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41.
不同胎龄母婴间血清前白蛋白与锌、钙、镁水平测定 总被引:1,自引:0,他引:1
王西阁 《中国优生与遗传杂志》2003,11(4):70-71
目的 为检测不同孕周母婴间血清前白蛋白 (PA)与锌、钙、镁的水平及它们之间的关系。方法 采用免疫单项扩散法及原子吸收分光光度计火焰法检测了 4 0对早产与 14 8对健康足月母婴血清前白蛋白及锌钙镁的含量。结果 4 0对早产与 14 8对健康足月母亲血清PA均显著高于新生儿脐血PA(P <0 0 0 1) ,血清锌显著低于新生儿 (P <0 0 0 1) ,血清钙早产母亲显著高于早产儿 ,足月母亲则显著低于足月儿。血清镁早产及足月母亲均略低于新生儿 (P >0 0 5 )。各孕周母婴间PA、镁无相关性 ,锌、钙呈正相关。 (相关系数分别为早产 0 39、0 33,足月 0 4 1、0 35 ,(P <0 0 1) ,早产儿脐血血清PA显著低于足月儿 (P <0 0 0 1) ,脐血血清锌低于足月儿 (P <0 0 1) ,脐血血清钙低于足月儿 (P >0 0 5 )。各孕周新生儿脐血PA与自身锌、钙、镁相关分析无相关性。结论 检测各孕周母婴PA、锌、钙、镁的含量 ,可以综合评价早产儿、足月儿的营养状况。 相似文献
42.
The effect of extracellular magnesium concentration (Mgo) on the upstroke of the action potential was studied in guinea pig ventricular muscle under various K+ concentrations (2.7–19mM). Increased Mgo shifted the steady state inactivation curve of the fast Na channel in the depolarizing direction and this effect was concentration-dependent (0–20mM). Such an effect could explain the Mg-induced increase in maximum rate of rise of the action potential which Späh and Fleckenstein (1979) proposed to be due to a Mg channel. 相似文献
43.
Mollie E. Holman John P. Weinrich 《Pflügers Archiv : European journal of physiology》1975,360(2):109-119
Summary The membrane potential of smooth muscle cells in the circular layer of the guinea pig ileum was recorded using intracellular electrodes. Transmural stimulation, in the presence of atropine, caused a transient hyperpolarization, an inhibitory junction potential (IJP). IJP's are thought to result from the action of transmitter released from intramural inhibitory nerves. It has been reported that, in the guinea pig jejunum, the amplitude of the IJP resulting from field stimulation is not altered by changes in the calcium and magnesium ion concentration in the bathing solution. Experiments reported here have shown that the IJP amplitude decreased markedly on reducing the calcium ion concentration and or increasing the magnesium ion concentration. Indirect evidence is presented suggesting that the decrease in amplitude of the IJP is due to a decrease in the amount of transmitter released. 相似文献
44.
Alloys based on Ni–Ti intermetallics generally exhibit special shape memory and pseudoelastic properties, which make them desirable for use in the dental field as orthodontic wires. The possibility of nickel release from these materials is of high concern, because the allergenicity of this element. The aim of this study was to test pseudoelastic Ni–Ti wires in simulated physiological conditions, investigating the combined effect of strain and fluoridated media: the wires were examined both under strained (5% tensile strain) and unstrained conditions, in fluoridated artificial saliva at 37 °C. Real time electrochemical nickel release testing was performed using a novel application of a radiotracer based method, thin layer activation (TLA). TLA was validated, in unstrained conditions, against adsorptive stripping voltammetry methodology. Control tests were also performed in non-fluoridated artificial saliva. From our research it transpired that the corrosion behaviour of Ni–Ti alloy is highly affected by the fluoride content, showing a release of 4.79 ± 0.10 μg/cm2/day, but, differently from other biomaterials, it does not seem to be affected by elastic tensile strain. The application of the TLA method in the biomedical field appears a suitable technique to monitor in real time the corrosion behaviour of biomedical devices. 相似文献
45.
镍钛形状记忆合金血管内支架组织相容性实验研究 总被引:16,自引:1,他引:16
将锥形记忆合金支架分别植入6只猪右侧髂动脉。用以研究镍钛形状记忆合金血管内支架生物相容性,支架植入前入植入后8个月,观测动物血常规,肝肾功能以及毛发中镍钛元素含量,均无明显变化(P〉0.05),支架植入后8个月处死动物,全身重要脏器(肝、脾、肾、肺、心、脑等)病理学检查结构正常,无淋巴细胞和单核细胞浸润,支架植入部位上游血管壁内膜光滑,内皮细胞结构正常,内弹力板完整,支架植入段为完整肉芽组织阻塞, 相似文献
46.
Judy Y. Su 《Pflügers Archiv : European journal of physiology》1992,421(1):1-6
Ryanodine, a blocker for Ca2+-release channels of the sarcoplasmic reticulum (SR Ca2+-release channels), induces depression of myocardial contraction in isolated intact muscle, which is consistent with depression of the caffeine-induced tension transient in skinned muscle fibers. In isolated SR, ryanodine binds to a specific receptor with high affinity, and this binding is enhanced by caffeine and increasing Ca2+ and decreased by increasing Mg2+. The aim of this study was to test the hypothesis that depression of myocardial contraction is mediated by changes in ryanodine-receptor binding properties. Accordingly, factors (caffeine, Ca2+, and Mg2+) affecting ryanodine-receptor binding properties in the isolated SR membrane were studied in skinned myocardial fibers from adult rabbits. The depression of the caffeine-induced tension transient by ryanodine (ryanodine depression) influenced by these three factors was measured. In a dose-dependent manner, increasing caffeine or Ca2+ concentrations enhanced the ryanodine depression. The concentrations for 50% ryanodine depression (IC50) approximated 7mM for caffeine, and pCa 5.25 for Ca2+. When 1 M ryanodine and 25 mM caffeine were combined, ryanodine depression was independent of Ca2+ at low Ca2+ concentrations (20%–30% at pCa>8 and 7.5) and was a direct function of Ca2+ at higher concentrations (pCa 7.5–6.0 with IC50 approx. pCa 6.75). In contrast, increasing Mg2+ reduced the ryanodine depression with IC50 approximately equal to pMg 3.3. In conclusion, the caffeineor Ca2+-enhanced, and Mg2+-reduced ryanodine depression observed in this study is consistent with known ryanodinereceptor binding properties. 相似文献
47.
大鼠内毒素休克肝线粒体Ca^2+,Mg^2+含量变化与线粒体损伤 总被引:5,自引:1,他引:5
本文在大鼠内毒素休克模型上,观察了肝线粒体结构和功能与Ca^2+,Mg^2+含量变化的关系。结果发现:休克动物肝组织和线粒体的Ca^2+浓度升高,Mg^2+浓度下降与正常对照组相比有非常显著性差异;用图像分析仪定量分析显示线粒体结构明显受损,线粒体标志酶之一-琥珀酸脱氢酶(SDH)活性明显下降,本文认为组织和线粒体内Mg^2+/Ca^2+比值下降是休克细胞不可逆损伤重要因素之一。 相似文献
48.
目的:探讨细胞内镁含量对C57BL/6哮喘小鼠肺组织β2受体mRNA表达的影响。方法:健康4-6周龄清洁级雌性C57BL/6小鼠96只,体重(12±2)g,随机数字表法分为A、B、C、D 4组,每组各24只。应用鸡卵蛋白(OVA)建立哮喘小鼠模型。A、B组予低镁饲料喂食,C、D组予正常镁饲料喂食。B、D组腹腔内注射沙丁胺醇诱导β2受体低调节,A、C组腹腔内注射生理盐水作对照。第1 d、21 d、34 d各组分别随机抽取8只检测血浆Mg2+、红细胞内Mg2+、肺组织β2受体mRNA及蛋白表达。 结果:1 d血浆Mg2+、红细胞内Mg2+、肺组织β2AR mRNA及蛋白表达各组间差异无显著(均P>0.05)。21 d、34 d C组血浆Mg2+、红细胞内Mg2+、肺组织β2AR mRNA及蛋白表达均显著高于A组[21 d:(0.84±0.09)mmol/L vs (0.57±0.10)mmol/L、(2.39±0.14)mmol/L vs (2.11±0.08)mmol/L、(0.75±0.09)mmol/L vs (0.59±0.06)pmol/g、(88.50±8.50)pmol/g vs (60.10±7.70)pmol/g,均P<0.05;34 d:(0.67±0.10)mmol/L vs (0.51±0.09)mmol/L、(2.17±0.08)mmol/L vs (2.05±0.09)mmol/L、(0.61±0.05)pmol/g vs (0.53±0.06)pmol/g、(76.60±7.10)pmol/g vs (58.00±7.60)pmol/g,均P<0.05];21 d、34 d D组血浆Mg2+、红细胞内Mg2+、肺组织β2AR mRNA及蛋白表达亦显著高于B组[21 d:(0.95±0.33)mmol/L vs (0.46±0.09)mmol/L、(2.32±0.18)mmol/L vs (1.87±0.14)mmol/L、(0.73±0.10)pmol/g vs (0.43±0.07)pmol/g、(96.90±8.00)pmol/g vs (47.90±4.90)pmol/g,均P<0.05;34 d:(0.71±0.10)mmol/L vs (0.31±0.08)mmol/L、(1.66±0.13)mmol/L vs (1.45±0.16)mmol/L、(0.40±0.07)pmol/g vs (0.33±0.05)pmol/g、(61.50±3.20)pmol/g vs (35.30±7.10)pmol/g,均P<0.05]。结论:细胞内镁缺乏的C57BL/6哮喘小鼠肺组织β2受体表达减少,在激动剂作用下更易发生β2受体低调节。 相似文献
49.
Fatemeh Jahanian Iraj Goli Khatir Hamed Amini Ahidashti Sepideh Amirifard 《Ethiopian journal of health sciences》2021,31(2):267
BackgroundAcute exacerbations of chronic obstructive pulmonary disease (AECOPD) are serious complications that often require immediate intervention in an emergency department (ED). The aim of this study was to investigate the effect of intravenous magnesium sulphate as an adjuvant in the treatment of AECOPD in the ED.MethodsIn a double-blind, randomized clinical trial, a total of 60 patients with AECOPD presenting to the ED of Imam Khomeini Hospital in Sari, Iran, were included. The study was conducted between September 2016 and February 2018. Eligible patients were randomly allocated into two groups of intervention and control. Patients in the intervention and control groups received intravenous infusion of magnesium sulfate (2 gr) or normal saline over 30 minutes, respectively. For all patients, Borgdyspnea score, forced expiratory volume in one second (FEV1) result and clinical variables of interest were evaluated before the beginning of the intervention, and also 45 minutes and 6 hours after the commencement of intervention.ResultsRegardless of time of evaluation, pulse rate (PR), respiratory rate (RR) and Borg score in intervention group was lower than control group. Also, FEV1 and SPO2 were greater in intervention group compared to control group. However, these differences were not statistically significant (between-subject differences or group effect) (p<0.001). The trends of FEV1, SPO2, PR, RR and Borg score were similar between two groups of study (no interaction effect; P>0.05).ConclusionAccording to the results of this study, it seems that using intravenous magnesium sulfate has no significant effect on SPO2, FEV1, RR, and PR of patients with AECOPD who presented to ED. 相似文献
50.