152 research outputs found

    Orbits of Second Order Linear Recurrences over Finite Fields

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    Let QQ be the matrix (ab10)\displaystyle \begin{pmatrix} a & b \\ 1 & 0 \end{pmatrix} in GL2(Fq)GL_2(\mathbb{F}_q) where Fq\mathbb{F}_q is a finite field, and let GG be the finite cyclic group generated by QQ. We consider the action of GG on the set Fq×Fq\mathbb{F}_q \times \mathbb{F}_q. In particular, we study certain relationships between the lengths of the non-trivial orbits of GG, and their frequency of occurrence. This is done in part by investigating the order of elements of a product in an abelian group when the product has prime power order. For qq a prime and b=1b=1, the orbits correspond to Fibonacci type linear recurrences modulo qq for different initial conditions. We also derive certain conditions under which the roots of the characteristic polynomial of QQ are generators of Fq×\mathbb{F}_q^\times. Examples are included to illustrate the theory.23 page

    Identification of Thioaptamer Ligand against E-Selectin: Potential Application for Inflamed Vasculature Targeting

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    Active targeting of a drug carrier to a specific target site is crucial to provide a safe and efficient delivery of therapeutics and imaging contrast agents. E-selectin expression is induced on the endothelial cell surface of vessels in response to inflammatory stimuli but is absent in the normal vessels. Thus, E-selectin is an attractive molecular target, and high affinity ligands for E-selectin could be powerful tools for the delivery of therapeutics and/or imaging agents to inflamed vessels. In this study, we identified a thiophosphate modified aptamer (thioaptamer, TA) against E-selectin (ESTA-1) by employing a two-step selection strategy: a recombinant protein-based TA binding selection from a combinatorial library followed by a cell-based TA binding selection using E-selectin expressing human microvascular endothelial cells. ESTA-1 selectively bound to E-selectin with nanomolar binding affinity (KD = 47 nM) while exhibiting minimal cross reactivity to P- and L-selectin. Furthermore, ESTA-1 binding to E-selectin on the endothelial cells markedly antagonized the adhesion (over 75% inhibition) of sLex positive HL-60 cells at nanomolar concentration. ESTA-1 also bound specifically to the inflamed tumor-associated vasculature of human carcinomas derived from breast, ovarian, and skin but not to normal organs, and this binding was highly associated with the E-selectin expression level. Similarly, intravenously injected ESTA-1 demonstrated distinct binding to the tumor vasculature in a breast cancer xenograft model. Together, our data substantiates the discovery of a thioaptamer (ESTA-1) that binds to E-selectin with high affinity and specificity, thereby highlighting the potential application of ESTA-1 for E-selectin targeted delivery

    Thioaptamer Conjugated Liposomes for Tumor Vasculature Targeting

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    Recent developments in multi-functional nanoparticles offer a great potential for targeted delivery of therapeutic compounds and imaging contrast agents to specific cell types, in turn, enhancing therapeutic effect and minimizing side effects. Despite the promise, site specific delivery carriers have not been translated into clinical reality. In this study, we have developed long circulating liposomes with the outer surface decorated with thioated oligonucleotide aptamer (thioaptamer) against E-selectin (ESTA) and evaluated the targeting efficacy and PK parameters. In vitro targeting studies using Human Umbilical Cord Vein Endothelial Cell (HUVEC) demonstrated efficient and rapid uptake of the ESTA conjugated liposomes (ESTA-lip). In vivo, the intravenous administration of ESTA-lip resulted in their accumulation at the tumor vasculature of breast tumor xenografts without shortening the circulation half-life. The study presented here represents an exemplary use of thioaptamer for targeting and opens the door to testing various combinations of thioaptamer and nanocarriers that can be constructed to target multiple cancer types and tumor components for delivery of both therapeutics and imaging agents

    Correction: Effects of Combined CCR5/Integrase Inhibitors-Based Regimen on Mucosal Immunity in HIV-Infected Patients Naïve to Antiretroviral Therapy: A Pilot Randomized Trial

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    The fifth author's name is incorrect. The correct name is Tae-Wook Chun. The correct citation is: Serrano-Villar S, Sainz T, Ma Z-M, Utay NS, Chun T-W, Mann S, et al. (2016) Effects of Combined CCR5/Integrase Inhibitors-Based Regimen on Mucosal Immunity in HIV-Infected Patients Naïve to Antiretroviral Therapy: A Pilot Randomized Trial. PLoS Pathog 12(1): e1005381. doi:10.1371/journal.ppat.1005381
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