Biomagnetism and Ferritin Final Report

Methods for determining iron content in frog embryos and ferritin in rat intestine section

Cellulose acetate phthalate, a common pharmaceutical excipient, inactivates HIV-1 and blocks the coreceptor binding site on the virus envelope glycoprotein gp120

BACKGROUND: Cellulose acetate phthalate (CAP), a pharmaceutical excipient used for enteric film coating of capsules and tablets, was shown to inhibit infection by the human immunodeficiency virus type 1 (HIV-1) and several herpesviruses. CAP formulations inactivated HIV-1, herpesvirus types 1 (HSV-1) and 2 (HSV-2) and the major nonviral sexually transmitted disease (STD) pathogens and were effective in animal models for vaginal infection by HSV-2 and simian immunodeficiency virus. METHODS: Enzyme-linked immunoassays and flow cytometry were used to demonstrate CAP binding to HIV-1 and to define the binding site on the virus envelope. RESULTS: 1) CAP binds to HIV-1 virus particles and to the envelope glycoprotein gp120; 2) this leads to blockade of the gp120 V3 loop and other gp120 sites resulting in diminished reactivity with HIV-1 coreceptors CXCR4 and CCR5; 3) CAP binding to HIV-1 virions impairs their infectivity; 4) these findings apply to both HIV-1 IIIB, an X4 virus, and HIV-1 BaL, an R5 virus. CONCLUSIONS: These results provide support for consideration of CAP as a topical microbicide of choice for prevention of STDs, including HIV-1 infection

Anti-HIV-1 activity of cellulose acetate phthalate: Synergy with soluble CD4 and induction of "dead-end" gp41 six-helix bundles

BACKGROUND: Cellulose acetate phthalate (CAP), a promising candidate microbicide for prevention of sexual transmission of the human immunodeficiency virus type 1 (HIV-1) and other sexually transmitted disease (STD) pathogens, was shown to inactivate HIV-1 and to block the coreceptor binding site on the virus envelope glycoprotein gp120. It did not interfere with virus binding to CD4. Since CD4 is the primary cellular receptor for HIV-1, it was of interest to study CAP binding to HIV-1 complexes with soluble CD4 (sCD4) and its consequences, including changes in the conformation of the envelope glycoprotein gp41 within virus particles. METHODS: Enzyme-linked immunosorbent assays (ELISA) were used to study CAP binding to HIV-1-sCD4 complexes and to detect gp41 six-helix bundles accessible on virus particles using antibodies specific for the α-helical core domain of gp41. RESULTS: 1) Pretreatment of HIV-1 with sCD4 augments subsequent binding of CAP; 2) there is synergism between CAP and sCD4 for inhibition of HIV-1 infection; 3) treatment of HIV-1 with CAP induced the formation of gp41 six-helix bundles. CONCLUSIONS: CAP and sCD4 bind to distinct sites on HIV-1 IIIB and BaL virions and their simultaneous binding has profound effects on virus structure and infectivity. The formation of gp41 six-helical bundles, induced by CAP, is known to render the virus incompetent for fusion with target cells thus preventing infection

State Intervention and Foreign Direct Investment in South Korea

SUMMARY Radical claims that foreign direct investment has ‘denationalised’ the South Korean economy are unfounded; and neoclassical claims that Korean policy towards direct foreign investment has been unusually liberal are equally untrue. This article argues that the positive effect of foreign direct investment on Korea's development is due in important part to the government's directive, ‘illiberal’ policies toward foreign investment. RESUMEN Intervención estatal e inversión extranjera directa en Corea del Sur Este articulo plantea que son infundados tanto los planteamientos radicales sobre la desnacionalización originada por la inversión extranjera directa, como los neoclásicos relativos a que la política gubernamental ha sido anormalmente liberal con ésta. Sostiene, en cambio, que el efecto positivo de la inversión extranjera directa sobre el desarrollo de Corea del Sur, se debe en una medida considerable a la implementación gubernamental de políticas iliberales’ hacia la inversión extranjera. RESUMES L'intervention de l'état et l'investissement direct étranger en Corée du Sud Les revendications radicales que l'investissment direct étranger aurait de?nationalisé l'économie de Corée du Sud ne sont pas fondées: et les revendications néo?classiques selon lesquelles la politique Coréenne envers l'investissement direct étranger aurait été particulièrement libérale n'ont également aucun fondement. Cet article dispute les faits que l'effet positif de l'investissement direct étranger est dû en grande partie à la fonction directrice gouvernementale, une politique peu libérale envers l'investissment étranger

A Model for the Thermodynamics of Globular Proteins

Comments: 6 pages RevTeX, 6 Postscript figures. We review a statistical mechanics treatment of the stability of globular proteins based on a simple model Hamiltonian taking into account protein self interactions and protein-water interactions. The model contains both hot and cold folding transitions. In addition it predicts a critical point at a given temperature and chemical potential of the surrounding water. The universality class of this critical point is new

Expression in Escherichia coli of a cloned DNA sequence encoding the pre-S2 region of hepatitis B virus

A DNA sequence encoding the entire pre-S2 region (amino acids 120-174; serotype ayw) of human hepatitis B virus envelope protein has been inserted into the lacZ gene of the plasmid pSKS105 yielding a recombinant, pWS3. Lac+ colonies of the Escherichia coli M182 (lacIOPZYA), isolated after transformation with pWS3, produced a pre-S2 peptide-ß-galactosidase fusion protein. This fusion protein, which comprised as much as 3% of the total bacterial protein, was purified to >90% homogeneity by affinity chromatography on p-aminophenyl-ß-D-thiogalactoside-Sepharose. It is immunoprecipitable with rabbit antibodies to a synthetic peptide corresponding to amino acids 120-145 of the pre-S2 region of serotype adw [pre-S(120-145)] or with antibodies to hepatitis B virus. pre-S(120-145) completely blocked the binding of either antibody to the pre-S2 peptide-ß-galactosidase fusion protein. These results indicate that there are antigenic determinants on the fusion protein that are closely related to, if not identical to, determinants on synthetic pre-S(120-145) and on pre-S2 sequences of native hepatitis B virus particles. Thus, bacteria transformed with pWS3 can provide an abundant source of pre-S2-ß-galactosidase fusion protein, which may prove useful either as a diagnostic reagent possessing marker enzyme activity suitable for ELISA tests or as an immunogen with potential to contribute to active prophylaxis of hepatitis B

Review article: newer optical and digital chromoendoscopy techniques vs. dye-based chromoendoscopy for diagnosis and surveillance in inflammatory bowel disease

BackgroundRecent innovations in gastrointestinal endoscopy have changed our traditional approach to diagnosis and therapy in patients with inflammatory bowel diseases (IBD). While traditionally used dye-based chromoendoscopy (DBC) techniques suffer from several limitations that reduce their utility in daily routine practice, newer dye-less' chromoendoscopy (DLC) techniques offer a great potential to overcome most of these limitations. AimTo review available optical and digital chromoendoscopy techniques, by critically discussing their potential for diagnostic and surveillance colonoscopy in patients with IBD. MethodsA literature search on the use of dye-less and dye-based chromoendoscopy in IBD patients was performed. ResultsIn long-standing IBD, DBC improves detection of dysplasia (diagnostic odds ratio=17.5, 95% CI=1.2-247.1) as well as prediction of inflammatory disease activity and extent of disease compared with standard video-colonoscopy. Narrow band imaging (NBI) shows no improvement in dysplasia detection rates compared with white-light endoscopy and DBC (P=0.6). Moreover, NBI results in a suboptimal differentiation of dysplastic from nondysplastic lesions. No data regarding digital DLC techniques (i.e. FICE, i-scan) for dysplasia detection in IBD are yet available. Both NBI and i-scan are superior to white-light endoscopy in assessing the activity and extent of colorectal IBD. ConclusionsAlthough the potential benefits of newer optical and digital dye-less chromoendoscopy techniques over traditionally used DBC are substantial, only DBC can currently be recommended to improve dysplasia detection in long-standing IBD. In contrast, DLC has the potential to quantify disease activity and mucosal healing in IBD