Publications by authors named "DJ Guerin"

Human immunodeficiency virus type 1 (HIV-1) infection remains a major public health threat due to its incurable nature and the lack of a highly efficacious vaccine. The RV144 vaccine trial is the only clinical study to date that demonstrated significant but modest decrease in HIV infection risk. To improve HIV-1 vaccine immunogenicity and efficacy, we recently evaluated pox-protein vaccination using a next generation liposome-based adjuvant, Army Liposomal Formulation adsorbed to aluminum (ALFA), in rhesus monkeys and observed 90% efficacy against limiting dose mucosal SHIV challenge in male animals.

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The ability to regrow lost or damaged tissues is widespread, but highly variable among animals. Understanding this variation remains a challenge in regeneration biology. Numerous studies from to mouse have shown that apoptosis acts as a potent and necessary mechanism in regeneration.

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The efficient generation and maintenance of retinal progenitor cells (RPCs) are key goals needed for developing strategies for productive eye repair. Although vertebrate eye development and retinogenesis are well characterized, the mechanisms that can initiate RPC proliferation following injury-induced regrowth and repair remain unknown. This is partly because endogenous RPC proliferation typically occurs during embryogenesis while studies of retinal regeneration have largely utilized adult (or mature) models.

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A longstanding challenge in regeneration biology is to understand the role of developmental mechanisms in restoring lost or damaged tissues and organs. As these body structures were built during embryogenesis, it is not surprising that a number of developmental mechanisms are also active during regeneration. However, it remains unclear whether developmental mechanisms act similarly or differently during regeneration as compared to development.

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Maternal smoking during pregnancy (MSDP) has detrimental effects on fetal development and on the health of the offspring into adulthood. Energy homeostasis through ATP production via the mitochondria (mt) plays a key role during pregnancy. This study aimed to determine if MSDP resulted in differences in DNA methylation to the placental mitochondrial chromosome at the transcription and replication control region, the D-Loop, and if these differences were also present in an alternate neonatal tissue (foreskin) in an independent birth cohort.

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The conversion of cytosine to 5-methylcystosine (5mC) is an important regulator of gene expression. 5mC may be enzymatically converted to 5-hydroxymethylcytosine (5hmC), with a potentially distinct regulatory function. We sought to investigate these cytosine modifications and their effect on gene expression by parallel processing of genomic DNA using bisulfite and oxidative bisulfite conversion in conjunction with RNA sequencing.

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Aim: To determine associations between methylation of NR3C1, HSD11B2, FKBP5 and ADCYAP1R1 and newborn neurobehavioral outcomes.

Methods: In 537 newborns, placental methylation was quantified using bisulfite pyrosequencing. Profiles of neurobehavior were derived via the Neonatal Intensive Care Unit Network Neurobehavioral Scales.

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Genomic imprinting disorders often exhibit delayed neurobehavioral development, suggesting this unique mechanism of epigenetic regulation plays a role in mental and neurological health. While major errors in imprinting have been linked to adverse health outcomes, there has been little research conducted on how moderate variability in imprinted gene expression within a population contributes to differences in neurobehavioral outcomes, particularly at birth. Here, we profiled the expression of 108 known and putative imprinted genes in human placenta samples from 615 infants assessed by the Neonatal Intensive Care Unit (NICU) Network Neurobehavioral Scales (NNNS).

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Maternal stress has been linked to infant birth weight outcomes, which itself may be associated with health later in life. The placenta acts as a master regulator for the fetal environment, mediating intrauterine exposures to stress through the activity of genes regulating glucocorticoids, including the 11beta-hydroxysteroid dehydrogenase (HSD11B) type 1 and 2 genes, and so we hypothesized that variation in these genes will be associated with infant birth weight. We investigated DNA methylation levels at six sites across the two genes, as well as mRNA expression for each, and the relationship to infant birth weight.

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This report documents the first example of a specific inhibitor of protein kinases with preferential binding to the activated kinase conformation: 5H-benzo[4,5]cyclohepta[1,2-b]pyridin-5-one 11r (MK-8033), a dual c-Met/Ron inhibitor under investigation as a treatment for cancer. The design of 11r was based on the desire to reduce time-dependent inhibition of CYP3A4 (TDI) by members of this structural class. A novel two-step protocol for the synthesis of benzylic sulfonamides was developed to access 11r and analogues.

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c-Met is a transmembrane tyrosine kinase that mediates activation of several signaling pathways implicated in aggressive cancer phenotypes. In recent years, research into this area has highlighted c-Met as an attractive cancer drug target, triggering a number of approaches to disrupt aberrant c-Met signaling. Screening efforts identified a unique class of 5H-benzo[4,5]cyclohepta[1,2-b]pyridin-5-one kinase inhibitors, exemplified by 1.

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The receptor tyrosine kinase c-Met is implicated in oncogenesis and is the target for several small molecule and biologic agents in clinical trials for the treatment of cancer. Binding of the hepatocyte growth factor to the cell surface receptor of c-Met induces activation via autophosphorylation of the kinase domain. Here we describe the structural basis of c-Met activation upon autophosphorylation and the selective small molecule inhibiton of autophosphorylated c-Met.

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A family of beta-substituted histidine-containing peptides has been synthesized to probe the effect of noncovalent conformational rigidification on catalyst enantioselectivity. Unambiguous enhancement of enantioselectivity in the conjugate addition of azide to alpha,beta-unsaturated carboxylate derivatives has been achieved, enabling application to a sequential asymmetric azidation/cycloaddition for the synthesis of optically enriched triazoles and triazolines.

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[formula: see text] A new protocol for the beta-azidation of alpha,beta-unsaturated carbonyl compounds is described. The method employs tertiary amines as catalysts for azide addition. The azide source is a 1:1 mixture of TMSN3 and AcOH.

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[formula: see text] Small peptides 1 and 2, which differ only in that 1 possesses a BOC-Phe residue at the N-terminus, where 2 bears a BOC-(tau-benzyl)His, were found to exhibit very different structures. In both the solid state (X-ray) and in solution (NMR and IR), peptide 1 exists as a beta-turn, whereas peptide 2 exists in a conformation that resembles the Asx-Pro motif.

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5-(o-Benzyloxy)benzylbarbituric acid (6) and 5-(p-benzyloxy)benzylbarbituric acid (7) were prepared and their inhibitory activities compared to 5-(m-benzyloxy)-benzylbarbituric acid (BBB) a known, potent inhibitor of uridine phosphorylase (UrdPase). Compounds 6 and 7 were 18-fold and 51-fold less active, respectively, than BBB in inhibiting UrdPase. These data provide solid evidence that the 5-benzylbarbituric acids possessing meta substituents are the most active inhibitors.

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