Sequence of human tissue inhibitor of metalloproteinases and its identity to erythroid-potentiating activity

Collagen fibres form the stable architecture of connective tissues and their breakdown is a key irreversible step in many pathological conditions. The destruction of collagen is usually initiated by proteinases, the best known of which is the metalloproteinase collagenase (EC 3.4.24). Collagenase and related metalloproteinases are regulated at the level of their synthesis and secretion, through the action of specific stimuli such as hormones and cytokines, and also at the level of their extracellular activity through the action of a specific inhibitor, TIMP (tissue inhibitor of metalloproteinases), which irreversibly forms inactive complexes with metalloproteinases. Although the mechanisms governing the production of TIMP are unknown, immunologically identical forms of this glycoprotein have been detected in a wide variety of human body fluids and cell and tissue culture media. We therefore suggested that under physiological conditions this ubiquitous inhibitor predominates over active metalloproteinases and that tissue destruction may arise when any perturbation of this controlling excess arises. However, further progress towards testing this theory has been hindered by a lack of knowledge about the structure of TIMP and insufficient material for studying it in model systems. Here we describe the structure of TIMP predicted from its complementary DNA, its synthesis in Escherichia coli and transfected animal cells, and the finding that it is identical to a protein recently reported to have erythroid-potentiating activity (EPA).     

心肌肥厚大鼠血管膜周脂肪组织对血管舒缩功能的影响

目的:观察正常大鼠及部分结扎腹主动脉致心肌肥厚大鼠的血管膜周脂肪组织对血管舒缩功能的影响。方法:手术部分结扎腹主动脉致心肌肥厚模型,采用血管张力记录法,观察正常大鼠及模型大鼠血管膜周脂肪组织对血管舒缩功能的影响。结果:对于正常大鼠,血管膜周脂肪组织可显著降低血管对苯肾上腺素的反应性;对于模型鼠,血管膜周脂肪组织可显著升高血管对苯肾上腺素的反应性。结论:血管膜周脂肪组织对于血管的舒缩功能有重要的调节作用。     

心肌肥厚大鼠血管膜周脂肪组织对血管舒缩功能的影响

目的:观察正常大鼠及部分结扎腹主动脉致心肌肥厚大鼠的血管膜周脂肪组织对血管舒缩功能的影响.方法:手术部分结扎腹主动脉致心肌肥厚模型,采用血管张力记录法,观察正常大鼠及模型大鼠血管膜周脂肪组织对血管舒缩功能的影响.结果:对于正常大鼠,血管膜周脂肪组织可显著降低血管对苯肾上腺素的反应性;对于模型鼠,血管膜周脂肪组织可显著升高血管对苯肾上腺素的反应性.结论:血管膜周脂肪组织对于血管的舒缩功能有重要的调节作用.     

心肌肥厚大鼠血管膜周脂肪组织对血管舒缩功能的影响

目的观察正常大鼠及部分结扎腹主动脉致心肌肥厚大鼠的血管膜周脂肪组织对血管舒缩功能的影响.方法手术部分结扎腹主动脉致心肌肥厚模型,采用血管张力记录法,观察正常大鼠及模型大鼠血管膜周脂肪组织对血管舒缩功能的影响.结果对于正常大鼠,血管膜周脂肪组织可显著降低血管对苯肾上腺素的反应性;对于模型鼠,血管膜周脂肪组织可显著升高血管对苯肾上腺素的反应性.结论血管膜周脂肪组织对于血管的舒缩功能有重要的调节作用.     

Synchrotron refractive-index microradiography of human liver cancer tissue

Three human liver tissue samples （-5 mm × 40 mm × 20 mm） were excised from a cancer patient＇s liver during surgery. The microradiology analysis was performed with a non-standard approach on a synchrotron. High-resolution refractive-index edge-enhanced microradiographs that cover a larger volume of the liver tissue sample were obtained. The cancer tissue and normal tissue could be clearly identified and distinguished based on their different textures. Furthermore, new blood vessel hyperplasia was found near the cancer area. Blood vessels with a diameter smaller than 20 μm could be identified. These findings were fully consistent with the histopathological examination or the same area. Microradiographs of the newly formed blood vessels at different angles were also obtained. This result shows that it is possible to further develop this approach into a technique of microradiographic imaging for clinic diagnosis of liver cancer at the early stage.     

低温城市污水活性污泥脱氢酶活性变化的试验研究

以我国北方城市污水处理厂冬季低温运行的初沉池出水为原水,实验室模拟曝气池连续流运行,针对水温在15~3℃范围内,以2℃温差阶段性降低的过程,开展好氧活性污泥脱氢酶活性变化规律的研究。研究结果表明,污泥脱氢酶活性随温度降低总体呈下降趋势,温度由15℃降至13℃脱氢酶活性降低了41.42%,由13℃降至11℃降低约12.49%,在11~7℃范围内活性分别上升1.91%、1.96%,5℃相对7℃活性下降了7.82%。7℃时丝状菌出现增殖。3℃时污泥膨胀严重,脱氢酶活性上升了22.1%。     

一种大肠杆菌胆碱脱氢酶活性的测定方法

本文提出了一种简单易行的测定微生物中胆碱脱氢酶活力的方法。通过测定549nm波长下电子传递体系PMS(吩嗪二甲酯硫酸盐)-cty.c(细胞色素C)光吸收值的增加,就可以计算出胆碱脱氢酶活力。利用此方法测定了大肠杆菌胆碱脱氢酶热激诱导前后的活力,结果发现受到诱导的大肠杆菌中胆碱脱氢酶的活力明显高于对照组。     

青海本地山羊血清乳酸脱氢酶活性及其同功酶的研究

采用 2 ,4-二硝基苯肼比色法和聚丙烯酰胺凝胶电泳 (PAGE)法对青海本地山羊的血清乳酸脱氢酶 (LDH)活性及其同功酶酶谱进行了研究。结果 :①青海本地山羊血清LDH活性为( 1 1 3 2± 2 9 1 )U L ,且公、母山羊间无显著性差异 ;②被检山羊均呈单态 ,电泳显现出 5条LDH同功酶酶谱 ,经生物图像处理系统扫描定量其百分含量的排列顺序为 :LDH1>LDH3 >LDH2 >LDH4>LDH5,M亚基与H亚基之比 (M H)为 39% ,且公、母山羊之间相似。