共查询到19条相似文献，搜索用时 140 毫秒
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类胰蛋白酶是一种由肥大细胞（Mast cell,MC）特异性贮存和分泌的蛋白酶,其类型、数量和特性随肥大细胞亚型、组织和种属起源的不同而存在差异。MC可表达α、β和γ三种类胰蛋白酶,其中β类胰蛋白酶含量最高,是MC脱颗粒时主要释放的酶。类胰蛋白酶可以通过不同的机制促使炎症发生,破坏基底膜的完整性以及促进组织的构型重塑;也可以通过降解细胞因子来调节机体的免疫应答;还可以通过弱化引起炎症的变应原以及神经肽来抑制炎症的发生。因此,像肥大细胞一样,类胰蛋白酶在炎症的发生和宿主防御过程中也起到了多重作用。 相似文献
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《黑龙江科技信息》2020,(9)
颗粒酶A(Granzyme A,Gzm A)是一类定位于活化淋巴细胞和自然杀伤(NK)细胞胞质的丝氨酸蛋白酶,是细胞毒性颗粒中表达丰度最高的蛋白酶之一。Gzm A能够特异性靶向人体很多重要的蛋白,如:组蛋白,维持核膜的核纤层蛋白和几种关键的DNA损伤修复蛋白(Ku70,PARP-1);激活白细胞介素-1,具有促炎活性。Gzm A激活了一种新的程序性细胞死亡途径,该途径始于线粒体,产生活性氧(ROS),导致单链DNA损伤,参与杀死敏感的靶细胞。此外,还可作为免疫检查点以及生物标志物。本文主要就Gzm A晶体结构、特异性结合蛋白种类以及在肿瘤免疫中发挥的重要功能进行综述。 相似文献
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人工湿地基质中土壤酶空间分布及其与水质净化效果之间的相关性 总被引：14，自引：0，他引：14
人工湿地已被广泛用于处理各种类型的废水．研究了人工湿地基质中磷酸酶、脲酶和蛋白酶活性的空间分布规律及与污水净化效果之间的关系．磷酸酶和脲酶的活性随基质深度的增加而降低，蛋白酶活性在基质上层最高，下层次之，中层最低；湿地上池基质磷酸酶、脲酶和蛋白酶活性大于下池．磷酸酶活性与污水总磷、CODcr，BOD5除率正相关；脲酶与总氮的去除率正相关；蛋白酶与总氮、总磷、CODcr,BOD5去除率没有相关性．该研究为利用酶活性作为评价净化效果的指标提供了理论依据。 相似文献
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猪血浆中凝血酶、免疫球蛋白等功能蛋白的联合提取 总被引：1，自引：0，他引：1
实验对猪血浆中白蛋白、免疫球蛋白、纤维蛋白原及凝血酶等功能蛋白进行了联合提取。通过对各步骤中蛋白的检测确立了一套有效的联合提取方法：将柠檬酸钠抗凝的血浆经冻融处理,离心得到纤维蛋白原沉淀，上清通过吸附法提取凝血酶后再经盐析法分离提取白蛋白及免疫球蛋白。1L血浆可同时提得白蛋白31.41g、免疫球蛋白13.86g、凝血酶粗品0.22g（比活力为38.5U/mg）、纤维蛋白原为2.67g。 相似文献
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目的:采用跑台训练方式,建立大鼠运动模型,运用免疫组织化学SABC法研究不同负荷运动对大鼠海马CA1区Bax、Bcl-2表达的影响。方法:将大鼠分为对照组、中等强度运动组和大强度运动组,对大鼠进行为期5周的跑台训练,用免疫组化结合图像分析技术观察海马神经元中Bax、Bcl-2的免疫反应活性。结果:中等强度运动后,大鼠海马CA1区神经元Bcl-2蛋白的表达显著上升,Bax蛋白略微增加,Bax/Bcl-2显著下降。大强度运动后,大鼠海马CA1区神经元中Bcl-2蛋白的表达略微增加,Bax蛋白的表达显著增加,Bax/Bcl-2显著增高。结论:中等强度运动可促使Bcl-2蛋白的表达,使Bax/Bcl-2显著降低,抑制细胞凋亡;而大强度运动促进Bax蛋白的表达,使Bax/Bcl-2比例显著增加,促进细胞凋亡。 相似文献
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BackgroundIt has been a very common practice to use probiotics or their metabolites as alternative antimicrobial strategies for the treatment and prevention of infections as rampant and indiscriminate use of antibiotics causes the development of antibiotic-resistant pathogens. The objective of this study was to select a potential antimicrobial probiotic strain of Escherichia coli from the human gastrointestinal tract and investigate the production of diketopiperazines that contribute to the antimicrobial activity.ResultsE. coli GutM4 was isolated from the feces of a healthy adult. E. coli GutM4 showed significant antagonistic activity against 10 indicator pathogens, and this activity was no less than that of the reference strain E. coli Nissle 1917 against eight of the indicator pathogens. Moreover, E. coli GutM4 produced antagonistic substances containing trypsin-targeted peptide bonds because the inhibitory effects of E. coli GutM4 supernatant significantly decreased upon treatment with trypsin. Consistent with the antagonistic activity and peptide compounds of E. coli GutM4, 14 2,5-diketopiperazines were isolated from the fermented broth of E. coli GutM4, including 12 cyclo(Pro-Phe), 3 cyclo(Pro-Tyr), and 5 cyclo(4-hydroxyl-Pro-Leu), which are reported to have antipathogenic activity.ConclusionE. coli GutM4 produces 2,5-diketopiperazines that are partly involved in antagonistic action against human pathogens in vitro. 相似文献
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In a perspective study, the ascitic fluid and serum concentration of total cholesterol, total proteins and albumin in a group
of 45 patients was studied. Patients with nonmalignant or cirrhotic ascites were compared with patients having malignancy
related ascites and it was proved that the ascitic fluid cholesterol and the serum ascites albumin gradient helped to differentiate
cirrhotic from malignant ascites. These two parameters showed a remarkable relationship to the presence/absence of malignancy.
Non malignant ascites patients had ascitic fluid cholesterol values of 19.41±8.33 mg/dl, as against the malignancy related
ascites patients, who showed levels of 95.87±1.24 mg/dl. Similarly, the serum-ascites albumin gradient levels were 2.89±0.65
in non malignant ascites patients, while the malignancy related ascites cases had 0.86±0.50. The discrimination values for
cholesterol were taken as 45 mg/dl while that for serum ascites gradient was taken as 1.1. Levels of serum cholesterol, total
protein and albumin were not significantly altered. 相似文献
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采用连续二倍梯度琼脂稀释法研究龙脷叶水提物和的50%、70%、95%乙醇提取物的抑菌活性,并对抑菌作用强的提取物以石油醚、乙酸乙酯、正丁醇依次萃取,测定不同极性部位的最低抑菌浓度(MIC)。结果表明,龙脷叶50%乙醇提取物的正丁醇部位对六种试验菌株明显抑制:对金黄色葡萄球菌(Staphylococcus aureus)、金黄色葡萄球菌耐药株(Methicillin resistant Staphylococcus aureus)和大肠杆菌(Escherichia coli)的MIC为15.60m g·mL-1;对铜绿假单胞菌(Pseudomonas aeruginosa)、伤寒沙门氏菌(Salmonella typhi.)和乙型副伤寒沙门氏菌(Bacillus paratyphosus B)的MIC为7.81m g·mL-1。可为进一步研究龙脷叶抑菌活性成分提供依据。 相似文献
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The purpose of this study was to investigate the Bcl2, P53 and apoptosis changes against skin cancer in experimental animals. Skin cancer is the most common form of human cancer. It is estimated that over 1 million new cases occur annually. The annual rates of all forms of skin cancer are increasing each year, representing a growing public concern. It has also been estimated that nearly half of all Americans who live to age 65 are likely to develop skin cancer at least once. Skin cancer was induced in rats by Di Methyl Benz (a) Anthracene at the dosage of DMBA (5 µg) per animal, three times a week for 28 weeks after conformation of skin cancer treated with Paclitaxel and Di allyl sulfide for 30 days. The levels of Bcl2 gene expression were significantly decreased and P53gene expression were markedly increased in Paclitaxel and Di allyl sulfide treated animals when compared with cancer bearing animals. The treatment with combination of Paclitaxel and Di allyl sulfide effectively reduced Bcl2 protein expression and also increased P53gene expression. Moreover, the levels of Bcl2 and P53 a good indicators of restoring the skin architecture, were also reversed in skin damage subjects after treatment with the herbal compounds preparation. So, from the obtained results it is concluded that a combination of Paclitaxel and Di allyl sulfide is capable of restoring the skin architecture and can also increase the apoptosis activities in skin cancer rats. 相似文献
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血镁与2型糖尿病视网膜病变的相关研究 总被引：1，自引：0，他引：1
为了探讨血镁在糖尿病视网膜病变发生中的作用及糖尿病视网膜病变的相关危险因素，测定了30例正常对照组，30例糖尿病无视网膜病变级（NDR组），30例糖尿病合并视网膜病变组（DR组）病人血清镁浓度，并对糖尿病病人行空腹血糖、糖化血红蛋白（HbAlc）、尿微量白蛋白排泄量的测定，记录病程，行眼底检查，结果发现，与正常相比较，血镁降低在NDR组P＜0．05，DR组P＜0．01。NDR组与DR组比较血镁降低亦有显著性意义（P＜0．01），且两组比较病程、空腹血糖、糖化血红蛋白和尿白蛋白排泄是均有显著性差异（P＜0．01）。作者认为糖尿病病人有缺镁的倾向，且糖尿病视网膜病变者的血镁比糖尿病无视网膜病变的患者更低，低镁与病程、空腹血糖、糖化血红蛋白、尿白蛋白排量一样，是糖尿病视网膜病变的危险因素。 相似文献
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缺血、缺氧可引起大鼠离休灌流肝脏的损伤,这种损伤涉及反应性氧族对肝脏的氧化破坏.白蛋白具有很强的抗氧化作用.在本研究中,0.1％、1％、2％和5％的牛血清白蛋白可保护大鼠离体灌流肝脏由缺血、缺氧引起的损伤,而且不合流基和脂肪酸的牛血清白蛋白制剂及人白蛋白也有同样的保护作用.该保护作用不是通过白蛋白结构上的巯基,也不是通过白蛋白结合的脂肪酸来实现的.很可能是通过白蛋白与催化产生羟自由基或类羟自由基的跃迁金属离子及与反应性氧族的非特异性结合而实现的。 相似文献
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R. Katyal S V Rana S. Ojha V. Singh R. P. Aggarwal 《Indian journal of clinical biochemistry : IJCB》2005,20(1):118-122
The aim of the study was to evaluate the influence of rotavirus (RV) and soyabean trypsin inhibitor (TI) on lipid composition
and uptake of glucose and glycine in rotavirus (RV) infected malnourished (PEM) infant mice. Malnutrition was achieved in
animals by doubling the litter size. Cholesterol (Ch) and phospholipd (PL) contents, uptake levels of glucose and glycine
were determined in jejunum and ileum portion of small intestine. Increase in Ch/PL ratios was observed in PEM+RV group. The
levels became comparable in PEM+RV+TI as compared to PEM. Uptake levels of glucose and glycine increased in PEM animals. With
rotavirus (PEM+RV+TI group), the levels decreased which became comparable to PEM. Changes in uptake and lipid composition
with rotavirus and trypsin inhibitor may be responsible for altering membrane fluidity and organization during rotavirus diarrhea.
The results establish the importance of trypsin inhibitor during oral infection with rotavirus. 相似文献