Vestibular dysfunction in the adult CBA/CaJ mouse after lead and cadmium treatment.

Objectives: The vestibular system allows the perception of position and motion and its dysfunction presents as motion impairment, vertigo and balance abnormalities, leading to debilitating psychological discomfort and difficulty performing daily tasks. Although declines and deficits in vestibular function have been noted in rats exposed to lead (Pb) and in humans exposed to Pb and cadmium (Cd), no studies have directly examined the pathological and pathophysiological effects upon the vestibular apparatus of the inner ear.

Methods: Eighteen young adult mice were exposed through their drinking water (3 mM Pb, 300 µM Cd, or a control treatment) for 10 weeks.

Regional evidence-based practice fellowship program: impact on evidence-based practice implementation and barriers.

This quasi-experimental, pre- and posttest study evaluated the impact of a 9-month collaborative regional evidence-based practice (EBP) fellowship program on practice, attitude, knowledge, and perceived barriers associated with implementation of EBP. Three annual cohorts (N=142) of nurses attending a fellowship program from 2008 to 2010 participated in this study. Paired t tests showed statistically significant increases in practice (+.

Multi-institutional study of barriers to research utilisation and evidence-based practice among hospital nurses.

Aims: The study aims were to explore the relationships between perceived barriers to research use and the implementation of evidence-based practice among hospital nurses and to investigate the barriers as predictors of implementation of evidence-based practice.

Background: Evidence-based practice is critical in improving healthcare quality. Although barriers to research use have been extensively studied, little is known about the relationships between the barriers and the implementation of evidence-based practice in nursing.

The antimicrobial effect of a triclosan/copolymer dentifrice on oral microorganisms in vivo.

Background: The authors compared the in vivo antimicrobial effects on microorganisms from dental plaque, saliva and the tongue in subjects who used a triclosan/copolymer dentifrice and a fluoride dentifrice (control).

Methods: The authors assigned 15 subjects randomly to the control dentifrice or the triclosan/copolymer dentifrice for twice-daily use for one week. They collected samples of plaque, saliva and tongue scrapings six and 12 hours after the final brushing.

Identification of differentially expressed genes in shrimp (Penaeus stylirostris) infected with White spot syndrome virus by cDNA microarrays.

White spot syndrome virus (WSSV) is currently the most important viral pathogen infecting penaeid shrimp worldwide. Although considerable progress has been made in characterizing the WSSV genome and developing detection methods, information pertaining to host genes involved in WSSV pathogenesis is limited. We examined the potential of cDNA microarray analysis to study gene expression in WSSV-infected shrimp.

Improvement in the specificity and sensitivity of detection for the Taura syndrome virus and yellow head virus of penaeid shrimp by increasing the amplicon size in SYBR Green real-time RT-PCR.

Real-time RT-PCR using SYBR Green chemistry uses a green fluorescence dye, SYBR Green I, that binds to double stranded DNA (dsDNA) and exhibits enhancement of fluorescence upon binding to the DNA. The indiscriminate binding ability of SYBR Green I dye to dsDNA often results in non-specific products. We have shown that increasing the amplicon size from approximately 50 to approximately 75-100 bp increases the specificity due to higher melting temperature of the amplicon and also enhances the sensitivity of detection of real-time RT-PCR using SYBR Green chemistry while detecting two RNA viruses in laboratory-challenged shrimp, the Taura syndrome virus (TSV), and yellow head virus (YHV).

Genetic variation and immunohistochemical differences among geographic isolates of Taura syndrome virus of penaeid shrimp.

Taura syndrome virus (TSV) is an important virus infecting penaeid shrimp in the western hemisphere. Genetic variation and immunohistochemical differences of 20 TSV isolates collected from the USA, Taiwan, Mexico and Nicaragua were compared. Capsid protein genes CP1 (546 bp) and CP2 (584 bp) were amplified by RT-PCR and the cDNAs were sequenced.

Isolation of differentially expressed genes from white spot virus (WSV) infected Pacific blue shrimp (Penaeus stylirostris).

To isolate novel cellular factors that are activated or repressed upon WSV infection, the RNA fingerprints of healthy and WSV infected blue shrimp ( Penaeus stylirostris) were compared using the mRNA differential display technique. Thirty-two unique differentially expressed, and one constitutively expressed, cDNA sequences were retrieved. Six of 32 cDNAs showed similarities with the database entries: cDNA 10G32-142 to a shrimp arginine kinase, 22C48-201 to shrimp mitochondrial ATPase gene; 22C47-197, 21G49-203 and 20A55-268 to shrimp ESTs and 20G50-206 to a WSV gene, ORF 116.

The lipopolysaccharide and beta-1,3-glucan binding protein gene is upregulated in white spot virus-infected shrimp (Penaeus stylirostris).

Pattern recognition proteins such as lipopolysaccharide and beta-1,3-glucan binding protein (LGBP) play an important role in the innate immune response of crustaceans and insects. Random sequencing of cDNA clones from a hepatopancreas cDNA library of white spot virus (WSV)-infected shrimp provided a partial cDNA (PsEST-289) that showed similarity to the LGBP gene of crayfish and insects. Subsequently full-length cDNA was cloned by the 5'-RACE (rapid amplification of cDNA ends) technique and sequenced.

Quantitative assay for measuring the Taura syndrome virus and yellow head virus load in shrimp by real-time RT-PCR using SYBR Green chemistry.

Taura syndrome virus (TSV) and yellow head virus (YHV) are the two RNA viruses infecting penaeid shrimp (Penaeus sp.) that have caused major economic losses to shrimp aquaculture. A rapid and highly sensitive detection and quantification method for TSV and YHV was developed using the GeneAmp 5700 Sequence Detection System and SYBR Green chemistry.

RAPD markers as predictors of infectious hypodermal and hematopoietic necrosis virus (IHHNV) resistance in shrimp (Litopenaeus stylirostris).

Random amplified polymorphic DNA (RAPD) fingerprints of two shrimp populations (Litopenaeus stylirostris) were compared to find genetic marker(s) that may be associated with infectious hypodermal and hematopoietic necrosis virus (IHHNV) resistance or susceptibility. Of the 100 10-mer random primers and 100 intersimple-sequence repeat (ISSR) primers screened, five provided markers specific to the Super Shrimp population and three provided markers specific to the wild caught population. The two populations were further characterized for relative viral load (reported as cycle threshold, CT) using real-time quantitative PCR with primers specific to the IHHNV genome.

Hemolymph analysis and evaluation of newly formulated media for culture of shrimp cells (Penaeus stylirostris).

Creation of a shrimp cell line has been an elusive goal. This failure may be due to the composition of the cell culture medium, which may be inadequate to support primary cultured cells. Shrimp hemolymph should contain the nutritional components needed to support cell growth and division.

Comparative seven-day clinical evaluation of two tooth whitening products.

A 1-week study was conducted to compare the tooth whitening efficacy of two carbamide peroxide-based products (one containing 5% carbamide peroxide and one containing 10% carbamide peroxide). In addition, the perception of transient tooth hypersensitivity associated with the use of these products was subjectively evaluated. Sixty participants took part in a double-blind, randomized, parallel clinical study.

Detection and quantification of infectious hypodermal and hematopoietic necrosis virus and white spot virus in shrimp using real-time quantitative PCR and SYBR Green chemistry.

A rapid and highly sensitive real-time PCR detection and quantification method for infectious hypodermal and hematopoietic necrosis virus (IHHNV), a single-stranded DNA virus, and white spot virus (WSV), a double-stranded DNA (dsDNA) virus infecting penaeid shrimp (Penaeus sp.), was developed using the GeneAmp 5700 sequence detection system coupled with SYBR Green chemistry. The PCR mixture contains a fluorescence dye, SYBR Green, which upon binding to dsDNA exhibits fluorescence enhancement.

Nucleotide sequence of 3'-end of the genome of Taura syndrome virus of shrimp suggests that it is related to insect picornaviruses.

Taura syndrome disease, caused by Taura syndrome virus (TSV), is one of the most important viral diseases of penaeid shrimp in the Western Hemisphere resulting in catastrophic disease epidemics in farmed shrimp. We have cloned and sequenced a 3278 bp cDNA representing the 3' end of the TSV genome. Sequence analyses revealed that frame + 2 had the longest open reading (ORF) frame.

Infectious hypodermal and hematopoietic necrosis virus of shrimp is related to mosquito brevidensoviruses.

We purified and sequenced infectious hypodermal and hematopoietic necrosis virus (IHHNV), a small DNA virus of shrimp, from wild Penaeus stylirostris. The virion has a buoyant density of 1.45 as determined by cesium chloride gradient.

Oligomerization of anthrax toxin protective antigen and binding of lethal factor during endocytic uptake into mammalian cells.

The protective antigen (PA) protein of anthrax toxin binds to a cellular receptor and is cleaved by cell surface furin to produce a 63-kDa fragment (PA63). The receptor-bound PA63 oligomerizes to a heptamer and acts to translocate the catalytic moieties of the toxin, lethal factor (LF) and edema factor (EF), from endosomes to the cytosol. In this report, we used nondenaturing gel electrophoresis to show that each PA63 subunit in the heptamer can bind one LF molecule.

Proteolytic inactivation of MAP-kinase-kinase by anthrax lethal factor.

Anthrax lethal toxin, produced by the bacterium Bacillus anthracis, is the major cause of death in animals infected with anthrax. One component of this toxin, lethal factor (LF), is suspected to be a metalloprotease, but no physiological substrates have been identified. Here it is shown that LF is a protease that cleaves the amino terminus of mitogen-activated protein kinase kinases 1 and 2 (MAPKK1 and MAPKK2) and that this cleavage inactivates MAPKK1 and inhibits the MAPK signal transduction pathway.

Targeting HIV proteins to the major histocompatibility complex class I processing pathway with a novel gp120-anthrax toxin fusion protein.

A challenge for subunit vaccines whose goal is to elicit CD8(+) cytotoxic T lymphocytes (CTLs) is to deliver the antigen to the cytosol of the living cell, where it can be processed for presentation by major histocompatibility complex (MHC) class I molecules. Several bacterial toxins have evolved to efficiently deliver catalytic protein moieties to the cytosol of eukaryotic cells. Anthrax lethal toxin consists of two distinct proteins that combine to form the active toxin.

Delivery of antigens to the MHC class I pathway using bacterial toxins.

Cytotoxic T lymphocytes (CTL) recognize antigens derived from endogenously expressed proteins presented on the cell surface in the context of major histocompatibility complex (MHC) class I molecules. Because CTL are effective in antiviral and antitumor responses, the delivery of antigens to the class I pathway has been the focus of numerous efforts. Generating CTL by immunization with exogenous proteins is often ineffective because these antigens typically enter the MHC class II pathway.

Crystal structure of the anthrax toxin protective antigen.

Protective antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthracis, the organism responsible for anthrax. After proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that translocates the toxic enzymes, oedema factor and lethal factor, into the cytosol. PA, which has a relative molecular mass of 83,000 (M(r) 83K), can also translocate heterologous proteins, and is being evaluated for use as a general protein delivery system.

Characterization of lethal factor binding and cell receptor binding domains of protective antigen of Bacillus anthracis using monoclonal antibodies.

Lethal toxin from Bacillus anthracis is composed of protective antigen (PA) and lethal factor (LF). Anti-PA mAbs that neutralized lethal toxin activity, either in vivo or in vitro, identified three non-overlapping antigenic regions on PA. Two distinct antigenic regions were recognized by the four mAbs that neutralized lethal toxin activity by inhibiting the binding of 125I-LF to cell-bound PA.

In vitro processing of anthrax toxin protective antigen by recombinant PC1 (SPC3) and bovine intermediate lobe secretory vesicle membranes.

Protective antigen (PA), an 83-kDa protein produced by Bacillus anthracis, requires proteolytic activation at a tetrabasic site (RKKR167) before it can combine with either edema factor or lethal factor on the cell surface. The complex is then endocytosed and the target cell intoxicated. Previous work has demonstrated that furin, a ubiquitously distributed, subtilisin-like protease, can perform this cleavage.

Proteolytic activation of bacterial toxins by eukaryotic cells is performed by furin and by additional cellular proteases.

Before intoxication can occur, anthrax toxin protective antigen (PA), Pseudomonas exotoxin A (PE), and diphtheria toxin (DT) must be activated by proteolytic cleavage at specific amino acid sequences. Previously, it was shown that PA and DT can be activated by furin. In Chinese hamster ovary (CHO) cells, wild-type (RKKR) and cleavage site mutants of PA, each administered with a modified form of anthrax toxin lethal factor (the N terminus of lethal factor fused to PE domain III), had the following potencies: RKKR (wild type) (concentration causing 50% cell death [EC50] = 12 ng/ml) > or = RAAR (EC50 = 18 ng/ml) > FTKR (EC50 = 24 ng/ml) > STRR (EC50 = 49 ng/ml).

The chymotrypsin-sensitive site, FFD315, in anthrax toxin protective antigen is required for translocation of lethal factor.

The protective antigen (PA) component of anthrax toxin contains two sites that are uniquely sensitive to proteolytic cleavage. Cleavage at the sequence RKKR167 by the cellular protease furin is absolutely required for toxicity, whereas cleavage by chymotrypsin or thermolysin at the sequence FFD315 inactivates the protein, apparently by blocking the ability of PA to translocate the catalytic moieties of the toxins, lethal factor (LF) and edema factor (EF), to the cytosol of eukaryotic cells. To specify the role of the chymotrypsin-sensitive site of PA in the translocation of LF, we altered residues 313-315.