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

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

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

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

Whether initiation of antiretroviral therapy (ART) regimens aimed at achieving greater concentrations within gut associated lymphoid tissue (GALT) impacts the level of mucosal immune reconstitution, inflammatory markers and the viral reservoir remains unknown. We included 12 HIV- controls and 32 ART-naïve HIV patients who were randomized to efavirenz, maraviroc or maraviroc+raltegravir, each with fixed-dose tenofovir disoproxil fumarate/emtricitabine. Rectal and duodenal biopsies were obtained at baseline and at 9 months of ART. We performed a comprehensive assay of T-cell subsets by flow cytometry, T-cell density in intestinal biopsies, plasma and tissue concentrations of antiretroviral drugs by high-performance liquid chromatography/mass spectroscopy, and plasma interleukin-6 (IL-6), lipoteichoic acid (LTA), soluble CD14 (sCD14) and zonulin-1 each measured by ELISA. Total cell-associated HIV DNA was measured in PBMC and rectal and duodenal mononuclear cells. Twenty-six HIV-infected patients completed the follow-up. In the duodenum, the quadruple regimen resulted in greater CD8+ T-cell density decline, greater normalization of mucosal CCR5+CD4+ T-cells and increase of the naïve/memory CD8+ T-cell ratio, and a greater decline of sCD14 levels and duodenal HIV DNA levels (P = 0.004 and P = 0.067, respectively), with no changes in HIV RNA in plasma or tissue. Maraviroc showed the highest drug distribution to the gut tissue, and duodenal concentrations correlated well with other T-cell markers in duodenum, i.e., the CD4/CD8 ratio, %CD4+ and %CD8+ HLA-DR+CD38+ T-cells. Maraviroc use elicited greater activation of the mucosal naïve CD8+ T-cell subset, ameliorated the distribution of the CD8+ T-cell maturational subsets and induced higher improvement of zonulin-1 levels. These data suggest that combined CCR5 and integrase inhibitor based combination therapy in ART treatment naïve patients might more effectively reconstitute duodenal immunity, decrease inflammatory markers and impact on HIV persistence by cell-dependent mechanisms, and show unique effects of MVC in duodenal immunity driven by higher drug tissue penetration and possibly by class-dependent effects

Allelic variants of the NLR protein Rpi-chc1 differentially recognize members of the Phytophthora infestans PexRD12/31 effector superfamily through the leucine-rich repeat domain

Phytophthora infestans is a pathogenic oomycete that causes the infamous potato late blight disease. Resistance (R) genes from diverse Solanum species encode intracellular receptors that trigger effective defense responses upon the recognition of cognate RXLR avirulence (Avr) effector proteins. To deploy these R genes in a durable fashion in agriculture, we need to understand the mechanism of effector recognition and the way the pathogen evades recognition. In this study, we cloned 16 allelic variants of the Rpi-chc1 gene from Solanum chacoense and other Solanum species, and identified the cognate P. infestans RXLR effectors. These tools were used to study effector recognition and co-evolution. Functional and non-functional alleles of Rpi-chc1 encode coiled-coil nucleotide-binding leucine-rich repeat (CNL) proteins, being the first described representatives of the CNL16 family. These alleles have distinct patterns of RXLR effector recognition. While Rpi-chc1.1 recognized multiple PexRD12 (Avrchc1.1) proteins, Rpi-chc1.2 recognized multiple PexRD31 (Avrchc1.2) proteins, both belonging to the PexRD12/31 effector superfamily. Domain swaps between Rpi-chc1.1 and Rpi-chc1.2 revealed that overlapping subdomains in the leucine-rich repeat (LRR) domain are responsible for the difference in effector recognition. This study showed that Rpi-chc1.1 and Rpi-chc1.2 evolved to recognize distinct members of the same PexRD12/31 effector family via the LRR domain. The biased distribution of polymorphisms suggests that exchange of LRRs during host–pathogen co-evolution can lead to novel recognition specificities. These insights will guide future strategies to breed durable resistant varieties

A framework for healthcare interventions to address maternal morbidity

© 2018 World Health Organization; licensed by John Wiley & Sons Ltd on behalf of International Federation of Gynecology and Obstetrics. The maternal health agenda is undergoing a paradigm shift from preventing maternal deaths to promoting women's health and wellness. A critical focus of this trajectory includes addressing maternal morbidity and the increasing burden of chronic and noncommunicable diseases (NCD) among pregnant women. The WHO convened the Maternal Morbidity Working Group (MMWG) to improve the scientific basis for defining, measuring, and monitoring maternal morbidity. Based on the MMWG's work, we propose paradigms for conceptualizing maternal health and related interventions, and call for greater integration between maternal health and NCD programs. This integration can be synergistic, given the links between chronic conditions, morbidity in pregnancy, and long-term health. Pregnancy should be viewed as a window of opportunity into the current and future health of women, and offers critical entry points for women who may otherwise not seek or have access to care for chronic conditions. Maternal health services should move beyond the focus on emergency obstetric care, to a broader approach that encompasses preventive and early interventions, and integration with existing services. Health systems need to respond by prioritizing funding for developing integrated health programs, and workforce strengthening. The MMWG's efforts have highlighted the changing landscape of maternal health, and the need to expand the narrow focus of maternal health, moving beyond surviving to thriving

Impacts of allelopathic compounds of Prosopis juliflora present in soil on seed germination and initial seedling growth of native dry forest plants in Bundala National Park

Prosopis juliflora  is an alien exotic plant in many arid and semi-arid areas in the tropics such as Saudai Arabia, India and Sri Lanka. This species was introduced to Hambanthota district in the southern province of Sri Lanka in early 1950s to improve saline soils in the area but it has spread in to natural ecosystems in Bundala National Park and other areas having similar climatic conditions.  P. julifloraproduces water soluble alleloapathic chemicals in its leaves, roots,  pods and flowers such as L-tryptophan, Syringin and Laricriesinol. This study was conducted to determine the effects of allelopathic compounds of P. juliflora accumulated in soil on seed germination and initial seedling growth of selected native dry forest plant species:  Bauhinia racemosa, Cassia occidentalis, Drypetis sepiaria, Flueggea leucopyrus, Manilkara hexandra and Salvodora persica  by keeping seeds in soils collected from natural dry forest and  P. juliflora  stand in five replicates. The experiment  was extended further by mixing soil with activated charcoal which is capable of absorbing allopathic compounds. Impact on seed germination and initial seedling growth were evaluated by measuring seed germination and, shoot and root lengths using a wetted string. Percentage seed germination of B. racemosa, C. occidentalis, D. sepiaria, and M. hexandra and the root growth of all tested plant species were significantly reduced in soil collected from  P. juliflorastand when compared with natural dry forest soil and  P. juliflora  stand’s soil with activated charcoal. Addition of activated charcoal into natural dry forest soil did not show any significant impact on seed germination and seedling growth. Allopathic compounds dissolved in soil solution is taken up by   plant roots, these contact with the roots before reaching shoot parts and these may be the reason for high suppression of root growth than that of shoot growth of some selected plant species. These results indicate the presence of allelopathic compounds in soil collected from the  P. juliflora  stand and these allelopathic compounds may adversely effect on seed germination and initial seedling growth of some native dry forest plant species. However, there is a variation in the sensitivity to allelopathic compounds among native dry forest plant species.Key Words: Alien exotic plant, activated charcoal and natural dry forest soi

Case Reports Childhood lead poisoning

Lead is a natural element and does not break down in the environment. Once it has been disposed and deposited in the environment, it will remain and poison generations of children unless it is controlle

Exposition radiologique des personnels affectés aux opérations de maintenance de radar de surveillance aérienne

Le Service de protection radiologique des Armées (SPRA) a mené une étude afin d’évaluer l’exposition des personnels en charge de la maintenance d'un radar de type Palmier sur une base aérienne. Le but de cette étude est d’estimer les doses reçues, de mesurer les différents débits d’équivalents de dose ambiant et de définir un zonage radiologique. Au terme de deux campagnes de mesures, les doses efficaces enregistrées par des dosimètres passifs OSL Inlight® corps entier ont permis de conforter les résultats obtenus par les mesures radiamétriques. Par ailleurs, les débits d’équivalents de dose varient de façon importante en fonction de la position de l’opérateur dans la zone des émetteurs. À partir de ces résultats, les auteurs préconisent des recommandations concernant le zonage radiologique, la catégorisation et les modalités de surveillance dosimétrique des personnels