利舒康胶囊对50例高原红细胞增多症患者体内同型半胱氨酸水平的调节作用

目的:观察利舒康胶囊对高原红细胞增多症(HAPC)患者体内同型半胱氨酸(Hcy)水平的影响。方法:在海拔3300m地区选择50例HAPC患者采用利舒康胶囊(手掌参、唐古特青兰、烈香杜鹃、红景天等)治疗前后血中H cy含量的测定。结果:HAPC患者经利舒康胶囊治疗40d后,血中Hcy含量明显下降(P<0.01)。提示:表明利舒康胶囊对高原细胞增多症患者体内的同型半胱氨酸水平具有良好的调节和改善作用。

S-烯丙基-L-半胱氨酸对抗离体大鼠心肌缺血/再灌损伤作用的研究

目的:探讨S-烯丙基-L-半胱氨酸(SAC)预处理对心肌缺血/再灌(I/R)损伤的保护作用及其机制。方法:采用离体大鼠心脏Langendorff灌流模型,全心停灌30 min,再灌120 min建立I/R模型。测定血流动力学指标和再灌各时间点冠脉流出液中乳酸脱氢酶(LDH)含量。实验结束测心肌组织中甲月赞(formazan),超氧歧化酶(SOD)及活性氧(ROS)量的变化。结果:与对照组比,SAC明显改善左室血流动力学指标,提高心肌组织的formazan含量,降低再灌期间冠脉流出液中LDH含量,提高心肌组织中SOD的活性,降低心肌组织中ROS的水平。苏氨酸明显减弱SAC的保护作用。结论:SAC对离体大鼠I/R心肌损伤有保护作用,其机制可能与SAC通过心肌细胞膜上的氨基酸转运体ASCT-1进入心肌细胞,增加心肌SOD活性,减少活性氧的损伤有关。

Particularly interesting new cysteine-histidine rich protein expression in colorectal adenocarcinomas

AIM： To study the relationship between particularly interesting new cysteine-histidine rich protein （PINCH） expression and clinicopathological factors in Chinese colorectal cancer patients. METHODS： The expression of PINCH was examined by immumohistochemistry in 141 samples of primary colorectal adenocarcinoma and 92 normal samples of colorectal mucosa. Eighty of the cases had both primary tumour and normal mucosa from the same patients. RESULTS： PINCH was expressed in the stroma of normal mucosa and tumours. PINCH expression in tumourassociated stroma was increased compared to normal mucosa in both unmatched cases （n = 141, x^2 = 85.79, df = 3, P〈 0.0001） and matched cases （n =80, x^2= 45.86, df= 3, P〈 0.0001）. Among 135 tumours with visible invasive margin, 86 （64%） showed stronger PINCH expression at the invasive margin than in the intratumoural stroma. The frequency of PINCH strong expression in mucinous and signet-ring cell carcinomas was higher （52%） compared to non-mucinous carcinomas （29%, x^2=5.13, P= 0.02）. We did not find that PINCH expres- sion was related to patient＇s gender, age, tumour location, tumour size, gross status, histological type, differentiation, invasion depth, lymph node status and Dukes＇ stage （P 〉 0.05）.CONCLUSION： The expression of PINCH was upregulated in colorectal cancers, and especially at the margin of tumours, and further was related to mucinous and signet-ring cell carcinomas. The results suggest that expression of PINCH may be involved in the tumourigenesis and aggressiveness of colorectal cancers.

Magnetoelectrochemical Chirality in Ag E lectrod e position

Chiral behaviors of magnetoelectrodeposited Ag film electrodes were investigated for the electrochemical reactions of glucose and cysteine. The Ag films were electrodeposited under a magnetic field of 2 T perpendicular to the electrode surface at various potentials 0f-0.06-0.4 V （vs Ag I Ag＋）. The current-time curves during the electrodeposition and the surface morphology of the films implied that the film growth was considerably affected by the micro-MHD （magnetohydrodynamic） effect. Such Ag films were employed as an electrode, and voltammograms of glucose and cysteine were examined. Chiral behavior was clearly observed as current difference between the enantiomers on the film electrodes prepared at electrodeposition potentials less than -0.1 V. Such electrochemical chirality disappeared after the oxidation and reduction of the surface monolayer, and this fact indicates that the chiral sites must be just on the film surface.

Chemical interactions between silver nanoparticles and thiols: a comparison of mercaptohexanol against cysteine

The interaction between citrate capped silver nanoparticles and two different thiols, mercaptohexanol （MH） and cysteine, was investigated. The thiols interacted with silver nanoparticles in a significantly contrasting manner. With MH, a sparingly soluble silver（1） thiolate complex AgSRm （Rm = -（CH2）6OH） was formed on the silver nanoparticle surface. Cyclic voltammograms and UV-vis spectra were used to infer that the AgSRm complex on the nanoparticle surface undergoes a phase transition to give a mixture of AgSRm and Ag2S-like complexes. In contrast, when silver nanoparticles were exposed to cysteine, the citrate cap- ping agent on the silver nanoparticles was replaced by cysteine to give cysteine capped nanoparticles. As cysteine capped nanoparticles form, the electrochemical data displayed a decrease in oxidative peak charge but the UV-vis spectra showed a constant signal. Therefore, cysteine capped nanoparticles were suggested to have either inactivated the silver surface or else pro- moted detachment from the electrode surface.

Structural and biochemical insights into the homotypic PB1-PB1 complex between PKCζ and p62

The atypical PKC isoforms （ζ and t） play essential roles in regulating various cellular processes. Both the hetero-interaction between PKCζand p62 through their N-terminal PB 1 domains and the homo-oligomerization of p62 via its PB 1 domain are critical for the activation of NF-r.B signaling; however, the molecular mechanisms concerning the formation and regulation of these homotypic complexes remain unclear. Here we determined the crystal structure of PKCζ-PB 1 in complex with a mono- meric p62-PB 1 mutant, where the massive electrostatic interactions between the acidic OPCA motif of PKCζ-PB 1 and the basic surface of p62-PB 1, as well as additional hydrogen bonds, ensure the formation of a stable and specific complex. The PKCζ-p62 interaction is interfered with the modification of a specific Cys of PKCζ by the antiarthritis drug aurothiomalate, though all four cysteine residues in the PKCζ-PB 1 domain can be modified in in vitro assay. In addition, detailed structural and biochemical analyses demonstrate that the PB 1 domains of aPKCs belong to the type I group, which can depolymerize the high-molecular-weight p62 aggregates into homo-oligomers of lower order. These data together unravel the molecular mecha- nisms of the homo- or hetero-interactions between p62 and PKCζ and provide the basis for designing inhibitors of NF-r,.B sig- naling.

Oxidation and detection of L-cysteine using a modified Au/Nafion/glass carbon electrode

In this work,the electrochemical oxidation of L-cysteine(CySH)was investigated on a composite film modified electrode with Au nanoparticles dispersed in the fluorocarbon polymer(Nafion).The excellent electrocatalytic effect on CySH oxidation was attributed to the role of Au nanoparticles.The voltammetric studies revealed two anodic peaks for the oxidation of CySH in the pH range of 2.0–8.0.The electrode was used to detect cysteine at pH 2.0 and pH 7.0.At pH 2.0,a determination range of 3.0–50.0?mol/L was obtained with the detection sensitivity of 22.7A/(mmol L1),while at pH 7.0,a determination range of 2.0–80.0mol/L was obtained with the detection sensitivity of 4.08A/(mmol L1).The detection limits were estimated to be as low as 1.0?mol/L at both pH 7.0 and pH 2.0.Additionally,at pH 7.0,the interferences of ascorbic acid and uric acid were reduced for the detection of cysteine.These made the Au/Nafion/GC electrode a promising candidate for efficient electrochemical sensors for the detection of CySH.