With widespread abuse of antibiotics, bacterial resistance has increasingly become a serious threat. Acinetobacter baumannii has emerged as one of the most important hospital-acquired pathogens worldwide. Bacteriophages (also called “phages”) could be used as a potential alternative therapy to meet the challenges posed by such pathogens. Endolysins from phages have also been attracting increasing interest as potential antimicrobial agents. Here, we isolated 14 phages against A. baumannii, determined the lytic spectrum of each phage, and selected one with a relatively broad host range, named vB_AbaP_PD-6A3 (PD-6A3 for short), for its biological characteristics. We over-expressed and purified the endolysin (Ply6A3) from this phage and tested its biological characteristics. The PD-6A3 is a novel phage, which can kill 32.4% (179/552) of clinical multidrug resistant A. baumannii (MDRAB) isolates. Interestingly, in vitro, this endolysin could not only inhibit A. baumannii, but also that of other strains, such as Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA). We found that lethal A. baumannii sepsis mice could be effectively rescued in vivo by phage PD-6A3 and endolysin Ply6A3 intraperitoneal injection. These characteristics reveal the promising potential of phage PD-6A3 and endolysin Ply6A3 as attractive candidates for the control of A. baumannii-associated nosocomial infections.

Initiating as protruding ridges above and below the optic vesicle, the eyelids of mice grow across the eye and temporarily fuse in fetal life. Mutations of a number of genes disrupt this developmental process and result in a birth defect, "open-eyelids at birth." Here we show that a critical event for eyelid induction occurs at embryonic day 11.5 (E11.5) when the single cell-layered ectoderm in the presumptive eyelid territory increases proliferation and undergoes morphologic transition to form cube-shaped epithelial cells. Using embryos lacking the Fgfr2 Ig domain III (Fgfr2 ⌬III/⌬III ) generated by tetraploid rescue and chimeric embryo formation approaches, we demonstrate that this event is controlled by Fgfr2 signals as the Fgfr2 ⌬III/⌬III mutation blocks these changes and results in embryos without eyelids. Fgfr2 and its ligands are differentially expressed in the ectoderm and underlying mesenchyme and function in a reciprocal interacting loop that specifies eyelid development. We also demonstrate that similar defects account for failure of skin formation at early stages. Interestingly, Fgfr2-independent skin formation occurs at E14.5 mutant embryos, resulting in much thinner, yet well-differentiated epidermis. Notably, mutant skin remains thin with decreased hair density after transplantation to wild-type recipients. These data demonstrate an essential role of Fgfr2 in eyelid and skin formation and patterning. Published 2001 Wiley-Liss, Inc. †

In this article, we report on the process for creating microcellular and nanocellular polysulfone (PSU) foams. Microcellular foams with cell size up to 8 mm and nanocellular foams with cell size in the range of 20-30 nm were created. A range of CO 2 concentration was achieved by varying saturation temperature, from 5% at 60 C to 14.7% at 210 C. The CO 2 concentration has a strong influence on the cellular structure.There exists a critical concentration window, between 10.7% and 12.3%, within which cell nucleation densities increase rapidly and cell sizes drop from micrometer range to below 1 mm into the nanometer range. Nanofoams with cell nucleation densities exceeding 10 15 cells/cm 3 and void fraction of up to 48% are achieved. At the high CO 2 concentration region, the change from closed nanocellular structure to bicontinuous nanoporous structure is observed. Also, nanostructures on the cell wall of microcells are observed and believed to be formed via stressinduced nucleation/spinodal decomposition. The PSU nanofoams produced in this study present an opportunity to produce polymer nanofoams with a relatively high service temperature. The ability to create cells of different length scales provides an opportunity to study the effect of cell size on the foams properties.

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