pMPES: A Modular Peptide Expression System for the Delivery of Antimicrobial Peptides to the Site of Gastrointestinal Infections Using Probiotics

Antimicrobial peptides are a promising alternative to traditional antibiotics, but their utility is limited by high production costs and poor bioavailability profiles. Bacterial production and delivery of antimicrobial peptides (AMPs) directly at the site of infection may offer a path for effective therapeutic application. In this study, we have developed a vector that can be used for the production and secretion of seven antimicrobial peptides from both Escherichia coli MC1061 F’ and probiotic E.coli Nissle 1917. The vector pMPES (Modular Peptide Expression System) employs the Microcin V (MccV) secretion system and a powerful synthetic promoter to drive AMP production. Herein, we demonstrate the capacity of pMPES to produce inhibitory levels of MccV, Microcin L (MccL), Microcin N (McnN), Enterocin A (EntA), Enterocin P (EntP), Hiracin JM79 (HirJM79) and Enterocin B (EntB). To our knowledge, this is the first demonstration of such a broadly-applicable secretion system for AMP production. This type of modular expression system could expedite the development of sorely needed antimicrobial technologie

Validation of a low-cost, carbon dioxide-based cryoablation system for percutaneous tumor ablation.

Breast cancer rates are rising in low- and middle-income countries (LMICs), yet there is a lack of accessible and cost-effective treatment. As a result, the cancer burden and death rates are highest in LMICs. In an effort to meet this need, our work presents the design and feasibility of a low-cost cryoablation system using widely-available carbon dioxide as the only consumable. This system uses an 8-gauge outer-diameter needle and Joule-Thomson expansion to percutaneously necrose tissue with cryoablation. Bench top experiments characterized temperature dynamics in ultrasound gel demonstrated that isotherms greater than 2 cm were formed. Further, this system was applied to mammary tumors in an in vivo rat model and necrosis was verified by histopathology. Finally, freezing capacity under a large heat load was assessed with an in vivo porcine study, where volumes of necrosis greater than 1.5 cm in diameter confirmed by histopathology were induced in a highly perfused liver after two 7-minute freeze cycles. These results demonstrate the feasibility of a carbon-dioxide based cryoablation system for improving solid tumor treatment options in resource-constrained environments

Experimental validation of active control of low-order aberrations with a Zernike sensor through a Lyot coronagraph

International audienceFuture large segmented space telescopes and their coronagraphic instruments are expected to provide the resolution and sensitivity to observe Earth-like planets with a 1010 contrast ratio at less than 100 mas from their host star. Advanced coronagraphs and wavefront control methods will enable the generation of high-contrast dark holes in the image of an observed star. However, drifts in the optical path of the system will lead to pointing errors and other critical low-order aberrations that will prevent maintenance of this contrast. To measure and correct for these errors, we explore the use of a Zernike wavefront sensor (ZWFS) in the starlight rejected and filtered by the focal plane mask of a Lyot-type coronagraph. In our previous work, the analytical phase reconstruction formalism of the ZWFS was adapted for a filtered beam. We now explore strategies to actively compensate for these drifts in a segmented pupil setup on the High-contrast imager for Complex Aperture Telescopes (HiCAT). This contribution presents laboratory results from closed-loop compensation of bench internal turbulence as well as known introduced aberrations using phase conjugation and interaction matrix approaches. We also study the contrast recovery in the image plane dark hole when using a closed loop based on the ZWFS

High-contrast imager for complex aperture telescopes (HiCAT): 6. Two deformable mirror wavefront control (Conference Presentation)

The goal of the High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed is to demonstrate coronagraphic starlight suppression solutions for future segmented aperture space telescopes such as the Large UV, Optical, IR telescope (LUVOIR) mission concept being studied by NASA. The testbed design has the flexibility to enable studies with increasing complexity for telescope aperture geometries starting with off-axis telescopes, then on-axis telescopes with central obstruction and support structures. The testbed implements the Apodized Pupil Lyot Coronagraph (APLC) optimized for the HiCAT aperture, which is similar to one of the possible geometries considered for LUVOIR. Wavefront can be controlled using continuous deformable mirrors, and wavefront sensing is performed using the imaging camera, or a dedicated phase retrieval camera, and also in a low-order wavefront sensing arm. We present a progress update of the testbed in particular results using two deformable mirror control to produce high-contrast dark zone, and preliminary results using the testbed’s low order Zernike wavefront sensor

High-contrast imager for complex aperture telescopes (HiCAT): 6. Two deformable mirror wavefront control (Conference Presentation)

The goal of the High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed is to demonstrate coronagraphic starlight suppression solutions for future segmented aperture space telescopes such as the Large UV, Optical, IR telescope (LUVOIR) mission concept being studied by NASA. The testbed design has the flexibility to enable studies with increasing complexity for telescope aperture geometries starting with off-axis telescopes, then on-axis telescopes with central obstruction and support structures. The testbed implements the Apodized Pupil Lyot Coronagraph (APLC) optimized for the HiCAT aperture, which is similar to one of the possible geometries considered for LUVOIR. Wavefront can be controlled using continuous deformable mirrors, and wavefront sensing is performed using the imaging camera, or a dedicated phase retrieval camera, and also in a low-order wavefront sensing arm. We present a progress update of the testbed in particular results using two deformable mirror control to produce high-contrast dark zone, and preliminary results using the testbed’s low order Zernike wavefront sensor

A Case Study of the Neti Pot’s Rise, Americanization, and Rupture as Integrative Medicine in U.S. Media Discourse

This is an Accepted Manuscript of an article published by Taylor & Francis in Health Communication on 16 Feb 2016, available online: http://dx.doi.org/10.1080/10410236.2015.1047145In a period of only one decade in the United States, the neti pot shifted from obscure Ayurvedic health device to mainstream complementary and integrative medicine (CIM), touted by celebrities and sold widely in drug stores. We examine the neti pot as a case study for understanding how a foreign health practice became mainstreamed, and what that process reveals about more general discourses of health in the United States. Using discourse analysis of U.S. popular press and new media news (1999–2012) about the neti pot, we trace the development of discourses from neti’s first introduction in mainstream news, through the hype following Dr. Oz’s presentation on Oprah, to 2011 when two adults tragically died after using Naegleria fowleri amoeba-infested tap water in their neti pots. Neti pot discourses are an important site for communicative analysis because of the pot’s complexity as an intercultural artifact: Neti pots and their use are enfolded into the biomedical practice of nasal irrigation and simultaneously Orientalized as exotic/magical and suspect/dangerous. This dual positioning as normal and exotic creates inequitable access for using the neti pot as a resource for increasing cultural health capital (CHC). This article contributes to work that critically theorizes the transnationalism of CIM, as the neti pot became successfully Americanized. These results have implications for understanding global health practices’ incorporation or co-optation in new contexts, and the important role that popularly mediated health communication can play in framing what health care products and practices mean for consumers