Characterization of angiotensin II binding sites on neuroblastoma × glioma hybrid cells

Mouse neuroblastoma X rat glioma hybrid cells, NG108-15, have recently been shown to contain immunoreactive angiotensin II (AII). In the present study, we have examined this hybrid cell line for the presence of specific AII binding sites using [125I] AII. Specific AII binding was saturable and reversible. Scatchard analysis revealed a linear plot with an affinity constant (Kd) of 0.323 nM and a binding capacity (Bmax) of 7.13 fmol/mg protein. Kinetic studies demonstrated an association rate constant (K+1) of 3.55 X 10(6) M(-1) sec-1 and a dissociation rate constant (K-1) of 4.18 X 10(-4) sec-1. Displacement curves, using concentrations of 10(-11) M to 10(-4) M of unlabeled AII, revealed high and low affinity components of the AII binding site with IC50's of 0.46 nM and 1.75 microM respectively. The AII antagonist, saralasin, had approximately equal potency with unlabeled AII at the high affinity site. Furthermore, structurally related and unrelated peptides had no significant inhibitory effect on AII binding. This study demonstrates that specific AII binding sites are present on NG108-15 cells, and that these binding sites are similar in kinetic character to the AII receptor that has been previously identified in membranes from mammalian brain. It is concluded that the NG108-15 hybrid cells may provide a useful continuous cell line model for investigating both the biochemical and molecular properties of the AII binding site.     

Influence of repeated deprivation upon starvation-induced hypovolemia and plasma aldosterone concentration in rats

Rats exposed to repeated periods of food deprivation during development revealed significant inhibition of starvation-induced hypovolemia as adults. Same age littermates food deprived once as adults indicated severe hypovolemia. Plasma aldosterone (but not angiotensin II) was significantly elevated in the repeatedly fasted group as compared with the control and the singly deprived groups. It is concluded that the repeated application of food deprivation during development results in physiological compensation in the form of increased aldosterone release if starvation is encountered in adulthood. These increments in plasma aldosterone promote greater sodium retention thus lessening the compromising of blood volume necessary to maintain normal plasma osmolality given the lack of dietary sodium.     

The diagnosis of renovascular hypertension: the role of captopril renal scintigraphy and related issues

This article reviews the screening and diagnostic tests used in the detection of significant renal artery stenosis and renovascular hypertension. After addressing the pathophysiological considerations necessary for correct diagnostic test interpretation, this review critically surveys the recent advances in, and the limitations of, relevant investigational procedures and in particular focusses on the efficacy and issues of Angotensin-converting enzyme inhibitor renal scintigraphy.This review is based on the themes developed in a lecture given by the author at the European Association of Nuclear Medicine Congress in Lisbon on 25 August 1992     

CEP-11004, an inhibitor of the SAPK/JNK pathway, reduces TNF-alpha release from lipopolysaccharide-treated cells and mice

Oxidative stress and low-grade inflammation are hallmarks of diabetes mellitus. We explored protective, blood pressure-independent effects of the angiotensin II type 1 (AT₁) receptor antagonist candesartan and the selective β₁-adrenoceptor antagonist metoprolol. Diabetes mellitus was induced in 8-week-old Sprague–Dawley rats after injection of streptozotocin. Diabetic rats were randomized to treatment with candesartan or metoprolol in sub-antihypertensive doses or to placebo treatment. In the quadriceps, musculature markers of oxidative stress and inflammation were determined. Function of the inherent vascular bed was measured in vivo in the autoperfused hindlimb. Increases in NAD(P)H activity, expression of its cytosolic subunit p22^phox and of endothelial NO synthase e(NOS) displayed enhanced oxidative stress. Upregulated intercellular (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 and of inducible NOS (iNOS) revealed inflammatory processes. Diabetes was associated with severe impairment of endothelium-dependent and -independent vasodilatation. Candesartan, but not metoprolol, reduced NAD(P)H activity, attenuated diabetes-induced over-expression of p22^phox and eNOS mRNA as well as ICAM-1, VCAM-1, iNOS and eNOS immunoreactivity and led to a substantial improvement of endothelium-dependent vasodilatation (+ 46.3% vs. placebo treatment; P < 0.05). Angiotensin AT₁ receptor antagonism, but not β₁-adrenoceptor antagonism, ameliorates diabetes-generated oxidative stress, indicating a pivotal role of the renin–angiotensin system in the development of diabetic complications.     

AGREEⅡ评价9个儿童青少年维生素D临床实践指南及推荐意见共识和差异

目的 使用指南研究与评价工具Ⅱ（AGREEⅡ）评价儿童青少年维生素D（VD）临床实践指南（VD指南）,反映目前儿童青少年补充VD的基本共识和存在的争议.方法 制定VD指南的纳入标准和检索策略,检索PubMed、Web of Science、中国期刊全文数据库、万方数据库、维普中文科技期刊数据库、美国国立指南文库（NGC）、指南国际网络（G-I-N）等相关指南数据库,按纳入标准纳入有关儿童青少年VD指南,提取和描述VD指南AGREEⅡ评价信息,使用AGREEⅡ评价纳入指南质量,使用组内相关系数（ICC）进行评价员间一致性检验.分析比较不同VD指南推荐内容的共识和差异.结果 共纳入9篇VD指南,分别来自美国、中国、加拿大、法国、波兰和澳大利亚/新西兰.发表年度从2006至2012年.3篇为循证指南,其中2篇采用GRADE证据分级系统,1篇采用AHRQ证据分级系统;其余6篇为非循证指南.①指南质量经AGREEⅡ评分显示：6大领域的评分中,范围和目的 、清晰性和应用性的总体平均得分均〉50%,指南制定的参与人员、制定的严谨性和编辑的独立性有待加强（平均得分分别为48%、42%和28%）;循证指南在指南的参与人员、制定的严谨性、编辑的独立性方面优于非循证指南.②总体归纳不同VD指南之间在推荐内容上有5个方面的主要差异.VD预防建议：各指南基本认同的是0～1岁婴儿400 IU·d-1的VD缺乏预防量是安全的;VD治疗建议：美国（ES）指南推荐2 000 IU·d-1（1～18岁）,维持6周;阳光照射：美国和澳大利亚/新西兰的指南持不同推荐意见;VD2或VD3：不同指南推荐意见不同;25羟维生素D（25OHD）水平：各指南基本认同25OHD水平〈30 nmol·L-1时,佝偻病的患病率增加;孕妇及哺乳期妇女：各指南推荐这一人群要注意及时补充VD,或维持适宜的25OHD水平.结论 ①纳入VD指南整体质量仍有待提高.循证指南质量在指南的参与人员、制定的严谨性、编辑独立性方面优于非循证指南.②纳入VD指南推荐内容虽有一定的差异,但对于0～18岁人群400 IU·d-1的VD缺乏预防量被认为是安全的剂量.③中国VD指南推荐内容参考了国外高质量的指南,改编和制定国内高质量的指南迫在眉睫.     

臂丛根性撕脱伤激活脊髓表达磷酸化CaMKⅡ的时程及定位研究

目的研究大鼠臂丛根性撕脱伤后磷酸化CaMKⅡ的时间和空间定位。方法将SD大鼠(6～8周龄)在手术显微镜下做臂丛根性撕脱伤手术后,应用Western blot方法测定相应脊髓节段(C7、C8)磷酸化CaMKⅡ在1、2、3 d时间点及正常大鼠的表达水平。同时应用免疫荧光染色方法检测目标蛋白在1 d时间点大鼠脊髓节段的表达水平及空间定位。结果正常大鼠脊髓相应节段检测不到磷酸化CaMKⅡ,在臂丛根性撕脱伤后1～2 d对应脊髓节段的磷酸化CaMKⅡ表达明显升高,撕脱伤后3d明显下降并接近正常水平;免疫荧光结果显示:臂丛根性撕脱伤后1 d,损伤侧脊髓前角运动神经元和中间神经元明显表达磷酸化CaMKⅡ,对侧脊髓前角运动神经元和中间神经元也有表达,但强度较撕脱侧明显减弱。结论臂丛根性撕脱伤诱导磷酸化CaMKⅡ在损伤节段1 d时高表达,然而在3 d时逐步下降到正常水平。     

血管组织工程种子细胞的建立及意义

目的：利用人Nanog基因转染血管组织工程的种子细胞（血管内皮细胞ECV304）,提高其增殖能力,以在较短时间内获得大量种子细胞,从而为克服血管组织工程种子细胞来源的匮乏及组织工程血管的快速构建提供新途径。方法：制备含有人Nanog基因的复制缺陷型重组腺相关病毒血清2型病毒颗粒rAAV2-hNanog,用rAAV2-hNanog转染ECV304细胞,然后采用RT-PCR检测hNanog基因在转染的ECV304细胞中的表达,再用MTT、免疫荧光及激光共聚焦技术检测hNanog基因对血管内皮细胞ECV304生长的影响。结果：（1）rAAV2-hNanog转染ECV304细胞后,RT-PCR检测表明hNanog基因能在血管内皮细胞ECV304中稳定表达;同时,血管内皮细胞在转染后的增殖能力也显著增强（P〈0.05）。光镜下观察发现,转染的血管内皮细胞的形态无明显改变。结论：转染hNanog基因后,血管内皮细胞的形态无显著变化,但其增殖能力明显增强。利用hNanog基因提高血管内皮细胞的增殖能力,能够克服血管组织工程种子细胞来源不足的瓶颈,为组织工程血管的快速构建及应用提供一种新的方法。     

血管紧张素Ⅱ对创伤愈合中成纤维细胞增殖影响的研究

目的：探讨血管紧张素Ⅱ（angiotensinⅡ,AngⅡ）对创面愈合中成纤维细胞增殖的影响及不同浓度AngⅡ对创面作用的差异。方法：采用不同浓度AngⅡ作用于小鼠新鲜创面,应用流式细胞仪检测相同面积创面中S（DNA合成期）期成纤维细胞所占的比例。结果：与对照组相比,AngⅡ可有效促进创面中成纤维细胞的增殖,从而促进创面肉芽组织生长,使创面愈合加快。结论：AngⅡ可促使局部创面成纤维细胞增殖,从而加快创面愈合,且呈浓度依赖性。     

血管紧张素Ⅱ-1型受体基因多态性与原发性高血压合并脑梗死的关系

目的:探讨血管紧张素Ⅱ-1型受体基因多态性与原发性高血压合并脑梗死之间的关系。方法:选取2008年9月～2012年4月收治的高血压合并脑梗死患者72例,将其作为观察Ⅱ组,另选取同期我院收治的原发性高血压68例患者作为观察Ⅰ组,随机选取来我院进行体检的健康者121例作为对照组。3组参与者均采用聚合酶链反应技术检测血管紧张素Ⅱ-I型受体基因多态性,并进行比较分析。结果:3组参与者的基因型频率和等位基因,两两比较,均有显著性差异(P<0.05或0.01)。结论:血管紧张素Ⅱ-1型受体基因AA和AC基因型可能是原发性高血压的重要遗传因素,但A等位基因与原发性高血压患者不存在相关性,而C等位基因可能直接作用于脑梗死。     

改良双轨道装置GMD推磨牙远移的临床应用

目的：探讨一种改良推磨牙远移装置的临床效果。方法：选择AngleⅡ^错[牙合],上颌轻度前突或牙列拥挤,下颌正常或轻度后缩病例,第一期应用Nance托NiTi方丝多曲弓推磨牙远移矫治。第二期使用直丝弓矫治器矫治,治疗前后进行X线头影测量分析。结果：应用该矫治法解决了非拔牙矫治中间隙预备问题,为磨牙中性殆的建立创造了条件。结论：Nance托联合多曲NiTi方弓推磨牙远移是一种方法简便、安全可靠,有效的非患者依从性矫治方法。