Mesothelial differentiation as reflected by differential gene expression

Human mesothelial cells obtained from benign effusions retain their proliferative capacity and grow uniformly either with a fibroblastic or epithelioid morphology in vitro. These cultures therefore provide a model for the process of mesothelial differentiation in vivo. To study this differentiation, we isolated differentially expressed genes obtained by suppression subtractive hybridization. Of the nine genes found to be overexpressed in fibroblastic mesothelial cells, three are matrix-associated (integrin alpha5, collagen binding protein 2, human cartilage glycoprotein 39), whereas the others are associated with a proliferative cell type (14-3-3 epsilon, plexin B2, N33, and three genes encoding ribosomal elements). Seven of the eight genes upregulated in the epithelioid phenotype are related rather to specialized functions, such as metabolism (aldose reductase, lecithin:cholesterol acyltransferase, ATPase 6), cytoskeletal composition (cytokeratins 7 and 8), and regulation of differentiation (granulin, annexin II). Immunohistochemistry with available antibodies to six of the differentially expressed gene products confirmed the differences also in pleural tissues, where submesothelial cells displayed the fibroblastic markers, whereas surface cells displayed the epithelioid markers. In summary, this approach revealed a pattern of genes coordinately regulated during mesothelial differentiation and suggests that mesothelium may regenerate also by recruiting cells from the submesothelial layer. Some of the gene products may also be useful markers for differentiation and activation in serosal tissues.     

Effect of aging on neuroglobin expression in rodent brain

Neuroglobin (Ngb), a recently discovered O2-binding heme protein related to hemoglobin and myoglobin, protects neurons from hypoxic-ischemic injury in vitro and in vivo. In immunostained mouse brain sections, we found widespread expression of Ngb protein in neurons, but not astrocytes, of several brain regions that are prominently involved in age-related neurodegenerative disorders. Western blots from young adult (3 month), middle-aged (12 month), and aged (24 month) rats showed an age-related decline in Ngb expression in cerebral neocortex, hippocampus, caudate-putamen, and cerebellum. Loss of this neuroprotective protein may have a role in increasing susceptibility to age-related neurological disorders.     

医院实施ISO9001质量管理体系内部审核的探讨

医疗机构实施ISO9001,其目的是为了提高医疗服务质量,满足病人一切明确和隐含的需求。那么,内审是否发挥作用,直接关系管理体系的有效性。文章对此进行了初步的探讨,即:①明确内审的目的是检查体系满足标准要求的程度;②建立正规的内审机构,要选拔责任心强、综合素质高的人担任内审员;③编制合理且有特色的内审计划,是内审有效性的关键;④适当增加专题审核;⑤医院最高管理者应重视内审结果。     

Nucleotide mutations associated with hepatitis B e antigen negativity

One hundred and forty four patients with chronic hepatitis B were tested to identify new mutations associated with hepatitis B e antigen (HBeAg) negativity, using a full genome sequence analysis. All the patients were Chinese and had hepatitis B virus infection of genotype C. Patients with none of the pre-core or core promoter mutations were significantly (P < 0.001) less common in the group with anti-HBe (13%) than in the group with HBeAg (56%). The complete nucleotide sequence was determined in four anti-HBe-positive patients who had neither pre-core nor core promoter mutations and in five HBeAg-positive patients who also had neither of these mutations (the groups were matched for age and sex). Six mutations were found to be significantly more common in the former group than in the latter: G529A (3/4 vs. 0/5), C934A (4/4 vs. 1/5), A1053G (4/4 vs. 1/5), G1915T/A (4/4 vs. 0/5), T2005C/A (4/4 vs. 0/5), and C3026T (3/4 vs. 0/5). Three of the six mutations were significantly more common in the four anti-HBe-positive patients who had neither pre-core nor core promoter mutations, compared to 11 HBeAg-positive patients who had pre-core and core promoter mutations, and also compared to 15 anti-HBe-positive patients who had pre-core and core promoter mutations, suggesting further the specificity of these mutations. Of the six mutations, two resulted in amino acid substitution in the polymerase protein, and one is located near the enhancer I region. The results suggest that the six newly discovered mutations are associated with HBeAg negativity.     

High-performance liquid chromatography with peroxyoxalate chemiluminescence detection of bisphenol A migrated from polycarbonate baby bottles using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a label

A highly sensitive and selective high-performance liquid chromatographic method with peroxyoxalate chemiluminescence detection for the determination of bisphenol A at sub-ppb levels is described. Bisphenol A was derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride and the excess unreacted reagent was removed by a simple solid-phase extraction procedure with recoveries of approximately 60%. The separation was carried out isocratically on an ODS column and the derivatized bisphenol A was detected by peroxyoxalate chemiluminescence. A mixture of bis[2-(3,6,9-trioxadecanyloxycarbonyl)-4-nitrophenyl]oxalate (0.6 mM) and hydrogen peroxide (25.0 mM) dissolved in acetonitrile was used as a chemiluminescence reagent solution with a mixture of imidazole-HNO3 buffer (40.0 mM, pH 7.0): acetonitrile (17:83, v/v) as a mobile phase. The linear standard curve was obtained over the range from 0.57 (2.5) to 22.8 (100) ppb (nM) (r=0.996) with a detection limit of 0.38 ppb (2.8 fmol on column) at a signal-to-noise ratio of 3. The method was successfully applied to the determination of bisphenol A in hot water in contact with commercially available baby bottle samples.     

人工假肢膝关节微电脑控制装置的研究

高位截肢的伤残病人，即使安装了人工假肢，也因为人工假肢的关节不能自由活动，因而行走起来很吃力，动作不协调，姿态不美观。如果在人工假肢的关节处安装一个步进电机，采用微电脑控制技术，使步进电机按照人的意志转动，那么人在行走（或奔跑、弹跳、上下楼梯、下蹬起立等）时，假肢的逼真程度将会大大提高，动作也就十分自然。本文就这种构想谈了制作过程。     

An improved method for utilization of peptide substrates for antibody characterization and enzymatic assays

Synthetic peptides have become an important tool in antibody production and enzyme characterization. The small size of peptides, however, has hindered their use in assays systems, such as Western blots, and as immunogens. Here, we present a facile method to improve the properties of peptides for multiple applications by ligating the peptides to intein-generated carrier proteins. The stoichiometric ligation of peptide and carrier achieved by intein-mediated protein ligation (IPL) results in the ligation product migrating as a single band on a SDS-PAGE gel. The carrier proteins, HhaI methylase (M.HhaI) and maltose-binding protein (MBP), were ligated to various peptides; the ligated carrier-peptide products gave sharp, reproducible bands when used as positive controls for antibodies raised against the same peptides during Western blot analysis. We further show that ligation of the peptide antigens to a different thioester-tagged carrier protein, paramyosin, produced immunogens for the production of antisera in rabbits or mice. Furthermore, we demonstrate the generation of a substrate for enzymatic assays by ligating a peptide containing the phosphorylation site for Abl protein tyrosine kinase to a carrier protein. This carrier-peptide protein was used as a kinase substrate that could easily be tested for phosphorylation using a phosphotyrosine antibody in Western blot analysis. These techniques do not require sophisticated equipment, reagents, or skills thereby providing a simple method for research and development.     

Improved controlled release study of lomustine

Lomustine (CCNU) microcapsules was prepared by improved recoacervation method, then mixed microcapsules with 0.7% collagen swelling solution to prepare the emulsion, spreaded the emulsion on the plate to form membrane and cross-linked it, the membrane would be planted into body and was expected to release at steady speed. The concentration of CCNU and the CCNU content of microcapsules were measured by ultraviolet spectrophotometry to observe the release of CCNU be slow and constant, approach to 0-class release approximately.     

Antigenicity of cryopreserved arterial allografts: comparison with fresh and glutaraldehyde treated grafts

The use of cryopreserved aortic allografts in cardiovascular surgery is widespread and has resulted in excellent outcomes. However, it is controversial whether cryopreservation suppresses the antigenicity of tissue. We designed experimental models to study whether the cryopreservation process alters antigenicity in comparison with that found in fresh and glutaraldehyde treated tissues. Fresh, cryopreserved, and glutaraldehyde treated thoracic aorta from Brown Norway rats were subcutaneously implanted into Lewis rats. Inflammatory cells infiltrating around the grafts were measured on days 7, 14, 28, and 56 after implantation. The glutaraldehyde treated grafts showed significantly less infiltration than the fresh or cryopreserved grafts (p < 0.005). No significant difference was detected between the fresh and cryopreserved grafts. Another study examined the effect of modifications of the aortic allograft on subsequent allogeneic skin graft antigenicity. Subcutaneous implantation of fresh, cryopreserved, and glutaraldehyde treated aortic grafts from Brown Norway into Lewis rats resulted in subsequent skin graft rejection at 4.4+/-0.7, 5.1+/-0.8, and 6.6+/-2.1 days, respectively. There was no significant difference between the fresh and cryopreserved groups; whereas skin grafts in the glutaraldehyde group survived longer than those in the cryopreserved group. These results indicate that cryopreservation had no significant influence on antigenic suppression of arterial allografts.     

Simultaneous measurements of temperature and pH in vivo using NMR in conjunction with TmDOTP5-

NMR techniques for temperature and pH measurements have attracted increasing interest in recent years, motivated in part by the growing importance of medical hyperthermia for the treatment of cancer. The chemical shifts of thulium 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetrakis(methylene phosphonate) (TmDOTP5-) have been studied as a function of temperature and pH. The results demonstrate that TmDOTP5- resonance shifts are highly sensitive to temperature (approximately 1.0 ppm/degrees C) and pH (approximately 3.2 ppm/pH unit) at clinically relevant field strengths. A new method is presented which utilizes two magnetically non-equivalent protons in TmDOTP5- for simultaneous NMR measurements of both temperature and pH. The difference in the chemical shift values of pairs of 1H resonances provides a temperature sensitivity of about 1.6 ppm/ degrees C. The technique is demonstrated in live rats undergoing ultrasound-induced hyperthermia therapy.