Immune reactions associated with silicone-based ventriculo-peritoneal shunt malfunctions in children

The implantation of ventriculo-peritoneal (VP) shunting systems is the most commonly performed neurological procedure in children with hydrocephalus. Although the overall complication risk is low, the cumulative risk of shunt failure is high and unfortunately results in a high prevalence of revision surgeries. In this study, we explored the concept that some pediatric patients may develop an immune response to either the proteins attached to the silicone implant surface or to the biomaterial itself, and that this reaction may contribute to VP shunt failure in some individuals. The data displays that the sterile shunt malfunction group had a higher rate of protein deposition and increased levels of autoantibodies to the extracted surface proteins as compared to individuals with functioning shunting systems. The precise nature of the shunt-bound proteins that serve as antigens in this experiment have not yet been determined. The data also indicated that some individuals develop antibodies to polymeric substances that cross-react with partially polymerized acrylamide. The detection of significant amounts of shunt-bound protein, antibody responses to these proteins and to polymeric substances suggest that an immunological response to these proteins may play a role in the mechanism behind sterile shunt malfunctions.     

Thr123 of rat G-substrate contributes to its action as a protein phosphatase inhibitor

Rat G-substrate cDNA was isolated from a cerebellar library and characterized. The deduced amino acid sequence of rat G-substrate contained two putative phosphorylation sites for PKG at Thr72 and Thr123; the amino acid sequences (KPRRKDT(p)PA) around these sites are conserved in human, mouse and rabbit. G-substrate phosphorylated by PKG inhibited the catalytic subunits of both protein phosphatase-1 (IC(50) 14.1 nM) and -2A (IC(50) 5.9 nM). Mutation of Thr123 (site 2) to Ala significantly reduced the inhibition of both PP-1 and PP-2A, while mutation of Thr72 (site 1) to Ala had little effect on inhibitory activity. In situ hybridization analysis revealed that G-substrate mRNA was localized exclusively in cerebellar Purkinje cells. Immunoperoxidase staining showed that in Purkinje cells, G-substrate was present in somata, dendrites and axons. In rat cerebellar slices, activation of PKG with a nitric oxide (NO) donor, NOR3, or 8-Br-cGMP, increased phosphorylation of G-substrate, as demonstrated with a phosphorylation-specific antibody. These results characterize further the inhibition of PP-1 and PP-2A by phospho-G-substrate, and demonstrate its physiological phosphorylation in rat Purkinje cells.     

幽门螺杆菌对SGC-7901细胞增殖凋亡及p27kipl表达的影响

Objective To explore the influence of Helicobacter pylori (Hp) on the proliferation, apoptosis and expression of p27kipl protein of gastric epithelial cells in vitro. Methods SC, C-7901 cell pro-liferation was examined by flow cytometry after incubation with different concentration of NCTC11637. The effect of NCTC11637 on cell apoptosis was also evaluated by flow cytometryo And the expression of p27kipl of gastric epithelial cells was detected by immunohistochemical analysis and in situ hybridization, respectively. Results Cell proliferation was enhanced when co-incubated with the Hp in low concentration (3.4 x 104 to 1.9 x 105 CFU/ml) but inhibited in higher concentration (≥4.8×106CFU/ml). However, cell apoptosis was increase when co-incubated with the Hp in high concentration (≥9.6 ×105 CFU/ml) showing concen-tration dependent picture. In addition, the co-incubation of SGC-7901 with Hp led to decrease of the expres-sion of p27kipl protein but not mRNA in a Hp concentration dependent way. Conclusion Hp could effect the gastric epithelial cells apoptosis and proliferation directly and influence the expression of p27kips protein which might facilitate gastric carcinoma.     

构建肿瘤坏死因子-α免疫微球的实验研究

前瞻性构建肿瘤坏死因子-α免疫微球,以期为将来进一步研究能应用于特异性清除TNF-α的血液净化方法,奠定实验基础。采用以PSM为载体,依次包被PLL及rHTNF-αM cA b的方法而制备的免疫微球,分别以异硫氰酸荧光素标记,应用倒置显微镜及荧光显微镜观察、分光光度计测定等方法,探讨吸附微球的包被条件。结果显示,20℃、pH 9.5、60 m in三者为PLL包被PSM的最佳条件。包被后的洗脱液检测结果显示PLL含量无明显变化,说明PLL在PSM表面包被较为牢固。在相同温度及包被时间内,应用浓度为0.2%的戊二醛溶液进行的rHTNF-αM cA b对PLL的包被结合牢固。实验表明,所构建的肿瘤坏死因子-α免疫微球,达到了预期的目的,可以作为一种新颖的免疫吸附材料。该方法简单,价格便宜,为相关实验研究提供了一种崭新方法。     

Analysis of orthologous gene expression between human pulmonary adenocarcinoma and a carcinogen-induced murine model

Human adenocarcinoma (AC) is the most frequently diagnosed human lung cancer, and its absolute incidence is increasing dramatically. Compared to human lung AC, the A/J mouse-urethane model exhibits similar histological appearance and molecular changes. We examined the gene expression profiles of human and murine lung tissues (normal or AC) and compared the two species' datasets after aligning approximately 7500 orthologous genes. A list of 409 gene classifiers (P value <0.0001), common to both species (joint classifiers), showed significant, positive correlation in expression levels between the two species. A number of previously reported expression changes were recapitulated in both species, such as changes in glycolytic enzymes and cell-cycle proteins. Unexpectedly, joint classifiers in angiogenesis were uniformly down-regulated in tumor tissues. The eicosanoid pathway enzymes prostacyclin synthase (PGIS) and inducible prostaglandin E(2) synthase (PGES) were joint classifiers that showed opposite effects in lung AC (PGIS down-regulated; PGES up-regulated). Finally, tissue microarrays identified the same protein expression pattern for PGIS and PGES in 108 different non-small cell lung cancer biopsies, and the detection of PGIS had statistically significant prognostic value in patient survival. Thus, the A/J mouse-urethane model reflects significant molecular details of human lung AC, and comparison of changes in orthologous gene expression may provide novel insights into lung carcinogenesis.     

Analysis of microdissected prostate tissue with ProteinChip arrays--a way to new insights into carcinogenesis and to diagnostic tools

Prostate carcinomas are one of the most common malignancies in western societies. The pathogenesis of this tumor is still poorly understood. These tumors present with two characteristic features: epithelial-mesenchymal interactions, which play a pivotal role for tumor development and most of clinically manifest cancers arise in prostate proper compared to a minority of tumors which develop in the transitional zone. Deciphering the epithelial-mesenchymal cross talk and identification of molecular pecularities of the sub-populations of cells in different zones can therefore help understanding carcinogenesis and development of new, non-invasive tools for the diagnosis and prognosis of prostate carcinomas which has remained a challenge until today. A ProteinChip array technology (SELDI = surface enhanced laser desorption ionization) has been developed recently by Ciphergen Biosystems enabling analysis and profiling of complex protein mixtures from a few cells. This study describes the analysis of approximately 500-1000 freshly obtained prostate cells by SELDI-TOF-MS (surface enhanced laser desorption ionization time-of-flight mass spectrometry). Pure cell populations of stroma, epithelium and tumor cells were selected by laser assisted microdissection. Multiple specific protein patterns were reproducibly detected in the range from 1.5 to 30 kDa in 28 sub-populations of 4 tumorous prostates and 1 control. A specific 4.3 kDa peak was increased in the prostate tumor stroma compared to normal prostate proper and transitional zone stroma and increased in prostate tumor glands compared to normal prostate proper and transitional zone glands. Coupling laser assisted microdissection with SELDI provides tremendous opportunities to identify cell and tumor specific proteins to understand molecular events underlying prostate carcinoma development. It underlines the vast potential of this technology to better understand pathogenesis and identify potential candidates for new specific biomarkers in general which could help to screen for and distinguish disease entities, i.e. between clinically significant and insignificant carcinomas of the prostate.     

Clara cell secretory protein deficiency alters clara cell secretory apparatus and the protein composition of airway lining fluid

Clara cells represent the predominant secretory cell within distal conducting airways of mammals and exhibit functional alterations with chronic lung disease. We previously demonstrated that Clara cell secretory protein (CCSP) deficiency results in enhanced susceptibility to environmental agents. The present study was undertaken to define changes in Clara cell secretory function associated with CCSP deficiency in knockout mice. Comparative morphometry of Clara cell ultrastructure revealed dramatic alterations in secretory apparatus between wild-type (WT) and CCSP knockout (CCSP-/-) mice. Secretory granules, which occupy greater than 2% of Clara cell cytoplasmic volume in WT mice, were completely absent among Clara cells of CCSP-/- mice. Moreover, Clara cells of CCSP-/- mice exhibited a > 95% reduction in rough endoplasmic reticulum and alterations to Golgi apparatus, relative to WT controls. Ultrastructural perturbations to Clara cells were associated with altered protein composition of airway lining fluid as revealed by two-dimensional gel analysis of bronchoalveolar lavage proteins, but were not associated with altered abundance or secretion of CC26, another Clara cell secretory protein. We conclude that CCSP is required for the appearance of Clara cell secretory granules and that functional changes to Clara cells that result from CCSP deficiency lead to alterations in the composition of epithelial lining fluid.