Muscle Activation During Landing Before and After Fatigue in Individuals With or Without Chronic Ankle Instability

Ankle instability is a common condition in physically active individuals. It often occurs during a jump landing or lateral motion, particularly when participants are fatigued

Characterization of the Bacterial Metallothionein, PmtA in the Human Pathogen Pseudomonas aeruginosa

Small, cysteine-rich proteins called metallothioneins (MTs) bind essential divalent heavy metal cations, such as zinc and copper, as well as toxic heavy metals, such as cadmium and mercury. Stressful conditions such as exposure to heavy metals or reactive oxygen species (ROS) increase the expression of MTs. The numerous cysteine residues in MTs allow the protein to neutralize toxic effects of ROS, bind heavy metals, influence immune cell movement and proliferation. The bacteria Pseudomonas aeruginosa expresses an MT, PmtA, that is similar in structure the eukaryotic MTs. Evidence presented in these suggests that PmtA is an immunomodulatory protein, similar to the eukaryotic counterpart. Jurkat T cells pre-incubated with PmtA and subsequently exposed to a gradient of SDF-1a, lost the ability to move in a persistent direction, while Jurkat T cells pre-incubated with GST did respond to the SDF-1a gradient. Incubation with PmtA also decreased SDF-1a-induced internalization of the receptor CXCR4 on Jurkat T cells. P. aeruginosa strain PW4670 lacks PmtA expression, and is also more sensitive to oxidant exposure than the parent strain PA01. PW4670 also fails to produce pyocyanin, a secondary metabolite that produces ROS that can disrupts the immune response to P. aeruginosa. Due to the lack of pyocyanin by PW4670, PAO1 supernatant is more likely to kill macrophage cells in vitro and Galleria mellonella larvae in vivo, that PW4670 supernatant. Taken together, these results suggest that the expression of PmtA influences the virulence of P. aeruginosa, and may be a novel target for therapeutic intervention

A Microarray Biosensor for Multiplexed Detection of Microbes Using Grating-Coupled Surface Plasmon Resonance Imaging

Grating-coupled surface plasmon resonance imaging (GCSPRI) utilizes an optical diffraction grating embossed on a gold-coated sensor chip to couple collimated incident light into surface plasmons. The angle at which this coupling occurs is sensitive to the capture of analyte at the chip surface. This approach permits the use of disposable biosensor chips that can be mass-produced at low cost and spotted in microarray format to greatly increase multiplexing capabilities. The current GCSPRI instrument has the capacity to simultaneously measure binding at over 1000 unique, discrete regions of interest (ROIs) by utilizing a compact microarray of antibodies or other specific capture molecules immobilized on the sensor chip. In this report, we describe the use of GCSPRI to directly detect multiple analytes over a large dynamic range, including soluble protein toxins, bacterial cells, and viruses, in near real-time. GCSPRI was used to detect a variety of agents that would be useful for diagnostic and environmental sensing purposes, including macromolecular antigens, a nontoxic form of <i>Pseudomonas aeruginosa</i> exotoxin A (ntPE), <i>Bacillus globigii</i>, <i>Mycoplasma hyopneumoniae</i>, <i>Listeria monocytogenes</i>, <i>Escherichia coli</i>, and M13 bacteriophage. These studies indicate that GCSPRI can be used to simultaneously assess the presence of toxins and pathogens, as well as quantify specific antibodies to environmental agents, in a rapid, label-free, and highly multiplexed assay requiring nanoliter amounts of capture reagents