0.01% Hypochlorous Acid as an Alternative Skin Antiseptic: An In Vitro Comparison.

OBJECTIVE: Compare the in vitro efficacy of hypochlorous acid 0.01% (HA), povidone iodine 5% (PI), chlorhexidine gluconate 4% (CHG), and isopropyl alcohol 70% (IPA) against common skin microorganisms. MATERIALS AND METHODS: Time-kill studies were conducted against methicillin-susceptible Staphylococcus aureus (MSSA) and Staphylococcus epidermidis (MSSE), methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE), Candida albicans, Corynebacterium species (striatum and amycolatum), Propionibacterium acnes, Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus capitis, and Staphylococcus xylosus. RESULTS: Methicillin-resistant S. aureus: Bactericidal effect was immediate for HA and IPA. For PI and CHG, the effect occurred at 1 and 10 minutes, respectively. Methicillin-resistant S. epidermidis: Hypochlorous acid, IPA, and PI had immediate bactericidal effects, whereas CHG required 1 minute. Methicillin-susceptible Staphylococcus aureus: All agents had bactericidal effects at 1 minute. C. species, S. pyogenes, P. aeruginosa, and P. acnes: All antiseptics demonstrated immediate bactericidal effects. Methicillin-susceptible Staphylococcus epidermidis and S. capitis: Hypochlorous acid and IPA had immediate effect, whereas PI and CHG required 1 minute. C. albicans: Hypochlorous acid, IPA, and PI were immediately bactericidal, whereas CHG required 1 minute. S. xylosus: Hypochlorous acid and CHG were immediately bactericidal, whereas IPA and PI required 1 and 2 minutes, respectively. CONCLUSION: In vitro studies of HA 0.01% were observed to have equal or more efficacious antiseptic properties compared with IPA, CHG, and PI. Future studies will be needed to investigate its role in periocular use.

An enhanced bioluminescence-based Annexin V probe for apoptosis detection in vitro and in vivo.

The process of controlled cellular death known as apoptosis has an important central role not only in normal homeostatic maintenance of tissues, but also in numerous diseases such as cancer, neurodegenerative, autoimmune, and cardiovascular diseases. As a result, new technologies with the capability to selectively detect apoptotic cells represent a central focus of research for the study of these conditions. We have developed a new biosensor for the detection of apoptotic cells, incorporating the targeted selectivity for apoptotic cells from Annexin V with the sensitivity of bioluminescence signal generation from a serum-stable mutant of Renilla luciferase (RLuc8). Our data presents a complete characterization of the structural and biochemical properties of this new Annexin-Renilla fusion protein (ArFP) construct, as well as a validation of its ability to detect apoptosis in vitro. Moreover, this work represents the first report of a bioluminescent Annexin V apoptosis sensor utilized in vivo. With this new construct, we examine apoptosis within disease-relevant animal models of surgery-induced ischemia/reperfusion, corneal injury, and retinal cell death as a model of age-related macular degeneration. In each of these experiments, we demonstrate successful application of the ArFP construct for detection and bioluminescence imaging of apoptosis within each disease or treatment model. ArFP represents an important new tool in the continuously growing kit of technologies for apoptosis detection, and our results from both in vitro and in vivo experiments suggest a diverse range of potential clinically relevant applications including cancer therapeutic screening and efficacy analysis, atherosclerosis and cardiovascular disease detection, and the monitoring of any number of other conditions in which apoptosis has a central role.

Expression of a soluble truncated Vargula luciferase in Escherichia coli.

Marine luciferases are regularly employed as useful reporter molecules across a range of various applications. However, attempts to transition expression from their native eukaryotic environment into a more economical prokaryotic, i.e. bacterial, expression system often presents several challenges. Specifically, bacterial protein expression inherently lacks chaperone proteins to aid in the folding process, while Escherichia coli presents a reducing cytoplasmic environment in. These conditions contribute to the inhibition of proper folding of cysteine-rich proteins, leading to incorrect tertiary structure and ultimately inactive and potentially insoluble protein. Vargula luciferase (Vluc) is a cysteine-rich marine luciferase that exhibits glow-type bioluminescence through a reaction between its unique native substrate and molecular oxygen. Because most other commonly used bioluminescent proteins exhibit flash-type emission kinetics, this emission characteristic of Vluc is desirable for high-throughput applications where stability of emission is required for the duration of data collection. A truncated form of Vluc that retains considerable bioluminescence activity (55%) compared to the native full-length protein has been reported in the literature. However, expression and purification of this luciferase from bacterial systems has proven difficult. Herein, we demonstrate the expression and purification of a truncated form of Vluc from E. coli. This truncated Vluc (tVluc) was subsequently characterized in terms of both its biophysical and bioluminescence properties.

The Aging Risk and Atherosclerosis: A Fresh Look at Arterial Homeostasis.

A considerable volume of research over the last decade has focused on understanding the fundamental mechanisms for the progression of atherosclerosis-the underlying cause for the vast majority of all cardiovascular (CVD)-related complications. Aging is the dominant risk factor for clinically significant atherosclerotic lesion formation, yet the heightened impact of aging on the disease is not accounted for by changes in traditional risk factors, such as lack of physical activity, smoking, hypertension, hyperlipidemia, or diabetes mellitus. This review will examine the pathological and biochemical processes of atherosclerotic plaque formation and growth, with particular focus on the aging risk vis-a-vis arterial homeostasis. Particular focus will be placed on the impact of a number of important contributors to arterial homeostasis including bone marrow (BM)-derived vascular progenitor cells, differential monocyte subpopulations, and the role of cellular senescence. Finally, this review will explore many critical observations in the way the disease process has been reassessed both by clinicians and researchers, and will highlight recent advances in this field that have provided a greater understanding of this aging-driven disease.

Adaptation to Stressors by Systemic Protein Amyloidogenesis.

The amyloid state of protein organization is typically associated with debilitating human neuropathies and is seldom observed in physiology. Here, we uncover a systemic program that leverages the amyloidogenic propensity of proteins to regulate cell adaptation to stressors. On stimulus, cells assemble the amyloid bodies (A-bodies), nuclear foci containing heterogeneous proteins with amyloid-like biophysical properties. A discrete peptidic sequence, termed the amyloid-converting motif (ACM), is capable of targeting proteins to the A-bodies by interacting with ribosomal intergenic noncoding RNA (rIGSRNA). The pathological ß-amyloid peptide, involved in Alzheimer's disease, displays ACM-like activity and undergoes stimuli-mediated amyloidogenesis in vivo. Upon signal termination, elements of the heat-shock chaperone pathway disaggregate the A-bodies. Physiological amyloidogenesis enables cells to store large quantities of proteins and enter a dormant state in response to stressors. We suggest that cells have evolved a post-translational pathway that rapidly and reversibly converts native-fold proteins to an amyloid-like solid phase.