基于HPLC-ABTS体系筛选细叶杜香抗氧化活性成分

细叶杜香(Ledum palustre L.var.Angustum E.Busch)是我国北方常用药用材料,有止咳祛痰、平喘、扩张血管等功效.本文利用HPLC-ABTS+在线筛选体系对细叶杜香茎部的抗氧化活性成分进行了筛选和分析检测,实验结果表明:细叶杜香茎部甲醇提取物中含有大量抗氧化活性成分,其中经二氯甲烷萃取后纯...     

Thermal treatment of titanate derivatives synthesized by host-guest reaction

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

A study of a series of recombinant fungal laccases and bilirubin oxidase that exhibit significant differences in redox potential, substrate specificity, and stability

A series of fungal laccases (Polyporus pinsitus, Rhizoctonia solani, Myceliophthora thermophila, Scytalidium thermophilum) and one bilirubin oxidase (Myrothecium verrucaria) have been studied to determine their redox potential, specificity, and stability. Polyporus and Rhizoctonia laccases possess potentials near 0.7-0.8 V (vs. NHE), while other oxidases have potentials near 0.5 V. It is observed that higher redox potential correlates with higher activity. By EPR, no significant change in the geometry of type 1 copper (II) site is observed over this series. At the optimal pH, the two substrates studied, 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) and syringaldazine, show Km values ranging form 10 to 120 and from 1 to 45 microM; and kcat values ranging from 50 to 16 000 and 200 to 3000 per min, respectively. The enzymes are more stable in the neutral-alkaline pH range. The thermal stability is in the order of bilirubin oxidase equivalent to Myceliophthora laccase equivalent to Scytalidium laccase > Polyporus laccase > Rhizoctonia laccase. Based on these results and the sequence alignments made against Zucchini ascorbate oxidase it is speculated that structural differences in the substrate-activation site (a 'blue', type 1 copper center) control the redox potential range as well as substrate specificity, and the cystine content contributes to stability.     

CD63 is a component of Weibel-Palade bodies of human endothelial cells

Weibel-Palade bodies are secretory granules of vascular endothelial cells specialized in the storage of von Willebrand factor (vWF) and P-selectin, two adhesion proteins that can be rapidly mobilized to the cell surface by exocytosis in response to thrombin or other agonists. In this study, we attempted to identify additional components of Weibel-Palade bodies by raising monoclonal antibodies to these granules, purified by cell fractionation. One antibody, 2C6, was found to be specific for CD63, a membrane glycoprotein previously described in the lysosomes of platelets and other cell types. The immunopurified 2C6 antigen was recognized by an anti-CD63 reference antibody, 2.28, by Western blotting. Also, the biosynthetic profile of the 2C6 antigen in endothelial cells showed a nascent molecular mass and a glycosylation pattern identical to that of CD63. Immunofluorescence staining with 2C6 showed the lysosomes, and also elongated structures identified as Weibel-Palade bodies by their shape, distribution, and positive staining with anti-vWF antibodies, CD63 was also found by Western blotting of subcellular fractions highly enriched in Weibel-Palade bodies. Our results indicate that CD63 colocalizes with vWF and P-selectin in the Weibel-Palade bodies of endothelial cells, and together with these adhesion proteins it could be rapidly expressed on the cell surface in areas of vascular injury and inflammation.     

Intestinal epithelial restitution. Involvement of specific laminin isoforms and integrin laminin receptors in wound closure of a transformed model epithelium

Disruptions in the mucosal lining of the gastrointestinal tract reseal by epithelial cell migration, a process termed restitution. We examined the involvement of laminin isoforms and their integrin receptors in restitution using the intestinal epithelial cell line T84. T84 cells express primarily laminins 5, 6, and 7 as indicated by immunostaining using laminin subunit-specific monoclonal antibodies (MAbs). A MAb (BM2) specific for the laminin alpha 3 subunit, a component of laminins 5, 6, and 7, completely inhibited the closure of mechanical wounds in T84 monolayers. Confocal microscopy using MAbs BM2 (laminin alpha 3 subunit) and 6F12 (laminin beta 3 subunit) revealed that laminin-5 is deposited in a basal matrix that extends into the wound. The MAbs 4E10 (laminin beta 1 subunit) and C4 (laminin beta 2 subunit) stained the lateral membranes between T84 cells. This staining was enhanced in cells adjoining wounds. Because T84 cells stained faintly with MAbs 4C7 (laminin alpha 1 subunit) and with MAbs 4F11 and 1B4 (laminin alpha 2 subunit), we suggest that expression of laminins 6 and 7 is enhanced in response to wounding. The alpha 3 beta 1 integrin and the alpha 6-containing integrins function in wound closure because MAbs specific for the beta 1 integrin subunit (MAb13), the alpha 3 subunit (IVA5), and the alpha 6 subunit (2B7) potently inhibited T84 migration into wounds. Immunofluorescence using UMA9, a beta 4-integrin-specific MAb, revealed that alpha 6 beta 4 integrin exists in a Triton-X-100-insoluble structure at the basal surface and that the staining of this structure is enhanced in cells adjoining wounds. In addition, a Triton-X-100-soluble pool of alpha 6 beta 4, as well as alpha 3 beta 1 and presumably alpha 6 beta 1, was found along lateral surfaces of T84 cells. On flattened cells adjoining wounds, staining for these integrins was distributed diffusely, suggesting a redistribution that accompanies cell migration. Taken together, these data suggest that wound-induced epithelial cell migration is a finely tuned process that is dependent upon the regulated function and localization of specific laminins and their integrin receptors.     

Functional coupling of phosphatidylinositol 4,5-bisphosphate to inositol 1,4,5-trisphosphate receptor

The inositol 1,4,5-trisphosphate receptor (InsP3R) plays a key role in intracellular Ca2+ signaling. InsP3R is activated by InsP3 produced from phosphatidylinositol 4,5-bisphosphate (PIP2) by phospholipase C cleavage. Using planar lipid bilayer reconstitution technique, we demonstrate here that rat cerebellar InsP3R forms a stable inhibitory complex with endogenous PIP2. Disruption of InsP3R-PIP2 interaction by specific anti-PIP2 monoclonal antibody resulted in 3-4-fold increase in InsP3R activity and 10-fold shift in apparent affinity for InsP3. Exogenously added PIP2 blocks InsP3 binding to InsP3R and inhibits InsP3R activity. Similar results were obtained with a newly synthesized water soluble analog of PIP2, dioctanoyl-(4,5)PIP2, indicating that insertion of PIP2 into membrane is not required to exert its inhibitory effects on the InsP3R. We hypothesize that the functional link between InsP3R and PIP2 described in the present report provides a basis for a local, rapid, and efficient coupling between phospholipase C activation, PIP2 hydrolysis, and intracellular Ca2+ wave initiation in neuronal and non-neuronal cells.     

Two cases of benign vaginal rhabdomyoma. Case reports

Two cases of benign vaginal rhabdomyoma, which occurred in women aged 38 and 54 years, are reported. The macroscopic and microscopic appearance is described. The literature on this rare tumour is reviewed and the differential diagnoses are discussed. Local excision is considered adequate treatment.     

Health status of former elite athletes. The Finnish experience

A 71-year-old man was found dead in a car into which exhaust fumes had been introduced. His wife who was in the same car recovered consciousness following hospitalization. She claimed that they had both attempted suicide by taking a large number of sleeping pills. Autopsy revealed no significant external injuries or medical disorders that would have led to the husband's death. The concentrations of alcohol and carbon-monoxide hemoglobin in his whole blood were 0.26 mg/ml and < 10%, respectively. Therefore, poisoning by carbon monoxide from the exhaust fumes was ruled out, and further toxicological examinations were undertaken. Triazolam, pentobarbital, amitriptyline and bromazepam were all detected in the tissues of the victim; whole blood concentrations were 45.60, 386.4, 521.2 and 166.7 ng/g, respectively. Triazolam (7.350 ng/g) and pentobarbital (288.2 ng/g) were also detected in the whole blood of the wife, collected 17 h after admission to hospital. When evaluating these results in the light of existing literature, we concluded that the victim and his wife had indeed attempted suicide by taking triazolam and pentobarbital. However, only the man had died of triazolam poisoning due to its apparently lethal combination with amitriptyline and other psychotropic drugs which had been prescribed to treat his depression.     

Low LDL oxidation in veteran endurance athletes

In this observational study, multiplanar three-dimensional ultrasound images were reconstructed from tomographic views obtained by scanning seven cadavaric fetal hearts with various congenital heart defects. Comparisons were made with multiplanar three-dimensional magnetic resonance imaging (MRI) of the hearts. Good-quality echocardiographic images were obtained in all but one of the fetal hearts. Multiplanar as well as three-dimensional reconstructions were possible and allowed accurate assessment of complex cardiac defects. Overall, the MRI projections had better image quality and revealed more structural details than the sonographic views, although both imaging modes showed the same cardiac anatomical abnormalities. Our initial results demonstrate that simultaneous multiplanar display of cross-sectional echocardiographic views can be performed to provide three-dimensional images of the fetal heart, demonstrating structural cardiac malformation. However, the clinical application of three-dimensional fetal echocardiography is at present limited by the time required for image data acquisition and the need for accurate temporal and positional gating in the living fetus.