灰树花多肽-钙螯合物对小鼠衰老性骨质疏松的改善作用

通过建立D-半乳糖致衰老性骨质疏松(SOP)小鼠模型,探讨灰树花多肽-钙螯合物(GPs-Ca)对SOP的改善作用;通过体外Caco-2单细胞层模型模拟研究灰树花多肽-钙螯合物的促钙吸收能力.将50只雄性ICR小鼠随机分为5组,除了空白对照组外,其它4组均给予腹腔注射D-半乳糖;空白对照组给予腹腔注射同等剂量的生理盐水....     

Free Radical Generation in Far-UV Synchrotron Radiation Circular Dichroism Assays—Protein and Buffer Composition Contribution

A useful tool to analyze the ligands and/or environmental contribution to protein stability is represented by the Synchrotron Radiation Circular Dichroism UV-denaturation assay that consists in the acquisition of several consecutive repeated far-UV SRCD spectra. Recently we demonstrated that the prevailing mechanism of this denaturation involves the generation of free radicals and reactive oxygen species (ROS). In this work, we analyzed the effect of buffering agents commonly used in spectroscopic measurements, including MOPS (3-(N-morpholino) propanesulfonic acid), HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid), TRIS-HCl (tris-hydroxymethil aminomethane hydrochloride), and phosphate, on the efficiency of protein denaturation caused by exposure to UV radiation. Fluorescence experiments confirmed the presence of ROS and were used to determine the rate of ROS generation. Our results indicate that the efficiency of the denaturation process is strongly influenced by the buffer composition with MOPS and HEPES acting also as scavengers and that the presence of proteins itself influenced the ROS formation rate.     

关于重庆市取消生化池的探讨

本文通过分析化粪池和生化池在实际使用中的一些问题,结合重庆市实际情况,对在城市污水厂服务区域内取消化粪池和生化池进行了探讨。     

Chemical Tools for Studying Phosphohistidine: Generation of Selective τ-Phosphohistidine and π-Phosphohistidine Antibodies**

Nonhydrolysable stable analogues of τ-phosphohistidine (τ-pHis) and π-pHis have been designed, aided by electrostatic surface potential calculations, and subsequently synthesized. The τ-pHis and π-pHis analogues (phosphopyrazole 8 and pyridyl amino amide 13 , respectively) were used as haptens to generate pHis polyclonal antibodies. Both τ-pHis and π-pHis conjugates in the form of BSA-glutaraldehyde-τ-pHis and BSA-glutaraldehyde-π-pHis were synthesized and characterized by ³¹P NMR spectroscopy. Commercially available τ-pHis (SC56-2) and π-pHis (SC1-1; SC50-3) monoclonal antibodies were used to show that the BSA−G-τ-pHis and BSA−G-π-pHis conjugates could be used to assess the selectivity of pHis antibodies in a competitive ELISA. Subsequently, the selectivity of the pHis antibodies generated by using phosphopyrazole 8 and pyridyl amino amide 13 as haptens was assessed by competitive ELISA against His, pSer, pThr, pTyr, τ-pHis and π-pHis. Antibodies generated by using phosphopyrazole 8 as a hapten were found to be selective for τ-pHis, and antibodies generated by using pyridyl amino amide 13 were found to be selective for π-pHis. Both τ- and π-pHis antibodies were shown to be effective in immunological experiments, including ELISA, western blot, and immunofluorescence. The τ-pHis antibody was also shown to be useful in the immunoprecipitation of proteins containing pHis.     

Different effects of the methods of administering lactoferrin,IGF-1 and IgG from bovine colostrum to rabbits based on the cytokine communication network

Lactoferrin, IGF-1 and IgG are three well-known bioactive proteins found in bovine colostrum. We studied the effects of these three active ingredients on the levels of eight cytokines in serum and on the cellular communication networks in vivo by oral administration, intraperitoneal injection and intravenous injection. The results suggested that bioactive ingredients, especially biomacromolecules, can induce different effects, even opposite effects, on the immune system depending on the route of administration. These effects are related to both the functions of the bioactive ingredient in vivo and to its specific receptor binding in the gastrointestinal mucosa that activates different signalling pathways.