Real-Time Monitoring of Nitric Oxide Dynamics in the Myocardium: Biomedical Application of Nitric Oxide Sensor

Nitric oxide (NO) is an important physiological mediator that regulates a wide range of cellular processes in many tissues. Therefore, the accurate and reliable measurement of physiological NO concentration is essential to the understanding of NO signaling and its biological role. Most methods used for NO detection are indirect including spectroscopic approaches such as the Griess assay for nitrite and detection of methemoglobin after NO reaction with oxyhemoglobin. These methods cannot accurately reflect the changes in NO concentration in vivo and in real time. Therefore, direct methods are necessary for investigating biological process and diseases related to NO in biological conditions. There is a growing interest in the development of electrochemically based sensors for direct, in vivo, and real-time monitoring of NO. Electrochemical methods offer simplicity, good sensitivity, high selectivity, fast response times, and long-term calibration stability compared to other techniques including electron paramagnetic resonance, chemiluminescence, and fluorescence. In this article, we present real-time NO dynamics in the myocardium during myocardial ischemia-reperfusion (IR) utilizing electrochemical NO microsensor. And applications of electrochemical NO sensor for the evaluation of cardioprotective effects of therapeutic treatments such as drug administration and ischemic preconditioning are reviewed

Real-Time Detection of Nitric Oxide Release in Live Cells Utilizing Fluorinated Xerogel-Derived Nitric Oxide Sensor

Nitric oxide (NO) is an important signaling molecule that regulates a diverse range of physiological and cellular processes in many tissues. Therefore, the accurate detection of physiological NO concentration is crucial to the understanding of NO signaling and its biological role. There has been growing interest in the development of electrochemical sensors for direct and real-time monitoring of NO. As the direct electrooxidation of NO requires a relatively high working potential, further surface modification with permselective membranes is required to achieve the desired selectivity for NO via size exclusion or electrostatic repulsion. Here we reported a planar-type NO sensor with a fluorinated xerogel-derived gas permeable membrane for real-time detection of NO release in live cells. First, we evaluated the biocompatibility of xerogel-derived NO permeable membranes modified with fluorinated functional groups by growing RAW 264.7 macrophages on them. And we performed the AFM measurements to examine the morphology of RAW 264.7 macrophages on xerogel membrane. Finally, we successfully detected NO release in RAW 264.7 macrophages, using a planar-type xerogel-derived NO sensor. As a result, fluorinated xerogel-derived membrane could be utilized as both NO permeable and cell-adhesive membranes. Besides, planar-type xerogel-based NO sensors can be easily applied to the cellular sensing system, with a simple coating procedure

A Simple and Facile Glucose Biosensor Based on Prussian Blue Modified Graphite String

This work describes the string sensor for the simple and sensitive detection of glucose which is based on Prussian blue (PB) modified graphite utilizing dipping. First, PB modified graphite (PB-G) strings are characterized by physical and electrochemical techniques to optimize the PB-G layer thickness. Then, glucose oxidase (GOx) is immobilized on PB-G string electrode with biocompatible chitosan overlayer (Chi/GOx/PB-G). The Chi/GOx/PB-G string electrode exhibits a sensitivity of 641.3 μA·mM−1·cm−2 to glucose with a linear range of 0.03 to 1.0 mM (R2=0.9957) and a rapid response time (<3 s). Moreover, the Chi/GOx/PB-G string electrodes are less sensitive to common interference materials such as ascorbic acid, uric acid, galactose, and acetaminophen than to glucose. The Chi/GOx/PB-G string electrodes also show excellent reproducibility (<5% RSD). Therefore, our Chi/GOx/PB-G string electrodes can be simple, robust, and reliable tools for glucose sensing which can avoid complicated and difficult multistep fabrication processes. In addition, we expect that they have many potential applications in fields ranging from health care to food analysis, in particular where single use is favorable

Angiolipoma of the Posterior Mediastinum with Extension into the Spinal Canal: A Case Report

Angiolipoma is a rare benign soft tissue tumor, an unusual variant of lipoma, consisting of fatty and vascular components and located in the subcutis, usually in the trunk and extremities. We report a case of posterior mediastinal angiolipoma extending into the spinal canal and showing both fat and angiomatous features on CT scan

Possible Role of Horizontal Gene Transfer in the Colonization of Sea Ice by Algae

Diatoms and other algae not only survive, but thrive in sea ice. Among sea ice diatoms, all species examined so far produce ice-binding proteins (IBPs), whereas no such proteins are found in non-ice-associated diatoms, which strongly suggests that IBPs are essential for survival in ice. The restricted occurrence also raises the question of how the IBP genes were acquired. Proteins with similar sequences and ice-binding activities are produced by ice-associated bacteria, and so it has previously been speculated that the genes were acquired by horizontal transfer (HGT) from bacteria. Here we report several new IBP sequences from three types of ice algae, which together with previously determined sequences reveal a phylogeny that is completely incongruent with algal phylogeny, and that can be most easily explained by HGT. HGT is also supported by the finding that the closest matches to the algal IBP genes are all bacterial genes and that the algal IBP genes lack introns. We also describe a highly freeze-tolerant bacterium from the bottom layer of Antarctic sea ice that produces an IBP with 47% amino acid identity to a diatom IBP from the same layer, demonstrating at least an opportunity for gene transfer. Together, these results suggest that the success of diatoms and other algae in sea ice can be at least partly attributed to their acquisition of prokaryotic IBP genes

SpiroESTdb: a transcriptome database and online tool for sparganum expressed sequences tags

<p>Abstract</p> <p>Background</p> <p>Sparganum (plerocercoid of <it>Spirometra erinacei</it>) is a parasite that possesses the remarkable ability to survive by successfully modifying its physiology and morphology to suit various hosts and can be found in various tissues, even the nervous system. However, surprisingly little is known about the molecular function of genes that are expressed during the course of the parasite life cycle. To begin to decipher the molecular processes underlying gene function, we constructed a database of expressed sequence tags (ESTs) generated from sparganum.</p> <p>Findings</p> <p>SpiroESTdb is a web-based information resource that is built upon the annotation and curation of 5,655 ESTs data. SpiroESTdb provides an integrated platform for expressed sequence data, expression dynamics, functional genes, genetic markers including single nucleotide polymorphisms and tandem repeats, gene ontology and KEGG pathway information. Moreover, SpiroESTdb supports easy access to gene pages, such as (i) curation and query forms, (ii) <it>in </it><it>silico </it>expression profiling and (iii) BLAST search tools. Comprehensive descriptions of the sparganum content of all sequenced data are available, including summary reports. The contents of SpiroESTdb can be viewed and downloaded from the web (<url>http://pathod.cdc.go.kr/spiroestdb</url>).</p> <p>Conclusions</p> <p>This integrative web-based database of sequence data, functional annotations and expression profiling data will serve as a useful tool to help understand and expand the characterization of parasitic infections. It can also be used to identify potential industrial drug targets and vaccine candidate genes.</p

Microdevices for extensional rheometry of low viscosity elastic liquids : a review

Extensional flows and the underlying stability/instability mechanisms are of extreme relevance to the efficient operation of inkjet printing, coating processes and drug delivery systems, as well as for the generation of micro droplets. The development of an extensional rheometer to characterize the extensional properties of low viscosity fluids has therefore stimulated great interest of researchers, particularly in the last decade. Microfluidics has proven to be an extraordinary working platform and different configurations of potential extensional microrheometers have been proposed. In this review, we present an overview of several successful designs, together with a critical assessment of their capabilities and limitations

Avoiding Dangerous Missense: Thermophiles Display Especially Low Mutation Rates

Rates of spontaneous mutation have been estimated under optimal growth conditions for a variety of DNA-based microbes, including viruses, bacteria, and eukaryotes. When expressed as genomic mutation rates, most of the values were in the vicinity of 0.003–0.004 with a range of less than two-fold. Because the genome sizes varied by roughly 104-fold, the mutation rates per average base pair varied inversely by a similar factor. Even though the commonality of the observed genomic rates remains unexplained, it implies that mutation rates in unstressed microbes reach values that can be finely tuned by evolution. An insight originating in the 1920s and maturing in the 1960s proposed that the genomic mutation rate would reflect a balance between the deleterious effect of the average mutation and the cost of further reducing the mutation rate. If this view is correct, then increasing the deleterious impact of the average mutation should be countered by reducing the genomic mutation rate. It is a common observation that many neutral or nearly neutral mutations become strongly deleterious at higher temperatures, in which case they are called temperature-sensitive mutations. Recently, the kinds and rates of spontaneous mutations were described for two microbial thermophiles, a bacterium and an archaeon. Using an updated method to extrapolate from mutation-reporter genes to whole genomes reveals that the rate of base substitutions is substantially lower in these two thermophiles than in mesophiles. This result provides the first experimental support for the concept of an evolved balance between the total genomic impact of mutations and the cost of further reducing the basal mutation rate