specific induction of IGFBP-1, -3, and -5 mRNAs. In contrast, basal expression of IGFBP-2, -4, and -6 mRNAs was not altered in diabetic rats. IGFBP-5 mRNA expression increased in diabetic glomeruli, cortical, and inner medullary peritubular interstitial cells at days 3, 7, and 14. Although normal glomeruli failed to express IGFBP-3, it was induced concomitantly with IGFBP-5 in diabetic glomeruli and cortical peritubular interstitial cells. IGFBP-1 mRNA levels also increased in cortical tubular cells at each time point tested. Peak induction of IGFBP-3 and -5 was observed at day 3, whereas IGFBP-1 was delayed until day 7. IGFBP-1, -3, and -5 mRNA levels declined by day 14, but remained persistently elevated above control. By immunoperoxidase staining, similar alterations in the pattern of IGFBP-3 and -5 protein expression were observed at each time point. The preferential and site-specific increase in IGFBP-1, -3, and -5 suggest that these IGFBPs may regulate the local autocrine and/or paracrine actions of IGF-I and contribute to the pathogenesis of the early manifestations of diabetic nephropathy. 相似文献
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Pal L; Leykin L; Schifren JL; Isaacson KB; Chang YC; Nikruil N; Chen Z; Toth TL 《Human reproduction (Oxford, England)》1998,13(7):1837-1840
A case series of eight cycles of in-vitro fertilization (IVF) in five women
diagnosed with malignant disorders is presented. These patients chose to
defer definitive treatment for a chance for preservation of potential
fertility. The response of these patients to ovarian stimulation, and the
outcome, was compared with 17 IVF cycles in 12 age- matched patients with
isolated tubal infertility. An apparent adverse influence of malignant
disease on the quality and behaviour of oocytes was observed. Despite a
comparable total number of oocytes per cycle in the two groups, a
significantly reduced percentage of mature oocytes was retrieved per cycle
from patients with malignant diseases. The oocytes from patients with
malignant disorders were of a poorer quality and exhibited a significantly
impaired fertilization rate compared to the controls. We propose that
neoplastic processes, irrespective of the site or cell of origin, may have
a detrimental impact on the biology of oocytes, an effect akin to that seen
on spermatozoa in men with certain malignancies.
相似文献
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Yang PY Almofti MR Lu L Kang H Zhang J Li TJ Rui YC Sun LN Chen WS 《第二军医大学学报》2006,27(6):637-637
Polygonum multiflorum stilbeneglycoside (PMS) is a water-soluble fraction of Polygonum multiflorum Thunb. , one of the most famous tonic traditional Chinese medicines, that has protective effects on the cardiovascular system. The purpose of the present study is to elucidate the effects of PMS on macrophage-derived foam cell functions and the reduction of severity of atherosclerosis in hypercholesterolemic New Zealand White (NZW) rabbits. NZW rabbits were fed for 12 weeks with a normal diet, a high cholesterol diet, or a high cholesterol diet associated with irrigation with different doses of PMS (25, 50, or 100 mg/kg). Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area, respectively. In U937 foam cells, PMS could decrease the high expression of intercellular adhesion molecule (ICAM)-1 protein and the vascular endothelial growth factor (VEGF) protein levels in the medium induced by oxidized lipoprotein when analyzed by flow cytometry. The results proved that PMS is a powerful agent against atherosclerosis and that PMS action could possibly be through the inhibition of the expression of ICAM-1 and VEGF in foam cells. 相似文献
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目的:观察糖尿病大鼠心肌缺血再灌注时血管紧张素Ⅱ、胰岛素样生长因子1、醛固酮、细胞间黏附分子1和自由基代谢的变化及L-精氨酸对其的影响。方法:实验于2005-02/2006-06在江苏大学医学院机能学实验室完成。①实验分组:腹腔注射链脲佐菌素制作糖尿病大鼠模型,30只大鼠造模成功。按随机数字表法分为3组(n=10):心肌缺血再灌注组:开胸结扎冠脉,造成心肌缺血,60min后放松再灌注60min;L-精氨酸治疗组:于手术前4周灌胃L-精氨酸250mg/(kg·d),然后重复心肌缺血再灌注组操作;假手术组:完成操作后只穿线不结扎,观察2h作为对照。实验结束时心室取血6mL,摘取心脏,留取左心室心肌组织。②实验评估:检测大鼠血浆血管紧张素Ⅱ、醛固酮和血清胰岛素样生长因子1含量及心肌细胞间黏附分子1蛋白表达。检测大鼠血清、心肌组织超氧化物歧化酶、谷胱甘肽-过氧化物酶活性、丙二醛含量及心肌线粒体Na ,K -ATP酶、Mg2 -ATP酶、Ca2 -ATP酶活性。结果:30只大鼠全部进入结果分析。①与假手术组相比,心肌缺血再灌注组血浆血管紧张素Ⅱ、醛固酮含量明显升高(P<0.05~0.01),血清胰岛素样生长因子1含量降低(P<0.05);L-精氨酸治疗4周后血浆血管紧张素Ⅱ、醛固酮含量低于心肌缺血再灌注组(P<0.05~0.01),血清胰岛素样生长因子1含量高于心肌缺血再灌注组(P<0.05)。②与假手术组相比,心肌缺血再灌注组血清、心肌丙二醛含量明显升高(P<0.05),血清、心肌超氧化物歧化酶和谷胱甘肽-过氧化物酶活性明显降低(P<0.05 ̄0.01);用L-精氨酸治疗4周后血清、心肌丙二醛含量低于心肌缺血再灌注组(P<0.05 ̄0.01),血清、心肌超氧化物歧化酶和谷胱甘肽-过氧化物酶活性高于心肌缺血再灌注组(P<0.05~0.01)。③与假手术组相比,心肌缺血再灌注组心肌线粒体Na ,K -ATP酶、Mg2 -ATP酶、Ca2 -ATP酶活性明显降低(P<0.05),心肌细胞间黏附分子1蛋白表达明显升高(P<0.01);用L-精氨酸治疗4周后心肌线粒体Na ,K -ATP酶、Mg2 -ATP酶、Ca2 -ATP酶活性明显高于心肌缺血再灌注组(P<0.05),心肌细胞间黏附分子1蛋白表达低于心肌缺血再灌注组(P<0.05)。结论:血管紧张素Ⅱ、醛固酮和胰岛素样生长因子1可能共同参与了糖尿病心肌缺血再灌注的发生,细胞间黏附分子1蛋白表达与糖尿病心肌损伤关系密切。L-精氨酸通过减少细胞间黏附分子1蛋白表达,起心肌保护作用。糖尿病心肌缺血再灌注时存在自由基代谢异常,补充L-精氨酸后,可通过提高超氧化物歧化酶、谷胱甘肽-过氧化物酶和ATP酶活性,降低丙二醛水平,减轻自由基损伤,改善心肌组织功能。 相似文献
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