Functional polymer laminates from hyperthermal hydrogen induced cross-linking.

The use of a hyperthermal hydrogen induced cross-linking process to prepare laminates comprising polypropylene, poly(isobutylene-co-isoprene), and poly(vinyl acetate) is described. In this new, milder alternative to conventional plasma techniques, neutral molecular hydrogen projectiles were used to create carbon radicals on impacted surfaces by collision-induced dissociation of C-H bonds, and this process was used to cross-link polymers on a polypropylene surface. It was demonstrated that multiple layers of cross-linked materials could be added, creating polymer laminates with each layer introducing new functionalities and properties. In particular, the present work shows that the process is largely nondestructive toward ester functionalities. First, the esters were grafted to become nonleachable. Then, the esters were subsequently hydrolyzed to convert the surface from hydrophobic to hydrophilic. Afterward, the esters could be recovered by simple esterification demonstrating that further chemical transformations were possible.

Preparation of protein- and cell-resistant surfaces by hyperthermal hydrogen induced cross-linking of poly(ethylene oxide).

The functionalization of surfaces with poly(ethylene oxide) (PEO) is an effective means of imparting resistance to the adsorption of proteins and the attachment and growth of cells, properties that are critical for many biomedical applications. In this work, a new hyperthermal hydrogen induced cross-linking (HHIC) method was explored as a simple one-step approach for attaching PEO to surfaces through the selective cleavage of C-H bonds and subsequent cross-linking of the resulting carbon radicals. In order to study the effects of the process on the polymer, PEO-coated silicon wafers were prepared and the effects of different treatment times were investigated. Subsequently, using an optimized treatment time and a modified butyl polymer with increased affinity for PEO, the technique was applied to butyl rubber surfaces. All of the treated surfaces exhibited significantly reduced protein adsorption and cell growth relative to control surfaces and compared favorably with surfaces that were functionalized with PEO using conventional chemical methods. Thus HHIC is a simple and effective means of attaching PEO to non-functional polymer surfaces.

An XML-based interchange format for genotype-phenotype data.

Recent advances in high-throughput genotyping and phenotyping have accelerated the creation of pharmacogenomic data. Consequently, the community requires standard formats to exchange large amounts of diverse information. To facilitate the transfer of pharmacogenomics data between databases and analysis packages, we have created a standard XML (eXtensible Markup Language) schema that describes both genotype and phenotype data as well as associated metadata. The schema accommodates information regarding genes, drugs, diseases, experimental methods, genomic/RNA/protein sequences, subjects, subject groups, and literature. The Pharmacogenetics and Pharmacogenomics Knowledge Base (PharmGKB; www.pharmgkb.org) has used this XML schema for more than 5 years to accept and process submissions containing more than 1,814,139 SNPs on 20,797 subjects using 8,975 assays. Although developed in the context of pharmacogenomics, the schema is of general utility for exchange of genotype and phenotype data. We have written syntactic and semantic validators to check documents using this format. The schema and code for validation is available to the community at http://www.pharmgkb.org/schema/index.html (last accessed: 8 October 2007).

Genetic variability in the coat protein genes of two orchid viruses: Cymbidium mosaic virus and Odontoglossum ringspot virus.

The variability in coat protein gene sequences of Cymbidium mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV) that naturally infect orchids worldwide was investigated. Samples were collected from Korea, Singapore and Taiwan. The sequence data were compared with available published coat protein gene sequences of CymMV and ORSV, including those from Japan and Thailand. Among CymMV isolates, the homology was 89.1%-99.7% and 93.2%-100% at the nucleotide and amino acid levels, respectively. Among the ORSV isolates, the homology was 95.5%-100% and 93%-100% at the nucleotide and amino acid levels, respectively. No particular region of variability could be defined in either of the viruses. In deduced amino acid sequence, the N-terminal was more conserved than the C-terminal in both CymMV and ORSV. By comparing all sequences determined in this study and those that are published in the GenBank databases, we did not find clustering based on geographical distribution or sequence identity. Such high sequence conservation suggests that both CymMV and ORSV coat protein genes are suitable candidates to provide resistance to orchids cultivated in different geographical locations.

Requirement of B7-mediated costimulation in the induction of experimental autoimmune anterior uveitis.

PURPOSE: To study the role of costimulatory signaling through the CD28-B7 interaction in experimental autoimmune anterior uveitis (EAAU). METHODS: Naive Lewis rats were immunized with insoluble melanin-associated antigen (MAA) derived from bovine iris and ciliary body. CTLA4-Fc, a recombinant protein comprised of the extracellular domain of human CTLA4 bound to mouse IgG2a Fc, was used to block the CD28-B7 interaction. A mutant version (CTLA4-Fc-mutant) was used as a control. The effect of CTLA4-Fc on the in vivo induction of disease with MAA was studied. Subsequently, the mechanism by which CTLA4-Fc blocked the interaction of CD28 and B7 was investigated in vivo, using the adoptive transfer of T cells derived from CTLA4-Fc-treated rats, and in vitro, using the proliferative response and cytokine production of MAA-T cells in the presence of CTLA4-Fc. RESULTS: CTLA4-Fc markedly reduced the incidence and severity of EAAU in Lewis rats after sensitization with MAA. The adoptive transfer of sensitized T cells from CTLA4-Fc-treated donors did not induce EAAU in naive recipients. CTLA4-Fc inhibited the expansion of antigen-specific MAA-T cells and the production of TNF-alpha. CONCLUSIONS: The costimulatory signal delivered through CD28-B7 is required for the induction and pathogenesis of EAAU. In the absence of this signal, antigen-specific expansion of MAA reactive T cells as well as production of TNF-alpha is inhibited. Abrogation of this costimulatory signal may be an important therapeutic option for EAAU.

Kinetics of cytokine production in experimental autoimmune anterior uveitis (EAAU).

PURPOSE: Experimental autoimmune anterior uveitis (EAAU) can be induced in Lewis rats with bovine melanin associated antigen (MAA) extracted from the iris/ciliary body (CB) and does not require adjuvant. The present investigation was undertaken to study the expression of various cytokines in EAAU. METHODS: Lewis rats were immunized with bovine MAA and sacrificed at various time points. The iris/CB and popliteal lymph nodes were harvested, and total RNA isolated. The reverse transcription polymerase chain reaction (RT-PCR) was utilized to determine the mRNA expression of IFN-gamma, TNF-alpha, IL-2, IL-4, IL-6 and IL-10. RESULTS: TNF-alpha mRNA levels in iris/CB paralleled the course of EAAU and increased dramatically at the peak of disease. However, mRNA levels of TNF-alpha demonstrated little change in the popliteal lymph node. IFN-gamma mRNA was barely detectable in the iris/CB and increased only slightly at the peak of disease. In contrast, IFN-gamma mRNA levels in the popliteal lymph node paralleled the course of disease and increased during the peak of disease. IL-10 mRNA did not change in the iris/CB but increased modestly in the popliteal lymph node. IL-2, IL-4, and IL-6 mRNA levels did not change during the course of EAAU in either tissue. CONCLUSIONS: Our study reveals an interesting correlation between the expression of TNF-alpha, IFN-gamma and disease progression in EAAU. Furthermore, they suggest that TNF-alpha is an important cytokine in the target tissue, while IFN-gamma is in the draining lymph node.

Induction of experimental autoimmune anterior uveitis by a self-antigen: melanin complex without adjuvant.

PURPOSE: Experimental autoimmune anterior uveitis (EAAU) is an organ-specific autoimmune disease induced by immunization with bovine melanin-associated antigen (MAA) and two adjuvants (complete Freund's adjuvant and purified pertussis toxin). This study was undertaken to explore whether an adjuvant is required in the induction of EAAU. METHODS: Insoluble MAA was extracted from the bovine iris and ciliary body. Soluble bovine MAA was derived by treatment of insoluble MAA with the proteolytic enzyme, V8 protease. Lewis rats were immunized with the insoluble or soluble antigen, with or without adjuvant (complete Freund's adjuvant and purified pertussis toxin). Adoptive transfer of CD4+ and CD8+ T cells was performed to investigate the pathogenesis of EAAU. RESULTS: Experimental autoimmune anterior uveitis can be induced in Lewis rats by immunization with 100 g insoluble bovine MAA alone without the use of adjuvants. The disease can be adoptively transferred to naive syngenic rats by primed CD4+ T cells. In contrast, soluble bovine MAA was not uveitogenic unless adjuvants were employed. CONCLUSIONS: The data suggest that EAAU can be induced in the Lewis rat without addition of an adjuvant. Future studies concerning the pathogenesis of EAAU can now be performed without the possible confounding effect of an adjuvant.

Interleukin-6 and retroperitoneal fibromatosis from SRV-2-infected macaques with simian AIDS.

We investigated the role of Interleukin-6 (IL-6) as an autocrine growth factor for the retroperitoneal fibromatosis (RF) cells present in macaques infected with the simian retrovirus type 2 (SRV-2). Elevated levels of IL-6 were found in serum of SRV-2 antibody-positive macaques, ascites from RF-positive animals, and RF cell line culture media. IL-6 mRNA levels increased approximately five-fold in RF cells incubated with exogenous SRV-2. In RF cells, SRV-2 functions to increase IL-6 mRNA and protein production and presumably serves as autocrine growth factor.

Mesenchymoproliferative disorders (MPD) in simian AIDS associated with SRV-2 infection.

We have observed several mesenchymal proliferative disorders (MPD) in macaques with SAIDS associated with SRV-2 infection. Retroperitoneal and subcutaneous fibromatosis, progressive fibrovascular proliferation, mimicking Kaposi's sarcoma, were seen in 165 macaques. Three obliterative fibrointimal proliferative arteriopathies and one congenital pulmonary sequestration with extensive MPD were observed in SRV-2 positive monkeys. Continuous cell lines were established and SRV-2 was identified in all tissues and cell lines. Immunophenotyping of the cultured cells showed heterogeneous mesenchymal cells. Xenograft and allograft transplantation of cultured cells produced MPD lesions in the recipients. The data suggest that SRV-2 plays an important role in the etiopathogenesis of MPD in macaques.