155 research outputs found

    Cytotoxic T lymphocytes: Sniping cancer stem cells

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    Cancer stem cells (CSCs)/cancer-initiating cells (CICs) are characterized as a small population of cancer cells that have high tumor-initiating ability. CSCs/CICs are resistant to several cancer therapies, and eradication of CSCs/CICs is essential to cure cancer. How can we eradicate CSCs/CICs? Cytotoxic T lymphocytes (CTLs) might be a promising answer

    Attempt of numerical design recognition of space structure to use possession energy theory of space frame - shell and spatial structures -

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    p. 742-753In this 21st century, we are faced with the issue how we use materials of the earth ecologically. We, researchers, designers and engineers in architectural circles, always run after the possibilities of architectures that composed of limited materials of the earth. However, some architects are often put an emphasis on their artistic designs. That causes un-ecological structures. In this report, I try to judge an artistic realization numerically by the method of potential structural energy which uses a function and a diagram. This method can lead you to realize that structure is easy on the environment showed on a diagram given by analysing and reviewing a proper performance of a structure numerically based on "potential structural energy".Imagawa, N.; Suematsu, S.; Inoda, D.; Yamamoto, N. (2009). Attempt of numerical design recognition of space structure to use possession energy theory of space frame - shell and spatial structures -. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/673

    Single-gene speciation with pleiotropy: effects of allele dominance population size and delayed inheritance

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    Single-gene speciation is considered to be unlikely, but an excellent example is found in land snails, in which a gene for left-right reversal has given rise to new species multiple times. This reversal might be facilitated by their small population sizes and maternal effect (i.e., "delayed inheritance", in which an individual.s phenotype is determined by the genotype of its mother). Recent evidence suggests that a pleiotropic effect of the speciation gene on anti-predator survival may also promote speciation. Here we theoretically demonstrate that, without a pleiotropic effect, in small populations the fixation probability of a recessive mutant is higher than a dominant mutant, but they are identical for large populations and sufficiently weak selection. With a pleiotropic effect that increases mutant viability, a dominant mutant has a higher fixation probability if the strength of viability selection is sufficiently greater than that of reproductive isolation, whereas a recessive mutant has a higher fixation probability otherwise. Delayed inheritance increases the fixation probability of a mutant if viability selection is weaker than reproductive isolation. Our results clarify the conflicting effects of viability selection and positive frequency-dependent selection due to reproductive isolation and provide a new perspective to single-gene speciation theory

    Direct application of plasmid DNA containing type I interferon transgenes to vaginal mucosa inhibits HSV-2 mediated mortality

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    The application of naked DNA containing type I interferon (IFN) transgenes is a promising potential therapeutic approach for controlling chronic viral infections. Herein, we detail the application of this approach that has been extensively used to restrain ocular HSV-1 infection, for antagonizing vaginal HSV-2 infection. We show that application of IFN-α1, -α5, and –β transgenes to vaginal mouse lumen 24 hours prior to HSV-2 infection reduces HSV-2 mediated mortality by 2.5 to 3-fold. However, other type I IFN transgenes (IFN- α4, -α5, -α6, and –α9) are non effectual against HSV-2. We further show that the efficacy of IFN-α1 transgene treatment is independent of CD4+ T lymphocytes. However, in mice depleted of CD8+ T lymphocytes, the ability of IFN-α1 transgene treatment to antagonize HSV-2 was lost

    Electrospun PLLA Nanofiber Scaffolds and Their Use in Combination with BMP-2 for Reconstruction of Bone Defects

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    Introduction Adequate migration and differentiation of mesenchymal stem cells is essential for regeneration of large bone defects. To achieve this, modern graft materials are becoming increasingly important. Among them, electrospun nanofiber scaffolds are a promising approach, because of their high physical porosity and potential to mimic the extracellular matrix (ECM). Materials and Methods The objective of the present study was to examine the impact of electrospun PLLA nanofiber scaffolds on bone formation in vivo, using a critical size rat calvarial defect model. In addition we analyzed whether direct incorporation of bone morphogenetic protein 2 (BMP-2) into nanofibers could enhance the osteoinductivity of the scaffolds. Two critical size calvarial defects (5 mm) were created in the parietal bones of adult male Sprague-Dawley rats. Defects were either (1) left unfilled, or treated with (2) bovine spongiosa, (3) PLLA scaffolds alone or (4) PLLA/BMP-2 scaffolds. Cranial CT-scans were taken at fixed intervals in vivo. Specimens obtained after euthanasia were processed for histology, histomorphometry and immunostaining (Osteocalcin, BMP-2 and Smad5). Results PLLA scaffolds were well colonized with cells after implantation, but only showed marginal ossification. PLLA/BMP-2 scaffolds showed much better bone regeneration and several ossification foci were observed throughout the defect. PLLA/BMP-2 scaffolds also stimulated significantly faster bone regeneration during the first eight weeks compared to bovine spongiosa. However, no significant differences between these two scaffolds could be observed after twelve weeks. Expression of osteogenic marker proteins in PLLA/BMP-2 scaffolds continuously increased throughout the observation period. After twelve weeks osteocalcin, BMP-2 and Smad5 were all significantly higher in the PLLA/BMP-2 group than in all other groups. Conclusion Electrospun PLLA nanofibers facilitate colonization of bone defects, while their use in combination with BMP-2 also increases bone regeneration in vivo and thus combines osteoconductivity of the scaffold with the ability to maintain an adequate osteogenic stimulus
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