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21.
从自由基生物学角度评价鸡肉质量的实验研究 总被引:2,自引:0,他引:2
本文把外观健康和非健康的活鸡各20只分成两组,宰后测其肝、腿肌中超氧化物歧化酶(SOD)含量和脂质过氧化产物丙二醛(MDA)水平,发现两组中上述指标值差异显著(P<0.050 ;同时对两组实验鸡胴体在宰后4小时做了感官鉴别,也判断出其品质存在差异。提示体内SOD活性和MDA水平可以反映鸡肉质量,比感官鉴别更具敏感性,同时也可以反映宰前鸡的健康状况。 相似文献
22.
B. Leveugle B. A. Faucheux C. Bouras N. Nillesse G. Spik E. C. Hirsch Y. Agid P. R. Hof 《Acta neuropathologica》1996,91(6):566-572
Changes in the distribution of the iron-binding protein lactotransferrin have recently been described in the central nervous
system during a variety of neurodegenerative disorders. To investigate whether lactotransferrin is associated with the neuropathological
changes that characterize Parkinson’s disease, we analyzed the distribution of this protein in the mesencephalon of neurologically
normal individuals and patients affected with Parkinson’s disease using quantitative immunohistochemical methods. High levels
of lactotransferrin were observed in a large population of neurons in the substantia nigra of control cases. Lactotransferrin-positive
neurons were severely affected by the neurodegenerative process that occurs in Parkinson’s disease as indicated by a severe
decrease in the number of immunolabeled neurons in all of these cases. Quantitative analysis also demonstrated higher immunolabeling
levels of lactotransferrin in the surviving neurons in the substantia nigra and ventral tegmental area of Parkinson’s disease
cases compared to control cases. These results suggest that lactotransferrin may participate actively in the mechanism of
neuronal degeneration in Parkinson’s disease.
Received: 16 October 1995 / Revised, accepted: 1 December 1995 相似文献
23.
Periannan Kuppusamy Penghai Wang Michael Chzhan Jay L. Zweier 《Magnetic resonance in medicine》1997,37(4):479-483
The application of electron paramagnetic resonance imaging (EPRI) to obtain information from biological samples has been limited by the lack of ideal single line radical labels. The commonly used nitroxides exhibit multiple lines causing either hyperfine-based limitations in the maximum obtainable image resolution or hyperfine-based artifacts in the reconstructed image. The use of a novel single-line triarylmethyl paramagnetic label that enables marked enhancement in image quality and resolution is reported. This label exhibits a single line EPR spectrum that is sharp (linewidth ~60 mG in the absence of oxygen) and relatively stable in tissues. The potential of this label in enabling high resolution EPR imaging of biological samples was demonstrated in a series of phantoms and isolated biological organs such as the rat kidney. The images demonstrate that resolutions better than 100 μm could be obtained at L-band on samples of up to 20 mm in size. 相似文献
24.
In rabbit platelet rich plasma (PRP), 5-hydroxytraptamine (5-HT,0.03~3μmol/L) induced decrease in light transmission (DLT) dose-de pendently with centralization, as revealed by electron microscopy. However, 5-HT did not induced platelet aggregation and release reaction. 5-HT-induced DLT was inhibited by methysergide (0.3~30μmol/L), indomethacin (0.3~10μmol/L) and PGE_1 (0.01~0.3μmol/L) in a dose-dependent manner, but not EGTA(0.3~3mmol/L). Collagen(Coll), arachidonic acid (AA), adenosine diphosphate (ADP) and a stable thromboxane A2 analoge(STA_2) also induced DLT before aggregation by themselves, which was also inhibited by PGE_1, but not inhibited by EGTA except for Coll However,Coll-, AA-, STA_2-and ADP-induced DLT were reduced by pretreatment of PRP with 5-HT dose-depen-dently. The duration of DLT by Coll and AA were decreased from 151.4±5.93 sec and 15(?)38±0.60sec to 45.44±4.04 sec and 9.00±1.25 sec respectively ((?)±s(?) P<0.01), but not by ADP and STA_2, 3μmol/L of ADP-and 0.3μmol/L of STA_2-induced aggregation which was not accompanied with release reaction were enhanced by 5-HT pretreatment, but in those (Coil 5μg/ml, AA 100~200μmol/L and STA_2 1~3 μmol/L) with release reaction, the amount of adenosine triphosphate(ATP)were suppressed significantly (P<0.001) by 5-HT pretreatment without the effect on the magnitude of aggregation, The mobilization of cytosolic free calcium concentration ([Ca~(2+)]i) was observed after 5-HT treatment in single washed platelet, the results indicated that the basic level of [Ca~(2+)] i was 64.78±3.24nmol/L and this level was increased dose-dependently and significantly at 30 sec after administration of 5-HT and the time of peak value of [Ca~(2+)] i was at 90~100 sec.The similar time courses of suppression of ATP released during aggregation, in cases of Coll(5μg/ml), AA (200μmol/L) and STA_2(3μmol/L), by 5-HT were also found in the present experiment. 相似文献
25.
应用TBA荧光法检测了兔眼单纯晶体囊外摘除后和晶体囊外摘除并后房型人工晶体置入后房水内丙二醛含量,这二种手术后房水内丙二醛含量比正常眼显著增高(P<0.005,P<0.001)。结果提示前房内发生了脂质过氧化反应,这一发现有利于对眼内后房型人工晶体表面细胞反应及前膜形成进一步认识。 相似文献
26.
兔心肌挫伤心功能障碍与心肌细胞内Ca2+和线粒体ATP酶的变化 总被引:2,自引:1,他引:1
目的:探讨心肌细胞内游离钙([Ca^2 ]i)和心肌ATP酶变化在心肌挫伤(MC)后心功能障碍发生机制中的意义。方法:随机选取兔36只,分为6组:正常对照、伤后2、4、8、12、24h,每组6只。经右颈总动脉插管至左心室测左室压力。采用BIM-II型生物撞击机致成MC模型。在上述时相点测定左室压力,并测定心肌细胞内[Ca^2 ]i和心肌匀浆组织及线粒体ATP酶活力。结果:心脏收缩/舒张功能受到损害,心肌细胞内[Ca^2 ]i升高,心肌匀浆组织及线粒体ATP酶下降,相关分析表明心功能障碍与心肌细胞内[Ca^2 ]i含量升高呈明显负相关,与ATP酶活性降低呈明显正相关。结论:MC后心脏功能下降,心肌细胞内[Ca^2 ]i含量升高和ATP酶活性下降可能是其原因之一。 相似文献
27.
Neutrophil Oxygen Radical Production by Dialysis Membranes 总被引:1,自引:0,他引:1
The ability of different dialysis membranes to activate polymorphonuclearneutrophil oxygen radical production was investigated with chemiluminescence.All the six membranes, namely cuprophan, cellulose acetate,polycarbonate, polysulphone, polyacrilonitrile and polymethylmethacrylatewere able to interact with neutrophils and stimulate their oxygenradical production, the highest responses being seen with polyacrilonitrile,polymethylmethacrylate and polycarbonate. To analyse the roleof complement in this interaction, fresh plasma, heat inactivatedand zymosan-activated plasma were added: with fresh plasma oxygenradical production was stimulated on cuprophan, cellulose acetateand polysulphone, not modified on polycarbonate, and decreasedon polyacrilonitrile and polymethylmethacrylate. With heat-inactivatedplasma, the responses were decreased or abrogated on all themembranes except polycarbonate and polymethylmethacrylate, whereaswith zymosanactivated plasma similar responses to fresh plasmawere observed. In addition, when plasma was used to precoatthe membrane, cuprophan, cellulose acetate and polysulphonedisclosed an enhanced neutrophil oxidative burst, while precoatedpolyacrilonitrile and polymethylmethacrylate were less stimulatorythan uncoated membranes. In contrast the precoating of polycarbonatedid not modify oxygen radical production. These data suggestthat neutrophil activation occurs by direct membrane neutrophilinteraction. Plasmatic factors modulate this interaction butcomplement seems involved on cellulosic and polysulphone membranesonly. Therefore, it appears that oxygen radicals produced fromcontact of neutrophils with the dialysis membrane might playan initial and/or additional role in the events occurring atthe initiation of haemodialysis. 相似文献
28.
Minbo Lan Nelson Beghein Nicolas Charlier Bernard Gallez 《Magnetic resonance in medicine》2004,51(6):1272-1278
New electron paramagnetic resonance (EPR) oximetry probes were identified in the class of carbon black materials. These compounds exhibit very high oxygen sensitivity and favorable EPR characteristics for biological applications. At low pO(2), the linewidth is particularly sensitive to changes in oxygen tension (sensitivity of 750 mG/mmHg). The application of the probes for oximetry was demonstrated in vivo: the pO(2) was measured in muscle in which the blood flow was temporarily restricted as well as in tumor-bearing mice during a carbogen breathing challenge. The responsiveness to pO(2) was stable in muscle for at least 3 months. No toxicity was observed using these materials in cellular experiments and in histological studies performed 2, 7, and 28 days after implantation. In view of their EPR characteristics (high sensitivity) as well as the well-characterized production procedure that make them available on a large scale, these probes can be considered as very promising tools for future developments in EPR oximetry. 相似文献
29.
30.
直接用木瓜蛋白酶水解软骨,三氯醋酸除蛋白质,乙醇沉淀干燥得硫酸软骨素粗多糖,经DEAE-Sepharose fast flow离子交换层析分离纯化,高效凝胶渗透色谱和琼脂糖凝胶电泳测定其相对分子质量和纯度,比较硫酸软骨素粗品和纯品的体外自由基清除活性。结果显示硫酸软骨素粗品和纯品提取率分别为31.56±0.46%和19.79±0.78%,后者相对相对分子质量为75 174,粗品的DPPH.和.OH清除活性最强,随着产品纯度的提高,活性降低,而对于O2-.清除活性结果则相反。 相似文献